CHANGES OF THE CHARACTERISTIC AROMA COMPONENTS OF MISO BY HEATING AND FORMATION OF THESE COMPONENTS BY YEASTS.

采用顶空挥发性分析（HSV）和气相色谱-嗅觉分析（GC-O）方法研究了味噌加热后香气变化的机理。生味噌中多种香气成分的浓度降低，在HSV中有几种香气成分在加热后重新形成。从化学分析和统计分析的结果证实了HEMFf（4-羟基-2（或5）-乙基-5（或2）-甲基-3(2H)-呋喃酮）对大米味噌香气的感官评价有显著的贡献。据报道，大麻提纯后是不稳定的。通过加热在添加了HEMF的混悬液的HSV中鉴定出具有难闻气味的2,3-己二酮，确认其为HEMF的降解产物。采用气相色谱- o分析法测定了生味噌和加热味噌中各香气成分的风味稀释系数。通过对生味噌与加热味噌的FD因子的比较，认为加热味噌的香气变化主要是甲基新生成，3-甲基-1-丁醇消失。研究了酵母产生麻麻的过程，探讨了麻麻产生的机理和影响因素。在热灭菌的培养基中，酵母培养促进了HEMP的形成，培养基中含有葡萄糖、核糖和含氮化合物，如shoyu koji的提取物、多蛋白胨、casamino acid或氨基酸（谷氨酸）。苏氨酸。丝氨酸或丙氨酸)。

The mechanisms of the changes of aroma in miso by heating were investigated by the methods of head-space volatile (HSV) analysis and Gas Chromatography-Olfactometry (GC-O) analysis. The concentrations of many aroma components in raw miso decreased, and the sevral aroma components were formed newly in HSV by heating.HEMFf(4-hydroxy-2(or 5)-ethyl-5(or 2)-methyl-3(2H)-furanone) was confirmed to contribute remarkably to sensory evaluation of rice-miso aroma from the results of chemical and statistical analyses. HEMP was reported to be unstable when it was purified. 2,3-Hexandione having un-pleasant smell, was identified in the HSV of the HEMP-added misosuspension by heating, and was confirmed to be degradation product of HEMF.The flavor dilution (PD) factor of each aroma component in raw and heated miso was determined on GC-O analysis. By comparison of FD factor between raw and heated miso, the changes of aroma in miso by heating were considered that methional was formed newly and 3-methyl-1-butanol disappeared.The formation of HEMP by yeast was examined in an attempt to investigate its mechanism and involved factors. HEMP formation was promoted by yeast cultivation in a heat-sterilized medium which included glucose, ribose, and nitrogenous compound such as an extract of shoyu koji, poly-peptone, casamino acid, or an amino acid (glutamic acid. threonine. serine, or alanine).