Fresh pomegranate juices from cultivars and local ecotypes grown in southeastern Italy: comparison of physicochemical properties, antioxidant activity and bioactive compounds

Abstract

Background: Pomegranate juice has gained attention for its health properties, becoming consequently a highly demanded product. The revival of the pomegranate in Italy, as in other Mediterranean countries, starts with the planting of new intensive orchards characterized by both the new cultivation technique and new varieties. As a result of growing demand and high productivity, pomegranate could become an interesting crop to diversify farm income. This study seeks to determine the aril juice quality attributes and bioactive compounds of six pomegranate cultivars ('Mollar', 'Dente di cavallo', 'Acco', 'Jolly red', 'Wonderful' and 'Wonderful Super') and two local ecotypes ('Eco BA' and 'Eco FG') grown in Apulia region, southern Italy.

Results: The aril juices were evaluated for their main physicochemical properties (yield, color, pH, total soluble solids content, titratable acidity, sugar-acid ratio), chemical and bioactive compounds (vitamin C, phenolics, anthocyanins and antioxidant activities). 'Eco BA', 'Mollar' and 'Jolly red' genotypes were characterized by the highest maturity index, and then could be considered to be sweet-sour in taste. Total phenols and antioxidant activity were higher in 'Dente di cavallo' and 'Eco FG' genotypes. 'Eco FG' was also the richest in vitamin C, punicalagin and ellagic acids, while 'Dente di cavallo', 'Acco' and 'Wonderful' showed the highest content of the detected anthocyanin compounds.

Conclusion: These results contribute to current knowledge about chemical composition, phenolic contents, anthocyanin profiles and antioxidant activity of pomegranate juice from different genotypes, showing in most cases an appreciable juice quality and bioactive profile, although significant differences among them were detected. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Keywords: anthocyanins; antioxidant activity; juice quality; physicochemical properties; polyphenols; pomegranate genotypes.

Figure 1

Antioxidant activity (line) and total phenol content (bars) of juice from pomegranate genotypes. Different letters (upper‐ and lower‐case letters refer to total phenol content and antioxidant activity, respectively) indicate statistical differences at P < 0.05.

Figure 2

Vitamin C of pomegranate juice from different genotypes. Different letters indicate statistical differences at P < 0.05.

Figure 3

Principal component analysis bi‐plot (PC1 vs. PC2), showing the spatial distribution of the pomegranate genotypes (top) and of the whole dataset (bottom).