104C-5 |
Effect of low dose gamma and electron beam irradiation on the quality characteristics of fresh cut green onions |
S. BUTRIS1, D. M. Foley2, F. Caporaso1, and A. Prakash3. (1) Food Science and Nutrition, Chapman University, One University Dr., Orange, CA 92866, (2) Biological Sciences, Chapman Univ., One University Dr., Orange, CA 92866, (3) Dept. of Food Science & Nutrition, Chapman Univ., 1 University Dr., Orange, CA 92866 As the demand for fresh cut vegetables has increased in recent years, ready-to-eat diced green onions have become popular, especially for food service. However, raw green onions contaminated with Shigella, cryptosporidium, and Hepatitis A have been implicated in food outbreaks. Irradiation is an effective process that can reduce the risk of food illness and possibly extend shelf-life of fresh cut vegetables. Our objective was to investigate the effect of low dose gamma and electron beam irradiation on the microbial safety and quality of fresh cut green onions. Samples of fresh cut green onions were treated with gamma and electron beam irradiation at 1 kGy. During the 14 d storage, changes in the microbial counts, as well as color and moisture loss were monitored. Sensory attributes were evaluated by a trained panel using a modified intensity scaling descriptive method. The dose uniformity ratio (Dmax/Dmin) was 1.4 for gamma irradiation (for a box of eight 1-lb bags) and 1.4 for electron beam irradiation for a single 1-lb bag of diced green onions. There were no significant differences in the quality of samples due to irradiation treatment. Irradiation reduced aerobic plate counts, yeast and mold, and psychrotrophic counts by 3-5 logs CFU/g. These differences were maintained through the 14 d storage. The non-irradiated control samples developed intense off aroma and softer texture due to enhanced microbial spoilage by day 14, while the irradiated green onions showed no significant changes in quality attributes (off aroma, off flavor, and texture). Irradiation is effective in reducing microbial load in fresh cut green onions without negatively affecting their quality. A two to five days extension in shelf-life due to irradiation is of significant value to the food service sector.
Session 104C, Fruit & Vegetable Products: Vegetables (Processed)
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