Investigation of physicochemical, bioactive, textural and sensory properties of gluten-free cakes enriched with kumquat (little jewel of citrus) flour

Kumquat is a citrus fruit utilized both in its fresh form and in a variety of culinary preparations. It possesses a distinctive hue, substantial nutritional benefits, and advantageous phytochemical. Being consumed in its entirety (including peel and fruit), it generates no waste and qualifies as an eco-sustainable food. In this study, kumquat was dried and included in the formulation of gluten-free cake (GFC) as a substitute for rice flour, resulting in a product abundant in polyphenols, antioxidants and dietary fiber for celiac patients. Initially, the physicochemical parameters of kumquat flour were assessed, and the impact of kumquat flour at 5%, 10%, and 15% concentrations on GFC qualities (color, bioactive compounds, texture, and sensory attributes) was examined. The optimal outcomes were identified in samples augmented by 15% (GFC15). The results indicate that the total phenolic content of the samples was 296.85 mg GAE/100 g, the antioxidant capacity (DPPH-ABTS) ranged from 221.87 to 198.35 µmol Trolox/100 g, and the total flavonoid content was 86.11 mg QE/100 g. Furthermore, the pale color of the GFC has been eradicated from both the crust and the crumb. A statistically significant difference was seen among the samples in all parameters except for appearance (4.02) and chewiness (3.55) (p > 0.05). The GFC15 sample obtained the highest ratings from the panelists for color (4.09), taste (4.12), aroma (3.55) and overall acceptability (4.33) (p < 0.05). The findings indicate that GFC15 samples surpass the control group (100% rice flour) regarding physicochemical, nutritional and sensory attributes, indicating that kumquat flour is a viable option in gluten-free baking formulations.