Effects of heat treatment on the quality and storage life of sweet potato

The effects of heat treatment (50 degrees C) on the sprouting inhibition and spoilage of sweet potato roots (curing temperature: 29 degrees C) stored in wrapper-type cold store (WTCS) were determined during year-long storage. The quality attributes of sweet potato were also evaluated. The results indicated that hot water treatment significantly inhibited sprouting and decay of sweet potato for the storage period. It also showed that there were no significant differences in starch properties in terms of pasting properties, enthalpy and temperatures onset (T-o), peak (T-p) and endset (T-E) of gelatinisation of sweet potato starches among all the treatments, especially between heat-treated and without-heat-treated samples. Also, hot water treatment did not have any significant impact on the internal components' quality of the roots: less than 4% of the year-long stored roots were discarded due to spoilage. Heat treatment supplied a lethal dose of heat to surface pathogens and cauterised the eyes without damaging the nutritional and processing qualities of sweet potato. The success of storage experiments in prolonging sweet potato stored in WTCS by heat treatment was obtained from the effective control of weight loss, sprouting and decay without influence on quality characteristics. This new technique opens a new avenue to prolonging the storage life of sweet potato with good quality and minimal loss. (c) 2006 Society of Chemical Industry