Characterization of roll-pulps: a functional snack from co-products of apple juice production

Abstract

This study explores the development of innovative fruit-based snacks, specifically roll-pulps, derived from apple juice production co-products, aiming to promote healthier dietary habits and contributing to food waste reduction. Fruit intake remains below recommendations, highlighting the need for convenient, nutrient-rich products. Apple co-products were processed into roll-pulps, and their polyphenols and antioxidant stability were analyzed. Total polyphenol content of apple pulp measured was 5.94 mg g⁻¹ fresh weight (FW), with 80% recovery post-processing into roll-pulps. HPLC analysis indicated that key polyphenols such as chlorogenic acid, epicatechin, phloretin, and phloretin xylosyl-glucoside, remained largely stable. Procyanidins content decreased after dehydrations whilst rutin showed an increase in concentration. The total polyphenol content of the pulp, as determined by HPLC, was 0.70 mg g⁻¹ FW with 66% recovery after processing. DPPH and FRAP assays showed high antioxidant retention (84% and 90%), confirming bioactive stability at 70 °C. The incorporation of additives, including agave syrup and maltodextrin, modulated textural and mechanical properties, influencing hardness, chewiness, flexibility, and water activity. These results show the feasibility of converting apple juice co-products into sustainable, health-promoting snacks, supporting circular economy efforts to reduce food waste.