General Microbiological Quality of Ice Cream and Ice Pop Sold in Gaborone, Botswana

The study was aimed at investigating the microbial quality of ice cream and ice pop sold in Gaborone. From the study, a variety of microorganisms were isolated. The population of bacteria was found to increase from the open ice cream samples while the pre-packed ice cream had a lower population of bacteria. The types of microorganisms were both mesophilic and psychrotrophic. The population of mesophiles in open ice cream ranged between 3.30 log 10 CFU/g and 6.78 log 10 CFU/g. The psychrotrophs in the same food samples ranged between 2.0 log 10 CFU/g and 6.70 log 10 CFU/g. These values were found to exceed the acceptable microbiological standard. The results for packed ice cream had lower counts of microbes (ranging between 2.48 and 5.48 log 10 CFU/g), with only one sample out of 150 having a log count above the microbiological standard of 4.0 log 10 CFU/g. Address for correspondence: E-mail: [email protected] INTRODUCTION Ice cream and other edible ices can be referred to as frozen dairy desserts (Silliker et al. 1980). These include among others ice cream, sherbet, ices and ice milk. Ice cream contains mainly milk fat (about 10-16%; depending on the standard), non-fat milk solids (about 9-12%), sugar (sucrose) (9-12%), water (55 64%) and 0.200.50% stabiliser and/or emulsifier (Silliker et al. 1980; Pick et al. 1990; Potter and Hotchkiss 1995). Fruits, nuts, candies and syrups are optionally added into ice cream for flavour enrichment. It is sold in packages or in open containers at retail outlets/ice cream parlours, the open variety being distributed manually in scoops, cones, or sundaes across the counter (Çaðlayanlar et al. 2009). During production, transportation and storage, it may become contaminated with several microorganisms. Microorganisms are transmissible to humans through milk and milk products (Vasavada 1988; Tomislav et al. 2012). Some of the diseases associated with pathogenic bacteria associated with the dairy industry are tuberculosis, brucellosis diphtheria, scarlet fever, Q-fever and most commonly gastroenteritis (Vasavada 1988; Miettinen et al. 1998; Warke et al. 1999). According to the World Health Organisation (1988), national surveillance of milk and milk products conducted around the world have revealed that generally 5% of ice cream produced is contaminated. The pasteurisation temperatures that are currently used are sufficient to destroy the most heat-resistant of the non-spore forming pathogenic organisms such as Mycobacterium tuberculosis and Coxiella burnetti (Adams and Moss 1995). The micro-organisms that can stand pasteurisation are mainly the gram positive spore-forming bacteria and thermoduric non-spore-formers. The rest of gram negative and gram positive non-spore forming bacteria, yeasts and moulds are destroyed by pasteurisation (Jay 1996). The microflora of these frozen products before pasteurisation is mainly determined by ingredients used in making the products (Roberts et al. 1998). These usually include Micrococcus species, Bacillus subtilis and Lactobacillus casei that withstand pasteurisation (Roberts et al. 1998; Silliker et al. 1980). Under modern production conditions, thermoduric psychrotrophic microorganisms and particularly Bacillus species, determine the shelf life of pasteurised milk products during extended storage though (Frank et al. 1993; GarciaArmesto and Sutherland 1996). This improved pre-packaging treatment has therefore reduced the microbiological load in dairy products. The microbial count usually goes down to below 80 per ml after the ice cream mix has gone through proper or adequate pasteurisation which is usu© Kamla-Raj 2013 Ethno Med, 7(3): 217-226 (2013)