U.S. patent application number 14/900070 was filed with the patent office on 2016-06-02 for a smokeless tobacco composition and a method for its manufacture.
This patent application is currently assigned to SWEDISH MATCH NORTH EUROPE AB. The applicant listed for this patent is SWEDISH MATCH NORTH EUROPE AB. Invention is credited to Marten KINDVALL, Jorgen LUNDIN.
Application Number | 20160150816 14/900070 |
Document ID | / |
Family ID | 48782984 |
Filed Date | 2016-06-02 |
United States Patent
Application |
20160150816 |
Kind Code |
A1 |
KINDVALL; Marten ; et
al. |
June 2, 2016 |
A SMOKELESS TOBACCO COMPOSITION AND A METHOD FOR ITS
MANUFACTURE
Abstract
A smokeless tobacco or non-tobacco snuff composition for oral
use comprising at least 20 wt % water based on the total weight of
the final composition and at least 1 wt % lactic acid or a salt
thereof based on the dry weight of the final smokeless tobacco or
non-tobacco snuff composition, as well as a method for its
manufacture and the use of such composition.
Inventors: |
KINDVALL; Marten; (Goteborg,
SE) ; LUNDIN; Jorgen; (Upplands-Vasby, SE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SWEDISH MATCH NORTH EUROPE AB |
Stockholm |
|
SE |
|
|
Assignee: |
SWEDISH MATCH NORTH EUROPE
AB
Stockholm
SE
|
Family ID: |
48782984 |
Appl. No.: |
14/900070 |
Filed: |
June 19, 2014 |
PCT Filed: |
June 19, 2014 |
PCT NO: |
PCT/EP2014/062954 |
371 Date: |
December 18, 2015 |
Current U.S.
Class: |
131/290 ;
131/352 |
Current CPC
Class: |
A24F 23/02 20130101;
A24B 13/00 20130101; A24B 15/30 20130101 |
International
Class: |
A24B 13/00 20060101
A24B013/00; A24F 23/02 20060101 A24F023/02; A24B 15/30 20060101
A24B015/30 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 10, 2013 |
EP |
13175932.6 |
Claims
1. A smokeless tobacco or non-tobacco snuff composition for oral
use, comprising: at least 20 percent water based on the total
weight of the final composition, and at least one percent lactic
acid or a salt thereof based on the dry weight of the final
composition.
2.-14. (canceled)
15. The composition according to claim 1, wherein the composition
comprises at least 30 percent water based on the total weight of
the final composition.
16. The composition according to claim 1, wherein the composition
comprises less than four percent NaCl based on the dry weight of
the final composition.
17. The composition according to claim 1, wherein the composition
comprises less than one percent NaCl based on the dry weight of the
final composition.
18. The composition according to claim 1, wherein the composition
comprises at least six percent lactic acid or a salt thereof based
on the dry weight of the final composition.
19. The composition according to claim 1, wherein the composition
comprises at least ten percent lactic acid or a salt thereof based
on, the dry weight of the final composition.
20. The composition according to claim 1, wherein the lactic acid
or a salt thereof is sodium lactate.
21. The composition according to claim 1, wherein the composition
has a pH of at least 7.5 and less than 9.8.
22. The composition according to claim 1, wherein the composition
is a smokeless tobacco composition for oral use.
23. The composition according to claim 22, wherein the composition
is snus.
24. The composition according to claim 1, wherein the composition
does not comprise a preservative selected from the group consisting
of sorbates, propionates, and benzoic acid or salts thereof.
25. A method for manufacturing the smokeless tobacco or non-tobacco
snuff composition of claim 1, comprising: a) providing a tobacco or
non-tobacco plant material; b) processing the material provided in
step a); and c) adding lactic acid to the composition either
before, during, or after the processing step at one or more of the
following steps.
26. The composition according to claim 1, wherein the composition
is packaged into portion packets.
27. The composition according to claim 1, wherein the composition
is packaged into pouches.
Description
[0001] The present invention relates to a smokeless tobacco or
non-tobacco snuff composition for oral use comprising at least 1 wt
% lactic acid, or a salt thereof, based on the dry weight of the
smokeless tobacco composition, as well as a method for its
manufacture and the use of such composition.
BACKGROUND
[0002] Smokeless tobacco or non-tobacco snuff products for oral use
comprise finely divided, particulate, such as ground, or cut,
tobacco or non-tobacco material or a combination thereof that is
not intended for combustion but designed to be placed in the oral
cavity of a user for a period of time.
[0003] There are many various forms of smokeless tobacco or
non-tobacco products for oral use. Such forms include chewing
tobacco and tobacco or non-tobacco snuff. Snuff is available in two
forms, as dry snuff for oral or nasal use and moist (or wet) snuff.
There are two types of moist snuff, the American and the
Scandinavian type. American-type moist snuff is available in a
loose form or as pre-packed pouches and is typically used between
the lower gum and lip. The use of American-type moist snuff is
commonly called dipping. Snus is the Scandinavian-type of moist
snuff which is also available in loose form or as pre-packed
portions in pouches. Snus is typically used between the upper gum
and lip.
[0004] There are a number of properties of the smokeless tobacco or
non-tobacco snuff products for oral use that are very important for
the end user. Among them, the organoleptic properties, such as
texture, aroma, taste, form and package of the product, are of high
importance for the consumer.
[0005] There is a merit in offering a range of products with
different organoleptic properties to the consumers.
SUMMARY OF THE INVENTION
[0006] The present invention relates to a smokeless tobacco or
non-tobacco snuff composition for oral use comprising at least 1 wt
% lactic acid or a salt thereof based on the dry weight of the
smokeless tobacco composition. The invention further relates to a
method for manufacturing such composition, the use of such
composition and a pouch containing such composition.
[0007] The present invention is defined in the appended claims.
[0008] Thus, a first aspect of the present invention is a smokeless
tobacco or non-tobacco snuff composition for oral use comprising at
least 20 wt % water based on the total weight of the final
composition, wherein the composition further comprises at least 1
wt % lactic acid or a salt thereof based on the dry weight of the
final composition.
[0009] A second aspect of the present invention is a method for
manufacturing of a smokeless tobacco or non-tobacco snuff
composition comprising at least 20 wt % water based on the total
weight of the final composition and at least 1 wt % lactic acid or
a salt thereof based on the dry weight of the final composition,
wherein the method comprises: [0010] a) providing a tobacco or
non-tobacco plant material; [0011] b) processing the material
provided in step a) and optionally other ingredients; and [0012] c)
optionally packing the smokeless tobacco or non-tobacco snuff
composition, either in pouches, or as is, in cans, or boxes;
wherein lactic acid or a salt thereof is added at one or more of
the following steps: [0013] i) prior to step b), [0014] ii) during
step b), and/or [0015] iii) after step b).
[0016] A third aspect of the invention is the use of a smokeless
tobacco or non-tobacco snuff composition according to the first
aspect of the invention for making portion packets comprising said
composition.
[0017] A fourth aspect of the present invention is a pouch
containing a smokeless tobacco or non-tobacco snuff composition for
oral use according to the first aspect of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 shows the principle of the manufacturing process
according to GothiaTek.RTM. standard, as used for the manufacturing
of Scandinavian type moist snuff (snus).
[0019] FIG. 2 shows the bacterial growth in snus compositions
comprising different salts in various amounts, where the
compositions have been stored during 3 weeks at 22.degree. C., 60%
RH.
DETAILED DESCRIPTION OF THE INVENTION
[0020] It is intended throughout the present description that the
expression "tobacco" stands for any part, e.g. leaves and stems, of
any member of the genus Nicotiana. The tobacco may be whole,
shredded, threshed, cut, ground, cured, aged, fermented, or
otherwise, e.g. granulated or encapsulated. Tobacco may also be in
the form of finished products, including any smokeless tobacco
composition that is orally consumed. Such smokeless tobacco
compositions include snuff and chewing tobacco.
[0021] "Non-tobacco snuff" as used herein is used for a snuff
composition that does not comprise tobacco but resembles a tobacco
snuff composition in that it has similar texture, color, taste,
flavor and mouthfeel. Non-tobacco snuff compositions are usually
based on non-tobacco plant fibers. Examples of non-tobacco plant
materials are oat fibers, apple fibers, sugar beet fibers, potato
fibers, corn fibers, buckwheat fibers, cocoa fibers, and cellulose
fibers. Smokeless non-tobacco snuff products for oral use are used
in the same manner as the corresponding smokeless tobacco products
for oral use.
[0022] Snuff is available in two forms, as dry nasal snuff for
sniffing, and moist (or wet) snuff, such as snus, for use in the
oral cavity by placing between the lip and gum.
[0023] Dry snuff for nasal use have a low water content, typically
less than 10 wt %, and is commonly made from fire-cured fermented
tobacco. The tobacco is ground into a powder and optionally other
ingredients are added.
[0024] American-type moist snuff for oral use is commonly produced
through a fermentation process of moisturized ground or cut
tobacco. The water content is typically greater than 40 wt %.
American-type moist snuff is available in a loose form or as
pre-packed pouches and is most commonly used between the lower gum
and lip but could also be used as snus between the upper gum and
lip.
[0025] "Snus" as used herein denotes the Scandinavian type of moist
snuff for oral use, which is produced in a heat-treatment process
instead of by fermentation. The tobacco or non-tobacco snuff
product may be provided in particulate form, as a loose powder, or
portion packed in a pouch. The final water content is typically
greater than 40 wt %, but semi-dry products having less than 40 wt
% water content, such as a water content from about 20 wt %, are
also available. Snus is typically used between the upper gum and
lip.
[0026] "Oral" and "oral use" is in all contexts used herein as a
description for use in the oral cavity, i.e. chewing purposes, or
buccally placement, such as between the lip and gum.
[0027] As used herein, the expression "water content" means the
total water content in a smokeless tobacco or non-tobacco snuff
composition including natural water contained in the materials used
in the composition, as well as added pure water, as measured by
using a standardized method for water analysis, such as, Karl
Fischer titration or gas chromatography (GC). The water content is
given herein as percent by weight (wt %).
[0028] Smokeless tobacco or non-tobacco snuff products for oral use
may have a water content ranging from around 10 wt % for very dry
products and up to about 65 wt % based on the total weight of the
final composition, usually from 20 to 60 wt %, or from 30 to 60 wt
%. The water holding capacity of the tobacco or non-tobacco snuff
compositions affects the moist feeling of the product. A
composition having a high water holding capacity can feel more dry
than a composition with a lower water holding capacity, although
both compositions have the same water content. Some consumers
prefer products that are more dry while others prefer more moist
products.
[0029] "Water activity" (a.sub.w) is defined as the vapour pressure
above a sample divided by the vapour pressure of pure water at the
same temperature. The water activity is related to the water
content of a sample in a non-linear relationship. Water activity
values are obtained by either a capacitance or a dew point
hygrometer. The water activity, as used herein, is measured with a
Decagon AquaLab series 3 instrument that employs a cold mirror/dew
point technique and is calibrated with certified standard
solutions.
[0030] The term "dry weight", as used herein, incorporates the
common usage of the term and, in the context of the smokeless
tobacco or non-tobacco snuff products disclosed herein, means the
weight of a smokeless tobacco or non-tobacco snuff product after
substantially all of the water or any other liquid has been
removed.
[0031] The smokeless tobacco or non-tobacco snuff composition for
oral use according to the present invention comprises at least 20
wt %, at least 25 wt %, at least 30 wt %, at least 35 wt %, at
least 40 wt %, at least 50 wt % water, or at least 55 wt % water,
based on the total weight of the final composition, and at least 1
wt % lactic acid or a salt thereof based on the dry weight of the
final composition.
[0032] The composition according to the present invention may
comprise not more than 70 wt % water, or not more than 65 wt %, or
not more than 60 wt % water, based on the total weight of the final
composition.
[0033] A particular problem for the manufacturing of semi-dry and
moist smokeless tobacco or non-tobacco snuff products, such as
products containing about 20 wt % water or more, for example
products containing about 30 wt % water or more, based on the total
weight of the final composition, is to provide a composition
wherein microbial growth is avoided. The water activity of a
composition is one important factor known to affect the microbial
growth (L. B. Rockland, et al.: Water activity: Theory and
application to food, IFT Basic Symposium Series. Marcel Dekker Inc.
ISBN 0-8247-7759-X; and G. L. Robertson, Food Packaging. Principles
and Practise, Marcel Dekker inc. ISBN 0-8247-0175-5).
[0034] Sodium chloride, NaCl, is an additive used in moist
smokeless tobacco or non-tobacco snuff compositions for oral use as
a preservative for preventing microbial growth, such as growth of
bacteria, in general by decreasing the water activity. The use of
sodium chloride may render the composition a salty taste.
[0035] The natural occurrence of NaCl in tobacco, such as in
tobacco lamina and stem, is below 1 wt %, typically below 0.5 wt %
based on the dry weight of the tobacco.
[0036] The amount of NaCl needed to achieve an antimicrobial effect
depends on the water content of the smokeless tobacco or
non-tobacco snuff composition.
[0037] Smokeless tobacco or non-tobacco snuff compositions
comprising less than 20 wt % water based on the total weight of the
final composition may not need any addition of NaCl in order to
prevent microbial growth. However, commercially available smokeless
tobacco or non-tobacco snuff compositions for oral use that
comprises more than 20 wt % water, based on the total weight of the
final composition, typically comprise at least 4 wt % NaCl, based
on the dry weight of the final composition while compositions
comprising more than 50 wt % water based on the total weight of the
final composition typically comprise more than 8 wt % NaCl based on
the dry weight of the final composition. These amounts of NaCl are
usually needed to achieve an antimicrobial effect. However, a
composition comprising such amount of NaCl may be perceived too
salty by many consumers.
[0038] By reducing the content of NaCl in a smokeless tobacco or
non-tobacco snuff composition for oral use it may obtain a less
salty taste, but it would also be expected that the water activity
(a.sub.w) would increase, and also the probability for microbial
growth, compared with a corresponding composition having the same
water content but a greater content of NaCl. When the a.sub.w is
above 0.90 for a smokeless tobacco or non-tobacco snuff composition
for oral use, such as in compositions with a relatively high water
content, for example comprising at least 30 wt % water based on the
total weight of the final composition, such as Swedish snus, the
risk for microbial growth in the product increases. An a.sub.w of
0.92 would normally result in strong microbial growth.
[0039] Compositions according to the present invention show
negligible or a very limited microbial growth even though these
compositions may have an increased water activity, such as an
a.sub.w of 0.92.
[0040] An advantage with lactic acid or a salt thereof is that it
has a neutral taste in addition to its ability to limit the
microbial growth in a composition according to the present
invention.
[0041] The amount of lactic acid or a salt thereof that is needed
in a smokeless tobacco or non-tobacco snuff composition for oral
use to provide a desired water activity and to achieve an
antimicrobial effect depends on the water content of the
composition and, if NaCl is added, the amount of NaCl.
[0042] The smokeless tobacco or non-tobacco snuff composition for
oral use according to the present invention comprises at least 1 wt
% lactic acid or a salt thereof, at least 2 wt %, at least 3 wt %,
at least 4 wt %, at least 5 wt %, at least 6 wt %, at least 7 wt %,
at least 10 wt %, at least 12 wt %, at least 15 wt %, or at least
20 wt %, based on the dry weight of the final composition. The
natural occurrence of lactic acid or a salt thereof in smokeless
tobacco or non-tobacco snuff composition for oral use is typically
below 1 wt %, or even below 0.5 wt %.
[0043] The composition according to the present invention may
comprise not more than 30 wt % lactic acid or a salt thereof, not
more than 25 wt %, or not more than 20 wt %, based on the dry
weight of the final composition.
[0044] Salts of lactic acid that are suitable in the composition
according to the present invention may be lactate salts of an
alkali metal, such as sodium lactate or potassium lactate, and more
specifically sodium lactate.
[0045] An advantage with a smokeless tobacco or non-tobacco snuff
composition for oral use according to the present invention is that
by adding lactic acid or a salt thereof, the amount NaCl in a
composition may be lowered without risk for increased microbial
growth. Compositions according to the present invention may
therefore be provided with a less salty taste compared to
corresponding compositions without lactic acid or a salt thereof,
while the microbial growth is maintained at the same level.
[0046] A smokeless tobacco or non-tobacco snuff composition
according to the present invention may comprise less than 8 wt %
NaCl, less than 4 wt % NaCl, or less than 1 wt % NaCl, based on the
dry weight of the final composition.
[0047] With the use of lactic acid or a salt thereof in a smokeless
tobacco or non-tobacco snuff composition according to the present
invention it is possible to achieve an antimicrobial effect even
without any addition of NaCl.
[0048] The greater the amount of water and the lower the amount of
NaCl in a tobacco or non-tobacco snuff composition for oral use,
the greater amount of lactic acid may be required to avoid
microbial growth.
[0049] Lactic acid and salts thereof have been reported to decrease
microbiological growth at a low pH, such as pH 7.25 or lower (De
Wit, J. C., et al. 1990, Food Microbiol., 7:113-120; and Shelef, L.
A. 1994, J. Food Prof., 57:445-450). Further reports show that the
antimicrobial effect tends to increase with lower pH (Houtsma,
1996, Ph.D. thesis, Agricultural University Wageningen). In an
acidic environment lactic acid is undissociated, and can diffuse
into the microbial cell wherein it subsequently has an
antimicrobial effect.
[0050] The pH of smokeless tobacco or non-tobacco snuff
compositions for oral use is typically higher than pH 7.5,
typically higher than pH 8. Therefore it was not expected that a
composition according to the present invention would show a
negligible microbial growth, as is shown in Table 1 and FIG. 2.
[0051] The smokeless tobacco or non-tobacco snuff composition for
oral use according to the present invention may have a pH of at
least 7.5, or at least 8. The pH may not be higher than 9.8, or
preferably not higher than 9.5. The composition preferably has a pH
in the range from 7.5 to 9.8, or in the range from 8 to 9.5.
[0052] Another advantage with the use of lactic acid or a salt
thereof in the smokeless tobacco or non-tobacco snuff composition
of the present invention is that they might be used in effective
amounts without being subject to regulatory restrictions. Other
preservatives, such as salts of sorbic and propionic acids, may be
subject to regulatory requirements in certain jurisdictions and may
not provide any antimicrobial effect even when used at their
maximal allowed concentration according to said regulation
requirements. With a composition according to the present invention
the amount of preservatives, such as sorbates, e.g. potassium
sorbate; propionates, e.g. sodium propionate; or benzoic acid or
salts thereof may be completely avoided or reduced without
increasing the risk for microbial growth. Thus, the smokeless
tobacco or non-tobacco snuff compositions for oral use according to
the present invention may comprise no preservatives selected from
the group consisting of sorbates, propionates, and benzoic acid or
salts thereof.
[0053] A further advantage of using of lactic acid or a salt
thereof in the smokeless tobacco or non-tobacco snuff composition
of the present invention is that it alters the consistency of the
composition so that it becomes more cohesive than a composition
with the same water content but without lactic acid or a salt
thereof. Thus, the water content of the composition according to
the present invention can be reduced while preserving the same
consistency as perceived by the consumer. A reduced water content
has the further advantage that it also may contribute to a reduced
microbial growth since the water activity will be decreased.
[0054] A more cohesive texture of smokeless tobacco or non-tobacco
snuff compositions for oral use with a reduced water content may
also be an advantage during manufacture, such that it is possible
to pack in pouches at a lower water content than would normally be
possible. A process for making pouches of a smokeless tobacco or a
non-tobacco snuff composition for oral use is described in U.S.
Pat. No. 6,135,120.
[0055] Further, because of the increased cohesive texture when
lactic acid or a salt thereof is added to a smokeless tobacco or
non-tobacco snuff composition for oral use according to the present
invention it is easier to form the composition into a portion
packet or a pinch, compared with a corresponding composition for
oral use with the same water content but without the addition of
lactic acid or a salt thereof.
[0056] The composition for oral use according to the present
invention is preferably a smokeless tobacco composition, such as
snus.
[0057] The smokeless tobacco or non-tobacco snuff composition for
oral use according to the present invention may be provided in form
of pouches, or as is in particular form in cans or boxes.
[0058] A general description of snus manufacturing is presented by
e.g. ESTOC, European Smokeless Tobacco Council, and the
GothiaTek.RTM. quality standard for snus. Methods for the
manufacture of American type moist snuff and chewing tobacco are
described in e.g. `Wahlberg, I., Ringberger, T. (1999) Smokeless
Tobacco. In: Tobacco: Production, Chemistry and Technology, (eds D.
L. Davis & M. T. Nielsen) pp. 452-460. World Agriculture
Series, Blackwell Science Ltd.
[0059] The smokeless tobacco or non-tobacco snuff composition
according to the present invention may be manufactured according to
the GothiaTek.RTM. standard.
[0060] A second aspect of the present invention is a method for
manufacturing of a smokeless tobacco or non-tobacco snuff
composition for oral use according to the first aspect of the
invention, wherein the method comprises: [0061] a) providing a
tobacco material or non-tobacco plant fibre material; [0062] b)
processing the material provided in step a) and optionally other
ingredients; and [0063] c) optionally packing the smokeless tobacco
or non-tobacco snuff composition, either in pouches, or as is, in
cans, or boxes; wherein lactic acid or a salt thereof is added at
one or more of the following steps: [0064] i) prior to step b),
[0065] ii) during step b), and/or [0066] iii) after step b).
[0067] The processing of the material in step b) may comprise a
heat treatment, such as a pasteurization process.
[0068] In the method according to the present invention the lactic
acid or a salt thereof may be added prior to step b), during step
b), or after step b).
[0069] Prior to the processing of the tobacco material or
non-tobacco plant fiber material in step b) water and possibly
additional additives may be added. During the processing of the
tobacco material or non-tobacco plant fiber material in step b)
water, flavors, sodium carbonate and possibly additional additives
may be added.
EXAMPLES
Example 1
[0070] 3000 g snus was produced in accordance with a modified
version of the GothiaTek.RTM. standard. The method was modified by
omitting the addition of sodium chloride before heat treatment. A
mixture of ground tobacco and water was heat-treated at a
temperature of 100.degree. C. for 2 hours and thereafter at a
declining temperature of from 100.degree. C. to 70.degree. C. for 8
hours, reaching a water content of about 42 wt % of the total
weight of the final composition. After the heat-treatment, the
mixture was chilled to about 20.degree. C. and sodium carbonate was
added to adjust the mixture to an alkaline pH of about 8.3 and
water was added to adjust the water content to about 50 wt % based
on the total weight of the final composition. The resulting base
snus had a water content of 51.2 wt % and a pH value of 8.33. A
bacteria culture, with bacillus bacteria, known to be able to
reproduce in snus environment, was added to the snus base. This
resulted in a bacterial count in the snus base of about log 4.5
CFU/g snus.
[0071] From this snus a 250 g reference sample (NaCl 9%) was
produced by addition of a water solution with sodium chloride to
produce snus with a water content of about 57 wt % based on the
total weight of the final composition and containing 9 wt % NaCl
based on the dry weight of the formulation. This corresponds to a
concentration of NaCl and a water content commonly used in Swedish
type snus. Further, from the same base snus, a second reference
sample (Ref 0%) of 250 g was prepared by addition of water to
obtain a snus with about 57% water content, but containing no added
NaCl. Further, from the same base snus, three 250 g snus samples
were prepared by addition of water solutions with sodium lactate
(NaL) to produce snus with a water content of about 57 wt % based
on the total weight of the final composition and containing 7, 12
and 16 wt % sodium lactate based on the dry weight of the
formulation. The samples are called NaL 7%, NaL 12% and NaL 16%,
respectively.
[0072] All samples were analyzed regarding pH, water content, water
activity (a.sub.w) and bacterial count before they were packed and
stored. The pH and water activity for each sample are presented in
Table 1. The samples were then packed into sealed plastic bags and
transferred to a controlled climate (22.degree. C., 60% RH) where
they were stored for 3 weeks. After 1, 2 and 3 weeks of storage the
samples were analyzed for pH and bacterial count. The pH for all
samples remained above 7.7. The bacterial count results, shown in
FIG. 2, clearly show a bacteriostatic effect of addition of sodium
lactate in snus in all three samples. In general, Swedish snus
products require a water activity of no more than 0.90 to ensure
that no bacterial growth takes place. Samples NaL 7% and NaL 12%
have a water activity of 0.92, as presented in Table 1, which would
suggest strong bacterial growth, but unexpectedly these samples
exhibit a static bacterial count as presented in FIG. 2. This
indicates an antibacterial effect beyond the a.sub.w lowering
effect.
TABLE-US-00001 TABLE 1 Added Added amount Water Sample Salt of salt
(wt %) pH activity (a.sub.w) Ref 0% No 0 8.32 0.93 (reference)
addition Ref 9% NaCl NaCl 9 8.33 0.9 (reference) NaL 7% NaL 7 8.27
0.92 NaL 12% NaL 12 8.23 0.92 NaL 16% NaL 16 8.22 0.9
* * * * *