Multivariate statistical analysis of the quality of apple juice to integrate and simplify juice industrial production technologies

Apple juices produced from nine different industrial production technologies were obtained in pilot scale, for simplifying and integrating the production technologies according to the quality comparison of juices. Juice quality characterized by total phenolic content (TPC), total flavonoid content (TFC), total soluble solid (TSS), stability, turbidity, titratable acidity and pH was investigated. The TPCs of traditional pulping combined with belt-style pressing (TP+BSP)-based juices were higher than that of cold pulping combined with horizontal spiral centrifuge separation (CP+HSCS)-based juices, while the CP+HSCS juices showed higher turbidity than the TP+BSP juices. Principal component analysis, liner discriminant analysis and cluster analysis were applied for analyzing juice quality. Nine production technologies were well separated into three categories and that pulping, juicing and sterilizing methods were the main factors affecting the overall juice quality. Our study provided a method to simplify and integrate the current industrial production technologies of juices.

Abbreviations: TPC: total phenolic content; TFC: total flavonoid content; TSS: total soluble solid; TA: titratable acidity; TP+BSP: traditional pulping combined with belt-style pressing; CP+HSCS: cold pulping combined with horizontal spiral centrifuge separation; NFC: not from concentrate; PCA: principal component analysis; LDA: liner discriminant analysis; HCA: hierarchical cluster analysis.