Effect of packaging and storage temperature on the shelf life of crisps from four Kenyan potato cultivars.

摘要

Potato crisps are known to absorb large amounts of processing oil that may undergo oxidation and hydrolysis during storage, depending on packaging and storage temp. These changes may have profound effects and impact negatively on product acceptability. Therefore, this study was designed to determine changes in levels of peroxides, free fatty acids and moisture as influenced by packaging and temp. during storage of crisps processed from 4 Kenyan potato cultivars. Potato tubers were processed into crisps of 1.5 mm thickness at a frying temp. of 170 degrees C for 3.5 min. The crisps were packaged in aluminium foil packs and polyethylene bags commonly used by Kenyan industries and stored at 25, 30 and 35 degrees C for a period of 24 wks. The aluminium foil pack was the most effective at controlling increases in moisture content, peroxide values and free fatty acid levels. Potato cultivar significantly (P <= 0.05) influenced formation of peroxides. Crisps stored at 35 degrees C had a significantly (P <= 0.05) shorter shelf life than those stored at 25 and 30 degrees C. Flavour, aroma and acceptability scores of the crisps significantly (P <= 0.05) decreased and varied with cultivar and storage temp. Hence, results suggest that cultivar, packaging materials and storage temp. are important determinants of the shelf life and safety of crisps.