Production of Antioxidant Rich Tomato Vinegar: An Alternative to Coconut Vinegar in Culinary Production

Abstract

Tomato is an antioxidant-rich highly perishable fruit, and it is a crop with high postharvest losses due to its tender appearance and surplus production. Thus, to allow value addition and to reduce its postharvest losses, tomato vinegar, a novel type of vinegar to Sri Lanka was developed. During the study, locally available tomato was utilized as the major raw material, and tomato pulp with 10.7°Brix was prepared. Alcoholic and acetous fermentation was performed using Baker’s yeast and Acetobacter pasteurianus PP21 respectively, at 30 and 36°C. Total acidity, total sugar content, total soluble solids, alcohol content, total phenols, total antioxidant activity (EC50 value), and total flavonoid contents of the developed tomato vinegar were examined, and the results were compared with those of commercially available coconut vinegar. The results revealed that the total acetic acid content of vinegar produced at 30 and 36°C was 5.139±0.145 (w/v) and 4.12±0.32 (w/v), respectively. The EC50 value of the tomato vinegar produced at 36°C (13.87±0.63) was found to be significantly lower than that of commercial coconut vinegar (101.5±1.66), indicating a high antioxidant activity. Moreover, compared to coconut vinegar, a higher phenolic content, 365.020±5.53 mg GAE/l, was found in the developed tomato vinegar. The results of the sensory evaluation revealed that the developed tomato vinegar was significantly better than the commercial coconut vinegar, either as its raw form or as used in the production of Sri Lankan traditional dishes. Thus, the developed tomato vinegar is a good alternative to coconut vinegar in Sri Lankan cuisine.