Effects of Extractants on the Characteristic of Soluble Dietary Fiber from Apple Pomace

추출용매가 수용성 사과박 식이섬유의 특성에 미치는 영향

  • 김효중 ((주)한국야쿠르트 중앙연구소) ;
  • 허재관 ((주)한국야쿠르트 중앙연구소) ;
  • 허철성 ((주)한국야쿠르트 중앙연구소) ;
  • 백영진 ((주)한국야쿠르트 중앙연구소)
  • Published : 2001.04.30

Abstract

The dietary fiber was extracted from apple pomace with various concentrations of acidic, alkaline solvents and water in $24.4{\sim}29.3%$ yield. The extractions of water-soluble dietary fiber with acidic(6.85%) and alkaline solvent(6.55%) were more effective than the water extraction(6.0%). The higher extraction yield was obtained with increased concentration of acidic or alkaline solvents. The content of galacturonic acid was higher in the order, 0.01 M HCl(77.5%)>0.05 M HCl(76.8%)>$H_2O(76.1%)$>0.05 M NaOH(73.8%)> 0.01 M NaOH(69.0%) and the extraction with acidic solvent showed the highest pectin yield. The color value increased by extraction with solvent in higher concentration. And at equal concentration, the color value of alkaline extract was higher than that of acidic exctract. There was no relationship between the color value and the extraction yield of dietary fiber. In the investigation on the rheological properties, the shear stress increased in proportion to galacturonic acid contents. While water-soluble dietary fiber extracted with acid and water represented Newtonian rheological properties, the alkaline extract was inclined to have converting property from pseudoplastic to Bingham pseudoplastic with increment of alkaline concentration. In the studies on the time-dependence of apparent viscosity, the thixotropic property with hysteresis loop was observed in alkaline extract.

Keywords

apple pomace;yield;color;galacturonic acid;rheological property