Transcript Producer talk - Lacombe Meat Lipid Network

AAFC-Lacombe
Why conduct beef fat research?
• A 1200 lb steer with ½ inch backfat, average muscling,
yields a 750 pound carcass.
• The 750 pound carcass yields approximately:
– 490 pounds boneless trimmed beef
– 150 pounds fat trim
– 110 pounds bone
• Marbling fat is highly prized and is used to
determine carcass value (grades A, AA, AAA,
Choice).
• The value of trim fats is much lower than
marbling and considered mostly a low vlaue
waste.
• Our beef fat research tries to change fat
content and composition to add carcass
value.
• Beef fat has been scorned by health
officials due to saturated fatty acid
(SFA) content, and its association with
cardiovascular, diabetes and other
diseases.
• We’re interested in investigating ways to
improve the healthfulness of beef fat
• In the past few years, the tide has
shifted, and the healthfulness of
lean beef is recognized to be on
par with other protein sources
such as chicken.
• The most consumed beef product
is still, however, ground beef with
15-30% added trim fat.
• We’d like to convert the 150 lbs
from low to highly valued healthy
products.
• Our interests are in parallel development of health and
economic value
• To realize the potential, we have to pay attention along
the development continuum….
7
6
Relative Value
5
4
3
2
1
0
Commodity
Healthy fatty acid in
product
Enrichment
Fatty acid healthy
when in product
Regulatory
Acceptance
Source and Health
Claims
Nutraceutical
Beef Composition
80
Retail Survey
70
70
62
% content
60
lean beef (150 Cal/serving)
51
lean ground beef (250 Cal/serv)
regular ground beef (380 Cal/serv)
50
40
30
25
30
22
20
10
18
15
4
0
Water
Protein
Fat
Retail survey
60
50
50
45
42
% of total fat
50
lean beef (4% fat)
lean ground beef (15% fat)
40
30
20
10
5
2.5
0
SFA
MUFA
PUFA
PUFA/SFA
0.45
0.4
0.35
0.3
0.25
0.2
0.15
0.1
0.05
0
>0.4
lean beef
lean ground beef
recommended
0.12
0.06
lean beef
lean ground beef
recommended
60
50
50
% of total fat
42
50
lean beef (4% fat)
lean ground beef (15% fat)
ultra lean double muscled (0.8% fat)
32
45
40
40
30
26
20
10
5
2.5
0
SFA
MUFA
PUFA
0.9
PUFA/SFA
0.8
0.7
lean beef
0.6
lean ground beef
0.5
recommended
0.4
ultra lean beef
0.8
>0.4
0.3
0.2
0.12
0.06
0.1
0
lean beef
lean ground beef
recommended
ultra lean beef
• A more realistic way to improve the composition of beef fat
might be by adding a PUFA source to the diet.
• Flaxseed’s a good choice due to it’s high content of omega-3
fatty acids (alpha-linolenic acid)?
• Research has been done on this in the past and the results
were quite variable.
• We fed steers either 0 or 10% flaxseed in a barley grain
based diet with 20% hay for 120 days.
60
% fa y acid composi on
50
49
43
50
40
40
lean beef (75% barley,
20% hay) 120 days
30
lean beef (65% barley,
20% hay, 10 flax)
Both ~4% total fat
20
10
8
6
0
SFA
MUFA
PUFA
• When compared to a pig trial feeding 10% flax for 80
days…
60
50
49 50
43
40
40
43
38
lean beef (75% barley,
20% hay) 120 days
30
19
20
10
6
8
0
SFA
MUFA
PUFA
lean beef (65% barley,
20% hay, 10 flax)
lean pork (10% flax in
diet) 80 days
Rumen Microbes
Diet
Starch & Fibre
Low quality PTN
& NPN (eg urea)
Polyunsaturated fatty
acids (PUFA)
Rumen outflow
Volatile fatty acids
Microbial PTN &
ess. amino acids
Saturated fatty acids
PUFA Biohydrogenation = Detoxification
SOAP
Rumen bacteria
Dietary PUFA
Saturated Fat
Firm Tallow
PUFA Hydrogenation
PUFA
85-90%
Efficient
Our research is
aiming to reduce
conversion to SFA
SFA
PUFA Hydrogenation
PUFA
85-90%
Efficient
1. We try to preserve
PUFA
2. We also try to increase
healthy intermediates
like Rumenic Acid
(CLA) and Vaccenic
acid (t11-18:1)
 Anticarcinogenic
 improve blood lipid profiles
 anti-inflammatory properties
SFA
Besides CLA and VA, there are at least 30 other BH products!
PUFA
SFA
• We’re trying to figure out:
– Production strategies to change
BHP levels
– Which of these BHP are “healthy”
• This info is needed to get BHP
recognized by Health Canada and
to establish amounts needed for
things like health and enrichment
claims
Feeding studies to
Anti-mutagenic activity increase hydrogenation
(Ames Testing)
Intermediates
Dr. Yang
Cell culture: fat and
cholesterol synthesis
and inflammation
Drs. Vahmani/Dugan/Meadus
Methods for
isolating Intermed.
Dr. Dugan
Drs. Dugan/Block/Baron
Meat Quality
Sensory Properties
Hydrogenation
Intermediates
Dr. Aalhus
NIR for rapid
analysis
Drs. Prieto/Uttaro/Aalhus
Rumen
Microbiology
Drs. McAllister/Guan
Health Studies
Genomic testing
Obesity + Diabetes
Prof. Guan
Prof. Proctor
9
Feeding Studies
8
Ugly t10-18:1
Vaccenic t11-18:1
Rumenic c9,t11-CLA
7
% of total fat
6
5
4
3
2
1
0
Days
130
Concentrate 80% barley
Forage
20% grass
hay
130
120
120
120
120
220
220
250
250
200
200
70% barley
10% flax
50% barley
35% barley
15% flax
50% barley
35% barley
15% flax
30% barley
15% barley
15% flax
30% barley
15% barley
15% flax
4% barley
15% flax
4% barley
15% flax
20% grass
hay
50% barley
silage
50% barley
silage
50% grass
hay
50% grass
hay
70% red
clover sil
70% red
clover sil
70% grass/alf 70% grass/alf 70% grass 70% rcs 11%
hay
hay
11% straw
straw
– We’re still working on getting conditions right to produce high and
consistent levels of ALA BH products.
– But it’s a complex process with many interactions
Fat/Oil
Amount
Availabilit
Composition
y
Processing
Rumination
Rate of passage
Rapid Analysis
• Comprehensive analysis of beef fatty acids is done
using a combination of gas chromatography and high
performance liquid chromatography.
• It takes about 6 hr of machine time plus time for sample
and data processing.
• These methods are too slow to be used for quality
control and sorting of high value carcasses and tissues.
Rapid Analysis
• We’ve been testing NIRS (near infrared-reflectance
spectroscopy) to measure fatty acids in a few seconds.
• NIRS uses wavelengths in the NIR region (500-2500nm),
and the pattern of wavelengths reflected from samples is
used to predict composition.
• To date NIRS explains as much as 80% of the variation in
sample BHPs, and as more samples are analyzed, we’re
hoping for stronger preditions.
Rapid Analysis
• Another problem we’ve had to address is the large
amount of between animal variation we see.
• If you’re feeding flaxseed to cattle for an extended
period, it would be good to be able to sort out which
ones deposit high levels of BHP.
• We found by measuring BHP in red blood cells we can
accurately predict final tissue BHP within 2 months.
Acid in red blood cell (%total fatty acids)
% Vaccenic
% t11-18:1
4
3.5
VaccenicinAcid
% t11-18:1
Kidney Fat
3
15.2
11.9
2.5
9.8
2
1.5
7.5
7.2
1
5.7
0.5
0
1
2
3
4
5
6
Time on feed (Months)
• We now seeing if we can measure BHP in blood using
NIRS.
Rumen Microbiology
• Getting the rumen microbiology right will be a key to
high and consistent levels of BHP in beef.
• Pathways for biohydrogenation have been worked out
using bacteria isolated from the rumen
• But several other species are likely involved, haven’t
been cultured and we don’t know how they interact.
• To tackle the problem we’ve taken advantage of
advances in genomic technologies which have greatly
increased the speed and reduce the cost of DNA
sequencing.
Rumen Microbiology
• This involves pyrosequencing the 16s rRNA gene that has
species-specific signature sequences.
• Using this , we were the first to demonstrate that the
content of Vaccenic Acid in beef is correlated to 9
bacterial genera.
• We’re hoping to develop a rumen bacterial fingerprint to
identify cattle that will deposit high levels of BHP, or
develop a direct fed microbial to yield high and consistent
levels of BHP in beef.
Health Studies
• A key to developing health and economic value of beef
fat is to be able to increase the content of healthy BHP,
and show that they have value when consumed in
whole fats.
• This info is required to enable health and source claims.
• For work in this area we’ve collaborated with Prof.
Spencer Proctor who is the Director of the Metabolic
and Cardiovascular Diseases Laboratory at the U of A.
Health Studies
• We fed BHP enriched beef fat to rats
that develop obesity and diabetes.
• BHP enriched fat did not reduce blood triglycerides or
cholesterol, but did reduce fasting plasma insulin.
• Further studies are planned to establish levels of BHP
required for beneficial effects, and their mode of action.
Isolating BHP
• To determine the effects of individual BHP, you have to
be able to isolate and test them.
• We recently published a method to isolate several BHP
from beef fat using a combination of silver-ion solid
phase extraction and semi-preparative HPLC
Isolating BHP
• We’re also examining the potential to fractionate
biohydrogenation products using molecular distillation
Cell Culture Studies
• When isolating small quantities of BHP, the most convenient
way to test their effects is in cell culture.
• We’ve developed fat and liver cell culture models to do this.
• Our initial studies focused on trans fatty acids.
• Trans fatty acids have been in the news because they
increase bad cholesterol and reduce good cholesterol in our
blood.
Cell Culture Studies
• Most people studying trans fatty acids have used eladic
acid (t9-18:1), which is the most concentrated in
partially hydrogenated vegetable oil (i.e. margarine)..
• We’re interested in vaccenic acid (t11-18:1) and other
trans fatty acids found in beef fat when feeding forages
or flaxseed.
Cell Culture Studies
• We’ve found in cell culture the “ugly” trans turn on genes
fat and cholesterol synthesis
RNA Micro -Array
• BUT other trans found when feeding flax (t11-, t13-, t14-,
t15- and t16-18:1) don’t, and their effects are similar to
oleic acid (major FA in olive oil).
• We’re continuing our work to characterize the effects of
the trans fatty acids, and starting work with other BHP
with more complex structures (i.e. dienes and trienes).
Study Support:
Peer Review Program
Collaborators
Dave
Rolland
Jon
Meadus
Payam
Vahmani
Nuria
Prieto
Jennifer
Aalhus
Tim
McAllister
Bethany
Uttaro
Spencer
Proctor
Cletos
Mapiye
Hushton
Block
Vern
Baron
Tyler
Turner
Xianqin
Yang
Leluo
Guan
• The cast of many others from the the beef unit, abattoir
and meat labs that do much of the hard work…