The Interaction Between Kokumi Peptides From Agaricus Bisporus And Five Basic Tastes

With the improvement of living standard,people began to pay more attention to the health of diet.Low-salt food gradually received people's preference.As a special sense of taste,kokumi taste combined with other taste substances can cause mouthfulness,continuity and a sense of complexity that enhances the savory taste.In this paper,Agaricus bisporus was used as raw material to isolate the kokumi peptide from it,and the interaction between the kokumi taste peptide and the five basic taste substances was explored by electronic tongue analysis combined with sensory evaluation.This provided ideas for the development of healthy low-salt seasonings.In this paper,the flavor substances in Agaricus bisporus were extracted and separated by high pressure cooking method and ultrafiltration separation method,and three different molecular-weight components were obtained: U1(Mw?1000 Da),U2(200?Mw<1000 Da)and U3(Mw < 200 Da).The results of the sensory evaluation showed that U2 had the strongest kokumi characteristic.Amino acid analysis showed that the sweet amino acid content(40.95 mg/g)and umami amino acid content(52.16 mg/g)in U2 peptides were higher than the other two components,which may be the key substances that made U2 show kokumi sense in chicken soup.The peptide content of the component U2 was determined to be 14.3%.The component U2 was subjected to gel chromatography and five gel separation components were obtained(F1~F5).The results of sensory evaluation showed that the kokumi intensity of F5 was the strongest.The peptide content of fraction F5 was determined to be 56.8 %.The component F5 was then subjected to reverse phase liquid chromatography to obtain five subcomponents(S5.1~S5.5).Sensory evaluation results showed that only S5.1 exhibited strong kokumi taste.The peptide content of the fraction S5.1 was determined to be 93.4 %,and its purification degree was found to be quite high.Then the peptide in component S5.1 were isolated and identified by ultra-performance liquid chromatography-quadrupole time-of-flight secondary mass spectrometry.The structural sequence of the Agaricus bisporus kokumi peptide was Gly-His-Gly-Asp.The synthesis of the kokumi peptide Gly-His-Gly-Asp in Agaricus bisporus was carried out by Fmoc solid phase synthesis.The taste threshold of the synthetic peptide in chicken soup was 0.28mmol/L according to taste dilution analysis.At the same time,the sensory evaluation of its taste characteristics was carried out.It was found that Gly-His-Gly-Asp showed a sense of mouthfulness,continuity,and kokumi characteristics which is consistent with the taste characteristics of glutathione standards in chicken soup.The results of the sensory evaluation confirmed that Gly-His-Gly-Asp is a kokumi peptide.The kokumi peptide Gly-His-Gly-Asp was added to salty(NaCl),umami(MSG),sweet(sucrose),sour(citric acid),and bitter(caffeine)solution at different concentration gradients.In the solution of five basic taste substances,the sensory evaluation and electronic tongue detection of the prepared binary solution were carried out,and the interaction was analyzed: the salty intensity of the NaCl solution firstly increases with the concentration of the kokumi peptide and then decreases,when the concentration of kokumi peptide is 0.10 g/L,the salt-increasing effect is the best.As the concentration of kokumi peptide increasing,the umami intensity of MSG solution first increases and then decreases,when kokumi peptide concentration is 0.25 g/L,the umami-increasing effect is the best.With the increase of the concentration of kokumi peptide,the sweet intensity of the sucrose solution first increases and then decreases,when the concentration of the kokumi peptide is 0.05 g/L,the sweet-increasing effect is the best.As the concentration of kokumi peptide increasing,the sour intensity of citric acid solution gradually decreases,and the sour intensity is inversely proportional with the concentration of kokumi peptide.The bitterness intensity of caffeine solution first increases with the concentration of kokumi peptide and then decreases,finally it increases again,when kokumi peptide concentration is 1.0 g/L,the bitter-depressing effect is the best.Finally,the Agaricus bisporus low-salt sauce was prepared by adding Agaricus bisporus flavor extract containing kokumi peptide.The sensory evaluation experiment and orthogonal test were used to optimize the raw material ratio of the low-salt sauce of Agaricus bisporus.The best formula of the low-salt sauce of Agaricus bisporus was 60 g of water,30 g of flavor extract,0.4 g of salt and 1.5 g of Agaricus bisporus powder,with sugar 0.2 g,MSG 0.2 g,yeast extract 0.1 g,disodium 5'-ribonucleotide 0.1 g,turmeric powder 0.05 g,palm oil 6 g,maltodextrin 2 g,corn starch 3 g and food flavor 0.02 g.It was verified that the flavor and salty intensity of the Agaricus bisporus low-salt sauce prepared under the optimal formula was significantly higher than that of the sauce prepared without the addition of Agaricus bisporus extract.