Determination Of Biologically Active Substances And Natural Antioxidants In The Juice Of Two Local Pomegranate Fruits

This study was conducted in the laboratories of Tikrit University / College of Agriculture / Department of Food Sciences, and it aimed to study the effect of some chemical and physical characteristics, activity, concentrations and stability of antioxidants present in sweet and sweet-sour pomegranate juice, as well as determining the proportions of phenolic compounds, sugars, vitamins and ascorbic acid concentration. The results showed a higher moisture content for sweet pomegranate juice, and a lower percentage of total soluble solids (TSS) for sweet pomegranate juice compared to sweet-sour pomegranate juice. Sweet pomegranate juice also recorded a significant increase in total sugars content and PH. sweet-sour had the highest value in citric acid, while sweet-sour pomegranate juice recorded the highest value in electrical conductivity (EC) which amounted to 3481, as well as a high level in density (1.101) g/ml. Whereas sweet-sour pomegranate juice gave the lowest viscosity value, which was 1.65 centipoise, and there was a discrepancy in the vitamin content, where vitamin B9 recorded the highest content in sweet pomegranate juice with a value of 23.35 mg/100 ml, followed by vitamin B2, then vitamin B6, and finally vitamin B12 with a value of 5.30 mg /100 ml, and sweet pomegranate juice gave the highest value in anthocyanin pigment content, as well as the highest content in the total phenolic compounds, reaching 30.65 mg/100 ml and 54.20 mg/100 ml respectively. and when cold storage for a period of 6 weeks, no significant differences were observed in the values of TSS and PH values for both juices in the first and second weeks, while the differences appeared clear at the beginning of the third week, and sweet-sour pomegranate juice recorded a noticeable decrease in the value of PH at the fourth and fifth weeks, and this decrease was most severe at the fifth week for both juices, especially in sweet-sour pomegranate juice.