Phytochemicals, Antioxidant Activity and Identification of Phenolic Compounds by HPLC of Pomegranate (Punica granatum L.) Peel Extracts

Abstract

Pomegranate peel is food waste unfit to eat parts obtained during the production of pomegranate juice. The aim of this work is to study the effect of four different solvents (ethanol, isopropanol, hot and cold water) on phytochemicals screening, total phenolics content, total flavonoid content and antioxidants activity in pomegranate peels, as well as identification of phenolic compounds in extracts by HPLC. Phenolics, flavonoids, alkaloids, saponins, tannins, steroids and terpenoids were detected in all extracts. The highest total phenolics and total flavonoids were observed in ethanol extract of pomegranate peels (161.5 mg GAE/g and 70.65 mg Rutin/g), respectively. Furthermore, the ethanol extract of pomegranate peels showed the highest DPPH scavenging activity with the lowest IC50 value 14.6 μg/ml compared to other extracts. The high antioxidant activities may be due to the high contents of phenolics and flavonoids in pomegranate peel ethanol extract. HPLC analysis was used for the identification and quantitative determination of phenolic compounds in pomegranate peels extracts. The results revealed nine polyphenolic compounds including protocatechuic acid, p-coumaric acid, caffeic acid, ellagic acid, cinnamic acid, quinic acid, benzoic acid, syringic acid and iso-ferulic acid in pomegranate peels extracts. The obtained results confirmed that ethanol extract was the most abundant of phenolics compounds as compared to the other extracts. Finally, it can be concluded that pomegranate peel extracts can be used in various fields for being rich in natural antioxidants that have a medicinal and therapeutic impact.

Chemical Fingerprinting, Antioxidant, and Anti-Inflammatory Potential of Hydroethanolic Extract of Trigonella foenum-graecum

“…The most abundant antioxidant and antimicrobial compound found was p-coumaric acid with a concentration of 256.7 ± 6.8 g/100 g of DE followed by ferulic acid 168.4 ± 1.8 g/100 g of DE. The results were in agreement with previous reports by [ 47 , 48 ], who reported the abundance of p-coumaric acid in plant extracts. The identification of phytochemicals indicates that antioxidant and other biological properties of extract could be due to the presence of these bioactive compounds.…”

Pomegranate Peel Phytochemistry, Pharmacological Properties, Methods of Extraction, and Its Application: A Comprehensive Review

“…Gallo tannins, ellagic acid, punicalins, punicalagins, and gallic acid are some of the major phytochemicals present in pomegranate peel, as shown in Figure 1 . 15 El-Hamamsy and El-khamissi 16 revealed that pomegranate peel extract (PPE) is rich in several phytochemicals, including tannins, steroids, phenolics, alkaloids, flavonoids, terpenoids, and saponins. Nine polyphenolic constituents, including p -coumaric acid, syringic acid, benzoic acid, ellagic acid, caffeic acid, cinnamic acid, protocatechuic acid, isoferulic acid, and quinic acid, were identified and quantified in the extracts using HPLC.…”

Nutritional importance and industrial uses of pomegranate peel: A critical review

“…Every day, PoPs are used in various food varieties owing to their great nutritional and chemical composition (Kandylis & Kokkinomagoulos, 2020 ). PoP contains high levels of carbohydrates (59.60%) followed by moisture content (5.40%–5.95%), protein content (4.90%–8.97%), ash content (3.40%–4.22%), fiber content (16.30%–19.41%), and fat content (0.85%–1.26%) (El‐Hamamsy & El‐khamissi, 2020 ; Khan et al, 2017 ). The chemical and nutritional composition of PoP were presented in Table 1 .…”