1. Evaluation of Microbial Quality of Raw Goat and Ewe’s Milk Produced in Sabrata, Libya
1Abojnah, Y. S., 2Khatabi, N. A., 1Gnan, S. O., and 3Moncada, M. L.
1University of Tripoli, Tripoli Libya
2School of Science, Academy of Graduate Studies, Tripoli, Libya
3 LSUAgCenter Food Incubator, Louisiana State University Baton Rouge, LA USA.
ABSTRACT:
The objective of this project was to evaluate the microbial quality of the raw goat and ewe’s milk in the region of Sabrata, Libya. One
hundred random samples of bulk tank raw ewe’s and goat’s milk (50 samples each) were collected from different farms in Sabrata, Libya
region. All samples were subjected to microbiological tests which included total plate counts (TPC), total coliform counts, yeast and
mold counts, Staphylococcus aureus, psychrotrophic, thermophilic, proteolytic and lipolytic bacteria counts as well as pH measuring.
There was a significant (P<0.05) differences between all samples analyzed on total plate counts, thermophilic, coliform and lipolytic
bacteria counts. The obtained results showed that the mean TPC log cfu/ml were 6.36 and 4.62 respectively. Psychrotrophic and
thermophilic counts were detected in 90 and 88%; 88 and 76% of the samples with mean values in log cfu/ml of 3.67 and 3.18; 2.79 and
3.56 respectively. Results also indicated that Staphylococcus aureus and coliforms were present in 100 and 100%; 98 and 98% of the
samples with mean values in log cfu/ml 2.82 and 3.28; 3.63 and 3.18 respectively. On the other hand proteolytic and lipolytic bacteria
were present in 100 and 100%; 98 and 94% of the samples with mean values in log cfu/ml 2.88 and 3.17; 2.61 and 2.61 respectively.
Yeast and mold were detected in 88 and 88% of the samples with mean values in log cfu/ml <1.17 and <1.17. The mean values of pH in
all samples analyzed were 6.46 and 6.5. In conclusion, the relatively high microbial count reflecting the poor sanitation and hygienic
practices in the region evaluated.
INTRODUCTION:
World production of milk is forecast to rise to 665 million tons by 2014, representing an average annual increase of 1.5% compared to an
annual average growth during the 1990’s. Milk production is projected to grow in each of the major country grouping (developed,
transitional and developing); however, the largest increment is expected in the developing counties. In these countries, the output of milk
is projected to rise by 71 million tons to reach 293 million tons (FAO, 2013).
Goat and ewe‘s milk owing to its composition has a potentially greater role to play in future human nutrition and medicine than cow’s
milk. Goat and ewe farmer would more readily set up or expand goat enterprise because of the lower capital investments required
concurrent with lower risk. There is a growing demand for unpasteurized goat’s and ewe’s milk and milk products by consumers in
Sabrata, Lybia. The traditional dairy products from goat’s and ewe’s milk are typically made from raw milk with the natural microflora
responsible for enhancing desirable flavor characteristics. So there is a clear need to find out more about the present situation regarding
the milk quality in Sabrata city.
MATERIALS AND METHODS:
RESULTS:
Table 1. Least Square Means for the different indicator microorganisms of the goat’s
and ewe’s milk bulk tanks
CONCLUSIONS:
 Total plate counts, coliform counts and Staphylococcus aureus counts from overall raw goat’s
and ewe’s milk bulk tank samples exceeded maximum limits of the Libya raw milk quality
standards, which it indicates poor quality practices of the milk bulk tanks evaluated in this study.
Indicator Microorganisms
Milk Source
Ewe's milk Goat's milk
Total Plate counts 6.36a 4.62b
Coliform bacteria counts 3.63a 3.18b
Staphylococcus Aureus counts 2.82a 3.28a
Psychrotrophic bacteria counts 3.67a 3.18a
Thermophilic bacteria counts 2.79a 3.56b
Proteolytic bacteria 2.88a 3.17a
Lipolytic bacteria counts 2.61a 2.61a
Yeast and mold counts 1.17a 1.17a
Indicator Microorganisms Positive Samples (%)
Ewe' s milk Goat's milk
Total Plate counts 100 100
Coliform bacteria counts 98 98
Staphylococcus Aureus counts 100 100
Psychrotrophic bacteria counts 90 88
Thermophilic bacteria counts 88 76
Proteolytic bacteria 100 100
Lipolytic bacteria counts 98 94
Yeast and mold counts 88 88
Sample collection from farms
of Sabrata, Lybia
Ewe’s milk
(50 samples)
Goat’s milk
(50 samples)
Sample preparation
(1:9) (milk:saline solution)
Microbiological tests
Total plate count
(TPC)
Total coliforms
Yeasts & Molds
Staphylococcus
aureus
Psychrotrophic
bact.
Thermophilic
bact.
Proteolytic bact.
Lipolytic bact.
Table 2. Positive samples from the different goat’s and ewe’s milk bulk tanks
evaluated in Sabrata region, Libya