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Oil‐in‐Water Emulsion as a Model System to Study the Growth of Escherichia coli O157:H7 in a Heterogeneous Food System
Author(s) -
Prachaiyo P.,
Mclandsborough L.A.
Publication year - 2003
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1365-2621.2003.tb08281.x
Subject(s) - hexadecane , escherichia coli , emulsion , food science , chemistry , chromatography , bacterial growth , biology , bacteria , biochemistry , organic chemistry , genetics , gene
Oil‐in‐water emulsions (hexadecane, minimal media [M9], and Tween 20) were used as model system to study the growth of Escherichia coli O157:H7. Stationary‐phase cell density decreased as the hexadecane concentration was increased (0%, 5%, 20%, and 40% [w/v]) and biphasic growth was observed in 40% emulsions supplemented with 0.4% glucose. Thin aggregate fimbriae (curli) were observed using SEM, and a greater percentage (Ps <0.001) of curli‐producing colonies were isolated from 40% emulsions. Heat resistance (55 °C) of emulsion‐grown cells was greater than broth‐grown cells, indicating that growth and physiology under heterogeneous conditions differ from cells grown in liquid.