Nutritional and sensory properties of maize bran and germ enriched cookies and their effect on blood lipids in Wistar rats.

Abstract

Non-communicable diseases (NCDs) are a growing burden in Uganda, largely attributed to unhealthy dietary patterns characterized by low dietary fiber. Maize (Zea Mays L.) is a widely consumed cereal in Uganda, yet its nutrient-rich milling by-products are underutilized. This study aimed to evaluate the nutritional and chemical properties of cookies enriched with maize germ and maize bran and to assess their effect on blood lipids and glycemic response using a rat models. Cookies were formulated with varying proportions of maize bran (0-60%) and maize germ (0-30%) and evaluated for sensory acceptability using a 9-point hedonic scale. Sensory acceptability revealed that moderate levels of bran and germ inclusion maintained acceptability. Higher levels of maize bran and maize germ had a negative impact on acceptability scores for texture, taste, and overall acceptability. Three formulations containing 25% bran and 15% germ, 48% bran and 15% germ, and 60% bran and 17% germ respectively were selected for proximate analysis. Dietary fiber, ash, and crude protein were determined using standard AOAC methods. Carbohydrates were determined by difference and total phenolics were determined using Folin Ciocalteu method. Proximate analysis revealed that incorporation of maize bran and germ significantly increased dietary fiber, ash, and total phenolic content, while reducing carbohydrate content compared to control cookies. Animal experiments using Wistar rats assessed the glycemic responses and lipid profile following cookie consumption. Rats fed maize germ and bran enriched cookies exhibited improved glycemic control and lipid profiles compared to those fed on high fat diet alone. A 60% maize bran enrichment resulted in a significantly more pronounced hypolipidemic effect than the 48% maize bran formulation (medium fiber cookies). These findings suggest that incorporating maize bran and germ into baked products enhances nutritional quality and can support dietary strategies to prevent and manage CVDs. This presents a valuable opportunity to promote affordable, functional foods in low income countries like Uganda.