Comprehensive Utilization of scraps from Fish processing

The remaining fish head, fish tail, minced meat, scales, skin, viscera, bone, gallbladder and so on, contain a lot of protein, amino acids, trace elements and vitamins. Using these protein resources, a variety of deep processing products can be made, including soluble edible fish protein meal, liquid fish protein feed, fish scale glue, fish skin glue, bone paste, fish protein calcium sugar, bile pigment calcium salt and bile salt, etc. Comprehensive utilization of fish processing waste can reduce the cost of leading products, increase the added value of aquatic products, maintain the environment, reduce the discharge of waste water and waste, and achieve higher economic, ecological and social benefits. The above products are described as follows.

Soluble edible fish protein meal is rich in nutrition, good water solubility, easy to digest and absorb, can be used as amino acid fortified food base material, milk powder substitute, and can also develop nutritional soup, condiment and fish protein beverage and other products. It is an effective drug for the treatment of diarrhea caused by dyspepsia in children, and it can also be used as a protein source in the food fluid of patients with cancer or postoperative eating difficulties. There are many methods to prepare the product, such as enzymatic hydrolysis, acid hydrolysis, alkali hydrolysis, alcohol extraction degreasing and so on. Especially the enzymatic method is better, which can not only maintain the inherent nutrients of fish, but also taste good and easy to dissolve, so it is a new technology developed abroad recently.

1. Technological process: raw material treatment → enzyme hydrolysis → centrifugation filtration → fish protein hydrolysate → decolorization → vacuum drying → crushing → finished product.

two。 The technological process. Use fish minced meat, fish head and fish tail in the scraps after processing as raw materials, wash and mash them with water. Take the mashed fish paste into the reaction pot, add water to adjust the pH value to 6.5: 7.5, and make the solid-liquid ratio 5 ∶ 8, add 1% ~ 2% protease, react under the condition of 45 ℃ ~ 60 ℃ for 2 hours ~ 4 hours, heat and boil for 10 minutes to inactivate the enzyme, centrifuge filtration, the filter residue is discarded (as fertilizer or feed), the fish protein hydrolysate is obtained. The soluble edible fish protein powder was obtained by decolorizing 10 grams of activated carbon per liter at 65 ℃ for 30 minutes, vacuum drying at 50 ℃ ~ 55 ℃, crushing by ball mill and passing through 200 mesh copper sieve.

Liquid fish protein feed is not only nutritious, but also its protein exists in the form of polypeptides and amino acids, which is more conducive to animal digestion and absorption. The feed preparation methods include molasses fermentation method (using sugar cane to make sugar scraps), acidification method, alkalization method and so on. The acidizing method is as follows.

1. Process: raw material treatment, → acidification, → liquefaction, → finished product → storage.

two。 The technological process. Liquid fish protein feed is made of spoiled fish, low-quality miscellaneous fish, fish head, viscera, etc., which has lost its edible value, is mashed with a hammer crusher, the mashed raw material is placed in an acid-resistant container, and 85% formic acid is added. The dosage is 3.5% of the weight of the raw material, and the pH value of the acidified raw material must be less than 4. The acidified raw materials are placed in an acid-resistant liquefaction pool for liquefaction. The liquefaction time varies with temperature and raw materials, generally 30 ℃ ~ 35 ℃ at room temperature for one or two days. The liquefied fish protein feed was stored in an acid-resistant covered container with a shelf life of 1 ~ 2 years at room temperature.

Third, fish scale glue and fish skin glue are used to extract animal glue from discarded skins and scales in the process of fish processing to replace pig skin, cowhide, mule skin and turtle and turtle carapace. Fish skin accounts for about 5% of the fish body, and fish scales account for about 2.5% and 4%. Therefore, the non-utilization of fish scales and skin is a great waste. Practice has proved that making glue from fish scales and fish skin is one of the best raw materials in animals. Fish scale and fish skin glue can play the same effect of nourishing yin and stopping bleeding as tortoise plate glue and donkey-hide glue, and has a unique effect in moisturizing and tonifying the lungs.