Physiological changes in carrot roots during long-term storage.
Takigawa, S.; Ishii, G.;
Research Bulletin of the Hokkaido National Agricultural Experiment Station Year: 1996 Issue: No. 164 Pages: 73-85 Ref: 10 ref.
1996
บทคัดย่อ
Carrots (cultivars Kyaroshi and Koyo-2-gou) were sown in early June, and harvested in late September or mid-October, in field studies carried out in Japan during 1992-94. Roots (packed in open polyethylene bags) were stored at 0 or 5 deg C for up to 200 days from October to May; changes in respiration rate, ethylene evolution and contents of total phenols, sucrose, glucose, fructose, total sugars, beta -carotene, alanine, proline and gamma -aminobutyric acid were monitored. Cultivar differences were observed in respiration rate. Kyaroshi (for table use) showed approximately the same low respiration rate at both temperatures. However, Koyo-2-gou (for processing) exhibited a higher respiration rate at 5 deg than that at 0 deg . There was no apparent difference in ethylene production between the 2 cultivars. The variation in total phenols during storage differed among the 3 years; this is suggested to be due to different climate conditions before harvest and/or the pretreatments (sterilization with
0.02% sodium hypochlorite, with or without air-drying for 2-3 days) carried out before storage. In Koyo-2-gou, sucrose increased but glucose and fructose decreased during storage. In Kyaroshi, the change in sugar content was very small. Kyaroshi was well-suited to prolonged storage because of its low respiration rate and maintenance of sugar levels. The root phloem contained more beta -carotene than the xylem. beta -Carotene in the xylem decreased gradually with time, more than in the phloem. The contents of alanine and proline during storage rose linearly with time, but that of gamma -aminobutyric acid increased immediately after storage, then dropped to a lower level. It is suggested that alanine content may indicate the quality or freshness of stored carrots.