Title : Recovery of high-value compounds from orange peel extract (Citrus sinensis) filtration using surface modified membranes
Abstract:
The production of orange juice generates significant amounts of by-products, particularly orange peel and pulp residues, which are rich in bioactive compounds such as polyphenols. These compounds possess high antioxidant activity and can serve as natural preservatives in food products, offering a sustainable alternative to synthetic antioxidants. However, their efficient extraction and purification remain a challenge, requiring innovative separation techniques that maximize yield while maintaining the integrity of these valuable molecules.In this context, membrane technology, particularly the use of surface-modified polymeric membranes, presents a promising solution for the recovery and concentration of polyphenols from orange peel extract. By tailoring membrane properties through surface modifications, it is possible to enhance selectivity and permeability, improving the separation process. This approach not only contributes to the valorization of citrus by-products but also promotes a more sustainable and circular approach in the food industry by reducing waste and utilizing natural compounds with potential health benefits. Thus, this study aimed to evaluate the ability to recover polyphenols from orange peel extract using membrane technology. For this purpose, the surface modification of polyethersulfone microfiltration membranes was performed layer by layer using sulfuric acid, polyethyleneimine, and graphene oxide. The results demonstrated a permeability of 406 L/h·m²·bar, suggesting that membrane modification reduced the effective pore size. The average flux obtained was 1.97 ± 0.34 L/h·m². The quantitative analysis of polyphenols using the Folin-Ciocalteu method revealed concentrations of 25.7 mg GAE/100 g in the concentrate and 31.22 mg GAE/100 g in the permeate. Additionally, the treatment resulted in a 34.6% color removal and a 61.5% reduction in turbidity. Therefore, the modified membrane can be considered an emerging technology capable of recovering and purifying phenolic compounds present in orange residues, standing out as a low-energy and easily applicable methodology, contributing to the valorization of juice industry by-products.
