Study Of Taste Active Components Of Five Wild Edible Mushrooms In Yunnan

Edible mushrooms are famous for their high nutrition and unique delicious flavor, so the use of their flavor properties to improve food flavor is an important direction in natural food additives industry. The flavor of mushrooms including the smell and taste, could be classified into non-volatilized active substance and volatilized armoa substance. The taste such as sweet and umami, could be tasted by tongue, attributed to non-volatilized active substances. The aroma depended on volatile aromatic substances. The unique taste of edible mushrooms mainly depended on some non-volatile substances, such as soluble sugar, free amino acid and nucleic acid metabolites such as guanine nucleotide, inosinic acid.Compared with cultivated mushrooms, the taste of wild edible mushrooms are more delicious and have higher value of nutrition. Wild edible mushrooms in Yunnan have rich resources, five kinds of wild edible mushrooms were studied, namely Boletus speciosus, Boletus auripes, Boletus edulis, Leccinum extremiorientale, Boletus brunneissimus and their umami-taste and sweet-taste components were studied according to different parts (pileus and stipe) by modern analysis technologies, including free amino acid, nucleic acid and souble sugar. The umami-taste free amino acids include Asp and Glu, umami-taste 5’-ribonucleotides include 5’-GMP,5’-IMP and 5’-CMP. Equivalent umami concentrations (EUC) values in pileus and stipes of these five test mushrooms were studied by comparing with the sensory evaluation. The differences of the various taste components were the basis material for the different taste of the edible mushrooms. In this study, the amino acids and nucleotides in the five edible mushrooms were focused to analyse. The results showed that these five mushrooms had variety amino acids and nucleotides. Through comprehensive analysis in these substances of five edible mushrooms showed that their different taste properties dueing to the difference taste components.The main contents and results of the study were as follows:1. The Waters AccQTag derived before column combination with high performance liquid chromatography was employed to analyze 16 free amino acids of2. five kinds wild edible mushrooms (pileus and stipe). Comprehensive survey and analysis of effect of AccQ-Fluor dosage, heating time, the ratio of the mobile phase, the temperature of chromatographic column and the optimum conditions: AccQ Fluor 20 μL,55℃ water bath accurate heating 10 min, the detection wavelength at 248 nm and the temperature of chromatographic column at 37 ℃. The result showed that the five edible mushrooms were richer in flavour amino acids than general edible mushrooms.3. Extraction and high performance liquid chromatography methods were optimized to determine flavor nucleotides of five kinds of mushrooms. The optimized extraction method was boil for 30 min. Chromatographic separations were achieved using a Waters symmetry shield RP18 column (250x4.6 mm,5 μm). The mobile phase was 0.5 M potassium phosphate (pH 4.3 with phosphoric acid) at a flow rate of 1 mL/min and UV detection at 254 nm. The result showed that 5’-GMP was the main umami-taste of 5’-ribonucleotide in edible mushrooms.4. Refractive index detector-high performance liquid chromatography method was used to determine the souble sugar of five kinds of edible mushrooms. Comprehensive survey of the various factors which affect extraction efficiency, including the extraction method, extraction solvent, extraction time were studied and determined the extraction optimal process parameters:ultrasonic extraction,80% ethanol, ultrasonic processing for 30 min, C18 solid phase column out impurities. The results showed that arabia and glucose content were higher than general edible mushrooms.5. A significant difference of five wild edible mushrooms of their EUC values, could be used to commentate the synergistic effect, and the result showed Boletus brunneissimus> Leccinum extremiorientale> Boletus auripes> Boletus edulis> Boletus speciosus. However, the umami taste of the five mushrooms determined by the sensory evaluation was inconsistent with the ECU values, indicating that there might be potential new flavor components.The special significance of studying taste active components of five wild edible mushrooms is to provide important scientific basis for the development and utilization of Yunnan wild mushroom resources. It also has practical significance for better development of the edible mushrooms with added value, as well as study of umami receptors, and its molecular mechanisms.