104C-4 |
Effect of gaseous ozone on antioxidant content and color of sliced tomatoes |
S. C. MALONE1, S. Zivanovic1, C. E. Sams2, and J. R. Mount1. (1) Dept. of Food Science & Technology, Univ. of Tennessee, Fresh-Cut Fruits & Vegetables Lab., 2605 River Dr., Knoxville, TN 37996-4591, (2) Dept. of Plant Science & Landscape Systems, Univ. of Tennessee, 2431 Center Dr., Knoxville, TN 37996-4561 Sliced tomatoes are used frequently in restaurants and fast-food establishments. Their limited shelf-life has caused scientists to study treatments to prolong their useful life. Treatments for shelf-life extension have included mild heat treatment and modified atmosphere packaging. Although gaseous ozone has been shown to reduce spoilage microorganisms on produce, limited research has been performed regarding the affect of ozone on antioxidant compounds. Our objective was to evaluate the effect of gaseous ozone on lycopene and ascorbic acid in sliced tomatoes, as well as its effect on tomato color. Tomatoes of uniform size and color (USDA Stage 5) were cut into cross-sectional slices. Slices from the same tomatoes and 1 mL aliquots of 24-h tomato spoilage culture were treated with ozonated air for 0, 90, 105, 120, and 135 min. Lycopene and ascorbic acid contents were determined for each sample and Hunter color measurements were determined on ground tomato samples. No significant differences (p>0.05) in lycopene content were found between untreated tomato slices or slices treated for 90, 105, 120, or 135 minutes. Ascorbic acid content of sliced tomatoes treated with gaseous ozone for 135 minutes was significantly lower (pƒ¬0.05) than untreated sliced tomatoes. No significant differences (p>0.05) were found in Hunter L, a, or b values between untreated tomato slices or slices treated for 135 minutes. Aerobic plate counts of spoilage microorganisms treated with gaseous ozone for times of 105, 120, and 135 minutes were significantly lower than untreated samples but samples treated for 90 minutes were not statistically different from untreated samples. Results indicate that gaseous ozone treatments that are effective in decreasing spoilage microflora of sliced tomatoes did not adversely affect Lycopene and color measurements. However ascorbic acid content of the tomato slices was significantly reduced by the minimum ozonation treatment necessary to reduce spoilage microbial counts.
Session 104C, Fruit & Vegetable Products: Vegetables (Processed)
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