FORMATION BY YEAST OF AROMA COMPONENTS SPECIFIC TO MISO AND EFFECT OF AROMA COMPONENTS ON THE CHANGES OF AROMA IN MISO SOUP BY HEATING

4-羟基-2（或5）-乙基-5（或2）-甲基-3（2H）-呋喃酮（HEHF）首先由作者确定为红咸米（含硫大豆糊）的芳香成分，具有一种强有力、甜的蛋糕状芳香，其阈值低于0.04 ppb。它是一种独特的化合物，在红盐米索和舒尤（Soysauce）中非常丰富。多年来，HEMF的形成是在一个尝试中被审查的，以调查其机制和受影响的因素。HEMF的形成是通过在热类固醇化介质中进行年培养的，其中包括葡萄糖、核糖和一种作为氨基酸的硝酸化合物。有人建议使用HEMF的预固化剂来制备HEMF的酵母，其中可能已经由加热期间的氨基-甲邦基反应产生。Halophilic yeast Z.rouxil，生长在含有KH_2PO_4和MgSO_4·7H_2O缓冲液溶液的核糖和糖基化，形式可以在该介质中的芳香化合物剂量。HEMF was considered to be formed stably in buffer solution of KH_2 PO_4 and MgSO_4·7 H_2 O。在中质中的核糖的集中被认为适合从20到300 mmol。这些结果表明，HEMF可能是由氨基-碳基反应产品的加热核糖和糖基化形成的，以及由Shimoda等人开发的、由加热评估的食品产品的前描述性术语的乙酸醛或类似反应物质。通过气相色谱-流变学方法加热对米索汤中芳香的变化的机制。根据口味稀释（FD）的比较，原始和加热的miso中的每个芳香成分的因素，认为HEMF分解和方法是最近通过加热形成的变化。

4-Hydroxy-2 (or 5)-ethyl-5 (or 2)-methyl-3(2H)-furanone (HEHF) which was first identified by the author as an aroma component of red salty rice miso (fermented soybean paste), has a strong, sweet cake-like aroma with a threshold value of less than 0.04 ppb. It is a unique compound and is abundant in red salty rice miso and shoyu (soysauce). The formation of HEMF by yeast was examined in an attempt to investigate its mechanism and involved factors. HEMF formation was promoted by yeast cultivation in a heat-sterllized medium which included glucose, ribose, and a nitrogenous compound such as an amino acid. It is suggested that HEMF was formed during the cultivation of yeast by using a precursor of HEMF which may have been produced by the amino-corbonyl reaction of pentose with amino acids during heating.Halophilic yeast Z.rouxil, grown in a heat sterilized medium containing ribose and glycine in buffer solution of KH_2PO_4 and MgSO_4・7H_2O, forms appreciable amount of aroma compound HEMF in the medium. The precursor of HEMF was considered to be formed stably in buffer solution of KH_2PO_4 and MgSO_4・7H_2O. The concentration of ribose in medium was considered to appropriate from 20 mmol to 300 mmol. These results were indicated probably that HEMF was formed from amino-carbonyl reaction product heated ribose and glycine, and acetaldehyde or similar reactive substance to acetaldehyde formed by yeast.The changes of aroma in miso soup by heating were evaluated with the odor-descriptive terms of food products developed by Shimoda et al.. The mechanisms of the changes of aroma in miso soup by heating were investigated by the method of Gas Chromatography-Olfactometry. By comparison of the flavor dilution (FD) factor of each aroma component in raw and heated miso, the changes were considered that HEMF decomposed and methional was formed newly by heating.