Antioxidant Potency of Red Dragon Fruit Flesh and Peel Prepared by Different Methods

Abstract

Background: Red dragon fruit (Hylocereus polyrhizus, (F.A.C. Weber) Britton & Rose) is widely consumed all over the world nowadays. The peel and flesh of red dragon fruit contain many bioactive compounds with high antioxidant activity. The preparation process is critical to maximizing the yield of the antioxidant content. Objective: The objectives of this research were to evaluate total phenolic content (TPC), total flavonoid content (TFC), as well as the antioxidant activity of peel and flesh of red dragon fruit prepared by various methods. Methods: The fresh and dried samples of peel and flesh of red dragon fruit were prepared via maceration and non-maceration process. Ethanol (96%) was used as the solvent in maceration. In the non-maceration process, the samples were ground using a blender and pressed using a juicer. TPC was analyzed by Folin-Ciocalteau methods, while TFC was determined by spectrophotometry UV-Vis with AlCl3. Antioxidant activity was analyzed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and β-carotene bleaching (BCB) tests. Results: Preparation methods affect the antioxidant activity of red dragon fruit peel and flesh. The highest TPC and antioxidant activity (BCB test) can be found in the ethanolic extract of the blended peel. Both the ethanolic extracts, blended peel and blended flesh, had the same DPPH radical scavenging activity. The highest TFC can be found in the ethanolic extract of dried-peel.

Fruit Peels: Food Waste as a Valuable Source of Bioactive Natural Products for Drug Discovery

“…It is well known that proanthocyanidins are produced by fruits, beans and nuts [92]. The proanthocyanidin dimers (−)-epicatechin gallate-(4β→8)-(−)-epicatechin (128), procyanidin B2 (129), have been reported from Pyrus pyrifolia (pear) fruit peels [93][94][95]. Pear fruit peels also produced cinnamtannins B1 (130), aesculitannin A ( 131) and (−)-epicatechin-(4β→6)-(−)-epicatechin-(4β→8, 2β→O→7)-(−)-epicatechin (132) [95] and these proanthocyanidin trimers displayed anticancer, antibacterial and antioxidative effects [96][97][98][99].…”

Red dragon (Hylocereus polyrhizus) fruit peel extract increased the motility and viability of spermatozoa of hypercholesterolemic rats (Rattus norvegicus)

“…Antioxidant compounds in red dragon fruit included phenols, flavonoids, phytoalbumin, and betalains such as betacyanin and betaxanthin (Harahap et al, 2020). Dragon fruit peel extract has better antioxidant activity than the fruit extract because of its higher phenolic content (Febrianti et al, 2020). The effect of red dragon (Hylocereus polyrhizus) fruit peel extract (RDFPE) on hypercholesterolemic male fertility subjects has never been studied.…”