Experiment Conclusion

THOUGHTS

We feel the experiments went quite well, with certain faults, such as the breaking of equipment and the anomalous results we received (with regards to the courgette).

Both attempts yielded very similar results, and it appears we made no mistake with the solution concentration.

Our experiments make it clear to us that strawberries have the highest amount of Vitamin C, of the samples that we tested. In all we carried out 4 experiments, the two first experiments looking at the fruits and veg that seemed to have the highest amounts of vitamin C ( Repeating the same experiment twice), and the Second two experiments actually quantitatively looking at the samples we deemed to have the highest relative Vitamin C content. A table is included with our results. We have taken an mean, but would have liked to carry out the experiments a few more times to get a more accurate average.

FURTHER RESEARCH

After we had carried out our experiments we looked online at the actual values of Vitamin C in our samples. This research backed up our results: Strawberries have more Vitamin C per 100 grams(58.8mg opposed to 35mg in an orange). Courgettes have considerably less than the other two. One fruit we didn't look at was Kiwi Fruit, which has 92.7 mg of vitamin C per 100 grams.

ALL SCIENCES
This experiment encompasses biology and chemistry, and we need to add some physics. So here is some physics regarding colour absorption and reflection:
Since the molecular bonds between the atoms of the liquids vibrate with a certain frequency, they interact with light waves (photons) of the same frequency. The liquid therefore absorbs this certain wavelength of light, changing the amplitude of the molecular vibration to a higher state.
The liquid DCPIP in our experiment reflects the blue light since its frequency copes with the molecular frequency. With regard to the chemical properties and reactions of Vitamin C, we must discuss Vitamin Cs chemical composition. Vitaminc Cs chemical formula is C6H8O6, and is derived from glucose, although most Humans can't synthesize it, so must get a supply from outside of the body, by the eating of citrus fruits.

Vitamin C is essential to most animals, as it helps catalyze several metabolic reactions ; Without Vitamin C and these reactions, Scurvy and death usually result. Scurvy is a disease that causes anemia, debility, swelling in various parts of the body, and often loss of teeth. It is famous for mainly affecting sailors in the 16th to 19th centuries, and the supplying of limes to the Royal Navy is why our cousins over the Atlantic name us 'Limies'.The reactions catalyzed by Vitamin C are immensely complicated and are too long to discuss here. With regards to Biology, Vitamin C is essential for life, and as well as keeping the body healthy, may also a part in control of gene expression and translation (a recent hypotheses proposed in 2010, published in the journal 'Nature'). The Vitamin acts as an electron donor for several enzymes, that catalyze reactions as far spread as blood clotting to protein synthesis.

SAMPLE	Amount of DCPIP (1st attempt) cm3	Amount of DCPIP (2nd attempt) cm3	Amount of DCPIP (Average) cm3
Orange	2	2.5	2.25
Strawberry	12	15.5	13.75
Courgette	1	1	1

Blog created by Eduardo Rodarte Aguilera, Philipp Garschina, Matthew Harris, Jack Wood and Enyo Ahovi.

Comparison of Vitamin C levels in Oranges, Strawberries and Courgettes.

This method is used to make a rough comparison between the 3 samples in the title, regarding the amounts of Vitamin C.

ATTEMPT 1

EQUIPMENT

• Pretty much the same as yesterday.
• Additional conical flasks and beakers
• A burette

METHOD

1. Begin with the same amount of each sample. In our case, we used 25 grams.
2. Draw the liquid from the sample into a burette, and apply it drop by drop into DCPIP in a beaker.
3. The DCPIP solution should contain 0.25 grams and 50ml of water.
4. Work out how much sample liquid was required to make the DCPIP solution colourless.
5. Carry out the above stages for he other samples.
6. The comparing of the amount of sample used to completely change the DCPIP solution will give a rough indication of how much Vitamin C is in the food samples.
7. We tried to filter the sample, but that didnt work, as dropping the semi-solid fruit/veg would have wrecked the burette. We used 25 ml of sample.
8. Therefore, we then swapped the experiment around-dropping DCPIP solution into the sample. When the DCPIP no longer becomes colourless, we have our value, and can work out a rough idea of the amount of vitamin C.

RESULTS

ORANGE

It took 2 cm3 of DCPIP for the orange. Orange being a citrus fruit leads us to believe that we may have made an error-There was a slight confusion over the concentration of DCPIP solution.

STRAWBERRY

It took 15.5 cm3 of DCPIP until the reaction would no longer occur.

COURGETTE

It took only 1cm3 of DCPIP until he reaction wouldn't take place. We decided to leave the sample to stand for five minutes to see wether there was really so little vitamin C, or we had had an anomalous result in the previous experiment, that made it look like Courgette had more Vitamin C than it actually had. After 5 minutes there was still no reaction, which led us to believe that yesterdays result was anomalous.

THOUGHTS

We believe we might have made an error regarding the concentration of the Solution. We will repeat the experiment with 1/4 concentrations: 200ml with 0.5g of DCPIP

ATTEMPT 2 

We will add (cm3 at a time) DCPIP solution at a quarter concentration too 25 ml of each of of our samples.

EQUIPMENT

• 250ml conical flask
• 200ml glass beaker
• Mortar and pestle
• Distilled water
• Samples
• Glass rod
• Spatula
• Knife 
• Chopping board
• Knife
• Test tubes and rack 

The Method is much the same as previously detailed-create an extract of 25ml of each sample, and drop by drop add the DCPIP solution, noting down at what point the DCPIP solution fails to completely de colour.

RESULTS

ORANGE

Failed to de colour at 2.5cm3 of DCPIP

STRAWBERRY

Failed to de colour at 12cm3 of DCPIP

COURGETTE

Failed to de colour after 1cm3 of DCPIP

Comparison of all samples- Part 2

Method 2

Method is as before, and the equipment is the same, with the exception of the more highly diluted DCPIP solution.

RESULTS

VEGETABLES	RESULT
Potato	No colour change
Turnip	No colour change
Carrot	No colour change
Courgette	Initially no, but after standing time, turned colourless
Beans	No colour change
Tomato	Went colourless straight away

FRUIT	RESULT
Strawberry	Went colourless
Red Grape	Went purple/red
Apple	Went purple
Banana	Went dark purple
Orange	Went colourless
Pear	Went purple/red
Green Grape	Went purple

CONCLUSION
 During our experiment, we had certain levels of success. Certain fruits that we knew to be citric reacted extremely well, like Orange, which when exposed to DCPIP turned colourless straight away. Strawberry had the same result, and the courgette, after we left it standing for 5 minutes, also went colourless. Therefore, for the second stage of our investigation we will be looking at rough comparison of vitamin  C levels with the samples that worked today: The Orange, Strawberry, and perhaps surprisingly, the courgette.


REFLECTIONS
The changing of the solution concentration helped with several results, as did the refining of how long we left our samples after we had applied the DCPIP. We think that the experiments went well today, with some slight hiccups, and we worked well as a team.

Comparison of samples-Part 1

1. Equipment list:

• Test tubes
• Test tube rack
• Glass rod
• Spatula
• Pestle and Mortar
• Pipette
• Food samples
• Distilled water
• DCPIP solution ( 1gram DCPIP, 100ml Water)

1. Make an extract from the fruit/veg, using a pestle and mortar, to create enough to fill a test tube a 2/3 cm deep. Add to stand for a few moments.
2. Add a drop of the DCPIP solution, mix, and observe.
3. If the blue of the DCPIP disappears, Vitamin C is present.

RESULTS

FRUIT

Strawberry: DCPIP turned colourless

Red grape:DCPIP turned purple/red-Probable discolouration, no reaction?

Apple: DCPIP turned purple-Probable discolouration, no reaction?

Banana: DCPIP turned purple-Probable discolouration, no reaction?

Orange: DCPIP turned colourless

Pear: DCPIP turned purple-Probable discolouration, no reaction?

Green Grape: DCPIP turned purple-Probable discolouration, no reaction?

VEGETABLE

Potato: DCPIP did not change colour

Turnip: DCPIP did not change colour

Carrot: DCPIP changed to a lighter shade of blue-Probable discolouration, no reaction?

Courgette: DCPIP changed to a lighter shade of blue-Probable discolouration, no reaction?

Green Beans: DCPIP did not change colour

Tomato: DCPIP changed to be colourless.

REFLECTIONS

1. Mistook a evaporating plate for a pestle: Result was a broken evaporating plate.....
2. There was no/little colour change through most of the fruits/ Vegetables. WE expected ALL of samples to actually change, but we believe that there was no reaction between the DCPIP and the Vitamin C, hence the colour change was probably just discolouration.
3. We think that the DCPIP solution was probably too condensed, another reason for the lack of colour changes. We are therefore changing the condensation to 1 gram to 200ml of water.
4. The fruit will also be left for more than a minute, instead about two and a half.

Introduction

The theme for our group IV project this year is the Tour de France, the reason for this theme is because some of the opening stages are being held in Yorkshire before heading back over to France for the rest of the tour.

When our group got told the theme, we decided to look at health and food for the riders of the tour de France, we decided to look at the amount of vitamin C that is found in certain food the riders may come across while travelling across Yorkshire.

Health and diet is an essential part of any athletes life, and can be the difference between winning and losing. It is very important for the riders of the Tour de France to have a correct diet to replace all the carbohydrates, protein, vitamins and minerals lost during the previous stage.


Vitamin C is one of the most things to include in a regular diet. The powerful vitamin provides     

a number of very important health benefits, and the body needs it to function well. Vitamin C aids in staving off all kinds of diseases, improving the immune system, preventing inflammation, and supplying the body with chemicals that help it to process a diverse diet.



Health benefits of Vitamin C;

1. Contains antioxidants which help fight off free radicals in the body, warding off infections and virus - helping keep the riders of the Tour de France healthy during the Tour so there don't miss any stages.
2. It is useful at breaking down some kinds of oxidised fats
3. Helps build healthy tissue.