Abstract:

Chitosan was degraded by high pressure homogenization to increase its effectiveness for clarifying
orange juice. The influence of homogenization pressure, temperature, time and pH on clarification of orange juice by
chitosan degradation products was examined by measuring the light transmittance of orange juice. The conditions for
clarifying orange juice at 40 ℃ were optimized using Box-Behnken experimental design combined with response surface
methodology. Results showed that degraded chitosan had obviously preferable clarification effect on orange juice when
compared to the control without degradation. Meanwhile, the response surface model allowed good prediction of juice
transmittance as a function of various homogenization conditions. Homogenization of 0.723 g/L acidic aquesou solution of
chitosan at pH 3.27 for 6.8 min at 32 MPa was found to be optimal. Transmittance was 96.68% for original orange juice and
92.2% for reconstituted orange juice when mixed with the degraded chitosan in a proportion of 1:2.5.

Key words: high pressure homogenization, chitosan, degradation, orange juice, clarification