The experiment was tested with titrations being done each week of the pineapple juice which was stored in various conditions. Results were recorded and compared to previous week’s results in order to determine whether there is in fact deterioration due to storage of vitamin C.
The experiment was to research the deterioration of Vitamin C in pineapple juice due to different storage conditions. The outcome of the experiment was that the Vitamin C in the pineapple juice which was stored in warmer conditions such as the hot water cupboard and window sill, deteriorated more rapidly than the Vitamin C in the Pineapple juice which was stored cooler conditions such as the fridge and freezer.
Differences between the deterioration of different pineapple juice storages was not evident after the first drop into the Dichlorophenol because all 4 differently stored pineapple juices caused the Dichlorophenol to changed colour. The pineapple juice needed to be diluted in order to determine which storage condition caused the vitamin C to deteriorate more rapidly. The faster the pineapple juice changes colour the more Vitamin C is in the solution.
The colour of the cooler stored pineapple juice didn’t need as much diluting, in order for it not to change at the first drop, as the pineapple juice that was stored in warmer conditions. Therefore it was determined that the Vitamin C in the pineapple juices stored in the hot water cupboard and on the window sill deteriorated more rapidly than the pineapple juice stored in the freezer and fridge.
The appearance of ascorbic acid is white to light-yellow crystals or powder, and it is water-soluble. A vitamin is a chemical other than a protein, carbohydrate, fat or mineral salt. These are essential constituents of the food for animals. (Ron Jonk, 2000)
The role of Vitamin C in the human body is often taken for granted or not understood. Society often attempts to contain Vitamin C in there everyday diet by consuming what is mistaken as a healthy fruit juice. A lot of commercial fruit juices destroy large amounts of nutrients because there are large numbers of added sugar and food additives which preserve the flavour or improve the taste and appearance. It is said that the vitamin C content in fruit juices is affected by the temperature and storage time. Vitamin C is important for living organisms; it helps in the synthesis of collagen which is an important component of ligaments, blood vessels, bone and tendons. Collagen is found throughout the body; it is present in cartilage and connective tissues its function is to separate skeletal and smooth muscle cells. (Ron Jonk, 2000) (fitness health zone, 2007)
Vitamin C is very sensitive to even the slightest heating because it is oxidized readily in light, air and when heated. Vitamin C is one of the least stable vitamins. Antioxidants such as grade seed extract, curcumin, pycnogenol, glutathione and vitamin E scavenge and preserve vitamin C. However in order for these supplements to have an affect the body must first be consuming adequate vitamin C. The average dose that humans must consume of vitamin C per day is 3-12 grams. (Nagy Steven, 1980)
Vitamin C participates in numerous biochemical reactions, this is why vitamin C is important for every body process. A main disease that is caused my vitamin C deficiency is Scurvy. Scurvy is characterized by anaemia, loose teeth, easy bruising, poor healing and fragility of blood vessels. It is also know that vitamin C deficiency can cause wait loss, depression, fatigue and weakness. (Rickman et al., 2007) (Mammas health, 2001)
Unlike most mammals, humans and guinea pigs are not able to make their own vitamin C, this means they lack the enzyme to convert glucose to vitamin C; therefore it is important that we obtain it in our diet. The body cannot store vitamin C because it is a water-soluble vitamin. Once the body has used up what is needed excess is eliminated, because of this it is important to consume adequate quantities everyday. (BBC,2007)
Guinea Pigs are not able to make their own Vitamin C
The human Body is not able to make its own Vitamin C
The experiment is designed to investigate the deterioration of vitamin C when it is being stored in 4 different storage conditions; these conditions are the Freezer, Refrigerator, Hot water cupboard and Window sill. This experiment will be taking place over a 4 week period and will be closely monitored. Data will be collected and results will be compared.
Aim: To determine whether Vitamin C deteriorates in different storage conditions and the rate of it deterioration.
We expect that after a certain amount of time the vitamin C level will decrease in the different storage conditions. The Warmer storages such as the hot water cupboard and the window sill will decrease more rapidly than the refrigerated and frozen storage conditions.
How They Are Controlled
Same amount used each time
Same pineapple juice used out of the same bottle and also the same amount
4 Storage locations remain the same, hot water cupboard, window sill, fridge and freezer
0.5% Ascorbic acid
0.2% Ascorbic acid
0.1% Ascorbic acid
Method Part A, Setting up:
1. Retort stand was set up and clamp was adjusted to it.
2. Dilation tube was secured to the clamp
3. Funnel was placed on top of dilation tube
Method Part B, Ascorbic Acid titration:
1. 10 drops of 6-Dichlorophenol 0.05% was added to the 50ml beaker
2. 0.05% Ascorbic Acid was poured into the funnel
3. 250ml beaker was stood under dilation tube to capture drops
4. Dilation tube handle was twisted horizontal until a steady constant drip occurred
5. One drop at a time entered the 6-Dichlorophenol 0.05% and changes were recorded
6. Steps 3-5 with 0.1% and 0.2% Ascorbic Acid were repeated
Method Part C, Pineapple Juice titration:
1. 10 drops of 6-Dichlorophenol 0.05% was added into the 50ml beaker
2. Pineapple juice was poured into funnel
3. 250ml beaker was stood under dilation tube to capture drops
4. Dilation tube handle was twisted horizontally until a steady constant drip occurred
5. One drop at a time entered the Pineapple juice, changes were recorded.
Method Part D, Pineapple Juice different storage conditions titration:
1. 10 drops of 6-Dichlorophenol 0.05% were added into the 50ml beaker
2. Refrigerated Pineapple juice was poured into the funnel
3. 250ml beaker was stood under dilation tube and to capture drops
4. Twist dilation tube handle horizontal until a steady drip occurs
5. One drop at a time entered the refrigerated Pineapple juice, changes were recorded
6. Was repeated with hot water cupboard stored pineapple juice, Window sill stored pineapple juice and freezer stored pineapple juice
7. Repeated weekly
When the experiment first commenced and the pineapple juice came directly from the bottle and had not been put into various storage conditions, after one drop of 0.05% Ascorbic acid the original colour of the Dichlorophenol, which was dark blue, turned to a Rich purple. This result showed that the Ascorbic acid in the Pineapple juice was still very rich, because it only took one drop until the colour changed. It was investigated further and it was discovered that the final colour that the Dichlorophenol would reach when Ascorbic Acid is added was a cloudy maroon purple, which was very close to being clear. When pineapple juice that had not been stored in various conditions, was added it took three drops until the colour remained the same, which was close to clear. It was then investigated further and the pineapple juice had been stored in four different storage conditions, these were the fridge, freezer, hot water cupboard and the window sill. After the pineapple juice had been stored for one week, a titration was taken from each of the four.
The pineapple juice that had been stored in the fridge showed that after one drop the colour turned to rich purple, this result was the same as the one from the previous week. However more drops were added to the Dichlorophenol solution and it was being investigated how many drops it would take until the colour remains the same. This time it took four drops rather than three until the colour reached close to clear. This result proved that a minimum amount of Ascorbic acid (vitamin C) had been lost after one week of being stored in the fridge at approximately 2.5C. After two weeks of being stored in the refrigerator the colour changed to a rich purple after one drop, just like it had done in previous weeks, however this time it took five drops until the colour remained the same which was close to clear. In the third week of being stored in the refrigerator the colour of the Dichlorophenol once again changed after only one drop of Pineapple juice and the final colour was reached after five drops. After four weeks a final titration was taken from the refrigerated pineapple juice and once again the colour changed after one drop of pineapple juice, however this time it took six drops until a final colour was reached. Over the four weeks of refrigeration the Dichlorophenol changed at one drop to rich purple however it also showed that minimum amounts of Vitamin C were being lost as the weeks past because it was constantly taking extra drops until an almost clear final colour was reached.
The results of the Pineapple juice which was being stored in the freezer was simular to the refrigerated stored results. In the second week, when the pineapple juice had been stored for one week, the colour once again changed after one drop however at the second drop the colour remained the same, it then changed at the third drop and then once again remained the same, at the fifth drop it changed to a slightly clearer colour and that was the final colour that the Dichlorophenol reached. These results were different to previous results because the Vitamin C in the pineapple juice did not have a consistent change to the Dichlorophenol. In the third week the colour once again changed after one drop however, instead of the final colour being reached at five drops it was reached at four, this would mean that there was an increase in Vitamin C, however this change may have also been caused by inaccurate recording of results or a common error. A common error could be that at the beginning of the experiment when ten drops of Dichlorophenol were added the drops may have been a different size to the ones in the previous experiment or a mistake was made when counting the amounts of drops that are needed. In the fourth and final week of the pineapple juice being stored in the freezer, the Dichlorophenol colour changed after one drop of ascorbic acid and the final colour was reached after four drops, this last set of results was the same as the ones from the week before.
The refrigerated and frozen pineapple juices were very simular in their results. In previous studies of this experiment it is believed that if the fruit juice is being stored in a cool condition there are no large amounts of vitamin C lost and if there are then it is over a long period of time (Peters, Gustavus A, and Hugh E. Martin, 1999)
In the second week, when the Window sill Pineapple juice had been stored for one week, the colour did change after one drop, however instead of It being a rich purple it was a dark purple, it did not show as much change as the refrigerated and frozen pineapple juices did. This shows that greater amounts of Vitamin C were lost when the pineapple juice was stored on the window sill within the one week of storage, than the refrigerated and frozen storages. The final colour was reached at five drops of Pineapple juice. In the third week, after the first drop of pineapple juice was dropped into the Dichlorophenol the colour once again changed to dark purple. The final colour was reached after seven drops. The results of the drops did not change constantly as after two drops, the next two drops did not show any change, however the fifth drop made the Dichlorophenol slightly lighter, then once again at the sixth drop there was no change until at seven drops the Dichlorophenol reached its final colour and there were no more changes. At four weeks the colour changed to dark purple after one drop and it took seven drops until the final colour was reached.
In the second week when the hot water cupboard stored pineapple juice had been stored for one week the colour of the Dichlorophenol changed to dark purple after one drop of pineapple juice had been added. The final colour was reached at four drops. As this set of results is compared to the first week of storage results from the window sill pineapple juice, it is shown that both juices changed to dark purple after one drop; however the results are different due to the fact that the window sill pineapple juice stopped changing colour at five drops while the hot water cupboard pineapple juice stopped changing colour at four drops. This indicates that after one week greater amounts of vitamin C were found in the hot water cupboard stored Pineapple juice. In the third and fourth week, results changed dramatically as the final colour was reached at only three drops. This would indicate that there was an increase in Vitamin C over the last two weeks of the experiment. However there are other explanations to the sudden change, there may have been inaccuracy in the results, eg: If the drops of the Pineapple juice are large or smaller than they previously have been then there will be a change. Results also change if the ten drops of Dichlorophenol are larger or small.
Due to the occasional errors in results there was confusion of the final outcome of the experiment so further tests were done. All the pineapple juice samples were once again titrated however this time it was aimed that the colour would not changed after the first drop. With the Refrigerated and frozen pineapple juice, 1 ml was taken and mixed with 9mls of water however the colour of the Dichlorophenol still changed after one drop, so another 1 ml of this solution was taken and mixed with another 9 mls of water. Once this solution was dropped in the Dichlorophenol the colour changed at 2 drops. This test was also done with the window sill and hot water cupboard pineapple juice. 1 ml of the juice solution and 9 mls of water were used, However the colour of the dichlorophenol still changed at one drop, so 1 ml of this solution was taken and 9mls of water was added, once again the dichlorophenol still changed at one drop, so another 1 ml of this solution was taken together with 9 mls of water and then the dichlorophenol changed colour at two drops.
These results show that the juices that were stored in the cooler conditions changed colour much faster, this indicates that more Vitamin C was precent. The hot water cupboard and window sill juices took much longer to change colour because they had been stored in warmer conditions and therefore lost vitamin C over the three weeks of storage.
This experiment could use further investigation, due to the fact that there was some inaccuracy in the results. Result could have been more accurate if pictures of each solution were taken and compared each weak. The way people may express different terms will vary and this becomes a problem when there are two people working on the same experiment so there for it is important that other ways of recording results, rather than just writing them down, are used. In this experiment there were also some things that were not able to be controlled. The pineapple juice being stored in a busy school lab the refrigerator, freezer and hot water cupboard may have been opened several times a day, compared to other private labs that continuously have them closed. Another situation that could not be controlled was the whether conditions that the pineapple juice at the window sill were in. The experiment could have turned out completely different if it was the middle of summer and the sun was constantly shining during the day, or if it was an extremely cold winter and the pineapple juice was continuously standing in the cold.
The outcome of the experiment displayed that Vitamin C concentration had deteriorated more rapidly in warmer storage conditions than in cooler conditions.
Throughout the experiment the Dichlorophenol continued to change colour at one drop of pineapple juice, however the refrigerated and frozen juice caused the Dichlorophenol to go rich purple, while the warmer storage conditions which were the hot water cupboard and window sill caused the Dichlorophenol to change to dark purple after the first drop.
Throughout the experiment there were several common errors and inaccuracy. In order to prevent or improve in future experiments it is recommended that plenty different types of result taking is done rather than just writing down the results. It is also important to take in account the amounts of each substance that is being added, at times the size or amount of Dichlorophenol or Pineapple juice drops varied is size.
The experiment did deliver a certain outcome and this was that deterioration is much more rapid in warmer conditions. The cooler the condition that the fruit juice is stored in, the greater the amount of vitamin C it will contain.
Graph Explanation: This graph displays the 0.20%, 0.10%, 0.05% ascorbic acid being tested with 6-Dichlorophenol. It displays the number of drops it needed until a final colour was reached. The 0.20% ascorbic acid reached the final colour first because it has the highest level of concentration.
Graph Explanation: This graph displays the results of the freezer stored pineapple juice from 1-4 weeks. This graph displays a decrease of vitamin c from week 1-2, an increase of vitamin c in weeks 2-3 and then no change between week 3 and 4. The sudden increase in Vitamin C may have also been because of an error when recording data.
This graph displays the results of the windowsill stored pineapple juice from weeks 1-4. This graph displays that the vitamin C decreased in the 4 weeks of storage.
This graph displays the results of the refrigerator stored pineapple juice from weeks 1-4. It displays a constant decrease in Vitamin C levels over the 4 weeks period.
This graph displays the hot water cupboards results from weeks 1-4. It displays that there was a decrease in weeks 1-2, an increase in weeks 2-3, and no change from weeks 3-4. These results may have varied like this because of errors in recording or not recording accurately.
Due to possible errors that may have occurred in previous experiments and unsure outcomes, another test was completed by diluting the pineapple juice with water and tested how much dilution it would take so the pineapple juice does not change colour after the first drop. The Freezer stored and refrigerator stored pineapple juice took less dilutions in order for it to not change after the first drop. The Hot water cupboard and window sill stored pineapple juices needed 3 dilutions until it would not change colour after the first drop however the freezer and refrigerator stored pineapple juice only took
Lab partner Brooke Power for assisting me with the extended experimental investigation of investigating deterioration of Vitamin C due to different storage conditions.