African Journal of Biotechnology Vol. 9(10), pp. 1499-1509, 8 March, 2010 Available online at http://www.academicjournals.org/AJB DOI: 10.5897/AJB09.1001 ISSN 1684–5315 © 2010 Academic Journals 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. Accepted 30 December, 2009 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. INTRODUCTION Traditional alcoholic beverages have been consumed in sign of prestige in pre-colonial Ghana and as such, a Ghana and other West African communities for centuries. behavior controlled by the elders and the politically Locally distilled liquor, also known as Akpeteshie in powerful. Women did not consume alcohol; young men Ghana and Ogogoro in Nigeria, is a spirit drink distilled drank rarely and then only as a result of the beneficence from palm wine (Odeyemi, 1980). This drink is of historical of the rich and the powerful (Akyeapong, 1996). significance in Ghana and Nigeria because, as a local There is a simple way of making distilled liquor without gin, colonial administrators barred it in an attempt to requiring a special monitoring system but this gives a control the West African liquor trade in the early part of relatively short shelf life period as compared to the the last century (Isidore, 2001). industrially prepared liquors (Odeyemi, 1980). Akpeteshie is Palm wine was originally the drink of choice in southern essentially an unflavoured alcohol distillate. The storage Ghana, replaced by rum and schnapps during the period materials as well as the conditions affect its alcohol of the slave trade (Akyeapong, 1996). Men, thus, have strength with time. The beverage is regarded “flat” if it come to favor distilled spirits, seen as “hot” or “strong,” loses its sharp strength. The Akpeteshie has a relatively over palm wine or beer. Drinking distilled spirits was a short shelf life period as compared to the industrially prepared liquors. It can however be aged in order to improve its flavor as well as aesthetic appeal. This is done by storing in the presence of certain plant products *Corresponding author. E-mail: [email protected]. like the roots of some plants. This usually imparts 1500 Afr. J. Biotechnol. a light yellow or dark brown colour to the liquor and this is Research on the levels of contamination of Akpeteshie popularly known as “bitters”. The bitters are known to by product content levels and microbes is essential to have some medicinal abilities depending on the type of design better methods for its production and to yield im- plant product used during ageing. Apart from the slight proved distilled liquors of greater value that will offer com- differences in flavour, Akpeteshie produced from the petition to the industrially produced ones on the market. different raw materials contain varying levels of ethanol, In recent years, there has been the establishment of aldehydes, methanol, higher alcohols (fusel oils), total several local distilleries in the country which employ un- and volatile acids as well as solids. Pharmacologically, it scientific and crude methods of producing spirits and as is known that certain critical levels of these components such have flooded the local market with dangerous are toxic to human health. products with low shelf life. An improvement of these The production of Akpeteshie was legalized by the spirits is necessary since they are being overtaken by the Government of the first Republic of Ghana since it was industrially distilled liquors which are of high quality, not allowed to be produced by the then colonial adminis- nicely packaged and are less dangerous with high shelf tration during the Gold Coast era with the view that the life. As a result, it has become essential for the analysis spirits may contain toxic alcoholic components due to of locally distilled liquors to be carried out. A qualitative lack of scientific quality control (Obot, 2000). Akpeteshie study of Akpeteshie in the northwestern region of Ghana is distilled from fermented palm wine or sugar-cane juice found that consuming this traditional Gin was on the rise and require a simple apparatus of two tins (usually four- among both men and women (LuGinaah and Dakubo, gallon kerosene tins) and copper tubing. The standar- 2003). dized alcohol strength of Akpeteshie today is between 40 There is not a single large scale ethanol distilling indus- and 50% by volume (Akyeapong, 1996). Akpeteshie pro- try in Ghana. The distilleries in the country basically buy duction, however, has seen no technological advance- pure ethanol from the large scale distilling countries like ment since the legalization of its production. The methods U.S.A., Germany etc. (Paramount Distilleries, Kumasi). employed in its distillation, collection, ageing, preservation They then mix the pure ethanol with distilled water under and ensuring shelf life stability as well as its bottling have very hygienic conditions to produce the various kinds of not been well taken care of resulting in its low economic industrially manufactured liquors in the country (Multhauf, value as compared to the industrially made liquor like 1993). Gin. Problems relative to Akpeteshie properties and The main aim of the investigation was therefore, to characteristics such as flavour, colour, aroma and storage analyze and establish the levels of the potentially harmful conditions with time also pertain to other alcoholic bever- components of Akpeteshie, as specified by the Ghana ages in general. The different liquor-making practices and Standards Board and their effects on shelf life in relation other important factors bear substantially on particular to the processes locally employed in its production. problems in relation to the liquors which are produced by According to the Ghana Standards Board specifications, traditional methods. For example, the industrial liquors in Akpeteshie should contain no volatile acid (European the country have had particular success with the Commission, 2000). appealing characteristics like flavour, colour, aroma and This research seeks to determine the microbial type high shelf life they exhibit since the methods used in their and load of Akpeteshie and how they change with time production are technologically controlled and improved. and to determine the levels of some contaminants that Akpeteshie production as conducted by most traditional pose health hazards if present at high levels, for methods does not meet the required standards set by the example, methanol, Fe 2+, Pb 2+. Ghana Standards Boards (Table 1). The final product is mostly contaminated by the combined action of various unacceptable levels of component substances like fusel MATERIALS AND METHODS oils resulting from inefficient distillation processes and the Sample collection presence of some acid and alcohol tolerant species of moulds and bacteria resulting from unhygienic methods Akpeteshie samples were obtained, on the same day, from three of liquor production. Some of these organic substances different production sites at Kona in the Efigyasekyere district of the decompose and along with the products of metabolism Ashanti Region. The alcohol samples to be tested were put in 500 produced by some of these microbes impart off flavours ml plastic containers that had been sterilized with alcohol (80% v/w) and cause spoilage of the liquor leading to a product of under conditions that excluded contamination from external sources. low quality and shelf life stability. Despite all the above Three lots from each sample were labeled in 3 groups as sample mentioned setbacks, very little effort has been made to 1 (S1) from site 1 (Kona Habitat), sample (S2) from site 2 (New ascertain whether, through improved production practices Town) and sample 3 (S3) from site 3 (Kona Market), respectively, or by various treatment procedures, these characteristics based on the source of purchase of the mother Akpeteshie sample. of Akpeteshie can be eliminated or at least reduced to a Each sample lot was then grouped into four based upon various storage conditions: Akpeteshie stored at room temperature, point where it would have improved taste and stability pasteurized Akpeteshie, refrigerated Akpeteshie and Akpeteshie characteristics.