Effects of pasteurisation on survival patterns of microorganisms and vitamin C retention in kunun-zaki

  • OJ Egbere
  • KV Pam
  • KD Adesheyan
  • T A'Kadir
  • SK Oyero
Keywords: Kunun-zaki, pasteurisation, D-value, vitamin C, Bacillus subtilis.


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.

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eISSN: 1684-5315