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Effects of pasteurisation
on survival patterns of microorganisms and vitamin C
retention in kunun-zaki
Egbere, O. J.1*, Pam, K. V.1,
Adesheyan, K. D.1, A'Kadir, T.2 and
Oyero, S. K.3
1Department
of Microbiology, University of Jos, Nigeria.
2Department
of Chemical Pathology, College of Health Technology, Zawan,
Nigeria.
3Histopathology
Department, Jos University Teaching Hospital, P.M.B. 2076,
Jos, Nigeria.
*Corresponding author. E-mail:
egbereo@yahoo.com.
Tel: 08033646268.
Accepted
5 September, 2008 |
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The effects of pasteurisation on the survival patterns of the
microflora as well as vitamin C retention in kunun-zaki
fortified with vitamin C was syudied. A laboratory sorghum
based kunun–zaki was fortified with 90 mg/l of vitamin C.
The content was subjected to pasteurisation at 70oC
for different time intervals ranging from 0 - 30 min.
Samples of the beverage were then taken at 5 min intervals
during pasteurisation and were analysed for microbial load
and residual vitamin C content by 2,6-dichloroindophenol
titration method. The results showed that there was a
gradual decline in vitamin C retention and steep decline in
the microbial load reduction during pasteurisation. The
result also showed that at the 20th min of
pasteurisation, 80% of microbial isolates had been
eliminated leaving only Bacillus Subtilis and
Saccharomyces cerevisiae as the surviving organisms. The
D70 -value of the most heat resistant organism
B. subtilis was found to be 6.5 min.
Key
words:
Kunun-zaki, pasteurisation, D-value, vitamin C, Bacillus
subtilis. |
