Textural Characterization of Protein and Fibre Enriched Okara Cookies Incorporated with Hydrocolloid and Fat Replacer

Abstract

This study explores the potential of okara flour, a nutrient-rich by-product of soybean processing, as a sustainable ingredient for developing protein- and fiber-enriched cookies while maintaining desirable quality attributes. Cookies were formulated using okara flour (50%) and evaluated through physical, proximate, bioactive, instrumental textural, and sensory analyses, with additional modifications using fat replacers (maltodextrin and polydextrose at 0–30%) and hydrocolloids (guar gum, xanthan gum, and their blends) to improve product performance. Characterization of okara confirmed its high protein (31.93%), fiber (11.17%), and antioxidant content, supporting its functional value. Cookies containing 50% okara flour achieved significant protein enrichment but exhibited a softer texture and lower sensory scores, mainly due to beany flavour and changes in dough structure. Incorporation of fat replacers showed that moderate fat substitution up to 20% improved cookie spread, texture, and overall acceptability, while higher levels adversely affected hardness and flavour. Further optimization with hydrocolloids demonstrated that a 1% guar–xanthan gum blend (1:1) provided the best balance of dough handling, texture, and sensory quality, resulting in the highest consumer acceptance. Overall, the findings indicate that careful use of fat replacers and hydrocolloids can successfully offset the technological challenges of okara incorporation, enabling the development of nutritionally enhanced cookies with acceptable sensory quality and promoting the effective utilization of this sustainable food by-product.