SHELF-LIFE EVALUATIONS OF LIQUID FOODS TREATED BY PILOT PLANT PULSED ELECTRIC FIELD SYSTEM

Abstract

There is a pressing need to validate the shelf-life extension of Pulsed Electric Field (PEF) treated foods. This study was designed to evaluate the shelf-lives of cranberry juice and chocolate milk as a function of PEF and the interaction of PEF+heat treatments. Cranberry juice was exposed to PEF and PEF+heat (60C), and chocolate milk to PEF+heat (105 and 112C). Microbial analysis and color measurement were performed on untreated and treated cranberry juice and chocolate milk aseptically packaged and stored at 4, 22, and 37 C for 197 and 119 days, respectively. Microbial analysis of cranberry juices demonstrated that the shelf-life of PEF and PEF+heat treated juices stored at 22 and 37 C increased significantly during 197 days (p<0.05). The shelf-life of chocolate milk treated by PEF+105C and PEF+112C increased significantly at all storage temperatures (p<0.05). The PEF nor PEF+heat treatments did not result in any significant differences in color retention of either cranberry juice or chocolate milk (p>0.05). This study presented that PEF and PEF+heat treatments were very effective to increase shelf-lives of cranberry juice and chocolate milk.