BEVERAGE COMPRISING SOY PROTEIN AND CITRUS FIBERS
Field of the Invention
The present invention relates to the field of non-fermented soy-based beverages.
Background of the invention
Consumers have become more knowledgeable about protein and its role in a healthy
diet. This new understanding has had a profound effect, stimulating consumer interest
and demand for healthier beverages that are fortified with protein. Because
beverages are a convenient way to incorporate protein into the diet, manufacturers
continue to formulate new products in an effort to make protein more accessible to a
wider group of consumers.
The two most popular beverage proteins are whey and soy, and their various isolate
derivatives. According to the U.S. Food and Drug Administration, the consumption of
food products rich in soy protein can reduce cholesterol, enhance athletic
performance, and even aid in the battle against diabetes. In addition, interest for milk
replacement by soy protein has increased in view of, on the one hand, issues in
relation to over-sensitivity and/or intolerance towards milk constituents experienced by
growing numbers of consumers and, on the other hand, elevated milk protein prices
and supply issues that some manufacturers are experiencing relative to this
commodity. Soy proteins have been proposed to replace milk proteins, either partially
or totally, depending on the system, and dairy-like products have been developed
based entirely on soy protein.
In view of soy protein's documented health benefits it is desirable to incorporate
substantial quantities of soy protein in beverages.
Soy protein-containing beverages typically have, in their crude form, often more or
less off-flavours (taste, but in particular aroma or volatiles) which relate to the origin of
the material, and in particular such is the case for soy protein from a less than ideal
quality source. Typical examples of such disturbing aromas or volatiles are often
described (by panels or trained flavourists) as "soy" or "cereal". For this reason, most
soy drinks are heavily flavoured, e.g. by fruit flavours, vanilla flavours, or chocolate
flavours, to mask such. Also, fruit juices and/or fruit pulps or concentrates are used for
such, by blending them with soy protein-containing beverages, in which case one
aims to overpower the soy or cereal aromas and flavours by fruit flavours. Alternative
solutions to this which have also been proposed for improving the profile of aromas or
volatiles is subjecting the soy material to fermentation with e.g. lactic acid bacteria, as
is disclosed e.g. in WO 2009/065722, WO 2009/065723 and WO 2009/065724. Such
may provide an adequate solution, but it will e.g. increase processing complexity and
cost. For some purposes it can be desired to be able to provide a soy protein
containing beverage which is not fermented, and still has an improved aroma / volatile
profile, especially w.r.t. a reduced level of "soy" and/or "cereal" notes.
It is generally accepted that for an aqueous beverage containing soy protein (e.g. in
an amount of protein similar to dairy-milk), that in order for an acceptable mouthfeel or
texture, a thickening agent needs to be included. There are currently commercial soybased
beverages on the market in Europe, which comprise gellan for that purpose.
Thickening agents like gellan or carrageenan are also employed in other drinks than
soy protein containing beverages, e.g. to prevent sedimentation, e.g. in cocoacontaining
beverages, or to improve the mouthfeel and/or texture, and another
thickening agent also used for such is e.g. CMC (carboxymethyl cellulose). The
amounts employed are usually small, so as to not unduly thicken the product.
WO 2009/065725 discloses a fermented beverage comprising soy protein and
insoluble cellulosic fibres. The use of such cellulosic fibres in such beverages is
reported to provide a very pleasant creamy mouthfeel and significantly improves
emulsion stability, typically reflected by a reduced rate of syneresis.
WO 2005/074713 discloses products comprising insoluble citrus fibres. Said
compositions are preferably not beverages.
WO 2007/003391 discloses compositions comprising citrus fibres and a hydrophobic
vitamin like one of the vitamins A, D, E, or K, and it discloses a process to prepare
such compositions.
US patent application US 2003/0059514 discloses compositions comprising soy
protein, wherein the protein is present in particles having a mean particle size
distribution of 0.1 to 10 microns. Furthermore, a process to obtain such composition is
disclosed.
Summary of the Invention
It is an object of the present invention to provide a ready-to-drink, packaged nonfermented,
soy protein-containing beverage comprising 1-8% soy protein, which
beverage is modified such that it has a reduced level of soy and/or cereal off-flavours
or aromas, compared to a beverage not modified.
Preferably the beverage is suitable as a base product for preparing other soy protein
containing products with, which means that the beverage preferably should have a pH
of more than 5.5 and less than 8. This also means that the product should preferably
be a non-fermented soy protein beverage, as such may limit the application as a
neutral base product. Also, the beverage should have a viscosity or mouthfeel not too
much different from conventional products (i.e. flavour or aroma improvements should
not be at the expense of substantially modified viscosities or mouthfeel).
It has now been found that the above may be achieved, at least in part, by a ready-todrink,
packaged non-fermented soy-based beverage having a water content of at
least 80 wt.%, a soy protein content of 1.0-8.0 wt.%, a fat content of 0 to 5 wt.%, said
beverage further comprising from 0.01 to 0.4 wt.% of insoluble cellulosic citrus fibres,
said beverage having a viscosity of below 0.5 Pas at a shear rate between 2 and 100
s , when measured at 5°C.
Also, the above objectives may be achieved at least in part by a ready-to-drink,
packaged soy-based beverage having a water content of at least 80 wt.%, a soy
protein content of 1.0-8.0 wt.%, a fat content of 0 to 5 wt.%, said beverage further
comprising from 0.01 to 0.4 wt.% of insoluble cellulosic citrus fibres, said soy-based
beverage having a pH in the range of more than 5.5 and less than 8, and said
beverage having a viscosity of below 0.5 Pas at a shear rate between 2 and 100 s ,
when measured at 5°C.
Detailed description of the invention
For the beverages according to the present invention, it was surprisingly found that
insoluble cellulosic citrus fibres can improve flavour, in particular aroma in nonfermented
soy-protein containing beverages and in soy-protein containing beverages
having a pH in the range of more than 5.5 and less than 8. This is surprising as so far
citrus fibres have been used to impart viscosity, or for structuring purposes in low-fat
products like dressings. It was surprisingly found that some of the off-flavours (e.g.
"soy" and "cereal") of soy protein-containing drinks could be reduced when compared
to the same formulations using CMC, and that such products had a similar viscosity.
This would make the product especially suitable for applications wherein a soy protein
is used to prepare a ready-to-drink beverage, which soy protein is of a quality less
than the highest quality, as such products would be expected to have a stronger offflavour
in terms of "soy" and "cereal" notes than very high quality soy protein. Hence,
in the present invention it is preferred that the ready-to-drink, packaged nonfermented
soy-based beverage having a water content of at least 80 wt.%, a soy
protein content of 1.0-8.0 wt.%, a fat content of 0 to 5 wt.%, and which beverage
further comprises from 0.01 to 0.4 wt.% of insoluble cellulosic citrus fibres, and which
beverage has a viscosity of below 0.5 Pas at a shear rate between 2 and 100 s ,
when measured at 5°C, has a pH in the range of more than 5.5 and less than 8.
Herein, "non-fermented" is to be understood as a composition which has not been
fermented using bacteria, e.g. lactic acid bacteria. Hence, products such as soy
yoghurts and soy yoghurt drinks, i.e. products fermented with yoghurt culture, which,
according to the Codex Alimetarius, FAO/WHO 1977, include Lactobacillus bulgaricus
and Streptococcus thermophilus, are excluded from this invention.
Following being non-fermented , the beverage of the invention preferably comprises
no significant amount of lactic acid . Preferably, the beverage contains at less than
0.05 wt.% of lactic acid , more preferably less than 0.2 wt.% of lactic acid , most
preferably less than 0.4 wt.% of lactic acid .
The soy-based beverage of the present invention preferably has not been fermented
by lactic acid bacteria and/or Bifidobacterium.
Soy-based beverage herein means that the beverage comprises at least protein from
soy origin , and optionally other ingredients from soy beans as well. "Soy protein", as
used herein , refers to the total amount of soy protein and soy protein derived peptides
contained in the beverage. The beverage may be based on soy protein , on soy
protein hydrolysate or combinations thereof.
With beverage is meant herein a product which has (when measured at 20°C) a
viscosity of below 0.5 Pas at a shear rate between 2 and 100 s , when measured at
5°C. Preferably, the beverages according to the present invention have a viscosity of
below 0.3 Pas at a shear rate between 2 and 100 s , when measured at 5°C.
Viscosity for the beverages according to the present invention can suitably be
measured with the help of a rheometer AR1 000 (TA Instruments, the Netherlands),
between shear rates of 0.1- 1000s 1 with a cone and plate geometry, using a cone
having an angle of 2° and a gap set to 70, and at a temperature (controlled) of
5°C.
Cellulose is found in plants as microfibrils, which typically have a diameter of 2-20 nm
and a length of 100-40,000 nm. These form the structurally strong framework in the
cell walls of plant materials. Cellulose is a linear polymer of -(1 4)-D-glucopyranose
units. Cellulose molecules typically consist of between 2,000-1 4,000 of such units
and are completely insoluble in normal aqueous solutions. When dispersed in an
aqueous solution insoluble cellulosic fibres typically bind considerable amounts of
water. Cellulosic fibres may contain other fibrous components such as hemicelluloses,
pectins and lignin.
Purified cellulose is used as a starting material for the manufacture of a number of
water-soluble hydrocolloids, such as carboxymethyl cellulose (CMC). The manufacture
of these cellulose derivatives involves chemical modification of the natural cellulose
material. CMC, for instance, is synthesized by the alkali-catalyzed reaction of cellulose
with chloroacetic acid. The polar (organic acid) carboxyl groups render the cellulose
soluble and chemically reactive. Typically, the cellulosic fibres of the present invention
are substantially or completely underivatised. With respect to the insoluble cellulosic
citrus fibres, it is preferred that such are essentially non-hydrolysed. According to a
most preferred embodiment of the invention the insoluble cellulosic fibres are natural
cellulosic fibres which have not been chemically modified.
Unlike, for instance, microcrystalline cellulose, the cellulose molecules within the
present cellulosic fibres are essentially non-hydrolysed. Typically, the cellulose
molecules contained within the insoluble cellulosic fibres employed in accordance with
the present invention contain at least 1,000, preferably at least 2,000 -(14)- -
glucopyranose units, and are preferably non-depolymerised.
The insoluble cellulosic fibres in the present invention are insoluble citrus fibres. Most
preferably, the insoluble citrus fibres originate from the albedo and the flavedo of the
citrus fruits. The insoluble cellulosic fibres employed in the beverages of the present
invention preferably have a (volume mean diameter D4.3) particle size of above 10
m (micrometer), when measured using a Malvern Mastersizer (using a refractive
index of 1.45). Preferably, the cellulosic fibres herein have a particle size of size
(volume mean diameter D4.3) of above 20 (micrometer). Preferably, the cellulosic
fibres herein have a particle size of size (volume mean diameter D4.3) of below 200
(micrometer), more preferably below 150 (micrometer) and most preferably
below 100 (micrometer). Smaller sizes would require additional process steps to
break the bigger fibres down, which is a disadvantage.
Preferably, in the beverages according to this invention, the insoluble cellulosic fibres
have a water binding capacity of 6-30 wt.%.
As to the amount employed, it should neither be too much, to avoid a thick product,
nor too little for a good effect on mouthfeel and/or off flavour masking. Preferred
herein is to use the insoluble cellulosic fibres in an amount of from 0.03 to 0.1 wt.% on
the beverage.
A suitable cellulosic citrus fibre product for the present invention is Herbacel,
obtainable from Herbstreith & Fox GmbH, Germany. Also, such products are
described in WO 01/17376.
The invention is in particular suitable for non-dairy formulations (or at least low-dairy
formulations), which is an advantage for people allergic to them, strict vegetarians,
and others. Hence, it is preferred herein that the beverage contains less than 0.1% by
weight of dairy protein, and preferably is substantially free of dairy protein. Likewise,
the beverages according to the present invention preferably contain less than 0.1% by
weight of lactose, preferably is substantially free of lactose. This is an advantage as
some people are lactose intolerant.
Now soy and cereal off-tastes are suitably managed by the presence of certain fibres,
there is less or no need anymore for the presence of heavy fruit flavours, or even the
use of fruit juices, concentrates or purees and the likes to mask such off-flavours. This
makes the beverages in the present invention suitable as a neutral base product.
Following this, it is preferred that the beverages according to the present invention
comprises less than 2%, more preferably less than 1%, most preferably less than
0.7% of fruit or fruit-derived ingredients, based on dry weight of fruit or fruit
ingredients on the final beverage. Clearly, as the cellulosic fibres are of fruit origin,
and their presence is required, presence of some fruit-derived ingredients are allowed,
but preferably no other than the insoluble cellulosic citrus fibres herein defined.
The beverage according to the present invention are preferably substantially free of
fat-soluble vitamins.
In order to be suitable as a neutral base for e.g. further products (beverages), it is
preferred that the pH of the beverage is above 5.5 and below 8, preferably the pH is
above 6 and below 8, more preferably above 6 and below 7.5.
The beverage according to the present invention is preferably substantially free from
carboxy methyl cellulose, e.g. for processing reasons as set out hereinbefore. The
present invention enables the manufacture of soy-based beverages without using
high levels of pectins, notably low methoxy pectin and/or high methoxy pectin.
Consequently, in a preferred embodiment, the beverage contains less than 1% wt.%,
preferably less than 0.75 wt%, most preferably less than 0.5 wt% of a high methoxy
pectin.
The beverages of the invention preferably have a water content of at least 85 wt%,
most preferably at least 87 wt%, based on the total weight of the beverage.
The invention further relates to processes by which the products herein disclosed can
be prepared. Hence, the invention further relates to a process for providing a ready to
drink, packaged non-fermented soy-based beverage having a water content of at
least 80 wt.%, a soy protein content of 1.0-8.0 wt.%, a fat content of 0 to 5 wt.%, said
beverage further comprising from 0.01 to 0.4 wt.% of insoluble cellulosic citrus fibres,
said beverage having a viscosity of below 0.5 Pas at a shear rate between 2 and
100s 1 , which process comprises the steps of:
(a) providing a mixture comprising 1.0-8.0% soy protein, 0.01-0.4% wt of
insoluble cellulosic fibres and at least 80% wt of water
(b) subjecting said mixture to a heat-preservation step involving pasteurisation
or sterilisation
(c) packaging the product in containers of maximum 1.5 liter
whereby steps (b) and (c) may occur in any given order or simultaneously.
Preferably, in the above process, said soy-based beverage has a pH in the range of
more than 5.5 and less than 8.
The invention thus further relates to a process for providing a ready to drink,
packaged soy-based beverage having a water content of at least 80 wt.%, a soy
protein content of 1.0-8.0 wt.%, a fat content of 0 to 5 wt.%, said beverage further
comprising from 0.01 to 0.4 wt.% of insoluble cellulosic citrus fibres, said soy-based
beverage having a pH in the range of more than 5.5 and less than 8, said beverage
having a viscosity of below 0.5 Pas at a shear rate between 2 and 100s 1 , which
process comprises the steps of:
(a) providing a mixture comprising 1.0-8.0% soy protein, 0.01-0.4% wt of
insoluble cellulosic fibres and at least 80% wt of water
(b) subjecting said mixture to a heat-preservation step involving pasteurisation
or sterilisation
(c) packaging the product in containers of maximum 1.5 liter
whereby steps (b) and (c) may occur in any given order or simultaneously.
To the above two processes, the same preferred embodiments for e.g. the cellulosic
citrus fibres, the amount of soy protein, the presence or absence of other components
apply as to the compositions as set out above.
Examples
A model soy-protein containing beverage (level of soy protein about 5% by weight
based on the beverage) was prepared with the ingredients as in table 1 below: one
using CMC as a thickener, one using citrusfibres as a thickener.
Table 1
The CMC-containing beverages were prepared using the following processing. The
soy protein powder was dispersed in hot water (approx. 80°C). The soy was added
slowly under vigorous stirring using Ultra Turrax and left to hydrate for approximately
15 minutes. The calcium lactate and the salt were added to this slurry. The CMC slurry
was prepared by the addition of dry blended CMC and sugar. This was added slowly
to hot water (80°C) under vigorous stirring with Ultra Turrax. Care was taken that all
CMC was in solution and the slurry was left for approximately 20 minutes to hydrate.
Finally, the CMC and the soy slurries were mixed to yield final concentrations of
ingredients according to Table 1. The solution was pasteurised at 78°C for 43
seconds and homogenised at 180 bars.
The citrus fibre-containing beverages were prepared by dispersing the soy powder in
hot water (80°C). The soy was added slowly under vigorous stirring using Ultra Turrax
and left to hydrate for approximately 15 minutes. The calcium lactate, sugar and salt
were added to this slurry. The citrus fiber (CF) slurry was prepared addition of CF to
hot water (80°C). The slurry was mixed using UltraTurrax and left to swell for approx
20 minutes. Finally, the CF and the soy slurries were mixed to yield final
concentrations of ingredients according to Table 1. The solution was pasteurised at
78°C for 43 seconds and homogenised at 180 bars.
The samples were subjected to viscosity measurements and to a panel test for
evaluating the flavour. Viscosity was measured using a rheometer AR1 000 (TA
Instruments, the Netherlands), between shear rates of 0.1-1000s with a cone and
plate geometry. The cone had an angle of 2° and the gap was set to 70. The
temperature was controlled by a Peltier system and set to 5°C. The results are set out
in figure 1. In figure 1: sample with 0.05% added citrus fibre (CF, open symbol) and
0.05% added CMC (closed symbol).
The panel test for evaluating the flavour was conducted along the following lines. The
panel consisted of 14 trained panelists which were asked the question whether any
difference (R-index test) was found between sample 1a and 1b after which a
qualitative discussion was held. The panel found a difference between sample 1a and
1b with an R index of 63.1 . The results from the qualitative discussion is summarized
in Table 2.
Table 2
No ANOVA was done on the results due to the quantitative approach, nevertheless,
the results indicate that the CF containing sample (1a) is perceived as less slimey and
thick then the CMC containing sample ( 1b) despite the viscosity being similar (Figure
1) . Furthermore, the CF containing sample is perceived as having less soy and cereal
off notes compared to the CMC sample.
The viscosity data show that a beverage containing 5% soy protein can be prepared
that has a slightly increased viscosity, and that citrus fibres can achieve a similar
viscosity and viscosity profile as CMC.
The panel test shows that "soy" and "cereal" notes are reduced for the beverage of
table 1 containing citrus fibres, as compared to that containing CMC. Hence,
surprisingly, at such soy protein levels citrus fibres are capable of masking or
suppressing soy and cereal off notes (better than CMC can).
Claims
1. A ready to drink, packaged non-fermented soy-based beverage having a water
content of at least 80 wt.%, a soy protein content of 1.0-8.0 wt.%, a fat content
of 0 to 5 wt.%, said beverage further comprising from 0.01 to 0.4 wt.% of
insoluble cellulosic citrus fibres, said beverage having a viscosity of below 0.5
Pas at a shear rate between 2 and 100s 1 .
2. A beverage according to claim 1, wherein said packaged non-fermented soybased
beverage has a pH in the range of more than 5.5 and less than 8.
3. A beverage according to any of the preceding claims, wherein said beverage
has a viscosity of below 0.3 Pas at a shear rate between 2 and 100 s
4. A beverage according to any of the preceeding claims, wherein the cellulosic
citrus fibres are essentially non-hydrolysed.
5. A beverage according to any of the preceeding claims, wherein the cellulosic
citrus fibres are substantially underivatised.
6. A beverage according to any one of the preceding claims, wherein the
cellulose molecules contained within the insoluble cellulosic citrus fibres
contain at least at least 1,000, preferably at least 2,000 -(14)- -
glucopyranose units.
7. A beverage according to any of the preceding claims, wherein the cellulosic
citrus fibres have a particle size (volume mean diameter D4.3) of above 10
micrometer, and preferably between of between 10 and 200 micrometer.
8. A beverage according to any of the preceeding claims, wherein the amount of
insoluble cellulosic fibres is from 0.03 to 0.1 wt.%.
9. A beverage according to any of the preceeding claims, wherein the beverage
contains less than 0.1% by weight of dairy protein, preferably is substantially
free of dairy protein.
10. A beverage according to any of the preceeding claims, wherein it contains less
than 2%, preferably less than 1%, more preferably less than 0.7% of fruit or
fruit-derived ingredients, based on dry weight of fruit or fruit ingredients on the
final beverage.
11.A beverage according to any of the preceeding claims, wherein the beverage
contains less than 0.1% by weight of lactose, preferably is substantially free of
lactose.
12. A beverage according to any of the preceeding claims, wherein the pH of the
beverage is above 5.5 and below 8, preferably the pH is above 6 and below
7.5.
13. A beverage according to any of the preceeding claims, wherein it is
substantially free from carboxy methyl cellulose.
14. A process for providing a ready to drink, packaged non-fermented soy-based
beverage having a water content of at least 80 wt.%, a soy protein content of
1.0-8.0 wt.%, a fat content of 0 to 5 wt.%, said beverage further comprising
from 0.01 to 0.4 wt.% of insoluble cellulosic citrus fibres, said beverage having
a viscosity of below 0.5 Pas at a shear rate between 2 and 100s 1 , which
process comprises the steps of:
a. providing a mixture comprising 1.0-8.0% soy protein, 0.01-0.4% wt of
insoluble cellulosic fibres and at least 80% wt of water
b. subjecting said mixture to a heat-preservation step involving
pasteurisation or sterilisation
c . packaging the product in containers of maximum 1.5 liter
whereby steps (b) and (c) may occur in any given order or simultaneously.
15. A process according to claim 14, wherein said soy-based beverage has a pH
in the range of more than 5.5 and less than 8.