Fortification of wheat biscuits with chia seed fiber and flower waste: Nutritional, antinutritional, functional, and storage properties

This study explored the innovative application of Chia Seed ( Salvia hispanica L.) by-products, including fiber-rich fractions (FRF) from oil-extracted meal and dry chia flower (DCF) waste powder, in wheat biscuits. By partially substituting wheat flour with these sustainable ingredients at 20 %, 30 %, and 40 % levels, aimed to enhance the nutritional profile and functional properties of biscuits. The fortified formulation demonstrated significant improvements in dietary fiber (4.80 g to 20.06 g/100 g), protein (10.88 g to 15.57 g/100 g), unsaturated fatty acids (12.20 g to 19.17 g/100 g), alongside reduced reducing sugars (38.16 g to 16.98 g/100 g) compared to control biscuits. Antinutritional factors also decreased significantly, with tannins (153.6 to 4.3 mg/100 g), phytates (108.7 to 3.4 mg/100 g), and trypsin inhibitors (96.4 to 3.78 mg/100 g) being markedly reduced in C20 formulations. Sensory analysis revealed that the 30 % substitution (C15) offered the best balance of taste, texture, and overall acceptability. Physicochemical analysis showed improved hydration such as oil-holding, swelling, and water retention capacities in enriched biscuits. Antioxidant activity increased with substitution levels, with C20 showing the highest values: DPPH (12.02 %), TPC (111.0 mg GAE/100 g), TFC (512.4 mg QE/100 g), and FRAP (133.1 µmol Fe (II)/g). Acrylamide (116.7–299.3 µg/kg) and hydroxymethylfurfural (10.67–55.00 mg/kg) levels were within manageable limits in optimized formulations. Storage stability tests over six months confirmed the oxidative and sensory resilience of the biscuits. These findings underscore the potential of CS by-products as functional ingredients in baked goods, aligning with sustainability goals and consumer demand.