Effect of the amino acid mixture on freeze-drying and preservation of Lactobacillns casei YIT 9018

아미노산 혼합용액이 Lactobacillus casei YIT 9018의 동결건조 및 저장성에 미치는 영향

  • 윤성식 (부천공업전문대학 식품영양과) ;
  • 이해옥 (연세대학교 공과대학 식품공학과) ;
  • 유주현 (연세대학교 공과대학 식품공학과)
  • Published : 1986.10.01

Abstract

This study was attempted to find out effective storage methods of Lactobacillus casei YIT 9018, industrial strain for fermented mil k production, without severe bacterial death and activity deteriorations. The cryoprotective effect of the ammo acid mixture consisting of glycine and DL-g1utamic acid on the test strain were examined and also compared with those other protectants already reported. The apparent protective effect by the amino acid mixture was observed to controls. Both glycine and DL-glutamic acid prevented the freezing death of test strain and his effect of 1. casei YIT 9018 had reached stationary stage in MRS-broth 18h after inoculation. Cells harvested from stationary stage were most resistant to freezing damage. The viability of the test strain was affected by rehydration media and the recovery of viable cells was increased about threefold when amino acid mixture was used for rehydration. The presence of non-fat milk solid (NFMS), sucrose and lactose in amino acid mixture increased viability of the test strain up to 85%. In this case, optimal concentrations of NFMS, sucrose and lactose were 10%, 7.5-10%, 7.5-10%, respectively.

Keywords

Lactobacillus casei YIT 9018;cryoprotective effect;amino acid mixture;glycine;DL-glutamic acid