SCHOOL OF SCIENCE AND TECHNOLOGY, SINGAPORE
INVESTIGATIVE SKILLS IN SCIENCE
Names: Daris Ker & Augustine Yap
Group Reference: G
Group Project Proposal
Indicate the type of research that you are adopting:
[ X ] Test a hypothesis: Hypothesis-driven research
e.g. Investigation of the antibacterial effect of chrysanthemum
[ ] Measure a value: Experimental research (I)
e.g. Determination of the mass of Jupiter using planetary photography
[ ] Measure a function or relationship: Experimental research (II)
e.g. Investigation of the effect of temperature on the growth of crystals
[ ] Construct a model: Theoretical sciences and applied mathematics
e.g. Modeling of the cooling curve of naphthalene
[ ] Observational and exploratory research
e.g. Investigation of the soil quality in School of Science and Technology, Singapore
[ ] Improve a product or process: Industrial and applied research
e.g. Development of a SMART and GREEN energy system for households
An investigation on the treatment of vegetables on the concentration of Vitamin C.
Vitamin C present in Vegetables; How are we going to retain most of the Vitamin C contained in the Vegetable before we consume(The way we cook it/prepare it)
-Which type of vegetable is better for consumption in terms of Vitamin C?
-What role does Vitamin C play in the human body?
-What happens if a human has deficiency of Vitamin C?
-Are there side effects of too much Vitamin C?
-Which colour of vegetables contain more Vitamin C?
If I eat the Vegetable raw, then I’ll be getting the most vitamin C from it.
Questions to be Addressed
- How can we consume a vegetable with the most Vitamin C contained after some treatment to it(frying/steaming/boiling/microwaving).
- We have chosen the capsicum and cabbage as capsicums have some of the highest amounts of vitamin C among vegetables/fruits and vegetables and cabbages to have variety and are very easily obtainable.
- Vitamin C chemically decomposes under certain conditions, which may occur during the cooking of food. Vitamin C concentrations in various food substances decrease with time in proportion to the temperature they are stored at and cooking can reduce the Vitamin C content of vegetables by around 60% possibly due to increased enzymatic destruction as it may be more significant at sub-boiling temperatures. Longer cooking times also add to this effect.
- To solve the problem, we are going to try out 5 ways that are frequently used at home when cooking.
Ways we are treating the vegetables:
Fry, steam, boil, raw
According to some information, it would be better if we also did the testing on a light coloured vegetable. So we tested on Cabbages too.
-Type & Condition of water(Clear and of close temperature each time used)
-Type of Vegetables
- Ways we are preparing the Vegetables
-Colour of Resulting Liquid
- 5 Red Capsicums(Raw)
- 1 head of cabbage
-1 bottle of Diluted Iodine
- 1 frying pan(deep enough for boiling)
- 1 Steaming Rack
- 1 Juicer
- 2 set of 5 Boiling tubes with rack
- 1 Strainer
- 20 Pipettes (15ml/Standard)
- 1 Stirring Rod
Items we have to purchase/bring:
- 5 Red Capsicums
- 1 head of cabbage
- 1 Strainer
Preparing the Vegetables
- We will first treat the Vegetable first:
- Since vegetables are solid, we need to turn them into liquid first before we can use the indicator solution on it.
- Simply pulp each of the vegetables in a blender (remember to rinse the blender after each pulp to prevent contamination of results).
- Strain and keep the juices from the blending(5ml).
Testing the Vegetables
- With a dropper add 2ml of juice to a boiling tube, then add 2ml of the 1% starch solution. Add a drop of the iodine into the test tube each time until the colour turns blue-black. Record the number of drops of iodine required to see the uniform change in colour for all the juices.
- Clean the dropper and do the above for each juice sample.
- Record all the results and compare
- The one that contains the lesser number of drops of iodine when reacting, that vegetable contains the most amount of Vitamin C.
Repeat the steps for all the treated vegetables(Repeat entire procedures 4 times)
The more drops of iodine it takes for the solution to turn blue-black, the higher the concentration of vitamin C. (0.1% takes 28 drops)
Risk and Safety Assessment
As Induction plates are used, we have to be aware where is it and not get close to it.
As fire is used for frying, beware of fire and pay attention when frying.
Avoid eating the Capsicum(Leftovers).
1. Tabulate the data and calculate the average amount of the Vitamin C.
2. Plot a graph of the average amount of Vitamin C against the treatment of the vegetable.
3. From the graph, we can find out what way of preparing vegetables is the best for keeping in Vitamin C.
Brunilda (2011). How to keep nutrients in Vegetables. Retrieved 10,7,2014 from;
Condé Nast (2014). Foods highest in Vitamin C. Retrieved 10,7,2014 from;
Emily (2012). Copy of Science Project 2012. Retrieved 8,7,2014 from; http://prezi.com/edz6vykiy7jz/copy-of-science-project-2012/
Mossaguindo (2011). Are Dark Green, Leafy Veggies Higher in Vitamin C Content Than Their Lighter-Colored Counterparts?. Retrieved 9,7,2014 from; http://moussaguindo.wordpress.com/2011/12/14/are-dark-green-leafy-veggies-higher-in-vitamin-c-content-than-their-lighter-colored-counterparts/
Sofia PC(n.d). Are Dark Green, Leafy Veggies Higher in Vitamin C Content Than Their Lighter-Colored Counterparts?. Retrieved 8,7,2014 from; http://www.education.com/science-fair/article/dark-green-leafy-veggies-vitamin-c/
Wikipedia(2011). Vitamin C. Retrieved 16,7,2014 from; http://en.wikipedia.org/wiki/Vitamin_C