Effect of stabilizer on drying characteristics and quality of mango soy fortified yoghurt

Mango soy fortified yoghurt (MSFY) samples were prepared in the laboratory using the optimized blend formulation. Stabilizers were added during preparation of MSFY, which was then dried in a recirculatory convective dryer in 4-mm-thick forms using hot air at 50 °C and an air velocity of 2.5 m/s with 80% air recirculation. The starter counts, acetaldehyde retention, colour change and dispersibility of the dried control (MSFY) as well as MSFY containing stabilizers were determined. The effects of the amount (0.2, 0.4 and 0.6 g/100 g MSFY blend) and type (gelatin, pectin and sodium alginate) of stabilizers on drying characteristics of MSFY were studied. An increase in the level of the stabilizer in MSFY increased the drying rate. The effective moisture diffusivity increased with the increase in the amount of stabilizer added. The addition of gelatin and pectin to MSFY improved starter culture counts after drying, while the addition of sodium alginate had a negative effect. The addition of stabilizers improved acetaldehyde retention in the samples in all cases. An increase in stabilizer addition rate, increased the change in colour. Most of the MSFY samples with stabilizer had better dispersibility than those without stabilizer.