The growth and survival of food-borne pathogens in sweet and fermenting brewers' wort
- Authors: Menz, Garry , Vriesekoop, Frank , Zarei, Mehdi , Zhu, Bofei , Aldred, Peter
- Date: 2010
- Type: Text , Journal article
- Relation: International Journal of Food Microbiology Vol. 140, no. 1 (2010), p. 19-25
- Full Text: false
- Reviewed:
- Description: The aim of this study was to investigate the factors affecting the survival and growth of four food-borne pathogens (Escherichia coli O157:H7, Salmonella Typhimurium, Listeria monocytogenes, and Staphylococcus aureus) in sweet and fermenting brewery wort. The Gram-negative pathogens (E. coli and Salm. Typhimurium) were capable of growth during the initial stages of fermentation in hopped wort, although they were quickly inactivated when added during the later stages of fermentation. When the wort was left unpitched, the two Gram-negative pathogens grew unabated. Pathogen growth and survival was enhanced as the pH was increased, and as both the ethanol and original gravity were decreased. Although having no effect on the Gram-negative pathogens, low levels of hop iso-
- Description: 2003008146
Changes in the prefermentation static washing regime of Kalamata olives affect the fermentation profile
- Authors: Menz, Garry , Bradbury, Mark , Vriesekoop, Frank
- Date: 2008
- Type: Text , Journal article
- Relation: Food Technology and Biotechnology Vol. 46, no. 3 (Jul-Sep 2008), p. 341-345
- Full Text:
- Reviewed:
- Description: Traditional methods of naturally black olive production employ a series of static washings prior to fermentation. This work investigates the static washings and the effects they have on the subsequent spontaneous fermentation of Kalamata olives. Significant quantities of organic carbonaceous material, including phenolic compounds, were removed during the static washings. The rate of removal peaked after four static washings, and then declined. Bacteria (including lactic acid bacteria) and yeast were found to be present in high numbers throughout the static washings. An increase in the number of static washings resulted in the removal of inhibitory phenolic compounds. This led to a reduction in the lag phase and an increase in the specific growth rate for both the yeast and lactic acid bacteria during the subsequent spontaneous fermentations. However, an increased incidence of spoilage moulds was observed in the fermentations when the olives underwent thirteen static washings.
- Description: C1