INFLUENCE OF FRUIT DEVELOPMENTAL AND MATURITY STAGES ON CHEMICAL, PHYTOCHEMICAL AND ANTIOXIDANT PROPERTIES OF POMEGRANATE JUICE
Pomegranate fruit (Punica granatum) is commercially cultivated in many tropical and subtropical regions due to its nutritious and beneficial health properties. This study was undertaken to investigate the influence of fruit developmental and maturity stages on the major chemical and phytochemical composition of pomegranate juice (PJ) (Bhagwa). At 54, 82, 110, 140 and 165 days after full bloom (DAFB), fruit pH, total soluble solids (TSS), individual sugars, titratable acidity (TA), organic acids and ascorbic acid (AA) contents were measured. Total phenolics content (TPC), total flavonoids (TF), gallotannin (GT), total anthocyanins and individual anthocyanins were also measured. Total antioxidant capacity (TAC) of fruit juice was assessed by the free radical scavenging ability (DPPH) and ferric reducing antioxidant power (FRAP) assays. The results showed significant (P<0.05) increases during fruit maturity in TSS, fructose, glucose, ascorbic acid and total anthocyanins, and significant decreases in TA, organic acids and total phenolic content (TPC). The observed increase in TSS/TA ratio which plays a important role in juice flavour peaked significantly (P<0.05) at 140 DAFB, while the highest anthocyanins content occurred at the full-ripe stage (165 DAFB). Antioxidant capacity (both DPPH and FRAP) decreased during fruit maturation, and a strong correlation was observed between TPC and antioxidant capacity measured as DPPH (r=0.96) and FRAP (r=0.95) respectively. Overall, the results showed that the phenological development of Bhagwa pomegranate fruit is characterised by well-differentiated changes in chemical and antioxidant properties. The observed changes in the investigated compounds suggest that sugars, organic acids, anthocyanins and AA as well as TPC concentrations may be considered as potential indices for assessing readiness to harvest of Bhagwa pomegranate fruit. The results also provide information that could assist growers and pomegranate juice producers to optimize fruit juice quality and its medicinal value.
Fawole, O.A., Opara, U.L. and Theron, K.I. (2013). INFLUENCE OF FRUIT DEVELOPMENTAL AND MATURITY STAGES ON CHEMICAL, PHYTOCHEMICAL AND ANTIOXIDANT PROPERTIES OF POMEGRANATE JUICE . Acta Hortic. 1007, 461-469
sugars, anthocyanins, total antioxidant capacity