An edible fat spread is provided that comprises triglyceride fat the fatty acid residues of which include 0.05-20 wt % conjugated linoleic acid (CLA) residues. The spread has sensoric properties as good as corresponding spreads without CLA and can be used as a normal part of a daily diet while it can contribute to obtaining an improved blood lipid profile.

FIELD OF THE INVENTION 
The invention relates to an edible fat spread. More particularly, the 
invention relates to a fat spread having an effective form of conjugated 
linoleic acid. 
BACKGROUND OF THE INVENTION 
Fatspreads are products containing a fat phase and often also an aqueous 
phase. Fat continuous examples of such fatspreads are plastic shortenings, 
margarines, butter and reduced fat variants of margarine and butter. In 
such fat-continuous products the fat phase comprises oil in the liquid 
state and a network of fat crystals, which largely determine the 
rheological properties of the product. Spreads having a continuous aqueous 
phase and a dispersed fat phase that have plastic rheology and are 
suitable for spreading e.g. on bread or toast, are known as well. Also 
bi-continuous spreads have been developed. If the spread has a continuous 
aqueous phase, the aqueous phase is structured with hydrocolloids, e.g. 
gums and/or modified starches to obtain plasticity. The invention also 
relates to a process for preparing the edible fat spread. 
In 1979 it was found that uncooked and pan-fried ground beef can have 
antimutagenic activity. (Cancer Lett. (1979), 7, 63-69). In 1987 it was 
reported that the active substance were isomers of conjugated linoleic 
acid (CLA). This activity of CLA was confirmed in that inhibition of mouse 
skin carcinogenesis was observed (Carcinogenesis, (1987), 8(12), 
1881-1887. It was further found that mammary tumors in rats and mouse 
forestomach neoplasia are suppressed by dietary CLA (Cancer Res. (1991), 
51(22), 6118-6124 and Cancer Res. (1990), 50, 1097-1101). In the article 
it was suggested that the active form of CLA is CLA incorporated in 
phospholipid. 
Work continued, studying the underlying mechanisms and aiming to put the 
findings to practical use. U.S. Pat. No. 5,208,356 reports amongst other 
things anti-oxidant activity of CLA. 
A strong preference is expressed for CLA incorporated into phospholipid. 
U.S. Pat. No. 5,070,104 reports that CLA is effective for chelating 
metals. The preferred forms of CLA are CLA itself, methyl and ethyl esters 
and sodium and potassium salts of CLA. Chelating metals can be put to use 
both in vivo and in vitro. For in vivo application, pharmaceutical 
composition comprising an active form of CLA, notably non-toxic salts, are 
disclosed. 
Recently, it was further reported that including CLA in the diet of rabbits 
and hamsters can have a beneficial effect on the blood lipids profile: it 
reduces the content of total cholesterol, LDL cholesterol and 
triglycerides without adverse effect on HDL cholesterol (Atherosclerosis 
(1994), 108, 19-25 and Circulation Suppl I (1993), 88, 45) 
SUMMARY OF THE INVENTION 
An edible fat spread containing a fat phase and optionally an aqueous phase 
is described. The fat of the fat phase comprises triglycerides of fatty 
acid residues of which 0.05-20% by weight consist of conjugated lineolic 
acid residues and of which at most 50% by weight consist of saturated and 
trans-unsaturated fatty acid residues, other than conjugated linoleic 
acid. 
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
We have now found that a beneficial effect with respect to the bloodlipids 
profile can be obtained using CLA with the diet, but using a form in which 
the CLA becomes an integral part of the diet. According to our invention 
the CLA containing composition is not an addition to the regular diet 
which raises caloric intake but a normal constituent of the diet wherein 
CLA replaces fat. Furthermore, many consumers do not wish to take 
medicine-like products or dietary supplements on a regular basis. Yet, 
cardio vascular disease, for which the blood lipid profile is a risk 
indicator, is one of the main causes of death in affluent societies. Many 
people, also many of those who do not have an identified elevated risk of 
heart failure, would benefit from an improved blood lipids profile. 
However, such consumers typically do not accept products that provide a 
health benefit as part of their daily diet, unless such products do not in 
any way detract from the pleasure derived from using and eating the 
product. 
We found a way to obtain beneficial effects on blood lipids by means of a 
product that constitutes a normal part of a regular diet and thus does not 
add calories and that is in no way less attractive in sensorically 
perceivable properties than conventional products of the same type that do 
not have the favourable effect on blood lipids. Accordingly, the invention 
provides an edible fat spread containing a fat phase and optionally an 
aqueous phase, wherein the fat of the fat phase comprises triglycerides of 
fatty acid residues of which 0.05-20% by weight consist of conjugated 
linoleic acid residues, and of which at most 50% by weight consist of 
saturated and trans unsaturated acid residues other than CLA. 
Much resource has been devoted to analysis of CLA contents in foodproducts. 
Although there is much controversy about the accuracy and reliability of 
the results of the analyses, there seems to be consensus that the highest 
levels of CLA are found in foodproducts of which the fat originates from 
ruminants e.g. beeffat and milkfat. Furthermore, within this group, the 
highest levels seem to be found for the type of products that are 
subjected to substantial heating during their preparation, notably 
processed cheese and grilled ground beef. For example, J. Agri Food Chem. 
37(1), (1989), 75-81, reported that ground beef contained 562 ppm of CLA 
while grilled ground beef contained 998 ppm of CLA. The CLA content of 
different cheeses ranged form 169 ppm to 1815 ppm, while the CLA content 
of whole milk was 28 ppm. Calculated with respect to the fat, the 
variation in this group of products of which the fat originates from 
ruminants, was smaller: from 550 to 9290 ppm CLA for blue cheese and 
grilled ground beef, respectively. JAOCS 69(5), (May 1992), 425-428 
reports CLA contents of a variety of processed cheeses between 3.2 and 8.9 
mg/g fat. 
From the above cited literature it appears that the presence of 0.05 en % 
of CLA in the diet is sufficient to get notable health benefits e.g. with 
respect to blood lipids levels (although in some studies substantially 
higher dosages have been applied). If this is so, in view of the above 
given analysis, it would be expected that the CLA present in dairy and 
beef products, considering the amounts in which they are generally 
consumed, is sufficient to reduce blood cholesterol levels. Yet, this is 
not so. To the contrary, it is widely accepted that, in order to reduce 
blood cholesterol levels, consumption of beef and dairy fat should be 
reduced rather than increased. There seem to be two possible explanations 
for this apparent paradox: 
The above analyses of beef and dairy products do not allow drawing 
conclusions about the form in which CLA is present. It can be hypothesized 
that only CLA in a particular form, e.g. as free CLA or in phospholipid 
form is effective. Most studies on in vivo effects were done with CLA 
present as free acids. The literature recommends to use CLA e.g. in the 
form of phospholipid, free CLA or sodium or potassium salts. 
The CLA in beef and dairy products does have a favourable effect, but this 
is overshadowed by the adverse effects of the other constituents of beef 
and dairy fat. Beef and dairy fat predominantly consist of saturated and 
trans-unsaturated (other than CLA) fatty acid residues. 
We have found that CLA in the form of triglycerides can be effective in 
improving the blood lipids profile. Furthermore, in our product the amount 
of saturated and trans unsaturated fatty acid residues other than CLA is 
less than 50%, calculated on the fat of the product. 
Preferably, the content of saturated and trans-unsaturated fatty acid 
residues other than CLA is substantially lower, e.g. less than 40%, more 
preferably less than 30%, and most preferably less than 25%. 
For example, to provide on average 0.05 en % of CLA in the diet, for a 
typical diet, an amount of about 1% CLA-residues in the fat of a spread 
containing 60% fat phase and 40% aqueous phase would be appropriate. 
Incorporating such an amount in the form of phospholipid ester would 
correspond to about 3% of phospholipid calculated on the amount of fat. We 
found that incorporating such an amount of the phospholipid in the spread 
has a quite noticeable negative effect on the mouthfeel and melting 
behaviour of the product and its flavour release. We further found that 
including 1% CLA as free acid had a perceivable adverse effect on the 
taste of the product. Such free acid we found, also affects the 
keepability of the product. It enhanced hydrolysis and development of 
rancidity, which are clearly undesirable phenomena. Using CLA in the form 
of salts such as sodium and potassium salts, had a strong negative effect 
on the taste of the product even at much lower levels than 1%. No such 
adverse effects on the sensorically perceivable product properties are 
observed when incorporating the CLA as fatty acid residues esterified in 
triglycerides. 
A further advantage of the invention is that the amount of CLA incorporated 
can easily be adjusted within wide ranges, depending on the product design 
and eating habits and medical condition of particular consumer groups. 
Preferably however the content of CLA residues in the fatty acid residues 
of the fat is 0.1-15%, more preferably 0.5-10%. 
Preferably the CLA residues of the product comprise at least 50%, more 
preferably at least 75% of residues of the 9,11 octadecadienoic acid 
and/or 10,12 octadecadienoic acid isomers. It is further preferred that at 
least 50%, more preferably at least 75% of the CLA residues are residues 
in which 1 double bond is in the cis configuration and 1 double bond is in 
the trans configuration. It is particularly preferred that the CLA 
residues comprise at least 40% especially at least 50% and most preferably 
at least 60% of 9-cis, 11-trans octadecadienoic acid isomer residues. 
Triglycerides having CLA esterified therein can suitably be prepared by 
converting a mixture of free fatty acids containing linoleic acid into an 
acid mixture comprising CLA acids e.g. as described in Cancer Research, 
51, (1991), 6118-6124 and then incorporating the CLA acids into 
triglycerides e.g. as described in GB 1,577,933. 
The fat of the fat spread preferably consists of a CLA-rich triglyceride 
mixture combined with commonly used oils or fats or fat-components. The 
CLA-rich triglyceride mixture, e.g. prepared as described above, 
preferably comprises 10-50%, especially 20-40% of CLA residues in the 
triglycerides, calculated on the weight of the total amount of the fatty 
acid residues. The other oils or fats preferably comprise liquid oil, i.e. 
oil that contains no solid fat at 200.degree. C., preferably at 15.degree. 
C. Examples of such liquid oils are sunflower oil, safflower oil, low 
erucic acid rapeseed oil, linseed oil, soybean oil, cottonseed oil, high 
oleic acid residues containing varieties of such oils, groundnut oil, 
olive oil, and mixtures of two or more thereof. Unhardened marine oil, 
e.g. fish oil from sardines or pilchard can also be incorporated. It will 
further often be appropriate, e.g. when making a fat-continuous spread, to 
incorporate a structuring fat. In an other embodiment, it is preferred 
that the fat composition comprises at least 30%, and more preferred at 
least 45% of polyunsaturated. As such for example an interesterified 
mixture of a lauric fat, e.g. palmkernel stearin and a fat rich in 
saturated fatty acid of 16 carbon atoms chain length or longer, e.g. palm 
oil stearin. Structuring fats, in particular also structuring fats for 
spreads designed to have low contents of saturated and trans-unsaturated 
fatty acid residues other than CLA, are well known in the art. Such 
structuring fat is preferably prepared from vegetable fat. Animal fats 
such as beeffat, e.g. tallow and milkfat are preferably not incorporated 
in the product. 
The CLA rich triglyceride mixture may be designed such that it behaves 
physically like a liquid oil, e.g. by esterifying CLA to partial 
glycerides, e.g. diglycerides, the fatty acids of which are largely 
unsaturated, e.g. a partial glyceride mixture prepared from low erucic 
acid rapeseed oil. Alternatively, the CLA rich triglyceride mixture can be 
made to become a structuring fat, e.g. by esterifying CLA to a partial 
glyceride mixture of palm oil stearin. Whatever form of CLA rich 
triglyceride mixture is employed, the overall fat composition can be 
adapted to obtain a fat suitable for making a spread by adjusting the 
types and amounts of (other) liquid oil and/or structuring fat used in the 
composition to make up the total fat to be incorporated in the product. 
Methods to do so are well known in the art. 
Preferably the composition of the fat is chosen such that it comprises at 
least 20%, more preferably at least 30%, especially at least 40% of 
all-cis polyunsaturated fatty acid residues (PUFA) e.g. residues of 
linoleic acid, .alpha.- and/or .gamma. linolenic acid, EPA and/or DHA. 
The spread may be a water continuous spread. In such products it may not be 
necessary to include any structuring fat, although generally the presence 
of some structuring fat is usually beneficial to obtain optimal product 
quality. 
Preferably the product is a fat continuous spread, however. Particularly 
preferred fat continuous spreads are margarines (80-83% fat), so-called 
halvarines (35-45% fat) and spreads with a fat content in between these 
two product types. 
The composition of the fat is preferably chosen such that the solid fat 
content as a function of temperature and measured by NMR as is well known 
in the art, using stabilisation of at least 10 minutes at a temperature of 
60.degree. C. or higher, 60 minutes at 0.degree. C. and 30 minutes at 
measuring temperature, is as follows: 
N.sub.10 : 7-55, more preferably 7.5-50 
N.sub.20 : 4-33, more preferably 4.5-30 
N.sub.30 : 0-13, more preferably 0.5-10 
N.sub.35 : max 5, more preferably 0-4 
It is particularly preferred for the N-values to be: 
N.sub.10 : 8-25 
N.sub.20 : 4.5-12 
N.sub.30 : 0.5-6 
N.sub.35 : 0-3 
The fat continuous spread need not contain an aqueous phase. It can for 
example be a shortening suitable for cooking and baking. Preferably 
however the spread comprises 85-20% fat phase and 15-80% aqueous phase, 
more preferably 83-35% fat phase and 17-65% aqueous phase. 
The fat phase of the product may comprise apart from triglyceride fat, 
small amounts of other ingredients e.g. emulsifier, colourant, flavour, 
vitamins e.g. vitamin E, etc. The aqueous phase if any, may comprise apart 
from water, milk constituents e.g. milk protein powder, food acid, salt, 
flavour, preservatives, gelling and/or thickening agents etc. 
The invention also encompasses a preferred process for preparing the 
present edible spread wherein: 
free CLA is incorporated into triglycerides to obtain a CLA rich 
triglyceride mixture 
the CLA rich triglyceride mixture is combined with triglyceride fat to 
obtain a fat blend 
a fat phase composition is prepared that includes as fat the fat blend 
the fat phase composition is subjected to processing, optionally in 
combination with an aqueous phase composition, to obtain the spread. 
Throughout this specification, the terms oils and fats are used 
interchangeably. Percentages, parts and proportions are by weight unless 
indicated otherwise. Amounts of fatty acids residues of a fat are 
expressed with respect to the total fatty acid residues of the fat. The 
expressions "comprises" and "comprising" encompass "consists of" and 
"consisting of". 
N-values can be measured as described in Fette, Seifen Austrichmittel, 80, 
(1978), 180-186. The fatty acid composition of fats can be measured by GLC 
e.g. as described in EP 78568. The composition of the isomers of CLA and 
the total amount of CLA residues, can be determined by FAME GLC e.g. as 
described in J. Agri. Food Chem. 37, (1989),75-81. 
Spreads can be produced e.g. as described in "Margarine" by Anderson and 
Williams; Pergamon Press (1965).

EXAMPLE I 
A CLA rich triglyceride mixture was prepared as follows: A commercially 
available mixture of free fatty acids having a linoleic acid content of 
95.3% was added to a solution of NaOH in ethylene glycol. The mixture was 
heated to 18.degree. C. under an inert atmosphere for 2 hours. The 
reaction mixture was cooled and the pH adjusted to 4 with HCl. The mixture 
was extracted with hexane. The extract was washed with an NaCl solution 
and dried over NaSO4. The hexane was removed by evaporation. The product 
contained 90% CLA and consisted mainly of 9 cis, 11 trans and 10 trans, 12 
cis CLA isomers in approximately equal amounts. 3 Parts of this acid 
mixture was mixed with 10 parts palm oil. Immobilised Mucor miehei lipase 
was added and the mixture was gently stirred for 48 hours while it was 
kept at 45.degree. C. Then the lipase was removed by filtration and the 
free fatty acid was removed by washing with aqueous methanol. The CLA rich 
triglyceride mixture thus obtained was refined using conventional methods. 
Its free fatty acid content was less than 0.1%. The fatty acid residue 
composition of the triglycerides was: 
______________________________________ 
0.3% C12 
0.8% C14 
32.6% C16 
3.6% C18 
32.9% C18:1c 
12.5% C18:2cc (linoleic acid) 
7.6% 9 cis, 11 trans-CLA isomer 
8.1% 10 trans, 12 cis-CLA isomer 
0.6% other CLA isomers 
0.2% C20 
0.1% C20:1c 
0.7% other fatty acids 
Trans other than CLA: 
&lt;1% 
SAFA 38% 
CLA 16.3% 
PUFA 12.5% 
______________________________________ 
8 Parts of this mixture is blended with 79 parts refined sunflower oil and 
13 parts of a refined interesterified mixture of 50 parts fully hardened 
palm oil and 50 parts fully hardened palm kernel oil. 
The resulting fat blend, has the following fatty acid residue composition: 
______________________________________ 
0.7% C8 + C10 
3.4% C12 
1.2% C14 
10.2% C16 
8.4% C18 
18.0% C18:1c 
55.1% C18:2cc (linoleic acid) 
0.61% 9 cis, 11 trans CLA isomer 
0.65% 10 trans, 12 cis CLA isomer 
0.05% other CLA isomers 
0.3% C20 
1.4% other fatty acids 
Trans other than CLA 
&lt;1% 
SAFA 25% 
CLA 1.3% 
PUFA 55% 
______________________________________ 
To 70 parts of this fatblend, 0.1 part soybean lecithin, 0.1 part 
monoglyceride and a small amount of .beta.-carotene solution are added. 
To 29 parts water, 0.5 part whey protein powder, 0.1 part salt, a small 
amount of flavour, and citric acid to obtain a pH of 4.5 are added. 
70 parts of the fat phase composition and 30 parts of the aqueous phase 
composition are mixed and kept at a temperature of 55.degree. C. The 
mixture is passed through a Votator line with 2 scraped surface heat 
exchangers (A-units) and 1 stirred crystallizer (C-unit) operating at 100 
rpm. The product leaving the C-unit has a temperature of 11.degree. C. It 
is filled into tubs and stored at 5.degree. C. A good fat continuous 
spread is obtained. It contains 1.3% CLA residues calculated on the fatty 
residues of the product which corresponds to 0.87% CLA residues on the 
total product. 
EXAMPLE II 
Male F1B hybrid Syrian (golden) hamsters were fed semipurified diets 
containing 0.01 w/w cholesterol and 30 percent of energy (en %) as fat for 
eight weeks. The dietary fat in diet `A` contained 12.2 en % saturated 
fat, 10.8 en % monounsaturated fat, and 7.0 en % polyunsaturated fat 
(PUFA; mainly linoleic acid (LA)). In diet `B` 1.5 en % of the linoleic 
acid was replaced by conjugated linoleic acid (CLA) and incorporated into 
a triglyceride according to the procedure as described in Example I. At 
the end of the dietary period blood samples were collected for analysis of 
total, HDL and LDL cholesterol. In Table 1, the data on cholesterol 
(mmol/L) in blood (means and number of animals/analyses (n)) are provided. 
TABLE 1 
______________________________________ 
A B 
Parameter LA CLA n* 
______________________________________ 
Total cholesterol 
3.67 3.45 30 
HDL-cholesterol 
1.55 1.43 15 
LDL-cholesterol 
1.08 0.83 15 
______________________________________ 
*Each figure is the mean obtained from 30 different animals; in case n = 
15, samples have been pooled from 2 animals on the same diet. 
On average in the CLA-group (`B`) total cholesterol was 5.9% lower than in 
the control group (`A`). LDL-cholesterol was 22.9% lower and 
HDL-cholesterol was 7.8% lower. Overall it can be concluded that CLA 
incorporated into a triglyceride positively contributes to the bloodlipids 
profile.