Effects of dietary n-3 PUFA and antioxidants on beef fatty acids and lipoperoxidation in meat-producing cattle - PowerPoint PPT Presentation

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Effects of dietary n-3 PUFA and antioxidants on beef fatty acids and lipoperoxidation in meat-producing cattle

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Effects of dietary n-3 PUFA and antioxidants on beef fatty acids and lipoperoxidation in meat-producing cattle 1Dominique Bauchart*, 1Myl ne Gobert, 1,2Mihaela ... – PowerPoint PPT presentation

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Title: Effects of dietary n-3 PUFA and antioxidants on beef fatty acids and lipoperoxidation in meat-producing cattle


1
Effects of dietary n-3 PUFA and antioxidants on
beef fatty acids and lipoperoxidation in
meat-producing cattle
1Dominique Bauchart, 1Mylène Gobert, 1,2Mihaela
Habeanu, 3Parafita Emilie, 1Dominique Gruffat,
1Denys Durand
1INRA-URH, Research Centre of Clermont Fd/Theix,
France, 2Institute for Animal Biology and
Nutrition, Balotesti, Romania, 3Association for
the development of meat industry (ADIV),
Clermont- Ferrand France.
2
Introduction
Consumers are now aware of the putative link
between meat lipid consumption and human health.
An increased intake of n-3 (?3) PUFA (from animal
products) together with a low ratio of PUFA
n-6/n-3 (close to 5) would be beneficial for
human health. Since feeding of cattle with
linseed-supplemented diets increased n-3 PUFA of
lipids in both fresh and cooked meats, beef can
be a potential source of n-3 PUFA for humans.
However, in this context, this strategy could
modify beef minor FA (CLA, trans 181) having
various effects on human health. Moreover, beef
lipoperoxidation can be stimulated not only by
the high sensibility of n-3 PUFA to reactive
oxygen species attacks during oxidative stress,
but also by a non adequate status in dietary or
endogenous antioxidants. Moreover, beef
lipoperoxidation is potentially stimulated i) by
a pre-slaughter stress of animals , ii) by
technological processes applied to beef.
3
Objectives
Linseed and rapeseed
Normand cull cows
Beef enriched with n-3 PUFA
  • Here are presented some main results of the
    "Lipivimus" Research Program financed by the
    French National Research Agency (ANR, 2007-2009)
    concerning the impact of two dietary lipid
    sources of n-3 PUFA (linseed, linseed rapeseed)
    provided with or without antioxidants (vitamin E,
    plant extracts rich in polyphenols, PERP) in
    finishing cull cows on
  • beef FA characteristics related to their health
    value for consumers,
  • beef lipoperoxidation at slaughter or following
    technological treatments in normal or
    stressed animals just prior slaughtering.

4
  • Effects of dietary n-3 PUFA and antioxidants
  • on beef fatty acids

5
Effects of n-3 PUFA and antioxidants on beef
fatty acidsExperimental aspects (I)
  • Animals and diets

72 finishing cull Normand cows
6
Effects of n-3 PUFA and antioxidants on beef
fatty acidsExperimental aspects (II)
  • Beef collection and treatments

Cows slaughtered at a mean LW of 787kg for the
three diets ( body fat score 3.5 BW gain
1.52kg/d) for the 100d-finishing period.
150 g of Longissimus thoracis muscle ?
collected 1d post mortem, ? cut into pieces
and freezed in liquid N2 ? ground in liquid N2
to produce a representative and fine
powder Beef powder stored at -20C
until analysis.
7
Effects of n-3 PUFA and antioxidants on beef
fatty acidsAnalytical aspects
Beef fatty acid preparation and
analysis Extraction of total beef lipids by
mixing beef powder with chloroform/methanol
(Folch et al.,1957). Extraction and methylation
of fatty acids (FA) by transmethylation
with Na2 methanolate followed with
BF3-methanol Total FA composition
determination by gas-liquid chromatography in
a CP Sil 88 glass capillary column (100m long
x 0.25mm ID, Varian H2 as the carrier gas).
Trans 181 analysis - purification of total
trans 181 by preparative HPLC- UV
detection identification/ distribution of trans
181 isomers by GLC- mass spectrometry
8
Chemical composition of experimental diets
9
Effects of linseed and rapeseed on beef fatty
acids (Habeanu et al, 2009)
Diets Control Linseed Linseed rapeseed P
Saturated FA ( AG) 47.0 48.2 48.3 0.440
Cis MUFA ( AG) 45.4a 41.6b 40.9b lt0.0001
Trans MUFA ( AG) 2.46a 4.08b 5.04c lt0.0001
183n-3 ( AG) 0.39a 0.61b 0.53ab 0.050
CLA ( AG) 0.32 0.48 0.45 0.080
PUFA n-6/ PUFA n-3 4.54a 3.32b 4.10ab 0.028
Total FA (g/100g LT muscle ) 3.95 3.64 3.63 0.640
10
Effects of lipid and antioxidant supplements on
beef fatty acids
  • Linseed or linseed rapeseed supplements did
    not increase beef lipids.
  • Higher of 183 n-3 and 9c,11tr 182 (CLA)
    and a lower ratio PUFA n-6/ PUFA n-3 of beef FA
    with linseed (and linseed rapeseed at a lower
    extent) supplement were favorable for the human
    health,
  • Addition of antioxidants (vitamin E and PERP)
    reinforced the beneficial effect of lipid
    supplements, suggesting a modulation of the
    microbial FA metabolism by the dietary
    antioxidants in the rumen.
  • The large increase in trans MUFA, dominated by
    trans 181, led to the question of their
    nutritional value. Indeed, 181?11tr (vaccenic
    acid) generally abundant in beef would protect
    against cardiovascular disease (CVD) whereas
    181?9tr (elaidic acid) and 181?10tr would be
    rather detrimental by favouring atherosclerosis,
    CVD inflammation and diabetes.

11
Effects of lipid supplements on beef trans 181
isomers
Analytical aspects
  • Purification of total trans 181 from beef FAME
  • By preparative reversed-phase HPLC
  • Use of a series of two Kromasil KR100-5C18
    inverse phase columns (5µm, 250mm x 10mm) with
    acetonitrile (eluting solvent, 4mL/min)
    detection at 206 nm.
  • Separation of trans 181 isomers
  • Structural characterization and quantification
    of each individual trans 181 isomer by GLC
    Mass Spectrometry
  • Convertion of methyl trans 181 into dimethyl
    disulfide (DMDS) adducts

12
GLC separation of beef trans 181 isomers
13
Compared effects of linseed vs rapeseed linseed
on beef trans 181 isomers ( total trans
181)(Bauchart et al, 2009)
14
Compared effects of linseed vs rapeseed linseed
on beef trans 181 isomers
  • Direct impact of dietary lipid sources on trans
    181 isomers on the health value of beef when
    dietary FA were dominated by 183 n-3 (linseed)
    or by 181 n-9 associated with lower amounts of
    182n-6 and 183n-3 (linseed rapeseed),
  • Higher health value of beef trans 181 with the
    addition of linseed (reduction of ?9tr and ?10tr
    pro-atherogenics),
  • But, negative effect of linseed and rapeseed on
    the health value of beef trans 181 (reduction of
    ?11tr anti atherogenic).

15
Breeding and technological factors and beef
lipoperoxidation
16
Beef lipoperoxidation methodological aspects
  • Methods for lipoperoxidation characterization
  • Malondialdehyde (MDA) production measured by HPLC
    (fluorescence detection) or hydroxyalkenals (HHE
    and HNE) by GC- MS,
  • In vitro susceptibility of plasma/tissue(homogenat
    e) to lipoperoxidation evaluated by measuring the
    kinetic production of conjugated dienes (CD)
    indicating i) the degree of resistance to
    lipoperoxidation (Lag phase), ii) the
    lipoperoxidation velocity (Tx max) iii) the
    maximal amount of produced CD (Q max).
  • Technological treatments of beef
  • Collected just after slaughter, stored under
    vacuum or in carcass for 12 d at 4C and
    finally cut in steaks as on the classic market,
  • Packaged at 4C in a tray overwrapped with a
    film
  • i) under air for 4 d. (A), ii) under modified
    atmosphere (7030, O2/CO2) for 7 d. (MA), or in a
    bag iii) under vacuum for 14 d. (V),
  • ? Ground into a powder in liquid N2 and stored at
    -80C.

17
Effets of maturation and packaging treatments on
beef lipoperoxidation
(Gobert et al, 2008 and 2009)
17 / 15
18
Packaging treatments and beef peroxidation and
colour Effect of linseed and antioxidants given
to cows in the finishing period (Gobert et al ,
2009, Parafita et al, 2008)
19
Packaging treatments and beef peroxidation Effect
of linseed and antioxidants and of emotional
stress just prior slaughter (Durand et al ,
2009)
20
Breeding and technological factors and beef
lipoperoxidation
  • Beef lipoperoxidation
  • Increased with the contact of meat with O2 during
    packaging
  • ? stimulated in beef from cows given
    linseed-supplemented diet
  • Prevention of beef against lipoperoxidation most
    effective from animals given dietary vit E
  • PERP than with vit E alone
  • ? especially in beef packaged with O2
  • Emotional and physical stress of animals highly
    increased beef lipoperoxidation, especially in
    beef packaged with O2 from cows given
    linseed-supplemented diet
  • Beef colour
  • Beef colour inversely varied with
    lipoperoxidation
  • Oxidation of beef myoglobin (into metmyoglobin)
    generally increased with beef packaging
  • Partial prevention of myoglobin oxidation only
    with beef from animals given vit E PERP
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