Effect of drying methods on the production of ora-pro-nobis peel flour and its application in gluten-free cupcakes

The ora-pro-nobis fruit has great potential for the food industry due to its bioactive compounds and antioxidant capacity. Additionally, the fruit peels, generated as waste during mucilage extraction, can be utilized in the production of flours, diversifying functional ingredients, especially in gluten-free products. This study aimed to evaluate the effects of different drying techniques on the production of flours from ora-pro-nobis fruit peels and investigate their application in gluten-free cupcakes. The peels were dried in a hot-air oven (60 ºC for 72 hours) or freeze-dried (0.998 mbar at -40 ºC for 48 hours), ground, sieved, and the resulting flours were characterized in terms of physicochemical properties, bioactive compounds, color, and solvent retention capacity. Among the flours obtained, the one subjected to freeze-drying showed higher protein contents, pigment retention, and solvent retention capacity. Therefore, it was used in the production of gluten-free cupcakes, which were compared with the control formulation (wheat flour) in terms of texture and color profiles. Despite significant differences, the gluten-free cupcakes with a lower concentration of freeze-dried ora-pro-nobis peel flour exhibited textural characteristics closer to those of traditional cupcakes. On the other hand, the formulation with a higher concentration of flour presented colorimetric parameters that were more similar. It is concluded that ora-pro-nobis peel flour, especially the freeze-dried one, has great functional and nutritional potential in gluten-free products, requiring adjustments in the flour proportions in the formulations.