Pea protein–Artemisia sphaerocephala Krasch gum interpenetrating-network emulsion gel as a fat replacer in pork meatballs: Water retention, texture, oxidation, and freeze–thaw stability

Abstract Emulsion gels can replace pork backfat in comminuted meat products, but their performance depends on replacement level and processing process. This study evaluated a vitamin E-loaded pea protein isolate– Artemisia sphaerocephala Krasch gum (PPI–ASKG) interpenetrating-network emulsion gel in pork meatballs. Pork backfat was replaced by the emulsion gel at mass ratios of 0%, 25%, 50%, 75% and 100%, and quality attributes of the meatballs were measured before and after freeze–thaw cycles (FTCs). The water-holding capacity increased initially and then decreased, peaking at the 25% replacement level (E25). E25 also exhibited the lowest cooking loss (4.27% vs. 5.98% for the full-fat control) and thawing loss (3.2% vs. 6.5% for the full-fat control), while hardness, gumminess and chewiness remained comparable to those of the fresh-control. The 50% replacement level (E50) maintained low cooking and thawing losses, whereas higher replacement levels increased liquid losses and reduced hardness by up to 49.1%. After FTCs, the gel-containing formulations retained higher lightness and lower thiobarbituric acid reactive substances (TBARS) values than the control. A moderate replacement level (25–50%) mitigated freeze–thaw damage to the myofibrillar protein network and retained immobilized water, thereby stabilizing the WHC of meatballs. Electronic-nose analysis further revealed that sulfur-containing volatile responses increased progressively with the replacement level, reflecting the beany off-flavor of pea protein. These findings provide a practical approach for reducing the saturated fat content of meatballs while improving water retention and freeze–thaw stability without compromising texture.