Investigation Of Umami Taste Substances From Antarctic Krill

Fresh flavor is very popular in Eastern countries,and has been widely accepted as the fifth basic taste that is different from the four basic tastes of sour,sweet,bitter and salty.In recent years,nutritional fresh flavoring is highly favored and growing most rapidly.This type of seasoning contains animal and plant protein hydrolysis products,which can enhance the flavor of food,while supplementing the essential amino acids,small molecule peptides and other nutrients.Antarctic krill is rich in endogenous enzymes: three trypsin-like serine proteinases;one chymotrypsin-like serine proteinase;two carboxypeptidases A(carboxypeptidase A enzyme);two carboxypeptidase B enzyme).The activity of the enzyme inhibition system in Antarctic krill was reduced after death,and the endogenous enzymes made it very easy to autolyze.Antarctic krill contains 77.9%～83.1% water and 11.9%～15.4% protein,and its amino acids meet the WHO/FAO requirements for amino acid pattern of adults/infants.Protein hydrolysis to low molecular weight protein peptides and amino acids after autolysis of Antarctic krill can improve its freshness characteristics;autolysis and exogenous protease hydrolysis to obtain more low molecular weight protein peptides.Therefore,Antarctic krill can be used to prepare fresh flavoring agents.The results of the study are as follows.1.the autolysis process of Antarctic krill was studied.The experimental results showed that the optimal parameters of autolysis were: p H 7.5,temperature 43.2°C,material-to-liquid ratio3.5,and time 5 h.Under these conditions,the yield of autolysis was 113.5%;the moisture content was 95.3 g/100 g,protein content was 2.31g/100 g;the total amino acid content of autolysis was 2.11 g/100 g,of which The percentage of fresh amino acids was 24.64%;the percentage of sweet amino acids was 21.33%;about 72.82% of the molecular weight was below1000 Da.2.The deep enzymatic digestion of Antarctic krill autolysis was studied.The experimental results showed that the best conditions for the deep enzymatic digestion were: alkaline protease,enzyme addition of 2800 U/g,enzymatic digestion temperature of 60 ℃,enzymatic digestion time of 4 h.Under these conditions,the yield of the enzymatic digestion product was 116.2%;moisture content of 96.4 g/100 g,protein content of 3.23 g/100g;total amino acid content of the enzymatic solution was 3.03 g/100 g,of which 27.06% were fresh amino acids and 19.15% were sweet amino acids.About 98.65% of the molecular weight was below 1000 Da.3.The process of compounding seasonings was studied.The experimental results showed that the optimum conditions for the compounded seasoning process,taking the freshness intensity of the product as the index,were: 70% enzymatic digest,1% sugar,4% starch,0.25%yeast extract,4% maltodextrin,1% disodium 5’presenting nucleotide,2% monosodium glutamate,1.5% succinic acid and 4% β-cyclodextrin.Under these conditions,the moisture content of the compounded condiment was 81.22g/100 g and the total nitrogen content was0.732%.4.Translated with www.Deep L.com/Translator(free version)4.The shelf life of the compounded condiments was studied.The shelf life of the product was calculated based on the established kinetic model of colony growth,using the minimum spoilage,the initial total number of bacteria and the maximum number of bacteria.The shelf life of the product was predicted by the time from the initial total number of bacteria to the minimum spoilage,and the experimental results showed that the shelf life under the Gompertz model was 30 days,while the shelf life under the Logistic model model was 33 days.In this paper,the optimal parameters of autolysis of Antarctic krill were studied with the freshness intensity of the product as the index,deep enzymatic digestion of the autolysis solution of Antarctic krill,compounding of the enzymatic digestion products,and shelf-life experiments on the compounded products.The aim is to provide technical and theoretical support for the efficient use of Antarctic krill to produce high-quality nutritious fresh flavor seasonings.Translated with www.Deep L.com/Translator(free version)This paper has 28 Figureures,29 tables and 128 references.