Optimization of the microwave baking method and quality evaluation of a corn flour-based snack with added coconut flour byproduct

• Adding coconut byproduct in a microwaved corn-coconut snack is viable in a 20 %. • Power and time were the variables with major effect over color, aw and moisture. • Pre-gelatinization affects color, aw, moisture and cavities apparition in the snack. • Optimized snacks versions with and without salt had similar properties. • The similarity between snacks supports the feasibility of salt reduction. Microwave technology is commonly used to reduce cooking times in snack production by heating food through electromagnetic waves. However, this method can cause uneven heating, affecting moisture, water activity (aw), and color. When incorporating nontraditional ingredients like virgin coconut flour byproducts, and applying treatments such as ion addition (NaCl) or pre-gelatinization, it is essential to optimize processing conditions to ensure product quality. This study aimed to optimize snack formulation by evaluating microwave power, baking time, and the inclusion of coconut flour byproducts, and to evaluate the effects of pre-gelatinization and salt addition on aw, moisture content, instrumental color, and physical appearance. A central composite design (CCD) was used to determine the optimal formulation. Microwave power and baking time had significant linear effect on aw (R² = 0.93) and moisture (R² = 0.98), while coconut flour byproduct had a positive significant effect over luminosity ( p < 0.05). The optimized formulation included 20 % coconut flour byproduct, baked for 11 min at 448 W. The pre-gelatinization process produced cavities in the snack, while omitting salt did not significantly affect aw (0.192 ± 0.01 and 0.202 ± 0.01) or moisture (1.23 ± 0.10 and 1.05 ± 0.08 %), when comparing the optimized version without and with salt addition. These findings support the use of coconut byproducts and microwave baking in snack development and suggest that salt content can be reduced without compromising product quality.