Pre-concentration of Apple Juice with Different Reverse Osmosis Membranes

역삼투막을 이용한 사과쥬스의 예비농축

  • 김길환 (한국과학기술원 식품공학연구실) ;
  • 박현진 (미국 죠지아대학교 식품공학과) ;
  • 김동만 (한국과학기술원 식품공학연구실)
  • Published : 1988.06.01

Abstract

The clarified apple juice was pre-concentrated by reverse osmosis system as a trial for reduction of heat treating time and quality drop in concentration of the juice. The permeate fluxes through CA 865 and CA 960 membranes were higher than those of HR 95 and HR 98 membranes even at the low operating pressure. In the concentration limit depended on the membranes used, HR membranes operated at 60 bar showed $29.0^{\circ}$Brix, and the time required to reach the limit was 86 min for HR 95 and 71 min for HR 98. In cases of CA membranes run at 30 bar, the juice concentration was linearly increased without the limit, and longer time to reach the same concentration was required in comparison with HR membranes. As the juice concentration was increased, the loss of soluble solids was increased, and the average contents of soluble solids in the permeate passed through HR 95, HR 98, CA 865 and CA 960 were 1.3, 0.5, 7.5 and $2.3^{\circ}$ Brix, respectively, in the juice concentration range of 20.0 -$25.0^{\circ}$ Brix. The lower amounts of sugars, total acid and flavor volatiles were involved in the permeate through HR membranes, especially HR 98 than in the permeate through CA membranes.

Keywords

reverse osmosis membranes;apple juice;pre-concentration