Miina Härma Gümnaasium. Mirjam Lätt Chemistry Comparison of Homemade and Manufactured Cranberry Juices Available in Estonia Extended Essay

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1 Miina Härma Gümnaasium Mirjam Lätt Chemistry Comparison of Homemade and Manufactured Cranberry Juices Available in Estonia Extended Essay Supervisor: Erkki Tempel Candidate Session Number: Number of words: 3907 Tartu 2013

2 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 KIO 3 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. 2

3 Table of Contents Abstract (word count: 299) 2 Table of Contents 3 1. Introduction 4 2.Research question 5 3. Background information Selection of topic Ascorbic acid Carbohydrates ph 9 4. Method Measuring vitamin C concentration by titration Calculating vitamin c concentration in homemade juice Calculating vitamin c concentration in ecological juice Sugar Level Evaluation-problems/improvements Conclusions Bibliography Appendix Appendix

4 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. 4

5 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 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, ) In my family there has always been an understanding that lemonade and sodas are not healthy 5

6 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 (C 6 H 8 O 6 ) 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). 6

7 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(H 2 O)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). 7

8 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 CO 2 + y H 2 O + solar energy: Cx(H 2 O)y + x O 2 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 C 12 H 22 O 11. 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, ) 8

9 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 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). 9

10 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 KIO 3 was needed to oxidize all vitamin C in solution, after what the solution become blue due to the ability of excess I 2 to change the colour of starch into blue. When iodate ions (IO 3 ) are added to an acidic solution containing iodide ions (I ), an oxidation-reduction reaction occurs. IO I - + 6H + = 3I 2 +3H 2 O 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 + I 2 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: 10

11 5 different juices mol/dm 3 KIO 3 solution 10% KI solution 0.1 mol/dm 3 HCl solution 0.5% (C 6 H 12 O 6 )n solution 25.0 cm 3 pipette ± 0.1 cm cm 3 burette and stand ± 0.1 cm cm 3 volumetric flask ± 0.1 cm 3 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 KIO 3 solution. Pipette was filled up to 25 cm 3 juice that was placed into a conical flask. 5 ml of 10% KI solution, 50 ml HCl and 3 ml (C 6 H 12 O 6 )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. KIO 3 was let to titrate drop by drop. The notes were taken of how much KIO 3 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 Titration II Titration III Average titration ± 0.05 cm 3 ± 0.05 cm 3 ± 0.05 cm 3 ± 0.05 cm 3 Homemade 3.7 cm cm cm cm 3 Aura no colour change no colour change no colour change Ecological 3.2 cm cm 3 3.2cm cm 3 Põltsamaa no colour change no colour change no colour change

12 Gutta no colour no colour no colour - change change change Calculating vitamin c concentration in homemade juice Initial data M (C 6 H 8 O 6 ) = 176 g/mol V2 ((C 6 H 12 O 6 )n) = 3 ml ± 0.05 ml p ((C 6 H 12 O 6 )n) = 0.5% c (KIO 3 ) = mol/dm 3 c (HCl) = 0.1 mol/dm 3 L1V1 (homemade) = 25 ml ± 0.05 ml V3 (KI) = 5ml ± 0.05 ml p3 = 10% Reactions to consider 1.) IO I - + 6H + = 3I 2 +3H 2 O 2.) C 6 H 8 O 6 + I 2 =2I - + C 6 H 6 O 6 + 2H mol KIO cm 3 z 3.6 cm 3 Z = x 3.6/1000 Z = mol KIO 3 was used to oxidise ascorbic acid As a result of reaction 1, we will have 3 moles of I 2, originating from 1 mole of KIO mole y-3 y= mol (I 2 ) 12

13 According to reaction 2, 1 mole of I 2 is used to oxidise 1 mole of C 6 H 8 O 6 Ratio is 1:1, therefore n (C 6 H 8 O 6 ) = mol c =! => c = /0.025 = M! n =! => m = *176 = g = mg/25ml! The amount of vitamin C in 25 ml of homemade juice is mg ml X2-100 ml X2= mg/100ml The amount of vitamin C in homemade juice is mg/100 ml Calculating vitamin c concentration in ecological juice Initial data M (C 6 H 8 O 6 ) = 176 g/mol V2 ((C 6 H 12 O 6 )n) = 3ml ± 0.05 ml p ((C 6 H 12 O 6 )n) = 0.5% c (KIO 3 ) = mol/dm 3 c (HCl) = 0.1 mol/dm 3 L1V1 (ecological) = 25 ml ± 0.05 ml V3 (KI) = 5ml ± 0.05 ml p3 = 10% Reactions to consider 1.) IO I - + 6H + = 3I 2 +3H 2 O 2.) C 6 H 8 O 6 + I 2 =2I - + C 6 H 6 O 6 + 2H + 13

14 0.002 mol KIO cm 3 z 3.2 cm 3 Z = x 3.2/1000 Z = mol KIO 3 was used to oxidise ascorbic acid As a result of reaction 1, we will have 3 moles of I 2 from 1 mole of KIO mole y-3 y= mol (I 2 ) According to reaction 2, 1 mole of I 2 is used to oxidize 1 mole of C 6 H 8 O 6 Ratio is 1:1, therefore n (C 6 H 8 O 6 ) = mol c =! => c= /0.025= M! n =! => m= *176= g =3.3792mg/25ml! The amount of vitamin C in 25 ml of ecological juice is mg ml X2-100 ml X2= mg/100ml The amount of vitamin C in ecological juice is 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: 14

15 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 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/cm 3 ) Mass of sugar (g) ± 0.01g 5 51,28 1,026 4, ,58 1,07 8, ,85 1,117 12, 81 15

16 Table 3. Mass of Sugar, Investigated Juices Juice Mass of 50 ml juice (g) Density of juice calculated Amount of sugar (ml) Mass of sugar (g) ± 0.01g Mass of sugar in 100 ml (g) ± 0.01g ± 0.01g Homemade ,11 10,22 Ecological ,1 5,2 10,4 juice Põltsamaa ,3 5,37 10,74 Gutta , ,96 11,92 Aura ,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 16

17 placed into juice and the results were recorded from the Vernier LabQuest that was Mirjam Lätt 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 17

18 C in 100 ml (mg) 100 ml (g) ± 0.01g Home made 15, ,22 Ecological 13, ,4 juice Põltsamaa ,74 Gutta ,92 Aura ,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 KIO 3 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 18

19 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 19

20 (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 20

21 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, ). 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. 21

22 7. Bibliography 1. Fyhle et al, 2013, Organic Chemistry 11 th 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, , 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, , Stability Studies on Ascorbic Acid (Vitamin C) From Different Sources, IOSR Journal of Applied Chemistry (IOSR-JAC) ISSN: , Volume 2, Issue 4, PP Addy et al, ( ), ph and Alkalinity, Available: [04 Sep 2013] 8. A national resource for computational science education, (n.d.), Determining the Amount of Sugar in Soft Drinks, Available: [06 Sep 2013] 9. An information service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), ( ), Do You Know Some of the Health Risks of Being Overweight?, Available: [08 Sep 2013] 10. Eger Ninn, ( ), Põhitoitained: kui palju vajab organism süsivesikuid. Available: [04 Sep 2013] 11. Natural History Museum University of Tartu, (n.d.), Sõnastik, Available: [05 Sep 2013] 12. Tervise Arengu Instituut, (n.d.), Milleks puu ja köögiviljad?, Available: [07 Sep 2013] 13. Tervise Arengu Instituut, (n.d.), Toitumisprogramm, Available: [04 Sep 2013] 14. United States Department of Agriculture, Agricultural Research Service, (n.d.), National Nutrient Database for Standard Reference, Available: [06 Sep 2013] 22

23 15. University of Canterbury, (n.d.), Determination of Vitamin C Concentration by Titration, Available: Mirjam Lätt [04 Sep 2013] 23

24 8. Appendix 1 Sugar volume evaluation a) density y Linear (y) sugar volume Graph 3: Sugar solution volume/density ratio standard graph b) Graph 4: Juice sugar volume evaluation using standard graph 24

25 9. Appendix 2 Correspondence with Asta Übner from Quality Control Department, AS Põltsamaa Felix from 17 th 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: E-post: asta.ubner@felix.ee AS Põltsamaa Felix, Tallinna mnt. 1, 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 25

26 vitamin C to non-existent. Sincerely, Asta Übner Documentation Specialist/ Quality Control Department Sihikindlus - Pühendumus - Täpsus Phone: asta.ubner@felix.ee AS Põltsamaa Felix, Tallinna mnt. 1, Põltsamaa, Estonia 26