Crystallizers: The crystalclear answer to trans fat-free
margarine production
Palsgaard has examined how crystallizers can step in to fill the production
performance gap left by slowly crystallizing, trans fatty acid-free margarines.
By Anders Mølbak Jensen, Product & Application Manager, Lipid & Fine Foods Palsgaard A/S.
PUBLIC ENEMY:
TRANS FATS
For the origins of the fight against
partially hydrogenated fats and the
trans fatty acids they produce, we
have to go back to the early nineties. That’s when a famed Harvard Medical School paper was
released, reporting the results of
a long-term epidemiological study
that tracked, among other factors,
the dietary habits of almost 80,000
female nurses1. The study was
considered by many to be a landmark in the fight against coronary
disease.
The Harvard research team, led
by Dr. Walter Willett, arrived at a
number of eye-opening conclusions, one of which is that trans
fats present a significant health
risk, with higher risks of cardiovascular disease already registered at
daily trans fatty acid intake levels
of just 5 to 6 grams.
Further research has pointed to an
ability of saturated fat and trans
fats to raise the level of Low Density Lipoprotein Cholesterol (LDL)
in the blood. Excess LDL particles
are deposited in the arteries, lead-
ing to hardening of the arteries
and heart disease over time2. Simultaneously, trans fats appear to
decrease High Density Lipoprotein
Cholesterol (HDL), further increasing the risk of heart disease. Other
studies have indicated that a high
intake of saturated fats and trans
fats promotes insulin resistance,
too, threatening consumers with
Type 2 diabetes.
INSTANT EFFECT
ON THE INDUSTRY
The impact of the Harvard study,
and follow-up research, on the food
1
industry was powerful and, at least
in Europe, instantaneous. Danish
consumers, for example, reacted
quickly, slashing their purchases of
margarine by around 15% almost
overnight, and butter grabbed new
market share. Legislators moved
almost as quickly, and since 2004
in Denmark, for example, oils and
fats used in food products have
been permitted a maximum of 2%
trans fat content (excepting oils
and fats of animal origin).
For European margarine manufacturers, the message was clear:
something needed to be done to
reduce their recipes’ content of hydrogenated fats and restore consumer confidence.
The US, on the other hand, has
been somewhat slower to react,
though it introduced mandatory labelling for trans fats in 2006.
Most recently however, in June
2015, the FDA has finalised a determination that trans fats are not
generally recognized as safe, and
set a three-year time limit for their
removal from all processed foods.
Of course, the ban needs to be
seen in the light of an 85% reduction that has been gradually
achieved by the industry over the
past 10 years, mainly due to the
mandatory labelling, but the writing
is clearly on the wall for US manufacturers: It’s simply not enough.
So, while the industry is pushing
to have very low amounts of trans
fats allowable in, for example, the
sprinkles on cupcakes or cookies, manufacturer focus is now on
tuning recipes to deliver unaltered
product quality in an uncompromising new, trans fat-free landscape.
LIFE WITHOUT TRANS FATS
No trans fats on your new ingredients list? Congratulations: life as a
production manager at a margarine manufacturer is about to get
much more interesting.
Partially hydrogenated oils have
long enabled margarine to step up
to the plate, forming more stable
2
products and supporting mouthfeel to deliver an eating experience
not far from that of butter. And their
positive effect on shelf-life is well
documented, too.
Without trans fats, it’s much more
difficult to consistently produce
high-quality margarine. In fact, every part of the production process
becomes more sensitive to a variety of factors that were comfortably, even transparently, handled
by partially hydrogenated oils in
the past.
HIGHER MELTING POINT
One such factor is the higher melting point of other fat types. For optimum flavour release, it’s best to
use fats that melt at approximately mouth temperature: around 35
o
C (95 oF). In the old world, trans
fats fitted the bill perfectly. In the
new one, the only economically
feasible, readily available fat type
is palm oil, fractions of palm oil, or
interestified fat types.
That said, the melting point of palm
oil is still a little higher than that of
trans fats, and it lacks comparable
functionality. Not only that, but in
the US, and for reasons that may
be difficult to pin down, the use of
‘tropical’ oils has long been given
the cold shoulder. So palm oil isn’t
a viable option in that part of the
world.
The melting point of a fat isn’t just
important for the consumer’s eating experience, it also affects the
ability of manufacturers to work
with the fat during the production
process. In a trans fat-free world,
you get a mixture of high melting
point fractions and liquid oil, giving
a higher melting point and a tendency toward softer products.
Perhaps the most important phenomenon, however, for margarine
manufacturers to think about is
the slower crystallization speed
of trans fat alternatives – and this
brings us to the particular focus of
this paper.
FACT BOX: The effect of
trans fatty acid reduction
•
Higher melting point
•
Slow crystallization of
the fat types
•
Easier to overwork the
fat product
•
Post crystallization
•
Change structure over
time
•
Storage: more sensitive
to temperature variations
THE EFFECTS OF
SLOWER CRYSTALLIZATION
A lot has been done to address
slow crystallization issues, but
generally, manufacturers are simply unable to produce as much
margarine from the same production lines as before. Process
parameters, including machine
settings, need to be adjusted to
cope with the slower crystallization, and most often, investments
in new tube chillers are demanded
or, for example, the combination
two machines where only one was
needed before. Whichever route
was chosen, final product quality
just isn’t the same as that of trans
fat-containing recipes.
Without trans fats, for example,
margarine begins to crystallize
on the tube chiller shaft, reducing
production capacity by perhaps
20% from morning to afternoon, as
there is gradually less volume to
work with. Flushing the tube with
heat to restore capacity is one way
to fix the problem, but has its own
set of drawbacks and can’t be recommended.
Lower production capacity is one
effect of crystallization. Another
is that, due to the slower crystallization speed of alternative fats,
crystallization continues to develop for longer than the usual 24
or so hours during pre-storage,
changing its structure over an ex-
tended period of time. So you’re
likely to end up with a more brittle
product than you’re used to. Storage, therefore, has a much greater
effect on the final product – and
storage temperature variations
introduce further sensitivity to recrystallization.
Pre-storage, therefore, seldom the
focus of a margarine production
process in the good old trans fat
days, has suddenly taken on new
significance for the final product’s
quality. Now manufacturers need
to focus on pre-storage during
the first 5 to 7 days following production, making this aspect part
of the overall production process.
For example, an attempt might be
made to to reduce brittleness and
ensure consistency by varying
pre-storage temperatures from, for
example, 21 degrees for the first 5
days then reducing to 16 degrees
thereafter. One implication for
many manufacturers is the need to
invest in pre-storage facilities that
can enable the required temperature control.
Slower crystallization, therefore,
is a manufacturer’s nightmare, imposing both immediate limitations
on total production capacity and
gradually reduced capacity during
production days due to crystallization buildup on chiller shafts.
Non-hydrogenated products will
have a slower crystallization
speed, and interestified products
have a tendency to become overworked and very soft.
likely to be carefully concocted
combinations of crystallizers and
emulsifiers.
Crystallizers, in particular, can do
much to ease the production process. And we’ll take a thorough
look at exactly how shortly. That
said, crystallizers will not have
significant influence on the longer-term storage phase, during
which polymorph structure will
make for a firmer margarine over
time, an aspect that manufacturers
will still need to give special attention to in their trans fat-free strategies.
EXPLORING TRANS
FAT-FREE PRODUCTION
STRATEGIES
To get to the bottom of the case for
these ingredients as the toolbox of
choice for food manufacturers facing the trans fat ban, we first needed to gain a better understanding
of crystallization processes in margarine oils and fats. We were particularly keen to find out how various process parameters affected
the speed and nature of crystallization. Equipped with this knowledge, we would then be able to
properly examine the role played
by emulsifiers in relation to crystallization, and to make recommendations to margarine manufacturers based on our findings. And we
set the bar high: our tests would
be conducted with one of the most
difficult beasts in the business: puff
pastry margarine.
WHAT AFFECTS CRYSTALLIZATION IN MARGARINE AND
SHORTENING?
When chilling begins in the margarine production process, there are,
at first, no crystals. Then the first
crystals appear, creating a ‘seat’
for more to build upon, finally arriving at a much firmer mass. This
firmness needs to be broken down
somewhat, restoring plasticity.
To tackle this problem, we used
one of our pilot plants to start the
seating earlier in the process, allowing more time in the machine
to reduce post-crystallization time.
Longer time in the equipment,
however, means greater effect
from the pin machine and the following tube chillers, resulting in a
quite different product.
In our trials, we compared hydrogenated, interesterified fat, and
unhydrogenated fat in puff pastry margarine. Hydrogenated fat,
as might be expected, performed
best, crystallizing quickly. Far
slower to crystallize, unhydrogenated fats such as palm oil clearly
perform worst. In fact, both before
and after the pin machine it was
hopelessly overworked, and would
be impossible to pack or, for that
matter, to eat. The interesterified
fat medium crystallized well, but
again was all too easy to overwork.
IN STEP CRYSTALLIZERS
AND EMULSIFIERS
With widespread attention on the
ill effects of trans fats, US food
manufacturers and their European
counterparts now need to come up
with trans fat-free recipes that give
margarine’s batch-by-batch quality
the best possible chance of success.
According to Palsgaard’s application center research into the area,
and our lengthy experience in the
first-to-move European market,
that particular ‘something’ is most
Liquid margarine with
Palsgaard crystallizer
Liquid margarine without
Palsgaard crystallizer
3
Tribehenate Mp 142oF
Crystallizer Mp 142oF
2500
At Palsgaard, we’ve determined
the most effective strategy is to
use crystallizers as a trans fat-free
‘remedy’.
2000
These can be, for example:
• High in behenic acid (C22) and
steric acid (C18)
• High in steric acid (C18) and
palmitic acid (C16)
• Very high in steric acid (C18)
• Mixture of behenic acid (C22),
steric acid (C18) and palmitic
acid (C16)
The melting points of various fatty
acids, triglycerides and crystallizers can be seen in Table 1. A key
aim is to determine a crystallizer
whose melting point makes it easy
to use in production. This can be
achieved with steric acid (18),
combined with behneic acids.
Tribehenic and monobehenics
have the most extreme melting
points for crystallizers. At 180 oF
(82.2 oC), they cannot be handled in
a normal production environment.
If a pipe were to become blocked,
for example, things would become
very problematic. Despite this, and
in the name of thorough research,
we did attempt to use this acid in
various recipes, but achieved the
same or better results with other
products. Other triglyceride compositions, on the other hand, with
behenic acids can produce a lower
melting point, making them easier
to handle in production.
1500
100
Reference
500
100
340
820
580
1060
0
Figure 1:
Crystallizing effect of crystallizer compared with tribehenate
Any of these acids can easily purchased, but constructing these
triglycerides – using high melting
point behenic acids yet ending up
with something that has a significantly lower melting point – is no
walk in the park. Locating the behenic acids in the right place on
the chain requires more than a
little expertise! With these acid in
the right positions, however, the
melting point can be brought down
to as little as 66 degrees C instead
of, for example, 82.
CRYSTALLIZING EFFECT OF
CRYSTALLIZER COMPARED
WITH TRIBEHENATE
Using Tribehenate Mp, with its 82
o
C (180 oF) melting point, speeds
up crystallization greatly in com-
parison with our reference (40%
palm oil, 40% palm stearin and
20% liquid soya oil without crystallizer), as can be seen in Figure 1.
The Mp crystallizer we tested almost matches Tribehenate Mp’s
speed, but with a lower melting
point of 61 oC (142 oF). Both solutions far outstrip the performance
of the reference. The tests also
revealed that using crystallizers
forms more beta prime crystals,
which have a better absorbing effect than other crystal types. The
tests also revealed that using crystallizers forms more beta prime
crystals, which have a better absorbing effect than other crystal
types.
Table 1:
Melting points of fatty acids, triglycerides and crystallizers
4
η in Cp
CRYSTALLIZERS: THE
SOLUTION OF CHOICE
3000
TRIVIAL NAME
MELTING POINT
TRIVIAL NAME
MELTING POINT
C12:0
Lauric acid
44.4°C (112°F)
Trilaurin
46.1°C (115°F)
C14:0
Myristic acid
54.4°C (130°F)
Trimyristin
55°C (131°F)
C16:0
Palmitic acids
62.7°C (145°F)
Tripalmetin
65°C (149°F)
C18:0
Stearic acids
69.4°C (157°F)
Tristearin
72.2°C (162°F)
C22:0
Bebenic acids
80°C (176°F)
Tribehenic
82.2°C (180°F)
C18:1 n-9 cis
Oleic acid
16.1°C (61°F)
Crystallizer : C22 –C18
61.1°C (142°F)
C18,1 trans
Elaidic acid
43.8°C (111°F)
Crystallizer : C16 –C18
57.2°C (135°F)
C18:2 n-6 cis
Linoleic acid
-6.6°C (20°F)
Crystallizer : C16 –C18-C22
58.8°C (138°F)
C18:3 n-3 cis
Linolenic acid
-12.7°C (9°F)
Crystallizer : C18
72.2°C (162°F)
TRIAL 3
TRIAL 4
TRIAL 5
TRIAL 8
TRIAL 9
TRIAL 10
Palsgaard® 6111
1.70%
1.70%
1.70%
0.00%
0.00%
0.00%
Palm stearin
40.00%
42.00%
45.00%
40.00%
42.00%
45.00%
RBD. palm oil
40.00%
42.00%
45.00%
40.00%
42.00%
45.00%
Liquid soya oil 6°C
18.30%
14.30%
8.30%
20.00%
16.00%
10.00%
100%
100%
100%
100%
100%
100%
Melting point:
56.20%
56.90%
56.20%
51.70%
50.80%
52.80%
Avr. SFC % 10°C/50°F
61.90%
63.00%
67.20%
52.00%
55.40%
59.80%
Avr. SFC % 20°C/68°F
50.00%
51.70%
54.80%
40.20%
42.00%
43.90%
Avr. SFC % 30°C/86°F
31.70%
32.20%
34.20%
21.00%
22.40%
24.80%
Avr. SFC % 40°C/104°F
21.00%
21.80%
22.70%
12.40%
13.00%
13.90%
Oil blend:
Table 2:
SFC values in puff pastry margarine blends with and without crystallizer
SFC VALUES WITH AND
WITHOUT CRYSTALLIZER
Moving on with our exploration, we
examined more or less the same
puff pastry margarine recipe as in
the previous trials, this time adding
1.7 grams of crystallizer. We were
keen to determine the Solid Fat
Content (SFC) values that resulted
from this addition. These are depicted in Table 2.
The trials demonstrated a somewhat surprising result: While 1.7%
crystallizer is not a large portion
of the recipe, its effect on crystallization was strong, quickly getting
the seating in place upon which to
build further crystals. Judging by
the SFC values in Table 2, crystallizers have a strong effect on fat
crystallization because they activate some of the fats to crystallize
more quickly than would otherwise
be the case. With other test methods, 24 to 48 hours at 0 oC (142
o
F) would have been required to do
this.
pilot plant’s bar pressure indicates
that crystallization is occurring.
When producing at low capacity
(40%), the fat has time to crystallize by itself. But at higher capacity (above 70%), low bar pressure
shows the fat is more liquid and
crystallization is less effective.
At low capacity, fast-crystallizing
fat types can produce crystallization, but it requires crystallizers to
be added to increase contact and
result in sufficient crystallization
both at higher and lower capacities.
As a general conclusion, it seems
that the more crystallizers you add,
the higher the bar pressure and
therefore the better you are able
to maintain or increase capacity.
Without adding crystallizers, you
would need to reduce capacity, allowing the blend to remain in the
tube chillers for longer. So, while
adding crystallizers will increase
recipe costs, there’s a worthwhile
trade-off in better utilisation of production equipment.
Still in our experimental corner,
we decided to look more closely
at the effect of different crystallizer dosages on production capacity, moving from zero to 0.5%, 1%,
1.5% and, finally, right up to 2%. To
make things more interesting, we
simultaneously tested the effect of
two different rotation speeds: 400
and 800 RPM.
Figure 2:
The effect of crystallizer doses on production capacity
10
9
10
8
CRYSTALLIZERS AND PRODUCTION CAPACITY
Next up, we took a closer look at
the effect of crystallizers on production capacity. Figure 2 shows
the results of testing a similar puff
pastry margarine recipe to that
used in our other trials.
We tested two production capacity
levels, each with and without crystallizers added. In Figure 2, the
7
8.1
6
0.0% crystallizer 40%
bar 5
1.5% crystallizer 40%
4
0.0% crystallizer 70%
4.4
3
10
1.5% crystallizer 70%
29
10
18
7
0
0.5
8.1
6
0.0% crystallizer 40%
bar 5
1.5% crystallizer 40%
4
3
0.0% crystallizer 70%
4.4
1.5% crystallizer 70%
2
1
0
0.5
5
3.2
In Figure 5, rotation speed strongly affects expansion results, performing best at around 11 RPM.
Introducing crystallizers smooths
out the effects of rotation speeds,
enabling a good expansion result
not only with different process
parameters but also on different
machines – expansion simply becomes less sensitive to process
parameter variations. There is, of
course, production machinery that
6
3.2
3
2.8
2.6
2.5
2.8
2.6
2.6
2.4
2.4
2.4
2.4
2.6
2.6
2.4
2.4
2.8
2.8
2.6
2.5
2.4
2
1.5
1
0.5
0
0.0% Crystallizer
0.5% Crystallizer
1.0% Crystallizer
1.5% Crystallizer
2.0% Crystallizer
Figure 3:
The effect of crystallizer doses at 400 RPM
Figure 4:
The effect of crystallizer doses at 800 RPM
400 rpm in all tube chillers
600 rpm in all tube chillers
800 rpm in all tube chillers
12
11.2
10
11
9.6
8
Exspansion (x)
Normally, rotation speed isn’t a parameter most production staff can
work with. Often, that’s because
most production machinery has a
fixed speed – or enables switching
only between one or two levels.
Now however, in a trans fat-free
landscape, the ability to adjust
rotation speed in combination
with various dosages of crystallizers has become a key factor for
achieving the right result.
Tube chiller 3
Tube chiller 2
3.5
CRYSTALLIZERS AND
PRODUCTION CAPACITY
Margarine produced for incorporation into puff pastry is very thin
when first made, expanding in the
oven to arrive at the mouth-feel
loved by consumers all over the
world. Seen from a puff pastry expansion point of view, trials with
Palsgaard’s crystallizers produce
a very stable margarine. No matter
how hard we work the product, it
still performs well in this vital regard. But we were curious to learn
what might happen if we were to
conduct a baking test on the final
product itself. So we measured the
effect on ten such pastries of increasing crystallizer dosages from
zero to 2%, switching between
three different rotation speeds.
Pin machine 1
Tube chiller 1
Amp
In Figures 3 and 4, the coloured
bars represent the four tube
chillers in our pilot lab production
setup. It came as no surprise, of
course, that the viscosity needed
for margarine required more energy toward the end of the production line. We also confirmed that
applying crystallizers does indeed
increase viscosity by the end of the
process, but the difference they
make is nothing extraordinary.
9.9
9.8
9.3
9.2
9.3
10.8
10.4
10.8
10.7
10.7
9.7
8.6
6
4
2
0
0.0% crystallizer
0.5% crystallizer
1.0% crystallizer
1,5% crystallizer
Figure 5:
The effect of different process parameters on puff pastry expansion
2,00% crystallizer
can arrive at comparable results
without any addition of crystallizers, but few manufacturers have
invested in the up-to-date equipment that can do it.
ARE CRYSTALLIZERS
AWAYS NECESSARY?
Let’s stop for a moment and ask
an important question: Have we all
too narrowly pursued crystallizers
as the only feasible solution to the
problem of slower crystallization?
Are they, in fact, always necessary?
The answer is ‘no’. It is possible
to create recipes that perform just
as well as, or at least comparably to the performance of a trans
fat-containing formulation. Cake
margarines, for example, that use
fast-crystallizing fat types such as
palm oil or coconut oil fat, have
nothing to be gained by adding
crystallizers. But with cheaper fat
types, small amounts of crystallizers can make a significant difference.
There is, however, no way to avoid
spending some amount of additional funds to cope with a trans
fat-free world – and for most, the
costs will be high. Manufacturers
will need to take a look at their
equipment line-up. Most likely,
older machinery won’t be enough
to maintain current capacity and
product quality on the new, trans
fat-free playing field – at least, not
without applying crystallizer dosages as high as 2%.
Upgrading brings new and better
technologies with it – enabling,
for example, the use of CO2 as a
more efficient and effective cooling medium. But even after an upgrade to more modern equipment,
manufacturers should still expect
to incorporate from 0.5 to 1% crystallizer content in their recipes.
A TOUGH JOURNEY
For European manufacturers, who
have been battling the effects of
low or no trans fat recipes for quite
some years now, it’s been a tough
journey. The only comfort, perhaps, was the fact that everyone
was in the same boat – product
quality decreased across the entire industry and everyone needed
to come up with their own answer
to the problems. In the US, things
are about to heat up – but there’s
much to be learned from the journey already embarked upon by
their European competitors.
In a nutshell, to cope with a trans
free future, production managers
need to realize that the days of
pouring in ingredients, setting the
machines and retreating to the
comfort of the control room are
most likely over. Instead, even a
minor fluctuation in production requires active – and proactive – efforts. And most affected are those
whose job it is to produce puff pastry.
Manufacturers have a variety of
other avenues to turn to for advice,
too, including concentrated efforts
being made by oil refineries (developing new oils and fat types),
universities, in-house R&D centers
and machinery/storage suppliers.
The sooner the industry faces up to
the issues discussed in this article,
the better. Failure to move quickly
enough is likely to result in a rollercoaster ride through reduced capacity, zig-zagging product quality
and costly re-runs. The sooner the
effort is made, therefore, the lower
the overall cost of the necessary
transition to trans free products –
and the smoother the journey for
both manufacturers and their customers.
1
WE’RE HERE TO HELP
Margarine manufacturers need to
develop new production strategies,
understanding the new realities
described above, experimenting
with crystallizers and emulsifiers
in their recipes, and preparing for
significant capital investments in
equipment.
American Journal of Epidemiology.
2005 Apr 1;161(7):672-9.
Dietary fat intake and risk of coronary
heart disease in women: 20 years of
follow-up of the nurses’ health study.
2.
Oh K1, Hu FB, Manson JE, Stampfer
MJ, Willett WC.
Palsgaard is here to help its customers work their way through
the hurdles, helping to arrive at a
roadmap for process, recipe and
equipment adaptations. We have
all the equipment needed to play
with every production parameter,
taking samples at many different
points and conducting trials that
simply wouldn’t be feasible in a live
production environment.
ABOUT THE AUTHOR
Anders Mølbak Jensen, is Product & Application Manager, Lipid & Fine Foods Palsgaard
A/S. He can be reached at am@palsgaard.
dk or +45 7682 7682. Before joining the company 16 years ago, he held various roles as a
laboratory, quality control and R&D manager
at a large margarine producer for 10 years.
He holds an M.Sc in food science and technology from the University of Copenhagen
and a Bachelor of Commerce, IT. His email
is [email protected]. Get more info at www.
palsgaard.com.
7