Extraction, structural characterization, and antioxidant of pectin from pomelo peel

Abstract Pomelo peel is a significant agro‐industrial by‐product that offers a promising source of pectin. The extraction conditions are crucial in determining both the yield and functional properties of this pectin for high‐value applications. This study investigates the effects of extraction pH, temperature, and time on the yield, structural characteristics, and antioxidant activity of pectin extracted from pomelo peel. The results indicate that all three variables significantly influence pectin yield ( p < 0.05), with the maximum yield of 23.67 ± 0.85% attained under conditions of pH 1.5, a temperature of 85°C, and an extraction time of 2.0 h. Higher yields are associated with significant structural changes: lower pH, increased temperatures, and longer extraction times lead to decreases in molecular weight, the degree of methylation, and the content of neutral sugar side chains (notably arabinose and galactose). Interestingly, this structural degradation enhances the DPPH and ABTS + ·radical scavenging activities, suggesting an inverse correlation between antioxidant capacity and molecular weight. Moreover, protein content decreases under harsh acidic and high‐temperature conditions, likely due to degradation and/or loss via side chain cleavage. This research offers valuable insights into the potential application of pomelo peel pectin as a versatile biopolymer for food and biomedical industries.