Chemical, antioxidant and sensory properties of tomato-watermelon-pineapple blends, and changes in their total antioxidant capacity during storage

A conductometric analysis of the effect of condensate of peroxides generated during lipid oxidation in an accelerated stability test was adapted to test the hypothesis that total antioxidant capacity of tomato products would sometimes increase during processing and in storage. Tomato pulp blends made from a mixture of tomato (Lycopersicon esculentum var Roma VF), watermelon (Citrullus vulgaris var Babylack) and pineapple (Ananas comosus var Smooth cayennes) were analysed for basic quality profiles of dry matter, Brix, titratable acidity (TTA) and pH, total reducing sugars, Component antioxidants phytochemicals and total antioxidant capacity. The lowest sensory score (overall impression) of 4.80 +/- 2.59 was recorded for tomato juice while, blend TWP 111p had highest score of 6.20 +/- 1.99. There was significant difference (P<0.05) in the basic quality profile of the pulp blends except for TTA values (0.37 +/- 0.02 to 0.45 +/- 0.05) and 2-Furfurals (2.47 +/- 0.03 to 2.71 +/- 0.01). The fresh blend of 50% tomato, 25% watermelon and 25% pineapple had the highest total antioxidant capacity of 3.69 +/- 0.52mg100mL-1 catechin equivalent. The total antioxidant capacity of the stored pulp increased from 2.95 +/- 0.13 to 6.22 +/- 0.32 mg100mL-1 catechin equivalent in pasteurised TWP 211p blend by 60days when stored at 40 degrees C. Total antioxidant status of tomato-based fruit mix increased during the first 80 days.