Antioxidant Activity of Tomato (Lycopersicon esculentum L.) of Low Soluble Solids and Development of a Shelf Stable Spread

Abstract

Tomato (Lycopersicon esculentum L.) is known to be associated with a reduced risk of developing a certain chronic diseases and cancers due to the presence of lycopene, a bioactive carotenoid. Commercially, the vegetable is used in the preparation of tomato puree or ketchup, but the local varieties with lower total soluble solids was found to be not useful for the same and fetching not enough prices during glut and being wasted without processing. In the present study, the local tomato variety (Heemsohna) with lower °brix and higher acidity grown in India was analysed for antioxidant activity. Its suitability for preparation of a value added novel product, 'spread' was evaluated by mixing tomato juice with sugar in the ratio of 1:1, 2:1 and 3:1 followed by concentrating the pulp to 65 °brix. The spread was analysed for physicochemical parameters and sensory acceptability during storage for six months. The methanolic extracts of dehydrated tomato exhibited a 50% inhibition in 2,2-Diphenyl-1-picrylhydrazyl radical scavenging activity and 2,2'-Azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) assay at a concentration of 5 and 2 mg/ml respectively. Variations in physicochemical properties of tomato spread such as °brix (64.5-65.0), pH (3.69-3.73), % acidity (0.69-0.74%), % reducing sugars (19.30-39.00%) % total sugars (56.95-60.21) and viscosity (2681-3255 cP) were measured. Significant changes were observed in sensory parameters such as colour, flavour and taste after 4 months however, the spread was well accepted by panelists with a maximum score of 6.9 for overall acceptability during the storage for six months. The study indicated that local varieties of tomato can be converted into a value added novel, highly acceptable and shelf stable spread which will help both farmers and consumers.