Determination of antioxidant activity, total phenolics and mineral contents of some functional vegetable juice

Abstract

In this research, several vegetable and fruit pulp/concentrates were used in functional vegetable juice production. While producing vegetable juices, developing new tastes and increasing the nutritional quality and functional properties of the product was aimed. The recipes formulated by preliminary studies and six different kinds of vegetable juice were produced. Samples were pasteurized at 100 degrees C for 25 min and stored at room temperature for three months. Tomato, spinach, pumpkin, blood orange pulp/concentrates, raspberry, apple and black carrot juice concentrates were used as materials. After processing, total phenolics, antioxidant activity, minerals (Na, K, Ca, Mg, Fe), ascorbic acid, water-soluble dry matter (degrees brix), total dry matter, total acidity, pH and L*, a* and b* (colour) values were measured. Also sensory analyses were applied to the samples. Antioxidant activity (59.66 +/- 0.06 %) and total phenolics (1422.37 +/- 0.15 mg GAE/100 g) were found highest in the sample containing 100% vegetable/pulp juice. Also the same sample had the highest amounts of K, Mg and Na, while the sample containing 50% vegetable pulp/juice + 50% fruit juice had the highest Ca and Fe. Using different vegetable pulp and fruit juice concentrates which are rich in total phenolics, vitamins and minerals, that have high antioxidant capacity and pharmaceutical effects can be used for developing a functional beverage.