Impact of High Hydrostatic Pressure and Soaking Solutions on the Surface Structure, Carotenoids, Individuals' Phenolic Acids and Flavonoids Profile of Orange-Fleshed Sweet Potato Flour.

Abstract

The main objective of the current work was to monitor the impact of soaking solution (citric acid, calcium chloride and ascorbic acid) and high hydrostatic pressure (HHP) (100, 200 and 400 MPa) on the carotenoids, antioxidant activity (ORAC, Oxygen Radical Absorbance Capacity), surface structure, and individuals' phenolic acids and flavonoids of orange-fleshed sweet potato flour (OFSP). Carotenoids in OFSP increased several folds during treatment with ascorbic acid and HHP application at 400 MPa, whereas decreased contents were observed with the treatment of calcium chloride and citric acid. Ascorbic acid and 400 MPa significantly increased the phenolic acids (28.02, 27.40%) and flavonoids (8.45, 63.57%) respectively. The most abundant phenolic acid and flavonoid in OFSP were 3,5-di-O-caffeoylquinic acid and Quercitrin, respectively. Pearson correlation coefficient analysis was performed between ORAC and phenolic acids such as 5-Ocaffeoyl quinic acid (0.90), 4-O-caffeoyl quinic acid (0.89) and Myricetrin (0.86) which proved explicitly that antioxidant activity was mainly associated with these compounds. It was concluded that ascorbic acid and 400 MPa treatments of OFSP significantly impacted the increased levels of phenolic acids, flavonoids, and carotenoids. OFSP treated with ascorbic acid and 400 MPa might be used for multiple products with desired nutrients.