Characterization of chemical compositions and bioactive compounds in juices from pomegranates ('Wonderful', 'Chaca' and 'Codpa') at different maturity stages

Mariela Labbé1*, Pablo A. Ulloa2, Francisco López3, Carmen Sáenz1, Álvaro Peña1, and Fernando N. Salazar2
In recent years, pomegranate (Punica granatum L.) fruit has gained popularity due to its functional properties. In this study, the effects of maturity on the chemical composition (pH, acidity and total soluble solids), total phenolic contents, anthocyanin contents and antioxidant capacities of pomegranate juices from three varieties (Wonderful, Chaca and Codpa) were assessed. The fruits were collected manually at three maturity stages (M1: unripe, M2: medium ripe, and M3: full ripe) from the Region de Coquimbo (Chile). Pomegranate juice was obtained from squeezed arils of fresh fruit. Results showed that chemical composition did not significantly differ according to the variety or maturity stage. Phenolic contents decreased during the final stage (M3) for ‘Wonderful’ and ‘Codpa’ (8% and 29%, respectively, from M2). Six main anthocyanin compounds (cyanidin 3,5-diglucoside, delphinidin 3,5-diglucoside, pelargonidin 3,5-diglucoside, cyanidin 3-glucoside, delphinidin 3-glucoside, and pelargonidin 3-glucoside) were detected in the three varieties. Significant differences in the anthocyanin content and antioxidant capacity were determined among different varieties and maturity stages. ‘Codpa’ pomegranate juice can be considered a good potential source of anthocyanin compounds (total content 715 mg L-1) with a high antioxidant capacity (15.83 mmol Trolox L-1); the highest values for both parameters were observed in juice from fruits collected at the M2 stage. Principal component analysis allowed for differentiation of the pomegranate juices according to variety but not according to maturity stage.
Keywords: Anthocyanin profile, antioxidant capacity, maturity stages, phenol content, pomegranate juice, Punica granatum.
1Universidad de Chile, Facultad de Ciencias Agronómicas, Casilla 1004, Av. Santa Rosa 11315, Santiago, Chile.
*Corresponding author (m.labbe.pino@gmail.com).
2Pontificia Universidad Católica de Valparaíso, Facultad de Ciencias Agronómicas y de los Alimentos, Waddington 716, Valparaíso, Chile.
3Universitat Rovira i Virgili, Facultat d´Enologia, Av. Països Catalans 26, 43007, Tarragona, España.