Project Abstract

Abstract
Yoghurt is a popular dairy product consumed worldwide due to its taste and health benefits. However, microbial contamination of yoghurt can lead to various health risks for consumers. This study aimed to investigate the prevalence of microbial contamination in yoghurt samples collected from different sources. A total of 100 yoghurt samples were analyzed for the presence of bacteria, yeasts, and molds. The results revealed that microbial contamination was present in a significant number of yoghurt samples, with bacteria being the most predominant contaminants. The most common bacteria isolated from the samples were Lactobacillus, Streptococcus, and Enterococcus species. Yeasts and molds were also detected in some of the samples, albeit in lower numbers compared to bacteria. Further analysis showed that the levels of microbial contamination varied among different brands and types of yoghurt. Factors such as production practices, storage conditions, and transportation methods may influence the extent of contamination in yoghurt products. It was noted that improper handling and storage of yoghurt could contribute to an increase in microbial contamination. Moreover, the study identified that certain microbial contaminants in yoghurt could pose health risks to consumers, especially those with weakened immune systems. Contaminants such as pathogenic bacteria and molds have the potential to cause foodborne illnesses and allergic reactions in susceptible individuals. Therefore, ensuring the microbial safety of yoghurt products is crucial for protecting public health. Recommendations were made to improve the microbial quality of yoghurt, including implementing strict quality control measures during production, storage, and distribution. Regular monitoring and testing of yoghurt samples for microbial contaminants were also suggested to prevent potential health hazards associated with consumption. In conclusion, this research highlights the importance of addressing microbial contamination in yoghurt to safeguard consumer health. By understanding the sources and types of contaminants in yoghurt products, appropriate measures can be taken to minimize the risks associated with microbial contamination. Continued research and surveillance are essential to ensure the safety and quality of yoghurt available in the market.

Project Overview

1.0   INTRODUCTION

Yoghurt is a fermented dairy product obtained from the lactic acid fermentation of milk. It is one of the most popular fermented milk products in the world and produced commercially at home. (Willey et al., 2008). In its commercial production, non fat or low fat milk is pasteurized cooled to 43°c and are inoculated with known cultures of microorganisms referred to as starter cultures. The starter cultures may be a pure culture of a particular species of Lactobacillus or a mixed culture of Streptococcus thermophilus andLactobacillus bulgaricus in a 1: 1 ratio. The coccus which is theStreptococcus thermophilus grows faster than the Rod which is theLactobacillus bulgaricus and is primarily responsible for acid production while the rod adds flavor and aroma. The growth of these Microorganisms causes the transformation of milk’s sugar, lactose into lactic acid. This process gives yoghurt it’s texture. The associative growth of the two organisms results in acid production at a rate greater than that produced by them individually.

Yoghurt is generally made from a standardized mixture containing whole milk, partially defatted milk, condensed skim milk cream and non fat dry milk. Alternatively milk may be partly concentrated by removal of 15- 20% water in a vacuum pan or by heating. While the microorganisms fermenting milk confers on it certain health benefits inadequate pasteurized milk may contain microorganism of special importance to man. (Boor and Murphy, 2002). In which its presence or absence in milk may reflect success or failure of good manufacturing practice (GMP) or cause infection when consumed together with food. This is of economic significance in Africa where the HIV/AIDS and cancer scourge has left the public who consume milk products immune suppressed and prone to bacterial and fungi infection. (Boor,2001).

Health complications associated with consumption of inadequately pasteurized milk products include serious infections that are hard, to treat with antibiotics. This becomes clinically significant if organisms isolated from an assessed sample is resistant to conventional antibiotics. Thus, can confer antibiotic resistance to the infected host while providing no alternative drug (Gould, 1994). Heat treated yoghurt do not contain lactic acid bacteria as these are killed during post fermentation. Yoghurt manufacturing companies mainly market “heat treat” yoghurt to prolong it’s shelf life (Hove et al, 1999). It is important however to evaluate the microbial gravity of some milk products sold in Nigeria. This project work aims at assessing the antimicrobial susceptibility pattern of microorganisms present in yoghurt sold in Enugu.