Abstract: 【Objective】This study explored the differences and causes of oat lipase activity of different varieties. Providing a theoretical basis for screening varieties with low lipase activity and achieving stable enzyme inactivation effect of oat products. 【Method】Six main varieties of three main oat planting regions were selected for the study, and their lipase activity, nutritional indexes, physical traits, and agronomic indexes were measured. To answer the differences in lipase activity of oat varieties, the indicators significantly related to oat lipase were screened by correlation analysis. Through cluster analysis, classified multiple oat samples by lipase activity. Transform data having correlations into composite variables for statistical analysis by principal component analysis. To derive a predictive model for lipase activity, an analytical method combining gray correlation and multiple stepwise regression was used. The indicators correlating with lipase activity were used as independent variables, and the lipase activity was used as dependent variables for quantitative model fitting. 【Result】Lipase activity was significantly positively correlated with crude fat content (r=0.32, p<0.05), and the various trends of fat content, unsaturated fatty acid content, lipase activity, and acid value were consistent. Lipase activity was significantly positively correlated with crude protein content (r=0.46, p<0.01), and the higher lipase activity was, the higher percentage of electrophoretic bands located in 31-43 kD were. It was significantly negatively correlated with grain test weight (r=-0.71, p<0.01) and positively associated with growth period (r=0.37, p<0.01). Baiyan 18 and Diyan 1 were low lipase activity and high nutrition varieties according to grey relational analysis, and the relevance value with ideal variety X₀ were 0.951 and 0.883, respectively. Stepwise regression analysis only retained the test weight and protein content as independent variables. The prediction model of lipase activity was established as Y=720.274－2.255×test weight (g·L^-1)+75.761×protein content (%), p<0.01, R² = 0.658.【Conclusion】The varieties had significant effects on oat lipase activity. Protein content, fat content, test weight, and growth period were the main influencing factors of oat lipase activity. Grey relational analysis combined with stepwise regression analysis could be used to comprehensively evaluate oat varieties effectively and quickly select varieties with low lipase activity.

Key words: oat varieties, planting area, lipase activity, correlation analysis, prediction model