Functional and nutritional properties of tigernut-wheat flour and its in-vitro glycemic modulation potential

Abstract

Aim: The study investigated the nutritional, functional, antioxidant, and enzyme inhibitory properties of tigernut-wheat composite flours. Methods: Composite samples were prepared by substituting wheat flour with tigernut flour at 5–20%, while 100% wheat flour served as the control. Proximate, functional, antioxidant, and enzyme inhibitory analyses were carried out on the composite flours to determine the effects of tigernut substitution. Results: Proximate analysis revealed that tigernut addition significantly increased fiber (1.08–3.22%), ash (0.83–3.20%), and fat (2.61–7.32%) contents. While the crude protein content decreased slightly at higher substitution (13.00–6.91%), the carbohydrate content did not follow any specific pattern. Functional properties such as water absorption (73.13–85.26%) improved with tigernut incorporation, while bulk density and foaming capacity also showed positive trends. Antioxidant indices demonstrated substantial enhancement: total phenolic content (2.20–8.87 mg GAE/g) and improved radical scavenging activities. In addition, α-glucosidase inhibition rose from 27.25% in the control to 64.86% in the highest blend, while α-amylase inhibition declined, indicating potential benefits for moderating postprandial glycemia. Conclusions: Tigernut substitution enriched the mineral and phytochemical content of wheat flour and enhanced its functional and antioxidant properties. These findings suggest that tigernut-wheat composite flour could serve as a functional ingredient for bakery and snack formulations, offering improved nutritional quality and preliminary benefits related to glycemic modulation.