Changes in provitamin A and vitamin C contents during storage of 'Mogi' loquat fruit were studied. For determination of provitamin A, the fruits were packaged in perforated polyethylene bags and stored at 18°C, 5°C and 1°C. In carotenoids of 'Mogi' fruits, β-carotene and cryptoxanthin were detected as provitamin A active compounds. β-Carotene content did not decrease during the storage at all of three storage temperatures, and cryptoxanthin content was almost constant. The vitamin A activity of loquat fruit calculated from provitamin A content showed high nutritive value of 600-850 IU/100g f.w. throughout the storage period.
For determination of ascorbic acid, loquat fruits were packaged in sealed or perforated polyethylene bags (30μm thickness) and stored at 18°C and 1°C. The total ascorbic acid in the fruit stored at 18°C tended to increase, while it decreased progressively in both of two packaging conditions at 1°C. Ratio of reduced ascorbic acid to total ascorbic acid was low showing about 30% even at harvest, and it furthermore lowered during storage.

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Mature-green Japanese apricot (Mume, Prunus mume SIEB. et Zucc.) cv. Shirokaga was stored at 15°C by W-Step Modified Air System CA (MASCA), which was developed as an economical CA storage facility, and its efficiency for extension of shelf life of fruits was investigated. 1) The concentration of oxygen and carbon dioxide in the CA chamber was maintained within the range between 1.5 and 3.5% for oxygen and 3 and 5% for carbon dioxide, respectively. 2) As compared with the storage at 15°C under air, MASCA markedly reduced the rate of respiration. Evolution of ethylene was not observed during MASCA storage. A marked increase in respiration rate of MASCA-stored fruits was first detected on 6 days after removal from MASCA. Ethylene was evolved during climacteric rise and caused after-ripening. 3) MASCA well retained chlorophyll of fruits and their green color. 4) Neither browning or off-flavor nor chilling injury was observed. 5) MASCA retarded the metabolism of organic acids and sugars, but it affected little for the latter compounds. 6) As a result, MASCA was decidedly beneficial in retarding ripening of mature-green Japanese apricot fruits, and the MASCA-stored fruits were still in good condition for distribution.

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As an aid for quality control through postharvest handling, volatile constituents in white peaches CV. Hakuto were analysed to estimate the effect of holding temperature on the development of volatile constituents.
“Hard mature” fruits were held at 10°, 20° and 30°C and 85% humidity for 6 days. Volatile constituents were analysed by gas chromatography and gas chromatograph-mass spectrometry.
1) The volatile concentrate of peaches held at all conditions were separated by capillary gas chromatograph into 89 or more peaks, of which 33 were identified by gas chromatograph-mass spectrometry.
2) The volatile constituents were classified by functional groups into 11 kinds of lactones. 2 aldehydes, 7 alcohols, 4 terpenoids, 6 esters and 3 miscellaneous.
3) At harvest, C₆ aldehydes and alcohols which generate “green aromas” and lactonic compounds which generate “fruity aromas” were present. Little or no change occurred in the volatiles in fruit held at 10°C for 6 days.
4) In contrast, when fruit were held at 20°C or 30°C for 6 days, many of the C₆ compounds decreased as a composition ratio of the total volatiles, whereas the lactonic compounds and linalool increased with advancing ripeness. However, at 30°C t-2-hexenol which is typical of the green aroma, was greatly increased.
5) Based on the evaluation of odor threshold, it was demonstrated that increasing levels of lactonic compounds contributed to the fruity aroma in peaches, whereas a decrease in the level of C₆ compounds contributed to the loss of the green aroma during ripening.
6) From the above results, the suitable temperature for the development of a acceptable peach aroma is approximately 20°C.

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