AOACSPIFANMethods-2017Awards

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210 Golay & Moulin: Journal of AOAC International Vol. 99, N o. 1, 2016
INFANT FORMULA AND ADULT NUTRITIONALS
A collaborative study was conducted on AOAC First
Action Method 2012.13 “Determination of Labeled
Fatty Acids Content in Milk Products and Infant
Formula by Capillary Gas Chromatography,” which
is based on an initial International Organization for
Standardization (ISO)–International Dairy Federation
(IDF) New Work Item that has been moved forward
to ISO 16958:2015 | IDF 231:2015 in November 2015.
It was decided to merge the two activities after
the agreement signed between ISO and AOAC in
June 2012 to develop common standards and to
avoid duplicate work. The collaborative study was
performed after having provided highly satisfactory
single-laboratory validation results [Golay, P.A., &
Dong, Y. (2015) J. AOAC Int. 98, 1679–1696] that
exceeded the performance criteria defined in AOAC
Standard Method Performance Requirement (SMPR®)
2012.011 (September 29, 2012) on 12 products
selected by the AOAC Stakeholder Panel on Infant
Formula (SPIFAN). After a qualification period of
1 month, 18 laboratories participated in the fatty
acids analysis of 12 different samples in duplicate.
Six samples were selected to meet AOAC SPIFAN
requirements (i.e., infant formula and adult nutritionals
in powder and liquid formats), and the other Six
samples were selected to meet ISO-IDF requirements
(i.e., dairy products such as milk powder, liquid milk,
cream, butter, infant formula with milk, and cheese).
The fatty acids were analyzed directly in all samples
without preliminary fat extraction, except in one
sample (cheese). Powdered samples were analyzed
after dissolution (i.e., reconstitution) in water, whereas
liquid samples (or extracted fat) were analyzed
directly. After addition of the internal standards
solution [C11:0 fatty acid methyl ester (FAME) and
C13:0 triacylglycerols (TAG)] to the samples, fatty
acids attached to lipids were transformed into FAMEs
by direct transesterification using methanolic sodium
methoxide. FAMEs were separated using highly polar
capillary GLC and were identified by comparison
with the retention times of pure analytical standards.
Quantification of fatty acids was done relative to C11:0
FAME as internal standard and to instrument response
factors (determined separately using calibration
standards mixture). The performance of the method
(i.e., transesterification) was monitored in all samples
using the second internal standard, C13:0 TAG. RSDR
values were summarized separately for labeled fatty
acids in SPIFAN materials and ISO-IDF materials due
to different expression of results. This method was
applied to representative dairy, infant formula, and
adult/pediatric nutritional products and demonstrated
global acceptable reproducibility precision for all fatty
acids analyzed (i.e., 46 individuals and/or groups) for
these categories of products.
It is well known that fatty acids play an important role in human
nutrition at all periods of life. Some fatty acids are considered
more desirable than others (i.e., essential fatty acids), and
some, like the saturated fatty acids (SFAs) and the industrial trans
fatty acids (TFAs), need to be decreased and limited in foods
due to their potential contributions to cardiovascular diseases.
Fatty acids are naturally present in oils and fats used as raw
materials but in different concentrations. As a consequence, they
are also present in manufactured food products for which strict
nutritional recommendations and/or regulation are sometimes
given according to the target population.
To support the labeling of fatty acids, the food industry (as
well as governmental laboratories) needs reliable and horizontal
methods for analyzing the whole fatty acids spectrum, including
TFAs. To address this need, amethod involving direct preparation
of fatty acid methyl esters (FAMEs) using a high-resolution
Determination of Labeled Fatty Acids Content in Milk
Products, Infant Formula, and Adult/Pediatric Nutritional
Formula by Capillary Gas Chromatography: Collaborative
Study, Final Action 2012.13
Pierre-Alain G olay and J ulie Moulin
Nestlé Research Center, Vers-chez-les-Blanc, 1000 Lausanne 26, Switzerland
Collaborators: M. Alewijn; U. Braun; L.F. Choo; H. Cruijsen; P. Delmonte; J. Fontecha; S. Holroyd; G. Hostetler; F. Lacoste; C. Lehmann;
L. Nagelholt; S. Phillips; T. Ritvanen; A. Rizzo; O. Shimelis; C. Srigley; D. Sullivan and P. Trossat
Received May 29, 2015. Accepted by AK July 31, 2015.
The method was approved by the AOAC Official Methods Board
as Final Action. See “Standards News,” (2014) Inside Laboratory
Management, November/December issue.
The AOAC Stakeholder Panel on Infant Formula and Adult
Nutritionals (SPIFAN) invites method users to provide feedback on the
Final Action methods. Feedback from method users will help verify
that the methods are fit for purpose and are critical to gaining global
recognition and acceptance of the methods. Comments can be sent
directly to the corresponding author.
Appendixes are available on the J. AOAC Int. website
Corresponding author’s e-mail:
DOI: 10.5740/jaoacint.15-0140
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