Effect of tomato cultivars, honey finisher and processing methods on quality of tomato ketchup
The experiment was carried out using factorial combination of two tomato varieties, two processing methods and three honey and one sugar concentrations with three replications. Tomato ketchups prepared from Melkashola subjected to pre-heat treatment before cooking exhibited higher total soluble solids, reducing and total sugars, as well as lower microbiological load. However, heat treatment significantly influenced the color of ketchups. Variety and processing methods significantly (P ≤ 0.01) affected the physico-chemical, microbiological and sensory qualities of the ketchup. Also, honey concentration treatment improved the quality of ketchup. Addition of honey at 500 ml level resulted in higher reducing sugar, total sugar, titratable acidity and total soluble solids content. However, this treatment led to lower moisture content, pH and microbial activity of tomato ketchup. The interaction between variety and processing methods combined with honey concentration treatments were significant at P < 0.01 level. Similarly, the combined effect of variety, processing method and honey concentration resulted in higher moisture content, pH and reduction in microbial population, while it maintained higher total soluble solid, total sugar, reducing sugar, titratable acidity and ascorbic acid of the ketchups. Ketchups manufactured from fresh juice of Marglobe and Melkashola had good color. The taste and flavor of ketchups that received high concentration of honey had higher score when compared to the control without honey.
Keywords: Cultivars, honey finisher, fresh juice, blanched juice.