14A-43

M. KYEREME¹, A. Mazzotta, and R. Chuyate. (1) National Food Processors Association, 1350 I Street NW, Washington, DC 20005

Current process recommendations for pH-based hot fill hold (HFH) processes were established using historical data and past experience. The recommendations are based on conservative estimates and call for rather high fill temperatures that may adversely impact product quality.

The objective was to develop a protocol that can be used to optimize HFH processes for juices.

Bench-top temperature mapping studies were conducted in 20oz. and 1.75L polyethylene terephthalate (PET) containers filled with water at 160, 165, 170°F. Type-T thermocouples were used to measure the temperature profile at four locations in the headspace area of the filled container: cap surface, liquid, headspace, and container wall. After filling and capping, bottles were held under the following holding/cooling conditions to simulate HFH processes: Vertical/Air, Vertical/Tunnel, Horizontal/Air, and Brimfill/Air. For each experimental fill temperature, the temperature data at the cold spot were combined with heat resistance data for Saccharomyces cerevisiae to calculate accumulated lethality and number of log reductions from which the minimum fill temperature needed to achieve 5 log reductions of the yeast was calculated. The calculated processes were validated by inoculated pack challenge test for apple juice at a juice processing facility.

Results of the fill temperature calculations will be presented. After a week of incubation at 90°F, all positive controls showed yeast growth while negative controls remained negative. After 18 weeks, most bottles remained commercially sterile but a few bottles became positive.

The results demonstrated that the protocol developed could be used to optimize hot fill hold processes for juices. The procedure could be extended to optimize HFH processes for similar products packaged in different bottle types and sizes.