Determination of Water Soluble Vitamins in 15 Iranian Pomegranate Cultivars and Their Variation after Pasteurization and Cold Storage
The water-soluble vitamins (WSVs) of 15 pomegranate cultivars grown in Iran as well as their variations in fresh and heat-treated (90°C for 30 sec) juices were evaluated. The fresh and pasteurized juices of selected cultivars were stored respectively for 10 and 180 days at 4°C. The detected WSVs by HPLC-UV, in terms of quantity in the most of cultivars were ascorbic acid (10.4-35.4 mg/100 mL), pantothenic acid (114.9-301.5 μg/100 mL), thiamine (30.8-124.1 μg/100 mL), riboflavin (44.0-236.1 μg/100 mL), pyridoxine (12.0-90.3 μg/100 mL), and biotin (0.0-14.2 μg/100 mL). Significant reduction of WSVs in fresh (57.1-84.2%) and pasteurized (35.3-56.6) juices were observed at the end of storage period. The stability of ascorbic acid was lower than other WSVs in both fresh and pasteurized juices. Based on the results, WSVs are sensitive compounds that destroyed significantly during processing and storage, especially in unprocessed juice.