Physiochemical and phytochemical profile of unripe black grape juice (verjuice)

Abstract

This study investigates the physicochemical, phytochemical, and mineral properties of juices are known as verjuice obtained from unripe black grapes. Moisture, pH, total soluble solids (°Brix), total titratable acidity, crude fibre and vitamin C (ascorbic acid) were found to be 74.6%, 2.3,5, 3%, 4.5% and 15mg/100ml, respectively. Organic acid content (tartaric and malic) was determined as15.2 and 7.4 mg/ml, respectively, and total phenol content was 307 mg/l. Total antioxidant capacity was found to be 36 μg/ml (Gallic acid), determined using a DPPH (2, 2-diphenyl-1-picrylhydrazyl) assay and total anthocyanin content was 23.43 mg/l. Unripe grapes are relevant for use as an acidifying agent for extending the shelf life of foods.