Phytochemical Changes in Phenolics, Anthocyanins, Ascorbic Acid, and Carotenoids Associated with Sweetpotato Storage and Impacts on Bioactive Properties. Food Chemistry. E-Pub September 5, 2013. Mary H. Grace , Gad Yousef, Sally J. Gustafson, Van-Den Truong, G. Craig Yencho , Mary Ann Lila.
Plants for Human Health Institute, Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, NC Research Campus; USDA-ARS, SAA Food Science Research Unit, Department of Food, Bioprocessing, and Nutrition Sciences, North Carolina State University, Raleigh, NC; Department of Horticultural Science, North Carolina State University, Raleigh, NC 27695.
Sweetpotato phytochemical content was evaluated in four genotypes (NCPUR06-020, Covington, Yellow Covington, and NC07-847) at harvest and after curing/storage for 4 or 8 months. Curing and storage for up to 8 months did not significantly affect total phenolic content in Covington, Yellow Covington, and NC07-847, however for NCPUR06-020, a purple-fleshed selection, total phenolic content declined mainly due to anthocyanin degradation during storage. Covington had the highest carotenoid content at harvest time (281.9 μg/g DM), followed by NC07-847 (26.2 μg/g DM), and after 8 months, total carotenoids had increased by 25% and 50%, respectively. Antioxidant activity gradually declined during storage, and freshly harvested sweetpotatoes also demonstrated higher anti-inflammatory capacity as gauged by inhibition of lipopolysaccharide-induced reactive oxygen species (ROS) in SH-SY5Y cells. Gradual changes in sweetpotato phytochemical content and antioxidant and anti-inflammatory capacity were noted during normal long-term storage, but the specific effects were genotype-dependent.