Optimization of processing conditions for oil reduction of magwinya (a deep-fried cereal dough)

Abstract

Obesity – a known risk factor for some metabolic diseases – is still of global concern deeply rooted in unhealthy diet and lifestyle choices. Magwinya, a wheat-based deep-fried snack, absorbs up to 14% of oil. Wheat bran (WB), can serve as additive for fibre enrichment and oil reduction; hence this investigation on the optimization of WB, fermentation and frying time on oil uptake of magwinya. Using response surface methodology, WB concentration, fermentation time and frying time were independent variables that generated 15 runs from Box-Benkhen experimental design for magwinya production. Responses were weight, diameter, volume, crust and crumb colour, hardness, ash, oil and moisture content. Goals of the optimization process were set to minimize oil and maximize ash contents. Variations in WB and frying time had a significant effect on all dependent variables and WB significantly (p < 0.05) reduced oil by 42.86% and increased ash content by 61.78%. Coefficient of determination (R2) values above 0.8 was used to determine fitness of models. Variables for optimum fried dough were 15 g WB, 120 min fermentation time and 3 min frying time at 0.92 desirability value. Fibre enrichment using WB can significantly improve quality and reduce oil uptake in traditional fried cereal dough.