Evaluation of processing methods and microbial analysis of Pito (an African indigenous beer), at selected production sites in Ghana
Pito is an African indigenous sorghum-beer brewed on household basis. The brewery processes in assuring the quality of the drink have not been clearly defined nor studied. To evaluate the brewery processes at selected pito brewery sites in Ghana, the study adopted oral interviews/survey, observations and laboratory tests that sought to elucidate the presence of aflatoxins in the drink and to quantify and identify the yeasts and moulds present. Qualitative coliform tests were also performed on the drink to ascertain the hygienic conditions of the brewery sites. Pito samples were taken from selected centres at dominant pito producing areas; Upper West Region (Nandom), Northern Region (Tamale) and Ashanti Region (Kumasi). The survey results revealed there were currently five processing methods being used to brew the drink in the selected regions. The processing methods were similar but sequentially different. Pito samples from Kumasi showed the highest moulds contamination of 3.7 x 10 3 ± 0.424 and 1.3 x 10 3 ± 0.424 at Ayeduase and Tech-Junction respectively compared to all the other samples. The moulds identified in the drink were Aspergillus clavatus, Mucor hiemalis, Cladosporium sphaerospemum and Cladosporium herbarum. Saccharomyces cerevisiae, Debaryomyces hansenii and Pichia anomala were also isolated as the yeast species in the drink. There was no aflatoxin in all the beverage samples collected but malted grains samples collected from Tech-Junction in Kumasi showed aflatoxin concentration of 9.58 ppb. Coliforms test using violet red bile agar were also negative for all the samples.
A thesis submitted to the Department of Food Science and Technology, College of Science in partial fulfilment of the requirements for the degree of Masters of Science in Food Science and Technology.