Quality characteristics of sweet potato leaves (Ipomoea batatas L.) as influenced by processing and storage conditions

Abstract

This study investigated the effects of blanching, drying and storage conditions on the quality characteristics of sweet potato leaves (SWPL). SWPL (unblanched and steamed blanched at 90 C for 1 min) were oven-dried (50 C for 72 hours), packaged in polyethylene bags, stored at ambient temperature (28±2 C) and refrigerated (7±2 C) for nine weeks. The rehydration ratio, beta carotene, phenolic content, mineral content, and their soup sensory properties were determined at three weeks intervals using standard methods. Rehydration ratio, beta carotene and phenolic contents ranged from 9.46-10.50, 0.10-0.70 g/100 g and 16.40-29.20 g/100 g respectively. The refrigerated blanched samples contained a greater amount of calcium (496.35) and zinc (1.64) than unblanched samples at the end of nine-week storage. The soups prepared from refrigerated blanched dried SWPL were rated similar to fresh SWPL. The combined processing methods of blanching, drying and refrigeration preserved the nutrients in SWPL with better rehydration and organoleptic properties.