Shelf-life of Near-Aseptically Packaged Refrigerated Potato Strips

Abstract

Near-aseptic packaging is an alternative method to extend shelf-life of refrigerated potato strips. This study was undertaken to determine the shelf-life of blanched and near-aseptically packaged refrigerated potato strips based on microbiological, color and textural quality. In near-aseptic packaging, packaging chamber is pasteurized with steam at atmospheric pressure for 30 min then cooled to room temperature and continuously pressurized with filter sterilized air. Potato strips were first blanched at low temperature (60°C) for 10 or 20 min then second blanched at high temperature (98°C) for 1, 5 or 10 min. After 2-step blanching, potato strips were cooled and packaged into polyethylene bags using near-aseptic packaging chamber. Near-aseptically packa ged potato strips were stored at 7°C for 28 days. Microbiological quality was determined by analyzing mesophilic and psychrotrophic bacteria and yeast-mold count. Quality was determined by using L* (lightness) and ?E (total color difference) values for col or and peak force value for texture. Microbial spoilage was observed for strips treated for 1 min in the second blanch. No microbial growth was observed within 28 days of refrigerated storage for strips treated for either 10 or 20 min in first blanching followed by 5 or 10 min in second blanch. Near-aseptically packaged refrigerated potato fries were lighter in color than unprocessed potato fries (neither blanched nor near-aseptically packaged) and less color difference was observed in refrigerated potato fries compared to unprocessed fries. Higher before-frying and lower after-frying peak force was determined in unprocessed potato strips compared to refrigerated strips. No significant changes were observed in the quality of near-aseptically packaged refrigerated potato strips during 28 days storage.