The Taste Interaction Of Umami Substances In Edible Fungi

In this paper, the umami intensity of single umami substances and the interation of umami and sour, salty, bitter, sweet taste were detected by using the electronic tongue and human sensory.Then twelve edible fungi commercially were analysed for their umami taste compounds (5’-nucleotides; free amino acids) and subjected to human sensory evaluation and electronic tongue measurements so as to analyze their correlation. The salt intensity can be improved according to the interaction of salt and umami. Low-salt seasoning of pleurotus eryngii was developed.The eight kinds of umami substances were detected by electronic tongue. There was a semi-logarithmic function between the umami response value of electronic tongue and the flavor substance concentration. The sourness intensity was reduced by adding the medium and high concentrations (0.34-1.00g/L) umami substances. Adding the low and medium concentrations (0.08-0.34g/L) umami substances can improve the sweetness intensity of the high concentrations (0.94-4.32g/L) sweet solution and the salty intensity of the low concentrations (0.69-2.00 g/L) salty solution. The low concentration (0.001-0.003 g/L) bitter intensity was reduced by adding the medium and high concentration (0.34-1.00g/L) umami substances.The twelve edible fungi were detected and their umami intensities were evaluated by electronic tongue. The PCA (principal component analysis) and DFA (discriminant factor analysis) could successfully distinguish the varieties of edible fungi. The distinguishable index was 97. The correlation of twelve edible fungi umami taste detected by chemical analysis, human sensory evaluation and electronic tongue measurements were established. The PLS models were used to estimate and predict the umami intensities of the edible fungi.The sensory evaluation, electronic tongue evaluation, and equivalent umami concentration (EUC) showed a good correlation. The correlation coefficient was greater than 0.7, RMSEC (Root Mean Square Error of Calibration) and RMSEP (Root Mean Square Error of Prediction) value was relatively low, the predictability of the model was good.The pleurotus eryngii was hydrolyzed to release more umami substances.The single factor and response surface methods were used to optimize the hydrolysis conditions according to the amino acid contents. The optimal hydrolysis conditions were:0.3%of AO1 edible hydrolysis enzyme, pH 4.54,2 h of hydrolysis time; 0.10% AO2 edible hydrolase, pH 6.46,4h of hydrolysis time,55 ℃ of temperature, and 1:20 of solid-liquid ratio. The actual amino acid content was 83.12 mg/g, and the predictive relative error was 4.89%. Under the optimum conditions, the content of amino acids in hydrolyzate increased by 62.65% compared to the control sample. Adding the diluted 2-fold hydrolyzate to 0.69 g/L of sodium chloride solution could enhance the salty of solution based on the interaction of salty and umami substances. The orthogonal experiment of sensory evaluation was used to optimize the seasoning manufacture condition. The optimum condition was:the proportion of water, hydrolyzate, salt, mushroom powder was 60:30:0.4:1.5 (w/w). (Other ingredients were:1g starch,4g flour,6g palm oil,0.05g ginger powder, 1g soy sauce,0.1 sugar and 1.2g beef. The salty intensity of pleurotus eryngii seasoning was higher than that of the blank sample under optimal conditions.