Textural and pasting properties of potatoes (Solanum tuberosum L.) as affected by storage temperature.

摘要

Effects of storage temp. on texture of raw and cooked potatoes and pasting properties of potato meal were studied. 5 potato cultivars (Kufri Anand, Kufri Lalima, Kufri Chipsona-I and -II and Kufri Sindhuri) were stored at 4, 8, 12, 16 or 20 degrees C (80-90% RH) for 18 wk and then analysed for texture properties (including fracturability, hardness, cohesiveness, adhesiveness, springiness and chewiness) before and after cooking using an Instron universal testing machine. Storage influenced all texture parameters measured for both raw and cooked potatoes regardless of storage temp. Changes in fracturability and hardness values as a result of increasing storage temp. differed between raw potatoes and their cooked counterparts. Amylose contents of potato meal (obtained by freeze drying and milling of fresh or stored potatoes) decreased significantly from 112-158 mg/g in meal from fresh potatoes to 73-111 mg/g for meal prepared from potatoes stored at 4 degrees C. Rapid visco analyser studies showed that pasting temp. decreased with increasing storage temp., while peak viscosity, setback and final viscosity increased. Breakdown in viscosity of meal pastes obtained from fresh samples was markedly higher than that obtained from stored potatoes. Extent of storage changes in textural and pasting properties tended to differ between cultivars.