Bioactive compounds and quality evaluation of ‘Wonderful’ pomegranate fruit and juice as affected by deficit irrigation

Abstract

BACKGROUND: Persistent water shortage, typical of Mediterranean agricultural systems, has driven production methods towards the use of regulated deficit irrigation (DI) strategies, which may allow important water savings. To evaluate the extent to which pomegranate (cv. 'Wonderful') attributes may differ depending on the irrigation application rates, we investigated the effect of four different irrigation regimes (100, 75, 50, and 25% of maximum crop evapotranspiration-ET C) on their morphopomological, physico-chemical properties, and bioactive compounds. RESULTS: The weight and the size of whole fruits, and the number of arils and their weight per fruit, decreased significantly with the restriction of ET C water volumes applied to the crop. Minor differences were observed in soluble solids, pH, color of fruit skins, arils, and juices, although total acidity, maturity index, vitamin C, glucose, and fructose were not affected. However, total phenol content and antioxidant activity in juices were higher in the samples subjected to the DI treatments than in those submitted to full irrigation, showing the highest value at 50% ET C. A similar trend was found for anthocyanins delphinidin-3,5diglucoside and delphinidin-3-glucoside, reaching the highest concentration at 50% ET C. Among non-anthocyanin compounds, punicalagins and pedunculagin were more concentrated in the 75% ETc samples. CONCLUSION: The results of the present study indicate that the DI strategy throughout all the growing season is likely to have important implication for the pomegranate's physical, chemical, and phytochemical properties. Knowledge of them is useful in view of their processing and nutritional properties.

Analysis of the Phytochemical Composition of Pomegranate Fruit Juices, Peels and Kernels: A Comparative Study on Four Cultivars Grown in Southern Italy

“…[58] reported that vitamin C content in the pomegranate peel was significantly higher than in the aril, with differences ranging from 24.4% to 97.0%, depending on variety. Compared to our results, much lower levels of ascorbic acid were found in pomegranate juices from India (0.198 mg g −1 fw), Iran (0.09-0.40 mg g −1 fw), Poland (0.091-0.268 mg g −1 fw), and South Africa (0.168 mg g −1 fw) [23,40,59,60]. This discrepancy is possibly due to different agricultural practices and/or to the peculiar pedoclimatic conditions of southern Italy.…”

“…Much lower values were reported for Wonderful One (324-481 g) and Ako (151-350 g) cultivars grown in different Mediterranean countries, with a marked variability over the years [3]. A similar average weight (522.7 g) was, instead, found in Wonderful One pomegranate fruits grown in a commercial orchard in the north of Apulia (Foggia, Italy), with a gradual decrease in reduced irrigation regimes (down to 332.5 g at 25% of crop evapotranspiration) [23]. According to most authors, fruit weight is strongly affected by environmental conditions, cultivation practices, tree age, and total yield per tree.…”

Evaluation of Yeast Strains for Pomegranate Alcoholic Beverage Production: Effect on Physicochemical Characteristics, Antioxidant Activity, and Aroma Compounds

“…In the present study, no significant differences were observed between PAB and initial pomegranate juice. The initial acidity (16 g citric acid L −1 ) that was detected in the present study, it is the usual (15.4−17.5 g citric acid L −1 ) reported in juices of pomegranate cv Wonderful [ 27 , 29 ].…”

“…A crucial factor for all types of fermentation is pH because it affects the growth of yeasts and characteristics of the final product, such as color and taste. The pH range of pomegranate juice is 2.9–3.7 and varies according to different pomegranate variety [ 26 , 27 , 28 , 29 , 30 ]. In the present study, the pH value of the juice used was 3.12, which is similar with other studies with cv Wonderful, reporting the usual pH values between 2.9 and 3.2 [ 27 , 29 ].…”

Dynamics of the Fermentation Process and Chemical Profiling of Pomegranate (Punica granatum L.) Wines Obtained by Different Cultivar×Yeast Combinations

“…The determination of total phenol content (TPC) was performed by the Folin-Ciocalteu method according to Tarantino et al [15]. Twenty microliters of wine was added to 980 µL of ddH 2 O and 100 µL of Folin-Ciocalteu reagent.…”