Method for preparing biological fresh-keeping agent by using feather degradation liquid through probiotics and application of biological fresh-keeping agent in litchi fresh-keeping
The preparation of biological preservatives by degrading feathers by microorganisms and inoculating probiotics for fermentation, solved the problem of lychees being prone to browning and rot after harvest, and achieved the preservation effect of lychees at room temperature. They were safe, economical and environmentally friendly, and extended the lychees shelf life.
Patent Information
- Application Number
- CN202411422661.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-12
- Publication Date
- 2025-01-14
AI Technical Summary
Lychee fruits are prone to browning and rotting after harvesting, resulting in a decline in quality and loss of economic value. The existing preservation technology has edible safety risks and high costs, and there is no study on using feather degradation solution as fruit preservatives.
The abandoned feathers are degraded by microbial degradation to form feather degradation solution, and the solution is used as a substrate to inoculate probiotic fermentation, prepare biological preservatives, and spray them on the surface of lychee fruits to achieve post-harvest preservation.
It has achieved the extension of the shelf life of lychees after harvest at room temperature, significantly improved the shelf life of lychees, and is safe, economical and environmentally friendly, and enhanced the use value of discarded feathers.
Smart Images
Figure CN119302353A_ABST
Abstract
Description
Technical field:
[0001] The invention belongs to the technical field of fruit preservation, and particularly relates to a method for preparing a biological preservative by using feather degradation liquid with probiotics and an application of the method in lychee preservation. Background technology:
[0002] Lychee (Litchi chinensis Sonn.) is rich in nutrients such as sugar and vitamins. The fruit has a unique flavor and delicate taste. It has certain medicinal and health functions and is very popular. However, lychee fruits mature in the summer when the temperature is high and the humidity is high. The metabolism is active. The lychee fruits lose water seriously after being harvested, causing browning. Studies have reported that lychee peel contains multiple enzymes such as polyphenol oxidase (PPO) and peroxidase (POD), which produce brown substances by oxidizing phenolic quinones and anthocyanins. In addition, due to the high sugar content of lychees, they are easily infected by pathogens and become corrupt. Therefore, lychee fruits are very likely to brown and rot in a very short time after being harvested, reducing their quality, flavor and nutritional value. This also leads to the export volume of fresh lychees in my country accounting for only about 0.3% of its total production. At the same time, the loss of lychees due to quality change accounts for more than 25% of its total annual production, which not only reduces the economic value of lychees, but also restricts the further development of my country's lychee industry.
[0003] At present, people have reported a variety of litchi preservation technologies, such as atmosphere preservation, refrigerated preservation, chemical reagent preservation, biological antibacterial preservation, edible coating, and ultra-low temperature freezing and locking freshness, which have a certain preservation effect on litchi. However, these technologies have shortcomings such as food safety risks and high costs, so it is necessary to develop a safe, economical and green technology to improve the preservation effect. Studies have found that discarded feathers mainly contain keratin, and the oligopeptides and metabolites in their degradation liquid have certain antibacterial and antioxidant effects. In addition, as a probiotic for fermented dairy products, lactobacillus produces metabolites (such as acids, enzyme inhibitors, and extracellular polysaccharides) that have broad-spectrum antibacterial and antibacterial capabilities against Gram-negative and Gram-positive bacteria, as well as fungi. At the same time, lactobacillus metabolites contain antioxidant peptides, which show different degrees of antioxidant properties and have application prospects in the field of food preservation and preservation.
[0004] A search of relevant literature found that there are many reports on the degradation of waste feathers at home and abroad, but there are few reports on the use of feather degradation liquid as a fruit preservative. In particular, there are no reports on the use of probiotics to ferment metabolites of waste feather degradation liquid to prevent litchi from browning and rotting to achieve post-harvest preservation. Summary of the invention:
[0005] In order to overcome the above problems, the present invention provides a method for preparing a biological preservative using feather degradation liquid by probiotics and an application of the method in lychee preservation. The method comprises the following steps: microorganisms are used to degrade discarded feathers to form a feather degradation liquid containing oligopeptides, amino acids and functional metabolites. The feather degradation liquid is then used as a substrate to inoculate probiotics for fermentation. The fermentation liquid is used as a biological preservative for lychees and sprayed onto the surface of the lychee fruit after harvest to achieve a preservation effect at room temperature.
[0006] The purpose of the present invention is achieved through the following technical solutions:
[0007] A method for preparing a biological preservative using feather degradation liquid by using probiotics comprises the following steps: inoculating Bacillus cereus into a feather degradation culture medium to obtain feather degradation liquid, and then inoculating Lactobacillus helveticus with the feather degradation liquid as a substrate to obtain a fermentation liquid, namely the biological preservative.
[0008] Preferably, the Bacillus cereus is Bacillus cereus C3752, whose NCBI accession number is OM368754.
[0009] Preferably, the Lactobacillus helveticus is purchased from Beina Biotech - Henan Industrial Microbial Strain Engineering Technology Research Center, and its number is BNCC336438.
[0010] Preferably, the feathers contained in the feather degradation medium are chicken feathers, duck feathers or goose feathers.
[0011] Preferably, the feather degradation medium comprises 0.01-0.07% KH 2 PO 4 , 0.02~0.1%K 2 HPO 4 , 1% chicken feather or 1% duck feather or 1% goose feather, the balance is water, pH 8.5.
[0012] Preferably, the method for preparing a biological preservative using feather degradation liquid by using probiotics specifically comprises the following steps:
[0013] 1) Streaking Bacillus cereus C3752 on a conventional LB solid medium to obtain a single colony, inoculating the single colony into a liquid LB medium for overnight culture as a seed solution, and transferring the seed solution to a feather degradation medium for culture to obtain a feather degradation solution;
[0014] 2) inoculating Lactobacillus helveticus into a conventional liquid MRS culture medium to obtain a Lactobacillus helveticus bacterial liquid, and then using the feather degradation liquid in step 1) as a substrate, inoculating the Lactobacillus helveticus bacterial liquid to obtain a fermentation liquid, which is a biological preservative.
[0015] Further preferably, in step 1), the LB solid medium culture conditions are: culture at about 35° C. for 18 to 24 hours.
[0016] Further preferably, in step 1), the conditions for overnight culture in the liquid LB medium are: overnight culture at about 35° C. and 140-180 rpm.
[0017] More preferably, in step 1), the seed solution is transferred to a feather degradation medium sterilized at 121° C. for 15 minutes at a volume ratio of 2-8% inoculation amount, and cultured at about 35° C. and 150-200 rpm for 24-35 hours to obtain a feather degradation solution.
[0018] Further preferably, in step 2), the liquid MRS culture medium is cultured at 35° C. and 150-200 rpm for 15-24 hours.
[0019] More preferably, in step 2), Lactobacillus helveticus bacterial solution is inoculated at a volume ratio of 4-10%, and cultured at 35° C. and 150-200 rpm for 25-40 h to obtain a fermentation liquid.
[0020] The present invention also protects the biological preservative prepared by the method of preparing the biological preservative by using the above-mentioned probiotics and feather degradation liquid.
[0021] The present invention also protects the use of the biological preservative prepared by the method of preparing the biological preservative using feather degradation liquid by a probiotic in the preservation of litchi, wherein the application is to spray the biological preservative directly on the surface of the litchi fruit after harvest, and compare the color change of the litchi peel at room temperature.
[0022] Both feather degradation liquid and Lactobacillus helveticus have antibacterial and antioxidant effects. Lactobacillus helveticus can also secrete enzyme inhibitors. The Lactobacillus helveticus fermentation liquid based on feather degradation liquid has the potential to prevent / delay post-harvest browning of litchi.
[0023] Compared with the prior art, the present invention has the following advantages:
[0024] 1. The present invention uses feather degradation liquid as a raw material to prepare a litchi preservative, which has the characteristics of safety, economy, and environmental protection, and can also improve the high-value use value of discarded feathers.
[0025] 2. The present invention uses the fermentation liquid obtained by inoculating feather degradation liquid with Lactobacillus helveticus liquid as a biological preservative. Compared with directly using feather degradation liquid or Lactobacillus helveticus liquid, this method has greater antibacterial, antioxidant and enzyme activity inhibition potential, and has a higher potential for lychee preservation.
[0026] 3. The preservation process of the present invention is simple and easy. After the lychees are picked, they do not need to be soaked in water. The feather-degrading liquid-based Lactobacillus helveticus fermentation liquid is directly sprayed on the surface of the lychee fruit at room temperature in midsummer to delay the browning time and have a preservation effect.
[0027] Bacillus cereus C3752 was published in NCBI on January 30, 2022: https: / / www.ncbi.nlm.nih.gov / nuccore / OM368754, and its accession number is OM368754. The applicant also holds this strain and guarantees that it will be available to the public within 20 years from the date of application. Lactobacillus helveticus was purchased from Beina Bio-Henan Industrial Microbial Strain Engineering Technology Research Center, and its number is BNCC336438. Description of the drawings:
[0028] Figure 1 This is a flow chart of inoculating Lactobacillus helveticus into feather degradation liquid for fermentation to prepare a biological preservative in Example 1.
[0029] Figure 2 This is a comparison chart of the brown color change of post-harvest litchi fruits after spraying the feather degradation liquid, Lactobacillus helveticus liquid and the biological preservative in Example 2. Specific implementation method:
[0030] It will be appreciated by those skilled in the art that the disclosed techniques in the following examples represent techniques that the inventors have found to work well in the practice of the present invention. However, many changes may be made in the disclosed specific embodiments, and still the same or similar results may be obtained without departing from the spirit and scope of the present invention. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.
[0031] Example 1 Preparation of waste feather degradation liquid and probiotic fermentation thereof
[0032] Bacillus cereus C3752 was activated on solid LB medium, cultured at 35°C for 24 hours to obtain a single colony, and then the single colony was inoculated into liquid LB medium, cultured at 35°C and 160rpm for 12 hours to obtain a seed solution; the seed solution was inoculated into a chicken feather degradation medium sterilized at 121°C for 15 minutes at an inoculation rate of 5% by volume, and cultured at 35°C and 180rpm for 30 hours to obtain a feather degradation solution. At the same time, Lactobacillus helveticus BNCC336438 was cultured at 35°C and 160rpm for 18 hours using MRS medium to obtain a Lactobacillus helveticus bacterial solution. Then, the feather degradation solution obtained above was used as a substrate, and the Lactobacillus helveticus bacterial solution was transferred to the feather degradation solution at an inoculation rate of 8% by volume, and cultured at 35°C and 160rpm for 35 hours to obtain a fermentation solution, which is a biological preservative. The flow chart of this process is shown below. Figure 1As shown, the waste chicken feathers are converted into feather degradation liquid-based Lactobacillus helveticus fermentation liquid by combining Bacillus cereus C3752 and Lactobacillus helveticus BNCC336438 probiotics, which is a biological preservative.
[0033] The chicken feather degradation medium mentioned above: by mass fraction, includes 0.03% KH 2 PO 4 , 0.05%K 2 HPO 4 , 1% chicken feathers, the balance is water, pH 8.5.
[0034] Example 2 Effect of Feather Degradation Liquid-Based Probiotic Fermentation Liquid on Fresh-Preservation of Postharvest Litchi
[0035] The feather degradation liquid, Lactobacillus helveticus liquid and biological preservative in Example 1 were sprayed on the surface of litchi fruit to form droplets, and the control group was sprayed with water to compare the color changes of litchi fruit peel at room temperature in midsummer. Figure 2 As shown, the peel of the litchi in the control group had completely turned brown on the first day, while the peel of the litchi in the experimental group sprayed with Lactobacillus helveticus showed obvious browning and some browning spots on the first day, and had basically completely turned brown on the second day. The peel of the litchi sprayed with the feather degradation liquid showed some browning spots visible to the naked eye on the first day, most of the browning had occurred on the second day, and more than 80% of the litchi peel had completely turned brown on the third day. In contrast, the peel of the litchi sprayed with the biological preservative (Lactobacillus helveticus fermented liquid based on the feather degradation liquid) showed only a small amount of browning spots on the second and third days, and obvious browning appeared on the fourth day.
[0036] Therefore, spraying biological preservatives can keep litchi fruits fresh until the third day after harvest at room temperature. Compared with the control group, the biological preservatives extended the browning time of litchi after harvest by nearly 3 days; compared with litchi in the experimental group sprayed with Lactobacillus helveticus and feather degradation liquid, the biological preservatives extended the browning time of litchi after harvest by 2 to 3 days. This shows that the biological preservatives have a significant preservation effect on litchi after harvest. The reason for this change may be that Bacillus cereus produces biologically active oligopeptides and antibacterial antioxidant substances when degrading chicken feathers. At the same time, Lactobacillus helveticus also synthesizes antibacterial, antibacterial and antioxidant metabolites during the fermentation process using chicken feather degradation liquid, which has an inhibitory effect on the activity of pathogenic bacteria and oxidases (such as PPO and POD) that cause litchi browning, and has the potential to slow down the loss of water in the peel. Therefore, the Lactobacillus helveticus fermentation liquid based on feather degradation liquid can significantly extend the shelf life of litchi after harvest.
Claims
1. A method for preparing a biological preservative using feather degradation liquid by using probiotics, characterized in that: The following steps are involved: Bacillus cereus is inoculated into feather degradation culture medium to obtain feather degradation liquid, and then Lactobacillus helveticus is inoculated with the feather degradation liquid as a substrate to obtain fermentation liquid, which is a biological preservative.
2. The method according to claim 1, characterized in that The Bacillus cereus is Bacillus cereus C3752, and its NCBI accession number is OM368754.
3. The method according to claim 1 or 2, characterized in that: The feathers contained in the feather degradation culture medium are chicken feathers, duck feathers or goose feathers.
4. The method according to claim 3, characterized in that The feather degradation culture medium comprises, by mass fraction, 0.01-0.07% potassium dihydrogen phosphate, 0.02-0.1% dipotassium hydrogen phosphate, 1% chicken feathers or 1% duck feathers or 1% goose feathers, and the balance is water, with a pH of 8.
5.
5. The method according to claim 1 or 4, characterized in that: The specific steps include: 1) Streaking Bacillus cereus C3752 on a conventional LB solid medium to obtain a single colony, inoculating the single colony into a liquid LB medium for overnight culture as a seed solution, and transferring the seed solution to a feather degradation medium for culture to obtain a feather degradation solution; 2) inoculating Lactobacillus helveticus into a conventional liquid MRS culture medium to obtain a Lactobacillus helveticus bacterial liquid, and then using the feather degradation liquid in step 1) as a substrate, inoculating the Lactobacillus helveticus bacterial liquid to obtain a fermentation liquid, which is a biological preservative.
6. The method according to claim 5, characterized in that In step 1), the conditions for culturing the LB solid medium are: culturing at about 35° C. for 18 to 24 hours; the conditions for overnight culturing of the liquid LB medium are: overnight culturing at about 35° C. and 140 to 180 rpm.
7. The method according to claim 5, characterized in that In step 1), the seed solution is transferred to a feather degradation medium sterilized at 121° C. for 15 minutes at a volume ratio of 2-8% inoculation amount, and cultured at about 35° C. and 150-200 rpm for 24-35 hours to obtain a feather degradation solution.
8. The method according to claim 5, characterized in that In step 2), the liquid MRS culture medium is cultured at 35° C. and 150-200 rpm for 15-24 hours.
9. The method according to claim 5, characterized in that In step 2), a Lactobacillus helveticus bacterial solution is inoculated at a volume ratio of 4-10%, and cultured at 35° C. and 150-200 rpm for 25-40 hours to obtain a fermentation liquid.
10. Use of a biological preservative prepared by the method for preparing a biological preservative using feather degradation liquid by using a probiotic according to any one of claims 1 to 9 in preserving litchi, characterized in that: The application is to spray the biological preservative directly on the surface of the lychee fruit after harvest.