Asia Pacific J Clin Nutr (1993) 2, 155-163
The trans fatty acid and positional
(sn-2) fatty acid composition of some Australian margarines, dairy
blends and animal fats
M.P. Mansour* and A.J. Sinclair**
*School of Nutrition and Public Health,
Deakin University, Geelong, Australia; **Department of Applied Biology
and Biotechnology, Royal Melbourne Institute of Technology, Melbourne,
Australia.
We have analysed the fatty acid (FA) composition
including the trans fatty acid by GLC and Fourier Transform Infra-Red
(FTIR) Spectrophotometry of 13 margarines, five butter/dairy blends
and two animal fats (lard and dripping). The samples were purchased
from supermarkets in three separate locations across Victoria: Gladstone
Park (near Melbourne), Waurn Ponds (near Geelong) and Geelong city.
From the FA composition, the P/S, P/(S+trans monoenoic FA), P/M(S+trans
monoenoic FA) and w6/w3 ratios were calculated. The FA composition
and trans FA content were compared with the last published analysis
of Australian margarines in Sydney in 1982. The FA composition of
the sn-2 position was obtained by pancreatic lipase deacylation
of the whole triglycerides (TG) . From this data, we estimated the
per cent interesterified fat which was present in the margarines.
The trans FA content of the margarines which was determined by FTIR
ranged from 9.2% to 16.3% (mean of 13.1% of total FAME) (7.6 g-13.0
g trans FA/100 g sample, mean of 10.4 g/100 g sample) and from 3.2%
to 4.1% (mean of 3.8%) for butter and dairy blends. Lard contained
0.4% trans FA while dripping consisted of 3.6% trans FA. The trans
FA content in the margarines was similar to the values published
in 1982 with the exception of four brands. The w6/w3 ranged from
2.5 to 363 and the P/S ranged from 1.4 to 3.3 compared with the
1982 figures where the w6/w3 ranged from 3 to 49 and the P/S ranged
from 0.1 to 3.7. The estimated per cent interesterified fat in the
margarines ranged from 25% to 100%. We estimated the total trans
FA intake in the Australian diet to be between 2.7 g/head/day and
4.8 g/head/day. We also estimated that table margarines account
for between 36% and 64% of the total trans FA intake in the Australian
diet.
Introduction
Trans FAs are formed during the partial hydrogenation
of vegetable oils1-4 which are used for the manufacture
of margarines and processed foods. Trans FA also occurs in milk fat,
butter and ruminant fats such as tallow and dripping (lamb and beef
fat, respectively)1,2,4. Trans FA may also be present in
fat from non-ruminant animals that consume diets containing trans
FA1. In recent times there has been growing concern as
to the possible detrimental effects of consumption of trans FA on
human health2-9.
Dietary trans FAs have been shown to increase plasma
LDL cholesterol 10-14 while decreasing plasma HDL cholesterol
levels10-15. Plasma lipoprotein (a) which is thought to
be an indicator of atherogenic risk has also been shown to rise with
increasing intake of trans FA16,17. As a result of these
observations trans monoenoic FAs, which are the major trans FA isomers
found in margarines are now being considered at least as harmful as
saturated fatty acids12,14,18.
Trans FAs accumulate in a variety of tissues in different
amounts with adipose tissue containing the highest level19.
Trans FA isomers have also been detected in human breast milk
and it has been suggested that these levels may be affected by the
mother's diet20,21. Recent reports have shown that trans
FA isomers of 18:3 may be metabolized to trans docosahexaenoic acid
which can be detected in the brain lipids of rats fed trans 18:322.
The amount of trans FA in margarines depends on the
extent of hydrogenation and whether or not the partially hydrogenated
vegetable oil is blended with interesterified, animal or dairy fat.
The main determinants in the above processes are the availability
and cost of the seed oils, animal and dairy fats, in addition to the
desired consistency of a particular product.
Several workers have indicated that, irrespective
of fatty acid composition, the distribution of FA in the triglyceride
structure effects cholesterolaemia. Thus there have been suggestions
that linoleic acid is more hypocholesterolaemic23 and stearic
acid more hypercholesterolaemic24 when present at the sn-2
position, than when esterified in positions sn-1 or sn-3. The fact
that stearic acid is normally esterified at position 1 and rarely
at position 2 may partly explain the apparent 'neutral' effect of
stearic acid on blood cholesterol.
A Belgian research group reported that butter was
less hypercholesterolaemic if the triglyceride FA were randomized
by the technique of interesterification25. Butter contains
a high proportion of 14:0 and 16:0 FA in the sn-2 position and the
interesterification process would reduce the proportion in the 2-position,
since interesterification evenly distributes the FA in each of the
sn-positions in the TG. Kritchevsky et al.26 have shown
that the atherogenic effects of peanut oil for rats could be reduced
if the peanut oil was interesterified.
While the mechanisms of these effects are still obscure,
nevertheless the results highlight the importance of the positional
distribution of FA in the TG. It has been suggested by Redgrave et
al.27 that saturated FA in the sn-2 position reduced chylomicron
remnant metabolism, a process which has been implicated in atherosclerosis.
Ahikari et al.28 have been able to use two FA ratios, namely,
the ratio of palmitic acid in the sn-2 position to that found in the
whole triglyceride and similarly the amount of total saturated fatty
acids in the sn-2 position to that found in the whole triglyceride
(R1 and R2, respectively) to estimate the amount of interesterified
fat added to a hydrogenated fat. Carpenter et al.29 have
been able to show that trans monoenoic FAs are concentrated in the
sn-2 positions in some margarines. This observation has been attributed
to polyunsaturated FAs being preferentially located in the sn-2 position
of the original vegetable oil which are partly converted to trans
monoenoic FA during hydrogenation.
Several analyses of Australian margarines (197682)30-33
have reported values of trans FA which were lower (less than 15%)
than those from other western countries notably America (10-30% in
1984)34, Canada (10-35% in 1985)35, Britain
(4-42% in 1984)36 and up to 50% in northern Europe where
partially hydrogenated marine oils were used in the formulation of
some cheaper margarines37.
The last analysis of trans FA in Australian margarines
was carried out in 198233. Owing to the potential variability
in margarine formulations and an upsurge in the interest in trans
FA there was a need to analyse the currently produced margarines in
the Australian marketplace, determine the trans FA content and sn-2
FA composition and estimate the extent to which interesterified fats
were added to partially hydrogenated vegetable oils.
Methods
(All standards and reagents were of 99.9% purity and
analytical grade, respectively, unless otherwise stated).
Validation
for selection of number of tubs to be analysed
Margarines from three different locations were sampled
and initially two tubs were purchased from each location. Duplicate
determinations of trans FA content were performed on each tub. We
found that the average per cent trans FA content of the first tubs
collected from the three locations (10.32 ± 0.28% for six determinations) was
very similar to the average per cent trans FA content of the first
and second tubs collected from the three locations (10.10 ± 0.40% for twelve determinations). From these results it was concluded
that sampling three tubs, one from each location (six determinations)
was sufficient.
Sample
collections
After collecting one tub from each location, they
were coded, dated and stored in a refrigerator at 4°C until required
for analysis. Three tubs of an olive oil-based margarine manufactured
in Greece (Brio brand) obtained as a gift from Unilever Australia
Ltd were also analysed.
Subsampling
for analysis
The top 1 cm surface layer was discarded and a core
sample of approximately 2 g was taken from two locations in the tub
at least 3 cm apart and placed in a 15 mL test tube with a teflon-lined
screw cap.
Extraction
of lipid
The sample was extracted into petroleum ether (PE)
(1 x 10mL then 2x5 mL) with shaking/vortex mixing and centrifugation
each time. Effectively all the lipid was extracted by this method
as a further chloroform/ methanol (2/1, v/v) re-extraction of the
residue yielded no detectable lipid. The extract was transferred and
made up to volume in a 25 mL standard flask.
Gravimetric
determination of per cent lipid
Aliquots of 1 mL were taken from the 25 mL stock and
delivered into pre-weighed glass vials. The PE was evaporated in a
stream of nitrogen. The dry extract was stored overnight in a dessicator
over silica gel and reweighed the following day.
Fatty acid
analysis
Saponification
and methylation
A 0.5 mL aliquot from the lipid stock solution and
a 1.0 mL aliquot of triheptadecanoin internal standard (13.0 mg/mL)
in chloroform were taken and delivered into test tubes with teflon
lined screw caps. The solvent was evaporated in a stream of nitrogen
and 2 mL of potassium hydroxide in methanol KOH/MeOH (58 mg/mL) was
added. The contents of the tube were flushed with nitrogen, quickly
capped and placed in a fan-forced oven set at 105°C. After 10 min,
2 mL of 20% boron trifluoride in methanol (BF3/MeOH) was
added and the tube reheated for 10 min at 105°C. The fatty acid methyl
esters (FAME) were then extracted into the PE. The FAME were then
washed with distilled water and dried over anhydrous sodium sulphate.
The FAME were chromatographed immediately or stored at -20°C until
required for analysis.
Gas
liquid chromatography (GLC)
The FAME were separated on a 50 m BPx70 (0.32 mm ID
and 0.25 mm film thickness) bonded phase, fused silica capillary column
(SGE Ringwood, Victoria, Australia), connected to a Shimadzu GC-9A
chromatograph which was interfaced to a Shimadzu CR4A microprocessor
integrator used for data storage and handling. The injector and FID
detector temperatures were both 280°C and the linear carrier gas (Helium)
flow was set to 20 cm/sec. The column oven was set at an initial temperature
of 110°C for 3 min and was then increased at 1°C/min until a temperature
of 170°C was reached. The rate was then increased to 5°C/min and the
final temperature of 200°C was maintained for 30 min.
Total
methylene interrupted trans fatty acids by FTIR
This method is based on an IUPAC official method38.
The remaining 21.5 mL of the lipid stock was saponified by refluxing
with 20 mL of KOH/MeOH (58 mg/mL) for 10 min. 20 mL of BF3/MeOH
(20%) was then added and the mixture refluxed for a further 10 min.
When the mixture had cooled 20 mL of PE and 20 mL of saturated sodium
chloride solution were added, the flask stoppered and the mixture
shaken to extract the FAME into the PE phase. After the layers had
separated the FAME were siphoned into a 50 mL round-bottomed flask
and concentrated on a rotary evaporator at 35°C.
The FAME were purified by eluting through a silica
sep-pak (Millipore-Waters) with 10% diethylether (DE) in PE into a
pre-weighed 10 mL volumetric flask. The solvent was evaporated in
a stream of nitrogen and the flask re-weighed to calculate the mass
of FAME. The FAME were diluted to the mark with carbon disulphide
(CS2). A 2 mL aliquot was further diluted to 5 mL prior
to measuring the IR absorbance.
A series of calibration standards made up of elaidic
and stearic acid methyl esters were obtained by bulk methylation of
the free fatty acids (Nu Chek Prep, Minnesota, USA) and purified by
silica column chromatography using PE as the eluting solvent. The
purity was rechecked by thin layer chromatography (TLC) before drying
the FAME with nitrogen. The standard solutions were then used to construct
a calibration curve. A CS2 filled sodium chloride cell
of 1 mm path length was used as the background blank.
The IR absorbance peak area at 970 cm-1
was measured on a FTIR spectrophotometer (FTS-7) (Biorad Laboratories,
Digilab Division, Hercules, CA, USA) using the quantitation software
(Interquant). The concentration of the total methylene interrupted
trans FAME was interpolated from the calibration curve.
Positional
(sn-2 FA) analysis of triglycerides
The purification of the TG was achieved by preparative
TLC of 400 m L of the lipid stock solution on two TLC plates (200 m L on each plate). The plates were
then developed in a solvent system consisting of PE/DE/ glacial acetic
acid (90/10/1 v/v/v). After the development the plate was sprayed
with 2'7'-dichlorofluoroscein in MeOH and the TG band visualized and
marked under a 360 nm UV lamp. The silica gel was then scraped off
the plate and placed into a methylation tube and extracted with 10%
DE in PE (3 x 5 mL). The extracts were combined and dried in a stream
of nitrogen then reconstituted in 400 m L of PE.
Pancreatic
lipase deacylation
All reagents used in this section were purchased from
the Sigma Chemical Company (St Louis, MO, USA). This method is based
on the procedure of Chacko et al.39 Approximately 10 m L of the purified TG (10 m L/400 m L) was dried with nitrogen in a methylation
tube to which 100 m L of CaCl2 (22 mg/mL), 250 m L of bile salts (cholate/ deoxycholate, 0.5 mg/mL) and 1 mL of pancreatic
lipase (porcine, type II, crude, Sigma, 21.23 mg/mL) in Trizma buffer
(Tris base, pH8). The reaction mixture was incubated at 40°C for 0.5
min then the reaction was stopped with 0.5 mL of 6M HCl. The lipase
reaction was repeated using 1.0 min and 1.5 min incubations.
After extracting into DE, washing and drying as previously
achieved for the FAME, the reaction mixture was examined on TLC using
a developing solvent system of PE/DE/glacial acetic acid (85/15/ v/v/v).
The plate was then sprayed with 10% CuS04 in 8% H3PO4
(w/v) and charred at 140°C for 30 min.
An incubation time was selected to achieve a 50-60%
hydrolysis which would provide a sufficient amount of monoglycerides
(MG). If the lipase hydrolysis continues beyond the optimum time some
migration of FA between sn-1, 2 and 3 positions may occur in the MG40,41.
The optimum incubation time varied between 0.5 and 1.5 min for the
various fats analysed.
Results
The measured per cent lipid of the margarines was
at least what was stated on the tubs and ranged between 81% and 86%
which was similar to the 1982 levels (79-84%). In the case of the
dairy blends the per cent lipid ranged between 83% and 85% except
for one low-fat brand. Lard and dripping each contained 100% lipid
(see Table 1).
Table 1. The lipid content of margarines, butter/dairy
blends and animal fats.
| Sample |
Code |
%Lipid |
| Margarines |
| Gold'n Canola |
GC |
85.5 |
| Nuttlex |
NUT |
84.7 |
| Miracle |
M |
82.9 |
| Miracle Canola |
MCAN |
83.1 |
| Meadow Lea |
ML |
81.1 |
| Meadow Lea Canola |
MLCAN |
81.9 |
| ETA |
ETA |
84.3 |
| Flora |
Flora |
82.4 |
| Daffodil |
DAF |
82.6 |
| Becel |
BEC |
85.7 |
| Brio |
BRIO |
81.0 |
| Home Brand Margarine |
HBM |
83.0 |
| Mrs McGregor's |
MAC |
82.6 |
| Butter/Dairy Blends |
| Western Star Butter |
WSB |
83.2 |
| Western Star Country
Gold |
WSCG |
83.0 |
| Devondale Dairy Soft |
DDS |
83.1 |
| Devondale Dairy Canola |
DDC |
60.9 |
| Prefer |
PRE |
84.7 |
| Animal Fat |
| Lard |
LAR |
100 |
| Dripping |
DRIP |
100 |
Mean (n=6).
Figure 1 shows the typical chromatograms of a margarine
and butter sample. It can be seen that the major trans FA and cis
positional isomers are trans 18:1 positional isomers (tentatively
identified as 9 trans, 10 trans and 11 trans, cis 18:1 positional
isomers (tentatively identified as 9 cis, 10 cis and 11 cis), smaller
amounts of trans 18:2 isomers and possibly trans 18:3 isomers. The
amounts of these various isomers varied between the different brands
of margarines. The FA composition of the margarines is shown in Table
2 and Table 3. The FA composition of the butter/dairy blends was more
complex than that of the margarines in terms of having more short
chain and branched FA as can be seen in Table 4. The FA composition
of the animal fats was less complex than that of the dairy blends
(see Table 4).
Figure 1a. A GLC trace of a margarine (MLCAN)
showing the main trans 18:1 and cis 18:1 positional isomers (tentative
identification) .
Figure 1b. GLC trace of a butter (WSB) showing
differences in the amount and type of cis and trans 18:1 positional
isomers.
Table 2. Fatty acid composition (% of total
FA) in the sn-2 position of TG and of total margarinesa.
| FA |
BECEL |
ML |
MLCAN |
M |
MCAN |
BRIO |
| |
Total
FA |
sn-2
FA |
Total
FA |
sn-2
FA |
Total
FA |
sn-2
FA |
Total
FA |
sn-2
FA |
Total
FA |
sn-2
FA |
Total
FA |
sn-2
FA |
| 10:0 |
ndb |
0.60 |
nd |
021 |
nd |
0,03 |
nd |
0.39 |
nd |
0.08 |
nd |
nd |
| 12:0 |
nd |
0.48 |
nd |
0.17 |
nd |
0.03 |
0.09 |
0.50 |
nd |
nd |
nd |
nd |
| 14:0 |
0.08 |
1.77 |
0.23 |
0.80 |
0.18 |
0.46 |
0.35 |
1.07 |
0.08 |
0.52 |
nd |
nd |
| 16:0 |
6.13 |
10.74 |
11.25 |
5.22 |
8.26 |
2.70 |
13.54 |
6.96 |
6.41 |
5.76 |
11.26 |
3.82 |
| 16:1 |
0.06 |
0.15 |
0.08 |
nd |
0.16 |
nd |
0.07 |
nd |
0.14 |
0.31 |
0.48 |
nd |
| 17:0 |
nd |
0.86 |
nd |
0.54 |
0.27 |
nd |
nd |
0.34 |
nd |
0.66 |
nd |
nd |
| 17:1 |
nd |
nd |
nd |
nd |
nd |
nd |
nd |
nd |
nd |
nd |
nd |
nd |
| 18:0 |
6.10 |
11.65 |
7.38 |
7.36 |
4.88 |
4.56 |
5.46 |
5.78 |
6.35 |
9.06 |
8.36 |
6.79 |
| t-18:1c |
7.51 |
5.67 |
13.20 |
11.77 |
8.83 |
11.18 |
12.11 |
12.84 |
13.22 |
9.74 |
12.78 |
14.14 |
| 18:1 |
31.00 |
31.33 |
24.59 |
24.33 |
48.32 |
49.06 |
25.18 |
29.84 |
51.47 |
42.34 |
61.19 |
64.90 |
| t-18:2 |
0.97 |
1.93 |
0.54 |
0.37 |
0.42 |
0.70 |
0.66 |
0.89 |
1.08 |
1.14 |
nd |
nd |
| 18:2 |
44.29 |
28.82 |
39.05 |
38.10 |
15.51 |
23.96 |
39.48 |
39.00 |
15.75 |
21.78 |
4.90 |
7.53 |
| t-18:3 |
0.02 |
0.70 |
0.09 |
0.11 |
0.37 |
0.42 |
0.09 |
nd |
0.22 |
0.52 |
nd |
nd |
| 18:3 |
1.97 |
1.47 |
2.02 |
1.46 |
38.10 |
15.51 |
2.19 |
1.40 |
5.80 |
5.13 |
0.41 |
0.62 |
| 20:0 |
0.52 |
0.52 |
0.46 |
0.23 |
0.53 |
0.11 |
0.43 |
0.19 |
0.68 |
0.18 |
0.45 |
nd |
| t-20:1 |
nd |
0.32 |
0.14 |
0.13 |
nd |
0.12 |
0.01 |
nd |
nd |
nd |
nd |
nd |
| 20:1 |
0.38 |
0.42 |
0.29 |
0.18 |
0.76 |
0.32 |
0.22 |
nd |
0.78 |
0.32 |
0.17 |
nd |
| 22:0 |
0.78 |
0.34 |
0.52 |
0.83 |
0.31 |
nd |
0.55 |
0.20 |
0.33 |
0.20 |
nd |
nd |
| 22:1 |
nd |
2.03 |
0.02 |
7.90 |
0.14 |
nd |
nd |
1.09 |
nd |
2.26 |
nd |
nd |
| 24:0 |
0.25 |
0.20 |
0.21 |
0.28 |
0.32 |
0.31 |
0.19 |
nd |
0.18 |
nd |
nd |
nd |
| 24:1 |
nd |
nd |
nd |
nd |
nd |
nd |
nd |
nd |
0.12 |
nd |
nd |
nd |
aMean (n=6)
b nd (not detected)
c t-18:1 = 9t-18:1 + 10t-18:1 + 11t-18:1.
Table 3. Fatty acid composition (% of total
FA) in the sn-2 position of TG and of total margarinesa.
| FA |
MAC |
HBA |
FLORA |
DAF |
ETA |
GC |
NUT |
| |
Total
Fa |
sn-2
FA |
Total
FA |
sn-2
FA |
Total
FA |
sn-2
FA |
Total
FA |
sn-2
FA |
Total
FA |
sn-2
FA |
Total
FA |
sn-2
FA |
Total
FA |
sn-2
FA |
| 10:0 |
ndb |
nd |
0.08 |
0.32 |
nd |
nd |
nd |
0.59 |
nd |
nd |
nd |
nd |
nd |
nd |
| 12:0 |
nd |
nd |
0.10 |
0.29 |
0.03 |
nd |
0.26 |
0.62 |
0.17 |
0.42 |
nd |
nd |
nd |
0.23 |
| 14:0 |
0.64 |
1.30 |
0.22 |
1.47 |
0.29 |
0.51 |
0.29 |
1.62 |
0.24 |
1.20 |
0.21 |
0.51 |
0.28 |
0.98 |
| 16:0 |
20.73 |
11.00 |
10.81 |
10.45 |
12.34 |
6.17 |
12.73 |
10.43 |
10.44 |
7.23 |
9.09 |
2.24 |
13.14 |
6.83 |
| 16:1 |
0.31 |
0.32 |
0.08 |
0.29 |
0.07 |
nd |
0.03 |
0.20 |
0.06 |
nd |
0.21 |
0.16 |
nd |
0.20 |
| 17:0 |
nd |
0.46 |
nd |
0.34 |
nd |
0.24 |
nd |
0.77 |
nd |
0.34 |
nd |
0.25 |
nd |
0.79 |
| 17:1 |
nd |
nd |
nd |
nd |
nd |
nd |
nd |
nd |
nd |
nd |
nd |
nd |
nd |
nd |
| 18:0 |
5.96 |
12.56 |
7.42 |
8.97 |
5.33 |
6.11 |
4.97 |
10.99 |
7.18 |
8.48 |
5.00 |
3.25 |
5.96 |
7.56 |
| t-18:1c |
13.51 |
10.74 |
9.66 |
8.10 |
13.24 |
14.49 |
11.62 |
10.40 |
13.59 |
12.09 |
7.73 |
9.09 |
10.98 |
11.14 |
| 18:1 |
19.30 |
25.75 |
24.33 |
27.08 |
23.89 |
29.40 |
22.16 |
27.95 |
25.81 |
28.86 |
54.58 |
48.38 |
27.29 |
33.23 |
| t-18:2 |
0.70 |
0.58 |
1.36 |
0.50 |
0.44 |
0.32 |
0.50 |
0.99 |
0.73 |
0.65 |
nd |
0.22 |
0.67 |
1.09 |
| 18:2 |
37:48 |
30.42 |
44.65 |
36.17 |
40.81 |
38.45 |
44.02 |
30.36 |
38.63 |
35.05 |
15.11 |
25.62 |
39.92 |
32.77 |
| t-18:3 |
0.14 |
1.53 |
nd |
0.23 |
0.06 |
0.69 |
nd |
0.61 |
0.08 |
0.26 |
0.28 |
0.58 |
0.11 |
0.57 |
| 18:3 |
0.15 |
1.06 |
0.74 |
1.76 |
1.84 |
1.48 |
1.44 |
1.25 |
1.42 |
1.51 |
5.71 |
8.50 |
0.11 |
0.64 |
| 20:0 |
0.42 |
0.33 |
0.39 |
0.36 |
0.65 |
0.18 |
0.46 |
0.47 |
0.49 |
0.31 |
0.58 |
0.10 |
0.34 |
0.29 |
| t-20:1 |
0.18 |
0.27 |
nd |
0.37 |
0.07 |
nd |
nd |
0.08 |
0.14 |
0.67 |
nd |
0.13 |
nd |
nd |
| 20:1 |
0.20 |
0.34 |
0.13 |
0.40 |
0.22 |
0.55 |
0.18 |
0.34 |
0.31 |
0.27 |
0.97 |
0.18 |
0.11 |
0.66 |
| 22:0 |
0.17 |
0.25 |
0.61 |
0.26 |
0.54 |
0.16 |
0.57 |
0.29 |
0.52 |
0.18 |
0.28 |
nd |
0.54 |
0.25 |
| 22:1 |
nd |
3.29 |
0.28 |
2.63 |
0.01 |
1.24 |
nd |
2.03 |
nd |
2.48 |
nd |
0.81 |
nd |
2.38 |
| 24:0 |
0.10 |
nd |
0.20 |
nd |
0.19 |
nd |
0.20 |
nd |
0.20 |
nd |
nd |
nd |
nd |
0.13 |
| 24:1 |
nd |
nd |
nd |
nd |
nd |
nd |
nd |
nd |
nd |
nd |
nd |
nd |
nd |
0.24 |
a Mean (n=6)
b nd (not detected)
c t-18:1 = 9t-18:1 + l0t-18:1 + 11t-18:1.
Table 4. Fatty acid composition (% of total
FA) in the sn-2 position of TG and of total butter/dairy blends and
animal fatsa.
| FA |
WSB |
WSCG |
DDS |
DDC |
PRE |
LAR |
DRIP |
| |
Total
FA |
sn-2
FA |
Total
FA |
sn-2
FA |
Total
FA |
sn-2
FA |
Total
FA |
sn-2
FA |
Total
FA |
sn-2
FA |
Total
FA |
sn-2
FA |
Total
FA |
sn-2
FA |
| 8:0 |
0.69 |
0.54 |
0.68 |
ndb |
0.75 |
nd |
0.45 |
nd |
0.71 |
0.69 |
nd |
nd |
nd |
nd |
| 10:0 |
2.38 |
0.52 |
2.26 |
0.51 |
2.26 |
0.11 |
1.67 |
0.23 |
2.13 |
0.19 |
nd |
0.19 |
nd |
0.22 |
| 10:0 |
0.21 |
0.13 |
0.16 |
nd |
0.16 |
nd |
nd |
nd |
0.17 |
nd |
nd |
nd |
nd |
nd |
| 12:0 |
3.11 |
2.84 |
2.95 |
1.55 |
2.67 |
1.54 |
2.12 |
1.59 |
2.60 |
0.90 |
0.08 |
0.33 |
0.15 |
0.22 |
| 13:0 |
0.07 |
0.12 |
nd |
nd |
0.07 |
0.15 |
nd |
nd |
nd |
nd |
nd |
nd |
nd |
nd |
| 14:0 |
11.45 |
17.07 |
9.47 |
8.64 |
8.60 |
9.26 |
7.55 |
9.39 |
9.11 |
28.37 |
1.62 |
2.20 |
4.14 |
2.72 |
| 14:1 |
0.83 |
0.63 |
0.65 |
0.26 |
0.54 |
0.32 |
0.43 |
0.22 |
0.65 |
0.20 |
nd |
0.16 |
0.77 |
nd |
| 15.0 |
1.10 |
1.47 |
0.88 |
0.74 |
0.79 |
0.80 |
0.66 |
0.80 |
0.90 |
0.80 |
0.13 |
0.29 |
0.58 |
0.28 |
| 16:0 |
28.84 |
37.33 |
22.56 |
23.00 |
21.39 |
23.42 |
19.17 |
24.97 |
23.81 |
24.17 |
27.48 |
47.70 |
26.52 |
12.55 |
| 16:1 |
1.23 |
1.70 |
0.89 |
0.83 |
0.81 |
0.88 |
0.82 |
0.90 |
0.99 |
0.96 |
2.02 |
0.87 |
3.12 |
3.27 |
| 17:0 |
nd |
0.78 |
nd |
0.75 |
nd |
0.56 |
nd |
0.77 |
nd |
0.60 |
nd |
1.12 |
nd |
0.58 |
| 17:1 |
0.26 |
0.36 |
0.19 |
nd |
0.17 |
0.20 |
0.21 |
nd |
0.16 |
0.36 |
0.46 |
0.19 |
0.66 |
0.63 |
| 18:0 |
11.29 |
7.30 |
11.21 |
11.47 |
11.39 |
9.42 |
9.85 |
10.09 |
11.95 |
8.66 |
16.48 |
10.23 |
18.02 |
11.33 |
| t-18:1c |
3.35 |
2.60 |
3.09 |
2.88 |
3.36 |
3.34 |
2.34 |
2.39 |
2.71 |
4.23 |
0.34 |
2.24 |
3.10 |
1.64 |
| 18:1 |
19.58 |
16.84 |
22.69 |
25.78 |
22.70 |
22.98 |
38.46 |
29.20 |
23.67 |
22.46 |
39.20 |
18.66 |
36.92 |
47.18 |
| t-18:2 |
0.38 |
1.04 |
0.87 |
0.26 |
0.90 |
1.01 |
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