UNIVERSITY OF CINCINNATI
Date: 10/24/2007_______________
, RobertB. WielanO
^5____________________________________________________5
hereby submit this work as part of the requirements for the degree of:
Master of Science
in:
Chemistry
It is entitled:
Preparation of Calcium Alginate and Calcium Pectinate Films and
Determinations of Their Permeabilities
This work and its defense approved by:
Chair: 47. JamcsO.OlcrC
Di.O/tolO/raiio Or.
Cci/CcliiCar
Preparation of Calcium Alginate and Calcium Pectinate Films and Determinations of
Their Permeabilities
A dissertation to the Graduate School of
the University of Cincinnati in partial fulfillment
of the requirements for the degree of
MASTER OF SCIENCE in the Department of
Chemistry
by
Robert B. Wieland
Bachelors of Science in Chemical Technology University of Cincinnati, June 2001
Committee Chair: Dr. James E. Mar
kABSTRACT
Small amounts of polymers are typically used in flavor and food applications.
Polymers are typically applied in thin coatings which allow for a cost-effective
encapsulation with desirable barrier properties. Understanding the properties of thin
barrier coatings is essential to obtaining optimal encapsulation performance. Many of

the polymers used in the flavor and food industry are cross-linked hydrogels, which
are water insoluble but water swellable. Hydrogel barriers allow water soluble
components to be extracted from the encapsulation system. Flavor components
having a large affinity for water will be extracted from the encapsulation system while
more hydrophobic flavor components will remain encapsulated. Preferential flavor
extraction is a large problem for the flavor industry because flavors are complicated
mixtures of both hydrophilic and hydrophobic components.
Understanding diffusion and permeability coefficients is desirable for creating
optimized encapsulation systems. However, creating thin uniform films reproducibly
can be challenging and expensive. In the past, thick polymer films were cast onto a
metal sheet and cross-linked with the appropriate chemicals. The method produced
wrinkled and inconsistent film thicknesses. The inconsistent films produced
irreproducible diffusion and permeability coefficient data. New testing methods were
developed to understand flavor partitioning across thin hydrogel membranes. One
focus of the present work was to create 10^m to 50^m polymer films reproducibly
with uniform thicknesses. The second focus of this project was to determine thin film
diffusion and permeability coefficients of the created polymer films.
The first portion of this thesis discusses the creation of thin polymer films.
Calciumalginate and calcium pectinate films were created using a lightly scuffed metal
sheet. The sheet was then used in a leveling apparatus which provided a level surface
for film casting. The polymer films were characterized by micrometer measurement,
environmental scanning electron microscopy (ESEM) and swelling ratio experiments.
Micrometer measurements demonstrated the successful preparation of 21 to 23 (+/- 1)
calcium alginate films and 19 to 20 (+/- 1) calcium pectinate films. The 4 to 6% relative
standard deviation was considered acceptable for the present work. The calcium
alginate and calcium pectinate films were also analyzed by ESEM. Both sides of the
films were analyzed at 200X and 1500X magnifications. The polymer film surface
exposed to the scuffed metal sheet produced a rough and irregular surface. The
polymer film surface not exposed to the scuffed metal sheet had a smooth and uniform
surface. Film thickness measurements were also performed using the ESEM computer

software to further verify the film thickness measurements obtained from the
micrometer. The ESEM film thickness measurements demonstrated a 20.9 (+/- 1.1)
calcium alginate film and a 20.2 (+/- 0.7) calcium pectinate film had been produced.
Both films demonstrated an average relative standard deviation of 4 to 6% which was
considered acceptable for the present work. The ESEM measurements of film thickness
demonstrate the methodology for creating thin polymer films is reproducible and within
the desired thickness range. However, the scuffed metal sheet creates films that are
rough on one side and smooth on the other side. Preliminary polymer swelling ratio
experiments in distilled water showed calcium alginate films swell to 2.4 times their
original dry weight and calcium pectinate films swell by a factor of 3.8. The large
swelling ratios for the films indicated that distilled water was an appropriate solvent
for determining film permeability and diffusion coefficients.
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5
The second portion of this thesis focused on determining film diffusion and
permeability coefficients. A new thin-film diffusion cell (TFD) was built and
coupled to a UV/VIS spectrophotometer fitted with a fiber optic probe which
allowed for in-situ measurement of analytes which absorb ultraviolet radiation
such as benzaldehyde. Permeability measurements using benzaldehyde
demonstrated a permeability coefficient of 3X 10-5 cm/sec. (+/- 5%) for the 22
(+/- 1) calcium alginate film and 2 X 10-4 cm/sec. (+/-6%) for the 20 (+/- 1)
calcium pectinate film. Diffusion coefficients were then calculated for the two
films. The diffusion coefficient for a 22 (+/-1) calcium alginate film was 6.5 X
10-8 (+/- 11%) cm2/sec while the diffusion coefficient for a 20 (+/-1) calcium
pectinate film was 3.9 X 10-7 (+/- 12%) cm2/sec. The relative standard
deviations for the permeability and diffusion coefficients were considered
acceptable for this study. The permeability and diffusion coefficients indicated
a calcium pectinate film is more permeable than a calcium alginate film of
equal thickness.ACKNOWLEDGEMENTS
I would like to express my gratitude to Dr. Dave Siegel for the guidance

and support shown to me while obtaining a graduate degree. I
acknowledge my graduate achievement would not have been possible
without the patience, flexibility and understanding shown by this man. I
would also like to thank Dr. Robert Eilerman for his flexibility allowing me to
achieve an academic milestone while maintaining full time duties at the
Givaudan Flavor Corporation.
I would like to acknowledge the financial support of the Givaudan Flavor
Corporation. The financial support allowed for critical glassware to be
purchased and allowed me to obtain a graduate degree.
I would like to give a heartfelt thank you to Dr. Jing Zhang for helping me
understand diffusion and permeability. In this way, Dr. Zhang helped me
become a better chemist with an increased knowledge of polymer
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systems.
I appreciate the guidance Dr. James Mark has given while writing my
graduate thesis and during my academic career. His insight has been
valuable and informative.
I would like to thank my mother Brenda Wilson for her endless
encouragement. Your determination, work ethic and loving support has
enabled me to be successful in the workplace and in academia.
I am grateful for the support and encouragement shown by my wife
Jessica Wieland. Without her support this achievement would not be
possible. Thank you for understanding the extra hours at school and the
extra hours of homework which kept us apart. I could not ask for a more
supportive and inspiring wife.
TABLE OF CONTENTS
LIST OF FIGURES
LIST OF TABLES
7

7
Table 9: Benzaldehyde absorbance measurements across calcium alginate
films 34 Table 10: Benzaldehyde absorbance measurements across
calcium alginate films.3
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8
9. INTRODUCTION
4Both flavors and active ingredients such as vitamins impart important
characteristics to products desirable to consumers in the marketplace.
However, flavors and active ingredients can be lost or degraded during food
processing, with the result of losing consumer benefit. However, critical
components can be encapsulated using polymeric materials to prevent such
losses. Polymers are typically applied in thin coatings which allows for a cost
effective encapsulation with functional properties
1
. Understanding the
properties of thin barrier coatings is essential to obtain optimal encapsulation
performance. The food and flavor industry have used polymeric materials for
decades as bulking agents, viscosifiers, and barrier materials for various
encapsulation systems. Materials such as sugar, maltodextrin, pectin and
alginate can be used to create water soluble encapsulation systems
2
. Pectin
and alginate materials are of great interest to the flavor industry due to the
cross-linkable nature of these natural polymer materials
3
. Cross-linked pectin
and alginate form hydrogel barriers which are water insoluble but water
swellable
4

. The swelling properties of hydrogel barriers can be manipulated by
varying levels of chemical cross-linking along these carbohydrate chains
5
.
Highly cross-linked polymer materials typically demonstrate minimized
diffusion properties which creates an effective barrier reducing flavor loss
during cooking processes. Lightly cross-linked polymers become
less effective barriers due to increased diffusion properties.
Flavor encapsulation systems containing hydrogels have been utilized in food
to create products with increased flavor perception6,7. However, flavors
encapsulated in hydrogel systems typically need to be reformulated to
preserve such a desirable perception. The swelling property of hydrogel
barriers allows flavor components having a large affinity for water to be
extracted from the encapsulation system while more hydrophobic flavor
components remain encapsulated. The swelling property of hydrogel barriers
is a large problem for the flavor industry because flavors are complicated
1 Gutcho, M.H. Microcapsules and Other Capsules. Noyes Data Corporation:
Park Ridge, NJ, 1979.
2 Risch, S.J. (1995). Encapsulation: Overview of Uses and
Techniques. In Risch, S.J. and Reineccius, G.A. (Ed.) Encapsulation
and Controlled Release of Food Ingredients (pp 2-7). Washington, DC:
American Chemical Society.
3 Schlemmor, U. (1989) Studies of the binding of copper, zinc
and calcium to pectin, alginate, carrageenan and gum guar in
HCO"3 - CO2 buffer. Food Chemistry, 32 (3), pg 223-234.
4 Bajpai, S.K.; Sharma, S. (2004) Investigation of swelling/degradation
behavior of alginate beads crosslinked with Ca2+ and Ba + ions.
Reactive & Functional Polymers, 59 (2004), pg 129-140.
5 Flory, P.J. Principles of Polymer Chemistry. Cornell University Press:
Ithaca, NY, 1953.

i
10. INTRODUCTION
mixtures of both hydrophilic and hydrophobic components. For example,
typical fruit flavors contain numerous individual ingredients which impart a
delicate balance and flavor profile. Individual cherry flavor ingredients have
vegetable oil:water partition coefficients ranging from 4 to 1. A partition
coefficient, denoted as P in this document, is the concentration ratio of a
compound in two immiscible solvents at equilibrium8,9. The P coefficient in
this study is a measure of differential compound solubility between vegetable
oil and water. The higher the P value the more hydrophobic the compound.
Since most food applications are exposed to water over time, maintaining a
balanced flavor profile is difficult. Creatin
i
gan encapsulation system with reduced flavor diffusion properties would be beneficial
for the flavor industry.
The flavor industry creates encapsulation systems to address various food processing
issues. Analyzing an encapsulation system typically entails "in-use” tests which only
demonstrate whether or not the encapsulation system provides a benefit
6
. A typical "in-
use” test consists of making an encapsulation containing a flavor. The encapsulated
flavor is then added to a food application and processed under normal cooking
conditions. These tests only provide a result which is negative or positive. Since the
encapsulation system is a complex product no data is provided on what aspect of the
technology is providing the result. Also, the food application is very complex and also
affects how the encapsulation performs. These facts leave the researcher asking
"Have we created a better encapsulation or merely used the encapsulation in a more
desirable environment?”
Analytical experiments, such as encapsulation-dissolution testing, have been created
to characterize the individual encapsulation systems in model food application

environments. Valuable data has thus been obtained which can predict encapsulation
performance in various applications
7
. However, encapsulation performance is highly
dependent on capsule particle size, polymer barrier thickness, polymer permeability,
capsule structure and encapsulation makeup. Capsule performance is measured, with
account for all the variables that affect encapsulation performance.Previously at the
Givaudan Flavor Corporation attempts were made to study the diffusion and
permeability properties of hydrogel films containing clay
8
. Films approximately 25 to
200 microns were cast and cross-linked with the appropriate reagents. The method
produced wrinkled films and inconsistent film thicknesses that only allowed for small
pieces of the films to be analyzed. The irregular films produced irreproducible diffusion
6 Mark, J.E.; Allcock, H.R.; West, R. Inorganic Polymers. 2nd ed. Oxford University
Press: New York, NY, 2005.
7 Martin, C.A., (2003) Evaluating the Utility of Fiber Optic Analysis for Dissolution
Testing of Drug Products. Dissolution Technologies, pg 37-39.
8 Vale, J.M. (2004). Modification of Calcium Alginate Membranes with
Montmorillonite Clay to Alter the Diffusion Coefficient (Masters Thesis, University of
Cincinnati, Department of Chemistry, 2004).
11
11
and permeability measurements. The analytical methodology used to characterize the
films was tedious and involved the use of multiple analytical techniques. Each
analytical technique contributed compounded errors which affected the accuracy of the
data.
The primary goal of the present study is to create thin hydrogel films whose diffusion
and permeability properties can be measured easily with relative accuracy.
Understanding flavor diffusion across thin hydrogel membranes will provide the

basic knowledge for hydrogel encapsulation development. The films created were
approximately 20^m thick, which replicates typical coating thicknesses used in the
flavor industry. Creating thin films can be challenging due to the following
circumstances: thin films become very brittle, brittle and cracked films lead to
ineffective barriers, and thin films are hard to cast uniformly. The thin films created
were uniform and reproducible which ensured a robust method and reliable data.
For the present work, two calcium cross-linkable polymers were chosen for study.
Alginate and pectin were chosen for their acceptance in the food and flavor industry.
The thin film hydrogels were characterized by micrometer film thickness
measurements, Environmental Scanning Electron Microscope (ESEM), swelling
ratio
experiments and Thin Film Diffusion (TFD) - Ultraviolet-Visible (UV/VIS) analysis.
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1.1 Pectin: Sourcing, Manufacture and Functionality
Pectin and cellulose are abundant in fruits such as oranges, lemons, limes and
apples. Pectin and cellulose associate creating a macromolecule called protopectin
which binds or absorbs water. Cellulose provides mechanical rigidity and pectin
provides flexibility in the fruit and plant stock. The mechanical properties of
protopectin allow the plant to weather environmental changes during seasonal
changes
9
.
Large farming ventures and food companies process fruits such as oranges and
apples, thus creating waste streams of citrus peel and apple pomace. The waste
streams are typically created in the regional areas where the crop is grown. For
instance, large waste streams of orange peel are created in Mexico, California and
Florida. The waste streams are collected and processed to yield valuable extracts
such as pectin and cellulose.
Pectin is produced worldwide by major manufacturing companies such as Cargill

and CP Kelco. Extraction techniques performed on the citrus peel and apple
pomace can be altered to produce pectin with different functionalities. Typically, the
citrus peel or apple pomace is added to a hot acid solution where the protopectin
undergoes hydrolysis. The hydrolysis step liberates the pectin from the cellulose.
9
www.cargilltexturizing.com/products/hydrocolloids/pectins/cts_prod_hydro_pec_fun.sht
ml
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The citrus peel or apple pomace is then separated from the hot acid solution by
pressing, filtration and concentration processes. The concentrated solution is added
to ethanol where the pectin precipitates. This precipitate is then washed, dried, and
milled to a
specific particle size. Processing conditions are constantly being modified and
optimized to meet specific customer needs
10
.
Citrus peel and apple pommace processing allows for three types of pectin to be
manufactured. The hydrolysis processing step applied to citrus peel and apple
pomace alters the degree of esterification (DE) found in the pectin. Thermodynamic
properties such as glass transition temperature (Tg), melting point (Tm) and setting
rates can be drastically altered by the degree of esterification. Pectin with a DE value
greater than 50 is referred to as high-methoxyl pectin (HM)15,16. Typical HM-
pectin’s have a 55-85% degree of esterification and form thermostable gels in acidic
pH solutions containing 60% sugar. HM-pectin is used to stabilize milk by reducing
protein flocculation and enhancing beverage viscosities. High-methoxyl pectin has
other valuable uses such as minimizing ice crystal formation, thus enhancing
confectionary freeze-thaw properties. Pectin with a DE value below 50 is referred to
as low-methoxyl pectin (LM). Typical LM-pectin’s have a 15-45% degree of
10

www.cargilltexturizing.com/products/hydrocolloids/pectins/cts_prod_hydro_pec_man.s
html
14
14
esterification and form thermoreversible gels under acidic or basic processing
conditions. Thixotropic solutions for ice cream can be created using LM-pectin. LM-
pectin also has the ability to be crosslinked by divalent cations such as calcium and
magnesium. Crosslinked pectin typically becomes water insoluble and is useful for
film and encapsulation purposes. This pectin can also be extracted under basic
conditions using ammonia producing amidated low methoxyl pectin (LMA). Typical
LMA-pectin’s have a 15-45% degree of esterification and a 5-25% degree of
amidation (DA). The addition of the amide groups to the pectin molecule changes
the rheological properties and reduces pectin’s ability to be crosslinked by divalent
cations. LMA-pectin produces thermoreversible gels which are typically used in
glazes and fruit preparations. Many different forms of pectin can be created to meet
specific customer needs. The variety of pectin’s produced allows for new and
innovative consumer products to be developed.
1.2 Pectin: Structure
Pectin is a natural polysaccharide containing up to1000 saccharide units in a chain-
like configuration. Pectin molecules have a linear backbone composed of units of (1,
4)-linked a-D-galacturonic acid and its methyl ester
11
. Figure1.2-1 illustrates the
basic structure of a pectin molecule.
11 www.cpkelco.com/food/pectin.html
15
15
Methyl ester form of galacturonic acid
Figure 1.2-1: Structure of the pectin molecule.
The galacturonic acid units may be in the salt form (galacturonate), which allows the

pectin to be an anionic polymer. The galacturonic acid residues can be esterified
with methanol. When 50% or more of the carboxyl groups contained in the polymer
are methylated the pectin is considered high-methoxyl pectin. This pectin is not
cross-linkable with divalent cations and has limited uses for flavor encapsulation
systems. Less than 50% methylation produces pectin which is cross-linkable with
divalent cations such as calcium. Figure1.2-2 illustrates the basic structure of a
calcium pectin molecule. The pectin structure also contains L-rhamnose and
methylpentose. The addition of these sugars to the pectin polymer structure creates
a branched molecule which has much reduced linearity. The average molecular
weight of pectin is typically 50,000 to 150,000 g/mol.
1.3 Alginate:
Sourcing,
Manufacture and
Functionality
Seaweed has
been used to
obtain natural
polymers such
16
16
as alginate, agar and carrageenan over the last 50 years. Alginate provides rigidity
for the seaweed plant by association with sodium chloride in ocean water. Alginate
also acts as a humectant to reduce water loss in the plant in changing tidal
conditions
12
. Alginate is found in the Phaeophycaea brown algae family. Seaweed
varieties such as Macrocystis pyrifera, Ascophyllum Nodosum and Laminaria are
useful for alginate production
12
. Comercially important seaweed is typically

harvested in the coastal waters of California, Australia, Norway and Japan.
Seaweed from different coastal regions produces alginate with different properties
due to structural differences in the extracted polymer.
The manufacturing process to obtain alginate begins with harvesting seaweed in the
desired coastal region. Boats are built to a special design to skim the ocean surface
and retrieve the top three feet of the seaweed plant. The harvested seaweed is gently
dried and milled to desired specifications for optimal processing. The milled seaweed is
then added to hot water and sodium carbonate under mixing conditions. The caustic
treatment allows the seaweed to swell and form a viscous solution. The highly viscous
solution is diluted and the insoluble residues are removed. Chlorine is added to the
liquid fraction containing the alginate and treated with calcium chloride to form a water
insoluble precipitate. The calcium alginate is then recovered, pressed to remove
excess water and treated with a hydrochloric acid solution. The acid-washed alginate
cake is then pressed and washed with a basic solution to produce sodium alginate
which is water soluble. The solubilized alginate is then spray dried and sieved to the
desired customer specifications20,21
12 Cosgrove, D.J., (2005) Growth of the plant cell wall. Molecular Cell Biology, 5,
pg 850-861.
12
www.cargilltexturizing.com/products/hydrocolloids/alginates/cts_prod_hydro_alg_raw.s
html.
17
17
.Alginate is generally used as a cold-setting gel that is thermally stable when
crosslinked. The food industry typically uses alginate as a viscosity control agent for
products such as jellies, jams, pastes, beverages, soups and ice-cream22,23,24.
Industries such as pharmaceutical and biomedicine companies use alginate to
encapsulate drugs and cellular materials
13
. Alginate has also been used to dehydrate

products such as paper and textiles, as flame retardants for fabrics, and as blood
detoxifiers.
1.4 Alginate: Structure
Alginate is a complex carbohydrate comprised of glucuronic and mannuronic acid
monomers. Based on the seaweed source and processing, alginate can be
produced with varying glucuronic and mannuronic acid contents
14
. Figure 1.4-1
illustrates the monomers contained in alginate.
Alginates containing large
percentages of glucuronic
acid content are called
high-G
alginates
15
. High-G alginates typically produce gels that are strong and exhibit good
heat stability. However, the gels are brittle and this can create a product with little
impact strength. Alginates containing large percentages of mannuronic acid content
are called high-M alginates. These alginates produce gels that are elastic, and this
increases freeze-thaw stability. The block sequences of glucuronic acid and
mannuronic acid monomer units also affect alginate functionality. Varying block
lengths such as GG, MG and MM produce gels with blended properties and regimes
13 Milanovanovic, A.; Bozic, N. and Vujcic Z. (2007) Cell wall invertase
immobilization within calcium alginate beads. Food Chemistry, 104 (1), pg 81-86.
14
www.cargilltexturizing.com/products/hydrocolloids/alginates/cts_prod_hydro_alg_mo
l.shtml.
15 Sime, Wilma J., (1990J Alginates Limewood, Raunds, Northhamptonshire NN9
6NG, UK p 53-60.
18

18
(1,4) P — D mannuronate (1,4) a—Lguluronate
Figure 1.4-1: Alginate monomers.
of localized crystallization when glucuronic acid units are crosslinked with divalent
cations
16
. Figure 1.4-2 illustrates alginate glucuronic and mannuronic block types.
Figure 1.4-2: Alginate
block types.
The divalent cation fits into the D-glucuronic acid block structure like eggs in an egg
box. This binds the alginate polymers together by forming junction zones which
results in gelation
17
. Figure 1.4-3 illustrates the calcium binding site of D-glucuronate
and Figure 1.4-4 illustrates the egg box structure of calcium crosslinked alginate.
16
www.fmcbioploymer.com/food/ingredients/Alginates/PGA/Introduction/tabid/2410/fau
lt/aspx.
17
www.fmcbioploymer.com/food/ingredients/Alginates/PGA/Introduction/tabid/2412/fault/a
spx.
19
19
DOST
Guluronate block
-QOC
Mannuronate block
Mannuronate-Guluronate-Mannuronate block
Figure 1.4-3: Calcium binding site in polyguluronate dimer.
Figure 1.4-4: Calcium alginate cross- linked "Egg box” model.

2. Experimental Section
2.1 Experimental Objectives
The objectives of the present work are as follows:
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Prepare uniform films of calcium alginate reproducibly in a 5 to 50pmthickness range.
a) Prepare uniform films of calcium pectinate reproducibly in a 5 to 50^m
thickness range.
b) Analytically measure the diffusion of benzaldehyde across the
hydrogel barriers to determine permeability and diffusion coefficients
2.2 Raw Materials
1. Sodium alginate extracted from brown seaweed (Phaeophyceae) was chosen
to create thin films. The sodium alginate is cross-linkable with divalent cations
such as Ca and Mg2+2+. The material is a whitish tan powder containing 1 to
3% moisture. The average molecular weight is 75,000 g/mol. The sodium
alginate trade name is Keltone LV and was supplied by ISP (International
Specialty Products) 1361 Alps Road, Wayne, New Jersey 07470.
2. Pectin extracted from lemon peel was chosen to create additional thin films.
The pectin is also cross-linkable with divalent cations such as Ca2+ and
Mg2+. The material is a white powder containing approximately 3 to 4%
moisture and average molecular weight was 95,000 g/mol. The pectin trade
name is TIC Gum-32 and was supplied by TIC Gums, 4609 Richlynn Drive,
Belcamp, MD 21017
21
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3. Calcium chloride was used as the crosslinking material for sodium alginate
and pectin. The material is a white granular powder containing approximately
2% moisture. The calcium chloride was supplied by the Givaudan Flavor
Corporation, 1199 Edison Drive, Cincinnati, Ohio 45126. .
4. Benzaldehyde was used to measure diffusion across the calcium alginate and

calcium pectin films. The benzaldehyde was 98% pure with a boiling point of
435.1 K. Benzaldehyde has a Log P value of 1.78 which is considered to be
relatively water soluble in the flavor industry. The benzaldehyde was supplied
by the Givaudan Flavor Corporation, 1199 Edison Drive, Cincinnati, Ohio
45126
5. Miglyol 812 (Medium chain
triglycerides) was used to prepare
dilute benzaldehyde solutions. It is
an oxidative-stable vegetable oil
which was supplied by Givaudan Flavor Corporation 1199 Edison Drive,
Cincinnati, Ohio 45126.
22
22
Figure 2.2-1: Structure of benzaldehyde.
2.3 Procedures - Laboratory Testing Equipment Preparation
2.3.1 Film Sheet Preparation
Three Baker’s Secret medium cookie sheets were purchased from a local grocery
store. The measurements of the cookie sheets were 43.2cm X 27.9cm X 1.9cm with
an estimated surface area of 1205.3 cm2. The cookie sheets were lightly scuffed
under water with an abrasive sponge to partially remove the Teflon™ coating from
the sheets. Partially removing the Teflon™ coating allowed the polymer solutions to
wet the surface creating a uniform polymer film.
2.3.2 Leveling
Film Sheet Apparatus
A leveling apparatus
was created to
ensure a level
surface for use with
the film sheets. The leveling apparatus was created using medium-density
fiberboard and spring-loaded clamps. The base measurements of the leveling

apparatus were 96.5 cm X 63.5 cm X 2.0 cm. The clamping system consisted of two
pieces of 86.4 cm fiberboard strips attached to the base of the leveling apparatus
43.5 cm apart. Three spring-loaded clamps were applied to each strip at the desired
23
23
Figure 2.3.1-1: Scuffed cookie sheet.
distance to ensure three film trays could be clamped to the apparatus. The leveling
apparatus was then stored in a fume hood and adjusted with shims to ensure a level
surface.
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24
« 1
i t
Figure 2.3.2-2:
Leveling film
apparatus containing film sheets. 2.4 Procedures - Sample Preparation
2.4.1 Creating 1.0% Sodium Alginate Solutions
Approximately 990.0g of distilled water (pH 6.5) was added to a 2000mL Waring
blender and mixed using a Cole-Parmer solid state power controller set to 30%
25
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