Nutritional, Functional, and Antioxidant Properties of Biscuits Prepared from Wheat Flour Supplemented with Defatted Chia Seed and Turmeric Powders

Abstract

This study examined the nutritional, functional, physicochemical, antioxidant, and sensory characteristics of biscuits formulated by partially replacing wheat flour (72% extraction) with 5–20% defatted chia seed powder, along with a fixed addition of 2% turmeric rhizome powder.Chemical composition analysis revealed that chia powder was exceptionally rich in protein (33.50%), fiber (30.90%), and minerals (Ca, P, Mg, Zn), whereas turmeric provided higher crude fat (6.80%), potassium, iron, and manga-nese, along with superior antioxidant activity (TPC: 115 mg GAE/100 g; TFC: 21 mg QE/100 g; inhibition: 90%). In contrast, wheat flour exhibited the lowest protein, fiber, ash, and mineral contents but the highest carbohydrate level (85.40%). Amino acid profiling demonstrated that defatted chia offered a complete and balanced essential amino acid composition, surpassing the FAO/WHO/UNU (1985) reference pattern, while wheat protein remained limited in lysine, threonine, and methionine. Biscuit formulations enriched with chia and turmeric showed significant nutritional improvements compared to the control. Protein con-tent increased from 9.87% (control) to 12.64% (B20), crude fiber from 0.61% to 4.47%, and minerals such as calcium and po-tassium by more than sixfold and threefold, respectively, while available carbohydrates and energy density declined. Physical properties were altered, with increasing substitution leading to reduced diameter, thickness, and spread ratio but higher hardness. Color measurements confirmed a darker, more reddish-yellow crust due to chia pigments and turmeric carotenoids. Sensory evaluation revealed that biscuits containing up to 10% chia with 2% turmeric maintained high consumer acceptability, while higher substitution levels (>15%) reduced preference due to texture and flavor changes. Overall, incorporating defatted chia seed powder and turmeric rhizome powder significantly enhanced the nutritional and functional quality of biscuits, providing higher protein quality, dietary fiber, minerals, and antioxidants. These findings highlight their potential as functional ingredients to de-velop nutrient-dense bakery products that support health promotion.