[1] Mathis D., Schwander F., Kopf-Bolanz K., Egger C., Portmann R.,
Absolute Quantification of 20 Major Proteins in Dairy Products by LC-MS/MS, 2013 [2] Bisig W., Collomb M., Bütikofer U., Sieber R.; Bregy M. und Etter L. (2008).
Saisonale Fettsäurezusammensetzung von Schweizer Bergmilch. Agrarforschung 15(1), 38-43.
[3] Collomb M., Bisig W., Bütikofer U., Sieber R., Bregy M., Etter L. (2008).
Fatty Acid composition of mountain milk from Switzerland. Comparison of organic and integrated farming systems. International Dairy Journal 18, 976-982.
[4] Wyss U., Mauer J., Frey H., Reinhard T., Bernet A. (2011).
Systemvergleich Milchproduktion Hohenrain. Aspekte zur Milchqualität und Saisonalität der Milchlieferungen. Agrarforschung Schweiz 2 (9): 412–417.
0.0 0.5 1.0 1.5 2.0
Nov 11
Feb 12
Apr 12
May 12
June 12
July 12
Aug 12
Sept 12
Okt 12
Nov 12
g / 100g fat
CLA C18:2
Pasture
Conventional TMR CH
TMR G
Fatty Acids and Protein Composition of milk produced under different feeding regime-“We eat what we feed”
C. Bär*, D. Mathis, M. Sutter, M. Spahni, R. Gauch, W. Bisig, L. Egger, R. Portmann
Agroscope, CH-3003 Bern, www.agroscope.ch
ALP | 2013 * Presenting and corresponding author: cornelia.baer@agroscope.admin.ch
Introduction
Results
Milk production nowadays is based on a variety of different philosophies. Currently, a consumer can only distinguish between conventional and organic milk. All other differences in the production are not transparent and the impact of the feeding regime on the composition of the milk are mainly unknown. Therefore, milk, which was produced under different feeding conditions has been analyzed for their fatty acid and protein profile.
Outlook
Methods
In order to define the fatty acid and protein composition, the milk samples were characterized by various analytical methods. Total nitrogen and fat were analyzed by using the methods of Kjeldahl and Roese- Gottlieb. Specific fatty acids were characterized by high-resolution GC-MS. The twenty most abundant milk proteins were quantified by selected reaction monitoring mass spectrometry [1] (Fig. 1).
CLA
Conjugated linoleic acid (CLA) C18:2- anti-cancer properties, additional effects on body fat reduction*
0.059 0.419 0.016 0.002 0.683 0.000 0.001 0.001 0.000 0.018 Pasture - Conv 0.007 0.832 0.007 0.000 0.047 0.000 0.000 0.000 0.000 0.024 Pasture - TMR G 0.006 0.712 0.007 0.000 0.048 0.000 0.000 0.000 0.000 0.036 Pasture - TMR CH
p-value
* D.L. Amarù et al., 2009; L.D. Whingham et al. , 2007 0.5
1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5
Nov 11
Feb 12
Apr 12
May 12
June 12
July 12
Aug 12
Sep 12
Okt 12
Nov 12
g / 100g fat
C18:1 t11
Pasture Convention al
TMR CH
Branched chain fatty acids
Trans-vaccenic acid, C18:1 t11 - Cancer inhibition, lowering of HDL cholesterol*
p-value
* Chillard et al., 2006
0.101 0.095 0.021 0.003 0.422 0.000 0.001 0.001 0.000 0.049 Pasture - Conv 0.010 0.173 0.011 0.001 0.039 0.000 0.000 0.000 0.000 0.105 Pasture - TMR G 0.008 0.181 0.008 0.002 0.030 0.000 0.000 0.000 0.000 0.176 Pasture - TMR CH
p-value
* P. M. Kris-Etherton et al., 2002; W.E. Connor et al., 2002; M. Lukas et al., 2002 0.000 0.006 0.000 0.000 0.464 0.001 0.002 0.004 0.000 0.005 Pasture - Conv 0.000 0.002 0.000 0.000 0.009 0.000 0.000 0.000 0.000 0.000 Pasture - TMR G 0.000 0.002 0.000 0.000 0.007 0.000 0.000 0.000 0.000 0.000 Pasture - TMR CH
Omega3
α-linolenic acid, C18:3 c9c12c15 – lower risk of cardiovascular diseases, positive effect on depression and stress*
0.3 0.5 0.7 0.9 1.1 1.3
Nov 11
Feb 12
Apr 12
May 12
June 12
July 12
Aug 12
Sept 12
Okt 12
Nov 12
g / 100g fat
C18:3 c9c12c15
Pasture
Conventional TMR CH
TMR G
Analysis of specific Fatty Acids shows a significant physiological advantage of pasture milk
0.000 0.001 0.002 0.003 0.004 0.005 0.006 0.007
Nov 11 Feb 12 Apr 12 May 12 June 12 July 12
g / TN / L
PERL
Pasture
Conventional TMR CH
TMR G
0.001 0.006 0.011 0.016 0.021
Nov 11 Feb 12 Apr 12 May 12 June 12 July 12
g / TN / L
TRFL
Pasture
Conventional TMR CH
TMR G
Analysis of specific proteins shows minor differences between pasture milk and other milk samples
Fig. 1: Quantification of proteins by selected reaction monitoring using isotopically labeled peptides as internal standards [1].
time Isotopically
labeled peptides
Milk Precipitated
proteins
Native peptides
**
MS/MS of the native peptide Light peptide MS/MS of the labeled peptide Heavy peptide m/z
m/z
*
* *
Analysis by LC-MS/MS
1° Selection of one
specific peptide mass 2° Collision induced dissociation (reaction)
m/z MS
MS/MS
time
intensity
m/z
Quantification by Selected Reaction Monitoring
3° Monitoring of the peptide fragments and integration
Earlier studies on the fatty acid composition showed an increase in Omega 3, CLA, branched chain fatty acids and a decrease in LDL-raising saturated fatty acids in
milk that was produced by pasture feeding [2][3][4]. Those results could be confirmed in this study.
However, the impact of the feeding on the protein composition could not be demonstrated so far, due to a lack of specific quantification methods for the different milk proteins. Milk contains a few quantitatively dominant proteins and over 100 different minor proteins. They can be regrouped into caseins, whey proteins, and proteins associated with the milk fat globule membrane (MFGM). So far, a method for the absolute quantification of individual proteins with a high concentration range was lacking. Consequently, a mass spectrometry-based method (selected reaction monitoring) was developed, which allows the simultaneous quantification of twenty major dairy proteins in different milk varieties [1] (Fig.1).
0.0004 0.0006 0.0008 0.0010 0.0012 0.0014 0.0016 0.0018
Nov 11 Feb 12 Apr 12 May 12 June 12 July 12
g / TN / L
GP2
Pasture
Conventional TMR CH
TMR G
* W.M.A. Mullan et al., 2003; S.366, “Chemie und Physik der Milch”, A. Töpel, ISBN 3-89947-131-8
Whey protein PERL
Lactoperoxidase (PERL)- part of the innate
immune system,
functions as a natural antibacterial agent*
Whey protein TRFL
Lactoferrin, (TRFL)- antibacterial, antiviral, antiparasitic, anticancer, anti-allergic and radio- protecting properties*
*reviewed in L. Adlerova et al., 2008; L. Sánchez et al., 1992
MFGM-associated protein GP2
Glycoprotein 2 (GP2)- Inhibition of Helico- bacter pylori haem- agglutination*
*reviewed in Hirmo et al., 1998
Confirm the advantage of pasture milk by quantification of fatty acids, twenty major proteins and metabolites in milk, produced under distinct feeding regimes over a period of one year.
Agroscope| Max Rubner Conference 2013 „Health Aspects of Milk and Dairy Products“
