TITLE:
Biocontamination Risk of Staphylococcus aureus in Dairy Manufacturing Presence of Two Types of UHT Milk
AUTHORS:
Safae Tankiouine, Hafida Zahir, Mourad El Goulli, Kaoutar El Fazazi, Abdelwahid Assaidi, Taoufik Hakim, Mostafa El Louali, Hassan Latrache
KEYWORDS:
Physicochemical Properties, Skimmed UHT Milk, Whole UHT Milk, Contact Angle, Adhesion, Staphylococcus aureus
JOURNAL NAME:
Food and Nutrition Sciences,
Vol.11 No.8,
August
25,
2020
ABSTRACT: The biofilm formation on equipment surfaces in dairy manufacturing is a
major concern for industry and consumers alike, which may affect the safety and
quality of dairy products. In order to identify the bio-contamination risk of materials
commonly used in dairy manufacturing, adhesion of Staphylococcus aureus on
glass coated by two kinds of UHT milk (whole milk and skimmed milk) was
investigated. It is known that adhesion is mainly governed by surface
physicochemical properties, for that, the effect of milk components on physicochemical
properties of glass and bacterial surfaces were exanimated through contact
angle measurements. MATLAB software was used to evaluate the ability of S. aureus adhesion on glass. The
hydrophobic quantitative and electron acceptor characteristics of the glass
appear to increase with the presence of fat in milk, while its electron donor
property decreases
with this component. The percentage of occupied surface of untreated glass was
more important than in treated surfaces for 50% of the strains studied. As well, the percentage of
occupied surface by bacterial strains in untreated glass by skimmed milk is
generally more important compared to the whole milk. Therefore, the risk of
bio-contamination of untreated glass is more favorable for bacteria cultured in
skimmed milk compared to these in whole milk but the bio-contamination risk on
covered glass by milk is not milk dependent and is strain dependent.