Comparative Effectiveness of Synthetic and Natural Antioxidants on the Oxidative Stability of Lard

The oxidative stability of animal fat is crucial for maintaining nutritional quality and food safety. This study aimed to evaluate the effects of four phenolic antioxidants (i.e., tert-butylhydroquinone, TBHQ; propyl gallate, PG; butylated hydroxytoluene, BHT; vitamin E, VE) on the stability of lard. The inhibitory effects of different antioxidant concentrations were comprehensively assessed using chemical index analyses, free radical scavenging assays, and electron paramagnetic resonance (EPR). The results showed that three synthetic antioxidants performed significantly better than VE, with TBHQ and PG exhibiting the best overall antioxidant performance. Specifically, TBHQ (0.2 g/kg) most effectively suppressed the increase in the peroxide value and was ranked first in the principal component analysis. PG significantly reduced the anisidine value (4.01) and demonstrated the best DPPH scavenging capacity (55.59 μmol TE/100 g). Notably, TBHQ presents certain toxicological concerns, whereas PG exhibits comparatively lower toxicity. Consequently, for practical industrial applications, PG should be prioritized as the antioxidant of choice for lard. Based on the EPR radical-scavenging results and known antioxidant chemistry, it was inferred that the antioxidants quenched superoxide anion radicals via hydrogen-atom and single-electron transfer mechanisms, thereby interrupting the oxidative chain reaction. This study provides a theoretical basis for the scientific selection of antioxidants in lard and offers guidance for ensuring food safety and nutritional quality.