Nutritional and total phenolic analyses of unfermented and fermented red grape (Vitis vinifera) beverages

Grape juices-fresh, homemade fermented and commercial non-alcoholic were evaluated for their nutritional, Physico-chemical, phenolic and anthocyanin content. The grape juices obtained were clear, purple, and pH ranging between 3.3-3.5. The titrable acidity increased in the commercial grape juice (8.65%) whereas total solids (22.67%) was higher in the homemade fermented samples. The nutritional parameters such as carbohydrate, protein, dietary fibres etc. increased in the commercial sample except for vitamin C, which was higher in the fresh juice sample. The total phenolic content (2650 mg/lit) and total anthocyanin content (310 mg/lit) of commercial grape juice was higher compared to the homemade fermented sample. The increase in various parameters in the commercial sample could be attributed to manufacturing and processing techniques used during the production of grape juice.