30D-23 |
Effect of dehydration methods on carotenoids of carrot processing by-product |
Z. PAN, Department of Biological and Agricultural Engineering, University of California - Davis, One Shields Ave., Davis, CA 95616, J. Levic, and S. P. Shoemaker, California Institute of Food and Agriculture Research, University of California - Davis. In recent years the consumption of carrot related products has been increasing steadily due to the recognition of antioxidant and anticancer activities of beta-carotene in carrots. A large amount of processing by-products is generated and underutilized as low value products or wastes. It is important to find new uses for such carrot by-products. The objective of this study was to study the effect of dehydration methods on beta- and alpha-carotene contents in a carrot by-product and possibility of using the dehydrated product as a functional ingredient in feed. A carrot by-product containing primarily carrot skin from a commercial carrot processor was studied with a two-step dehydration process, press and drying. In the press step, samples were pressed at a room temperature (cold press) and 50°C (warm press). Pressed samples were then dried to the moisture content of about 14% at 50, 65 and 80°C in an air oven and a vacuum oven, respectively. The contents of beta- and alpha-carotene in the samples were measured at different stages with a HPLC method. The cold and warm presses reduced the beta-carotene by 3.1 and 6.4% and alpha-carotene by 3.4 and 7.6%, respectively. The moisture reductions in pressed samples with the two methods were not significantly different. The contents of beta- and alpha-carotenes in finished products decreased with the increase of drying temperature. The cold press plus vacuum drying gave the highest beta- and alpha-carotene contents among the treatments, but longest drying time. When the carrot by-product was cold-pressed and air-dried at 50°C, 87.2% and 89.2% of beta- and alpha-carotenes were remained in the finished product. The research results suggest that cold press plus air-drying at low temperature could be used to reduce the moisture content of carrot by-product. The dried product with high beta- and alpha-carotenes could be used as a functional ingredient in feed.
Session 30D, Food Engineering: Physical and chemical properties
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