Effect of Extraction Method on Yield and Quality of Citrus depressa Juice

Certain qualitative properties of Citrus depressa juice extracted by belt-press, centrifugal, and screw-press extractors were investigated to evaluate the methods for extracting Citrus depressa juice currently used in Japan. Among the three methods, juice yield was highest with screw-pressing. The migration rate of polymethoxyflavonoids (PMF) to the juice was also highest with screw-pressing. Screw-pressed juice had different physicochemical properties from the other two types of juices, and it was evaluated as being unsuitable for drinking following a sensory test. Citrus depressa juice processed by belt-press and centrifugal extractors had lower juice yield and a lower migration rate of PMF. Citrus depressa juice processed by centrifugal extractors was evaluated by a sensory test as being the best of the three types of juices for drinking. PMF and vitamin C found in Citrus depressa juice were largely retained during filtering, sterilizing, and bottling after being extracted with these three methods.