5-hydroxymethyl-2-furfural and acrylamide formations in black garlic during aging period and their correlations with browning degree

Solo-bulb black garlics (SBBG) are novel foods rich in nutritional and functional ingredients. However, certain process contaminants formed during thermal processing of SBBG raise safety concerns. This study investigated the formations of 5-hydroxymethyl-2-furfural (5-HMF) and acrylamide, as well as the browning degree of SBBG during a 12-day aging period. Both 5-HMF and acrylamide contents exhibited exponential increases, with their formations well simulated by pseudo-first-order kinetic models. 5-HMF formation showed a significant positive correlation with fructose content (p < 0.05), while acrylamide formation was strongly associated with asparagine content (p < 0.01). Browning degree correlated significantly with acrylamide accumulation and asparagine content (p < 0.01), but not with 5-HMF (p > 0.05). These results indicate that fructose and asparagine accumulations play critical roles on 5-HMF and acrylamide formations in SBBG, respectively, and acrylamide accumulation promotes SBBG browning. Notably, acrylamide level in SBBG exceeded those reported in some commonly consumed foods, which is a concern considering the daily consumption of this food.