Changes in Quality and the Formation of Nε-Carboxymethyl-Lysine and Nε-Carboxyethyl-Lysine during Air-frying of Pleurotus eryngii

The fluorescent advanced glycation end products (AGEs) and two typical AGEs, Nε-carboxymethyl-lysine (CML) and Nε-carboxyethyl-lysine (CEL) were identified in Pleurotus eryngii chips using fluorescence spectroscopy and ultra-performance liquid chromatography-triple quadrupole tandem mass spectrometry, respectively. Additionally, the effect of frying temperatures and times on the quality of Pleurotus eryngii chips was investigated. The results showed that the Pleurotus eryngii chips underwent browning during the frying process, with the color changing from white to golden yellow. The color intensified as the air-frying time and temperature increased. The crispy slices had a significantly (P<0.05) reduction in moisture content, while their hardness first dropped and subsequently rose. In addition, during the frying process, both the frying time and temperature significantly (P<0.05) impacted the formation of CML and CEL in Pleurotus eryngii, with their levels increasing with higher frying temperatures and longer frying times. The concentrations of CML and CEL peaked at 13.75 and 70.63 μg/g, respectively, after 180 ℃ for 20 min. The amounts of fluorescent AGEs generated at 180 ℃ for 10 min was 4.5 AU higher than at 160 ℃ for 10 min (P<0.05). The contents of CML and CEL were 4.54 and 8.34 μg/g, respectively, after 10 minutes at 160 ℃. These values were 46.65% and 62.48% lower than those observed after 20 min at 160 ℃. Under these conditions, the sensory evaluation was better, and the difference was not significant compared with 180 ℃ and 10 min, while the formation of AGEs was lower. Thus, the ideal frying condition of Pleurotus eryngii chips determined based on all parameters is at 160 ℃ for 10 min.