Full Length Research Paper

Effect of storage conditions on the shelf life of locally distilled liquor (Akpeteshie)

Zakpaa, H. D.*, Mak-Mensah, E. E., and Avio, O. A.

Department of Biochemistry and Biotechnology, Faculty of Biosciences, College of Science, Kwame Nkrumah University of Science and Technology, Private Mail Bag, Kumasi, Ghana.

*Corresponding author. E-mail: hzakpaa@hotmail.com.

Accepted 30 December, 2009

   Abstract

Locally distilled liquor (Akpeteshie) is a beverage which is widely consumed in Ghana. It is produced from different raw materials. The purpose of this research was to determine the presence and levels of certain contaminants in akpeteshie from the various sources and to determine effects of ambient temperature, refrigeration, pasteurization and pasteurization in combination with low temperature for the liquor stored for seven weeks. The contaminant microorganisms are spore forming gram positive Bacillus spp., responsible for converting alcohol to acetic acid. Total viable count (TVC) reached 25, 120 cfu/100 ml during the first week of storage, under room temperature in the most contaminated sample and thereafter, increased till the end of the storage period. Storage under the other conditions drastically retarded microbial growth. pH decreased from 5.0 to 2.7 at the end of storage period while the titrable acidity increased from 1.10 to 1.63. However, the pH and titrable acidity varied at slower rates in samples stored under other conditions. An increase from 0.02 to 0.04 was recorded for the acetic acid content of S2 (sample obtained from the second production site in the district; New Town). The presence of acetic acid, iron and copper metals were detected in all the samples. The study therefore concludes that the various storage conditions had an appreciable effect on the quality of akpeteshie in the order; storage at room temperature followed by the refrigeration, pasteurization, then pasteurization in combination with refrigeration in increasing order of effect and that akpeteshie pasteurized and refrigerated is the best for consumption.

Key words: Akpeteshie, ambient temperature, Ghana, refrigeration, pasteurization.