Shelf Life of Freeze Dried Product of Lactic Acid Bacteria Fermented Food Prepared from Milk or Egg White Powder

우유 또는 난백분말로 만든 젖산균발효식품을 동결건조한 제품의 저장성

  • Ko, Young-Tae (Department of Foods and Nutrition, Duksung Women's University) ;
  • Kang, Jung-Hwa (Department of Foods and Nutrition, Duksung Women's University)
  • 고영태 (덕성여자대학교 식품영양학과) ;
  • 강정화 (덕성여자대학교 식품영양학과)
  • Published : 1999.10.31

Abstract

Freeze dried products of lactic acid bacteria fermented food prepared from milk or egg white powder(EWP) were stored at $28^{\circ}C.\;5^{\circ}C$ and $-18^{\circ}C$ for 20 weeks. Properties of stored, freeze dried product and viable cell count. pH and organoleptic properties of stored, reconstituted product were investigated. (1) The viable cell count of reconstituted milk or EWP product stored at $5^{\circ}C\;or\;-18^{\circ}C$ was not changed markedly. However, the viable cell count of milk or EWP product stored at $28^{\circ}C$ was reduced during storage and it was changed substantially between 4 weeks and 5 weeks. However, pH of all samples stored at three different temperature was not changed. (2) Color of freeze dried product prepared from EWP became clearly brown at 16 weeks. (3) Appearance of reconstituted milk product stored at $5^{\circ}C\;or\;-18^{\circ}C$ for 20 weeks was not changed. However, homogeneity and solubility of reconstituted milk product stored at $28^{\circ}C$ for 20 weeks were reduced. Taste, odor and texture of reconstituted milk product stored at $28^{\circ}C$ for 20 weeks were markedly changed. (4) Viscosity of reconstituted EWP product stored for 20 weeks was slightly reduced. Solubility of reconstituted EWP product stored at $28^{\circ}C$ for 20 weeks was reduced and its taste and odor were markedly changed. Texture of reconstituted EWP product stored at $28^{\circ}C$ became rough.

Keywords

lactic acid bacteria;egg white powder;freeze drying