Abstract:
This study was designed to evaluate the Hazard Analysis and
Critical Control Points (HACCP) system implemented in yoghurt
processing line from Premier (Daima), Alrawabi and Khartoum dairy
product co- ltd factories (Raira).
The critical control points (CCPs) were identified in the flow
diagram of yoghurt production. The critical control points (CCPs) were
including raw milk, pasteurization, packaging, fermentation and
distribution. Also the control measures, critical limits, monitoring
procedures and corrective action for each CCP were identified.
Also the critical control points were identified during the shelf life
period to know the hazards which may be presented and the chemical and
microbial tests were carried out after first, fourth, seventh and tenth days )
Raira yoghurt was not determined ) and the results were statistically
analyzed.
The results obtained revealed that the pH values of raw milk were
found to be 6.54, 6.40, and 6.65 for Raira, Alrawabi and Daima yoghurt,
respectively. The fat % was found to be 3.75, 3.23 and 3.23 for Raira,
Alrawabi and Daima samples, respectively. The total solids % was 11.46,
16.96, and 15.30 for Raira, Alrawabi and Daima yoghurt, respectively.
All the samples were found to be free from antibiotics and obtained
negative results for alcohol test for identification of the microbial quality.
After pasteurization of milk, the results obtained for pH values
were 6.42, 6.42, and 6.63 for Raira, Alrawabi and Daima yoghurt,
respectively. The total solids % after pasteurization was 14.33, 14.30 and
15.40 for Raira, Alrawabi and Daima yoghurt, respectively.
The microbiological analysis after pasteurization for the three types
of yoghurt revealed that the total bacterial counts were 5.5 x 102 ,
III
1.2 x 103 and 5 x 10 cfu/ ml for Raira, Alrawabi and Daima yoghurt,
respectively. The coliform counts were found to be 1.0, 2.0 and 1.0
cfu/ml for Raira, Alrawabi and Daima yoghurt, respectively.
After packaging, the three factory products showed negative results
for the presence of E.coli, but the coliform counts were found to be 3.0,
8.0 and 4.0 cfu/ml for Raira, Alrawabi and Daima yoghurt, respectively.
The yeasts and moulds were 3.0, 2.0 cfu/ml for Alrawabi and Daima
yoghurt, respectively and were not found in Raira yoghurt.
After fermentation, the pH values were 4.83, 4.53 and 4.90 for
Raira, Alrawabi and Daima yoghurt, respectively.
After the processing operation was finished, some chemical,
physical and microbiological tests were carried out during the shelf life
period. The results obtained for Alrawabi yoghurt for the pH value was
4.70, 4.60, 4.53 and 4.50 after 1st, 4th, 7th and 10th storage periods,
respectively, and fat % was 2.90, 3.0, 3.0 and 3.0 during the four storage
periods, respectively. The temperature was 11.5, 10.0, 9.35 and 10.0°C
during the four storage periods, respectively.
Alrawabi yoghurt showed the absences of coliform after 7th and 10th
days, but in the 1st and 4th days were found to be 10.0 and 7.0cfu/ml,
respectively. Also the product was free from yeasts and moulds in the 4th,
7th and 10th days during the storage periods, but in the 1st day were found
to be 6.0 cfu/ml.
During the four storage periods for Daima yoghurt, the pH was
4.70, 4.50, 4.43 and 4.37 for the 1st, 4th, 7th and 10th days, respectively, and
fat % was 3.03, 2.60, 2.85 and 3.0 during the four storage periods,
respectively, the temperatures was 9.70, 9.30, 9.63 and 9.13°C during the
four storage periods, respectively.
The microbiological analysis of Daima yoghurt revealed absence of
coliform, yeasts and moulds during the four storage periods.