Introduction:
Vitamin C, also known as ascorbic acid is an acid found is various foods. The acid is essential that helps your body function in a variety of ways these include promoting bone health, reducing inflammation and boosting the immunity (which is why vitamin c is good for colds).
Research has found that there is not a significant difference in the amount of nutrients in organic and non-organic fruit and vegetables from the many studies conducted scientists have not proven reasons only theory’s behind why organic produce may have more nutrients than conventical.
The only certain difference between organic and conventical produce is what the fruits and vegetables are grown with. Conventical which is grown with pesticides and fertiliser (Chemicals that can be toxic) and organic which are not grown with chemicals (There grown with other types of fertilizer e.g. manure), which is the main reason behind why people buy organic produce.
A study that was conducted by Saarang Mulukulta found that there was a comparable difference in organic and conventical produce the fruits that showed a substantial difference was lemon and kiwi fruit. Another study conducted by Kane S found that there was 0.9g more vitamin c in organic broccoli than conventical but it is not a vast difference to make a impact in people’s health.
A theory that has not been enforced for why organic fruits and vegetables have more vitamins and antioxidants. That plants produce chemicals (vitamins) as a protective mechanism in response to environmental stressors, an example of an environmental stressor are insects because they threaten the survival of plants. When people spray pesticides, plants are not exposed to these natural stressors since the chemical sprays get rid of bugs and insects, which means the plants do not need to produce the chemicals (vitamins) which leads to less vitamins. In response to the theory researchers have found that there is not a comparable difference in nutrients in organic and conventical produce meaning that there is a difference.
Even though many studies have shown that there is a difference in vitamin C it is not higher enough to make a comparable difference in someone’s health which is why people could be another reason why people purchase organic produce.
Glossary:
Conventical:
Produce that is farmed with unnatural fertilizer and pesticides
Pesticides:
a substance used for destroying insects or other organisms harmful to cultivated plants or to animals.
Organic:
(of food or farming methods) produced or involving production without the use of chemical fertilizers, pesticides, or other artificial chemicals.
Natural stressors:
Stressors are environmental factors that cause stress. They include biotic factors such as food availability, the presence of predators, infection with pathogenic organisms or interactions with conspecifics, as well as abiotic factors such as temperature, water availability and toxicants
Fertilizer:
a chemical or natural substance added to soil or land to increase its fertility
Scurvy:
a disease caused by a deficiency of vitamin C, characterized by swollen bleeding gums and the opening of previously healed wounds.
Manure:
animal dung used for fertilizing land
Aim:
To discover if there is a higher mass of vitamin c in organic or non-organic fruits and vegetables containing vitamin C.
Hypothesis:
That organic fruit and vegetables with vitamin C will have a higher mass of vitamin c than conventical produce.
Risk assessment:
Identity Risk Assess risk Control risk
Burning from boiling water Likelihood: Low to moderate
Severity: Low to moderate To control this risk, I will make sure that I am wear appropriate clothing that does not show skin and that I am wearing heat proof gloves.
Getting acid (citric acid- oranges) in eyes from produce Likelihood: Low
Severity: Moderate Wear protective eyewear
Cutting fingers/hands when grating fruit Likelihood: Moderate to high
Severity: Moderate to high Wear protective gloves when grating and cutting fruit
Method:
1. Buy produce containing vitamin C from 1 selected store (e.g. Woolworths) resulting in the same quality of produce
2. Ensure the date fruit was picked around the same week
3. Make a paste solution with corn flour (2 teaspoons of corn flour- 200ml of water) – Mix with cups of boiling to hot water
4. Stir until thoroughly mixed (Paste consistency)
5. Let solution cool in a refrigerator (Time for 2 mins on iPhone)
6. Cut up 10g of selected fruit/vegetable and weigh on kitchen scales to ensure accuracy
7. Grind or grate 10g of selected produce
8. Add 100ml of water to wash out grinder/grater
9. Add the solution (water and fruit) to a glass or plastic cup
10. Add 5ml of corn solution with a syringe
11. Stir with spoon for 1 minute
12. Place strainer on top of new glass cup
13. Transfer solution (Water, fruit and corn starch) into a new cup with strainer
14. Use eye dropper to count how many drops of iodine there is
15. Stop counting when solution is- greyish blueish
16. Record number of drops was needed for the starch to react
17. Repeat these steps at least 3 times for reliability and accuracy
Photograph of setup:
Type of produce Mass of vitamin C- Titration
Trial 1 Trial 2 Trial 3 Trial 4 Average
Organic Capsicum 2.9 1.8 4.2 1.4 2.575
Capsicum 2.8 1.8 2.1 1.4 2.025
Organic Oranges 1.5 1.4 1.3 1.4 1.4
Oranges 0.8 1.2 0.9 1.5 1.1
Organic Kiwi 1 1.4 1.3 1.5 1.3
Kiwi 1.2 0.7 0.9 0.8 0.9
Organic Apple 2 1.8 1.6 1.7 1.775
Apple 1.8 0.9 0.8 0.6 0.775
Amount found of vitamin C by titration in organic vs. conventical produce
Discussion
Analysis:
The results have shown that organic fruit does have a higher level of vitamin C than conventical produce. All results support the hypothesis which displays higher levels of iodine which means there are higher amounts of vitamin C. The common trend shown in all produce experimented was that organic does have higher levels of vitamin c than conventical. In not one of the averages was there a higher level of vitamin C in conventical than organic. This supports the hypothesis that organic fruit does have more vitamin C than conventical. A Trend that was shown in the graph and table was that fruits that are ‘known’ for having vitamin C ( e.g. Oranges & kiwi) had a low vitamin C mass compared to produce that is not known for having high amounts of vitamin C.
Explanation of results:
In the results organic produce has more vitamin C than conventical which compliments the theory that organic produce has more vitamin C than conventical. The Organic produce has more Vitamin C than conventical since it is not getting sprayed with presides or is grown with unnatural fertiliser meaning that it produces more chemicals than conventical hence it is trying to protect its self against natural stressors. When using solution to test mass of vitamin C (Iodine + ascorbic acid +corn starch) the iodine and ascorbic acid causes another solution (dehydroascorbic acid) which does not have vitamin C after there is no vitamin C left for the iodine to react with it then reacts with the starch thus the colour change. Which means if there is more vitamin C in the produce then it will take longer to react with the starch which means there will be more drops of iodine (which means higher level of vitamin C) until the iodine and starch react which causes a colour change (blueish-purplish-greyish).
Accuracy:
In the experiment the measurements were accurate since it was a control variable that was important in keeping my experiment accurate and reliable. The accuracy of the amount of iodine could have been more consistent which could be improved by measuring it (e.g. 5 g per drop) which would make it more reliable than a human dropping drops.
Validity:
The validity of the method was valid and controlled because I controlled all of my controlled variables resulting in a valid experiment. For example, the fruit was cut to 10g which makes it valid and controlled hence higher weight leads to higher mass of vitamin C. Another reason that the experiment was valid was because I controlled where they were grown (e.g. both organic and conventical apples were grown in Australia)
Reliability:
The results are reliable since I controlled all variables that disguise a reliable experiment, I was also consistent and make sure all variables were controlled before I conducted my experiment. The reliability could be improved by doing more trials which would make the results more reliable.
Follow up research:
Based off the results, some follow up research that would be fascinating to research is how plants produce vitamins (in depth). Another topic that would be fascinating is why specific fruits have more vitamin C (e.g. plants that grow in harsh conditions-windy, have insects etc. leading to them producing more chemicals (vitamins) to protect themselves against natural stressors). Another topic I would like to investigate next time if I had the opportunity is titration and why vitamin C runs out before iodine (maybe because one is stronger – particles denser)
Application of these results:
The experiment I conducted is very beneficial to society since many people pay extensive amounts for organic produce, even though many buy produce mainly because it does not have chemicals like conventional produce but many also believe that organic produce has more nutrients (vitamins) than conventical since the high cost. It is also beneficial to know if there are more vitamins in organic produce since it is an easy way of boosting your immune system and adding extra vitamins into your diet for an extra cost.
Conclusion:
The Aim of this experiment was to discover if there is more vitamin c in organic or non-organic fruits and vegetables. The results show that organic fruit does have higher levels of vitamin c than conventical produce which accepts the hypothesis that organic does have higher levels of vitamin c.
References
Charles. D (July 11, 2014) Are organic vegetables more nutritious anyway? National Public Radio
Retrieved from:
https://www.npr.org/sections/thesalt/2014/07/11/330760923/are-organic-vegetables-more-nutritious-after-all
Determination of vitamin C concentration by titration. Canterbury (Date not recorded)
Retrieved from:
https://www.canterbury.ac.nz/media/documents/science-outreach/vitaminc_iodine.pdf
Measuring vitamin C in food- Global experiment (30 October 2013)
Retrieved From:
(P. Rea, personal communication – naturopath, (7 August 2018))
Zukerman. W (3 September 2016) Science vs. organic: Is it really good for you? News
Retrieved from:
https://www.news.com.au/lifestyle/health/diet/science-vs-organic-food-is-it-really-any-better-for-you/news-story/27e0a58c3abef252b8fc7aa7eddfa5e9