Journal of Food Processing & Technology

Abstract

Effects of Pre-Heating and Concentration Temperatures on Physico-Chemical Quality of Semi Concentrated Tomato (Solanum lycopersicum) Paste

Yassin Hassen, Habtamu Gebre and Abebe Haile

Fresh tomato is one of the fruits with a short shelf life. The purpose of this study was to evaluate the effects of pre-heating and concentration temperatures on the physicochemical and microbiological quality attributes of semi-concentrated tomato paste. Breaking temperatures of 60°C, 70°C and 90°C for 7 min and concentration temperatures of 80°C and 90°C were used to prepare semi tomato paste of 13-degree Brix of Total Soluble Solids (TSS). TSS, titratable acidity, pH, lycopene, vitamin C, viscosity were determined following standard methods. Increasing breaking temperature and concentration temperatures significantly (p<0.05) increased TSS, viscosity, and lycopene content, but reduced significantly (p<0.05) vitamin C content. The hot broken tomato at 90°C and concentrated at 90°C caused a significant reduction of vitamin C content (44% loss) as compared to the other treatments of tomato paste samples but greater product consistency (gross viscosity) and higher lycopene content. Processing conditions have a great influence on the overall quality of the final product. The breaking process at 70°C and concentrating at 80°C shown good viscosity and better retention of vitamin C. Therefore, breaking at 70°C and concentrating at 80°C can be adopted for commercial production of tomato paste.