Emulsifying and ethanol-induced gelling properties of capsicum pectin: The impact of capsicum variety and deproteinization using the Sevag method

This study investigated the emulsifying and ethanol-induced gelling properties of capsicum pectins from bell pepper and chili pepper, and also examined the effect of deproteinization (using the Sevag method). The research revealed that bell pepper pectin (BPP) formed smaller aggregates (337 nm at pH 2) with a higher hydrophobicity in solution due to its lower molecular weight (2.02 × 105 g/mol) and higher degree of esterification (82.15 %) compared to chili pepper pectin (CPP) (3.29 × 105 g/mol, 78.33 %). Consequently, BPP exhibited superior interfacial tension reduction ability, resulting in emulsion with smaller droplet size (483 nm at pH 2). Conversely, CPP showed superior ethanol-induced gelling property in comparison to BPP, as its lower degree of esterification and higher molecular weight facilitated hydrogen bonding interactions and crosslinking during gelation. Deproteinization with the Sevag method reduced protein content, molecular weight and esterification degree of BPP and CPP, but its impact on their emulsifying properties differed significantly. Interestingly, deproteinization notably improved the ethanol-induced gelling property of both pectins, since the increased carboxyl groups in the deproteinized products promoted hydrogen bonding during gelation. This study could facilitate the comprehensive utilization of capsicum and also advance our understanding of the impact of the Sevag method.