A kind of universal fruit coating antistaling agent based on lysozyme and using method thereof
Technical field
The present invention relates to a kind of fruit antistaling agent, be specifically related to a kind of universal fruit coating antistaling agent based on lysozyme and using method thereof, it is adaptable to expand scope of restraining fungi, strengthen bacteriostasis.
Background technology
Along with living standard improves, the fruit demand of different regions Various Seasonal output is gradually increased by people, and fresh fruit easily naturally rots after harvesting, its storage, transport and practicality are brought impact, have a strong impact on the economic benefit of fruit, therefore, it is suppressed that fruit aerobic respiration, slow down its moisture loss and metabolism, the freshness date of proper extension fruit, reduces rotting rate and has great importance.
Existing fruit freshness preserving technology mainly has: physical fresh-keeping and fresh chemically.Physical fresh-keeping mainly includes that deepfreeze is fresh-keeping, controlled atmosphere, pressure-reducing fresh-keeping, radiation preservation etc., this technology energy-output ratio is big, relatively costly.Fresh chemically includes fresh-keeping to fruit of the chemical preservatives such as deoxidation acetic acid, sulfur dioxide, potassium sorbate, but a lot of chemical preservative of life-time service easily affects safety and the wholesomeness of fruit.Additionally, also include using preservative film to realize suppressing the breathing of fruit to reach preservation, but owing to preservative film release period is shorter, space is excessive causes that fruit moisture evaporation is too fast and dehydration is serious, it is difficult in order to be effective, so fresh keeping time is extremely short.
Lysozyme is the protein of a kind of safety non-toxic, has good bacteriolysis, and it can decompose many gram positive bacterias such as micrococcus lysodeikticus, bacillus megaterium, sarcina flava, is a kind of safe and reliable and of good performance antibacterial.Lysozyme itself is nontoxic, harmless, alternative such as chemical preservatives such as benzoic acid and sodium benzoates, and the illegal additive such as Borax etc. that food often adds in recent years, it is possible to effectively extend effective period of food quality.The bacillus subtilis of gram positive bacteria, micrococcus radiodurans are had powerful decomposition by lysozyme, but the antimicrobial limited use to gram negative bacteria, simple use lysozyme cannot play comprehensive antiseptic effect as antistaling agent, and research proves that lysozyme composite antistaling agent is greatly improved its antiseptic effect.
Chinese patent: Authorization Notice No. is CN103450719A, the patent of invention that authorized announcement date is on October 9th, 2013 discloses a kind of composite biological film-coating agent and for blueberry preserved method, it is 0.5% 5% water-soluble chitosans, 0.01% 0.3% citric acids, 0.005% 0.01% nisins, 0.005% 0.01% lysozyme, 0.05% 0.2% propylene glycol, 0.01% 0.1% nanometers of polyoxy SiClxs and 0.01% 0.1% glycerol that this composite biological film-coating agent contains mass ratio, and all the other are water.Although this invention is remarkably improved the hot strength of chitosan complex film, elongation at break and tearing strength, prevent to some extent the physical injury of fruit and vegerable, but still there is following defect:
1, this invention is selected lysozyme, nisin are relatively strong to the fungistatic effect of gram positive bacteria, but the fungistatic effect of gram positive bacteria is more weak, and therefore its scope of restraining fungi is narrower;
2, lysozyme in this invention, nisin content relatively low, bacteriostasis is more weak, and the content of water-soluble chitosan is higher, it is easy to cause that composite biological film-coating agent not easily dries, and brings some inconvenience to practical operation application.
Summary of the invention
It is an object of the invention to overcome that the middle scope of restraining fungi existed in prior art is narrower, bacteriostasis is more weak, not easily dry problem, it is provided that a kind of scope of restraining fungi is wider, bacteriostasis is relatively strong, the easily dry universal fruit coating antistaling agent based on lysozyme and using method thereof.
For realizing object above, the invention provides techniques below scheme:
A kind of universal fruit coating antistaling agent based on lysozyme, the raw material composition of this antistaling agent includes lysozyme, chitosan, calcium propionate, ascorbic acid and water, and the weight ratio of lysozyme, chitosan, calcium propionate, ascorbic acid, water is 0.01 10: 0.1 2: 0.01 20: 0.1 20: 80 99;
The pH of described antistaling agent is 56.
Described lysozyme, chitosan, calcium propionate, ascorbic acid, water weight ratio be 0.05: 1.5: 0.5: 0.2: 96.75.
Described lysozyme is egg white lysozyme, its activity >=25000U/mg;
Described calcium propionate is eggshell source calcium propionate;
Described chitosan is the CMC of deacetylation 90%.
It is 0.2 10: 0.01 10 that the raw material composition of described antistaling agent also includes the weight ratio of citric acid, described citric acid and lysozyme.
It is 0.1 10: 0.01 10 that the raw material composition of described antistaling agent also includes the weight ratio of glycerol, described glycerol and lysozyme.
The using method of a kind of above-mentioned universal fruit coating antistaling agent based on lysozyme, comprises the following steps successively:
Step one: first be dissolved in the water to form mixed solution in required ratio by lysozyme, calcium propionate, ascorbic acid, mixed solution is added while stirring chitosan to obtain lysozyme fresh-keeping liquid again, finally regulate the pH to 56 of lysozyme fresh-keeping liquid to obtain antistaling agent;
Step 2: first by above-mentioned antistaling agent dip-coating or spray at fruit surface, then dry, wherein, described flash-off time is 10 40min, now, based on lysozyme universal fruit coating antistaling agent use complete.
Compared with prior art, the invention have the benefit that
null1、The present invention includes lysozyme a kind of composition based on the raw material in the universal fruit coating antistaling agent of lysozyme、Chitosan、Calcium propionate、Ascorbic acid and water,Lysozyme、Chitosan、Calcium propionate、Ascorbic acid、Its weight ratio of water is 0.01 10: 0.1 2: 0.01 20: 0.1 20: 80 99,And the pH of antistaling agent is 56,On the one hand,This antistaling agent adopts lysozyme and calcium propionate simultaneously,Antibacterial (being mainly gram positive bacteria) is not only had obvious inhibitory action by lysozyme,Fungus and virus also there is certain inhibitory action,Calcium propionate is to gram negative bacteria、Mycete and yeast etc. have obvious inhibitory action,And both materials stability in acid condition and bacteriostasis all stronger,On the other hand,The content of chitosan is relatively low,Antistaling agent dip-coating or spray 10 40min after fruit surface can dry,Easy to operate.Therefore, the present invention not only scope of restraining fungi is relatively wide, and bacteriostasis is relatively strong, and is prone to dry.
2, a kind of universal preferred egg white lysozyme of fruit coating antistaling agent lysozyme based on lysozyme of the present invention, calcium propionate preferred eggshell source calcium propionate, compared with other lysozyme, egg white lysozyme has higher heat stability, and eggshell source calcium propionate is higher than the heat stability of commercially available calcium carbonate calcium propionate, Product Activity, purity etc. are even more ideal, and therefore fungistatic effect is more lasting.Therefore, the fungistatic effect of the present invention is more lasting.
3, the present invention is a kind of is added with citric acid based in the universal fruit coating antistaling agent of lysozyme, on the one hand, citric acid is as acidity regulator, chitosan solubilising can be promoted and stable is scattered in solution by regulating the pH of fresh-keeping liquid, on the other hand, citric acid is as organic acid, and it has stronger sterilization and bacteriostasis effect, can work in coordination with antibacterial with lysozyme, thus further enhancing the fungistatic effect of antistaling agent.Therefore, the present invention further increases fungistatic effect.
4, after each raw material is first mixed by the using method of a kind of universal fruit coating antistaling agent based on lysozyme of the present invention, adjustment pH obtains antistaling agent, then antistaling agent dip-coating or spray is dried after fruit surface, simple, convenient, is suitable to commercial production.Therefore, the present invention is simple to operate, be suitable to commercial production.
Detailed description of the invention
The essentiality content of the present invention is further illustrated below in conjunction with embodiment.
A kind of universal fruit coating antistaling agent based on lysozyme, the raw material composition of this antistaling agent includes lysozyme, chitosan, calcium propionate, ascorbic acid and water, and the weight ratio of lysozyme, chitosan, calcium propionate, ascorbic acid, water is 0.01 10: 0.1 2: 0.01 20: 0.1 20: 80 99;
The pH of described antistaling agent is 56.
Described lysozyme, chitosan, calcium propionate, ascorbic acid, water weight ratio be 0.05: 1.5: 0.5: 0.2: 96.75.
Described lysozyme is egg white lysozyme, its activity >=25000U/mg;
Described calcium propionate is eggshell source calcium propionate;
Described chitosan is the CMC of deacetylation 90%.
It is 0.2 10: 0.01 10 that the raw material composition of described antistaling agent also includes the weight ratio of citric acid, described citric acid and lysozyme.
It is 0.1 10: 0.01 10 that the raw material composition of described antistaling agent also includes the weight ratio of glycerol, described glycerol and lysozyme.
The using method of a kind of above-mentioned universal fruit coating antistaling agent based on lysozyme, comprises the following steps successively:
Step one: first be dissolved in the water to form mixed solution in required ratio by lysozyme, calcium propionate, ascorbic acid, mixed solution is added while stirring chitosan to obtain lysozyme fresh-keeping liquid again, finally regulate the pH to 56 of lysozyme fresh-keeping liquid to obtain antistaling agent;
Step 2: first by above-mentioned antistaling agent dip-coating or spray at fruit surface, then dry, wherein, described flash-off time is 10 40min, now, based on lysozyme universal fruit coating antistaling agent use complete.
Principles of the invention illustrates as follows:
The present invention, by forming one layer of chitosan-lysozyme protecting film at fruit surface, stops the CO that fruit Repiration produces2Scatter and disappear, O in air2Infiltration and inside and outside gas exchange, thus preventing fruit from aoxidizing, strengthening fruit surface glossiness, and there is persistency;Simultaneously, owing to the addition of lysozyme, calcium propionate, can effectively suppress the growth of the various putrefaction bacteria that various fruits surface carries, and containing ascorbic acid component, the more effective oxidation preventing fruit, by the extended shelf-life of fruit two to three times, it is adaptable to the preservation and freshness of the various berry fruits such as Fructus Mali pumilae, pears, Garcinia mangostana, Fructus Vitis viniferae.
Lysozyme, calcium propionate: the present invention reaches the effect of efficient fresh-keeping by the synergism of lysozyme, calcium propionate; it is with the use of the various microorganisms that can not only kill fruit surface; and composite protection layer can be formed at fruit surface, it is prevented that gas is subject to the pollution of microbes in air;Due to lysozyme, the too high levels of calcium propionate can increase production cost, content is too low, influences whether the fungistatic effect of antistaling agent, therefore, the present invention is by lysozyme, chitosan, calcium propionate, ascorbic acid, the weight ratio of water controls 0.01 10: 0.1 2: 0.01 20: 0.1 20: 80 99, especially lysozyme, chitosan, calcium propionate, ascorbic acid, when the weight ratio of water is 0.05: 1.5: 0.5: 0.2: 96.75, the antistaling agent obtained can effectively keep fruit freshness, hardness, taste, color pool, carpopodium color pool, emerald green degree, and suppress the mycete of fruit surface to generate.
Chitosan: the N of the preferred deacetylation 90% of chitosan in the present invention, O-CMC, compared with other chitosans, the water solublity of such chitosan is better, therefore water is adopted can it to be dissolved, be conducive to the configuration of antistaling agent and free from extraneous odour, get rid of the drawback bringing pungent tart flavour with tradition dissolution mechanisms such as high-concentration acetic acid solution dissolving chitosans.
The pH of antistaling agent: the pH of antistaling agent is controlled 56 by the present invention, under this pH scope, lysozyme, the stability of calcium propionate and bacteriostasis are all relatively strong, therefore, it is possible to play fungistatic effect more preferably;Meanwhile, under this pH scope, it is possible to fruit is played better color-protecting function, more effective maintenance fruit surface color and luster and brightness.
The all raw materials adopted in the present invention are food grade materials.
Embodiment 1:
A kind of universal fruit coating antistaling agent based on lysozyme, the pH of this antistaling agent is 5, the raw material composition of antistaling agent and weight part ratio thereof are lysozyme 0.05, chitosan 1.5, calcium propionate 0.5, ascorbic acid 0.2, water 96.75, wherein, described lysozyme is egg white lysozyme, its activity >=25000U/mg, and calcium propionate is eggshell source calcium propionate, chitosan is the CMC of deacetylation 90%;
During use, it is sequentially carried out following steps:
Step one: first lysozyme, calcium propionate, ascorbic acid are dissolved in the water to be formed mixed solution in required ratio, then mixed solution add chitosan while stirring to obtain lysozyme fresh-keeping liquid, finally regulates the pH to 5 of lysozyme fresh-keeping liquid to obtain antistaling agent;
Step 2: first by above-mentioned antistaling agent dip-coating at fruit surface, then dry, wherein, described flash-off time is 35min, and now, the universal fruit coating antistaling agent based on lysozyme uses complete.
For detection the present embodiment antistaling agent fresh-keeping effect to fruit, with the fruit of the same race of not film as a comparison case, relatively adopting fruit and the comparative example shelf-life at normal temperatures of the present embodiment, result shows, the shelf-life of the fruit of employing the present embodiment is 3.5 times of comparative example.
Embodiment 2:
Step with embodiment 1, the difference is that:
The pH of described antistaling agent is 6, and the raw material composition of antistaling agent and weight part ratio thereof are lysozyme 0.05, chitosan 1.5, calcium propionate 0.5, ascorbic acid 0.2, citric acid 1, glycerol 1, water 95.75;
During use, it is sequentially carried out following steps:
Step one: first be dissolved in the water to form mixed solution in required ratio by lysozyme, calcium propionate, ascorbic acid, citric acid, mixed solution is added while stirring chitosan again to obtain lysozyme fresh-keeping liquid, then regulate the pH to 5 of lysozyme fresh-keeping liquid, be eventually adding glycerol and mix to obtain antistaling agent;
Step 2: first by above-mentioned antistaling agent dip-coating at fruit surface, then dry, wherein, described flash-off time is 35min, and now, the universal fruit coating antistaling agent based on lysozyme uses complete.
Testing result shows, the shelf-life of the fruit of employing the present embodiment is 4 times of comparative example.
Embodiment 3:
Step with embodiment 2, the difference is that:
The raw material composition of described antistaling agent and weight part ratio thereof are lysozyme 0.01, chitosan 0.1, calcium propionate 20, ascorbic acid 20, citric acid 10, glycerol 0.1, water 99;
In step 2, spraying antistaling agent at fruit surface, flash-off time is 10min.
Testing result shows, the shelf-life of the fruit of employing the present embodiment is 3.2 times of comparative example.
Embodiment 4:
Step with embodiment 2, the difference is that:
The pH of described antistaling agent is 5.5, and the raw material composition of antistaling agent and weight part ratio thereof are lysozyme 10, chitosan 2, calcium propionate 0.01, ascorbic acid 20, citric acid 4.5, glycerol 3, water 90;
In step 2, spraying antistaling agent at fruit surface, flash-off time is 40min.
Testing result shows, the shelf-life of the fruit of employing the present embodiment is 3 times of comparative example.
Embodiment 5:
Step with embodiment 2, the difference is that:
The raw material composition of described antistaling agent and weight part ratio thereof are lysozyme 4.2, chitosan 0.8, calcium propionate 4.2, ascorbic acid 5, citric acid 0.01, glycerol 0.01, water 80;
In step 2, flash-off time is 20min.
Testing result shows, the shelf-life of the fruit of employing the present embodiment is 3.6 times of comparative example.