Exploring microbiological standards and quality attributes of Karish cheese from Egypt

Abstract

Some traditional fermented dairy products like Egyptian Karish cheese and traditional fermented milk 
(Laban Zeer) are manufactured in farmhouses following traditional techniques using raw milk without 
heat treatment or addition of selected starter cultures, these products are generally designed as 
“artisanal”. The representative Karish samples were analyzed for their content of total microbial, 
Enterobacteriaceae, yeast, molds, Staphylococci coagulase positive, Salmonella spp., Listeria spp., in 
addition to detection of Bacillus cereus, Listeria monocytogenes, Clostridium perfringens and 
Campylobacter spp. using classical methods. The physico-chemical properties of collected samples 
showed that the average of protein, fat, moisture and acidity were in accepted range with that reported 
in literatures and Egyptian standard. Some lactic acid bacteria (Lactococcus lactis supsp. lactis, 
Lactobacillus delbrueckii subsp. lactis and Enterococcus feacium) were isolated and identified from 
fresh karish cheese using classical methods followed by rep-PCR. Lactococcus garvieae was detected 
in fresh samples using TTGE but could not be detected using classical methods. The results of 
microbiological analysis showed the presence of high numbers of Enterobacteriaceae that ranged from 
log10 2.6 cfu/g to log10 3.5 cfu/g, Bacillus ssp. ranged from log10 4.2 cfu/g to log 10 5.6 cfu/g, 
Staphylococci counts are ranged from log10 1.8 cfu/g to log10 2.7 cfu/g, faecal enterococci count ranged 
from log10 3.5 cfu/g to log10 5.8 cfu/g. Yeasts and molds count ranged from log10 2.7 cfu/g to log10 3.5 
cfu/g. B. cereus, L. monocytogenes, C. perfringens, Shigella, Salmonella, Escherichia coli β
glucuronidase positive and Campylobacter spp. were not detected in all the examined samples. The 
count of undesirable microorganisms indicated the poor hygienic practice of traditional Karish cheese 
production; starting with using poor quality of raw milk and processing under uncontrolled 
environments. This would require using clean raw milk, controlled manufacturing steps and selection of 
the appropriate starter culture for the fermentation.