Effects of cooking approaches on the quality traits, lipid profiles and flavor volatiles of Zhenba Larou: insights from lipidomics and GC–IMS

To elucidate the interactions among the physicochemical properties, lipids, and volatile compounds, the sensory evaluation, cooking loss, shear force, moisture migration, lipid oxidation, and color values of Zhenba Larou cooked by different methods (boiled, steamed, and microwaved) were investigated. Their differences in lipids were characterized using UPLC–Q Exactive–MS lipidomics, and flavor volatiles were further characterized via E-nose and GC–IMS. The results revealed that the steaming treatment led to the lowest cooking loss (18.1%), moderate shear force (11.11 ± 1.24 kgf) and TBARS value (1.644 ± 0.059 mg MDA/kg) and the highest sensory acceptability and b⁎ value (8.40 ± 1.78), whereas the microwave treatment led to the greatest cooking loss (45.06%), shear force (22.44 ± 3.14 kgf), TBARS (1.879 ± 0.098 mg MDA/kg), and a⁎ value (17.43 ± 0.94). In total, 1257 lipid metabolites were detected in the cooked Larou samples. Glycerophospholipids (GPs), glycerolipids (GLs), and sphingolipids (SPs) constitute the predominant lipid categories. Compared with those of the CK samples, the GP contents of the three cooked samples increased significantly (P < 0.05). Additionally, the E-nose results indicated significant disparities in sensor responses among different cooking methods. A total of 62 volatile compounds were detected among all the Larou samples, and aldehydes (29%), ketones (29%) and esters (14.5%) were the predominant categories. After multivariate statistical analysis, eight potential differential biomarkers were ultimately selected when VIP > 1 and ROAV>1, including hexanal-M, hexanal-D, butanal, 3-hethyl butanal, 2-hethyl butanal, acetic acid, propanal, and acetoin-D. Correlation analysis indicated that LPC(20:0/0:0) correlated positively with hexanal (P < 0.01), while a significant negative correlation was observed between it and propanal and acetoin-D (P < 0.05). TBARS is positively correlated with LPC(22:5/0:0), LPC(0:0/22:5), LPC(0:0/20:2), LPC(20:2/0:0), and LPC(0:0/18:1) (P < 0.01). Overall, the steaming treatment resulted in better quality characteristics. These results provide reference data for the development and quality control of precooked Zhenba Larou products.