Effect of Water Extract of Green Tea on the Quality and Shelf Life of Cooked Rice

녹차 물추출물이 쌀밥의 품질 및 저장성 향상에 미치는 효과

  • Roh, Hyun-Jeong (Department of Food and Nutrition, Wonkwang University) ;
  • Shin, Yong-Seo (Department of Agricultural Chemistry, Wonkwang University) ;
  • Lee, Kap-Sang (Department of Agricultural Chemistry, Wonkwang University) ;
  • Shin, Mee-Kyung (Department of Food and Nutrition, Wonkwang University)
  • Published : 1996.06.30

Abstract

We investigated the effect of green tea extract (GTE) on the sensory properties, color value and shelf-life characteristics (pH, titratable acidity and total bacteria count) of cooked rice. Sensory attributes such as taste, flavor and overall acceptability were significantly higher in cooked rices prepared with 500, 1000 ppm of GTE than those of control group (p<0.01) but there was no significant difference among samples (p<0.01) in textural quality. Redness, yellowness and total color difference (${\Delta}E$) were higher when GTE was added. When cooked rice was putrefied, the values of pH, titratable acidity and total bacteria count were about 5.8, 0.3% and $10^8$ cfu/g, respectively. The shelf life of cooked rice was prolonged to 1-2 day by adding 500 and 1000 ppm of GTE as compared to control group.

쌀밥의 저장성을 향상시킬 목적으로 밥물에 녹차 물추출물을 첨가하여 취반하고 쌀밥의 품질특성 및 저장성을 측정하였다. 500, 1000ppm의 녹차 물추출물이 첨가된 쌀밥의 관능성은 전체적인 기호도, 맛 그리고 향기 항목에서 대조구보다 우수하였으나 조직감에서는 1%수준에서 유의적인 차이가 없었다. 색도는 녹차 물추출물 첨가로 인해 L값은 감소하였고 a, b값은 증가하였으며 대조구와 색도차이(${\Delta}E$)는 500, 1000 ppm에서 각각 15.08, 19.41로 매우 컸다. 쌀밥이 부패되었을때 pH는 5.8,적정산도는 0.3%그리고 총세균수는 $10^8\;cfu/g$ 수준이었다. $30^{\circ}C$에서 저장중 대조구에서는 3일만에 변질이 되었으나 녹차 물추출물 500, 1000 ppm첨 가구에서는 각각 4, 5일만에 변질이 되어 저장성이 $1{\sim}2$일 정도 연장되는 것으로 나타났다.

Keywords