Extraction optimisation, hydrolysis, antioxidant properties and bioaccessibility of phenolic compounds in Natal plum fruit (Carissa Macrocarpa). (December 2021)

• Record Type: Journal Article
• Authors: Seke, Faith; Manhivi, Vimbainashe E.; Shoko, Tinotenda; Slabbert, Retha M.; Sultanbawa, Yasmina; Sivakumar, Dharini
• Is Part Of: Food bioscience. Volume 44:Part A(2021)
• Publication Date: 2021-12
• Subjects: Indigenous fruit -- Polyphenols -- In vitro digestion -- Antioxidant capacity -- Anthocyanins; Food -- Biotechnology -- Periodicals; Food -- Research -- Periodicals; Aliments -- Biotecnologia -- Revistes; Aliments -- Investigació -- Revistes; Food -- Biotechnology; Food -- Research; Revistes electròniques; Periodicals; 664.005
• DOI: 10.1016/j.fbio.2021.101425
• Languages: English
• ISSNs: 2212-4292

Abstract

Abstract: The phenolic content and antioxidant properties of fruits would be underestimated if the extraction method is not optimised and bound phenolic content are not considered. A Central Composite Design and Response Surface Methodology were used to optimize sonication time and ethanol concentration to obtain a food-grade phenolic extract from Natal plum fruit ( Carissa Macrocarpa ). The free and bound phenolics of Natal plum fruit were extracted, and their release was simulated by in vitro digestion. Optimal conditions (38% ethanol and 16.7 min of ultrasonication) yielded 863.99 mg kg -1 fresh weight of total phenolics and 421.52 mg kg -1 fresh weight of total anthocyanins. There were strong correlations between ferric reducing capacity to cyanidin 3-sambubioside (Cy-3-Sa) (R 2 = 0.948), and cyanidin 3-O-glucoside (Cy-3-G) (R 2 = 0.901). Compared to alkaline hydrolysis, acid hydrolysis produced more bound phenolic compounds. The optimum extract still had low anthocyanin bioaccessibility. The optimal extract of the Natal plum fruit may serve as a functional ingredient due to its high antioxidant capacity. Highlights: The Natal plum fruit (NP) ( Carissa Macrocarpa ) is native to Southern Africa. Ultrasonication with 38% ethanol for 16.7 min yielded higher total phenols. The acid hydrolysis of NP released more bound phenolic compounds. Anthocyanins are mostly degraded by protocatechuic acid in the intestine.