Water availability and the survival of Salmonella typhimurium in porous systems

被引:46
作者
Hills, BP
Manning, CE
Ridge, Y
Brocklehurst, T
机构
[1] Institute of Food Research, Colney, Norwich NR4 7UA, Norwich Research Park
关键词
water activity; Salmonella; porous foods; recovery; growth; NMR;
D O I
10.1016/S0168-1605(97)01265-8
中图分类号
TS2 [食品工业];
学科分类号
0832 ;
摘要
The survival of Salmonella Typhimurium LT2 in randomly packed beds of glass beads, microporous silica particles and Sephadex microspheres is examined. It is shown that the decrease in the percentage cell recovery in these porous materials at reduced water content is not correlated with the global water activity as determined by conventional vapour pressure measurements but rather with the osmotic shock induced by the sudden redistribution of water and air among the microscopic pores in the matrix surrounding the cells. For this reason the bacterial survival and growth data correlates best with physical measurements, such as NMR and electrical conductivity, which are sensitive to the microscopic air-water distribution. The implications of this observation in food safety and preservation are discussed. (C) 1997 Elsevier Science B.V.
引用
收藏
页码:187 / 198
页数:12
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