Effect of skimmed milk and its fractions on the inactivation of Escherichia coli K12 by high hydrostatic pressure treatment.
We investigated the effects of skimmed milk and its protein fractions (casein, whey, globulin, and albumin) on the injury and inactivation of Escherichia coli K-12 by high hydrostatic pressure (HHP) treatment. The protective effect of skimmed milk on HHP-mediated inactivation and injury of E. coli increased with increases in the skimmed milk concentration. However, protein fractions derived from skimmed milk did not exhibit this protective effect. Microscopy analysis by DAPI/PI staining indicated that some cells were localized in the solid portion of skimmed milk, and some of these cells were alive. The coagulated fraction derived from the autoclaved whey fraction also showed a significant protective effect. We speculate that the solid portion in skimmed milk could provide the protective effect to bacterial cells.
Narisawa
Naoki
N
Department of Food Science and Technology, College of Bioresource Sciences, Nihon University, Kameino 1866, Fujisawa, Kanagawa 252-8510, Japan.
Furukawa
Soichi
S
Kawarai
Taketo
T
Ohishi
Kazuya
K
Kanda
Shino
S
Kimijima
Kana
K
Negishi
Shiro
S
Ogihara
Hirokazu
H
Yamasaki
Makari
M
D000818:Animals; D002417:Cattle; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D048168:Escherichia coli K12 / Q000254:growth & development*; D005506:Food Contamination / Q000032:analysis / Q000517:prevention & control*; D005516:Food Microbiology; D006801:Humans; D006874:Hydrostatic Pressure; D008892:Milk / Q000382:microbiology*; D008894:Milk Proteins / Q000378:metabolism
D008894:Milk Proteins