Correlation analysis between quality indicators of corn flour and properties of extruded puffed foods and screening of key quality indicators for extrusion-special corn flour

To explore the correlation between corn flour quality indicators and the quality of extruded puffed foods, and to screen the key quality indicators and their optimal ranges of corn flour for extrusion puffing, eighteen corn flour samples with diverse quality characteristics were selected in this study. The physicochemical and processing properties of corn flour as well as the quality attributes of corresponding extruded products were determined and analyzed. Multivariate statistical methods, including coefficient of variation analysis, correlation analysis, principal component analysis (PCA), and cluster analysis, were applied to systematically clarify the relationship between corn flour quality and product quality, so as to screen the key quality indicators and their optimal ranges for extrusion puffing processing. The results showed that peak viscosity, fat content, ash content, total starch content, protein content, and water-holding capacity were the key quality indicators significantly affecting the quality of extruded puffed foods. A comprehensive quality evaluation model for extruded products was established based on PCA: F=(46.886Z₁+16.234Z₂+12.013Z₃)/75.134. Cluster analysis was further performed according to the comprehensive scores calculated by the established model. The optimal threshold ranges of key quality indicators of corn flour suitable for extrusion puffing were determined as follows: peak viscosity, 2 759-5 103 mPa·s; fat content of 1.22%-1.90%; ash content of 0.24%-0.86%; total starch content of 72.5%-78.4%; protein content of 5.25%-7.91%; and water-holding capacity of 1.75-1.99 g/g. This study provides a theoretical basis for the targeted screening and industrial production of extrusion-special corn flour.