Contents - Faperta

16
Detection and Monitoring of Food and Food
Products Derived from Genetically Modifi ed Crops
Introduction
The global area under genetically modifi ed crops has increased from 1.7 million hectares
in 1996 to over 100 million hectares in 2006, and nearly one-third of the area under transgenic
crops was in developing countries ( James, 2007). The major transgenic crops include
soybean (60%), corn (23%), cotton (12%), canola (5%), and potato (~1%). The major traits
include herbicide tolerance (71%), insect resistance (28%), and quality traits (1%). More than
8 million farmers have benefi ted from this technology, and 90% of the benefi ciaries are the
resource-poor farmers in developing countries. Although considerable progress has been
achieved in the development of analytical methods for detection of genetically modifi ed
food based on polymerase chain reaction (PCR), several other analytical technologies,
including mass spectrometry, chromatography, near infrared spectroscopy, micro fabricated
devices, and DNA chip technology (microarrays), can also be used for monitoring and
detection of genetically modifi ed food. So far, only PCR-based methods have been accepted
for regulatory purposes. Monitoring and detection of genetically modifi ed crops consists
of three distinct steps, detection, identifi cation, and quantifi cation.
Detection: To determine whether a product has genetically modifi ed plant material
or not, a general screening method can be used, which could be positive or negative.
The screening methods are usually based on the PCR, immunoassays, or bioassays.
Analytical methods for detection must be sensitive and reliable enough to
obtain accurate and precise results.
Identifi cation: To fi nd out which genetically modifi ed crops or transgenes are present
in food, and whether they are authorized or not in a particular country. DNAbased
methods or immuno assays can be used for this purpose.