76C-16 |
Machine vision quantification of color changes in quince slices treated with different solutions |
A. Z. ODABASI, N. Demir, and M. O. Balaban. Department of Food Science and Human Nutrition, University of Florida, P.O. Box 110370, Gainesville, FL 32611 Quince (Cydonia oblonga) is a native of southwestern Asia. Turkey is the main producer (100,000 MT in 2001). Although the fruit is softer and juicier in warmer climates, it can be unpalatable in other areas and mostly used in preserves. Enzymatic browning of quince can be monitored using color machine vision (CMV), a non-destructive method suitable for non-uniform colors and surfaces. The objectives of this study were to quantify the changes in the color of quince slices dipped in selected concentrations of various browning inhibitors and to compare their effectiveness using CMV. Quinces obtained from a local market were washed, sliced, and dipped into the following solutions (w/v) for 1 h: 0.5% ascorbic acid (AA), 0.01% 4-hexylresorcinol (4HR), 0.01% sodium metabisulfite (SMBS), honey in water (1:1) and sugar in water (1:1) (w/w), water (control). Images of samples were captured every 15 min or 30 min for 10 h using a video camera. Samples were then stored under refrigeration for ten days in a closed tank RH=100%. Images were taken every 24 h. A color analysis software was used to calculate average L a b values and % color composition of the slices. For the first 10-hour storage, honey and sugar dips were equally effective, and 4HR was slightly less effective than SMBS. Upon further storage, 4HR and sugar improved over SMBS and honey, respectively. On the 10th day, the decrease in L values of 4HR, SMBS, honey and sugar dipped samples were 60.71%, 56.46%, 48.65% and 60.25%, respectively. AA behaved similar to the control group. Percent color changes and their kinetics constants will be presented. Browning inhibitor alternatives to sulfites have been shown to be effective on quince slices. Further work is needed for sensory and microbial evaluation of the product.
Session 76C, Fruit & Vegetable Product: Fresh Fruits and Vegetables
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