Dear All
If we look at AOAC Official Method 963.22 which is most commonly follwed method -two things are very clear.
one - in the process of methyl ester formation free fatty acids as well as fatty acids in tri acyl glycerol or in membrane lipids are all esterified.
two- sum area under different fatty acids peaks in chromatogram is taken 100 so fatty acid amount in a particular food sample is a per cent proprtion of total fatty acids. Hence, results are in percent fatty acids and not affected by methyl or butyl esterification.
Dr. Rakesh Bhardwaj
Senior Scientist (Biochemistry)
Germplasm Evaluation Division
National Bureau of Plant Genetic Resources (NBPGR)
PUSA Campus, New Delhi - 110 012
India
Phone (+91)11-25848074(O),(+91)11-25842495(Fax)
(+91)9560487889 (M), (+91) 9015405449
--- On Thu, 4/4/13, Elizabeth Lund <[log in to unmask]> wrote:
From: Elizabeth Lund <[log in to unmask]>
Subject: Re: non-esterified fatty acid concentration
To: [log in to unmask]
Date: Thursday, April 4, 2013, 5:34 AM
Dear All,
When analysing fatty acid composition of foods it is normal to hydrolyse the fatty acids from the glycerol as occurs in the gut. I do not see the relevance of free fatty acids per se in food. In people it is a different matter.
Elizabeth Lund
Independent Consultant
Nutrition and Gastrointestinal Health
Tel. +441508488049
Mob. +447841529097
http://www.elizabethlund.co.uk
From: Anders Møller <[log in to unmask]>
Organization: Danish Food Information
Reply-To: <[log in to unmask]>
Date: Thursday, 4 April 2013 08:29
To: <[log in to unmask]>
Subject: Re: non-esterified fatty acid concentration
Dear David,
Isn’t that the information we carry in almost all food composition databases/tables?
We recalculate the analysed methyl (or butyl) ester concentrations of fatty acids to express the data as “free” or non-esterified fatty acids?
If not, could you then elaborate a little on what is then meant?
All the best,
Anders
Anders Møller
Danish Food Information
Borgediget 12
DK-4000 Roskilde, Denmark
Websites: Danish Food Information (http://www.danfood.info)
SciName Finder™ (http://www.sciname.info)
LanguaL™ (http://www.langual.org)
From: Food Composition Discussion Group [mailto:[log in to unmask]] On Behalf Of Haytowitz, David
Sent: 03 April 2013 23:36
To: [log in to unmask]
Subject: non-esterified fatty acid concentration
Hello:
We got a request asking if we had anything on the non-esterified fatty acid concentration of foods. Also, if anyone is working in this area.
Thank you,
David
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