Antioxidant activity evaluation and HPLC‐photodiode array/MS polyphenols analysis of pomegranate juice from selected italian cultivars: A comparative study

Abstract

Chemical composition of pomegranate juice can vary due to cultivar, area of cultivation, ripening, climate, and other variables. This study investigates the polyphenolic composition and antioxidant activity of juices obtained from six old Italian pomegranate cultivars. Fruit accessions physicochemical characteristics were determined. Total polyphenols content (TPC), anthocyanin content (TAC) and proanthocyanidin content (TPAC) were measured in the juice samples. Phenolic bioactive molecules were analyzed by HPLC-photodiode array (PDA)/ESI-MS in all the pomegranate juices. In total, seven nonanthocyanidinic and six anthocyanidinic compounds were identified. The six anthocyanins were found in all juices although at different amounts. These results were correlated with antioxidant activity measured by three different chemical assays: 2,2 diphenyl-1-picrylhydrazyl (DPPH(•) ) scavenging activity assay, Trolox equivalent antioxidant capacity (TEAC) method and ferric reducing-antioxidant power (FRAP) assay. Pomegranate juices obtained by six different varieties show variable polyphenolic content and antioxidant activity. The antioxidant capacity methods used have shown variable sensitivity, supporting the hypothesis that different methods for the assessment of antioxidant capacity of food compounds are indeed necessary, due to complexity of sample composition and assay chemical mechanism and sensitivity. Juices from Italian pomegranate show good levels of polyphenols content and antioxidant activity making them potential candidates for employment in the food industry.

Effect of Cocoa Polyphenolic Extract on Macrophage Polarization from Proinflammatory M1 to Anti‐Inflammatory M2 State

“…Total antioxidant capacity of cocoa extract was measured by using the Trolox equivalent antioxidant capacity (TEAC) assay [40]. Briefly, 10  μ l of cocoa polyphenolic extract was mixed with 200  μ l of ABTS + solution in a 96-well cell culture plate and the absorbance was recorded at 734 nm for 90 seconds by a multifunctional microplate reader (Infinite M 200 Pro, TECAN, Italy).…”

“…HPLC analyses, performed on 2  μ l of the injection volume, were carried out as previously described [40]. In particular, the mobile phase contained water (Sigma-Aldrich) /formic acid (Riedel-de Haën, Hanover, Germany) (99.9 : 0.1, ( v/v )) (solvent A) and acetonitrile (Sigma-Aldrich)/formic acid (99.9 : 0.1, ( v/v )) (solvent B), and the stepwise gradient profile was as follows: 0 minutes, 5% B; 30 minutes, 30% B; 35 minutes, 100% B; and 36 minutes, 0% B.…”

Anthocyanins from Pomegranate (Punica granatum L.) and Their Role in Antioxidant Capacities in Vitro

“…The cultivar genotype is the main factor responsible for the variability of pomegranate TAC. Numerous reported data have covered a large range of values for TAC both in peels and in juices [22,25,34,36,40,43,48,62–76] . For most cultivars, the quantitatively dominant anthocyanin components are Cy3G and Cy3,5dG, accounting for more than 85 % of total anthocyanins, [13,29,38,77] but there are often different descriptions in different cultivars.…”

“…[60] Indeed, antioxidant activities determined in various samples are influenced by several factors. Discrepancies with measured antioxidant activity in pomegranate may arise from cultivars, [22,51,63,68,69,89] extraction procedures, [27,51,56] and test system applied. [69,90] Of the variables, the chemical structure of anthocyanins and the in vitro detection protocols are important contributing factors determining anthocyanin antioxidant capacities.…”

The Effects of Salicylic Acid and Its Derivatives on Increasing Pomegranate Fruit Quality and Bioactive Compounds at Harvest and During Storage

“…Nevertheless, the phytochemical composition of pomegranate fruit is affected by several factors, such as genotype, area of cultivation, environmental conditions, and agronomic management, among others. Thus, six different anthocyanins, namely, cyanidin-3,5-diglucoside, pelargonidin-3,5-diglucoside, delphinidin-3,5-diglucoside, cyanidin-3-glucoside, pelargonidin-3-glucoside, and delphinidin-3-glucoside, were identified in a wide range of Italian pomegranate cultivars, although their concentrations were different depending on cultivars, as well as other phenolic compounds (Fanali et al, 2016;Russo et al, 2018). Great variations on total and individual phenolic and anthocyanin concentrations were also found by Zaouay et al (2012) in thirteen Tunisian cultivars.…”