AU4145300A

AU4145300A - Antibacterial agents and method for keeping freshness

Info

Publication number: AU4145300A
Application number: AU41453/00A
Authority: AU
Inventors: Hiroyuki Kobori; Shigeji Kobori
Original assignee: KAISHA TOBU KAGAKU KABUSHIKI; Murakashi Lime Industry Co Ltd
Current assignee: TOBU KAGAKU KK; Murakashi Lime Industry Co Ltd
Priority date: 2000-02-10
Filing date: 2000-04-28
Publication date: 2001-08-20
Also published as: JP3933363B2; JP2001226209A; WO2001058267A1

Description

DESCRIPTION MICROBICIDE AND FRESHNESS MAINTAINING METHOD TECHNICAL FIELD TO WHICH THE INVENTION BELONGS The present invention relates to an antimicrobial agent comprising a water soluble calcium saccharate, to a method for maintaining freshness using the same, and to a coagulant for food, a soil disinfectant, and a growth regulator for vegetation. More particularly, the present invention relates to an antimicrobial agent for hygienically, safely and long-lastingly maintaining freshness of vegetables, fruits, eggs, seeds, flowers after harvest, or food such as bread, cakes, noodle, buckwheat noodle, and rice, meat, fish and the like after fishing or after slaughtering, or for inhibiting acidification of fermented food, to a method for maintaining freshness using the same, and to a coagulating agent for food, a soil disinfectant, and a growth regulator for vegetation using the same. PRIOR ART Antimicrobial agents for food and so forth are used for preventing putrefaction of food due to antimicrobial actions to various microbes. Such use has been made of antimicrobial agents and organic acids such as benzoic acid, acetic acid, sorbic acid, 1 dehydroacetic acid, and propionic acid and salts thereof as well as antimicrobial extracts derived from natural substances and calcined oystershell lime and so forth. Now, problems of health caused by overmuch use thereof are being feared. On the other hand, the storage of fresh vegetables has been performed by maintaining the freshness by means of low temperature storage, or by use of wrapping materials for preventing drying and the time during which the products reach consumers from the producers is within 3 to 7 days, which is a limit. Further, as another method for maintaining freshness, there are used methods that involve both water replenishment and disinfection or sterilization by using hypochlorites, ozonic water, strongly acidic water, 75% alcohol, urea solutions, benzoates, dehydroacetates, propionates, aqueous solutions of calcined oystershell lime and so forth, irradiation of radiation, salting, water spreading, or the like. However, any of methods other than salting fails to give a long lasting effect, so that it is difficult to attain maintenance of freshness for a long time by a method other than cold reservation or cryo preservation. However, cold preservation or cryo preservation is limited in the variety and place. On the other hand, fruits have the problem of nonwaxing in the case of citrus. Although there may be some differences in the method of preservation depending on the kind of fruits, fruits are 2 subjected to low temperature preservation, gas fumigation, or deethylenation prior to their circulation. Development of a method of preservation for a longer time is being desired and a safer processing method is being demanded. However, in some producer countries, products are treated with chemicals that are harmful to human body and sometimes the treated products are imported, which raises a problem. Further, the occurrence of virulent molds is observed. Flowers require very diversified methods of preservation depending on the kind. Sprays other than flowering plants and pot cultures are preserved mainly by prevention of drying and low temperature preservation. Treatments with a pretreatment agent, a posttreatment agent or the like are performed. The influence of ethylene gas is inhibited with STS. Further, there is performed nutritive replenishment by addition of nutrients to the water used for flower arrangement. In the case of fresh fish, inhibition of proteolytic enzymes by enzymatic treatment is performed in some cases. However, mainly cold preservation or cryo preservation is performed for both fresh fish and meat. In the case of cold preservation the limit is 4 days. A long-term storage is performed by cryo preservation. This, however, deteriorates the taste. Fermented food such as fermented soybean (natto), yogurt, bean paste, pickles, and salted fish guts causes putrefaction when the fermentation proceeds too far, so that it has been desired that 3 the fermentation be terminated at a stage where the food retains good taste for subsequent storage. Further, for food utilizing coagulation and solidification such as paste made from konnyaku flour, soybean curd or cheese, storage stability and simplification of production process is being desired, and products containing no additive such as a preservative are being desired. Soil disinfection has been performed by fumigation treatment with methyl bromide. However, due to its ozone layer destruction action, use of methyl bromide is going to be prohibited. As a result a material that causes no additional load on the environment, such as steam sterilization, is being desired. Furthermore, in recent years, demand on planned culture of agricultural crops has led to adjustment of harvesting time. As a result, accelerated culture and retarding culture are being performed. However, the chemicals used may contain undesirable substances and hence safer retarding agents have been demanded. Antimicrobial agents as food additive may use substances harmful to human body and hence safer antimicrobial agents have been demanded. Furthermore, about 40% of storefront goods of vegetables, fruits, flowers, fish, meat, or egg are deadstock due to a decrease in freshness and therefore discarded. Under the circumstances, prolongation of storage time as much as possible has a great economical effect. Also, an effective countermeasure is being demanded for preventing food poisoning that is 4 multiplicative in recent years. The chemicals conventionally used for maintaining freshness mostly include synthetic chemicals and have problems on the safety to human body. For example, prohibited chemicals may sometimes be used covertly. Fumigants cause environmental problems relating to prevention of global warming. Moreover, in recent years, ozonic water has also been used in order to maintain freshness. However, generation of peroxides accompanied by this treatment has been overlooked and only its disinfecting action has been accentuated. The existence of oxidation products is neglected only based on the condition that no residue is present in hydrogen peroxide water. Many of these chemicals of which residual toxicity including agricultural chemicals are questioned have been used in various manners behind watch by consumers. Agricultural chemical-free cultivated vegetables and the like have been produced as reaction thereto. For the reasons as described above, antimicrobial agents that are safe to human body must meet the conditions that they are nontoxic to human body, that after the treatment they are readily decomposed so as not to cause environmental pollution, and that they are substances that can retain antimicrobial property for a certain period of time but do not deteriorate taste or nutritive values. Such substances are demanded as antimicrobial agents. 5 Further, a method for maintaining freshness by wrapping includes vacuum wrapping, use of deoxygenating agent, nitrogen gas purging, heat wrapping and so forth. Posttreatment of wrapping material causes the problem of disposal of wastes. To solve these problems, development of a substance has been demanded that can perform maintenance of freshness by synergism of three kinds of actions, that is, antimicrobial effect, humectant effect and ethylene inhibiting action, which is quite different from the conventional method. Furthermore, in the field of agriculture, there has been few means that solve by a safe method the problem of using fumigation treatment as a method of performing prevention of sequential cropping failure of soil and soil disinfection. Therefore, a new method for soil regeneration is being desired. Still further, chemicals used for accelerated culture and retarding culture of agricultural crops include undesirable substances so that safer retarding agents are being desired. As the countermeasure for this, a method of decreasing the physiological activity of vegetation without performing inhibition of growth hormone thereof is desirable and physical inhibition is preferred to chemical inhibition as a means therefor. Accordingly, the present inventors have made extensive studies with a view to solving the above-mentioned problems. As a result, paying attention to the fact that various organic acids 6 or organic acid salts that have been conventionally used as antimicrobial agents have stronger antimicrobial property and are more useful for the storage of food as they contain more non associable molecules, and also paying attention to water-soluble calcium saccharates that generate non-associable molecules by a small extent of dilution with water on the side of alkalinity and continuously generate OH ions upon hydrolysis to increase pH, they have found out that the phenomenon can be utilized as an antimicrobial agent. They have found out that the water-soluble calcium saccharates produced from various saccharides, calcium oxide or hydroxide, ormagnesiumoxide orhydroxide in copresence of calcium, are diluted and hydrolyzed with the moisture that vegetables, fruits, seeds, flowers, meats, eggs, fishes or the like have to thereby generate OH~ ions. The disinfecting power of OH' ions inhibits the proliferation of microbes. The water-soluble calcium saccharates have antimicrobial property as potent as about 45 times that of calcined oystershell lime. Further, they have found out that the water-soluble calcium saccharate readily react with carbon dioxide gas in the air or in a carbon dioxide gas atmosphere to form carbonates and form a thin film of aragonite. This thin film is an antimicrobial thin film that has a pore diameter small enough to prevent invasion of microbes and has a porosity of about 30%, at which the respiration of vegetables, fruits, flowers and so forth 7 is weakly inhibited, so that it can retain the moisture in the target item. Therefore, the water-soluble calcium saccharates have freshness maintaining ability as strong as that of wrapping materials. They have also found out that the water-soluble calcium saccharates have ethylene inhibitory effects and growth regulating action for vegetation. Furthermore, they have found out that the water-soluble calcium saccharates have fermentation inhibition action by controlling the microbes in fermented food, protein or polysaccharide coagulating action and soil disinfecting action. The present invention has been achieved based on these discoveries. DISCLOSURE OF THE INVENTION That is, the present invention is to provide an antimicrobial agent comprising a water-soluble calcium saccharate obtained by reacting one member or more members selected from the group consisting of saccharides with calcium oxide or hydroxide, or magnesium oxide or hydroxide in the copresence of calcium, in the presence of water; a method for maintaining freshness of food, seed or flower, comprising using an aqueous solution including the water-soluble calcium saccharate; a method for maintaining freshness of food, seed or flower, comprising treating an aqueous solution including the water-soluble calcium saccharate with food, seed or flower, and then carbonating the aqueous solution to form a calcium carbonate/saccharide complex film on the surface of food, 8 seed or flower; and a coagulating agent for food, soil disinfectant and growth regulator for vegetation, comprising a water-soluble calcium saccharate. The present invention provides uses of a water-soluble calcium saccharate obtained by reacting at least one member selected from the group consisting of saccharides with calcium oxide or hydroxide, or magnesium oxide or hydroxide in the copresence of calcium, in the presence of water, or an aqueous solution thereof as an antimicrobial agent, a freshness maintaining agent for food, seed or flower, a coagulant for food, a soil disinfectant or a growth regulator for vegetation. That is, the present invention provides a method for achieving the uses by applying the water-soluble calcium saccharate to places where these uses are desired. Further, the present invention provides an antimicrobial composition comprising the above-mentioned water-soluble calcium saccharate and at least one member selected from the group consisting of an osmotic pressure adjusting agent, a pH adjusting agent, a surfactant, and a spreading agent. In the present invention, the term "water-soluble calcium saccharate" refers to calcium saccharate that is dissolved in water at ambient temperature. The antimicrobial agent of the present invention is obtained by reacting saccharides with calcium oxide or hydroxide, or magnesium oxide or hydroxide in the copresence of calcium, through 9 water. To this, optionally an aqueous solution containing two or more of osmotic pressure adjusting agents such as common salt and halides, phosphates and sulfates of alkali metals, organic acids, urea and so forth as secondary components may be added. Further, as third components, pH-adjusting agents such as organic acids, amino acids, mineral acids may be selected and added depending on the purpose to decrease pH to about 8.5 since the calcium saccharate gives high pH. To impart spreadablity, a suitable amount of hydrophilic emulsifying agent having an HLB of 10 or more, such as sucrose fatty acid esters and glycerol fatty acid esters may added. Alternatively, there may be added polyvinyl alcohol (PVA), vinyl acetate, hydroxycellulose, starch, carboxymethylcellulose (CMC) alginic acid, agar, gelatin, paste made from konnyaku flour, or the like as a sizing agent. Furthermore, the calcium saccharate itself maybe diversified by use of various types of saccharides depending on the purpose and mixtures of two or more calcium saccharides may be used. Use of such mixtures makes it possible to prepare good calcium saccharate aqueous solutions and further vary the film nature of the carbonated films. Reacting carbon dioxide gas in the air or carbon dioxide gas with the calcium saccharate treated product to form a film of calcium carbonate or magnesium carbonate in a short time and in addition reducing the influence of high pH on the calcium 10 saccharate by neutralization can prevent the denaturation of the treated product. Fermented food produces organic acids and causes the phenomenon of acidification to occur, thus deteriorating the taste as the fermentation proceeds. As a result, it is often the case that preferably the fermentation is inhibited by performing the fermentation under moderate fermentation conditions. Addition of the water-soluble calcium saccharate of the present invention to such a fermentation terminating agent inhibits fermentation to improve storage stability. In the production of paste made from konnyaku flour, lime is often used and the residual lime is removed by boiling the paste in water for a long time. However, use of the water-soluble calcium saccharate of the present invention enables one to extract the lime with water without performing boiling at all. The water-soluble calcium saccharate of the present invention can also be used as a coagulating agent in the production such as bean curd (tofu) and cheese and the excessive calcium saccharate is effective in the prevention of putrefaction. DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the present invention will be illustrated in detail by reference to embodiments. The saccharide that is one of starting components of the aqueous calcium saccharate used in the present invention means 11 polysaccharides; oligosaccharides such as disaccharides, trisaccharides, tetrasaccharides and so forth; monosaccharides; sugar alcohols and so forth. The polysaccharide includes water-soluble dextrin, glucan, pullulan, amylose, xanthan gum, hydroxycellulose, CMC, mannan, gum Arabic, guar gum, glycyrrhizin, pectin and so forth. The monosaccharide and oligosaccharide include, for example, sucrose, glucose, fructose, maltose, starch syrup, xylose, lactose, sorbose, palm sugar, oligosaccharides, coupling sugar, neosugar and so forth. As the liquid sugar, sucrose type, invert sugar type, isomerized type, and mixed liquid sugar and in addition, sugar alcohols such as maltitol, sorbitol, mannitol, paratinitol may be used singly or two or more of them may be used in combination. These saccharides are used as mixtures of two or more of them in order to improve the water solubility thereof with one of them being preferably 10 to 40% by weight and another being preferably 90 to 60% by weight. In the case where three or more saccharides are mixed with each other, it is preferred that similarly they are used in disproportionate mixing ratios so that solubility in water can be readily attained. In the case where the saccharides are used singly, it is preferred that the pH be adjusted to a lower value than that of a single saccharide calcium saccharate. To obtain water soluble calcium saccharates, preferred are those that contain a small amount of carbonic acid salt, phosphoric acid salt or a 12 fatty acid salt. Those having apH lower than those of usual calcium saccharates have a higher solubility in water. In the present invention, it is particularly preferred that at least one member selected from monosaccharides and oligosaccharides and at least one member selected from sugar alcohols and polysaccharides are used in combination. The calcium saccharate used in the present invention can be obtained by reacting calcium oxide or hydroxide, or magnesium oxide or hydroxide in coexistence with calcium, with a saccharide using an aqueous solution or a small amount of water. Also, the present invention may be practiced by improving the known calcium saccharate synthesis method disclosed in J.E. Mackenazie, J.P. Quin, J. Chem. Soc., 951 '(1930). The calcium saccharate used in the present invention is a water-soluble calcium saccharate and is hydrolyzed in water to exhibit antimicrobial property. Depending on the type of saccharides, dicalcium saccharates and tricalcium saccharates can be obtained, which have high degree of crystallinity. These are not water-soluble and are not hydrolyzed in water to fail to generate active OH~ ions, so that they have no antimicrobial property. Water-soluble calcium saccharates are hydrolyzed by dilution with water. Their hydrolyzability varies depending on the type of saccharides. Its tendency is sugar alcohol > xylitol > sucrose > 13 glucose > fructose > dextrin > glucan > pullulan > amylose > mannan and so forth. The saccharides having weak hydrolyzability such as maltose have low antimicrobial property. However, calcium saccharates having higher reactivity with calcium and magnesium are more difficult to be hydrolyzed. When they are carbonated, they form a dense carbonate film so that they are useful for forming transparent films that are less susceptible to whitening. Accordingly, use of mixtures of two or more types while adjusting ratios thereof can give rise to excellent carbonate films. Since there is a high possibility that the saccharides after the hydrolysis or carbonation of calcium saccharates serve as nutrient sources for bacteria, they are preferably non biodegradable saccharides, most of which belong to sugar alcohols. For this reason, in the case where a long term antimicrobial property is required, selectively using sugar alcohols or using a mixture of two or more saccharides containing them in large amounts with adjusting the mixing ratios enables to impart thereto long lasting antimicrobial property after the hydrolysis or carbonation of the calcium saccharates although this is not the case when only temporary antimicrobial action is contemplated. The calcium oxide or hydroxide, or magnesium oxide or hydroxide in coexistence with calcium, which is used in producing reaction of the calcium saccharates, includes preferably limes, 14 including unslaked lime, slaked lime, calcined dolomite, dolomite plaster, calcined shell lime, gypsum and so forth. Oxide or hydroxide of simple magnesium does not react with saccharides. However, when magnesium oxide or hydroxide is used in combination with calcium, reaction occurs readily so that saccharates of calcium/magnesium complex salts can be obtained. In this case, the proportion of calcium to magnesium is preferably calcium/magnesium (weight ratio) = 1/1 to 3/1. The water-soluble calcium saccharates produced as described above have specified pH values that may vary depending on the type of the saccharide, being generally 12.5 or less, which are high. To facilitate hydrolysis, to protect the target substance to be treated from the influences of strong alkalinity, or to give no adverse influence on strongly acidic substances, a means for solving this may be taken, which performs pH adjustment by addition of an organic acid such as acetic acid or citric acid or amino acid, or a mineral acid such as phosphoric acid, carbonic acid, hydrochloric acid, or sulfuric acid to the calcium saccharate to lower pH to at least about 8.5. However, there is a limit on pH since calcium and magnesium will be released at pH values lower than the above. To provide a method for preventing taste, odor or feeling upon eating of the substance to be treated from changing, usually the water-soluble calcium saccharate aqueous solution use highly purified raw materials, which preferably contain no heavy metal 15 nor substance that is accompanied by side reactions, such as protein, aldehyde or pigment. A desirable method for producing the antimicrobial agent of the present invention is a method of suspending 8 to 10 parts by weight, preferably 10 parts by weight, of calcium oxide or hydroxide, or magnesium oxide or hydroxide in coexistence with calcium, in 100 parts by weight of water, and adding thereto 40 to 70 parts by weight, preferably 40 to 50 parts by weight, of saccharide with stirring. The stock solution obtained here is diluted with water to usually 5 folds or more to make a treating solution. In this case, commercially available saccharides are susceptible to Maillard reaction or caramel formation to give odor or coloring, so that it is preferred to use purified starting materials in order to prevent the side reactions thereof from occurring. The water-soluble calcium saccharate aqueous solution diluted with water to 5 folds causes hydrolysis reaction for every dilution up to 200 folds and the antimicrobial power of OH~ ions lasts. Therefore, selection of a treating concentration matching the nature of the target substance to be treated is possible. The water-soluble calcium saccharates have antimicrobial property effective to gram-negative facultative anaerobic bacteria, gram-negative aerobic bacteria, gram-negative anaerobic bacteria, gram-negative cocci, bacillococci, gram-negative anaerobic cocci, spirochete, spirilla, gram-positive cocci, sporogenous bacteria, 16 gram-positive sporeless cocci, actinomycete, mycoplasma, rickettsia, fungi, oral bacteria, chlamydia and so forth although their bacteriostatic concentrations may differ. The water-soluble calcium saccharates are not effective to viruses but have a wide antimicrobial spectrum. The water-soluble calcium saccharates are ef fective not only to the above pathological microbes but also to yeast, lactic acid bacteria, soil bacteria, molds and so forth. They also exhibit lasting antimicrobial property against falling bacteria upon food processing. As a method for further imparting fast-activeness to the aqueous solution of water-soluble calcium saccharate having a wide antimicrobial spectrum as described above, alcohols such as ethanol, isopropyl alcohol (IPA) and propylene glycol may be added and also disinfectant such as cresol, phenol and invert soap may be added. However, to provide antimicrobial agents for food, addition of alcohols is preferable. This can give rise to antimicrobial agents that are also effective to viruses. Since the water-soluble calcium saccharates in accordance with the present invention are alkaline, they are effective to most of gram-negative bacteria in contrast to the conventional antimicrobial agents that have narrow antimicrobial spectra on the side of acidity. Although they are decomposed with acids to some extent, they have the ef fect of retaining stable antimicrobial power 17 for a long time unlike other antimicrobial agents that react with the material to be treated to cause decomposition reaction resulting in the loss of the antimicrobial property. Furthermore, they have high safety, exhibiting LDO =1,860 g/kg (mouse, intraabdominal), so that they can be administered in large amounts. The antimicrobial property of a suspension of calcined oystershell lime that is closest to the present invention is such that it is effective to gram-negative bacteria. The calcined oystershell lime is used in the form of a suspension and in a concentration of 0.14%, which is not so different from that of slaked lime. As a result, it has low antimicrobial power and gives a very small amount of Ca(OH) 2 slowly released from water-soluble CaO as compared with the water-soluble calcium saccharates. The antimicrobial property of calcined oystershell lime suspension is about 1.5 times that of slaked lime. The water-soluble calcium saccharates of the present invention can impart antimicrobial property in both manners of addition. One is to add them into food and another is to add to the outside of food. The freshness of vegetables, fruits, seeds, flowers, meats, eggs, fishes and so forth is decreased by infection of bacteria, evaporation of water, air oxidation, a decrease or cessation of physiological activity, ripening hormone, lytic enzyme and so forth. For preventing this, low temperature preservation is suitable. In 18 situations where most of items are unsuited for preservation by refrigeration and cryo preservation is difficult to be applied due to destruction of cell membranes, salting or the like method is performed. The freshness maintaining mechanism that uses the water soluble calcium saccharates according to the present invention includes a preservation effect due to the antimicrobial property and liquid wrapping action thereof, and in addition an effect of decreasing biological activity of the treated matter by film formation. Treating vegetables, fruits, seeds, flowers, meats, eggs, fishes and so forth with the water-soluble calcium saccharates of the present invention results in the dilution and subsequent hydrolysis of the water-soluble calcium saccharates with the water contained therein to generate ions: R-Ca(OH) 2 + nH 2 O - R + Ca- + 20H', which causes a temporary increase in pH. A given time after this reaction, the reaction of R-Ca (OH) 2 + nH 2 O -- R + Ca (OH) 2 takes place and the phenomenon that pH is returned to the original value occurs. If continuous replenishment of water is performed during this, the hydrolysis of calcium saccharate will proceed to generate potent antimicrobial property, which inhibits the growth of bacteria. If reaction with carbon dioxide gas occurs during this reaction the calcium ions are readily carbonated to form a film 19 of calcium carbonate. In contrast thereto, the carbonation of the calcium saccharate that has not been hydrolyzed proceeds slowly so that film formation takes a long time. The carbonated film is such that when thinly coating on glass immediately after 10-fold dilution, the water-soluble calcium saccharate aqueous solution obtained above gives a thin film having a thickness of 0.4 P, a pore diameter of 0.01 P, a porosity of about 30%. Accordingly, a thin film is formed that allows the treated product to respire but permeate less moisture so that it has a moisture retention action. In view of this, formation of a carbonated film by hydrolysis at an appropriate concentration of calcium saccharate can give rise to a protective film that has not been heretofore obtained. Various items to be treated differ in the properties of cell membrane and have respective specific osmotic pressures, and their treatment is complex. Therefore, vegetables, fruits, flowers, eggs, and vegetation have specific respiratory properties and hence treating concentrations are adjusted to appropriate ones. In particular, meat and fish are susceptible to the influence of osmotic pressure to a great extent, so that addition of salts that adjust the osmotic pressure is preferable. Addition of common salt, potassium chloride, magnesium chloride or the like in an amount equivalent to and more than the concentration of physiological saline and equivalent to or less than the concentration of sea water can prevent the discoloration and destruction of mucous membranes. 20 As for the maintenance of freshness of foliage vegetables, prevention of proliferation of microbes by use of antimicrobial agents and in addition thereto prevention of dryness by moisture retention afford the maximum freshness maintaining effect. Those varieties that have more complex leaf forms, smaller leaf thicknesses and smaller leaf surface strengths are more vulnerable to dryness. Accordingly, although the treatment with the water-soluble calcium saccharate aqueous solution alone is effective for maintaining freshness for a short time, a method of adding urea, ammonium sulfate, alum, chondroitin, glycerol, propylene glycol or the like used as a humectant in order to further increase the moisture retention may be used. Also, to aid film formation, PVA, vinyl acetate, CMC, hydroxycellulose or the like, which is used as a food additive, may be used as a spreading agent. The spreading agent is used in order to form films effective to varieties having water repellent property since some kinds of vegetables, fruits, flowers and so forth have wax on the surface thereof. Foliage vegetables when treated with solutions at a dilution ratio equal to or greater than 10-fold diluted water-soluble calcium saccharate aqueous solution, can be preserved in the air for 24 hours or more under the conditions of a temperature of 25 0 C, a humidity of 65%, and a wind speed of 2 m. However, in the case of untreated lettuce, spinach and so forth, the preservation under 21 the conditions leads to the start of wilting in about 45 minutes and the original state cannot be returned even by spraying water when the wilting reaches a drying loss of 3.5% or more. Cut vegetables are adjusted so as to have a viable microbial cell number of 100,000 per g at the time of shipment. However, when the cold retention time at 5 0 C or less is long, the viable cell number readily increases to 1,000, 000 per g or more, thus causing food poisoning. Therefore, for the purpose of dezymotizing, washing with chlorine based chemicals and ozone, strongly acidic water or the like is performed. However, these have short time of bacteriostatic action and are ineffective to spores so that there is high possibility that the proliferation of bacteria readily occurs. The water soluble calcium saccharate aqueous solution of the present invention when in contact with such vegetables that contain moisture readily undergoes hydrolysis to release antimicrobic OH~ ions to cause the antimicrobial property to last for a long time so that the proliferation of bacteria can be inhibited. For example, the cut vegetable treated with a 20-fold diluted water-soluble calcium saccharate aqueous solution has a viable cell number of 15,000 per g after standing at 5"C for 10 days. Taking an example of Chinese radish, Chinese radish in 10% saline cannot inhibit the proliferation of molds and bacteria but Chinese radish in a 10-fold diluted water-soluble calcium saccharate aqueous solution exhibits preserving property such that 22 6 months' immersion therein at ambient temperature does not result in putrefaction. Komatsuna (a kind of Chinese cabbage (Brassica campestris)) immersed in 10 times the volume of 10-fold diluted water-soluble calcium saccharate aqueous solution can be preserved for 6 months by immersion at ambient temperature similarly to Chinese radish. During this, there is neither discoloration nor change in shape and the vegetable retains original shape and becomes stiff. However, when passed through hot water, it gives boiled food that shows no change in taste. Fruits, root vegetables such as potato, taro, sweet potato, onion, yam and so forth are relatively strong against drying but are vulnerable to molds, diseases and pests during storage. Treating them with the water-soluble calcium saccharate aqueous solution of the present invention to coat the surface therewith enables long term preservation. Hitherto, to preserve fruits for which cryo preservation is difficult, for a long time, preservation at a low temperature and that in a carbon dioxide gas atmosphere are used and the fruits are stored by a method that decomposes or adsorbs ethylene gas. However, this method has a limitation. Instead, treatment of the fruits with the water-soluble calcium saccharate aqueous solution. of the present invention prior to cryo preservation enables long term preservation. This is because the water-soluble calcium saccharate aqueous solution has not only antimicrobial property 23 and moisture retention by coating of fruits but also has an effect of participating in the respiratory action to inhibit ethylene. This is demonstrated by the amount of ethylene gas generated. Therefore, treatment of citrus such as tangerine orange, sudachi orange (Citrus sudachi) , orange, lemon, hassaku orange (Citrus hassaku) , iyokan orange (Citrus iyo) , and amanatsu orange (Citrus amanatsu) with 5 to 10% by weight water-soluble calcium saccharate aqueous solution can ensure improvement of putrefaction and prevention of an increase in sugar content until maturity is reached as compared with untreated items. Thus, there arises a difference of 4 months in keeping quality. This tendency is also remarkable in the case of strawberry, pear, apple, peach, grape and so forth. Use of such water-soluble calcium saccharate aqueous solution yielded a difference of 2% by weight or more only in a drying loss change as compared with the conventional preservation method, without causing any change in taste and flavor. As described above, for root vegetables such as potato, taro, sweet potato, onion and yam, for which a long term preservation is intended, citrus such as tangerine orange, sudachi orange, orange, lemon, hassaku orange, iyokan orange and amanatsu orange, pear, apple, peach, grape and so forth, a method of forcibly forming a carbonate film by use of carbon dioxide gas in the air after the treatment with the water-soluble calcium saccharate aqueous solution is more effective. The preservation conditions of a low 24 temperature of 5 0 C or less and a humidity of 85% or more in a saturated carbon dioxide gas atmosphere enables preservation to be extended till the production stage in next year. Commercially available meat includes beef, pork, mutton, fowl and so forth. Slicing results in discoloration and increasing the elution of broth and shortens the life of meat. Treatment of meat with a 10-fold or more water-soluble calcium saccharate aqueous solution which is a mixed water-soluble saccharate aqueous solution containing two or more saccharides selected from sugar alcohols, reducing saccharides and oligosaccharides, to which 0.9 to 6.0% by weight common salt is added, not only can prevent the discoloration and the elution of broth but also can prevent putrefaction and develop reddish color so that long term meat preservation can be performed. Similarly, use of the water-soluble calcium saccharate aqueous solution with adjusting the concentration depending on the kind of fish enables one to maintain the freshness thereof although the treatment process somewhat differs from the above. In particular, injection of the 10-fold or more diluted water soluble calcium saccharate aqueous solution that is the above-mentioned mixed water-soluble calcium saccharate aqueous solution, to which 0.9 to 6.0% by weight of common salt is added, into the internals that readily undergo putriefaction or dipping the internals therein inhibits proteolytic enzymes in the internals, which is effective 25 for preventing the putrefaction. The mucous membrane of fish is prevented from being denatured at a saline concentration near that of the brine and no whitening occurs. Therefore, it is particularly effective to the processing of fish that tends to undergo reduction in freshness, such as sardine. For example, desiccate of secondary processed products of fish, smoked products, fish guts pickled in salt, seasoned products can be prevented from a reduction in freshness during their processing. Also, for preventing oxidation and proliferating germs of various sorts after the processing, the formation of antimicrobial film enables long term preservation. The method of treating with the water-soluble calcium saccharate aqueous solution of the present invention includes mixing, dipping, spraying, and bubbling. These may be selected appropriately depending on the shape of food, the kind of vegetable, fruit, flower and so on. To facilitate the treatment, it is preferred that a spreading agent (tackifier) and/or a surfactant be added to the above aqueous solution. The water-soluble calcium saccharate aqueous solution may be converted into re-water-soluble powder by using a spray drier or the like. The spreading agent (tackifier) is used to treat those having water-repellency or attachment failure depending on the kind of vegetables, fruits, flowers and so forth. It may be added to the above -mentioned aqueous solution in an amount of 0. 01 to 1% by weight. The spreading agent (tackifier) includes, for example, 26 carboxymethylcellulose, methylcellulose, polyvinyl alcohol, starch, starch phosphoric acid ester, gelatin, mannan, agar and so forth. Also, it is preferred that the surfactant be used in combination with the above-mentioned spreading agent (tackifier). For example, hydrophilic emulsifying agents having an HLB 10 or more, e.g., nonionic surfactants such as sorbitan esters, monoglycerides, polyoxypropylene sorbitan esters, sucrose fatty acid esters, glycerol fatty acid esters, and polyoxyethylene alkyl ethers are used. The surfactant is added in an amount of 0.01 to 0.5% by weight to the above-mentioned water-soluble calcium saccharate aqueous solution, and bubbled together with a large amount of air when it is used. The bubbles shield the water-soluble calcium saccharate aqueous solution from the open air and as a result the freshness is maintained by the humectant and antimicrobial actions. The antimicrobial agents of the present invention may be utilized for almost all the kinds of vegetables, fruits, flowers and so forth set forth below. For example, mention may be made of not only root vegetables such as Chinese radish, carrot, onion, potato, and burdock, but also foliage vegetables such as cabbage, Chinese cabbage, spinach, broccoli, komatsuna, lettuce, Chinese vegetables, white radish sprouts, beefsteak plant, leek, bean sprouts, Asparagus, Western vegetables, furthermore crops, such 27 as vegetable string bean, tomato, eggplant, cucumber, green pepper, strawberry, kidney bean, oriental melon, melon, watermelon, and mushrooms such as shiitake mushroom (Lentinus edodes), nameko mushroom (Phoriota nameko), velvet shank (Flammulina velutipes), maitake (Grifola frondosa) , oyster mushroom (Pleurotus ostreatus), Judas-ear (Auricularia auricura), as well as citrus such as tangerine, lemon, Chinese citron, hassaku orange, navel orange, and orange, southerly fruits such as banana, mangosteen, papaya, avocado, kiwi, and domestic products such as cherry, grapes, pear, apples and so forth. Further, the antimicrobial agents of the present invention may also be utilized for edible wild plants, seaweed and so forth. Appropriate differences in treating concentration may be required. However, mostly surface treatments are concerned so that for most kinds of target except for bean sprouts, the treatment can be performed with 5- to 20-fold dilutions. Treatment with carbon dioxide gas in the air or treatment in a stream of about 30% carbon dioxide gas to form an accelerated carbon dioxide film results in a reduction in the influence of high pH of the water-soluble calcium saccharate, which is also useful in preventing denaturation so that no adverse influence is given to the liquidity of the inside of the treated item. In the case of flowers, it is most effective to use the antimicrobial agents of the present invention for pot cultures and 28 cut flowers for flower arrangement. The antimicrobial agents of the present invention are effective for the control of the flowering period and prolongation of flowering time. They can be used for flowers of orchids, bulbous plants, rhizocarpic plants, roses, annual plants, and perennial plants. In particular, inhibition of ethylene in flower arrangement is used as a method for improving the durability of flower and STS, aminooxyacetic acid and so forth are used therein. However, these inhibit blooming of flower buds so that they are ef fective to already bloomed flowers but are not suitable for continuous blooming. Treatment of flower arrangement with the water-soluble calcium saccharate aqueous solution in an appropriate concentration it can serve as a treating agent for flower arrangement that allows flower buds to bloom unlike the above-mentioned ethylene inhibitor. This action is attributable to the ethylene inhibiting action and life inhibiting action of cut flowers for flower arrangement (respiration reducing effect because of carbonate film) that occur simultaneously. It has been found out that treatment of vegetation with the water-soluble calcium saccharate aqueous solution of the present invention causes temporary growth regulating phenomenon, as a result of which the growth is stopped. Utilizing this action, harvest and flowering period of agricultural crops can be retarded so that planned culture can be realized. 29 Growth regulators are roughly grouped into five groups depending on their effects, i.e., gibberellin inhibitors that inhibits elongation, oxine activators that prevent fruit drop, dwarfing agents, top pinching sucker inhibitors, and sucker forming agents. The inhibitory action of the water-soluble calcium saccharate of the present invention to the vegetation is concerned with the top pinching sucker inhibitory action and elongation inhibitory action. It temporarily inhibits the growth and hence it dose not have a long-term growth inhibitory effect as dwarfing agents have. For this reason, by adjusting the treating concentration of the water-soluble calcium saccharate, inhibition of growth of vegetation for 7 to 28 days may be performed although there may be some differences depending on the kind of the vegetation. This action is based on inhibitory effects composed of the inhibition of respiratory action of vegetation and water absorption from the root by the carbonate film of vegetation formed by the treatment with the water-soluble calcium saccharate of the present invention. Further, using the water-soluble calcium saccharate aqueous solution of the present invention as an antimicrobial agent in seed treatment and performing specific gravity control instead of common salt, the water-soluble calcium saccharate aqueous solution of the present invention can be used in differential selection of seeds. In this case, however, concentration control is necessary since 30 there is observed a germination inhibitory effect. The water-soluble calcium saccharate aqueous solution of the present invention has an ice point depression effect and also has an antimicrobial action, so that it can be utilized as a refrigeration treating agent for edible animals and plants. In particular, in a method for refrigerating fresh fish, fowl, pork, beef, mutton and so forth in which dipping in the water soluble calcium saccharate aqueous solution of the present invention is performed prior to refrigeration, the water-soluble calcium saccharate aqueous solution of the present invention has the feature of stopping the elution of broth, which maintains the freshness upon defreezing. Also, in ice temperature preservation of fresh fishes and fresh meats, the water-soluble calcium saccharate aqueous solution of the present invention is characterized by having an action of inhibiting the propagation of bacteria and the activity of proteolytic enzymes contained in the internals to prevent the reduction in the freshness thereof. In the processing step such as processing of cut vegetables and butcher's meat, a suitable method for decreasing the cell number of falling bacteria and food poisoning bacteria has not been achieved by any method other than improvement of air environment in the processing room and washing raw materials and washing the machine and apparatus are decisive factors. In particular, for washing raw materials, aseptic washing that does not change the 31 taste is important. There is substantially no taste nor odor in treating liquors which is 10-fold or more dilutions of the water-soluble calcium saccharate aqueous solution of the present invention, being suitable as the above-mentioned washing agent. The osmotic pressure of such treating liquors 1/3 time as high as that of common salt causes no change in taste when they come into contact with food. The preservation effect of the water-soluble calcium saccharate aqueous solution of the present invention on vegetables, fruits, meats, and fishes dipped therein is good enough to provide a new long-term preservation method in place of the conventional salting so that the water-soluble calcium saccharate aqueous solution of the present invention can be used for various food processing applications. In particular, there are many kinds of secondary processed products of food and goods containing many kinds of preservatives are circulated. This is also a field where the safety of preservatives is most questioned. In a method in which the water-soluble calcium saccharate of the present invention is used for this application and pretreatment or posttreatment is performed, a means is provided that replaces preservation method using processing method such as salting, confection, retorting or the like. The salting or heat treatment method changes the shape of food and cannot provide preservation while retaining original shape. In contrast, preservation in a 32 solution of water-soluble calcium saccharate of the present invention makes it possible to achieve preservation while retaining original shape, which provides a means for preserving color, taste, flavor and so forth as they are. Fermented food such as pickles, fish guts pickled in salt, cheese, yogurt and fermented soybeans tend to sometimes undergo fermentation to cause acidification. Addition of a small amount of water-soluble calcium saccharate of the present invention in order to inhibit the fermentation stops the fermentation and enables one to perform low temperature storage in a state where the taste is maintained good. As a result, products with reduced salt content can be obtained. In the case of dried fish, the trend in recent years shows that sun-dried fish products have decreased and forcibly dried fish products have increased instead. A method of injecting a suitable amount of water-soluble calcium saccharate of the present invention into the internals of blue fish and subjecting the fish to dipping treatment on the surface enables one to make low salt dried fish in a refrigerator. As a result, processed products with retaining original taste can be obtained. This method protects smoked meat or fish, dried products, delicacy processed food and so forth from microbes, which is useful in the prevention of oxidation of fatty acids by means of the carbonated film. The water-soluble calcium saccharate of the present invention, 33 unlike the conventional calcium saccharate, readily releases calcium or magnesium to coagulate proteins or polysaccharides. A solution of konnyaku obtained by heating an aqueous suspension of konnyaku can be readily coagulated by the addition of water-soluble calcium saccharate thereto. Although addition of calcium saccharate to soybean milk to coagulate it to form bean curd, usual water-insoluble calcium saccharate is stable and hence calcium or magnesium is difficult to release. It is disadvantageous to use water-insoluble calcium saccharate as a coagulant. Further, the water-soluble calcium saccharate of the present invention has high solubility in water and the coagulated konnyaku does not have to be subjected to heat treatment for decocting the lime. As a result, the production step is simplified and putrefaction hardly occurs. In the case of bean curd, those obtained by using the water-soluble calcium saccharate of the present invention have antimicrobial property in contrast to those obtained with bittern or other coagulants, so that products that are hardly putrefied can be obtained. In the treatment of vegetables and fruits according to the present invention, the method of carbonating various water-soluble calcium saccharates includes carbonation in the air and forcible carbonation. In the case where the carbonation is carried out with 30 to 50% carbon dioxide at a humidity of 80 to 85%, it is preferred to use a low temperature carbonation apparatus that can perform 34 carbonation by cooling to about 50C. This apparatus can realize in 2 hours the carbonation that usually takes 48 hours by carbonation with carbon dioxide gas in the air. By increasing the carbonation temperature to 20 0 C, the carbonation is completed within 1 hour. EXAMPLES Hereinafter, the present invention will be illustrated in more detail by reference to examples. However, the present invention should not be limited thereto. All the "parts" and "%" in the examples mean "parts by weight" and "% by weight", respectively. Example 1 40 parts of beet granulated sugar, 100 parts of water and 10 parts of lime powder were reacted at room temperature for 4 hours. The obtained water-soluble calcium saccharate solution was diluted with water to 20 folds and the solution was coated on a nutrient broth medium. A salmonella strain was inoculated on the medium and cultured at 25"C for 7 days. For comparison, the strain was inoculated on a nutrient broth medium not coated with the water-soluble calcium saccharate, and the colony numbers were compared. As a result, no generation of colony was observed on the nutrient broth medium treated with the water-soluble calcium saccharate solution whereas the colony number was 16 on the untreated nutrient broth medium. 35 Example 2 10 parts of lime powder was added to 100 parts of water while stirring and 40 parts of officially prescribed glucose was added thereto and the mixture was allowed to react at room temperature for 4 hours to obtain a water-soluble calcium glucose saccharate solution. This solution was diluted with water to 10 folds to form a dipping solution. Then two samples of green shiitake mushroom (Lentinus edodes) were provided. one was dipped for 3 minutes in the dipping solution and another was not dipped. The green shiitake samples were left to stand for 28 days in the air to dry them. As a result, the shiitake mushroom sample treated with the water soluble calcium glucose saccharate solution could be dried without causing any growth of molds. On the other hand, the untreated sample showed growth of gray mold, thus deteriorating the quality. Example 3 10 parts of lime powder was added to 100 parts of water while stirring and 70 parts of maltose syrup was added thereto and the mixture was allowed to react at room temperature for 4 hours to obtain a water-soluble calcium maltose saccharate solution. 5 cc of a solution obtained by diluting this solution with water to 10 folds was added to 100 parts of fermented soybeans and the mixture was stirred. This was stored for 14 days in a refrigerator. The cell number of Bacillus subtilis was compared 36 taking untreated fermented soybeans as a blank. As a result, treated fermented soybeans had a cell number of 10 4 /g and untreated fermented soybeans had a cell number of 10 9 /g. Example 4 40 parts of beet granulated sugar, 100 parts of water and 10 parts of dolomite plaster were reacted at room temperature for 4 hours. The obtained water-soluble calcium saccharate solution was diluted with water to 20 folds and the solution was coated on a nutrient broth medium. A salmonella strain was inoculated on the medium and cultured at 25 0 C for 7 days. For comparison, the strain was inoculated on a nutrient broth medium not coated with the water-soluble calcium saccharate, and the colony numbers were compared. As a result, no generation of colony was observed on the nutrient broth medium treated with the water-soluble calcium saccharate solution whereas the colony number was 16 on the untreated nutrient broth medium. Note that the term "dolomite plaster" means powder obtained by heat decomposing dolomite CaMg (CO 3

)

2 to form oxides of CaO and MgO and then reacting them with water to produce hydroxides and contains as main components about 60% of Ca(OH) 2 and about 40% of Mg (OH)2 Example 5 At room temperature 10 parts of slaked lime for food additive was suspended in 100 parts of water and 40 parts of anhydrous glucose 37 was added to the suspension with stirring. Further, 1.0 part of glacial acetic acid was added thereto and stirred. Thereafter, the mixture was left to stand for 24 hours such that it did not contact the air. The obtained calcium glucose saccharate was pale yellow and addition of 10 g of this to 100 cc of water at pH 11.6 with stirring made the mixture milky to release Ca (OH) 2 So that the pH was increased to 12.3. This stock solution was diluted with water to obtain a 2 fold diluted solution, a 4-fold diluted solution and an 8-fold diluted solution. Komatsuna samples were treated by dipping them in respective diluted solutions for 1 minute. The treated komatsuna samples were left to stand for 120 minutes to be dried under the conditions of a temperature of 20 0 C and a humidity of 60%. The samples showed weight loss ratios of 9% for the 8-fold diluted solution, 6.3% for the 4-fold diluted solution, and 5.4% for the 2-fold diluted solution. They were suitable for eating. On the other hand, the untreated sample showed a weight loss ratio of 14% and was unsuitable for eating. Example 6 At room temperature 10 parts of slaked lime for food additive was suspended in 100 parts of water, and a mixture of 10 parts of beet granulated sugar and 30 parts of sorbitol was added to the suspension with stirring. Further, 0 .5 part of 85% phosphoric acid 38 was added thereto and stirred. Thereafter, the mixture was left to stand for 24 hours such that it did not contact the air. This solution was diluted with water to 5 to 20 folds. The dilutions were suitable for maintaining the freshness of vegetables, fruits, meats and fishes by inhibition of bacteria and carbonation. Upon production of this solution, removal of beet granulated sugar and change of the amount of sorbitol to 40 parts result in precipitation of crystals, thus failing to give rise to a uniform solution and decreasing hydrolyzability aimed at. Example 7 At room temperature 10 parts of lime was suspended in 100 parts of water, and a mixture of 35 parts of beet granulated sugar and 5 parts of corn starch was added to the suspension with stirring and the resulting mixture was heated to 80"C to dissolve the corn starch. Further, 0.5 part of 85% phosphoric acid was added thereto and stirred. Thereafter, the mixture was left to stand for 24 hours such that it did not contact the air. Upon dilution with 200 folds of water, complete hydrolysis occurred to give 13 g of calcium hydroxide. The solution was suitable as freshness maintaining agent for vegetables. The cornstarch was converted to dextrin by heating and reacted with the resultant slaked lime to form calcium dextrin. However, corn starch alone has a viscosity too high to be suitable for the purpose of the present invention and the spreadability could not 39 be improved before it was mixed with beet granulated sugar. Example 8 At room temperature 10 parts of lime was suspended in 100 parts of water, and a mixture of 10 parts of beet granulated sugar and 40 parts of xylitol was added to the suspension with stirring. Further, 5 parts of citric anhydride was added thereto, and the resulting mixture was left to stand overnight, followed by removing the precipitates to obtain a solution of calcium xylitol granulated sugar. When common salt in a concentration of physiological saline was added to it, this solution was suitable as an antimicrobial and freshness maintaining agent for fish and meat. Comparative Example 1 At room temperature 10 parts of lime was suspended in 100 parts of water, and 50 parts of xylitol was added to the suspension with stirring for reaction. However, crystals were precipitated and no solution could be obtained. The crystals were poorly soluble upon dilution with water, thus failing to cause hydrolysis. Example 9 At room temperature 10 parts of lime was suspended in 100 parts of water, and a mixture of 10 parts of beet granulated sugar and 40 parts of maltose was added to the suspension with stirring. Further, 5 parts of citric anhydride was added thereto, and the resulting mixture was left to stand overnight, followed by removing the precipitates to obtain a solution of calcium maltose granulated 40 sugar. Upon dilution of this solution with water, hydrolysis readily occurred to increase the pH of the solution. Thus, this solution was suitable for maintaining the freshness of vegetables. Comparative Example 2 At room temperature 10 parts of lime was suspended in 100 parts of water, and 50 parts of maltose was added to the suspension with stirring for reaction. However, crystals were precipitated and no solution could be obtained. Heating the crystals gave rise to a solution but it showed poor hydrolyzability and less pH increase. The crystals were poorly soluble upon dilution with water, thus failing to cause hydrolysis. Example 10 At room temperature 10 parts of lime was suspended in 100 parts of water, and a mixture of 10 parts of beet granulated sugar and 50 parts of erythritol was added to the suspension with stirring. Further, 5 parts of citric anhydride was added thereto, and the resulting mixture was left to stand overnight, followed by removing the precipitates to obtain a solution of calcium erythritol granulated sugar. Upon dilution of this solution with water, hydrolysis readily occurred to increase the pH of the solution. Thus, this solution was suitable as a preservative, and addition of alcohol gave rise to a disinfectant. Comparative Example 3 At room temperature, 10 parts of lime was suspended in 100 41 parts of water, and 50 parts of erythritol was added to the suspension with stirring for reaction. However, crystals were precipitated and no solution could be obtained. The crystals were poorly soluble upon dilution with water, thus failing to cause hydrolysis. Example 11 At room temperature, 10 parts of lime was suspended in 100 parts of water, and a mixture of 10 parts of beet granulated sugar and 50 parts of maltitol was added to the suspension with stirring. Further, 5 parts of citric anhydride was added thereto, and the resulting mixture was left to stand overnight, followed by removing the precipitates to obtain a solution of calcium maltitol granulated sugar. Upon dilution of this solution with water, hydrolysis readily occurred to increase the pH of the solution. Thus, this solution was suitable as a preservative, and addition of alcohol gave rise to a disinfectant. Comparative Example 4 At room temperature, 10 parts of lime was suspended in 100 parts of water, and 50 parts of maltitol was added to the suspension with stirring for reaction. However, crystals were precipitated and no solution could be obtained. The crystals were poorly soluble upon dilution with water, thus failing to cause hydrolysis. Example 12 At room temperature, 10 parts of lime was suspended in 100 42 parts of water, and a mixture of 10 parts of beet granulated sugar and 50 parts of fructooligosaccharide was added to the suspension with stirring. Further, 10 parts of vinegar was added thereto, and the resulting mixture was left to stand Overnight, followed by removing the precipitates to obtain a solution of calcium fructooligosaccharide granulated sugar. Upon dilution of this solution with water, hydrolysis readily occurred to increase pH. Thus, this solution was suitable as a preservative and was suitable for maintaining the freshness of meat and fish. Comparative Example 5 At room temperature, 10 parts of lime was suspended in 100 parts of water, and 50 parts of fructooligosaccharide was added to the suspension with stirring for reaction. However, the reactivity was poor and crystals were precipitated so that no solution could be obtained. The crystals were poorly soluble upon dilution with water, thus failing to cause hydrolysis. Example 13 At room temperature, 10 parts of lime was suspended in 100 parts of water, and a mixture of 10 parts of beet granulated sugar and 50 parts of galactooligosaccharide was added to the suspension with stirring. Further, 10 parts of vinegar was added thereto, and the resulting mixture was left to stand overnight, followed by removing the precipitates to obtain a solution of calcium galactooligosaccharide granulated sugar. Upon dilution of this 43 solution with water, hydrolysis readily occurred to increase pH. Thus, this solution was suitable as a preservative and was suitable for maintaining the freshness of meat and fish. Comparative Example 6 At room temperature, 10 parts of lime was suspended in 100 parts of water, and 50 parts of galactooligosaccharide was added to the suspension with stirring for reaction. However, the reactivity was poor and crystals were precipitated so that no solution could be obtained. The crystals were poorly soluble upon dilution with water, thus failing to cause hydrolysis. Example 14 At room temperature, 10 parts of lime was suspended in 100 parts of water. To this was added 40 parts of high grade white sugar with stirring. Further, 5 parts of sodium bicarbonate was added thereto. The resulting mixture was left to stand overnight, followed by removing the precipitates to obtain a solution of calcium saccharate. Upon dilution of this solution with water, hydrolysis readily occurred to increase pH. Thus, the solution was suitable for antimicrobial washing and maintenance of the freshness of vegetables, fruits and seeds. Example 15 At room temperature, 1.0 part of purified konnyaku powder was suspended in 100 parts of water. While heating the suspension at 80 C with stirring, 5.0 parts of the calcium saccharate solution 44 prepared in Example 14 was added and the mixture was left to stand. Washing eggs with the resulting solution and drying them to coat the surface of eggs exhibited antimicrobial and freshness maintaining effects. Further, at room temperature, 3.0 parts of purified konnyaku powder was suspended in 100 parts of water. While heating the suspension at 800C with stirring, 10 parts of the calcium saccharate solution prepared in Example 14 was added and the obtained mixture was cast into a mold and solidif ied. As a result, a bulb of kyonnyaku was prepared that needed no hot water treatment unlike the kyonnyaku using slaked lime. Example 16 10 parts of gum Arabic was dissolved in 40 ml of water. To this solution was added 20 cc of beet sugar calcium saccharate solution (containing 6.3% as CaO) to render the solution alkaline. The obtained viscous solution was suitable for coating fruits and eggs. Example 17 1 kg of Milky Queen was dipped for 12 hours in a solution obtained by diluting the calcium maltitol granulated sugar solution in Example 11 with water 10 folds. After removing floating paddies, the sedimented paddies were dried and sown in a paddy field. The germination day number increased by 3 days at an elapsed time temperature of 100 0 C but no germination failure occurred. The 45 number of attached bacteria cell was 3

X

1 0 14, which decreased to 2 x 1 0 13 after the treatment. The yield was quite the same as that of the blank. Example 18 After treating vegetables, fruits, dried meat, dried fish and smoked products with various calcium saccharate aqueous solutions prepared in Examples 5 to 16, respectively, forcible carbonation was performed by placing them in a 10 to 30% carbon dioxide gas stream at 1 to 50C or less. As a result, the carbonation could be achieved at a carbonation rate about 10 times as fast as that of the carbonation with carbon dioxide gas in the air. At a humidity of 85%, a change in weight for 7 days was by 3% less than that of the carbonation in the air. Therefore, the calcium saccharate aqueous solutions were suitable for long term low temperature preservation under such depository conditions as above. Note that the discoloration of BTB indicator disappeared in 48 hours and the neutralization proceeded so that as comparing with the case where it was left to stand in the air, there was a dif ference of 5 days. Example 19 Using the various calcium saccharate aqueous solutions obtained in Examples 5, 6, 8 and 10, growth inhibitory concentrations for various bacteria as shown in Table 1 were assayed. For comparison, similar assay was carried out on aqueous solution 46 of slaked lime. The results obtained are shown in Table 1. Table 1 Growth Inhibitory Concentrations of Various Water-Soluble Calcium Saccharates on Bacteria Minimum Growth Inhibitory Concentration (%) Name of Strain Slaked Ex. 5 Ex. 6 Ex. 8 Ex. 10 Lime Bacillus subtilis IFO 13722 0.03 0.03 0.02 0.02 0.10 Bacillus subtilis PC 1219 0.03 0.03 0.03 0.02 0.10 Staphlococcus aureus IFO 13276 0.05 0.06 0.05 0.03 0.15 Staphlococcus aureus JCM2 413 0.03 0.03 0.03 0.02 0.10 Escherichia coli JCM 1649 0.08 0.06 0.05 0.03 0.12 Sobnoella enteritidis ATCC 1891 0.03 0.03 0.03 0.02 0.10 Sal, typhimurium ATCC 14028 0.07 0.07 0.05 0.04 0.15 Debaryomyces hansenii 67-40A 0.03 0.03 0.03 0.02 0.10 Hansenula anomala 150-40A 0.03 0.03 0.03 0.02 0.10 Saccharomyces cerevisiae 89-25A 0.03 0.03 0.03 0.02 0.10 Torulaspora delbrueckii 254-CA 0.03 0.03 0.03 0.02 0.10 Candida tropicalis 118-40 0.07 0.07 0.05 0.04 0.15 Example 20 The ef fect of concentration of the calcium saccharate aqueous solution of Example 6 on the growth inhibition of saprogenic bacteria. The results obtained are shown in Table 2. 47 Table 2 Growth Inhibition of Saprogenic Bacteria by Concentration of Calcium Saccharate Solution Obtained in Example 6 Concentration of Calcium Saccharate Aqueous Solution of Example 6 Dilution with 80.0 40.0 20.0 10.0 5.0 0 Water (fold) Blank CaO(%) 0.08 0.16 0.31 0.62 3.1 6.3 0min 2.0X10 3 2.0X10 3 2.3x10 3 2.0 X10 3 2.0 X 10 3 2.5 X10 2.2 x10 3 ------------------------- ------------------------------------- --------- 5min 4.0x10 3 3.0X10 3 3.0X10 3 3.0X 10 4 2.0 x10 7 1.4X10 4 1.4x10 8 10min 7.0X10 3 3.7 x10 3 2.0 X10 3 7.0x10 4 1.0X10 7 8.0x10 7 0 .2 ----------- ------- --------------------------------.-------------- 0 20 min 3.0 x 10 2 5.7 X 10 3 3.0 X10 4 8.0 X 10 7 1.5 x1 8 6.6 X 10 0 0 ----------- .--------------.-------------------------------------

L

S30 min 8.0x10 2 6.4x10 3 1.0x10 6 3.5X10 7 -3.2X10 9 0 0 '4 0 2478 45 min 3.0X10 8.Ox10 8.0x10' 3.Ox10 0 0 0 . ------------ .-------------- ..--- ------ E 60 min 6.0 x102 3.0x10 4.0x10 1.3x10 0 0 0 *Number of saprogenic bacteria cells/g/10,000 cells Example 21 The antimicrobial property of the calcium saccharate aqueous solution obtained in Example 14 on soil bacteria was assayed. For comparison, blank, formalin and aqueous solution of lime were similarly assayed. The results obtained are shown in Table 3. 48 Table 3 Antimicrobial Test of Various Chemicals on Soil Bacterial (Cultivated at 36 0 C for 24 Hours) Antimicrobial Property of Calcium Saccharate Solution of Example 14 on Soil Bacteria Formalin Lime Calcium Saccharate Concentration (CaO%) O. 36% 5. 0% 0. 19 0.37 0.75 1.11 1 0 0 0 0 0 0 0 3 3 0 0 0 0 0 0 M 6 8 2 0 1 O O O 12 16 6 2 2 2 3 1 0 0 18 28 20 5 3 2 4 2 24 34 26 8 8 4 3 2 pH 7.2 7. 1 11. 9 8. 7 10. 5 10. 6 10. 7 Example 22 Change with time of viable cell number (name of bacterium: S. choleraesuis) in a 10-fold aqueous diluted solution of the calcium saccharate aqueous solution obtained in Example 5 was assayed. For comparison, the same assay was made on a 0.5% suspension of dolomite plaster. The results obtained are shown in Table 4. 49 Table 4 Change with Time of Viable Cell Number by Treatments with Dolomite Plaster and with Calcium Saccharate Aqueous Solution Time Dolomite Plaster 10-Fold Diluted Solution of (minute) (0.5% Suspension) Calcium Saccharate of Example 5 5 6.4 6. 3 Viable 10 5. 7 3. 1 Cell Ner 20 4.2 2.8 Number Oog/g) 30 3. 6 1. 2 60 2.6 0.03 Example 23 Changes with time of viable cell numbers of fresh fish and meat products treated with 5-fold aqueous diluted solution of the calcium saccharate aqueous solution obtained in Example 5 and of those untreated in a refrigerator at 5"C were assayed. The results obtained are shown in Table 5. 50 Table 5 Treatment of Fresh Fish and Butcher's Meat with Calcium Saccharate of Example 5 and Viable Cell Number 5-Fold Dilution Untreated Product Treated Product Fresh Fish, Meat Day(s) Elapsed Day(s) Elapsed 0 7 24 0 7 14 Sardine ++ ++++ +++++ + + +++ E Horse Mackerel + ++ +++++ 0 + ++ z Cuttlefish + +++ ++++ 0 0 ++ Chicken ++ +++ ++++ + ++ ++ > Pork + +++ ++++ 0 ++ +++ *: Viable cell number in a refrigerator at 5 0 C (+ indicates 50, 000 cells/g, and 0 indicates no detection.) Example 24 For various vegetables shown in Table 6, changes in appearance of those treated with calcium saccharate aqueous solution obtained in Example 5 and those untreated were observed with lapse of time. The results obtained are shown in Table 6. Table 6 Changes in Appearance with Lapse of Time of Various Vegetables by Treatment with Calcium Saccharate 51 In the case of Garland Chrysanthemum Time Weight of Weight of Dilution of Appearance Appearance Elapsed (h) Untreated (g) Treated (g) Treating Solution of Untreated of Treated 0 39. 0 55. 0 1/8 4. 3 38. 2 53. 3 - Wilting No change 7 2. 0 29. 9 49. 7 - Wilting Wilting In the case of komatsuna (a kind of Chinese cabbage (Brassica campestris)) Time Weight of Weight of Dilution of Appearance Appearance Elapsed (h) Untreated (g) Treated (g) Treating Solution of Untreated of Treated 0 95. 5 109. 0 1/8 24. 0 76. 6 79. 3 - Wilting No change 72. 0 74. 9 73. 6 - Wilting Wilting In the case of Spinach Time Weight of Weight of Dilution of Appearance Appearance Elapsed (h) Untreated (g) Treated (g) Treating Solution of Untreated of Treated 0 96. 0 85. 0 1/8 24. 0 93. 0 83. 0 - Wilting No change In the case of Bean sprouts Time Weight of Weight of Dilution of Appearance Appearance Elapsed (h) Untreated (g) Treated (g) Treating Solution of Untreated of Treated 0 100.0 100.0 1/20 - 48.0 100.0 100.0 - Sagging No sagging ______ _______ started 96.0 100.0 100. OBrowning Little browning and sagging and sagging In the case of Strawberry Time Weight of Weight of Dilution of Appearance Appearance Elapsed (h) Untreated (g) Treated (g) Treating Solution of Untreated of Treated 0 92. 0 83. 0 1/10 - 2 90. 0 80. 0 - No change No change 5 95. 7 85. 7 - Germination No change _______ ______ _______ of molds ____ 7 96. 5 87. O _ Germination Germination of molds of molds 52 Example 25 Various vegetables shown in Table 7 were measured of a change in weight with lapse of time after their 2 minutes' dipping in a 4-fold aqueous dilution of calcium saccharate aqueous solution obtained in Example 5 and preserving them at 20 0 C at a humidity of 60% in a 3% carbon dioxide gas atmosphere. Those untreated were also preserved in the same atmosphere and a .change in weight with lapse of time was measured in the same manner as above. The results obtained are shown in Table 7. Those foliage vegetables that showed a weight change ratio of above 5% underwent shrinkage of the leaves so that they had no commercial value. 53 Table 7 Rate of Change in Weight of Vegetable by 4-Fold Diluted Solution of Calcium Saccharate (Carbonation in Air) Untreated Product Treated Product Vegetable Time Elapsed (minute) Time Elapsed (minute) 0 30 60 120 240 0 30 60 120 240 Spinach 100 98 96 94 85 100 99 97 96 96 Lettuce 100 96 95 93 90 100 99 98 96 95 Quing-geng-cai 100 98 96 94 92 100 98 97 96 95 Cabbage 100 98 97 94 93 100 99 98 96 95 : Garland chrysanthemum 100 97 95 93 83 100 98 97 96 95 Chinese cabbage 100 96 95 93 92 100 99 98 96 96 + Broccoli 100 98 97 95 93 100 99 98 97 96 L4-ek- - - - Leek 100 96 95 94 92 100 99 98 96 96 Beefsteak plant 1001 96 195 93 90 100 99 98 96 96 Example 26 Various fruits shown in Table 8 were measured of a change in weight with lapse of time when preserving them at 200C at a humidity of 60% in a 3% carbon dioxide gas atmosphere after their 3 minutes' dipping in a mixed solution of a 2-fold aqueous diluted solution of calcium saccharate aqueous solution obtained in Example 9 and an aqueous solution of 3% dextrin. Those untreated were also preserved in the same atmosphere and a change in weight with lapse of time was measured in the same manner as above. 54 Preservation of the fruits in an atmosphere of 10% carbon dioxide gas after performing the above dipping treatment, carbonation occurred so that the treating efficiency could be increased by 3%. Table 8 Treatment of Fruits with Mixed Solution of 2-Fold Diluted Solution of Calcium Saccharate Solution in Example 9 + 3% Dextrin Untreated Product Treated Product Fruit Time Elapsed Time Elapsed 0 120 min 1 day 3 days 7 days 0 120 min 1 day 3 days 7 days Strawberry 100 98 96 93 putre 100 98 97 96 95 ______ ~faction ___ ___ ___ __ Tomato 100 99 98 96 95 100 99 98 97 97 L Andes Melon 100 99 99 97 95 100 99 98 97 97 Cucumber 100 99 98 96 95 100 99 98 97 97 Eggplant 100 100 99 97 96 100 100 99 98 98 Orange 100 99 99 97 95 100 99 98 97 97 0 Hassaku orange 100 99 99 97 95 100 99 98 97 97 4-, Banana 100 100 99 97 96 100 100 99 98 98 Apple 100 99 98 96 95 100 99 98 97 97 Tangerine orange 100 99 99 97 95 100 99 98 98 98 Example 27 various flowers shown in Table 9 with a flowering ratio of 50% were dipped in a 10-fold aqueous diluted solution of the calcium saccharate obtained in Example 6 and a change with lapse of time 55 of flowering ratio in an atmosphere at 10 C and a humidity 60%. The flowers not treated with the calcium saccharate aqueous solution were measured of a change with lapse of time of flowering ratio in the same manner as above. The results obtained are shown in Table 9. For improvement, 30 parts by weight of an aqueous 50% urea solution was added. As a result, the flowering ratio was improved by 3%. Table 9 Treatment of Flowers with 10-Fold Diluted Solution of Calcium Saccharate of Example 6 Untreated Product Treated Product Flower Day(s) Elapsed Day(s) Elapsed 0 3 7 14 24 0 3 7 14 24 Rape blossoms 50 85 100 50 20 50 73 83 100 35 Purple radish 50 88 95 100 25 50 73 83 100 40 o White chrysanthemum 50 57 78 100 25 50 53 67 100 45 Carnation 50 50 55 88 60 50 53 67 100 55 C Eastern lily 50 50 70 95 40 50 53 77 90 80 - Moth orchid (Phalaenopsis) 50 57 78 100 25 50 53 67 100 70 Denfare 50 53 60 100 60 50 53 60 100 80 *Data traced in terms of flowering ratio, with 100 indicating full bloom and smaller values showing that flowers fell. 56 Example 28 Komatsuna and spinach having each an average leaf length of 25 cm were dipped for 3 minutes in a calcium saccharate aqueous solution obtained in Example 5 (stock solution) and a 4-fold aqueous diluted solution thereof. Then, the samples were measured of drooping amounts with lapse of time according to a cantilever method by horizontally fixing the specimen and measuring drooping amounts in an atmosphere of 20 0 C and a humidity of 60% with setting the initial drooping amount to 0. This method allows exact quantitative determination of the phenomenon of "wilting" that has been difficult to determine by measurement of weight depending on the variety. Further, those samples not treated with the calcium saccharate aqueous solution were measured of drooping amounts in the same manner as above. The results obtained are shown in Table 10. 57 Table 10 Drooping Tests on Komatsuna and Spinach Treated with Calcium Saccharate Solution of Example 5 Treating Solution Untreated Stock Solution 4-Fold Diluted Solution Time Elapsed (minute) 0 30 60 120 0 30 60 120 0 30 60 120 Drooping Komatsuna 0 35 40 47 0 20 22 22 0 21 22 22 Amount (mm) Spinach 0 35 64 86 0 30 35 35 0 27 30 34 Example 29 To 100 parts of rice was added 1.0 cc, 0.5 cc, or 0.25 cc of 20-fold aqueous diluted solution of calcium saccharate aqueous solution obtained in Example 6, followed by sufficiently mixing. The mixture was left to stand in the air at 20 0 C for 7 days to cause putrefaction and colony number of saprogenic bacteria was counted. For comparison, samples to which none, 0.1 part, 0.05 part or 0.001 part of phenol was added were also subjected to putrefaction in the same manner as described above and the colony number of saprogenic bacteria was counted. The results obtained are shown in Table 11. 58 Table 11 Addition Colony Amount Number Calcium 1.0 cc 0 saccharate 0.5 cc 0 aqueous diluted solution 0.25 cc 5 No addition - 8 0.1 part 0 Phenol 0.05 part 0 0.001 part 3 Example 30 The root of a whole rapeseed plant having a weight of 70 to 75 g was washed with water and placed in 300 cc of 17-fold aqueous diluted solution of the calcium saccharate aqueous solution obtained in Example 5, or for comparison, 300 cc of city water, 300 cc of 5% saline, or 300 cc of a saturated slaked lime solution (0.42 g as Ca(OH) 2 ) for 7 days. Then, the amount of water absorbed was observed. The amount of water absorbed was 16 cc for the aqueous diluted solution of the calcium saccharate aqueous solution, 125 cc for city water, 65 cc for 5% saline, and 22 cc for saturated slaked lime solution. The aqueous diluted solution of the calcium saccharate aqueous solution of the present invention showed an extremely low amount of water absorbed, thus showing complete growth inhibition. 59 Example 31 On leaf surface of white chrysanthemum with a pinch ratio of 50% was sprayed a 10-f old aqueous dilution of the calcium saccharate aqueous solution obtained in Example 5 and another white chrysanthemum was untreated for comparison. The number of axillary buds was observed. After 14 days, the untreated white chrysanthemum had an axillary bud number of 45% while the treated white chrysanthemum had an axillary bud number of 13%, which means about 3 times sucker inhibitory effect. After 28 days, the treated white chrysanthemum had an axillary bud number of 67%. 60

Claims

1. An antimicrobial agent comprising a water-soluble calcium saccharate obtained by reacting at least one member selected from the group consisting of saccharides with calcium oxide or hydroxide, or magnesium oxide or hydroxide in the copresence of calcium, in the presence of water.

2. The antimicrobial agent according to claim 1, further comprising at least one member selected from the group consisting of an osmotic pressure adjusting agent, a pH adjusting agent, a surfactant, and a spreading agent.

3. A method for maintaining freshness of food, seed or flower comprising using an aqueous solution of a water-soluble calcium saccharate obtained by reacting at least one member selected from the group consisting of saccharides with calcium oxide or hydroxide, or magnesium oxide or hydroxide in the copresence of calcium, in the presence of water.

4. A method for maintaining freshness of food, seed or flower comprising treating food, seed or flower with an aqueous solution of a water-soluble calcium saccharate obtained by reacting at least one member selected from the group consisting of saccharides with calcium oxide or hydroxide, or magnesium oxide or hydroxide in the copresence of calcium, in the presence of water, and then carbonating the calcium saccharate to form a calcium 61 carbonate/saccharide complex film on the surface of food, seed or flower.

5. A coagulating agent for food, comprising a water-soluble calcium saccharate obtained by reacting at least one member selected from the group consisting of saccharides with calcium oxide or hydroxide, or magnesium oxide or hydroxide in the copresence of calcium, in the presence of water.

6. A soil disinfectant comprising a water-soluble calcium saccharate obtained by reacting at least one member selected from the group consisting of saccharides with calcium oxide or hydroxide, or magnesium oxide or hydroxide in the copresence of calcium, in the presence of water.

7. A growth regulator for vegetation, comprising a water- soluble calcium saccharate obtained by reacting at least one member selected from the group consisting of saccharides with calcium oxide or hydroxide, or magnesium oxide or hydroxide in the copresence of calcium, in the presence of water. 62