Optimization of coating formulation containing spinach for puffed corn snack

The aim of this study was to optimize the formulation of coating of bulked corn products using maltodextrin, corn and spinach in order to improve the nutritional characteristics of puffed snacks. oil (55-65%) and powder materials (35-45%) as fixed components (80%) including milk powder, whey powder and salt (25, 50 and 5%, respectively) – and variable components (20%) including cheese powder, maltodextrin and corn starch were used to prepare the coating. Optimization was done with cross statistical design. After the physicochemical and sensory tests and selecting the optimal sample, spinach powder was added to the optimal formulation at 4, 6, and 8%, and sensory tests and uniformity evaluation were performed. The results showed that the oil absorption, hardness, redness, colloidal stability and sensory characteristics of the sample was increased by use of corn starch in the coating formulation, but overall acceptance was reduced, while redness and sensory characteristics increased by use of maltodextrin and oil absorption and hardness was reduced. The oil absorption, hardness, colloidal stability and flavor increased by use of cheese powder in the coating and redness and sensory characteristics reduced. Increasing the percentage of oil to 63% increased oil absorption and decreased the redness index (p<0.05). Increasing the percentage of oil to 60% significantly increased texture hardness, colloidal stability and color factor (p<0.05). The best optimal coating containing 10% each maltodextrin and cheese powder and 55% oil was obtained. The scores of sensory factors in the formulation containing 8% spinach powder were significantly higher than the others (p<0.05) and adding 8% of spinach powder to the optimal coating was recognized as the best sample. The results showed that in order to improve the uniformity and stability of the coating emulsion, maltodextrin and corn starch can be used and its nutritional value can be increased by using spinach.