INFLUENCE OF CURING ON THE STARCH AND TOTAL SOLUBLE SOLIDS CONTENT OF POTATO TUBERS

Abstract

Mature and immature potato tubers of Diamont and Desiree cvs. were used during the spring and autumn seasons of 1999. Four curing temperatures regimes were used 5 (control), 10,20 and an ambient temperature (28-35) and (10-15)C for both seasons, respectively . Duration period was 10,15 and 20 days for every curing temperature. After curing treatments, all tubers then stored at a cold store at 5+1C and 80-85%. R. H. Tor three months, after that tubers were reconditioned at 20-25 C for one week. Results indicated that mature and immature potato tuber for Diamont cv. showed a highest starch percentage during curing period and throughout storage and reconditioning periods. Total Soluble Solids Content (TSS) was higher in Desiree tubers during curing period as compared with Diamont cv. but that was only in the first season. However, TSS remains high in Diamont tubers till the end of both storage and reconditioning periods. Starch and TSS were high in the tubers cured in the first season, while the reverse was occurred in the second season. Curing period for 15 days significantly increased starch content during curing period in the first season. However, the reverse was happened during the second season.