Method for synchronously preparing metastatic active substances such as chitosan oligosaccharide and astaxanthin

Abstract

The invention discloses a method for synchronously preparing metabiotic active substances such as chitosan oligosaccharide and astaxanthin, which comprises the following steps of: crushing and pretreating prawn shells, mixing the crushed prawn shells with 1-3 percent of agricultural auxiliary materials, inoculating with compound microorganism fermentation liquor, and performing two-stage solid-state fermentation, namely statically fermenting at 30-40 DEG C for 2-3 hours, adding the auxiliary materials to adjust the moisture content to 40-50 percent, and fermenting for 7-10 days. According to the method, shrimp shell waste is used as a raw material, chitin and protein are degraded through a multi-enzyme system, and high-activity metagen substances are generated. The method is environment-friendly, efficient, high in added value of products and suitable for resource utilization of aquatic product processing waste.

Description

Technical Field

[0001] The present invention belongs to the technical field of comprehensive utilization of aquatic products and processing by-products, and in particular relates to a method for preparing postbiotic substances containing chitosan oligosaccharides, astaxanthin, etc. by using shrimp shells as a fermentation matrix. Background Art

[0002] China is the world's major producer of shrimp. During the processing of shrimp, a large amount of waste such as shrimp heads and shells is produced. These wastes contain a large amount of chitin and nutrients such as protein, unsaturated fatty acids, astaxanthin, and minerals.

[0003] In addition to directly steaming and drying offcuts for use as feed in China, they are also used to process and extract value-added products such as chitin and astaxanthin. Chitin is an alkaline polysaccharide second only to cellulose in abundance in nature and second only to protein in nitrogen content. Due to its inherent advantages such as biodegradability, biocompatibility, hygroscopicity, and lack of toxic side effects, it is widely used in the food, environmental protection, agriculture, textile, and chemical industries. Its degradation product, chitooligosaccharides, combines the advantages of chitin with improved solubility (completely soluble in water) and absorbability. They exhibit a variety of biological activities, including immune regulation, antibacterial, anti-inflammatory, lipid-lowering, and anti-tumor properties, and hold broad application prospects.

[0004] The 2013 edition of the "Catalogue of Feed Additives" approved chitosan oligosaccharides and oligochitosans as feed additive ingredients. The National Health and Family Planning Commission's Announcement No. 6 of 2014 also approved chitosan oligosaccharides as a new food ingredient. Astaxanthin is a carotenoid with strong antioxidant activity and the ability to enhance immunity. It has been developed overseas as a health food, pharmaceutical, and animal feed, and has broad development prospects. Traditional chitosan oligosaccharide preparation processes primarily rely on a two-step process: first, chitosan is extracted from shrimp and crab shells using an acid-base method. Subsequently, chitosan oligosaccharides are prepared using chemical, physical, or enzymatic methods using chitosan as the raw material. However, the extraction of chitosan from shrimp and crab shells consumes large amounts of acid and alkali, generating significant amounts of acid and alkali wastewater. Furthermore, resources such as protein, calcium, phosphorus, and astaxanthin remain unutilized, resulting in extremely serious environmental pollution and hindering the sustainable and healthy development of the industry. Astaxanthin in shrimp shells is tightly bound to protein and chitin, making it difficult to extract. Traditional astaxanthin extraction processes use strong acid and alkali treatments, which disrupt the astaxanthin's structure. Currently, enzymatic or microbial fermentation methods are preferred for protein removal before astaxanthin extraction. However, some enzymes are expensive, leading to high production costs. Furthermore, the addition of enzymes increases the protein content in the enzymatic hydrolysate, making subsequent protein removal more complex. For industrial applications, the production cost of recycling shrimp products alone is prohibitively high. Therefore, how to scientifically and environmentally utilize shrimp byproducts, increase economic value, and achieve zero pollution emissions has become a pressing challenge in my country. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for the simultaneous preparation of chitosan oligosaccharides and astaxanthin and other postbiotic active substances, thereby achieving zero pollution emissions; and to simultaneously prepare chitosan oligosaccharides, astaxanthin and other postbiotic active substances through solid-state fermentation, thereby increasing the added value of resources.

[0006] To achieve the above object, the present invention provides the following technical solution: a method for synchronously preparing chitosan oligosaccharides and astaxanthin and other postbiotic active substances, comprising the following steps: Step 1, raw material pretreatment: the shrimp shells discarded in the shrimp processing production are crushed to form a uniform solid fermentation matrix; the agricultural product auxiliary materials are sterilized with wet heat to ensure the subsequent fermentation quality; 1%-3% of the shrimp shell weight of the auxiliary materials are taken and evenly mixed with the shrimp shells.

[0007] Step 2, multi-enzyme system composite microbial fermentation: select composite microbial fermentation liquid of Lactobacillus plantarum, Bacillus subtilis, and Candida utilis, with the inoculation amount being 1%-5% of the total amount of shrimp shell raw materials, and carry out acid hydrolysis conversion of chitin; Step 3, adding agricultural auxiliary materials: select one or two of rice bran, soybean meal, and corn cob powder, and use them in an amount that makes the moisture content of the mixture 40%-50%, mix and stir, and then continue solid-state post-fermentation; Step 4: Dry the fermented material to obtain the postbiotic product.

[0008] Preferably, in step 1, the temperature of the moist heat sterilization treatment is 121° C. and the time is 30 minutes.

[0009] Preferably, in step 2, static fermentation is required at a constant temperature of 30-40° C. for 2-3 hours to construct a multi-enzyme system of microorganisms that is conducive to acidolysis conversion.

[0010] Preferably, in step 3, the solid-state post-fermentation time is 7-10 days.

[0011] Compared with the prior art, the present invention has the following beneficial effects: The present invention uses shrimp shell raw materials, a composite microbial source multi-enzyme system and agricultural auxiliary materials for coordinated solid-state fermentation, and prepares biological postbiotic active products through multi-stage enzymatic hydrolysis. This process has significant advantages: first, the use of solid-state fermentation enzymatic hydrolysis technology to achieve a simple and efficient process flow; second, the entire process meets environmentally friendly production standards, the raw material utilization rate reaches 100%, and there is no waste discharge; third, the obtained high-value-added product has excellent biological activity and stable physical and chemical properties. The present invention can achieve harmless and green utilization of shrimp waste materials, without any discharge of pollutants, realizing clean production, and obtaining high-value-added products containing postbiotic substances such as chitosan oligosaccharides and astaxanthin. DETAILED DESCRIPTION

[0012] The present invention will be described in more detail below by way of examples. These examples are merely illustrative and do not limit the scope of the present invention in any way.

[0013] The present invention provides a technical solution: a method for synchronously preparing chitosan oligosaccharides and astaxanthin and other postbiotic active substances, comprising the following steps: Step 1, raw material pretreatment: the shrimp shells discarded in the shrimp processing production are crushed to form a uniform solid fermentation matrix; the agricultural product auxiliary materials are sterilized with wet heat to ensure the subsequent fermentation quality; 1%-3% of the shrimp shell weight of the auxiliary materials are taken and evenly mixed with the shrimp shells.

[0014] Step 2, multi-enzyme system composite microbial fermentation: select composite microbial fermentation liquid of Lactobacillus plantarum, Bacillus subtilis, and Candida utilis, with the inoculation amount being 1%-5% of the total amount of shrimp shell raw materials, and carry out acid hydrolysis conversion of chitin; Step 3, adding agricultural auxiliary materials: select one or two of rice bran, soybean meal, and corn cob powder, and use them in an amount that makes the moisture content of the mixture 40%-50%, mix and stir, and then continue solid-state post-fermentation; Step 4: Dry the fermented material to obtain the postbiotic product.

[0015] Furthermore: In step 1, the moist heat sterilization temperature is 121°C for 30 minutes. Furthermore: In step 2, static fermentation is performed at a constant temperature of 30-40°C for 2-3 hours to establish a multi-enzyme system that facilitates acidolysis. Furthermore: In step 3, the solid-state post-fermentation duration is 7-10 days.

[0016] Example 1: 1. Take 100kg of shrimp shell waste and crush it to a particle size of ≤100nm; 2. Add 2kg of rice bran, sterilize with wet heat, and mix with shrimp shells; 3. Inoculate 3% compound fermentation broth (Lactobacillus plantarum: Bacillus subtilis: Pichia pastoris = 1:1:1); 4. Stage 1: Static fermentation at 35°C for 3 hours; 5. Second stage: add 10kg of soybean meal and continue fermentation for 7 days; 6. After drying, the postbiotic product was obtained, and the astaxanthin content was 6.70g / 100g and the chitosan oligosaccharide content was 3.71g / 100g.

[0017] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and alterations may be made to these embodiments without departing from the principles of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for synchronously preparing chitosan oligosaccharides and astaxanthin and other postbiotic active substances, characterized in that: The following steps are involved: Step 1, raw material pretreatment: the shrimp shells discarded during shrimp processing are crushed to form a uniform solid fermentation matrix; the agricultural product auxiliary materials are sterilized with wet heat to ensure the subsequent fermentation quality; 1%-3% of the shrimp shell weight of the auxiliary materials are mixed evenly with the shrimp shells; Step 2, multi-enzyme system composite microbial fermentation: select composite microbial fermentation liquid of Lactobacillus plantarum, Bacillus subtilis, and Candida utilis, with the inoculation amount being 1%-5% of the total amount of shrimp shell raw materials, and carry out acid hydrolysis conversion of chitin; Step 3, adding agricultural auxiliary materials: select one or two of rice bran, soybean meal, and corn cob powder, and use them in an amount that makes the moisture content of the mixture 40%-50%, mix and stir, and then continue solid-state post-fermentation; Step 4: Dry the fermented material to obtain the postbiotic product.

2. The method for synchronously preparing postbiotic active substances such as chitosan oligosaccharides and astaxanthin according to claim 1, characterized in that: In step 1, the temperature of the moist heat sterilization treatment is 121° C. and the time is 30 minutes.

3. The method for synchronously preparing postbiotic active substances such as chitosan oligosaccharides and astaxanthin according to claim 1, characterized in that: In step 2, static fermentation is carried out at a constant temperature of 30-40° C. for 2-3 hours to construct a multi-enzyme system of microorganisms that is conducive to acid hydrolysis conversion.

4. The method for synchronously preparing postbiotic active substances such as chitosan oligosaccharides and astaxanthin according to claim 1, characterized in that: In step 3, the solid-state post-fermentation time is 7-10 days.