Optimizing Ingredient levels for the production of Eshabwe, a milk-based sauce from western Uganda.

Abstract

Eshabwe, is a traditional condiment derived from ripened butter or ghee. Its processing involves use of varying recipes and unstandardized raw materials thus posing potential health risks to consumers. To enhance its safety, stability, and quality, this study employed response surface methodology with Design Expert software to optimize ingredient levels and processing conditions. The key independent variables for optimization were: rock salt (0 – 25 g), water (0 – 903 mL), and iodised table salt (0 – 14 g), per 1000 g of pasteurized cultured butter. The optimal ingredient levels were determined as: 19.9 g rock salt, 720 mL water, 3.7 g iodised table salt, and 1000 g butter. These optimal levels resulted in the following response variables: density (0.8 g/ml), oil separation (0.9 ml), mixing time (17.2 min), moisture content (42.5%), and acceptability scores of different attributes ranging from 6 (like slightly) to 7 (like moderately). There was strong relationship between the response and independent variables (R2 > 81%). The resultant Eshabwe formulation contained 45.1±0.3% moisture, 1.1±0.1% ash, 0.4±0.4% crude protein, 43.8±0.3% fat, 9.6±0.4% total carbohydrate, and 433.9±0.5 Kcal/100g, with notable mineral levels such as 22.1±0.3 mg/100g calcium and 1284.3±0.1 mg/100g sodium. Titratable acidity, pH, milk solids not fat, viscosity and water activity (aw) were 0.4±0.0%, 8.2±0.0, 11.1±0.6% ,7166±5.3 cP and 0.98±0.0, respectively. Eshabwe produced from pasteurized cultured butter had a total plate count of 3.0±0.0 log cfu/g and no detectable coliforms, and fungi. Addition of 1% monoglyceride, 0.01% BHT and 0.1% potassium sorbate to Eshabwe, resulted in stable Eshabwe with no oil separation and the product remained acceptable up to two weeks at room temperature (23-28°C) and more than eight weeks when stored in the refrigerator at 2-4°C. Furthermore, 45 g of optimized Eshabwe contributed 39.4 – 117.9%, 17.1 – 23.1%, 6.5 – 15.0%, 1.3 – 4.0% and 0.3 – 0.9% of the daily recommended requirement for fat, sodium, energy, calcium and protein for children and adults of all age groups. The formulation developed in this study can, therefore, be adopted for commercial production of acceptable and safe Eshabwe with a consistent quality. Key words: Eshabwe, optimization, cultured butter, shelf stability, antioxidant, emulsifier