39B-35

D. A. OLSON, C. C. Huxsoll, and T. H. McHugh. Process Chemistry Engineering, USDA-ARS-WRRC, 800 Buchanan Street, Albany, CA 94710

Restructured products utilizing concentrated fruit or vegetable purees as primary ingredients, allow for extended uses of agricultural commodities and provide alternative sources for incorporating additional fruit or vegetable material into the diet.

The objective of this research was to assess relative changes in product quality parameters during storage of a model fruit product.

A model fruit product was developed using an alginate base containing calcium and sequestering agents to allow for handling of the depositing mixture. Apple pieces were suspended in the alginate gel matrix. Samples were split into two groups, pasteurized and non-pasteurized. Measurements of moisture, water activity, ascorbic acid, color and microbial counts were taken at 12 weekly intervals during storage at 0°C, 5°C, 10°C and 20°C.

Results indicated that moisture and water activity were stable in the gels with an average water activity of 0.970 and moisture content of 70%. Samples stored at higher temperatures showed considerable changes in CIELAB color values with pasteurized 20°C samples decreasing in lightness at a rate of L*=0.2 units/day. Redness increased at a rate of a*=0.1 units/day and yellowness increased at a rate of b*=0.02 units/day. Ascorbic acid in the pasteurized samples decreased as a first order reaction with rates at 0°C k=0.022/day and 20°C k=0.056/day. Aerobic plate counts showed no appreciable growth throughout the test. Yeast and mold increased in population during storage of the non-pasteurized samples, but showed no appreciable growth in pasteurized samples.

This research demonstrates storage viability at varied temperatures of a new value added fruit product.