• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Measurement of the vitamin C content of fruit juices

Extracts from this document...


James Hobbs 10IP Measurement of the vitamin C content of fruit juices Plan: Aim: To investigate the effect of heating on the concentration of vitamin C in fruit juice. Introduction: DCPIP is a purple dye that is decolourised by adding vitamin C or a fruit juice that contains vitamin C. If a standard solution of DCPIP is used then the vitamin C content of different fruit juices can be compared, the more juice it takes to decolourise a standard of DCPIP than the smaller the concentration of the vitamin C in the juice. If the DCPIP solution is first tested with a known concentration of Vitamin C (ascorbic acid) then it is possible to calculate the vitamin C content of other juices. Vitamin C is found in foods such as oranges, lemons, grapefruits, tomatoes, fresh green vegetables and potatoes. A lack of vitamin C causes a disease known as scurvy. The symptoms of this are; Fibres in connective tissue of skin and blood vessels do not form properly, leading to bleeding under the skin, particularly at the joints, swollen, bleeding gums and poor healing of wounds. Vitamin C cannot be stored in the body, so there needs to be a daily intake of vitamin C. Vitamins are group of organic substances quite unrelated to each other in their chemical structure. ...read more.


I.e. you have added 0.6 cm�. Safe Test: Do not carry the syringe around the room. Hold the syringe with the needle pointing down. Wear safety goggles at all times. If the syringe appears blocked, do not force it. Prediction: I thick that the longer the vitamin C is heated the more solution it will take for the DCPIP to decolourise. Observing Time the fruit juice was boiled for (Hours) Vitamin C added -Test 1 (cm�) Vitamin C added -Test 2 (cm�) Vitamin C added -Test 3 (cm�) Vitamin C added -Average (cm�) Standard solution - 0.9 0.95 0.9 0.92 A Fresh 1.0 1.0 - 1.0 B 1/2 hour 1.08 1.1 - 1.09 C 1 hour 1.15 1.12 - 1.14 D 2 hours 1.5 1.4 - 1.45 E 5 hours 2.25 2.2 - 2.23 Analysis I took the averages of my results and used them in the equation mentioned earlier. Percentage of Vitamin C = Average volume of vitamin C used x 0.1 in fruit juice Average volume of fruit juice used Percentage of Vitamin C = 0.92 x 0.1 in fruit juice A 1.0 = 0.092 = 0.09% Percentage of Vitamin C = 0.92 x 0.1 in fruit juice B 1.09 = 0.084403669 = 0.08% Percentage of Vitamin C = 0.92 x 0.1 in fruit juice C 1.14 = 0.080701754 = 0.08% Percentage of Vitamin C = 0.92 x 0.1 ...read more.


I had one anomalous result, the test of fruit juice B. The amount of vitamin C added should have been about 0.12 cm� instead of the 0.09 cm� that I got. This means I did not put enough fruit juice into the DCPIP, which shows a human error as I said before. This was the only anomaly, which shows the results were quite accurate, but also points out the importance of repeating the experiment three times, so that you can see any anomalies. As I said before, you could use a more precise syringe to get more accurate results. Also the more times you repeat the experiment the more accurate the experiment, which means the more accurate the results. Ensure that the Standard solution is tested well as that result effects the end overall results. Another experiment, which could be done, is; to compare the vitamin C contents of Oranges, Lemons and grapefruits, to see which one had the highest amount of vitamin C. The method would be: * Draw up 2 cm� fresh orange juice into a syringe. Add this drop by drop to 1 cm� of DCPIP solution. * Record how much was added and repeat the experiment to obtain averages. * Repeat the experiment with orange and grape fruit juices * Compare the results of all three samples. The one, which uses the least amount of juice, contains the most vitamin C in the juice. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Living Things in their Environment section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Here's what a teacher thought of this essay

3 star(s)

A fairly good account but more detail need in places and errors made in display of results.

Marked by teacher Adam Roberts 16/07/2013

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Living Things in their Environment essays

  1. Marked by a teacher

    A2 Biology Coursework -Investigation into the effect of different concentrations of antibiotics on the ...

    4 star(s)

    with a hand wash * I wore a Lab coat * I wiped the table with a disinfectant to reduce contamination by killing any bacteria on the surface * I made sure that the apparatus I used was capable of carrying a certain amount of solution to reduce the risk

  2. Marked by a teacher

    In this experiment, mung bean seedlings and Brine shrimp eggs were used to study ...

    4 star(s)

    Procedure : (A) Germination of mung bean seeds 1. About 50 mung bean seedlings are soaked overnight. 2. About 1 cm thick of cotton wool is cut and placed in a sterile Petri dish. The cotton wool is wet thoroughly with water.

  1. Marked by a teacher

    An Investigation into a Woodlice's Preferred Choice of Environment.

    3 star(s)

    Sections 1 and 2 have cotton wool underneath them, whilst sections 3 and 4 have silica gel underneath them. Sections 2 and 4 also have black paper over the top of them, stopping any light form getting in. This mean that:- Section 1 - wet/light Section 2 - wet/dark Section

  2. The importance uses of micro organisms.

    They may well have major environmental problems. Also because viruses are simple organisms they are used greatly by scientists in research for understanding cells functions and reproduction. This has already resulted in the understanding of DNA and genes, but in the future this knowledge could help us change cells or replace mutated genes with healthy genes with diseases we have answers for.

  1. This assignment is about planning and designing practical experiment to carry out an investigation ...

    * Lab coats are worn to prevent any exposure of agar on clothes. * Hands must be washed with disinfectant, after the experiment is finished to avoid any later consumption of the bacteria. Average Diameter of clear zone/cm3 Antibiotics reading of dish 1 reading of dish 2 D1+D2 Average /cm3

  2. 'Bacteria. Friend or Foe?' Bacteria is something we are all reminded of ...

    protecting our children from playing outside in a little mud is really helping us in the long run will remain. No one is suggesting we return to a state similar to that witnessed in the African nations although a happy medium may need to be found if the developed world is to reduce its new found problem of allergies.

  1. Investigating Seed Germination. Hypothesis If there is water, oxygen and a suitable ...

    This would then lead to the lengths of the seedlings being invalid as more than one condition is not present. All set ups will receive the same amount of oxygen available in the room, except set up 3. Set up 3 will be covered with a layer of oil where oxygen will not get through to the seed.

  2. year 9 sycamore investigation

    Dependent: Time of sycamore seed landing (sec) Control: * Height of drop * Model made out of same material * Model of sycamore fruit has "wings" of the same length * Wind speed * Mass added on the same place Fair test: * Height of drop will be two meters * We will make a model out

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work