ศูนย์นวัตกรรมเทคโนโลยีหลังการเก็บเกี่ยว

Carbohydrate metabolism during dormancy and sprouting in yam (Dioscorea) tubers: changes in carbohydrate constituents in yam (Dioscorea) tubers during dormancy and sprouting.

Hariprakash, C. S.; Bala Nambisan;

Journal of Agricultural and Food Chemistry Year: 1996 Vol: 44 Issue: 10 Pages: 3066-3069 Ref: 14 ref.

1996

บทคัดย่อ

Changes in tuber carbohydrate constituents were studied in Dioscorea rotundata, D. alata and D. esculenta during dormancy and sprouting for a period of 90 days while stored in open racks in a storage shed at 29 deg C and at a relative humidity of 70%. The dormancy period was measured as the time taken from the first day of storage until the appearance of the first sprout on the tuber. The sprouting pattern was monitored and the tubers analysed at 10-day intervals. Tubers of all 3 species exhibited significant moisture and weight loss during storage, with percentage weight loss being greatest in D. esculenta (31.7%). About half of the total weight loss observed was accounted for during dormancy, while the rate of weight loss was highest during the sprouting period. A decrease in starch content (40% reduction after 90 days in D. esculenta) was the most significant change observed in all 3 species. More than 50% of the reduction in starch took place during the dormancy period and the extent and pat

tern of this decrease was similar in the proximal, middle and distal tuber regions. The mobilization of starch to sugars and its utilization was reflected in fluctuating levels of reducing and non-reducing sugars during the pre-sprouting/sprouting periods. Changes were also observed in the amylose fraction in starch. Chromatographic sugar analysis in tubers indicated the presence of glucose and sucrose in fresh tubers. Fructose and maltose were also detected during dormancy/sprouting periods.