Effects of extraction methods and heat treatment on total phenolic compounds and antioxidant activity in juice extracted from the Australian-grown 'wonderful' pomegranate

Physicochemical properties of the Australian-grown 'Wonderful' pomegranate juice (WPJ) including total phenolic compounds (TPC) and antioxidant activity (AA) were determined and compared with four different brands of imported pomegranate juices (IPJs). The TPC in WPJ was found to be 2,400 ± 200 mg/L gallic acid equivalent (GAE) while in the IPJs it ranged from 1,000 to 2,800 mg/L GAE. The AA of WPJ was 11.0 ± 1.0 mM/L Trolox equivalent antioxidant capacity (TEAC) while in IPJs it ranged from 5.5 to 14.5 mM/L TEAC. To facilitate consumer access to the health benefits of pomegranate, a probiotic product was developed from bovine milk supplemented with different levels of IPJ. Maximum IPJ supplementation level in heat-treated milk with no adverse effects on yogurt attributes was found to be 20% (V/V), resulting in maximum TPC level of 731 ± 69 mg/L GAE in probiotic yoghurt.