Structural characterization, gelling properties, and beef preservation applications of pectin extracted from...

The growing demand for sustainable food additives has spurred interest in pectin extracted from agricultural byproducts. This study investigated the structural, gelling, and antimicrobial properties of pectin extracted from sweetpotato residue (SPP) using a green hydrothermal method. Optimal extraction conditions (122.4 °C, 19.1 min, liquid-solid ratio of 20.8 mL/g) yielded a maximum pectin extraction rate of 3.05 %. The extracted SPP was characterized as a highly methoxylated pectin with a main peak molecular weight of 57.87 ± 4.6 kDa. Structural analysis revealed abundant galacturonic acid and rhamnogalacturonic acid I domains in both SPP and alkali-modified sweetpotato pectin (MSPP), as confirmed by FT-IR and ¹H NMR. SPP and MSPP exhibited smaller particle sizes and higher negative charges compared to citrus pectin (CP) and modified citrus pectin (MCP). Modified pectin exhibited reduced antioxidant activity versus CP. MSPP formed Ca²⁺-induced gels across pH 4-11.5 without sugar, showing superior water retention and stable networks. Additionally, 3 % SPP effectively inhibited the growth of E. coli and S. aureus. As a coating, SPP extended beef shelf life by 3 days by maintaining color stability and suppressing microbial growth. These findings position sweetpotato residue pectin as a promising, Eco-preservative, with tailored functionality achievable through structural modification.