Inhibition of advanced glycation end-products in frozen-thawed and reheated pork by pigskin gelatin hydrolysates

This study investigated the effects of pigskin gelatin hydrolysates (PGH, 4 %) as a cryoprotectant on the formation of advanced glycation end-products (AGEs) in pre-heated pork subjected to freeze-thaw cycles and subsequent reheating. During the freeze-thaw process, PGH significantly mitigated the increase in α-dicarbonyl precursors (α-DPs) and AGEs compared to the control group. Specifically, the levels of glyoxal and methylglyoxal decreased by 4.26 % and 6.12 %, respectively, although this inhibition was not statistically significant (P > 0.05). The concentrations of Nε-(carboxymethyl)lysine (CML) and Nε-(carboxyethyl)lysine (CEL) content in the PGH-treated group were 2.86 %-33.19 % and 4.33 %-24.02 % lower than those in the control group, respectively. After reheating (100 °C, 10 min), AGEs levels increased by 1.94 % to 123.21 %, while the levels of glyoxal and methylglyoxal decreased by 17.00 % and 15.24 %, respectively. The addition of PGH significantly reduced AGEs formation after reheating compared to the control (P < 0.01). These results suggest that PGH is effective as a cryoprotectant, inhibiting the formation of harmful AGEs during freeze-thaw cycles and subsequent reheating of pre-heated pork.