3.3 Detection
3.3.1 Chemical Contaminants
The accessibility of rapid and sensitive approaches to determine chemical contaminants in dairy products is critical in food safety control laboratories. In countries like
the USA, there is a practice to analyze individual farm milk supply for chemical
contaminants before allowing to pool with the bulk milk (Kumar et al. 2012). To
detect contaminants in milk, different methods have been developed which include
screening methods and chromatographic techniques to detect as many contaminants
as possible. The screening methods are based on the susceptibility of bacteria to
different contaminants including antibiotics (Mitchell et al. 2002). They are very
cost-effective, and in contrast to, for example, immunological or receptor-based
tests, they have the potential to cover the entire spectrum within one test. However,
these methods have their drawbacks as they do not enable specific identification that
limits their use. They are highly sensitive to specific groups of contaminants but
evidently less sensitive (Navratilova´ 2008). Quantitative confirmatory methods
such as high-performance liquid chromatography (HPLC) (Zhou et al. 2009), gas
chromatography–mass spectrometry (GC–MS) (Azzouz et al. 2010, 2011), thinlayer chromatography (TLC) (Grzelak et al. 2009), and mass spectrometry
(MS) (Blascoa et al. 2009) have been commonly used for the detection of contaminants having safety concern. However, again each method has one or more limitations in terms of precision, accuracy, sensitivity, infrastructural requirement, and
ease of method (Kumar et al. 2012).
3.3.2 Microbial Contaminants
Presently, the conventional testing methods that are considered as gold standard tests
are among the first choice of the quality control laboratory. These conventional
methods generally involve isolation and confirmation procedures for the detection of
the microbes and other platform tests that are carried to determine non-microbial
contaminants of the milk which are often time-consuming and laborious to perform.
The other associated problem with such tests is that the product needs to be hold till
the results come. This adds up to working capital of the industry because the holding
infrastructure has to be created. Moreover, the perish ability of the milk and milk
products further adds up to the problem of storage of these products. In such
circumstances the milk and milk products are often pushed into the market without
screening. The only thing the industry can do is banning the product and recalling the
product. To overcome this unmanageable situation, dairy industry is looking for
alternatives to conventional methods. The methods that are rapid, cost-effective, and
easy to perform and significantly validated with approved standard methods are the
need of the hour (Thakur et al. 2013).
100
H. V. Raghu et al.
3.3.1 Chemical Contaminants
The accessibility of rapid and sensitive approaches to determine chemical contaminants in dairy products is critical in food safety control laboratories. In countries like
the USA, there is a practice to analyze individual farm milk supply for chemical
contaminants before allowing to pool with the bulk milk (Kumar et al. 2012). To
detect contaminants in milk, different methods have been developed which include
screening methods and chromatographic techniques to detect as many contaminants
as possible. The screening methods are based on the susceptibility of bacteria to
different contaminants including antibiotics (Mitchell et al. 2002). They are very
cost-effective, and in contrast to, for example, immunological or receptor-based
tests, they have the potential to cover the entire spectrum within one test. However,
these methods have their drawbacks as they do not enable specific identification that
limits their use. They are highly sensitive to specific groups of contaminants but
evidently less sensitive (Navratilova´ 2008). Quantitative confirmatory methods
such as high-performance liquid chromatography (HPLC) (Zhou et al. 2009), gas
chromatography–mass spectrometry (GC–MS) (Azzouz et al. 2010, 2011), thinlayer chromatography (TLC) (Grzelak et al. 2009), and mass spectrometry
(MS) (Blascoa et al. 2009) have been commonly used for the detection of contaminants having safety concern. However, again each method has one or more limitations in terms of precision, accuracy, sensitivity, infrastructural requirement, and
ease of method (Kumar et al. 2012).
3.3.2 Microbial Contaminants
Presently, the conventional testing methods that are considered as gold standard tests
are among the first choice of the quality control laboratory. These conventional
methods generally involve isolation and confirmation procedures for the detection of
the microbes and other platform tests that are carried to determine non-microbial
contaminants of the milk which are often time-consuming and laborious to perform.
The other associated problem with such tests is that the product needs to be hold till
the results come. This adds up to working capital of the industry because the holding
infrastructure has to be created. Moreover, the perish ability of the milk and milk
products further adds up to the problem of storage of these products. In such
circumstances the milk and milk products are often pushed into the market without
screening. The only thing the industry can do is banning the product and recalling the
product. To overcome this unmanageable situation, dairy industry is looking for
alternatives to conventional methods. The methods that are rapid, cost-effective, and
easy to perform and significantly validated with approved standard methods are the
need of the hour (Thakur et al. 2013).
100
H. V. Raghu et al.