Dr. John Holah - Articles and news items

Holchem’s Dr John Holah becomes Honorary Professor

Featured news  •  15 June 2016  •  Victoria White, Digital Content Producer

John Holah, Technical Director of Holchem, has become an Honorary Professor of Food Safety at Cardiff Metropolitan University…

Quaternary ammonium compound maximum residue levels

Issue 6 2014  •  23 December 2014  •  John Holah, Jim Taylour and Steven Ackers Holchem Laboratories Ltd

In Europe, disinfectants (biocides) used in the food industry are controlled by a range of legislation, but two are key in determining the level of disinfectant that can be taken up by foodstuffs after the disinfectant’s legitimate use. Regulation (EC) No 396/20051 on maximum residue levels of pesticides in or on food and feed of plant and animal origin governs the use of pesticide residues…

HACCP: The rise of the prerequisites

Issue 6 2011  •  4 January 2012  •  John Holah and Edyta Margas, Campden BRI and Robert Hagburg, Benjamin Warren, Judy Fraser-Heaps and Sara Mortimore, Land O’Lakes

This article introduces concepts and ideas about the nature and potential control of microbiological cross-contamination in a food manufacturing environment. The concepts and opinions shared do not necessarily represent the policies and/or programs used by the companies represented by the authors.

Microbiological cross-contamination has been a contributing factor to several well-documented outbreaks of foodborne illness1,2. In most HACCP or other hazard analysis-based food safety systems, cross contamination is controlled and managed predominately by prerequisite programs (PRPs). PRPs can be defined as the measures that provide the basic environmental and operating conditions in a food operation that are necessary for the production of safe and wholesome foods3, such as cleaning and disinfection and personnel hygiene. The implementation of an appropriate PRP is also seen as the foundation on which a good HACCP plan is built and there are many examples of best practice to follow for each prerequisite (PR) at an international level4, via retailers requirements5 or from recognised food research bodies6-8 or trade associations9,10.

There is little information, however, on how to align the use of specific PRs to control actual routes of cross-contamination in food pro – cessing plants.

Whole room disinfection – potential for environmental pathogen control?

Issue 5 2010  •  5 November 2010  •  Alicja Malinowska & John Holah, Campden BRI

To meet retailer, customer and consumer expectations, there are increasing demands within the food industry for higher standards of microorganism control in food production environments. Traditional approaches such as cleaning and disinfection regimes have been targeting specific sites within the processing environment to control contamination. Such sites might include food production equipment, where much of the rest of the processing area is not routinely decontaminated.

To sustain day-to-day control of pathogens, this targeted cleaning and disinfection approach is adequate, but does not eliminate all microorganisms. Previous research at Campden BRI has demonstrated that microbial strains, including pathogens, can become persistent in food factories and survive for several years1,2.

Hygienic design of novel processing equipment

Issue 5 2010  •  4 November 2010  •  Edyta Margas & John Holah, Campden BRI and Alexander Milanov & Lilia Ahrné, SIK

The hygienic design of food processing equipment is a critical factor in determining the quality and safety of foods produced. It involves the selection of suitable materials of construction, their fabrication into a functional piece of equipment, the ability of constructed equipment to produce food hygienically and the maintenance of hygienic conditions throughout the equipment’s working life. There is a significant amount of guidance and information available on the principles of hygienic design for traditional food processing equipment (from the European Hygienic Engineering Design Group; www.EHEDG.org), but the nature of NP techniques such as High Pressure Processing (HPP) and Pulsed Electric Field (PEF) may impose other additional stresses on the equipment surfaces, their construction materials and their fabrication.

Mirror, mirror on the wall, who’s the most hygienic of them all?

Featured news  •  27 November 2009  •  Dr. John Holah, Head of Food Hygiene, Campden BRI

Whilst we believe that food safety is a major issue in the food industry, it rarely features in the press; hygiene in the healthcare sector, particularly related to the control of healthcare acquired infections (HAI’s), is, however, rarely out of the media. With the media attention focused on healthcare hygiene, has the clinical sector developed technologies that could be of benefit to the food industry? Who is the most hygienic of all?