Microbial and chemical measurements of fermented camel milk ‘gariss

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Date
2015-04-01
Authors
Awad Hassan, Rihab
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UOFK
Abstract
present study was carried out to assess the chemical composition and microbial content of gariss samples (fermented camels milk) collected from nomadic herders (Butana area) and transhumance herders (Eastern Nile- Khartoum North). The results indicated that the mean level of total solids, fat, ash and lactose contents in transhumance herders gariss samples were found to be 11.29± 1.401%, 4.85± 0.664%, 1.3± 2.166% and 3.46± 1.12%, respectively. These values were found to be higher than the values, which recorded for the nomadic herders gariss samples (9.81± 2.31,% total solids, 3.46± 1.17%fat, 0.87± 0.13% ash and 3.2± 1.63% lactose). However, protein content revealed high mean values (2.5831± 0.6887%) in nomadic samples compared to transhumance gariss samples (2.3237± 0.5906%). Lower pH values were recorded for gariss samples obtained from transhumance herders (3.4143± 1.1224), while high acidity values were recorded for nomadic gariss samples (2.2443± 0.6766%). The results indicated significant variations between gariss collected samples in pH and acidity (P< 0.001) and lactose (P< 0.05). Also, significant variations between nomadic and transhumance gariss samples were found for fat content (P< 0.01). The microbial content revealed low levels of total bacterial count in transhumance gariss samples (log107.26± 0.493) compared to nomadic gariss samples (log107.56± 0.228). Moreover, log. yeast count was recorded to be higher in nomadic gariss samples (log107.02± 0.298) compared to transhumance (log106.99± 0.122), in addition to its highest count among the other species found in the collected gariss samples. The log10. streptococcus spp. count was found to be higher in nomadic camel herders samples (log10 6.85± 0.331) than transhumance samples(log10 6.47± 0.34) Streptococcus lactis (12, 50%) and Str. lactis sub spp. diacetylactis (12, 50%) were the two species of streptococci, which were isolated from the collected samples. While Lact. plantarum (8, 33.3%), Lact. brevis (4, 16.66%), Lact. casei (4, 16.66%), Lact. leichmanii (4, 16.66%), Lact. acidophilus (1, 4.16%) and Lact. fermentum (3, 12.5%) were the were identified from the collected samples. In the other trails which include the processing of gariss in the laboratory. The objective was to investigate the effect of pasteurization and storage conditions on the chemical and microbial content of the processed samples. The inoculated gariss, which used as a gariss culture, was consisted of 2.65% fat, 3.13% protein, 7.37% total solids, 0.51% ash and 1.09% lactose. The acidity and pH of the starter culture were found to be 2.49% and 3.8, respectively. The total bacterial counts, lactobacillus spp count and yeast count of the gariss culture were found to be 1.8×106, 4.9×106 and 4.9×106 cfu/ ml, respectively. However, the fresh camel’s milk collected for processing was found to contain 4.3% fat, 2.25% protein, 9.64% total solids, 0.97% ash and 2.12% lactose. The acidity and pH of the fresh camel milk were found to be 0.12% and 6.4, respectively. The non pasteurized gariss samples were found to attain high level of total solids, fat, protein and ash than the pasteurized fermented milk at beginning of the storage period. Moreover, fat and protein content of the processed gariss samples were found to be significantly affected (P< 0.05) by the pasteurization and storage conditions. Moreover, the mean levels of ash revealed significant differences (P< 0.05) between the pasteurized samples. Also the storage duration revealed significant variations (P< 0.05) for ash content. The pH value and acidity levels were found to be significantly affected (P< 0.05) by pasteurization and storage temperatures. The pasteurization and storage periods revealed significant variations (P< 0.05) for total bacteria count. Lactobacillus spp. count was affected significantly (P< 0.05) by the incubation temperatures. Also the storage conditions (temperature and duration) revealed significant differences (P< 0.05) between the processed samples for yeast count. The processed samples were found to withstand the storage condition up to 234 hours. The present study concluded that the variations between the areas and management systems had an observed effects on the chemical and microbial contents of gariss. Also the chemical composition and microbial contents were affected by pasteurization and storage conditions (temperatures and storage periods). Hence the study recommended that more investigations are needed on the microbiology, nutritive values and medicinal properties of camel’s milk products. Moreover, in order to contribute in food security, organization of collection and processing centres are also needed.
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Microbial and chemical measurements of fermented camel milk ‘gariss’
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