30G-14 |
Antioxidant activity and colorant potential of extracts from pitahaya (Hylocereus undatus) fruit |
B. A. CEVALLOS-CASALS and L. A. Cisneros-Zevallos. Horticultural Sciences, Texas A&M University, Department of Horticultural Sciences MS 2133, College Station, TX 77843-2133 Natural plant colorants are in high demand by the food industry for replacing synthetic dyes such as FD&C Red #40 and the banned FD&C Red #2. This need arises from legislative action and consumer concern against synthetic food additives. Current commercial natural colorants have stability problems, generating a need to find stable colorants from novel natural sources. Our objective was to study the antioxidant activity and color potential of extracts from a highly pigmented pitahaya variety for promoting its use in natural colorant markets. Total phenolics, betacyanins, antioxidant activity and color were assayed spectrophotometrically. Color was also measured using a Minolta CIELAB colorimeter. Results indicate that pitahaya fruit has significant phenolic content and antioxidant activity. Initially, pitahaya pulp pigments maintain a red-purple hue from pH 1 to 11. At different time, temperature and light conditions, pHs 4, 5 and 6 showed the greatest stability. Addition of 1% ascorbic acid increased colorant stability. There was a significant regeneration of the pigment evaluated 31 hours after thermal processing at 98°C for different times. Addition of 1% ascorbic acid to a pH 5 extract increased pigment regeneration almost 3 times. Characterization of functional properties of novel crops opens the possibility to introduce new products into the market. The significant phenolic and betacyanin content of pitahaya seem to contribute to the functional properties tested on this novel crop, making it a healthier choice and an alternative for synthetic colorants.
Session 30G, Fruit & Vegetable Product: Processed Fruits and Vegetables
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