
	American Journal of Food Technology
	Year: 2008 \| Volume: 3 \| Issue: 4 \| Page No.: 224-234 DOI: 10.3923/ajft.2008.224.234

Effects of Steaming and Dehydration on Anthocyanins, Antioxidant Activity,Total Phenols and Color Characteristics of Purple-Fleshed Sweet Potatoes(Ipomoea batatas)

J. Yang and R.L. Gadi

Abstract: Purple-Fleshed Sweet Potatoes (PFSP) (Ipomoea batatas) are rich sources of acylated anthocyanins. Anthocyanin content, antioxidant activity and total phenols as well as color characteristics of PFSP were determined by UV/visible or fluorescence spectrophotometry and chromametry. The flesh of PFSP cultivar Terlaje produced in the Western Pacific contained total anthocyanins at 0.40 mg g^-1 fresh weight. PFSP Powders processed by directly freeze-drying or first steaming and then freeze- or hot air-drying contained anthocyanins at 0.94-0.97 mg g^-1, Oxygen Radical Absorbance Capacity (ORAC) at 70.0-93.0 μmole Trolox g^-1, Trolox Equivalent Antioxidant Capacity (TEAC) at 11.8-12.7 μmole Trolox g^-1 and total phenols at 4-5 mg gallic acid g^-1 dry weight. PFSP powder processed by hot air-drying without steaming lost 65% of anthocyanin content, 35% of antioxidant activity and 40% of total phenols. Steaming of PFSP roots at atmosphere pressure for 0.5 h increased 40% of anthocyanin content and enhanced the purple color of PFSP. Dehydration at 60°C for 24 h retained anthocyanin content and purple color of steamed PFSP. Both steaming and dehydration increased the percentage of polymeric anthocyanins in PFSP. The results suggested the PFSP powders exhibited potentials as colorants and neutraceutical ingredients for formulated foods.

PDF Fulltext XML References Citation Report Citation

RELATED ARTICLES:

•	Effects of Deep-Fat Frying using Canola Oil, Soya Oil and Vegetable Oil on the Proximate, Vitamins and Mineral Contents of Unripe Plantain (Musa x paradisiaca)

•	Effect of Pre-drying, Blanching and Citric Acid Treatments on the Quality of Fried Sweet Potato Chips

•	Effect of Extraction Procedures, Genotypes and Screening Methods to Measure the Antioxidant Potential and Phenolic Content of Orange-fleshed Sweetpotatoes (Ipomoea batatas L.)

•	Impact of Three Cooking Methods (Steaming, Roasting on Charcoal and Frying) on the β-Carotene and Vitamin C Contents of Plantain and Sweet Potato

How to cite this article:

J. Yang and R.L. Gadi, 2008. Effects of Steaming and Dehydration on Anthocyanins, Antioxidant Activity,Total Phenols and Color Characteristics of Purple-Fleshed Sweet Potatoes(Ipomoea batatas). American Journal of Food Technology, 3: 224-234.

DOI: 10.3923/ajft.2008.224.234

URL: https://scialert.net/abstract/?doi=ajft.2008.224.234

COMMENT ON THIS PAPER

Navigation


		Online First
		Current Issue
		Previous Issues
		Editorial Board
		Submit a Manuscript
		Guide to Authors
		Subscribe to E-alerts

Indexed In


		ASCI-Database
		Asian Digital Library
		Cambridge Scientific Abstract
		Chemical Abstract Services
		FSTA
		Google Scholar

Science Alert