Developing hydrocolloid-infused honey fillings for millet cookies: a comparative study against commercially available fat-based alternatives

This study aimed to develop honey fillings for cookies using a variety of hydrocolloids, including xanthan gum (XG), guar gum (GG), and gelatin. The optimization of hydrocolloids concentration in honey for developing honey fillings was successfully achieved through a Box-Behnken design, involving three independent variables: XG (5–10% w/w), GG (0.1–1.5% w/w), and gelatin (8–12% w/w). The effects of these variables were assessed in terms of the honey filling’s baking stability, antioxidant capacity, firmness, and water activity. The ideal concentrations for the honey filling were identified as 5.23% XG, 1.4% GG, and 10.46% gelatin. The physicochemical, antioxidant, and rheological characteristics of the optimized honey filling (OHF) were analyzed and compared to a commercial chocolate filling (CCF) as a reference. OHF displayed slightly lower viscoelastic properties but higher structural stability across all entire strain. OHF demonstrated 24.29% enhancement in antioxidant activity and 29.15% reduction in fat content relative to CCF. Subsequently, OHF was employed as a filling ingredient in cookies and compared to non-filled cookies and CCF-based cookies. The OHF-based cookies exhibited comparable textural attributes and sensory appeal to the CCF-based cookies. However, they displayed 29.37 and 19.89% increase in TPC, 129.89 and 29.93% increase in antioxidant activity, and 35.82 and 120.31% decrease in fat content as compared to non-filled and CCF-based cookies, respectively.