Changes in the contents of organic acids in pilei, stipes and bases of stipes of fruit-bodies of Hiratake-mushroom [Pleurotus ostreatus (Fr.) Quél] during post-harvest storage at six storage temperatures (-20, 0, 5, 10, 20 and 30°C) and freeze drying process were investigated. (1) In this mushroom, formic, acetic, lactic, glycolic, oxalic, succinic, fumaric, malic, α-ketoglutaric, pyroglutamic and citric acid were identified, and among them malic, pyroglutamic, citric, succinic and fumaric acid were found to be major in pilei and stipes, and malic, pyroglutamic, succinic and fumaric acid were found to be major in bases of stipes. Organic acids compositions were different in pilei, stipes and bases of stipes. (2) The total organic acid content in pilei during post-harvest storage at 20°C for 15 days was found in the range of 3.7-8.2% in dry materials, 4.5-8.4% in stipes and 6.0-10.4% in bases of stipes, respectively. During post-harvest storage, the contents of each element increased without any exception, but organic acids compositions had no change. The contents of organic acids in fruit-bodies during post-harvest storage at six storage temperatures increased with the elapse of storage days and the rise of storage temperatures, and the storage method by low temperature turned out to be an effective way of storing. (3) The contents of organic acids in fruit-bodies during the freeze drying process had no change, and the freeze drying method turned out to be an effective way of storing.

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Changes in the contents of organic acids in pilei and stipes of fruit-bodies of Shiitake-mushroom [Lentinus edodes (Berk.) Sing.] during post-harvest storage at six storage temperatures (-20, 0, 5, 10, 20 and 30°C), freeze-drying process and hot-air drying process were investigated. (1) In this mushroom, formic, acetic, lactic, oxalic, succinic, fumaric, malic, α-ketoglutaric, tartaric, pyroglutamic and citric acid were identified, and among them malic, citric, pyroglutamic, tartaric and fumaric acid were found to be major in pilei, and malic, citric, fumaric and pyroglutamic acid were found to be major in stipes. Organic acids compositions were different in pilei and stipes. (2) The total organic acid content in pilei during post-harvest storage at 20°C for 15 days was found in the range of 1. 4-3. 2% in dry materials, and 1.1-2.0% in stipes, respectively. The contents of organic acid during post-harvest storage increased for the first three days, but it decreased from then on. The contents of fumaric, pyroglutamic and citric acids during post-harvest storage increased for the first three days, but from then on they decreased. The contents of the rest organic acids decreased from the first day. As the storage temperature went higher, the changing pattern of organic acids in fruit-bodies advanced faster, and the storage method by low temperature turned out to be an effective way of storing. (3) The contents of organic acids during the freeze process and hot-air drying process had no change, and those two methods turned out to be an effective way of storing.

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The nature of off-flavor occurring in stored satsuma mandarin (Citrus unshiu Marc.) fruits was investigated with reference to the accumulation of ethanol and volatile sulfur compounds in the fruits.
The fruits were stored at 1°C, 6°C, ambient temperature (10°C±2°C) and 20°C, respectively. Part of them were transferred every one month to the elevated temperature at 20°C with and without hermetical packaging in polyethylene bags (0.03mm thick.).
In juice extracted from the fruits stored at above 6°C, ethanol concentration showed a little change during 2 months and a considerable increase after 3 months, while it decreased in the fruits at 1°C. When the fruits were packaged and transferred to elevated temperature, the ethanol concentration increased rapidly. The behavior of ethanol, however, did not coincide with the occurrence of off-flavor or off-odor.
The volatile sulfur compounds were analyzed with gases taken from cavities of fruits as well as head-space of containers in which juice was sealed, using gaschromatography equipped with flame photometric detector. A single peak was found on the chromatogram, and it was identified as DMS (dimethyl sulfide).
The DMS in cavity accumulated notably in fruit stored at 20°C after a month, and it decreased as the storage temperature lowered. When storage was extended by 2-3 months, the DMS concentration decreased in the fruits stored at 20°C and ambient temperature, while it continued to increase at 6°C. When the stored fruits were transferred to elevated temperature, the DMS concentration increased rapidly regardless of with or without packaging. In the fruits stored at 1°C, however, the increase of DMS was suppressed and the effect became conspicuous when storage was extended by 3 months.
It seems that DMS accumulated over a some level in fruit, about 0.5 ppm, is responsible for off-odor felt as fruit is peeled, but not for off-flavor felt as fruit is eaten.

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The rapid methods for determination of ATP related compounds in muscle by low pressure column chromatography have been studied.
The rapid separation was achieved at a high flow rate of 3 ml/min, by using a Perista Minipump and a small column (φ5 mm×20 mm) packed with an anion exchange resin (AG 1×4, -400 mesh, Cl type).
This made it possible to fractionate ATP related compounds into HxR+ Hx, AMP, IMP, ADP and ATP in about 25 min by the concave gradient elution system. The hydrochloric acid-sodium chloride concentration gradients were prepared with two and three chambered gradient apparatuses.
When the flow rate was reduced to 2 ml/min, the time required for the separation increased to 40 min, but a better separation of each component was obtained at this flow rate.

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