Abstract: A study was made of the effects of various clarification methods on pear juice physico-chemical properties and sensory evaluation indices. The experiments were carried out in a home-made microfiltration device with hollow fiber membranes ultrafiltration device and pectinase treatment. Results showed that: (1) The impact of aperture 0.2μm inorganic membrane microfiltration was not noticeable on the physico-chemical properties (soluble solids, Vitamin C, reducing sugar); the loss of pear juice volume was not big; the flavour and aroma of pear were retained better in clear pear juice. It was an appropriote measure for clarifying pear juice. (2) Since the aperture of 50nm inorganic membrane and hollow fiber membranes were too small, they were not appropriate for clarifying pear juice. (3) After the aperture 0.8μm inorganic membrane microfiltration and pectinase treatment, the turbidity value of finished product of pear juice was too high, and there were delamination and deposition in it after a not long time. They were not appropriate for clarifying pear juice too.

Key words: pear juice, clarification, microfiltration, ultrafiltration, pectinase