Effect of Chemical Additives on the Shelf Life of Tomato Juice
Tomato (Lycopersicon esculentum Mill.) is one of the most popular and demanding vegetables grown in Bangladesh. The aim of this study was to assess the effect of chemical additives on the shelf life of tomato juice. Tomato juice was prepared with three different chemical additives namely Potassium meta-bisulphate (KMS), Sodium benzoate and sorbic acid. The shelf life of these tomato juices was studied for 60 days storage period. Chemical analysis and sensory tests were carried out during the 60 days at an interval of 15 days to assess the effect of chemical additives on the shelf life of tomato juice. Negligible change in chemical constituents except vitamin C was observed in the prepared juices throughout the 60 days storage period. Color was gradually faded and off-flavor developed at the end of the storage time at room temperature. Additives and storage period has significant effect on percent acidity. Tomato juice prepared with potassium meta bisulphate was spoiled after 45 days whereas, tomato juice prepared with sorbic acid was spoiled after 30 days of storage at room temperature. Tomato juice prepared with sodium benzoate was more stable than others and spoiled at the end of the 60 days storage period at room temperature. Total number of viable bacteria was highest in tomato juice with potassium meta bisulphate and tomato juice with sodium benzoate contained least viable bacteria. There were no significant difference among the juices with three different chemical additives in respect to color and acceptability. Considering all the parameters, sodium benzoate tends to be better additive than potassium meta bisulphate and sorbic acid for preservation of tomato juice.