Effect of the addition of roselle (Hibiscus sabdariffa L.) extracts on the rheological, textural, and antioxidant activity of fermented milks

Abstract

AbstractThe study aims to evaluate the rheological, textural, and antioxidant activity of fermented milks with the addition of roselle (Hibiscus sabdariffa L.) extracts at concentrations of 0.0, 0.1, 0.2, and 0.3% (CFM, RFM1, RFM2, and RFM3). The chemical composition of the fermented milks, including crude protein, fat, ash, total solids and non‐fat solids, were also determined. Gas chromatography–mass spectroscopy (GC‐MS) detected 42, 46, 47, and 49 kinds of volatile flavour compounds in CFM, RFM1, RFM2, and RFM3, respectively. The antioxidant activity of fermented milks was measured using ferric reducing antioxidant power and scavenging capacities for 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and 2,2’‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulphonic acid) (ABTS) radicals during 28 days of refrigerated storage. The results of this study are of great significance to improve the understanding and application of roselle extracts in the food industry. Both roselle and fermented milk are beneficial to human health, with many biological activities, such as antioxidant, hypoglycaemic, liver‐protecting, and antihypertensive properties; however, no attention has been paid to the combined effects of roselle and fermented milks. The study created a novel fermented milk and the results indicate that 0.3% roselle extracts can play the most important role in affecting the rheological, textural properties, and antioxidant activity of fermented milks, so this modification of fermented milk shows promise for potential application in the food industry.