ABSTRACT
Freshly pressed raw apple juice was obtained from a commercial processor. Clarification was performed by ultrafiltration, centrifugation, or plate filtration. Each of the clarified juices was further processed by pulsed electric field (PEF), high hydrostatic pressure (HHP), or heat exchanger (HE) methods. Processed PEF, HHP, and HE apple juice were stored at both 4°C and 23°C for one month. Viability of yeasts and molds, coliforms, aciduric bacteria, Salmonella spp., and total plate counts were determined. Microbial spoilage was not detected for heat exchanger and HHP processing, regardless of the temperature or length of storage. A maximum shelf life of one month was observed for PEF processed apple juice stored at 4°C. PEF processed apple juice spoiled during storage at 23°C. Sensory evaluation of attributes for raw apple juice were similar for PEF, HHP, and heat processed apple juice. Generally, apple juice volatile flavor compound concentrations were unchanged or decreased slightly after processing, and during 1 month storage.
