PRODUCT COMPRISING CATECHINS
TECHNICAL FIELD OF THE INVENTION

The present invention relates to products comprising catechins. In particular the invention
relates to the use of solids from Aspalathus linearis for providing improved products
comprising catechins.

BACKGROUND OF THE INVENTION

Tea has recently gained wide attention for its potentially beneficial effects on human
health. Several epidemiological, clinical and experimental studies have established a
positive correlation between tea consumption and certain health benefits. Taken regularly,
tea has been reported to help improve vascular function, combat fatigue, reduce
cholesterol levels and increase feelings of vitality.
The health benefits of tea are primarily attributed to its high polyphenol content. Catechins,
which include epigallocatechin gallate (EGCG), epicatechin (EC), epicatechin gallate
(ECG), and epigallocatechin (EGC), are the major polyphenolic compounds in green tea.
A positive correlation between catechin consumption and improved cardiovascular health
has been established, and their use as antiallergic agents and cerebral function activators
has been proposed.
Although some of the health benefits of tea may be apparent at consumption rates as low
as three cups per day (see, for example, U. Peters etal., "Does tea affect cardiovascular
disease? A meta-analysis.", American Journal of Epidemiology, 2001 , 154: pp.495-503),
many individuals do not even achieve this modest consumption rate on a long term basis.
There have been several attempts to provide products with enhanced levels of catechins.
Unfortunately, however, the incorporation of increased amounts of catechins can lead to
products that have poor taste characteristics.
European patent EP 1 297 749 B 1 (Kao Corporation) discloses a beverage with a
concentrated or purified tea extract incorporated therein. The beverage, which contains
catechins in combination with quinic acid at a predetermined ratio, is said to have an
improved taste. More specifically, the beverage is said to be free from the unpleasant
aftertaste which would otherwise remain after alleviation of the bitterness or astringency
peculiar to catechins by a sweetener or the like. However, the beverages disclosed
therein require the addition of quinic acid, which may itself bring unwanted taste to the
beverage. Furthermore, the beverages are still unpleasantly bitter, especially for
consumers used to tea-based beverages having relatively low levels of catechins, such as
black tea.
Thus we have recognised that there is a need to provide a product which delivers the
benefits of high levels of catechins, and which has improved taste, especially in respect of
bitterness and/or astringency. We have found that the use of solids from Aspalathus
linearis (rooibos) unexpectedly allows for the formulation of a product with excellent taste
characteristics even when elevated levels of catechins are incorporated therein.
TESTS AND DEFINITIONS
As used herein the term "comprising" encompasses the terms "consisting essentially of
and "consisting of. All percentages and ratios contained herein are calculated by weight
unless otherwise indicated. It should be noted that in specifying any range of values or
amount, any particular upper value or amount can be associated with any particular lower
value or amount.
The disclosure of the invention as found herein is to be considered to cover all
embodiments as found in the claims as being multiply dependent upon each other
irrespective of the fact that claims may be found with multiple dependency or redundancy.
Aspalathus linearis
Aspalathus linearis (also known as rooibos or redbush) is a shrub-like leguminous bush
native to the Western Cape region of South Africa, where it is extensively cultivated for
commercial use as a herbal tea. As used herein the terms "solids from Aspalathus
linearis" and "rooibos solids" are used interchangeably and refer to dry material extractable
from the leaves and/or stems of the plant Aspalathus linearis. The term "rooibos extract"
refers to an extract that comprises solids from Aspalathus linearis.
Catechins
The term "catechins" is used herein as a generic term for epicatechins, non-epicatechins,
and mixtures thereof. The term "epicatechins" refers to epicatechin, epigallocatechin,
epichatechin gallate, epigallocatechin gallate and mixtures thereof. The term "nonepicatechin"
refers to catechin, gallocatechin, catechin gallate, gallocatechin gallate and
mixtures thereof.
Beverage
As used herein the term "beverage" refers to a substantially aqueous drinkable
composition suitable for human consumption. Preferably the beverage comprises at least
85% water by weight of the beverage, more preferably at least 90% and most preferably
from 95 to 99.9%.
As used herein the term "packaged" means that the beverage is contained within a sealed
package. Non-limiting examples of suitable packages include bottles, cans, cartons,
pouches and sachets.
Tea-based beverage
As used herein the term "tea-based beverage" refers to a beverage comprising at least
0.01 % tea solids by weight of the beverage. Preferably the tea-based beverage
comprises from 0.04 to 3% tea solids, more preferably from 0.06 to 2%, most preferably
from 0.1 to 1%.
Tea solids
As used herein the term "tea solids" refers to dry material extractable from the leaves of the
plant Camellia sinensis var. sinensis and/or Camellia sinensis var. assamica. The leaves
may have been subjected to a so-called "fermentation" step wherein they are oxidised by
certain endogenous enzymes that are released during the early stages of "black tea"
manufacture. This oxidation may even be supplemented by the action of exogenous
enzymes such as oxidases, laccases and peroxidises. Alternatively the leaves may have
been partially fermented ("oolong tea") or may have remained substantially unfermented
("green tea").
Determination of titratable acidity
Titratable acidity is a measure of the total amount of free acid present in a sample. It is
determined by titration using a standard solution of sodium hydroxide (NaOH) as
described below.
Sodium Hydroxide neutralises free acid, giving an increase in pH. The amount of sodium
hydroxide required to raise the sample pH to 8.3 is proportional to the amount of free acid
in the sample. Free acid in samples should be measured in units of g/L citric acid
(anhydrous).
Apparatus
10 ml_ pipette.
25 ml_ burette.
pH meter (compatible with Orion Ross Sure-Flow electrode 8 1-65, or similar).
0.1 mol/L sodium hydroxide solution.
4 g/L citric acid (anhydrous) standard.
Preparation of equipment
1. The pH meter and electrode should be set up as per the manufacturer's instructions.
2. The burette must be rinsed with, and then filled with 0.1 M NaOH.
3. The actual strength of the NaOH should be checked by titrating a sample of 4 g/L citric
acid. This must be carried out daily, or when a new batch of NaOH is produced.
Titration of sample
1. Pipette 10 ml of sample into a suitable beaker.
2. Insert electrode.
3. Add sodium hydroxide, while continually stirring, until a stable reading of pH 8.3 is
achieved.
Calculation of results
Titratable acidity is expressed in terms of citric acid equivalents [i.e. g/L citric acid
(anhydrous)]. The titratable acidity of a sample can be calculated as follows:
_ . . . . . Titre Volume NaOH Concentration 1000 • ,
Titratable Acidity = x x x RMM oj Acid
1000 Valency of Acid Sample Volume
NaOH concentration 0.1 mol/L
RMM of citric acid (anhydrous) 192.12 g/mol
Valency of citric acid 3
Sample volume 10 mL
For a sample this is equivalent to:
, , . . . Titre Volume 0.1 1000 Titratable Acidity = x — x x 192. 12
1000 3 10
where the titre volume is the volume of 0.1 M NaOH (in mL) required to raise the sample
pH to 8.3, and the result is expressed as g/L citric acid (anhydrous).
For the measurement of carbonated samples, testing must be preceded by full degassing,
as dissolved CO2 gives erroneous results by forming carbonic acid. Vacuum de-gassing
of still products is not required.
SUMMARY OF THE INVENTION
In a first aspect, the present invention provides a product comprising solids from
Aspalathus linearis and at least 50 mg catechins, characterised in that the ratio of solids
from Aspalathus linearis to catechins is from 10:1 to 1:20.
We have found that the use of solids from Aspalathus linearis allows the formulation of
products with excellent taste characteristics that enable consumers to meet the daily intake
of catechins required to achieve health benefits. In particular, we have found that use of
solids from Aspalathus linearis can be used to alleviate the bitterness and/or astringency of
catechins.
In order to prepare a product which contains a high level of catechins without being
unpleasantly bitter and/or astringent, we have found that it is necessary to control the
relative concentration of catechins and solids from Aspalathus linearis. Therefore, in
products according to the current invention the ratio of solids from Aspalathus linearis to
catechins is from 10:1 to 1:20. Preferably the ratio of solids from Aspalathus linearis to
catechins is from 5:1 to 1:10, more preferably from 2:1 to 1:5, most preferably from 1:1 to
1:4.
In another aspect, the present invention provides use of solids from Aspalathus linearis for
reducing or eliminating bitterness and/or astringency of catechins.
In a further aspect, the present invention provides a method of manufacturing a product
comprising solids from Aspalathus linearis and catechins, wherein a substance comprising
the catechins is combined with a substance comprising the solids from Aspalathus linearis.
Preferably the substance comprising the catechins comprises tea solids, more preferably
green tea solids.
DETAILED DESCRIPTION
The product of the present invention may be a food or a beverage product, or a precursor
for preparing such a product. Preferably the product is a beverage, more preferably it is a
packaged tea-based beverage.
Products according to the present invention comprise solids from Aspalathus linearis and
at least 50 mg catechins. The total catechin content of the product is preferably such that
consumers can meet the daily intake of catechins required to achieve health benefits in
one or two servings. Therefore, a serving comprises at least 50 mg catechins, preferably
at least 100 mg, more preferably at least 150 mg and most preferably from 200 mg to
1000 mg.
Preferably the product comprises at least 0.1% ( 1 mg/g) catechins by dry weight, more
preferably at least 1% (10 mg/g), still more preferably at least 3% (30 mg/g) and most
preferably from 7% (70 mg/g) to 100% ( 1000 mg/g). It is preferred that the total dry weight
of the product is less than 200 g, more preferably from 0.5 g to 100 g, still more preferably
from 1 g to 50 g.
The mass of the product required to deliver suitable amounts of catechins to a consumer
will depend on the format of the product and the catechin content of the product. For
convenience of transport and handling it is preferred that the product has a total mass of
0.5 g to 2 100 g, more preferably 1 g to 1100 g and most preferably 2 g to 550 g.
In products according to the present invention, the catechins may comprise epicatechins,
non-epicatechins, or a mixture thereof. Natural sources of catechins (e.g. tea leaves,
cocoa beans) comprise a mixture of epicatechins and non-epicatechins. Thus, it is
preferred that the catechins comprise both epicatechins and non-epicatechins.
We have found that the use of solids from Aspalathus linearis in combination with
catechins is well-suited to delivering a beverage that is not bitter. Thus in a preferred
embodiment the product is a beverage, preferably a tea-based beverage, more preferably
a green tea-based beverage. It is also envisaged that the product of the invention may be
a beverage precursor.
In order to control the perception of sour taste, initial bitterness and/or bitterness aftertaste,
it preferred that the titratable acidity of the product is from 0.1 to 3.0, more preferably from
0.3 to 2.0, still more preferably from 0.3 to 1.5 and most preferably from 0.5 to 1.3. The
titratable acidity will depend on the format and composition of the product. In one
embodiment, the titratable acidity of a beverage product may be controlled by varying the
amount of citric acid and/or malic acid in the formulation.
From a standpoint of microbial stability and taste, it is preferred that the product has an
acidic pH. In particular, the pH (at 20°C) may be from 2 to 7, more preferably from 2 to 5,
most preferably from 2.5 to 4.
The product of the present invention may be manufactured by any suitable means. The
product is preferably manufactured by a method wherein a substance comprising
catechins is combined with a substance comprising solids from Aspalathus linearis.
Preferably the substance comprising catechins comprises tea solids, more preferably
green tea solids.
[EXAMPLES
The present invention will now be illustrated by reference to the following non-limiting
examples.
Example 1
Solids from Aspalathus linearis ("rooibos solids") were assessed for their ability to mask the
bitterness of catechins. Products comprising catechins and different types of tea solids
from Camellia sinensis (white tea, oolong tea, black tea) were also assessed. A high
catechin tea powder (Sunphenon 90XLB, supplied by Taiyo Kagaku KK) was used to
adjust the catechin content of each of the products to 645 mg/L.
Products containing equivalent amounts of catechins were qualitatively assessed on their
bitterness and astringency by 6 untrained individuals in informal tasting sessions. The
individuals did not know the composition of the products presented. Products comprising
rooibos solids (385 mg/L) and catechins were perceived as being noticeably less bitter
than products comprising catechins and tea solids.
Example 2
Five beverage products were prepared according to an established formulation comprising
sweeteners, flavourings and preservatives. Green tea powder (Ceytea™ from Premium
Exports Ceylon Ltd) was included in each beverage product to provide a uniform amount
of catechins. Solids from Aspalathus linearis (provided by rooibos extract I) were present
in products 3, 4 and 5 (see Table 1) . Additionally, the titratable acidity of the products
controlled by varying the amounts of citric and malic acids contained therein.
TABLE 1
*Ceytea from Premium Exports Ceylon Ltd (Sri Lanka).
+From Plantextrakt GmbH & Co. KG.
*Ceytea™ specification: 270 mg g catechins.
†Rcoibos extract I specification: 35% solids from Aspalathus linearis.
**Weight ratio of solids from Aspalathus linearis to catechins.
The beverage products were filled into 330 ml cans and sealed. The cans were then
pasteurised at 70°C for 10 minutes in a batch pasteuriser.
The beverage products were evaluated by a taste panel comprising trained panellists.
The results of the evaluations (trial A and trial B) are discussed below. Trial A and trial B
were conducted separately on different dates.
In trial A, product 1 (a high catechin beverage product that is reported by consumers as
having a perceptibly bitter taste) was compared with products 2, 3 and 4. Product 1 was
judged to have the highest initial bitterness of all the products tasted in trial A . Product 4
was judged to have the lowest initial bitterness, and was significantly (p <0.05) lower in
initial bitterness than product .
Product 1 was judged to have the lowest sweetness of all the products tasted in trial A and
products 2 and 4 were both significantly (p <0.05) higher in sweetness than product 1. In
agreement with this finding, product 1 was also ranked most sour, with products 2 and 4
both being judged to be significantly (p <0.05) less sour than product 1.
Additionally, product 4 was judged to have the smoothest mouthfeel, while product 1
ranked lowest in smoothness. Products 3 and 4 were both significantly higher in
smoothness than product 1 (p <0.05).
In trial B, product 1 was compared with products 4 and 5. Product 1 was judged to have
the highest initial bitterness of all the products tasted in trial B. Product 4 was judged to
have the lowest initial bitterness, and product 5 was also directionally lower in initial
bitterness than product 1.
Product 1 was judged to be the most sour of all the products tasted in trial B, with products
4 and 5 both being judged to be significantly (p <0.05) less sour than product 1. In
agreement with this finding, product 1 was also judged to have the lowest sweetness, with
products 4 and 5 both directionally higher in sweetness than product 1. Additionally,
product 4 was judged to have the smoothest mouthfeel, while product 1 ranked lowest in
smoothness. Product 5 was directionally higher in smoothness than product 1.
Example 3
Six beverage products were prepared according to an established formulation comprising
sweeteners, flavourings and preservatives. Green tea powder (Ceytea™ from Premium
Exports Ceylon Ltd) was included in each beverage product to provide a uniform amount
of catechins. Solids from Aspalathus linearis were present in products 4, 6, 7 and 8 (see
Tables 1 and 2). Additionally, the titratable acidity of the products was controlled by
varying the amounts of citric and malic acids contained therein (see Tables 1 and 2).
The beverage products were filled into 330 ml cans and sealed. The cans were then
pasteurised at 70°C for 10 minutes in a batch pasteuriser.
TABLE 2
*Ceytea from Premium .Exports Ceylon Ltd, Sri Lanka (270 mg/g catechins).
+From Plantextrakt GmbH & Co. KG (36% rooibos solids).
*From Afriplex (Pry) Ltd. (100% rooibos solids).
From Afriplex (Pty) Ltd. (30% rooibos solids).
Product 1 is a high catechin beverage product that is judged to have a perceptibly bitter
taste. Products 4, 6, 7 and 8 (collectively referred to as "rooibos products") all contain 75
mg/L rooibos solids. As can be seen from Tables 1 and 2, the rooibos products utilise
different rooibos extracts (I, II, III and IV) to provide the rooibos solids.
The beverage products were evaluated by a taste panel comprising trained panellists.
The results of the evaluation (trial C) are discussed below.
Product 1 was judged to have the highest initial bitterness of all the products tasted in trial
C. Product 4 was judged to have the lowest initial bitterness, and the rooibos products
were all directionally lower in initial bitterness than product 1. Product 1 was also judged to
be the most sour of all the products tasted in trial C. The rooibos products were all judged
to be significantly (p <0.05) less sour than product 1.
Additionally, the mouthfeel of product 1 was assessed as being significantly (p <0.05) less
smooth and less thick than the rooibos products. Product 4 was directionally smoother
and thicker than the other rooibos products (i.e. products 6, 7 and 8).
The data from trial C indicate that the four rooibos products are not significantly different to
each other in taste, flavour or mouthfeel. This implies that the presence of rooibos solids
(regardless of their source) is important when it comes to formulating high catechin
products with excellent taste characteristics.
CLAIMS
1. A product comprising solids from Aspalathus linearis and at least 50 mg catechins,
characterised in that the ratio of solids from Aspalathus linearis to catechins is from
10:1 to 1:20.
2. A product as claimed in claim 1 wherein the product comprises at least 0.1%
catechins by dry weight.
3. A product as claimed in any one of the preceding claims wherein the product is a
beverage.
4. A product as claimed in claim 3 wherein the product is a packaged tea-based
beverage.
5. A product as claimed in claim 3 or claim 4 wherein the product has a titratable acidity
of from 0.1 to 3.0.
6. A product as claimed in any one of claims 3 to 5 wherein the product has a pH of
from 2 to 7.
7. A product as claimed in any one of the preceding claims wherein the catechins
comprise epicatechins, non-epicatechins or a mixture thereof.
8. A product as claimed in any one of the preceding claims wherein ratio of solids from
Aspalathus linearis to catechins is from 5:1 to 1:1 0.
9. A product as claimed in any one of the preceding claims wherein the product has a
titratable acidity of 0.3 to 2.0.
10. A product as claimed in any one of the preceding claims wherein the product has a
total mass of 0.5 g to 2 100 g.
11. Use of solids from Aspalathus linearis for reducing or eliminating bitterness and/or
astringency of catechins.
12. A method of manufacturing a product comprising solids from Aspalathus linearis and
catechins, wherein a substance comprising the catechins is combined with a
substance comprising the solids from Aspalathus linearis.
13. A method of manufacturing a product according to claim 12 wherein the substance
comprising the catechins comprises tea solids.
14. A method of manufacturing a product according to claim 12 or claim 13 wherein the
product comprises solids from Aspalathus linearis and catechins in a ratio of from
10:1 to 1:20.
15. A method of manufacturing a product according to any one of claims 12 to 14
wherein the product comprises at least 50 mg catechins.