Download Symposium on analytical method challenges for measuring nutrients

Symposium on analytical method challenges for measuring nutrients
and antinutrients in plants: Introduction to the symposium1
W. D. Price2
Office of Surveillance and Compliance, Center for Veterinary Medicine,
Food and Drug Administration, Rockville, MD 20855
The Food and Agriculture Organization (FAO) of the
United Nations and the World Health Organization
(WHO) collaborated in 1990 to provide guidance for
safety assessment of bioengineered plants. It established that the comparison of the final product to an
appropriate comparator having an acceptable standard
of safety is an important element in the safety assessment (WHO, 1991).
The Organization for Economic Cooperation and Development (OECD) in 1993 devised a concept of substantial equivalence as the best strategy for the outcome of the comparative approach for the safety and
nutritional assessment of genetically modified foods
(OECD, 1993). Substantial equivalence is considered a
key step in the safety assessment process, but by itself,
is not the entire safety assessment. The FAO/WHO
Expert Consultation on Biotechnology and Food Safety
(FAO/WHO, 1996) concluded that a compositional comparison of the bioengineered food to its non-modified
comparator is a very important step in determining
substantial equivalence. It further concluded that the
data for the comparator can be the ranges reported in
the published literature as well as data from direct
comparisons with the GM variety. The Expert Consultation also felt that the comparison should be made on
the critical components of the food (i.e., key nutrients,
key toxicants and key antinutrients for the food source
in question).
In 2000, a Joint FAO/WHO Expert Consultation on
Foods Derived from Biotechnology concluded that the
concept of substantial equivalence is a practical approach to the safety assessment of genetically modified
food (FAO/WHO, 2000). It agreed with the other groups
that substantial equivalence is the first step in safety
assessment process, although it does not necessarily
1
Symposium sponsors: Center for Veterinary Medicine, U.S. Food
and Drug Administration and the Canadian Food Inspection Agency.
2
Correspondence: HFV-200, 7500 Standish Place (phone: 301-8276652; fax: 301-594-1812; E-mail: [email protected]).
Received November 12, 2002.
Accepted May 6, 2003.
characterize all the hazards. The Expert Consultation
concluded that the use of the substantial equivalence
approach contributes to a robust safety assessment
framework.
The OECD in 1997 moved to focus its work on the
development of science-based consensus documents
(OECD, 1997). The primary emphasis was to be on the
composition of important food plants that had been or
were being modified, and would be used for human food
or animal feed. The documents outline the origin of the
food/feed crop, its world-wide use, its processing for
food/feed, the nutrients for which it is included in the
diet, the toxicants and antinutrients present and the
significance of their presence. Each document suggests
key nutrients, key toxicants and key antinutrients to
be analyzed and compared for substantial equivalence
for both food and feed. Various countries have taken
the lead in authoring consensus documents: Canada
(canola), United States (soybean), Germany (potato and
sugar beet), United States and The Netherlands
(maize), and Australia (wheat). Other documents are in
preparation: rice (Japan, Canada, and United States),
cotton (United States), sunflower (France), barley (Germany, Finland, and United States) and forages (U.K.).
Measuring the composition of plants as recorded in
the OECD documents is inherent to animal nutrition.
When one looks at the literature for reports on plant
composition, it is apparent that analytical methods influence the values reported. Some of these methods pose
significant challenges. It is evident that it makes no
difference whether one is evaluating bioengineered or
nonbioengineered plants, the challenges are the same.
This symposium was designed to address, through the
eyes of nutritionists and chemists, some of the analytical method challenges for the composition of all plants.
It seemed natural to separate the topics into minerals, nonfiber carbohydrates (NFC), insoluble dietary fiber (IDF), fat, antinutrients/toxicants, and moisture.
The first paper addresses minerals in feedstuffs and
some of the challenges associated with those methods,
such as complications in freeing the minerals from the
plant matrix in the right oxidation state and free of
interfering material. Another important discussion
topic is instrumentation. Papers two and three address
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Analytical methods symposium motivation
plant fiber methods. The multiple challenges in selecting a relevant analytical system that is applicable to
food and feed NFC are confronted in the second paper.
The third paper addresses IDF methods with a goal to
discuss challenges in accurately evaluating the nutritional quality of fiber in the diet. The fourth paper
explores the problems with current fat methods and
the lack of applicability of the results to nutrition. The
author suggests a preferred method of fat analysis. The
fifth paper reviews the current status of method for
measuring the antinutrient/toxicants raffinose, oligosaccharides, pentosan, phytic acid, and glucosinolates.
Recommendations for best analytical practice are suggested. The sixth and last paper addresses challenges
in measuring moisture content of feed. The attributes
and challenges with several methods are discussed.
Literature Cited
FAO/WHO. 1996. Report of the Joint FAO/WHO Expert Consultation
on biotechnology and food safety: review of existing safety evaluation strategies and guidelines. Food and Agriculture Organization of the United Nations and the World Health Organization,
Rome, Italy. Available: http://www.fao.org/es/esn/biotech.htm.
FAO/WHO. 2000. Report of the Joint FAO/WHO Expert Consultation
on foods derived from biotechnology, held in Geneva, Switzerland. Food and Agriculture Organization of the United Nations
and the World Health Organization, Rome, Italy. Available:
http://www.fao.org/es/esn/biotech.htm.
OECD. 1993. Safety evaluation of foods produced by modern biotechnology: Concepts and principles. Organization for Economic Cooperation and Development, Paris, France.
OECD. 1997. Toxicological and nutritional testing of novel foods.
Report of the OECD Workshop, Aussois, France. Organization
for Economic Cooperation and Development, Paris, France.
WHO. 1991. Strategies for assessing the safety of foods produced by
biotechnology. Report of a Joint FAO/WHO Consultation. World
Health Organization, Geneva, Switzerland.