Color Changes in Clarified Fruit and Vegetable Juices by Mixing Ratios

  • Lee, Jun-Ho (Division of Food, Biological and Chemical Engineering, Taegu University) ;
  • Park, Yong-Hee (Department of Food Science and Technology, Kyungpook National University)
  • Published : 2000.12.01

Abstract

Clarified fruit and vegetable juices (apple, carrot and tangerine) were produced using ultrafiltration and their color change due to the mixing ratio were evaluated. clarification was carried out by passing he supernatant of extracted juice through a filter and also by using a membrane of molecular weight cut-off 10,000 Daltons to obtain the juice ultrafiltrates. The mixing ratio between apple and carrot juices was kept constant at 1:1 while increasing the amount of tangerine juice according to 10, 20, 30, 40 and 50% an stored at 4$^{\circ}C$ prior to the color measurement. Hue angle ({TEX}$h_{ab}${/TEX}) and {TEX}$L^{*}${/TEX}-value increased as the tangerine mixing ratio increased. The color difference indicated by ΔE-value also increased as the amount of tangerine increased indicating that the color of the mixed juice became pale and the changes were slight but distinctive. On the other hand, chroma ({TEX}$C^{*}${/TEX}), {TEX}$La{*}${/TEX}- and {TEX}$b^{*}${/TEX}-values decreased as the tangerine mixing ratio increased indicating that the color of the mixed juice became slightly more grayish and the samples were becoming les yellow. A simple mathematical model to predict each color characteristic is proposed.

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