Coffee Silverskin Extract-Functionalised Pectin: A Sustainable Substrate to Obtain Chicken Meatballs with Antioxidant and Improved Sensory Properties

Chicken meatballs were formulated with high-methoxyl pectin functionalised with phenolic compounds extracted from coffee silverskin through an enzymatic conjugation process, with the aim of developing a functional food with improved antioxidant properties and acceptable sensory quality. Functionalised pectin was incorporated at 2.5% into chicken meatball formulations, while parallel controls containing non-functionalised pectin were prepared. At day 0, functionalised meatballs (PLF0) exhibited a total polyphenol content of 10.44 mg GAE/g, significantly higher than controls (PB, 2.74 mg GAE/g). Antioxidant capacity, expressed as IC30 against the ABTS·+ radical, was 0.0127 mg mL-1 in PLF0 compared to 0.8982 mg mL-1 in PB0. After 5 and 10 days of storage at +4°C, functionalised samples retained markedly higher antioxidant potential, with IC30 values nearly 9-fold lower than PB5 and 14-fold lower than PB10, respectively. Cooking preserved these benefits: PLFC maintained a TPC of 9.33 mg GAE/g and an IC30 of 0.1129 mg mL-1, while controls showed lower TPC (5.54 mg GAE/g) and weaker activity (1.4920 mg mL-1). Sensory evaluation revealed that the incorporation of functionalised pectin did not adversely affect the visual appearance, odor, or texture of chicken meatballs. Both raw and cooked formulations maintained comparable acceptability to controls, with no significant differences in overall liking. Notably, the functionalised meatballs retained their characteristic sensory profile after 10 days of refrigerated storage, confirming that the enrichment with coffee silverskin-derived conjugates did not impair consumer-relevant attributes. Overall, these results demonstrate that functionalisation of chicken meatballs with coffee silverskin extract enhances polyphenol content and antioxidant stability while preserving desirable sensory qualities, making this approach a promising strategy for the development of antioxidant-enriched meat products.