COMPARISON OF THE COOKING CHARACTERISTICS AMONG TRUE POTATO SEED (TPS) AND SEED POTATO VARIETIES AFTER MICROWAVE HEATING

Abstract

The microwave heating has become widely popular in potato processing because of its high heating rate, short processing time, and for controlling undesirable changes in starch. In the experiment potato columns of TPS potato ‘BARI TPS-1’ and local potatoes ‘Diamant’, ‘Tel Pakri’ and ‘Romana’ were heated with 50 mL of water for 0, 20, 40, 60, 90, 120, 240, and 300 sec by a microwave oven; and the changes in potato columns were analyzed physiologically and histologically to investigate how potato tuber and starch condition changes in local potato and TPS tubers after microwave heating. The ‘BARI TPS-1’ potato columns resulted comparatively higher rate of weight loss and firmness loss percentage than the other seed potato varieties, indicating that temperature rapidly increased in TPS tuber columns than that of the others. Among local varieties ‘Tel Pakri’ gave a relatively higher weight loss and firmness loss percentage than the others. This study also showed comparatively higher solubility percentage in ‘BARI TPS-1’ tuber than the other local varieties, suggesting rapid disruption of swollen starch granule and faster starch degradation in TPS than the other local potato starches. Scanning Electron Microscope (SEM) images of starch granule showed rapidly ruptured and clumped starch granules in ‘BARI-TPS-1’ than the others, indicating TPS starch might obtain gelatinization temperature within a shorter period of microwave heating than that of the other varieties.