The “stored off-flavor” is considered to be the off-flavor of citrus fruits stored for a long time, but the details are not clear. In this study, we aimed to provide basic information on storage off-flavor by tracking the temporal trends of it and related substances in edible parts of mandarins (Citrus unshiu Marc.) using olfactory sensory evaluation and chemical analysis techniques. As a result of the olfactory sensory evaluation, the impression of “grass-like” odor clearly increased with storage periods (5 months) in cold storage (4°C). As the results of GC-MS/MS target analysis method, the emission of p-cymenene, a candidate substance for stored off-flavor, was significantly increased with the passage of time in cold storage (4°C). As the results of GC-MS non-target analysis method, the 13 terpenes which increased with time in cold storage (4°C) were annotated (tentatively identified).

“Funazushi” is a traditional fermented fish product in Japan. The bacterial flora and aroma compounds of funazushi were investigated to elucidate the manufacturing method preferred by modern people. Funazushi was classified into 6 groups by dominant bacteria such as Lactobacillus spp., Lb. acidipiscis, Lb. buchneri, Lb. brevis, Bacillus spp. and Staphylococcus spp.. The characteristics of the aroma components detected in the funazushi could be divided into three groups, corresponding to the top, middle, and bottom funazushi in the competition score, respectively. Among the funazushi samples that received high scores in the competition, many aroma compounds common to sake were detected. On the other hand, rancid odor components were detected in the low scoring samples. It was shown that the preference for funazushi can be explained by the aroma compounds. On the other hand, no clear relationship between preference and bacterial flora was observed. Temporal trend of the variation on bacterial flora during fermented period was required.

We analyzed the aroma components of Pueraria montana var. lobata Ohwi (known as kudzu in Japanese) using gas chromatography-flame ionization detection and GC-mass spectrometry. Among the components extracted from flowers, esters occupied the largest relative peak area, which was mainly attributed to methyl anthranilate (28.76%), which is responsible for the characteristic flavor of the Concord grapes. Other components included ethyl linoleate, 1-octen-3-ol, (Z)-3-hexen-1-ol, farnesol, and palmitic acid, which presented the fruity, mushroom, fresh green, floral, and waxy odors respectively, together contributing to the unique aroma of kudzu flowers. This report is the first study on the aroma components of kudzu flowers.