Sustainable valorization of peach palm (Bactris gasipaes Kunth) peel flour to improve nutritional properties and carotenoid bioaccessibility in gluten-free cookies

Abstract

The growing demand for gluten-free bakery goods has increased interest in ingredients that improve physicochemical properties and nutritional value. Agro-industrial by-products are promising due to their health-related composition. Peach palm peel, a highly discarded Amazonian by-product, is rich in carotenoids; however, its application in food products remains limited. This study formulated gluten-free cookies by replacing rice flour with peach palm peel flour (PF) at 10 and 20%, and evaluated their physical, nutritional, and carotenoid composition, as well as in vitro bioaccessibility. Substitution with 20% PF increased dietary fiber, fat, and protein contents, and resulted in cookies with larger diameter and greater hardness. Scanning electron microscopy analysis revealed denser matrices in PF-added formulations. Seventeen carotenoids were quantified in PF and cookies, with all-E-β-carotene and all-E-lutein being predominant. Carotenoid bioaccessibility remained similar between 10% and 20% PF, and its modulation was influenced by lipid and dietary fiber contents, as well as by changes in the carbohydrate-rich food matrix resulting from PF substitution. Overall, PF incorporation enhanced the nutritional quality and modified relevant physical characteristics of gluten-free cookies while delivering substantial amounts of bioaccessible provitamin A carotenoids. These findings highlight PF as a functional and sustainable ingredient and an alternative strategy to valorize Amazonian fruit by-products.