What are the applications of fish gelatin in the food industry?

Abstract: Fish glue, also known as flower glue and swim bladder, is an important organ for controlling the sinking and floating of fish in the water, and is a good low-fat and high-protein material. In recent years, with the rise of the trend of healthy diet and diversified diet, the development and utilization of fish glue in the food industry has been paid more and more attention because of its high nutritional value, abundant raw material resources, and no restriction of religious factors.
Usually, often with the help of chemical soaking, natural air-drying and other traditional methods of fish glue made of dried products for sale, the need for secondary processing, in recent years there are also a lot of fish glue on the medicinal health care products, ready-to-eat products, food additives, and other new products into the public’s field of vision, not only improve the utilization rate of the relevant aquatic products, but also for the development of new products to provide a new choice.
Application status of fish glue in food industry
1.1 Fish glue is used to make dried semi-finished products At present, the fish glue products on the market are still mainly dried semi-finished products, which need to be processed twice to be eaten. The traditional method of dealing with dried swim bladder is relatively simple, after taking out the swim bladder from the belly of the fish, the swim bladder will be dissected and cleaned and blood stains will be removed, and then it will be air-dried to be preserved.
Nowadays, in order to better preserve the dried swim bladder, many merchants will also improve the quality of the fish bladder by soaking and fumigating it with appropriate medicinal water.
In addition, there is also the production mode of making fish glue directly from swim bladders. Usually, the production of fish glue includes three kinds of treatments: alkali treatment, acid treatment and enzyme treatment. Zhang Lili et al. concentrated the fish glue and solidified it, and then sliced the solidified jelly into uniform slices with a spatula, to make fish glue sheets.
1.2 Fish glue used in the production of medicinal health products fish glue has been regarded as a superior tonic, according to records, fish glue has to improve gastrointestinal digestion, nerve conduction retardation, maternal milk secretion deficiency as well as fixing the kidneys and cultivate essence, blood and blood and other functions.
Chen Jing and others developed a rice swim bladder health wine by adding rice swim bladder enzymatic solution or rice swim bladder crushed products, red date extract and wolfberry extract to the brewing raw materials for co-fermentation before fermentation of yellow wine.
Chi Changfeng et al. developed a method of extracting antihypertensive peptides from the swim bladder of Rheum officinale, i.e., the swim bladder of Rheum officinale was crushed and homogenized, and then extracted with buffer to obtain crude protein, and then centrifuged to obtain the antihypertensive peptides after enzyme digestion.
In addition, Zhang Xuefeng et al. also developed a kind of fish maw stew containing tablets, which can maintain a certain stew flavor, but also can make effective use of the nutrients within the fish glue.
1.3 Fish glue is used to make ready-to-eat products Xu Weiqiang et al. developed a kind of swim bladder meat cake, which is a kind of ready-to-eat swim bladder meat cake obtained after beating, mixing and steaming with swim bladder, pork, sweet potato flour and salt as raw materials.
Zeng Li et al. developed a new type of tea-flavored swim bladder collagen health care jelly by using swim bladder as raw material, extracting collagen, using agar as gelling agent, and oolong tea as deodorizing agent and flavoring agent.
Xia Zhonghai et al. developed a preparation method of frozen ready-to-eat fish maw stew by mixing fish glue with ingredients and then stewing to get a kind of ready-to-eat canned fish glue.
1.4 Fish glue used in the production of food additives Some studies have shown that fish glue has a certain effect on the clarification of wine, He Zhongbao et al. through the study of fish glue in dry red wine under the effect of glue found that the Dongyi fish glue (DOEST) in dry red wine has a better clarification effect, and its clarification effect is better than that of gelatine and saponin.
In order to prepare edible adhesive with excellent performance and moderate cost, Liu Shifeng et al. prepared a high-performance edible adhesive using swim bladder gelatin as raw material, which has a broad application prospect in the food packaging industry, especially in children’s products.
Ni Haiping et al. invented a method involving the preparation of a kelp-flavored seafood seasoning, selecting dried swim bladder as the raw material, ultrasonic treatment after cleaning, crushing, soaking, and then adding ingredients and undergoing certain treatment to produce kelp extract, flavored and canned for preservation. Nutritional Value and Effective Composition of Fish Maw
2.1 Collagen in Fish Maw The protein contained in fish maw is type I collagen, with stable molecular weight. The content of collagen in swim bladder is related to the species and age of the fish. Usually, the collagen content of swim bladder is comparable to that of fish skin and is significantly higher than that of fish bones, scales and other internal organs of fish.
Fish are metameric, and the thermal denaturation temperature of swim bladder collagen is generally slightly lower than that of terrestrial mammalian collagen, which is positively correlated with the content of imines (proline and hydroxyproline).
Since the pyrrole ring in imines can form a stable triple helix structure, fish bladder collagen is more suitable as an alternative source of mammalian collagen for industrial production.
2.2 Amino Acids in Fish Bladder Collagen Compared with mammals, fish bladder collagen has a higher content of serine, leucine, isoleucine, methionine and a lower content of hydroxyproline.
There are some differences in the content of glycine, proline, glutamic acid and aspartic acid in collagen from swim bladders of different fish species, while other amino acids are similar in type and content.
Fish collagen collagen formed high tensile strength and maintained its structural stability through covalent cross-linking such as hydrogen bonding of glycine triplets, while the substable state of proline provided structural flexibility and endowed collagen with a certain degree of flexibility.
Zhang et al. used 12 batches of fish gelatin as the research object and examined 16 amino acids in it, among which glycine (Gly) was the highest, accounting for about 21% of the total amount, followed by proline (Pro), glutamic acid (Glu), alanine (Ala), arginine (Arg), and tyrosine (Tyr) was the lowest, accounting for only about 0.7% of the total amount. Flavoring amino acids and essential amino acids accounted for about 45% and 18% of the total amount, respectively, and the index of essential amino acids is about 35.The current status of utilization of different fish gelatins
At present, the market is dominated by dried fish glue products, but the popularity of different qualities of fish glue in the market varies greatly, bigger and thicker fish glue is more popular, and can be auctioned in the market at a high price, the market quality of the yellow-lipped fish, arowana fish glue, etc. is relatively rare, mostly used for the collection or bidding, the general public to eat the red fish glue, yellow fish glue, the North Sea glue is mainly, and some of the industrial processing of the extracted fish bladder The by-products, on the other hand, are processed with common fish as raw materials.
Discussion and Summary
Fish glue as a kind of beauty and health tonic is gradually recognized by the people, many existing fish glue products have been put into production, with the pursuit of high-quality collagen, the development and utilization of fish glue products also has a better prospect.
The main consumption area of fish glue is the southern coastal area of China, due to the complexity of processing and other reasons failed to open the market, and the existing fish glue on the market is mainly for the yellow-lipped fish and a few other fish, most of the swim bladder of the fish is not fully utilized, although there have been a lot of research attempts to fish glue processed into different products, but most of the products can not be put into production or can not find a market for the development and use of fish glue products is still in the laboratory The development and utilization of fish glue products are still in the laboratory stage of theory, so there is still much room for exploration for the development and utilization of fish glue products.