油処理によるイチジク果実の成熟促進に関する研究 (第2報)

The respiratory and ripening behavior of the oleificated fig fruit during ageing were studied following the treatment with rape seed oil.<br>1. The treated fruit showed a typical climacteric rise in the respiratory drift. That is, respiration rate increased rapidly from the next day of the treatment, reaching a maximum 2 days after treatment. Thereafter the rate sharply declined. Respiratory quotient of the treated fruit at the climacteric maximum was 2.1. The fruit began to color in the skin on and after the climacteric period and matured 6 days after treatment.<br>2. The content of starch in the treated fruit increased for 2 days after treatment and then decreased, in which the content was relatively low. Gradual increasing of the content of reducing sugar was observed. The content attained a maximum at maturity in both treated and untreated fruit, being determined as 12.5% and 13.8% on fresh weight basis respectively.<br>3. The content of malic acid in the treated fruit increased rapidly, attained a maximum 2 days after treatment, and then decreased abruptly. The malic acid content in the treated fruit at maturity was as low as 0.02% on fresh weight basis.<br>4. Net contents of acetaldehyde and ethyl alcohol in a treated fruit increased late in the maturing period of the fruit. However, typical sigmoidal curves were observed as expressed in mg per 100g fresh matter. Namely, the drift rose up rapidly, reaching a maximum 2 days after treatment, followed by the sharp depression and second rising just before maturity.<br>5. Ethylene content in the treated fruit also increased rapidly and reached a maximum 5 days after treatment, just before the maturation of the fruit, afterwards the content decreased.<br>6. Nitrogen and phosphorus contents in the treated fruit decreased gradually as the fruit matured. While, potassium content showed slight increase from 4 days after treatment to maturity, although the content decreased at the early stage after treatment. The contents of the three major elements in the treated fruit at maturity were slightly larger as compared with those in the untreated fruit.<br>7. In both treated and untreated fruits, several endogenous growth substances, such as IAA, IBA, IAN and GA₃ like substances, were identified by paper chromatographic method. Moreover, two different unknown inhibitors were also detected. The activities of IAA and IBA were great at the stage of noticeable coloring in the skin, while the activity of IAN was great at maturity.<br>8. From these data mentioned above, it may be concluded that the duration of the metabolic process is shortened when the fruit is treated with the rape seed oil, and the treated fruit attains maturity more promptly than untreated fruit.