GB2045596A - Antimicrobial agent - Google Patents

Abstract

Ortho-methoxycinnamaldehyde is used to protect industrial products from the action of microorganisms. The ortho-methoxycinnamaldehyde may be extracted from cassia powder or synthesised. It has a low toxicity and may be used to preserve foodstuffs e.g. meat, fish, fruit, vegetables and dairy products. It may be used also to preserve paint, leather, paper, adhesives, plastics and other materials subject to deterioration of microorganisms.

Description

SPECIFICATION Antimicrobial agent The present invention relates to a method of protecting an industrial product from the action of microorganisms growing on and/or in the product and thus causing its deterioration.

The term "industrial product" herein means industrial raw materials, materials or substances utilized as products which are easily denatured by the action of microorganisms including paints, leathers, pigments, fibers, papers, construction materials, cosmetics, petroleum, adhesives for metals (including pastes), plastics and their products, materials for use in electronic instruments and parts, food products for human consumption, agricultural products, feeds for domestic animals and industrial matters of broader meaning such as industrial waste water.

Hitherto, several chemical compounds, for instance sorbic acid, nitrofuran derivatives, esters of p-oxybenzoic acid and particularly antibiotics such as tetracycline have been proposed for use in preservatives for human and animal foods, and for example pentachlorophenol for use in paints. Some of these have actually been employed in practice.

However, no satisfactory preservatives have been found which are both effective and safe for humans and animals. In particular, the regulations governing the use of preservatives, except in food products, are not so strict as in the case of pharmaceuticals. Accordingly, the use of toxic preservatives would harm the environment.

Antibiotics such as sorbic acid, dehydroacetic acid, salicylic acid and nitrofurazone have been put to use to protect foods for human or animal consumption from the action of microorganisms. However, these are not necessarily satisfactory in some instances because of their toxicity and in others because they are not sufficiently effective as antiseptics. Alternative techniques for preserving food products, such as utilization of cold-chain and of radiation, have been tried.

However, the use of chemical antiseptic preservatives is considered as the most advantageous in practice.

The specific properties required for compounds to protect substances from the action of microorganisms are a high preservative activity over a broad range of industrial products and a zero or extremely low toxicity to humans and animals. Bearing this in mind, it has now been discovered that o-methoxycinnamaldehyde, one of the components of cassia powder which is a crude drug used hitherto as a peptic and applied in China as an antifebriie and an analgesic, exhibits marked anti-microbial activity against microorganisms which denature industrial products and also that o-methoxycinnamaldehyde has a very low toxicity to animals.

Accordingly, the present invention provides an industrial product (as hereinbefore defined) protected from the action of microorganisms by the incorporation therein or application therto of ortho-methoxycinnamaldehyde.

In the description which follows, reference will be made to the accompanying drawings in which: Figure 1 is an infrared absorption spectrum of o-methoxycinnamaldehyde extracted from cassia powder, and Figure 2 is an infrared absorption spectrum of o-methoxycinnamaldehyde obtained by synthesis.

It is possible to confirm that the active ingredient of the present invention, o-methoxycinnam aldehyde, is a component of cassia powder by the following procedure: An extract is prepared from pulverized cassia powder using a conventional solvent and the thus-obtained crude extract is passed through a column packed with an adsorbent such as silica gel and active alumina or subjected to thin layer chromatography on a plate made of an adsorbent such as mentioned above or treated with a combination of the above-mentioned column chromatography and thin layer chromatography, and the adsorbed substance is eluated with a solvent such as hexane, benzene, chloroform and methanol. The thus obtained solution is subjected to distillation under reduced pressure to evaporate the solvent.The distillation-residue, obtained as a syruppy substance is preferably subjected to the repeated treatment described above and the syruppy product obtained at last is recrystallized from a solvent to the purified substance. The thus obtained substance showed its melting point of 45 to 46"C and its boiling point of "C. The results of its elementary analysis, the infrared spectroscopy and its melting point determination were compared with those of the synthesized product of o-methoxycinnam aldehyde by the following procedures and both showed a fairly good coincidence. The identification of the extracted substance with the synthesized product was finally carried out by the co-melting without any melting point depression.

Synthesis of o-methoxycinnamaldehyde: Acetaldehyde is made to react with o-methoxybenzaldehyde and the reaction product is distilled under reduced pressure to collect the fraction distilling at 100 to 1 30 C at 3 mm Hg.

The fraction is recrystallized from methanol. The synthesized o-methoxycinnamaldehyde was analytically compared with the present substance isolated from cinnamon powder by the extraction and purification procedure, revealing that the both substances were identical to each other in the elementary analytical values, the infrared absorption spectra and the melting points and that no depression of melting point was observed when the both substances were subjected to a mixed examination.

The above-mentioned test results verify that the component of the cassia powder obtained by the above-mentioned extraction and purification is o-methoxycinnamaldehyde The active ingredient of the preservative of the present invention, that is, o-methoxycinnamaldehyde has the following physical properties and physiological properties: (1) Physical properties: Melting point 45 to 46"C Boiling point 295"C/760mmHg 160 to 161"C/12mmHg Solubility soluble in methanol, ethanol, acetone, benzene and chloroform.

insoluble in water (2) Mammalian acute and sub-acute toxicities: Ortho-methoxycinnamaldehyde obtained by synthesis was dispersed in a 1 : 2 mixture of Tween 80 (made by Atlas Co.) and an aqueous saline solution, and the suspension thus prepared was administered per os and per cutaneous,respectively to commercial female ICR-JCL mice (average body weight of 22 + 1 g) and the mortality of the mice was observed after one week of administration. The value of LD50 was obtained from the mortality and by the method of Litchfield-Wilcoxon and shown in Table 1 together with the result of the same test using the product extracted from the cassia powder.

Table 1: Acute toxicity of o-methocycinnamaldehyde Specimen Route of Number of LD50 (mg/kg) administration mice administered Crude extract from per os 1 0 12,000 cassia powder Synthesized o-methoxy- per os 10 4,430 cinnamaldehyde Synthesized o-methoxy- per cinnamal- cutaneous 10 8,670 dehyde From these results, it is confirmed that o-methoxycinnamaldehyde is fairly safe even when administered in a large dose. In addition, on the autopsy carried out after one week of the administration, no abnormal findings was observed from outside and in internal organs. In addition, no specific toxicological symptoms was observed.

Furthermore, on the sub-acute toxicity test carried out by daily administering, respectively, 100 mg/kg per os or 250 mg/kg per cutaneous of the product for consecutive 3 months, no death nor any abnormal findings were observed.

(3) Anti-microbial spectrum: The anti-microbial spectrum was prepared by using the synthesized o-methoxycinnamaldehyde against the representative microorganisms shown in Table 2 by the under-mentioned procedures, the resulted spectrum being shown in Table 2.

Preparation of the preservative: The synthesized o-methoxycinnamaldehyde was minutely pulverized and dispersed in an aqueous 1 % carboxymethylcellulose solution to be the original liquid which was mixed to the culture medium.

Determination of anti-microbial activity: Into a sterilized culture medium mixed with a heart infusion solution, the above-mentioned original liquid was admixed to be a predetermined concentration of o-methoxycinnamaldehyde and culture plates were prepared. Each microorganism representative of those growing on and/or in industrial matters and denature them was cultered for a night in a slant culture medium at a temperature of 37"C and a platinum loop-ful amount of the culture was dispersed into 9ml of an aqueous saline solution. The one platinum loop-ful amount of the dispersion was painted on the above-mentioned culture plate and incubated for 48 hours at a temperature of 37"C to observe the state of the growth of the inoculated microorganism.

The minimum concentration of the substance in inhibiting the growth of the microorganism tested as above (abbreviated as Minimum Inhibiting Concentration, MIC) was obtained by treating the observed results with the ordinary method on each microorganism, the values of MIC being shown in Table 2. In addition, for comparison, the result of the same test using potassium sorbate as a preservative for use in food products is also shown in Table 2.

Table 2: Anti-microbial Spectrum (MIC vs. Microbial species) unit: microgram/ml Minimum Inhibiting Concentration (MIC) Microorganism o-methoxycinnamaldehyde Potassium Sorbate" Bacillus subtilis 100 1,000 Bacillus cereus 200 larger than 2,000 Bacillus mycoides 200 larger than 2,000 Proteus vulgaris 300 larger than 2,000 Clostridium perfringens** 300 larger than 2,000 Alcaligenes faecalis 50 not tested Rhizopus nigricans 100 as above Cladosporium resinae 50 as above Penicillium citrinum 50 as above Note: *, calculated as sorbic acid.

anaerobically cultured in a culture medium with brain and heart infusion solution at a temperature of 37"C, and observed after 2 days of inoculation.

As is seen in Table 2, the substance of the present invention shows a broad anti-microbial spectrum and accordingly, it will be understood that o-methoxycinnamaldehyde is possibly applied on many kinds of matters advantageously as a preservative, and particularly that the present substance exhibits an extremely excellent anti-microbial activity as compared to sorbic acid which is now broadly used in the world as a safe preservative derived from natural products for food products.

In this connection, since sorbic acid has a demerit in which it ionizes in foods of pH of more than 7 and its anti-microbial activity is reduced to one third-one fifth of the original activity, the antiseptic effectiveness of sorbic acid is very much impaired in fish pastes such as KAMABOKO for the production of which a treatment in alkaline region is necessary.

On the contrary, since o-methoxycinnamaldehyde for use in the present invention has no ionizable functional group in such an environment, it shows the stabilized antiseptic effectiveness irrespective of the value of pH of the applied food products and accordingly, it has an advantage of expecting a broad range of utilization.

Consequently, the preservative of the present invention containing o-methoxycinnamaldehyde as an active ingredient is particularly suitable as the antiseptic for food products and applicable not only for the primary processed food products and the secondary processed food products but also for the raw food materials for the above-mentioned processed food products, and freely applicable effectively to putrefactive food products, for instance, alcoholic beverages, soyasauce, bean jam, preserved foods with soya-bean sauce, noodles, dairy products such as butter and cheeses, margarines, fish-meat products and animal-meat products.

Further, the preservative of the present invention is the most suitable for the preservation of feeds for many kinds of domestic animal such as cattle, swine, minks, dogs and cats, experimental animals such as rats, mice and guinea pigs, domestic fowl, cultivated fishes such as eels and yellowtails and silkworms.

In addition, the preservative of the present inventions is preferably suitable not only for the preservation of industrial matters such as paints, leathers, pigments, fibers, plastics, papers, materials for construction, cosmetics, pastes for adhesion, petroleum products, adhesives for metals, organic parts materials in electronic instruments but also for the improvement of the preservative property of agricuLtural products such as fruits, vegetables and cereals when applied on their surface.

The o-methoxycinnamaldehyde used in the invention is possibly applicable as the state of the crystalline po.wder itself, of the solution dissolved in a solvent such as ethanol and propylene glycol or of the suspension dispersed in an aqueous solution of a surfactant such as carboxymethylceltulose, Tween 80 and fatty acid esters of sucrose, or else, according to the kinds and properties of the objectives, it is possibly admixed uniformly with them after diluting with a substance such as lactose, glucose, common salt and.polyphosphates. In addition, in cases of applying o-methoxycinnamaldehyde to an aqueous substance, a dissolution-aid agent, for instance, cyclodextrin may be used together for the improvement of dissolution of the present substance.

Accordingly, the preservative of the present invention is applicable by any of the following procedures corresponding to the kinds af the object matters: mixing, immersion, spraying, surface-painting, injection and dissolution.

The amount of o-methoxycinnamaldehyde applied is usually 0.001 to 0.5% by weight of food product, preferably 0.01 to 0.5% by weight, 0.001 to 1% by weight of--animal feed, preferably 0.01 to 1% OXD by weight. In cases for other organic matters, it is usuallymore than 0.001% by weight, preferably 0.01 to 5% by weight, however, it is preferably applied at 0.1 to 50 g/m2 in cases of surface painting.

On the other hand, since o-methoxycinnamaldehyde can be applied as a preservative of industrial matters in broad range, .it should be understood that the present substance may be applied without limitation of the -amounts above-mentioned according to the kinds of the objects to be preserved.

The following are the concrete explanation of the present invention referring to the non limitative examples: EXAMPLE 1: The present example illustrates a method of preparation of the active ingredient of the .preservative of the present invention, i.e., o-methoxycinnamaldehyde from cassia powder.

Pulverized -cassia bark (of Pharmacopeia Japonica) was extracted with chloroform for 20 minutes at the room temperature, and the extracted solution was condensed to obtain a crude extract. After having the extract adsorbed on a column of silica gel, the adsorbed substance was first etuated with hexane, then -a a: 1 mixture of benzene and chloroform, chloroform and methanol in order. The fraction eluated with the mixture of benzene and chloroform was coollected. After -adsorbing the collected fraction on column packed with active alumina (Active alumina 90, activity at neutral of 1, made by Wako Pure Chemicals Co.), the column was eluated with the above-mentioned solvents in the above-mentioned order and the fraction eluated by chloroform was collected.

This fraction was further subjected to thin-layer chromatography using Kiesel gel G (made by Merck 8 Co.) of 0.25 mm in thickness and using benzene as a developing solvent. The portion of the thin-layer at Rf of 0.4 was scraped, extracted with chloroform and after evaporating chloroform a syr.uppy substance light yellow in colour was obtained. After repeating the thin layer chromatographical treatment of 2 times, the finally obtained syrup was solidified by cooling and recrystallized from a small amount of methanol to obtain a crystalline substance of melting point of-45.8'C, showing an elementary composition of carbon of 74.25% and hydrogen af 6.20% and the balance sf oxygen. An infrared absorption spectrum of this crystal is shown in Fig. 1.

In the next place, for the identification of the above-mentioned crystal presumed to be o methoxycinnamaldehyde, o-methoxycinnamaldehyde was synthesized by the under-mentioned procedures and examined its physical property: Synthesis of o-methoxycinnamaldehyde: Ten grams of sodium hydroxide and 50 g of o-methoxybenzaldehyde were dissolved into a mixture of 300 ml of ethanol and 400 ml of water, and 40 g of acetaldehyde were dropwise admixed with the thus obtained solution at a temperature of 0 to 5"C.

After completion of the addition of acetaldehyde, the mixture was agitated for about 2 hours at the above-mentioned temperature, and after adding 400 ml of water to the reaction mixture, it was extracted with benzene. The benzene layer was separated, washed with water and dried, and then benzene was distilled off to leave a syruppy substance reddish brown in colour. After subjecting the syrupy substance to distillation under reduced pressure and collecting the fraction distilling at 1 00 to 1 :30 C at 3mm Hg, the fraction was solidified by cooling and recrystallized from a small amount of methanol to obtain 36.9 g of a colourless crystalline substance melting at 45.5'Cand showing an elementary composition of carbon of 74.14%, hydrogen of 6.19% and the balance of oxygen. The infrared absorption spectrum of the thus obtained product is shown in Fig. 2. On the comparison of the melting point, the elementary composition and the infrared absorption spectrum of the extracted product and the synthesized product, a quite satisfactory coincidence could be observed between two products.Further, a co-melting test of the two products showed no melting point-depression. These facts support the identification of the extracted product as o-methoxycinnamaldehyde.

EXAMPLE 2: The present example shows the preserving effect of the substance of the invention on beanjam.

After boiling a mixture comprising 1.5 kg of a raw bean-jam, 1 kg of sucrose and 0.5 g of powdery o-methoxycinnamaldehyde by external heating for 30 minutes, the mixture was divided into 250 g-portions and the portions were cooled in their own dishes. The dishes with the specimen were preserved in a thermostat kept at a temperature of 37"C and the number of dishes in which putrefaction took place was observed daily for 9 days. The results of observation are shown in Table 3.

Table 3: Number of dishes in which putrefaction took place Days after Plot 3 5 7 9 Preservative not added "2/10 10/10 2,000ppm of sorbic acid was added 0/10 3/10 10/10 2,000ppm of o-methoxycinnamaldehyde was added 0/10 0/10 0/10 0/10 Note: "2/10 shows that putrefaction was observed in 2 dishes among 10 dishes.

EXAMPLE 3: The present example shows the preservative effectiveness of the present substance on fishmeat sausages.

To the total amount of a fish-meat paste comprising 30% of swordfish-meat, 50% of whalemeat and 20% of codfish-meat, 10% of starch, 10% of lard, 3% of common salt and 14% of water were admixed, and o-methoxycinnamaldehyde was added to the total amount of the above-mentioned mixture at a concentration of 400 ppm.

As a control, potassium sorbate was added to another mixture with the same composition as above, at a concentration of 2,000 ppm.

After mixing the respective mixtures well, they were respectively packed into film casings made of a film of polyvinylidene chloride. After sealing and sterilizing the casings at a temperature of 90"C for 60 minutes, the casings were kept in a thermostat at a temperature of 35"C to observe the states of the casings from outside to find the number of casings showing expansion due to the putrefaction of the content. The results of observation until 28 days are shown in Table 4.

Table 4: Number of casings showing expansion Days of keeping Plot 7 14 21 28 Preservative not added *20/20 - - Added with sorbic acid 1/20 8/20 20/20 Added with o-methoxycinnamaldehyde 0/20 0/20 2/20 4/20 Note: *20/20 means 20 casing showed expansion after preservation for 7 days among total of 20 casings.

EXAMPLE 4: The present example shows the preserving effectiveness of the substance of the present invention on KAMABOKO (a kind of fish-meat paste sausages).

To a fish meat paste comprising 50% of horse-mackerel-meat and 50% of codfish-meat, 8% of starch, 3% of common salt, 3% of sucrose and 20% of water were admixed. Qrthomethoxycinnamaldehyde and sorbic acid were admixed respectively to the above-mentioned fishmeat mixture at a respective concentration of 200 and 2,000 ppm, and the total mixture was packed into each 20 casings made of polyvinylidene chloride film. After sealing and sterilizing the casings at a temperature of 90"C for 60 minutes, they were placed in a thermostat of a temperature of 35"C for observation of the change of the state of the casings from outside, especially the expansion of the casing due to the content's putrefaction.

The results of observation, i.e., the number of casings shown expansion due to the putrefaction af their content are shown in Table 5.

Table 5: Number of casings showing putrefaction after days of observation.

Days of preservation Plot 7 14 21 Preservative not added "2/20 20/20 2,000 ppm of sorbic acid was added 0/20 5/20 18/20 200 ppm of o-methoxycinnamaldehyde was added 0/20 0/20 1/20 Note: "2/20 means that two casings showed putrefaction after 7 days of preservation among twenty casings.

EXAMPLE 5: The present example shows the preservative effectiveness of the preservative of the present invention on painted surface.

A standard paint specimen was prepared according to the indication of the method of determination of anti-molding property of paints of JIS (Japanese Industrial Standard), and after adding o-methoxycinnamaldehyde and sodium pentachlorophenate respectively to the specimens, they were painted on small flat plates.

"The recipe of the standard paint specimen is: Pigment 40 parts (by weight) An emulsifying agent 0.1 to 0.5 part Water 1 to 20 parts Copolymer of vinyl acetate and styrene 40 parts, and Viscosity raising agent 3 to 8 parts.

After leaving the painted plates to stand under the predetermined conditions for a predetermined period, the degree of mold proliferation was observed and classified into the five classes of -, +, +, + + and + + + . The results of the classification are shown in Table 6 together with the indication according to the method of indication of anti-molding property according to JIS.

Table 6: Degree of mold proliferation and effectiveness of its prevention Concent- Degree of Anti-mold ration of prolife- property Plot preserva ration according tive (%) to JIS Preservative not added - + + + 1 0.1 + + + 1 Sodium Penta- 0.3 + 2 chlorophenate 0.7 + 2 1.0 - 3 0.1 +++ 1 O-methoxy- 0.3 - 3 cinnamalde- 0.3 - 3 hyde added 0.7 - 3 1.0 - 3 EXAMPLE 6: The present example shows the preservative effectiveness of the preservative of the present invention on citrus fruits.

Ten fruits of Fortunella japonica were immersed into an ethanolic solution containing 1 % by weight of o-methoxycinnamaldehyde to have an amount of the chemical on the fruit surface of more than 1 g/m2 and the fruits were taken out just after the immersion and dried. The fungal spores collected from the rotten fruit of Fortunella japonica were inoculated on the thus treated fruits via a tampon containing the spores tapped on the treated fruits. The inoculated fruits were inserted into a tall-walled dish containing sawdust wetted with water at the bottom and the dish was covered with a wet sheet of filter paper and left to stand for 5 days at a temperature of 25"C. The occurence of any disease was not observed on the treated fruits.In the case where the fruits not treated as above were processed in the similar manner, the occurrence of mold was observed on 5 fruits among 10 fruits.

EXAMPLE 7: The present example show the inhibition of mold occurrence on plastic materials of electric parts of o-methoxycinnamaldehyde.

An electric wiring plate was put into a bag made of polyvinylidene chloride film and had its internal surface of the bag sprayed with a 3% by weight of acetonic solution of omethoxycinnamaldehyde to have a deposition of the chemical at 1 g/m2 and after making the atmosphere of the bag to be 90% (RH) of humidity and sealing the bag, it was left to stand for 3 months at a temperature of 30"C. No hairy mold was observed in the plate. However, on the plate put into the same bag of polyvinylidene chloride but not sprayed its inner surface with an acetonic solution of the chemical, a development of a hairy mold was observed after 3 months of preservation at 30"C.

EXAMPLE 8: The present example shows the preserving effectiveness of the substance of the present invention on the animal feed.

A paste of pet food prepared by chopping and grinding 1 Kg of beef, 1 Kg of liver of cattle and 1 Kg of bone of cattle respectively salted for one to two days with 30 g of common salt, 0.2 g of sodium nitrite and 0.3 g of potassium bromate, adding o-methoxycinnamaldehyde and sorbic acid, respectively and further adding 0.5 Kg of starch, 0.5 Kg of soybean protein and one liter of water and then mixing all the components well, was packed in casings made of polyvinylidene chloride film. After sealing the casings, they were sterilized at a temperature of 85 to 90"C for 60 minutes to prepare 20 pieces of pet food of sausage type, respectively containing o-methoxycinnamaldehyde and sorbic acid. These pet foods were kept at a temperature of 30"C for observation of their state of expansion if any.The results of observation are shown in Table 7.

Table 7: Preserving effectiveness appeared on pet food Plot Days for preservation 7 14 21 28 Preservative not added *20/20 - - Sorbic acid added 16/20 20/20 - O-methoxycinnamaldehyde added 0/20 0/20 1/20 6/20 Note: "20/20 means that 20 casings showed expansion due to putrefaction of the content among 20 casings after 7 days.

EXAMPLE 9: The present example shows the preservative effectiveness on Silkworm' feed.

To dried powder of mulberry leaves, an aqueous 1 % solution of carboxymethylcellose was added to wet the powder, and after the addition of the powder of o-methoxycinnamaldehyde to the wet powder to make the concentration of the chemical to a predetermined value, the wet powder was extruded to be granules. After drying the granules to the water content of 30 to 60%, the granules were subdivided and packed into small bags made of polyvinylidene chloride film, and then preserved in a thermostat at a temperature of 37"C. The number of putrid bags was enumarated every week. The results are shown in Table 8.

Table 8: Preserving effectiveness of Silkworm's feed Days of preservation Plot 7 14 21 28 Preservative not added 0/10 "2/10 3/10 6/10 200 ppm of o-methoxycinnamaldehyde was 0/10 0/10 0/10 0/10 added Note: "2/1 0 means that two bags showed the putrefaction of their content among the total 10 bags after 14 days.

EXAMPLE 10: The present example shows the preserving effectiveness on feeds for animals.

The feed for forced alimentation composed of 50% of milo, 20% of corn, 10% of soybean cake, 5% of fish meal, 10% of alphalpha, 3% of calcium phosphate and 2% of vitamins and others was mixed with 0.2% by weight of o-methoxycinnamaldehyde, and the mixture and the feed itself were respectively stored at a temperature of 30"C and at a relative humidity of 80% for 5 weeks. The feed without addition of o-methoxycinnamaldehyde showed deterioration, however, the feed admixed with o-methoxycinnamaldehyde did not show any deterioration.

EXAMPLE 11: The present example shows the preservative effectiveness on feed for fishes.

The raw material for breeding fishes composed of 50% of internal organs of fishes, 10% of wheat hull, 20% of rice bran, 10% of defatted soybean and 10% of gluten meal was mixed well and dried at a temperature of 1 30 to 150"C and then pulverized. Another batch of the raw material of the same composition was treated same as before, however, at first 0.8% by weight of o-methoxycinnamaldehyde was added before mixing. The abovementioned two batches of the feed for fish-breeding were stored at a room temperature of 30"C and at a relative humidity of 85% for 30 days. The feed without adding o-methoxycinnamaldehyde gave out a bad smell, however, the feed added with the substance of the present invention did not give out such a bad smell.

Claims (11)

1. An industrial product (as herein before defined) protected from the action of microorganisms by the incorporation therein or application thereto of ortho-methoxycinnamaldehyde.

2. A product according to claim 1 wherein the ortho-methoxycinnamaldehyde has been incorporated in or applied to the industrial product in the form of a solution.

3. A product according to claim 2 wherein the solution contains a solubilizer for the orthomethoxycinnamaldehyde.

4. A product according to claim 3, wherein said solubilizer is cyclodextrin.

5. A product according to claim 1 wherein the ortho-methoxycinnamaldehyde has been incorporated in or applied to the industrial product in the form of a suspension.

6. A product according to any one of the preceding claims wherein the ortho-methoxycinnamaldehyde has been incorporated in or applied to the industrial product together with a diluent.

7. A product according to claim 6, wherein said diluent is lactose, glucose, polyphosphate or common salt.

8. A product according to any one of the preceding claims which is a food for human consumption.

9. A product according to any one of claims 1 to 7 which is an animal foodstuff.

10. A product according to claim 1 substantially as hereinbefore described with reference to any one of Examples 2 to 11.

11. Ortho-methoxycinnamaldehyde for use in protecting an industrial product (as hereinbefore defined) from the action of microorganisms.