88E-18 |
Effect of storage temperature and time on quality of apple slices |
A. D. CLARKE1, V. Shankaraiah2, L. N. Fernando1, and I. U. Gruen1. (1) Department of Food Science, University of Missouri, 256 Eckles Hall - Stringer Wing, Columbia, MO 65211, (2) Post Harvest Technology of Horticultural Crops, College of Agriculture, Rajendranagar, Hyderabad, 500030, India The preparation of dried apple slices is an example of value-added processing. While browning is a major problem, it may be reduced or prevented by application of preservatives. Other problems, such as development of off-flavors or loss of sweetness, are also encountered with preserved apple slices. The objective of this project was to demonstrate the extent to which storage temperature and time affect selected quality attributes of sliced apples. Apples were washed and rinsed by hand and then sliced with a Cuisinart food processor within a week of harvest. All apple slices were treated with a commercial blend of ascorbic acid and citric acid (Everfresh, Kraft Foods, White Plains, NY) at 0.75% and a 20% sucrose solution prior to being freeze-dried for 72 hr. Dried slices were vacuum packaged and units were randomly assigned to storage at one of three temperatures (-18, 4 or 23 C) for up to 75 days. Samples were evaluated at 15 d intervals for physiological loss of weight (PLW), total soluble solids (TSS), titratable acidity (TA), reducing sugar content (RSC) and flavor desirability (FD). Statistical analysis used storage time and temperature as main effects. The PLW of the 23 C storage temperature was significant and approximately four times greater than the loss at other temperatures. Likewise, the PLW increased throughout storage, regardless of storage temperature. TSS was not different between the 4 and -18 C treatments, but was greater than values for slices stored at 23 C. TA and RSC were unaffected by storage temperature or time. Hedonic scores for flavor of slices stored at 4 or -18 C were unaffected and remained 18-58% higher than the samples at 23 C throughout the storage period. Apple slices prepared by freeze-drying and vacuum-packing require storing at 4 C or less which may reduce feasibility in developing countries.
Session 88E, Fruit & Vegetable Products: Processing
|