In this study, the fermentation of aqueous dried okara by L. plantarum P1-2 was attempted as a preliminary study to establish a co-culture system of lactic acid bacteria and koji. No bacterial contamination was detected in either commercially available dried okara treated or untreated at 30℃ for 36 hr. However, under the same conditions, Bacillus species were isolated when using 70% hydrous okara prepared by adding water to dried okara in advance. In contrast, no bacterial contamination was detected when using autoclaved 70% hydrous okara. The resultant okara formed aggregations. Twenty grams of dried okara was inoculated with L. plantarum P1-2 pre-cultured in the liquid medium containing soymilk, and adjusted to 70% hydrous content. Then it was incubated under aerobic or anaerobic conditions. As a result, no bacterial contamination was detected in the resultant non-autoclaved 70% hydrous okara. The resultant okara again formed aggregations. However, such aggregations were not observed when using 50% hydrous okara. Subsequently, two hundred grams of dried weight okara were adjusted to 50% hydrous content and were cultured with L. plantarum P1-2. As a result, no okara aggregation nor bacterial contamination was observed, at the same time over 10⁹ CFU/g of L. plantarum P1-2 was detected.

　In this study, changes in the amount of sweetness components in four varieties of commercially available sweet potatoes (Ipomoea batatas L.) were measured after curing, constant-temperature storage, and baking. The relationship between the amount of sweetness components after baking and the degree of sweetness was then examined. The following results were obtained:(1) The total amount of sweetness components after curing treatment increased by 1.13-1.91-fold in all four sweet potato varieties relative to the control. The amount of sucrose increased significantly in "Beniazuma" and "Himeayaka". The amounts of sucrose also increased in "Beniharuka" and "Quick Sweet", but no significant difference was observed. The amount of glucose increased significantly only in "Beniharuka". (2) The total amount of sweetness components after constant-temperature storage increased by 1.20-fold in "Beniazuma" and 1.36-fold in "Beniharuka" relative to the control. By contrast, no change in the glucose contents of "Himeayaka" and "Quick Sweet" were noted. The increase in the amount of sucrose did not differ significantly among all four varieties. However, the amount of sucrose significantly increased in all four varieties after constant-temperature storage relative to the control. (3) The total amount of sweetness components in "Yakiimo" after baking was 15.44-19.33 g / 100 g FW. The amount of maltose, which is the main sweetening ingredient of sweet potato, was 10.47-14.56 g. The degree of sweetness relative to the total amount of sweet ingredients was as follows : "Beniharuka"＝9.8, "Beniazuma"＝9.5, "Himeayaka"＝9.1, and "Quick Sweet"＝8.1. Maltose contributed 46%-57% of the total sweetness components, while sucrose contributed 40%-46%. Therefore, sucrose, similar to maltose, is an important sweetening ingredient in "Yakiimo".

　Loofah (Luffa aegyptiaca Mill.) is an annual vine belonging to the family Cucurbitaceae that is native to Southeast Asia. The immature fruits of loofah are a popular traditional vegetable in the Okinawa Prefecture, Japan. We investigated the distribution of γ-aminobutyric acid (GABA) in loofah fruits. In addition, we also investigated the relationship between the GABA content in loofah and the harvest time. We found that the GABA content in loofah was higher in the placenta than that in the other parts of the fruit, and that the GABA content decreased with fruit enlargement after pollination. Furthermore, we found that loofahs on the market vary substantially in not only fruit length and diameter but also GABA content.

　γ-Aminobutyric acid (GABA) is a non-proteinogenic amino acid that has hypotensive effects. Watermelon (Citrullus lanatus) is one of the fruits widely cultivated from spring to autumn in Japan. GABA content was measured in the edible red flesh, white rind, and peel in the ripe and unripe spring crops and ripe autumn crops of watermelon. Additionally, citrulline and lycopene contents were examined in the edible red flesh of ripe spring and autumn crops. The edible red flesh of ripe spring crops contained 13.6 ± 0.8 mg of GABA per 100 g of fresh weight, approximately two-times higher than that found in ripe autumn crops. In contrast, 101.3 ± 29.5 mg of citrulline per 100 g of fresh weight was measured for ripe spring crops, which was half the amount measured in the ripe autumn crops. Lycopene content was 2.7 ± 0.8 mg/100 g in the ripe spring crops and 2.5 ± 0.3 mg/100 g in the ripe autumn crops. These results suggest that watermelon is an excellent food material for preventing high blood pressure.