miina härma gümnaasium - Õpetaja erkki...in juice drinks, the amounts of sugar and ph values were...

Miina Härma Gümnaasium

Mirjam Lätt

Chemistry

Comparison of Homemade and Manufactured Cranberry Juices Available in Estonia

Extended Essay

Supervisor: Erkki Tempel

Candidate Session Number: 006552-0010

Number of words: 3907

Tartu 2013

Mirjam Lätt 006552-0010

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Abstract (word count: 299)

Balanced nutrition plays very important role in our chances to have a long healthy life. Our

knowledge of healthy and unhealthy components in our food is not sufficient and needs to be

increased.

In this extended essay I decided to investigate how pH-level, sugar and vitamin C

concentration differ between manufactured and homemade cranberry juice available in

Estonia.

I compared vitamin C concentration, pH level, and sugar content of 5 different cranberry

juices and juice drinks.

Vitamin C content was measured by titration using iodine compounds and starch. I

determined how much KIO3 was needed to oxidize all vitamin C in solution, after what the

solution become bluish.

I have measured the pH content of all drinks with pH meter. Also, I have measured the

glucose content of all drinks measuring the mass of standard sugar solutions with 5, 10 and

15 ml sugar content, calculating solutions´ density and creating a graph from results. I have

found the amount of sugar in juice solutions using the graph of standard solutions.

The content of raw homemade cranberry juice and ecologically produced pasteurized

cranberry juice was similar in terms of vitamin C and sugar content and pH value. This can

be explained with well selected manufacturing techniques of ecological juice, what helps to

preserve all valuable contents of raw cranberries.

In juice drinks, the amounts of sugar and pH values were also quite similar to the homemade

and ecologically produced juice. As cranberry juice content in these drinks is according to the

product label 10-12%, the results can be explained only with sugar and acidity regulators

added to these drinks. However, I could not detect any vitamin C in any of these juice drinks

at all. It means that juice drinks are not healthy products although majority of people think

otherwise.


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Table of Contents

Abstract (word count: 299) 2

Table of Contents 3

1. Introduction 4

2.Research question 5

3. Background information 5

3.1 Selection of topic 5

3.2 Ascorbic acid 6

3.3 Carbohydrates 7

3.4 pH 9

4. Method 10

4.1 Measuring vitamin C concentration by titration 10

4.1.1 Calculating vitamin c concentration in homemade juice 12

4.1.2 Calculating vitamin c concentration in ecological juice 13

4.2 Sugar Level 14

5. Evaluation-problems/improvements 18

6. Conclusions 18

7. Bibliography 22

8. Appendix 1 24

9. Appendix 2 25


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1. Introduction

Food chemistry is an exciting topic to me, as I am interested in healthy nutrition problems.

Knowing the chemical content of foods lets us exactly to know what vitamins and other

ingredients we are obtaining from our food, and what is lacking.

The topic I am interested in is the carbohydrate content in different foods.

Carbohydrate ingredients are commonly added to processed foods to control flavour, texture,

and other functional properties (Bartosz, 2014, p. 67).

Although energy obtained from carbohydrates is necessary to our body, we do not think quite

often that sugar in sodas and lemonades, different sweets, sugar added to coffee and tea, are

all carbohydrates, so it might end up with excessive carbohydrate consumption.

Second topic chosen what is exciting to me, is vitamins. It is well known that for effective

functioning our body also needs vitamins. We are obtaining vitamins from our everyday

food, so again the chemical content of food is a subject to investigate.

I decided to investigate cranberry juice and juice drinks as source for ascorbic acid and

carbohydrates, because cranberry is local fruit, can be easily preserved for a long time and

can therefore be a significant source of vitamin C in Estonia. Also cranberry is growing wild

so it can be picked without any additional cost. Cranberries are considered useful and healthy

local berries, so people who buy these juices and juice drinks can think quite easily that they

are consuming a healthy product.

In addition I decided to investigate pH levels of these juices to find out how acidity differs

between 100% juice and juice drinks with 10% of juice content.


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2.Research question

How do pH-level, sugar and c-vitamin concentration differ between manufactured and

homemade cranberry juice available in Estonia?

3. Background information

3.1 Selection of topic

An overall healthy diet does not only give you the energy and nutrition you need but grants

health benefits as well. Healthy diet is a great source for minerals and vitamins what is

essential to live well and fight diseases.

As I am interested in healthy diet, C vitamin content in Estonian food is an interesting topic

to me.

C vitamin is widely distributed in fresh fruits and vegetables (Barros, 2014, p. 61).

Due to our geographical location we do not have fresh fruit of our own in winter time. Fresh

fruit from southern countries is available in our shops, but due to the prices it is not

affordable for people with low, and sometimes even with medium income. Also the

knowledge and habits of healthy nutrition are not essential to all people.

A research project conducted among Estonian children in age group 11-15 years showed that

daily consumed fruits only 36% of children (Maser et al, 2009). Nutrition habits and pattern

of children are mainly based on those of their parents.

According to nutrition research the amount of overweight children in Estonia has been

increasing significantly during last years (Maser et al, 2009).

Overweight and obesity may increase the risk of many health problems, including diabetes,

heart disease, and certain cancers. (NIDDK, 05.07.2013)

In my family there has always been an understanding that lemonade and sodas are not healthy


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drinks. Instead we were offered a lot of juice and juice drinks. My parents were of opinion

that there drinks were more useful as they were containing natural ingredients and vitamins.

As there have been lately quite a lot of discussions about real content of juice drinks, I have

also started to think about the content of these so-called healthy drinks.

3.2 Ascorbic acid

Scheme 1. Vitamin C (ascorbic acid) (Fyhle et al, 2013, p. 795).

Ascorbic acid falls within the class of enolic lactones of glyculosonic acids. The most

important member of this class is L-ascorbic acid. (Addy et al, p.200) L-ascorbic acid

(C6H8O6) is the trivial name of Vitamin C. The chemical name is 2-oxo-L-threo-hexono-1,4-

lactone-2,3-enediol (Naidu, 2003).

L-ascorbic acid is a co-factor for hydroxylases and monooxygenase enzymes involved in the

synthesis of collagen, carnitine and neurotransmitters. Humans cannot synthesize ascorbic

acid (Naidu, 2003) themselves.

Being a water soluble compound C vitamin is easily absorbed but it is not stored in the body

(Naidu, 2003).

The average daily intake level that is sufficient to meet the nutritional requirement of

ascorbic acid or recommended dietary allowances (RDA) for adults (>19 yr.) are 90 mg/day

for men and 75 mg/day for women (Naidu, 2003).


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The stability of ascorbic acid decreases with increase in temperature and pH. This destruction

by oxidation is a serious problem in that a considerable quantity of the vitamin C contents of

food is lost during processing, storage and preparation. Ascorbic acid decreases gradually

during storage especially at temperature above 0°C (Oyetade et al, 2012).

Ascorbic acid is reversibly oxidized to dehydroascorbic acid. Further oxidation of

dehydroascorbic acid leads to the irreversible formation of 2,3-diketogulonic acid.

Scheme 2. Oxidation of L-ascorbic acid to dehydroascorbic acid (Bartosz, 2014, p. 62).

3.3 Carbohydrates

The group of compounds known as carbohydrates received their general name because of

early observations that they often have the formula Cx(H2O)y—that is, they appear to be

“hydrates of carbon”. Carbohydrates are usually defined as polyhydroxy aldehydes and

ketones or substances that hydrolyze to yield polyhydroxy aldehydes and ketones (Fyhle et

al, 2013, p. 980).

The simplest carbohydrates, those that cannot be hydrolyzed into simpler carbohydrates, are

called monosaccharides. Carbohydrates that undergo hydrolysis to produce only 2 molecules

of monosaccharide are called disaccharides (Fyhle et al, 2013, p. 980).

Carbohydrates appear in the diet as either polysaccharides of 2 to 1000 monosaccharide units

or as simple monosaccharide sugars (Bartosz, 2014, p. 57).


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Carbohydrates are synthesized in green plants by photosynthesis—a process that uses solar

energy to reduce carbon dioxide. The overall equation for photosynthesis can be written as

follows:

x CO2 + y H2O + solar energy: Cx(H2O)y + x O2

Carbohydrate

(Fyhle et al, 2013, p. 981).

Nearly all carbohydrates, such as sucrose (normal table sugar), taste sweet, and are critical to

our perception and enjoyment of the foods that we eat. Carbohydrates also serve as stores of

chemical energy in our bodies, determine our blood type, and in plants can be united to make

important fibers like cellulose and amylose (Fyhle et al, 2013, p. 979).

Ordinary table sugar is a disaccharide called sucrose. Sucrose, the most widely occurring

disaccharide, is found in all photosynthetic plants and is obtained commercially from

sugarcane or sugar beets. Sucrose has the molecular formula C12H22O11. Hydrolysis of 1 mol

of sucrose yields 1 mol of d-glucose and 1 mol of d-fructose.

Not all carbohydrates are called sugars. Sugar is a term what is used when talking about

sucrose, but also about other water soluble mono- and disaccharides with sweet taste (Eger

Ninn, 04.05.2012)


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Scheme 3. Sucrose (Fyhle et al, 2013, p.1006).

It is considered that consumption of white sugar should not exceed more than 10% of daily

energetic needs. Our body needs daily different carbohydrates, including fibers (Maser et al,

2009).

3.4 pH

pH is the standard measure of how acidic or alkaline a solution is. It is measured on a scale

from 0 – 14. pH of 7 is neutral, pH less than 7 is acidic, and pH greater than 7 is basic. The

closer pH gets to 1, the more acidic. The closer pH gets to 14, the more basic.

The pH scale is logarithmic, which means that a unit decrease in pH equals a ten fold

increase in acidity.

Hydrogen (H+) ions control acidity levels. pH measures the concentration of H+ ions (Addy et

al, 2004).


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Following juices and juice drinks have been used for this experiment:

1. Homemade raw cranberry juice

2. Cold press ecological cranberry juice, pasteurized

3. Aura cranberry drink, contains at least 10% cranberry juice, carbohydrates 9,1 g/100 ml

4. Gutta cranberry drink, contains 10% cranberry juice, carbohydrates 11 g/100 ml

5. Põltsamaa cranberry drink, contains 12% cranberry juice, carbohydrates 10,6 g/100 ml,

from what sugar 10 mg

4. Method

4.1 Measuring vitamin C concentration by titration

Vitamin C content was measured by redox titration using iodate solution and starch. I

determined how much KIO3 was needed to oxidize all vitamin C in solution, after what the

solution become blue due to the ability of excess I2 to change the colour of starch into blue.

When iodate ions (IO3−) are added to an acidic solution containing iodide ions (I−), an

oxidation-reduction reaction occurs.

IO3-+5I- + 6H+ = 3I2 +3H2O

It is the iodine formed by this reaction that oxidises the ascorbic acid to dehydroascorbic acid

as the iodine is reduced to iodide ions.

ascorbic acid + I2 → 2 I− + dehydroascorbic acid

Due to this reaction the iodine formed is immediately reduced to iodide as long as there is

any ascorbic acid present. Once all the ascorbic acid has been oxidised, the excess iodine is

free to react with the starch indicator, forming the blue-black starch-iodine complex. This is

the endpoint of the titration.

Equipment needed to determine vitamin c concentration:


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• 5 different juices

• 0.002 mol/dm3 KIO3 solution

• 10% KI solution

• 0.1 mol/dm3 HCl solution

• 0.5% (C6H12O6)n solution

• 25.0 cm3 pipette ± 0.1 cm3

• 50.0 cm3 burette and stand ± 0.1 cm3

• 250 cm3 volumetric flask ± 0.1 cm3

• conical flask and funnel

I found out how much, in volume, hydrochloric acid it took to neutralize the sodium

carbonate as follows:

• Burette was filled with KIO3 solution.

• Pipette was filled up to 25 cm3 juice that was placed into a conical flask. 5 ml of 10%

KI solution, 50 ml HCl and 3 ml (C6H12O6)n were added to the solution and the conical flask

was placed directly under the burette. The solution in the flask was red.

The tap of burette was opened. KIO3 was let to titrate drop by drop. The notes were taken of

how much KIO3 were needed to make the solution from red to blue.

The experiment was repeated three times and results were recorded. The same was done with

the rest of the juices (Determination of Vitamin C Concentration by Titration). Titration

results are provided in Table 1.

Table 1. Titration results

Juice Titration I

± 0.05 cm3

Titration II

± 0.05 cm3

Titration III

± 0.05 cm3

Average titration

± 0.05 cm3

Homemade 3.7 cm3 3.5 cm3 3.6 cm3 3.6 cm3

Aura no colour

change

no colour

change

no colour

change

-

Ecological 3.2 cm3 3.2 cm3 3.2cm3 3.2 cm3

Põltsamaa no colour

change

no colour

change

no colour

change

-


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Gutta no colour

change

no colour

change

no colour

change

-

4.1.1 Calculating vitamin c concentration in homemade juice

Initial data

M (C6H8O6) = 176 g/mol

V2 ((C6H12O6)n) = 3 ml ± 0.05 ml

p ((C6H12O6)n) = 0.5%

c (KIO3) = 0.002 mol/dm3

c (HCl) = 0.1 mol/dm3

L1V1 (homemade) = 25 ml ± 0.05 ml

V3 (KI) = 5ml ± 0.05 ml

p3 = 10%

Reactions to consider

1.) IO3- +5I- + 6H+ = 3I2 +3H2O

2.) C6H8O6 + I2 =2I- + C6H6O6 + 2H+

0.002 mol KIO3 - 1000 cm3

z – 3.6 cm3

Z = 0.002 x 3.6/1000

Z = 0.0000072 mol KIO3 was used to oxidise ascorbic acid

As a result of reaction 1, we will have 3 moles of I2, originating from 1 mole of KIO3

0.0000072-1 mole

y-3

y=0.0000216 mol (I2)


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According to reaction 2, 1 mole of I2 is used to oxidise 1 mole of C6H8O6

Ratio is 1:1, therefore n (C6H8O6) = 0.0000216 mol

𝑐 = !! => c = 0.0000216/0.025 = 0.0008642 M

𝑛 = !!

=> m = 0.0000216*176 = 0. 0038016g = 3.8016mg/25ml

The amount of vitamin C in 25 ml of homemade juice is 3.8016 mg

3.8016 - 25 ml

X2 - 100 ml

X2= 15.2064 mg/100ml

The amount of vitamin C in homemade juice is 15.2064 mg/100 ml

4.1.2 Calculating vitamin c concentration in ecological juice

Initial data

M (C6H8O6) = 176 g/mol

V2 ((C6H12O6)n) = 3ml ± 0.05 ml

p ((C6H12O6)n) = 0.5%

c (KIO3) = 0.002 mol/dm3

c (HCl) = 0.1 mol/dm3

L1V1 (ecological) = 25 ml ± 0.05 ml

V3 (KI) = 5ml ± 0.05 ml

p3 = 10%

Reactions to consider

1.) IO3- +5I- + 6H+ = 3I2 +3H2O

2.) C6H8O6 + I2 =2I- + C6H6O6 + 2H+


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0.002 mol KIO3 - 1000 cm3

z – 3.2 cm3

Z = 0.002 x 3.2/1000

Z = 0.0000064 mol KIO3 was used to oxidise ascorbic acid

As a result of reaction 1, we will have 3 moles of I2 from 1 mole of KIO3

0.0000064-1 mole

y-3

y=0.0000192 mol (I2)

According to reaction 2, 1 mole of I2 is used to oxidize 1 mole of C6H8O6

Ratio is 1:1, therefore n (C6H8O6) = 0.0000192 mol

𝑐 = !!=> c=0.0000192/0.025=0.000768 M

𝑛 = !!

=> m=0.0000192*176=0. 0033792g =3.3792mg/25ml

The amount of vitamin C in 25 ml of ecological juice is 3.3792mg

3.3792 - 25 ml

X2 - 100 ml

X2= 13.5168 mg/100ml

The amount of vitamin C in ecological juice is 13.5168 mg/100ml

4.2 Sugar Level

Sugar amount in investigated juices and juice drinks was evaluated using standardized sugar

solutions.

The procedure was carried out as follows:


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1. 5 mL of sugar and 45 mL of water were poured into a small beaker. (Water was added so

that the volume of total solution was 50 mL).

2. Solution was stirred until the sugar was dissolved.

3. The beaker was weighed and the dry weight (the weight of the beaker) was subtracted to

determine the mass of the solution.

4. The density was determined by using the formula 𝜌 = !!

(density equals mass divided by

volume).

5. The procedure above was repeated by using 10 mL of sugar and 40mL of water, and again

using 15 mL of sugar and 35 mL of water. (Water was still added so that the volume of total

solution was 50 mL).

6. Density for 5, 10 and 15 mL of sugar solutions was determined by using the formula

𝜌 = !!

. Amount and mass of sugar, mass and density of solutions are presented in Table 2.

7. Results were graphed (the density vs. the amount of sugar). The graph is presented in

Appendix 1, Graph 3.

8. 50 mL of each investigated drink was measured into beakers.

9. The beaker was weighed and the dry weight (the weight of the beaker) was subtracted to

determine the mass of the drinks.

10. The density of drinks was determined by using the formula 𝜌 = !!

.

11. Using the sugar solution volume/density ratio standard graph completed before, the

amount of sugar in the investigated drinks was determined (University of Canterbury, n.d.).

Mass of sugar was calculated using the amounts found from the graph. Mass calculation from

graph is shown in Appendix 1, Graph 4. The results of this experiment are presented in Table

3. Comparison of results is also presented on Graph 1.

Table 2. Mass of Sugar, Standard Sugar Solution 50 ml

Amount of sugar

(ml) ± 0.05ml

Mass of solution

(g) ± 0.01g

Density of solution

(g/cm3)

Mass of sugar (g) ±

0.01g

5 51,28 1,026 4,26

10 53,58 1,07 8,53

15 55,85 1,117 12, 81


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Table 3. Mass of Sugar, Investigated Juices

Juice Mass of

50 ml

juice (g)

± 0.01g

Density of

juice

calculated

Amount

of sugar

(ml)

Mass of

sugar (g)

± 0.01g

Mass of sugar

in 100 ml (g) ± 0.01g

Homemade 51.74 1.035 6 5,11 10,22

Ecological

juice

51.79 1.036 6,1 5,2 10,4

Põltsamaa 51.95 1.039 6,3 5,37 10,74

Gutta 52.18 1,044 7 5,96 11,92

Aura 51.54 1,03 5,3 4,52 9,04

Graph 1: Comparison of sugar mass in 100 g of drink

4.3 pH

PH was measured in each juice separately with Vernier pH-meter, so that the sensor was


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placed into juice and the results were recorded from the Vernier LabQuest that was

connected with the Vernier pH sensor. The results are presented in Table 4 and on Graph 2.

Table 4: pH Values of investigated Juices.

Juice pH

Home made 2.36

Ecological juice 2.43

Põltsamaa 3.06

Gutta 2.71

Aura 2.76

Graph 2: Comparison of pH values

The results of all 3 experiments on all 5 investigated drinks are presented in Table 5.

Table 5. Summarised Results of Experiments conducted.

Juice Content of vitamin pH Mass of sugar in


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C in 100 ml (mg) 100 ml (g)

± 0.01g

Home made 15,2 2.36 10,22

Ecological

juice

13,52 2.43 10,4

Põltsamaa - 3.06 10,74

Gutta - 2.71 11,92

Aura - 2.76 9,04

5. Evaluation-problems/improvements

There is always a possibility for random errors in experiments. For example human eyes

cannot see the exact values.

It was quite difficult to notice exact moment of colour change during titration, as the solution

did not become blue, but purple. This happened due to red colour of the initial solution for

titration. Therefore the exact amount of KIO3 used for titration can be incorrect.

Measuring of amounts of juices investigated and reagents used could also cause errors during

titration process.

Also, as glucose content was evaluated via indirect method, it could cause errors. The sources

of potential deviations are: incorrect measurements of amounts of investigated solutions,

incorrect assessments of the weight of solutions. Drawing graph and evaluating volume from

standard graph drawn can also cause deviations from proper measurements, as volume

evaluation was done manually and manual drawings are not fully exact.

6. Conclusions

The aim of this work was to evaluate the content of different cranberry juices available in

Estonia in terms of vitamin C level, sugar content and pH value.

Vitamin C concentration was evaluated by titration. It was found out that homemade raw


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cranberry juice and ecologically produced cranberry juice were the only juices which

contained vitamin C, both in quite similar amounts. The amount of vitamin C in homemade

juice was slightly higher compared to the amount in ecologically produced juice.

During manufacturing ecologically produced cranberry juice was pasteurized, what means

that it was exposed to heat at temperature ranging from 60 to 90°C only for short time period

(United States Department of Agriculture, Agricultural Research Service, n.d.). Such

manufacturing process has not destroyed vitamin C in this juice. As pointed out before, time

of heating and maximal heat are very important factors connected with vitamin C stability.

All manufactured juice drinks did not contain vitamin C at all. This can be explained by the

fact that vitamin C is sensitive to heat and was probably fully destroyed during repeated

heating in manufacturing process.

PH levels of juices and juice drinks were measured with pH-meter. The pH level of all

investigated juices and drinks was quite similar, ranging from 2,36 (raw homemade juice) to

3,06 (Põltsamaa juice drink). It was quite surprising that all juice drinks had also pH level

close to natural and ecological juice, as natural juice content in these drinks is only 10-12%.

After further investigations of juice drink ingredient lists it was found that citric acid as

acidity regulator has been added to all 3 investigated juice drinks in order to obtain pH level

similar to cranberry juice.

Carbohydrate levels were measured using standardized sugar solutions. Carbohydrate levels

were also relatively similar, ranging from 9,4mg/100 ml to 11,94mg/100 ml.

The similar carbohydrate levels in juice drinks and 100% juice can be explained with added

carbohydrates. Unfortunately the method used does not allow to measure different

carbohydrates. It would be interesting to compare the carbohydrate content in juice and juice

drinks.

I did not manage to identify any scientific research performed in Estonia to investigate the

content of unsweetened cranberry juices.

Nevertheless, I have possibility to compare my research data with data available on USDA


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(United States Department of Agriculture, Agricultural Research Service, n.d.) web page.

According to this web page 100 ml of unsweetened cranberry juice contains 12,2 g

carbohydrates, and 9,3 mg vitamin C (United States Department of Agriculture, Agricultural

Research Service, n.d.). According to my results 100 ml of cranberry juice contains 15,2 mg

vitamin C and 10,22 mg of sugar. The differences in my research results and the data on

USA government official web page can be explained, because the content of fruits is

dependent on the ripeness of berries, and the growth conditions of berries (Tervise Arengu

Instituut, n.d., Milleks puu- ja köögiviljad?). Juice contents can also differ due to

manufacturing methods, because it is not described on given web page if the juice was

pasteurized or not, and if yes, on which temperature and what was the time of exposure.

Cooking losses of ascorbic acid depend on degree of heating, surface area exposed to water,

oxygen, pH and presence of transition metals (Naidu, 2003).

Web page of Estonian National Institute for Health Development states, that 100 g

cranberries contain 20 mg vitamin C and 6,8 g carbohydrates, of which 3,5 g of

carbohydrates can be absorbed by the body (Tervise Arengu Instituut, n.d.,

Toitumisprogramm).

Also this web page states, that juice drinks like Aura and Põltsamaa, which were investigated

by myself, do contain medium amount of 10 g of carbohydrates per 100 g of drink. All these

carbohydrates can be absorbed by the body. The creators of web page have obtained this

information from the juice producers. The web page also claims that such juice drinks usually

contain about 30 mg vitamin C, but the data about vitamin C content in juice drinks on

Estonian National Institute for Health Development web page does not come from local

producers. The data is taken from UK databases with similar content according to the web

page references (Tervise Arengu Instituut, n.d., Toitumisprogramm). However, in UK it is

quite common to add vitamins to juice drinks, whilst in Estonia it is not.

I have investigated web data of juice producers and also information on juice drink packages,

and there was no note of vitamin C in the list of ingredients. I have also contacted Asta Übner

from Põltsamaa Felix quality department (Appendix 2), who has confirmed that there could

be no vitamin C in Põltsamaa cranberry juice drink due to manufacturing process. Therefore I


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think that my results showing that these juice drinks do not contain vitamin C at all, are

correct.

According to the Chief Officer of Food Safety Department of Ministry of Agriculture Katrin

Lõhmus the main contents of juice drink are sugar and water and its energetic value is quite

often higher that of any lemonade. The content of these drinks is not regulated by local law

and they contain quite often sweeteners, food colouring, artificial flavouring, acidity

regulators, and preservatives (Karin Volmer, 08.07.2013).

From the results I obtained I can conclude that cranberry juices, drinks are artificially made

to be similar to pure cranberry juice, sugar has been added to obtain similar carbohydrate

level, and citric acid to obtain similar pH level, but the ingredients added are not of natural

cranberry origin. Vitamins have been destroyed by excessive heating. Therefore it can be

concluded, that cranberry juice drinks are not healthy products like cranberry juices, they

contain artificial additives and lack vitamins present in juices. The drinks should be used with

caution due to their added sugar content, and whenever possible, a natural juice should be

chosen.


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7. Bibliography

1. Fyhle et al, 2013, Organic Chemistry 11th Edition, John Wiley & Sons, Inc.

2. Grzegorz Bartosz, 2014, Food Oxidants and Antioxidants, Chemical, Biological and

Functional properties, Taylor & Francis Group, LLC

3. Karin Volmer, 08.07.2013, Maaleht, Mahl, nektar, mahlajook – mis on mis?

4. Maser et al, 2009, Laste ja noorte toitumissoovitused, Ecoprint AS

5. Naidu K Akhilender, 2003, Vitamin C in human health and disease is still a mystery?

An overview, Nutrition Journal 2:7

6. Oyetade et al, 0.9-10.2012, Stability Studies on Ascorbic Acid (Vitamin C) From

Different Sources, IOSR Journal of Applied Chemistry (IOSR-JAC) ISSN: 2278-

5736, Volume 2, Issue 4, PP 20-24

7. Addy et al, (03.07.2004), “pH and Alkalinity”, Available:

http://www.uri.edu/ce/wq/ww/Publications/pH&alkalinity.pdf [04 Sep 2013]

8. A national resource for computational science education, (n.d.), Determining the

Amount of Sugar in Soft Drinks, Available:

http://www.shodor.org/ssep/lessons/soda/sugar.html [06 Sep 2013]

9. An information service of the National Institute of Diabetes and Digestive and Kidney

Diseases (NIDDK), (05.07.2013), Do You Know Some of the Health Risksof Being

Overweight?, Available: http://win.niddk.nih.gov/publications/health_risks.htm [08

Sep 2013]

10. Eger Ninn, (04.05.2012), Põhitoitained: kui palju vajab organism süsivesikuid.

Available: http://www.tarbija24.ee/830264/pohitoitained-kui-palju-vajab-organism-

susivesikuid [04 Sep 2013]

11. Natural History Museum University of Tartu, (n.d.), Sõnastik, Available:

http://foodweb.ut.ee/Sonastik_187.htm?word=Pastoriseerimine [05 Sep 2013]

12. Tervise Arengu Instituut, (n.d.), Milleks puu – ja köögiviljad?, Available:

http://www.toitumine.ee/kampaania/5peotait/why.html [07 Sep 2013]

13. Tervise Arengu Instituut, (n.d.), Toitumisprogramm, Available: http://tap.nutridata.ee/

[04 Sep 2013]

14. United States Department of Agriculture, Agricultural Research Service, (n.d.),

National Nutrient Database for Standard Reference, Available:

http://ndb.nal.usda.gov/ndb/foods/show/8395 [06 Sep 2013]


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15. University of Canterbury, (n.d.), Determination of Vitamin C Concentration by

Titration, Available:

http://www.chemteach.ac.nz/investigations/documents/vitaminc_iodate.pdf [04 Sep

2013]


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8. Appendix 1

Sugar volume evaluation

a)

Graph 3: Sugar solution volume/density ratio standard graph

b)

Graph 4: Juice sugar volume evaluation using standard graph

1.02

1.04

1.06

1.08

1.1

1.12

1.14

0 5 10 15 20

density

sugar volume

y

Linear (y)


25

9. Appendix 2

Correspondence with Asta Übner from Quality Control Department, AS Põltsamaa

Felix from 17th of September 2013

Lugupeetud Mirjam Lätt.

Meie arvates ei ole Põltsamaa Jõhvikajoogis C -vitamiin säilinud, sest tegemist on tundliku

vitamiiniga, mis termilisel töötlemisel laguneb.

Jõhvikajook on valmistatud jõhvikamahla kontsentraadist vee ja suhkru lisamisega.

Kontsentraadi valmistamise ( mahla kokkuaurutamine) ja joogi valmistamise

(pastöriseerimine enne villimist) etappides on jõhvikas läbinud kaks korda kuumtöötluse,

mis kahandab C-vitamiini sisalduse olematuks.

Lugupidamisega,

Asta Übner

Dokumentatsiooni spetsialist/ Kvaliteediosakond

Telefon: +372 77 66 192

E-post: [email protected]

AS Põltsamaa Felix, Tallinna mnt. 1, 48103 Põltsamaa, Eesti

Dear Mirjam Lätt

According to our opinion no C vitamin has been preserved in Põltsamaa Jõhvikajook, as

vitamin C is sensitive vitamin what undergoes destruction during thermal processing.

Cranberry drink has been prepared from cranberry juice concentrate by adding water and

sugar. Cranberries have undergone heating twice in phases of preparing concentrated juice

(steaming) and juice drink (pasteurisation prior to bottling), and this reduces the content of


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vitamin C to non-existent.

Sincerely,

Asta Übner

Documentation Specialist/ Quality Control Department

Sihikindlus - Pühendumus - Täpsus

Phone: +372 77 66 192

E-mail: [email protected]

AS Põltsamaa Felix, Tallinna mnt. 1, 48103 Põltsamaa, Estonia

miina härma gümnaasium - Õpetaja erkki...in juice drinks, the amounts of sugar and ph values were...

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