The effects of various stabilizers on physiochemical properties of camel's milk yoghurt

The effect of stabilizers addition on physicochemical and organoleptic properties of yoghurt made from camel milk was studied. Three stabilizers were used, A (gelatin E441, mono & diglyceride of fatty acids E471), B (guar gum E412, sodium carboxymethyl cellulose E466 and mono & diglyceride of fatty acids E471) and C (modified starch E1422 and mono and diglyceride of fatty acids E471). The addition rate of stabilizers to camel milk was 0.5%, 1.0% and 1.5%, w/w. The products were stored at 5±2°C for 21 days. Addition of stabilizers significantly decreased the syneresis, and increased viscosity and water holding capacity of camel milk yoghurt (p ≤ 0.05), also enhanced their sensory acceptability. Significant effects of stabilizers type and addition rate on acidity, moisture content and total solids of camel milk yoghurt were observed. The water holding capacity and susceptibility to syneresis of camel milk yoghurt were significantly affected by type and quantity of stabilizer used. The optimum results were recorded using stabilizers A, B and C in order. Increasing the amount of the stabilizer added, resulted in water holding capacity and lower susceptibility to syneresis values. Acidity and pH values of camel milk yoghurt were significantly affected by type of stabilizer. Addition of stabilizers caused the highest acidity and the lowest pH of camel milk yoghurt compared to control. The stabilizers treated camel milk yoghurt had higher total solid, protein and fat than the control. Camel milk yoghurt containing stabilizer had higher viscosity than the control samples. The images of scanning electron microscope showed that the stabilizers occupied the void space within casein particle network. Treated camel milk yoghurts had more systematically and smoothly distributed proteins with a bit coarse structure as well as less porosity in protein network. As well as the addition of stabilizers to camel milk yoghurt to the merger of casein micelles with each other, which increases the cohesion flat casein compared with a control sample. The treatment B which retained the highest rate of water holding capacity had colloidal or ropiness texture, while cohesion textures increased in both treatments A and B. Adding stabilizer A (gelatin E441, mono & digilycerid of fatty acids E471) at a level up to 1.5%, to camel milk yoghurt is recommended to stabilize the texture without affecting the overall acceptability of the product. (Alaa H. Ibrahim and Salah A. Khalifa. The effects of various stabilizers on physiochemical properties of camel milk yoghurt. J Am Sci 2015;11(1):15-24). (ISSN: 1545-1003). http://www.jofamericanscience.org. 3