Multi-component synergistic banana preservative and preparation method thereof

Abstract

The invention relates to a multi-component synergistic banana preservative and a preparation method thereof, and belongs to the technical field of food preservation. The fresh-keeping agent is composed of fulvic acid salt, konjac glucomannan and epsilon-polylysine, and through the synergistic effect of all the components, banana peel browning and fruit water loss are effectively delayed, and microbial growth is inhibited, so that the fresh-keeping period of bananas is prolonged, and the freshness and taste of the bananas are kept. The preparation method of the preservative is simple and comprises the following steps: dissolving the components in water in proportion and uniformly stirring. The fresh-keeping agent has the characteristics of being green, safe, low in cost, remarkable in fresh-keeping effect and the like, is suitable for fresh-keeping treatment of the picked bananas, and effectively improves the quality and economic benefits of the bananas in the storage and transportation processes.

Description

Technical Field

[0001] The invention relates to the technical field of fruit preservation, in particular to a banana preservative based on the synergistic enhancement of fulvic acid salt, konjac glucomannan and epsilon-polylysine and a preparation method thereof. Background Art

[0002] As a tropical and subtropical fruit, bananas are loved by consumers around the world for their rich nutritional value, unique flavor and convenient way of eating. Bananas are rich in nutrients such as carbohydrates, vitamin C, potassium, etc., and are one of the important sources of energy and nutrition in people's daily diet. However, bananas face many challenges in post-harvest storage and transportation, especially the problem of short shelf life, which not only affects the quality and taste of bananas, but also leads to huge economic losses.

[0003] The problem of post-harvest preservation of bananas mainly stems from the combined effects of its physiological characteristics and environmental factors. First, bananas will quickly enter the respiratory climacteric period after being harvested. During this stage, its respiration intensity increases significantly, resulting in rapid decomposition of organic matter inside the fruit, accompanied by the release of a large amount of ethylene. As a plant endogenous hormone, ethylene accelerates the ripening and aging process of bananas, causing the peel to turn black, the fruit to soften, and eventually lead to rot. In addition, bananas are also susceptible to microbial infection during post-harvest storage, such as Penicillium and Anthracnose. These microorganisms will form lesions on the surface of bananas, further accelerating the decay of the fruit and shortening the shelf life. Traditional banana preservation methods mainly include low-temperature storage, chemical preservative treatment, and controlled atmosphere storage. Low-temperature storage is one of the most widely used preservation methods. It inhibits the respiration and ethylene synthesis of bananas by lowering the temperature, thereby delaying the ripening and aging of the fruit. However, bananas are sensitive to low temperatures. When the temperature is below 10°C, bananas are prone to chilling damage, which is manifested as black peel and hard texture inside the fruit, seriously affecting its quality and taste. In addition, low-temperature storage cannot effectively inhibit the growth of microorganisms, and bananas may still be infected by pathogens under low temperature conditions. The use of chemical preservatives is also one of the important means of preserving bananas. Common chemical preservatives include imazalil, prochloraz, etc. These preservatives can effectively inhibit the growth of mold and bacteria and extend the shelf life of bananas. However, the use of chemical preservatives has certain safety hazards. Long-term use may lead to excessive pesticide residues, posing a potential threat to human health. In addition, some chemical preservatives also have certain pollution risks to the environment, which does not meet the development requirements of modern green agriculture. Controlled atmosphere storage is to inhibit the respiration and ethylene synthesis of bananas by adjusting the gas composition in the storage environment, such as reducing the oxygen concentration and increasing the carbon dioxide concentration, so as to achieve the effect of preservation. Although controlled atmosphere storage can effectively extend the shelf life of bananas, its equipment cost is high, the operation is complicated, and the control requirements for the storage environment are strict, making it difficult to be widely used in large-scale production and circulation.

[0004] In recent years, as people pay more and more attention to food safety and environmental protection, the development of green, efficient and safe preservation technology has become a hot topic in research. Biological preservation technology has emerged, which uses natural bioactive substances or microbial metabolites to inhibit the ripening and aging of bananas and prevent microbial infection. For example, natural preservatives such as chitosan oligosaccharides and tea polyphenols are widely used in banana preservation research due to their good antioxidant and antibacterial properties. However, these single-ingredient preservatives often have limited preservation effects and single mechanisms of action in practical applications, making it difficult to meet the diverse needs of banana preservation. In addition, bananas face a series of physiological and biochemical changes during post-harvest storage. As bananas mature and age, their cell structure gradually disintegrates, and the pectin in the cell wall is decomposed, causing the fruit to soften. At the same time, the activity of enzymes such as polyphenol oxidase (PPO) and peroxidase (POD) in bananas increases, which promotes the oxidation and polymerization of phenolic substances in the banana peel to form melanin, resulting in browning of the peel. These physiological and biochemical changes not only affect the appearance quality of bananas, but also their taste and flavor.

[0005] In summary, the post-harvest preservation of bananas is a complex multi-factor problem involving multiple aspects such as physiology, biochemistry, and microorganisms. Although traditional preservation methods can extend the shelf life of bananas to a certain extent, they have the disadvantages of limited preservation effect, safety issues, or high costs. Therefore, it is of great practical significance to develop an efficient, safe, economical and easy-to-operate banana preservative and a preservation method thereof. The present invention is based on this demand and proposes a banana preservative based on multi-component synergy and a preparation method thereof. Among them, the specially made fulvic acid salt can delay fruit ripening, enhance the antioxidant capacity of the fruit, and to a certain extent slow down the production of ethylene; konjac glucomannan can form a protective film on the surface of bananas, reduce water evaporation, inhibit microbial growth, and delay fruit aging; ε-polylysine effectively inhibits bacteria and fungi through its broad-spectrum antibacterial property, reduces the decay rate, and cross-links with konjac glucomannan to adjust the size of the air pores. Through the synergistic effect of multiple ingredients, various problems in the post-harvest preservation process of bananas are comprehensively solved, effectively extending the shelf life of bananas, while maintaining their freshness and taste, and improving the quality and economic benefits of bananas during storage and transportation. Summary of the invention

[0006] One of the purposes of the present invention is to provide a multi-component synergistic banana preservative formula, which specifically comprises the following components in parts by weight: 40-60 parts of fulvic acid salt, 80-100 parts of konjac glucomannan, 4-6 parts of ε-polylysine, and 9000-9600 parts of water.

[0007] Another object of the present invention is to provide a method for preparing the preservative, the specific steps of which include the following: (1) Weigh humic acid salt by weight, add one third of the total amount of water thereto, stir evenly at room temperature to prepare a humic acid salt aqueous solution for later use; (2) Weigh ε-polylysine by weight, add one third of the total amount of water thereto, stir evenly at room temperature, and prepare an ε-polylysine aqueous solution for later use; (3) Weigh konjac glucomannan by weight, add one third of the total amount of water thereto, stir for 5-10 min at a temperature of 50-60° C. and a rotation speed of 200-300 r / min, then add the humate aqueous solution all at once, continue stirring for 5-10 min, then slowly add the ε-polylysine aqueous solution dropwise, continue stirring for another 5-10 min, stop stirring and cool to room temperature, and a preservative can be prepared; The method for using the banana preservative is as follows: soak or spray the preservative on the surface of the banana, and wait for the surface water to evaporate slightly to form a soft film; Among them, fulvic acid salt is a product made from lignite in Yunnan Province according to the method in patent 201610650082.3, and has passed the heavy metal test; Among them, konjac glucomannan and ε-polylysine are commercially available products, and all indicators have been tested to be qualified; Among them, fulvic acid salt, konjac glucomannan and ε-polylysine are used as synergistic active components for preserving bananas.

[0008] The beneficial effects of the present invention are as follows: (1) The product of the present invention can effectively delay the browning of banana peel and the water loss of banana fruit through the synergistic effect of humic acid salt, konjac glucomannan and ε-polylysine, significantly prolong the shelf life and reduce post-harvest losses.

[0009] (2) The ingredients used in the present invention are all food-grade materials, which are highly safe and meet the requirements of green preservation. At the same time, the preparation method is simple, the cost is low, it is easy to apply on a large scale, and it has high economic feasibility.

[0010] (3) The use of the preservative of the present invention can maintain the freshness and taste of bananas, improve the fruit quality, enhance the market competitiveness, and bring significant economic benefits to growers and dealers. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a comparison diagram of the test results of the banana preservative of the present invention. DETAILED DESCRIPTION

[0012] The present invention is further described in detail below in conjunction with embodiments, but the protection scope of the present invention is not limited to the described contents. Example 1

[0013] The banana preservative of this embodiment is prepared from the following components, wherein the components and their weight parts are: 50 parts of fulvic acid salt, 90 parts of konjac glucomannan, 5 parts of ε-polylysine, and 9300 parts of water.

[0014] The preparation method of the banana preservative described in this embodiment has the following steps: (1) Weigh humic acid salt by weight, add one third of the total amount of water thereto, stir evenly at room temperature to prepare a humic acid salt aqueous solution for later use; (2) Weigh ε-polylysine by weight, add one third of the total amount of water thereto, stir evenly at room temperature, and prepare an ε-polylysine aqueous solution for later use; (3) Weigh konjac glucomannan by weight, add one third of the total amount of water thereto, stir at a temperature of 55°C and a rotation speed of 250 r / min for 8 minutes, then add the humate aqueous solution all at once, continue stirring for 8 minutes, then slowly add the ε-polylysine aqueous solution dropwise, continue stirring for another 8 minutes, stop stirring and cool to room temperature, and the preservative can be prepared; Among them, fulvic acid salt is a product made from lignite in Yunnan Province according to the method in patent 201610650082.3, and has passed the heavy metal test; Among them, konjac glucomannan and ε-polylysine are commercially available products, and all indicators have been tested to be qualified; The method of using the banana preservative is as follows: soak or spray the preservative on the surface of the banana, and wait for the surface water to evaporate slightly to form a soft film. Example 2

[0015] The banana preservative of this embodiment is prepared from the following components, wherein the components and their weight portions are: 40 parts of fulvic acid salt, 100 parts of konjac glucomannan, 6 parts of ε-polylysine, and 9000 parts of water.

[0016] The preparation method of the banana preservative described in this embodiment has the following steps: (1) Weigh humic acid salt by weight, add one third of the total amount of water thereto, stir evenly at room temperature to prepare a humic acid salt aqueous solution for later use; (2) Weigh ε-polylysine by weight, add one third of the total amount of water thereto, stir evenly at room temperature, and prepare an ε-polylysine aqueous solution for later use; (3) Weigh konjac glucomannan by weight, add one third of the total amount of water thereto, stir for 10 min at a temperature of 50° C. and a rotation speed of 300 r / min, then add the humate aqueous solution all at once, continue stirring for 10 min, then slowly add the ε-polylysine aqueous solution dropwise, continue stirring for another 10 min, stop stirring and cool to room temperature, and a preservative can be prepared; The source of raw materials and the method of use are consistent with those in Example 1. Example 3

[0017] The banana preservative of this embodiment is prepared from the following components, wherein the components and their weight parts are: 60 parts of fulvic acid salt, 80 parts of konjac glucomannan, 4 parts of ε-polylysine, and 9600 parts of water.

[0018] The preparation method of the banana preservative described in this embodiment has the following steps: (1) Weigh humic acid salt by weight, add one third of the total amount of water thereto, stir evenly at room temperature to prepare a humic acid salt aqueous solution for later use; (2) Weigh ε-polylysine by weight, add one third of the total amount of water thereto, stir evenly at room temperature, and prepare an ε-polylysine aqueous solution for later use; (3) Weigh konjac glucomannan by weight, add one third of the total amount of water thereto, stir for 5 min at a temperature of 60° C. and a rotation speed of 200 r / min, then add the humate aqueous solution all at once, continue stirring for 5 min, then slowly add the ε-polylysine aqueous solution dropwise, continue stirring for another 5 min, stop stirring and cool to room temperature, and a preservative can be prepared; The source of raw materials and the method of use are consistent with those in Example 1.

[0019] Blank control: no preservation treatment was performed.

[0020] Comparative Example 1: The difference from Example 1 is that the components and their weight parts are: 50 parts of fulvic acid and 9300 parts of water, and the other parameters are the same as those of Example 1.

[0021] Comparative Example 2: The difference from Example 1 is that the components and their weight parts are: 50 parts of fulvic acid, 5 parts of ε-polylysine, and 9300 parts of water, and the other parameters are the same as those of Example 1.

[0022] Comparative Example 3: The difference from Example 1 is that the components and their weight portions are: 50 parts of fulvic acid, 90 parts of konjac glucomannan, and 9300 parts of water, and the other parameters are the same as those in Example 1.

[0023] Comparative Example 4: The difference from Example 1 is that the components and their weight portions are: 90 parts of konjac glucomannan, 5 parts of ε-polylysine, and 9300 parts of water, and the other parameters are the same as those in Example 1.

[0024] Effect Example: Longest Shelf Life, Sensory Index Scores and Weight Loss Rate of Bananas The longest shelf life judgment standard: the number of days when bananas with the same initial maturity show obvious local corruption and color and taste changes, and the sensory score after 12 days of storage at room temperature (full score 10 points): 5 points means obvious color change and poor taste; browning index = ∑ (browning level × number of fruits in this level) × 100% / (total number of fruits × highest level), browning index: according to the size of the browning area on the surface of the fruit, the classification is as follows: Level 0: no browning; Level 1: browning area less than 5%; Level 2: browning area 5-25%; Level 3: browning area 25-50%; Level 4: browning area more than 50%; weight loss rate = (initial weight-real-time weight) / initial weight. The test results are shown in Table 1 and Figure 1 As shown (the longer the shelf life, the higher the sensory index score, the lower the browning index and the lower the weight loss rate, the better the preservation effect).

[0025] Table 1 Test results of banana preservative of the present invention

[0026] As shown in Table 1, embodiment 1-3 groups have significant fresh-keeping effect compared to blank and comparative example 1-4 groups.It is not difficult to find from the result of comparative example 1 group that when konjac glucomannan and epsilon-polylysine in the preservative of the present invention are abandoned simultaneously, its longest fresh-keeping period, sensory index score are significantly reduced compared with embodiment 1 group, and browning index and weight loss rate have obvious increase, which means that the dosage ratio of konjac glucomannan and epsilon-polylysine has obvious influence for the fresh-keeping effect of preservative of the present invention.Similarly, as shown in the result of comparative example 2 groups and comparative example 3 groups, when konjac glucomannan or epsilon-polylysine in the preservative of the present invention are abandoned separately, its fresh-keeping effect is also significantly reduced compared with embodiment 1 group, and browning index and weight loss rate have obvious increase, which proves again that konjac glucomannan or epsilon-polylysine have important role in preservative of the present invention. As can be seen from the results of the 4 groups of comparative examples, when the xanthohumate in the preservative of the present invention is abandoned, its longest shelf life and sensory index score are also reduced compared with the embodiment 1 group, and the browning index and weight loss rate are increased, which means that the dosage ratio of xanthohumate also has a significant impact on the fresh-keeping effect of the preservative of the present invention. In addition, it is found through effect comparison that the fresh-keeping effect of any missing of xanthohumate, konjac glucomannan and ε-polylysine is not as good as the simultaneous existence of the three, indicating that a synergistic effect is generated between the three, and the three are indispensable. Therefore, in the present invention, the synergistic fresh-keeping effect produced after the composite combination of xanthohumate, konjac glucomannan and ε-polylysine belongs to an unexpected technical effect.

[0027] In summary, the banana preservative based on the synergistic effect of three natural components of fulvic acid salt, konjac glucomannan and ε-polylysine of the present invention has a good preservative effect, and the active components have an obvious synergistic preservative effect, thereby achieving an unexpected technical effect.

Claims

1. A multi-component synergistic banana preservative, characterized in that The components and weight parts are: 40-60 parts of fulvic acid salt, 80-100 parts of konjac glucomannan, 4-6 parts of ε-polylysine, and 9000-9600 parts of water; The fulvic acid salt is a product made from lignite in Yunnan Province according to the method in Patent 201610650082.3, and has passed the heavy metal test; The fulvic acid salt, konjac glucomannan and ε-polylysine are used as synergistic active components for banana preservation; The preparation method of the banana preservative comprises the following steps: (1) Weigh humic acid salt by weight, add one third of the total amount of water thereto, stir evenly at room temperature to prepare a humic acid salt aqueous solution for later use; (2) Weigh ε-polylysine by weight, add one third of the total amount of water thereto, stir evenly at room temperature, and prepare an ε-polylysine aqueous solution for later use; (3) Weigh konjac glucomannan by weight, add one third of the total amount of water thereto, stir for 5-10 min at a temperature of 50-60° C. and a rotation speed of 200-300 r / min, then add the humate aqueous solution all at once, continue stirring for 5-10 min, then slowly add the ε-polylysine aqueous solution dropwise, continue stirring for another 5-10 min, stop stirring and cool to room temperature, and a preservative can be prepared; The method for using the banana preservative is as follows: soak or spray the preservative on the surface of the banana, and wait for the surface water to evaporate slightly to form a soft film.

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