Formulation and quality assessment of tomato (Lycopersicon esculentum) cordial with xanthan stabilizer

Abstract

Tomato fruit is a nutritious part of the human diet providing a variety of health benefits. Searching for other means of utilization than direct consumption of tomatoes seems a timely need to reduce post-harvest losses caused by the rapid perishability of ripened tomatoes. In the present study, three tomato cordial formulations with xanthan gum as a stabilizer were tested for sensory properties, and the best formula was tested for its physico-chemical properties and stability over one month period. Well-ripened and healthy fruits were chosen to prepare the cordial. According to the Sri Lankan Standards (SLS 730), three different cordial samples were prepared only changing the concentration of xanthan gum stabilizer as 0.3%, 0.4% and 0.5% (w/v). Using 30 semi-trained panellists, prepared samples were subjected to sensory testing on a 5-point Hedonic scale, and 0.5% of xanthan gum containing cordial was selected as the best formula. The shelf-life evaluation of the best sample was conducted weekly for one month through physicochemical and microbiological analysis. Significant changes (p<0.05) were observed only in vitamin C content and total soluble solids (TSS) during the shelf-life evaluation. At end of the storage period, the cordial with 0.5% xanthan gum possessed pH 3.26, titratable acidity 1.35%, vitamin C 31.9 mg/100ml, TSS 44.9 °Brix, total sugar 19.8% and polyphenol content 0.0021 mg/ml GAE. Changes in the total plate counts during the one month of storage are within the acceptable limit (less than 50 per ml) according to the Sri Lankan Standards (SLS 516). It can be concluded that tomato cordial can be formulated by using 5% of xanthan gum stabilizer and that was found to be stable for one month without any deterioration.

Keywords: Preservation, physiochemical analysis, shelf-life, stabilizer, value addition.