Optimization of enzyme‐assisted extraction of bioactive‐rich juice from Chaenomeles sinensis (Thouin) Koehne by response surface methodology

Abstract

The aim of this study was to improve the extraction rate (ER) of Chaenomeles sinensis (Thouin) Koehne (C. sinensis) juice via an enzyme-assisted extraction using a combination of cellulase and pectinase. Response surface methodology was used to optimize extraction conditions of juice, including enzymolysis time (X1), pectinase concentration (X2), cellulase concentration (X3), and enzymolysis temperature (X4). Results showed that the highest ER of C. sinensis juice (90.4%) was obtained under the optimal conditions: X11.5 hr, X20.05%, X30.08%, and X450°C. At the same temperature and time (50°C, 1.5 hr), the ER and contents of ascorbic acid, total phenolics, total flavonoids, and total triterpenoids in the juice obtained with the enzymatic treatment were higher than those obtained without any enzymatic treatment. Thus, the optimized enzymatic pretreatment was effective in assisting the production of C. sinensis juice rich in bioactive substances. Practical applications The fruit of Chaenomeles sinensis has a golden color and contains many nutrients and bioactive compounds, such as organic acids, polyphenols (including flavonoids), steroids, oleanolic acid, ursolic acid, unsaturated fatty acids, and fiber polysaccharides, which makes it an ideal food material for pure natural juice with pleasant aroma and health-promoting bioactive substances. However, the conventional juicing methods simply through squeezing and pressing have been proven inefficient in producing juice from the C. sinensis fruit, due to the hard flesh of fruit resulting from its high contents of cellulose and lignin and cross-linked network microstructure. Our results suggested that enzyme-assisted extraction using a combination of cellulase and pectinase not only increased the extraction rate of C. sinensis juice, but also could effectively increase its contents of ascorbic acid, total phenolics, total flavonoids, and total triterpenoids, which will provide a theoretical instruction for the production of C. sinensis juice.