Effect of pH and Temperature on Antioxidant Levels of Tomato Wine

Abstract

Tomato wine antioxidant properties were studied. The wine was produced using tomato musts of different pH levels, which was fermented at 15 and 20C using Saccharomyces bayanus, 818. The wines produced with musts of pH levels 4.11, 3.40 and 3.20 were designated as C (Control), A and B, respectively. The total antioxidant activity (TAA) of the tomato wines was higher (P < 0.05) than the tomato juice. The TAA of the wines produced at 20C was higher (P < 0.05) than those at 15C; also, C at 20C recorded higher TAA (P < 0.05) and best antioxidant properties than the rest. The TAA of the tomato wine was significantly correlated with total phenolics (R = 0.851, P < 0.01), total flavonoid (R = 0.738, P < 0.01), anthocyanin (R = 0.613, P < 0.01), 1, 1-diphenyl-2-picryl-hydrazil (DPPH) (R = 0.567, P < 0.05) and ascorbic acid (0.555, P < 0.05). DPPH scavenging activity was significantly correlated with ascorbic acid (R = 0.903, P < 0.01), total phenolics (R = 0.780, P < 0.01) and anthocyanin (R = 0.631, P < 0.01). Practical Applications Processing influences the bioactive compound composition and hence the antioxidant activity of the processed food. The study has shown that wine made from tomato contains bioactive compounds and exhibit varied levels of antioxidant activity based on the processing conditions. The bioactive compound composition and the total antioxidant activity of the tomato wine were found to be higher than the tomato juice, thus making the former more useful in terms of potential health benefits. The research is useful because it has identified the wine-making conditions which can help to produce tomato wine having the best antioxidant properties. In addition, the study has established the fact that making wine from tomato gives a product of better antioxidant properties than making juice from it.