Determination of Physicochemical, Microbiological and Proximate Characteristics of Tomato Puree Produced for Domestic Use and Safe Consumption in Katsina State, Nigeria

Abstract

Tomatoes (Lycopersicum esculentum) are widely cultivated, consumed, and extremely surplus during harvest season in Katsina State, Nigeria. However, post-harvest losses of the surplus to spoilage are common due to the absence of adequate local preservation methods. This makes tomatoes scarce and unavailable for consumption for most of the year. This research focuses on domestic production of tomato purees from locally grown tomatoes as a means of enhancing preservation and non-stop supply, as well as analyzing their physicochemical, microbiological and proximate characteristics, in order to validate the quality, safety, stability, and nutritional values of the products. Production of two products – tomato puree and tomato mix followed standard processing methods recommended by US National Centre for Home Food Preservation. Physicochemical analysis results of tomato puree and mix, respectively, were pH 4.3:4.5, water activity (aw) 0.92:0.93, and total soluble solids (TSS) 11.60-11.:80, showing that both products met the national and international criteria for quality and stability of tomato products. Tomato’s mix had a higher water activity than tomato puree (0.93: 0.92). Microbiological analysis showed that the hygienic standard of the products met the criteria established by NAFDAC. Tomato puree and tomato mix, respectively, had 0.29 x 102:0.41×102 cfu/g for total bacterial count; 0.11 x 102: 0.70 x 102cfu/g for yeast andmold count, and zero count for Staphylococcus, E. coli, Salmonella and Clostridia, which satisfies the “zero tolerance’’ requirement set by both NAFDAC and Codex. This implies that both products will last for 12-18 months without refrigeration. Proximate analysis showed that tomato puree and tomato mix respectively, had moisture content of 84.03:75.33, carbohydrate 13.26:17.79 crude protein 1.05:2.72 crude fat 0.28: 0.33, crude ash 0.75:1.93 and fibre0.63:1.90, implying that the products are concentrated sources of macronutrients.Tomato mix however, had less moisture content and higher carbohydrates, crude protein and crude fiber, than tomato puree. It was recommended local processing of tomatoes should be encouraged, to improve availability and to reduce post- harvest losses in Katsina state, Nigeria.