Changes in sugar and starch content in garden peas (Pisum sativum L., 'Kishu-usui') at storage temperatures of 1, 5, 10, 15 and 20°C were studied. HPLC was used to determine the sucrose, raffinose, and stachyose levels. At storage temperatures at or above 10°C, sucrose levels steeply declined in keeping with the increased temperatures. In contrast, at temperatures of 1°C and 5°C, sucrose levels increased during the 1st half of the storage period and decreased thereafter. Raffinose and stachyose increased at all of the temperatures studied, with stachyose expressing a higher increase. At temperatures of 10, 15 and 20°C, stachyose became the predominant sugar after the middle of the storage period. At temperatures ≥ 10°C, starch content increased quickly within a few days after the beginning of storage. At the 5°C temperature, the content increased from the 10th day of storage, but at the 1°C temperature, if increased from the 15th day. The lower the storage temperature, the higher the starch increments became. Judging from the above, the changes in saccharide levels of the stored garden peas were similar to those observed in normal development, leading to the conclusion that the process of maturation was not halted by storage. Even if the temperature of storage was at 1°C, it appeared to be difficult to maintain the quality of garden peas 'Kishu-usui' over a long period of time.

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To clarify the changes in the quality of vegetables accompanying change of cultivars with time, the relationship between fruit quality and cultivars in tomato and sweet pepper were investigated. In the tomato, sugar contents in the fruits of more recent cultivars appeared to be greater than that in the fruits of earlier cultivars. In contrast, ascorbic acid contents in the fruits of recent cultivars seemed to be somewhat lower than that in the fruits of earlier cultivars. On the other hand, sugar contents in the fruits of more recent cultivars of sweet pepper were lower than those in the fruits of earlier cultivars. There were some differences in the quantitative fructose, glucose and sucrose composition among cultivars. In addition, ascorbic acid contents in the recent cultivars of sweet pepper were lower than that in the earlier cultivars.
Aqueous solutions from freeze-dried fruits of tomatoes and sweet pepper inhibited the mutagenicity of Trp-P-2 on Salmonella typhimurium TA 98 and TA 100. No trend was observed between inhibitory activities and the accompanying change of cultivars with time.

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The occurrence of bitterness and changes in the production of bitter compound contents were measured to determine the effect of ethylene (100ppm, C₂H₄) treatment on different tissues (phloem or xylem) of mechanically wounded carrots (MWC) stored at 20°C.
Neither C₂H₄-treated nor untreated carrots showed any apparent decay at the wounded part in MWC during 6 days of storage. Brown pitting injury appeared on the surface at the bottom of the wounded part and a brown cavity appeared in the phloem at the side of the wounded part in the treated MWC, but untreated MWC did not develop these injuries. Bitterness was not induced by C₂H₄ in intact carrots and was not noted in un-treated intact carrot and MWC during 6 days of storage. Bitterness of the wounded part was significant and the bitterness of the phloem was moderate in MWC treated by C₂H₄.
The content of isocoumarin, one of the bitter compounds, increased significantly at the wounded part and slightly in the phloem, while in the xylem no increase was noted in MWC treated by C₂H₄. The accumulation of isocoumarin was not induced in either treated or untreated intact carrots, and MWC was not treated by C₂H₄.
Increases in phenols and reducing sugar contents and decrease in total sugar content were induced by C₂H4 at the wounded part in MWC during 6 days of storage.
We concluded that the occurrence of bitterness and the accumulation of the bitter compound in the carrot were induced by C₂H₄ and wounding.

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The published method and a new method for measuring the respiration rates of fruits and vegetables in modified atmosphere packaging (MAP) are discussed. The principle of the published method was based on the hypothesis that the respiration rate was the same as the permeability rate of gases through the packaging film. If it was used in an unsteady state, the value of the respiration rate by the published method would be lower than the real one. The new method, in which both respiration and film permeability are considered simultaneously, can be used over the whole distribution or storage period, including the steady and unsteady state. The new method seems to be useful for estimating physiological change, such as the respiratory quotient, of fruits and vegetables in MAP under an unsteady state.

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The C₂H₄ induced the occurrence of bitterness and the pitting injury and the combination of low O₂ (4%) and high CO₂ (18%) in the atmosphere suppressed these changes apparently in partially processed carrot (PPC).The PPC showed a decrease in the contents of soluble total sugar (TS) and non-reducing sugar (NRS) and the increase of reducing sugar (RS) by C₂H₄ treatment during holding at 20°C. The low O₂ or high CO₂ in the atmosphere delayed the decrease of TS and NRS and the increase of RS induced by C₂H₄ (20ppm) and the combination of low O₂ and high CO₂ in the atmosphere suppressed these changes apparently during 5 days holding at 20°C.

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The changes of microorganisms and pectic substances of partially processed carrots (PPC) were determined with respect to cutting direction. The increase of microbial counts occurred in all tissues and both lengthwise cut sections (LCS) and crosswise cut sections (CCS). The microbial count in the xylem of LCS increased at a greater rate than those of phloem at 20°C. The counts in both tissues of CCS increased slightly and were similar for experimental periods at 20°C. PPC stored at 1°C contained low numbers of microorganisms and maintained acceptable commercial quality for experimental periods. The concentration of soluble pectic substances (WP) in both tissues of LCS increased and insoluble pectic substances (EP and HP) decreased after onset of decay at 20°C. In the xylem and phloem of CCS, WP did not show significant changes and EP and HP decreased slightly up to the end of the holding time.

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Niacin content in the upper and lower ordinary muscles (0.91±0.06-0.93±0.05 mmol/total tissues) of skipjack tuna showed a much higher level than in the liver or dark muscle. Most (98.4±0.8%) of the niacin was free form, and not bound to protein in the tuna muscle. The amount of the coenzyme forms of niacin, NAD (H) and NADP (H), was scarcely contained in the tuna muscle. The muscle niacin of skipjack tuna was not lost during storage at 4°C for 5 days. These results indicate that the tuna ordinary muscle is an important dietary source of niacin.

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