File Name: bacteriology of water milk and food .zip
- Types of microorganisms and their activity in milk
- Methylene Blue Dye Reduction Test for Assessing the Raw Milk Quality
- Sources and Causes of High Bacteria Counts in Raw Milk: An Abbreviated Review
- The Evolving Role of Coliforms As Indicators of Unhygienic Processing Conditions in Dairy Foods
Metrics details. Urban water sources of Khamis Mushait Governorate, southwestern Saudi Arabia, were studied to assess their bacteriological characteristics and suitability for potable purposes. A cross-sectional epidemiological method was adopted to investigate the four main urban water sources i. These were sampled and examined between February and June
Types of microorganisms and their activity in milk
Bacterial count in prepared food or water is a key factor in assessing the quality and safety of food. It also reveals the level of hygiene adopted by food handlers in the course of preparation of such foods. This comparative study evaluated the bacteriological quality of food and water consumed in Nsukka, Enugu state, Nigeria, using three bacteria enumeration methods. Data obtained are assumed to reflect the level of personal and environmental hygiene in the study population. Ten types of foods—beans, yam, abacha, okpa, moimoi, pear, cassava foofoo , rice, agidi, and garri —and 10 water samples were evaluated for bacteriological quality, precisely determining the level of coliform contamination, using the most probable number MPN , lactose fermentation count LFC , and Escherichia coli count ECC methods.
Microorganisms are living organisms that are individually too small to see with the naked eye. Microorganisms are found everywhere ubiquitous and are essential to many of our planets life processes. With regards to the food industry, they can cause spoilage, prevent spoilage through fermentation, or can be the cause of human illness. Bacteria are relatively simple single-celled organisms. One method of classification is by shape or morphology:. There exists a bacterial system of taxonomy, or classification system, that is internationally recognized with family, genera and species divisions based on genetics.
Methylene Blue Dye Reduction Test for Assessing the Raw Milk Quality
The numbered list below identifies seven types of bacteria according to how they change the properties of milk. Often these changes are negative spoilage but as we will see in later sections, many of these bacteria are important to the development of cheese flavour. Before proceeding to the list, please note the following definitions:. Keeping the above definitions in mind, note the following types of microorganisms, grouped according to their impact on milk quality. For now note the following:. Most important in cheese milk are species of:.
Sources and Causes of High Bacteria Counts in Raw Milk: An Abbreviated Review
Testing for coliforms has a long history in the dairy industry and has helped to identify raw milk and dairy products that may have been exposed to unsanitary conditions. Coliform standards are included in a number of regulatory documents e. As a consequence, detection above a threshold of members of this method-defined, but diverse, group of bacteria can result in a wide range of regulatory outcomes. Most bacterial genera that comprise the coliform group e. The presence of coliforms has long been thought to indicate fecal contamination, however, recent discoveries regarding this diverse group of bacteria indicates that only a fraction are fecal in origin, while the majority are environmental contaminants.
The Evolving Role of Coliforms As Indicators of Unhygienic Processing Conditions in Dairy Foods
The process is intended to destroy or deactivate organisms and enzymes that contribute to spoilage or risk of disease, including vegetative bacteria , but not bacterial spores. The process was named after the French microbiologist, Louis Pasteur , whose research in the s demonstrated that thermal processing would deactivate unwanted microorganisms in wine. Today, pasteurization is used widely in the dairy industry and other food processing industries to achieve food preservation and food safety.
Beresford, R. Paul Ross, Gerald F. Fitzgerald, Paul D. Here, we review what is known about the microorganisms present in raw milk, including milk from cows, sheep, goats and humans. Milk, due to its high nutritional content, can support a rich microbiota. These microorganisms enter milk from a variety of sources and, once in milk, can play a number of roles, such as facilitating dairy fermentations e.
•Drinking water has to be visually acceptable, clear, colourless Types of bacteria in milk Staph food poisoning, Salmonellosis and Q fever.
Milk is synthesized in specialized cells of the mammary gland and is virtually sterile when secreted into the alveoli of the udder Tolle, Beyond this stage of milk production, microbial contamination can generally occur from three main sources Bramley and McKinnon, : from within the udder, from the exterior of the udder, and from the surface of milk handling and storage equipment. The health and hygiene of the cow, the environment in which the cow is housed and milked, and the procedures used in cleaning and sanitizing the milking and storage equipment are all key in influencing the level of microbial contamination of raw milk. Equally important are the temperature and length of time of storage, which allow microbial contaminants to multiply and increase in numbers. All these factors will influence the total bacteria count or Standard Plate Count SPC and the types of bacteria present in bulk raw milk. Please check this link first if you are interested in organic or specialty dairy production. Raw milk as it leaves the udder of healthy cows normally contains very low numbers of microorganisms and generally will contain less than 1, total bacteria per ml Kurweil,
Bacteriological water analysis is a method of analysing water to estimate the numbers of bacteria present and, if needed, to find out what sort of bacteria they are.
The articles in this key work, heavily illustrated and fully revised since the first edition in , highlight advances in areas such as genomics and food safety to bring users up-to-date on microorganisms in foods. Topics such as DNA sequencing and E. With lists of further reading to help users explore topics in depth, this resource will enrich scientists at every level in academia and industry, providing fundamental information as well as explaining state-of-the-art scientific discoveries.
Methylene Blue Dye Reduction Test, commonly known as MBRT test is used as a quick method to assess the microbiological quality of raw and pasteurized milk. This test is based on the fact that the blue colour of the dye solution added to the milk get decolourized when the oxygen present in the milk get exhausted due to microbial activity. The sooner the decolourization, more inferior is the bacteriological quality of milk assumed to be.
The dairy products industry is going toward safe milk and its products in the food market. The aim of this work is focused on milk microbial contamination and its impacts on milk production and dairy industry with their implications in milk product quality, food-borne diseases from raw milk, and unpasteurized milk by food-borne pathogen microbial contamination and milk and dairy product spoilage. The microbial milk contamination source comes from herd hygiene and health status, mastitis prevalence, production environment, and milking parlor and milk conserving practices in dairy farm. Moreover, these facts are implicated in milk quality and milk spoilage and unsafe dairy products.
Bacteria are the most important microorganisms to the food processor. Most are harmless, many are highly beneficial, some indicate the probable presence of filth, disease organisms, spoilage and a few cause disease.
Faecal pollution of water supplies may lead to introduction of a variety of intestinal pathogens that comprise water-borne diseases Table While evaluating faecal pollution of water supplies, one has to keep in view the bacterial flora in water Table The coliforms ferment lactose, e.