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What amounts of vitamin C are in different brands of orange juice.

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GCSE Biology Coursework: What amounts of Vitamin C are in different brands of orange juice. PLANNING: Aim: The aim of this experiment is to discover the amount of vitamin C (ascorbic acid) in different brands of orange juice. Introduction: The polymer for vitamin C is C6H8O6. Vitamin C (Ascorbic acid) has a melting temperature of 190�C. It is very unstable and decomposes quickly. For example if a cucumber was cut and left for half an hour it would lose over 20% of its Vitamin C. Vitamin C decomposes over time and on exposure to sunlight, oxygen, heat, water, prolonged storage, overcooking, processing, antacids, alcohol, antidepressants, birth control pills and steroids. Also used in the experiment is dichlorophenolindophenol (DCPIP for short). The dichlorophenolindophenol solution is unstable and needs to be freshly prepared each time it is used. At the end of the titration with the iodine solution it is difficult to detect if the fruit juice is coloured as the Iodine solution is red-brown and the ending of the titration is detected by the loss of this colour. Vitamin C is one of the most popular vitamins yet it is also the vitamin most scientists are confused about. Without it an animal would die. Almost all animals make vitamin C in their bodies. Man is the only exception to this and the only way he can get it is through his diet or supplements. The amount required depends on the state of your body, if you are ill then you need more vitamin C. If you have an unhealthy lifestyle then your body requires more vitamin C. There is a big difference between the amount needed to prevent diseases such as scurvy and the amount needed to obtain optimum health. ...read more.


The trend was that the higher the number of Mg's of vitamin C per 100g's of the juice the producer said their product contained, the higher the amount of DCPIP that was needed to change the juices colour. For example Waitrose claimed that their juice had 25 Mg's of vitamin C per 100g's and this was one of the lowest amount of vitamin C claimed and Waitrose juice contained the least vitamin C. One problem is that Libby's original claimed that there was just 24 Mg's of vitamin C in their juice yet it needed a lot more DCPIP to change its colour then Waitrose juice did which seems to suggests that there is a higher concentration of vitamin C in the Libby's original brand. I think the solution to this is that when the Libby's juice undergoes some processing some of the vitamin C will be lost and so the drink will have to be fortified, therefore I believe the manufacturers claim of 24 Mg's of vitamin C in the juice is before the juice is fortified. I decided to find out exactly the number of milligrams there were in each juice and to discover if what the manufacturer said was true. The concentration of the DCPIP was 0.125%. 1g = 100ml 10ml = 0.1g 10ml = 0.1g = 100ml 100mg = 0.1g 10ml = 100mg Waitrose: 25mg of vitamin C per 100 ml is the amount stated by the manufacturer. 25 over 100 as a fraction in its lowest terms is 1 over 40. As a decimal it's 0.025. There is 6.03ml of vitamin C per 10ml. This is the figure I came up with. ...read more.


These results are again reliable as the numbers are close. Libby's (organic)- 6.6 6.2 6.35 = 19.15. These results are accurate and reliable as the numbers are close. Tesco- 7.8 7.1 7.6 = 22.5. These results aren't very reliable mainly due to the anomalous result. Del Monte- 7.0 7.1 7.5 = 21.6. These results are quite reliable as the numbers are relatively close. Sunpride- 6.7 7.0 6.55 = 20.25. These results are close so they are reliable. Sunny Delight- 8.9 9.0 8.95 = 26.85. These results are the most reliable as they are the closest together. Overall my results are quite reliable. I did further work with vitamin C tablets to see what kind of results I would get with them and to see if my method was as effective with something high in vitamin C. The tablets dissolved in water and I used 10ml for each experiment, the same amount as I used of juice. These are my results Experiment number DCPIP used 1 38.2 2 42.7 3 41.0 These figures are reliable and they also showed just how little vitamin c is actually in the orange juice compared to these. Obviously these tablets are used as supplements to people's diets. Therefore I believe that my results were sufficient to make a decent conclusion on this experiment. Extensions to this experiment could include using oranges rather then orange juice, from different countries and squeezing them until you have 10ml of juice then testing in the same way as the juice was and seeing which country produced the oranges with the most vitamin C. Another experiment could use different kinds of juiced of different fruits and seeing which fruit juice has the highest vitamin C content. This experiment could also be done in the same way but with vegetables to see which vegetables had the most vitamin C in them. . ...read more.

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