While yogurt is generally viewed as a
health food there are specific dangers for the consumers and the manufacturers.
The most important of these is the presence of harmful microorganisms. The main
investigative procedures to determine the health of yogurt is testing
for yeast, mold and the presence of coliform. Traditional testing methods
tend to be slow and labor intensive. This makes them unsuitable for products
with a relatively short life such as yogurt. This has led to an interest in
more rapid methods of determine the safety of yogurt before it is delivered to store
shelves.
An
Overview of Yogurt
Yogurt is one of the oldest dairy
products in the world. Food historians believe that people have been consuming
yogurt for more than 5,400 years. Yogurt has also proved to be a very popular
food with health conscious consumers. One recent study published in Nutrition
Research which looked at 6,500 men and women, showed that people who consumed
two or more servings of yogurt a week had a healthier edit overall compared to
the general population.
In simple terms, yogurt is a form of
curdled milk. The bacteria contained in the milk ferments and coagulates. This
causes the milk to thicken which creates yogurts signature creamy texture and
slightly tangy, astringent taste. Added to the yogurt are flavoring and colors
to give yogurts a unique appearance and taste. There are a variety of different
yogurt types currently on the market. In general plain yogurt is made from cow
milk and does not contain any additional flavoring or sweeteners. Flavored
yogurts have fruit and other flavorings added. Generally these flavored yogurts
will also have sugar added in order to change the astringent flavor of yogurt.
The sugar also helps to preserve the fruit.
Coliform
Assay
Coliform
bacteria are a very common indicator use to assess the sanitary quality of
both foods and water. A coliform is a rod-shaped non spore forming bacteria
which is able to ferment in lactose if incubated at between 35 to 37 degrees.
Coliforms are found many different types of environment including water, soil,
vegetation and inside of the intestinal tracks of warm blood animals.
Most coliforms do not cause any disease
however there is a danger of illness in vulnerable groups of people including
children. Coliforms typically enter the milk used in yogurt due to poor milking
practices or incorrectly washed equipment. This occurs because the bacteria are
contained inside the feces of cows.
The coliform count contained in
dairy products is a good indication of the sanitation involved in the
processing and handling of the diary product. Pasteurization always eliminates
coliform and so if pasteurization has occurred then we can assume that
contamination has occurred after this point, usually during packaging or manufacturing.
The traditional method to check
for the presence of coliform bacteria is the agar plate method. However
more recently rapid detection methods such as the automated assay methods have
been developed. These methods
yield faster test times with a greater degree of accuracy compared to plate
methods.
Yeast
and Mold Testing
Another common test performed to
indicate the hygiene of yogurt is for yeast and mold. The traditional
method to assess yogurts and mold is the colony count method. In general
this method takes between 5 – 7 days in order to determine the results. Studies
have shown that more recently developed rapid detection methods can reduce this
time-scale by more than 50%.
Interpreting traditional colony count
result can be difficult. Newer methods minimize the possibility of mistakes
made due to human error. This also enables skilled technicians to concentrate
on more important tasks. Overall rapid detection methods for yeast and mold
save laboratories time and money while producing more accurate results.
The development of yogurt bacterial
testing methods with shorter time scales and greater accuracy are allowing to
manufacturers to deliver safer yogurt to their consumers. Health conscious
yogurt consumers are particularly aware and interested in the safety of the
food that they eat. This makes these new testing methods vital for any yogurt
manufacturer concerned with protecting their brand.
Contact Biolumix to learn more
about coliform testing and the microbiological testing of yogurt or other food
items.
Biolumix
3928 Varsity Dr.
Ann Arbor, MI 48108
Phone: (734) 984-3100
Fax: 734-222-1830
Email: info@mybiolumix.com
http://plus.google.com/103841943418192727689
