Antioxidant properties and phenolic profile characterization by LC–MS/MS of selected Tunisian pomegranate peels

Abstract

Antioxidant contents and activities of different extracts from four Tunisian pomegranate peels, locally called "Acide", "Gabsi", "Nebli" and "Tounsi", were studied. Peels samples were extracted with three solvents (water, ethanol and acetone). For each extract, the total phenol contents and antioxidant activity were evaluated. The highest values of polyphenol, tannins, flavonoids and anthocyanins were recorded in the acetone extract of Acide ecotype with 304.6 mg gallic acid equivalent/g; 292.23 mg gallic acid equivalent/g; 15.46 mg Quercetin/g and 54.51 mg cy-3-glu/100 g, respectively. The acetone extract of Acide ecotype also showed the highest free radical-scavenging and reducing power activity compared to other extracts. Besides, the phytochemical analysis by LC-MS/MS revealed a high content of ellagitannins with punicalagin and punicalagin derivatives as the major compounds that might be responsible for promising antioxidant activity of pomegranate peel extracts. Two compounds (Castalagin derivative and Galloyl-bis-HHDP-hex derivative) were detected only in "Acide" ecotype in important contents.

Combined Effect of Spirulina Platensis and Punica Granatum Peel Extacts: Phytochemical Content and Antiphytophatogenic Activity

“…Levels of TPCs ranged between 4.59 and 131.14 mg GAE/g of dried sample ( Table 1). The best TPC (131.14 mg GAE/g of extract) was obtained from the S1 sample, consistent with previous studies [32], the TPCs of four ethanolic extracts from different Tunisian ecotypes ranged between 109.21 and 140.93 mg GAE/g. For S2 samples, results indicated the presence of TPC at a concentration of 4.59 mg GAE/g.…”

“…The total ash content of studied samples was between 5.02% and 10.69%, for S1 and S2 samples respectively. The concentration of ash found in pomegranate peels (S1) was higher than that reported by Abid et al [32], ranging between 3.71% and 4.97%, and lower than the values presented by Romelle et al [41]. As shown in the Table 1, Spirulina samples (S2) showed ash percentage of 10.69%; this value was comparable to A. platensis from Algeria and higher compared with previous work by Bensehaila et al [35].…”

“…For S1 sample, protein content was higher than those found in other Tunisian cultivars 'Acide' (3.96%), 'Nebli' (5.42%) and 'Tounsi' (5.84%) [32], as well as other Turkish cultivars, 'Lefon', 'Seedless', 'Kadi', 'Siyah' and 'Koycegiz', whose contents are 3.19; 3.11; 3.06; 2.67 and 2.58%, respectively [37]. The protein content in S3 sample (54.52%) was found to be higher (p < 0.05) than the other combined sample (S4: 37.42%).…”

“…Physicochemical composition of Spirulina and its combinations with pomegranate peel (S1-S4) is shown in Table 1 Moisture content of ethanolic extracts was measured as a percentage of water relative to dry weight. Moisture content of pomegranate peel from 'Gabsi' cultivar used in this study (S1) was about 74.25 ± 0.52% which is slightly higher than those found in other Tunisian cultivars: 'Acide', 'Nebli' and 'Tounsi', whose contents were respectively 67.26%; 72.58% and 72.68% [32]. As illustrated in Table 1, moisture content of sample S2 (Spirulina) was 8.25 ± 0.07%.…”

Valorization of byproducts from tropical fruits: Extraction methodologies, applications, environmental, and economic assessment: A review (Part 1: General overview of the byproducts, traditional biorefinery practices, and possible applications)

“…From a functional point of view, pomegranate fruit is characterized by a high antioxidant activity (Fu et al., ; Kim et al., ), due to high levels of phenolic compounds (Abid et al., ), as shown in Table . Nevertheless, the concentration of the individual compounds is significantly affected by the cultivar (Viyar et al., ).…”