Extended Essay In Biology
Nutritional Content in Fruit Peels
To what extent is the nutritional content (L-ascorbic acid and riboflavin) in the peels of lemons (Citrus limon), oranges (Citrus sinensis) and pomegranates (Punica granatum) significant for consumption and which of the three fruit peels holds the highest Vitamin C and Vitamin B2 content?
Acknowledgements
I would like to thank Mrs. Soma Basu, my Extended Essay supervisor, for her constant support and useful advice on every aspect of the essay. I would also like to thank the laboratory technicians at school, Mr. Pandurang, Ms. Jyoti, Ms. Anju and Ms. Savita for aiding me along the way and helping me conduct my experiment in the best possible way. Table of Contents
Section 1: Introduction
1.1 Research Question
1.2 Theoretical Information
Section 2: Methodology
2.1 Pre-experimental Procedure
2.2 Experimental Procedure
Section 3: Data Collection and Analysis
3.1 Raw Data
3.1.1 Quantitative Data
3.1.2 Qualitative Observations
3.2 Data Processing
3.2.1 Vitamin C
3.2.2 Vitamin B2
3.3 Statistical Testing
3.3.1 Vitamin C
3.3.2 Vitamin B2
3.4 Graphical Representation and Analysis of Data
Section 4: Evaluation
Section 5: Conclusion
Bibliography
Appendix
Materials and Apparatus
Reference Graphs
Raw Data Tables
Pictures
Section 1: Introduction
1.1 Research Question
To what extent is the nutritional content (L-ascorbic acid and riboflavin) in the peels of lemons (Citrus limon), oranges (Citrus sinensis) and pomegranates (Punica granatum) significant for consumption and which of the three fruit peels holds the highest Vitamin C and Vitamin B2 content?
1.2 Theoretical Information
Vitamin C
Vitamin C, also known as L-ascorbic acid, is a water-soluble vitamin that aids in the biosynthesis of collagen, L-carnitine and specific neurotransmitters – dopamine, norepinephrine, epinephrine – in the body. Because, humans, unlike most animals, are unable to synthesise Vitamin C endogenously, it is important to incorporate it as part of our essential dietary component for daily intake. Collage is the most abundant protein in the human body. It is used to make skin, cartilage, tendons and blood vessels. It is an important component in connective tissues in the body and plays a vital role in would healing.
Vitamin C also acts as an antioxidant and has shown to be able to regenerate other antioxidants within the body, including alpha-tocopherol (Vitamin E). As an antioxidant, it is an electron donor it is a potent water soluble antioxidants and it is able to block some amount of damage caused by free radicals (molecule with single unpaired electron – highly reactive) that my cause damage to the DNA. The build of free radicals over time affects the ageing process and can affect the development of diseases like cancer and heart ailments.
Apart from its biosynthetic properties and antioxidant properties, the presence of Vitamin C also improves the absorption of nonheme iron (iron present in plant based foods).
Severe lack in consumption of Vitamin C causes the deficiency disease – scurvy. In the absence of Vitamin C the body produces lesser collagen, leading to the break down of tissues in the body and reduced production of neurotransmitters curricula for energy production in the body. The lack of Vitamin C produces symptoms like anaemia, myalgia, oedema, gum disease and poor wound healing in the early stages of the disease. This can further transcend in to severe jaundice, hemolysis, neuropathy, and convulsions.
To prevent deficiency diseases , the National Institute of Health (2011) published an average daily amount of Vitamin C to to be consumed for different ages:
Vitamin B2
Vitamin B2 is one of the 8 B vitamins, that helps to convert carbohydrates into glucose to produce energy. They also help metabolise fats and protein and are necessary for a healthy liver, skin, hair, and eyes. They aid the proper functioning of the nervous system as well. It is a water soluble vitamin, which means that our body does not store it.
Vitamin B2 is also called riboflavin. It works as an antioxidant, fighting damaging particles in the body called, free radicals. It participates in a range of redox reactions key to the function of aerobic reactions. It also helps the body activate Vitamin B6 and folic acid and, it is important for growth and the production of red blood cells. Riboflavin is also essential for normal vision, with studies suggesting that riboflavin may help prevent cataracts.
The lack of riboflavin can cause fatigue, slowed growth, digestive problems, cracks and sores around the mouth, swollen tongues, eye fatigue, sore throat and sensitivity to light. To prevent this, the best sources of riboflavin are almonds, organ meats, whole grains, wheat germ, wild rice, mushrooms, soybeans, milk, yogurt, eggs, broccoli, brussels sprouts and spinach.
Nutrition in India
In a country with a population of over 1.2 billion, around 21.9% of the population lives below the national poverty line. These people lack access to fresh sources of food on a daily basis and almost rarely eat a full square meal. This is what incubates the case of malnutrition. But, it’s not only the people under the poverty line that are suffering from malnutrition. With no proper balance in diet, countless others with good access to nutritious foods are also suffering from nutrient deficiencies.
Undernourishment can have serious consequences on the population of the country in the future. It causes inter-generational cycle of undernutrition, transmitted from mothers to their children, greatly impact the future of this country as undernourished children are more susceptible to diseases. Malnutrition also has repercussions on the socio-economic status of the country, leading to possible further widespread of poverty.
This malnutrition is constituent of undernourishment of any of the essential components of our diet, including fats, proteins, carbohydrates, vitamins or minerals. This means that coupled with lack of adequate food intake, even the absence of micronutrients (like the Vitamin C and Vitamin B2 that is going to be investigated in this experiment) from our diet can lead to undernourishment.
In publications that investigate dietary deficiencies, one such publication recorded that over 74% of the elderly population in North India and about 47% in South India, have insufficient intake of Vitamin C in their diets. Even in investigations for Vitamin B2, it has been found that in several age categories the percentage people that fall under the high risk criteria exceed 50%. This is only one example among countries other micronutrients that have high deficiency percentages in the Indian subcontinent. This means that the importance of these micronutrients in our diets is not widespread knowledge.
To combat this, the government and several nutritionists are working towards educating people about the importance of a well-rounded diet.
Food Wastes in India
Globally, over one third of all food produced for human consumption is wasted. This amounts to about 1.3 billion tons of food per year. This food is lost over every stage, right from the initial agricultural production, down to the final household consumption wastes.
In India, the issue of food waste is large. Up to 40% of the food produced in the country is wasted, which is close to a loss of 1 Lakh Crore Rupees every year. Not only is the unconsumed portion of the produced food in India part of this waste, even the scrap that is generated from the consumption of fruits and vegetables becomes a part of this waste. The food scrap is often buried in pits in rural villages and households because it is later used as compost for the plants. Recycling food wastes is also becoming more and more well known in the country. So, there are a lot of steps being taken towards the reduction of this waste production.
But, what if we are throwing away perfectly edible parts of the fruits and vegetables we consume? Parts such as the skin or the pericarp of fruits are often discarded because they are tough to consumer and are not very appetising. But, what if these peels contained nutrition that could actually help us as consumers, and all the poorer section of the society to use every bit of the food that they get to gain the maximum nutrition possible?
Fruit peel consumption has started gaining popularity over the past few years with companies releasing dried fruit peel powders for consumption. If these powders have significant nutrient contents, they can be used to supplement our diets and can add to the nutritional content of just the flesh of the fruit. Section 2: Methodology
2.1 Pre-experimental procedure
A. To prepare the fruit peel powder for the vitamin analysis
Peel the fruit, and preserve the pericarp of the fruit.
The remainder of the fruit ideally should not be discarded as that adds to the wastage of food. It should be consumed.
Divide the pericarp into smaller pieces.
This ensures faster drying when the peels are put in the oven.
Oven dry the pericarp at 110°C for 4-5 hours, until it develops a leathery texture and has shrivelled up.
Drying ensure the loss of moisture content in the peel and will enable the making of a finer and more consisted peel powder particle size. It will try to control all the possible variable associated with the presence of moisture in the peel.
Grind the peel into a powder using a mixer-grinder.
The grinder must not be overworked, as it can cause the burning or damaging of the peels. So, the grinding must be done periodically.
Sieve the obtained peel powder.
This will filter out any particle that is not uniform with the powder to ensure as much uniformity as possible with regards to the sample’s surface area and properties.
B. Preparation of oxalic acid – for Vitamin C test
Measure 0.4 grams of oxalic acid crystals using a weighing scale (± 0.01 grams).
Measure 100 cm3 of distilled water using a measuring cylinder (±0.1 cm3)
Add the oxalic acid to the the distilled water to create a 0.4% solution of oxalic acid.
The experimentation of was initially conducted with 2 other concentration but this concentration produced very distinguishable results (colour intensities).
C. Preparation of potassium permanganate solution – for Vitamin B2 test
Measure 5 grams of potassium permanganate crystals using a weighing scale (±0.01 grams).
Measure 100 cm3 of distilled water using a measuring cylinder (±0.1 cm3)
Add the measure mass of potassium permanganate to the distilled water to create a 5% solution of potassium permanganate
According to studies and previous experiments, the 5% potassium permanganate solution works best for the Vitamin B2 test.
2.2 Experimental Procedure
A. DCPIP test for the content of Vitamin C
Measure 0.25 grams of the peel sample using a weighing scale (±0.01 grams).
Macerate the sample with 6 millilitres of 0.4% oxalic acid and let it stand in the test tube for 45 minutes.
Oxalic acid has been studied to show very strong properties associated with maceration of plant cells. Maceration has to be performed so that the correct extracts can be analysed from the fruit peel samples.
Filter the solution using the simple filtration setup.
Basic filter paper, funnel and beaker setup.
Use 1 millilitre of the filter and 2 millilitre of 0.1% DCPIP solution in a cleaned cuvette.
Record the absorbance at 470 nanometre after 30 seconds.
Can be conducted at other wavelengths also.
Repeat procedure 10 times for all three fruit peels.
B. Test for the content of Vitamin B2
Measure 2.5 grams of the peel sample using a weighing scale (±0.01 grams).
Mix the solution with 10 millilitres of ethanol solution and let it stand in the test tube for 2 hours.
Riboflavin is one of the least water-soluble vitamins and therefore ethanol, an organic solvent in which it is more soluble is used.
Filter the extract using the simple filtration setup.
Basic filter paper, funnel and beaker setup.
Use 2 millilitres of the solution with 2 millilitres of 5% potassium permanganate solution and 2 millilitres of 30% hydrogen peroxide solution.
Allow the mixture to stand for 10 minutes in a water bath at 45°C.
Filter the resulting solution using the simple filtration setup.
Basic filter paper, funnel and beaker setup.
Record the absorbance of the solution at 470 nanometre after 30 seconds in a cleaned cuvette.
Can be conducted at other wavelengths also.
Repeat procedure 10 times for all three fruit peels. Section 3: Data Collection and Analysis
3.1 Raw Data
3.1.1 Quantitative Data
*See Appendix
3.1.2 Qualitative Observations
Figure 1: Shows the cuvettes after the addition of DCPIP for the three fruits
After adding the (deep blue) DCPIP solution to the fruit peel extracts for the determination of Vitamin C, it was noticed that the solution with the Citrus limon extract maintained an almost transparent solution, while the Punica granatum extract turned into light pink colour and the Citrus sinensis extract turned into a darker hue of pink.
Citrus limon
Citrus sinensis
Punica granatum
Figure 2: Shows the cuvettes after the chemical reactions for riboflavin for the three fruits
Before calculating the absorbance for the trials to calculate the riboflavin content, the three cuvettes looked almost identically transparent, which was a bit perplexing. But, on closer observation the solution for Citrus limon was clearer in comparison to the other two.
3.2 Data Processing
Data processing was conducted in two ways:
Mean
This is a basic statistical measure defined as an average value attained. In this investigation, the mean value was found for the vitamin content for each fruit peel sample. The mean value helps to compare the recorded data sets. It is given by the following formula:
where, refers to individual data points and refers to the sample size (10 data points in this experiment).
Standard Deviation
The standard deviation is a measure of the dispersion of a set of data points from its mean. A higher standard deviation value indicates a larger disparity/dispersion of data around the mean, and vice versa. The following formula has been inbuilt into the Apple Number application and was used for the calculation:
3.2.1 Vitamin C Test
3.2.2 Vitamin B2 Test
3.3 Statistical Testing
The one-way ANOVA test was used in this investigation. A one-way analysis of variance is used to determine whether that are any statistically significant difference between the means of two or more independent (unrelated) groups. The hypothesis for this test were formulated as:
Null hypothesis: Difference between the data sets are not significant
Alternate hypothesis: Difference between the data sets are significant.
If the determined p-value is less that 0.05, the means of the data is statistically significant and you can reject the null-hypothesis.
3.3.1 Vitamin C
The f-ratio value obtained is 129.8497 and the p-value is <0.00001.
The table above displays the result of the one-way ANOVA test and shows whether or not there is a statistically significant difference between the mean absorbance for the Vitamin C calculation of Citrus sinensis, Citrus limon and Punica Granatum. The ‘p-value’ obtained from the test is <0.00001 which is lesser than 0.05; the maximum p-value that shows statistically significant means. This means that the mean absorbance for each peel to calculate the Vitamin C content is statistically significant. Therefore the null hypothesis can be rejected.
3.3.2 Vitamin B2
The f-ratio vale is 4307.60537 and the p-value is <0.00001.
The table above displays the result of the one-way ANOVA test and shows whether or not there is a statistically significant difference between the mean absorbance for the Vitamin B2 calculation of Citrus sinensis, Citrus limon and Punica Granatum. The ‘p-value’ obtained from the test is <0.00001 which is lesser than 0.05; the maximum p-value that shows statistically significant means. This means that the mean absorbance for each peel to calculate the Vitamin B2 content is statistically significant. Therefore the null hypothesis can be rejected.
3.4 Graphical Representation and Analysis of Data
This graph assists us visually, to understand the difference in the absorbance of the DCPIP solution along with the fruit peel extracts of Orange (Citrus sinensis), Lemon (Citrus limon) and Pomegranate (Punica granatum).
The graph clearly shows which fruit peel powder had the most Vitamin C content and which had the least, as the fruit peel powder with the least absorbance shows the highest Vitamin C content as the solution is the most transparent when the absorbance is the lowest. The Citrus limon peel powder as the smallest bar and therefore is the fruit peel with the highest Vitamin C content with an absorbency of 0.279 au. Punica granatum has the second smallest bar and therefore has the second highest Vitamin C content with an absorbency of 0.443 au, and Citrus sinensis has the lowest vitamin C concentration with an absorbency of 0.571 au (in comparison to the other two fruit peel powders).
The error bars in Graph 1 do not overlap and therefore there is a very clear significance between the data points obtained through the experiment. However, since the graph is not a scatter plot, there is no trend line (line of best fit) and an r2 coefficient.
Using the regression curve formula from the graph obtained from secondary research, the approximate content of Vitamin C in the 2.5 gram sample of the dried fruit peel used can be calculated.
Sample calculation for Vitamin C content in Citrus sinensis:
Regression curve formula:
Therefore, using the mean absorbance value as 0.571 au, the “y” in the regression formula can be substituted with the absorbance value to find a corresponding vale of “x” or the ascorbic acid concentration.
This is gives us the concentration of 0.00186 M in the 1 millilitre sample analysis used in the colorimetric analysis. This means that proportionally, 1.87 x 10-7 mol of ascorbic acid is found in the sample. This is equivalent to approximately 3.28 x 10 -5 grams in 1 millilitre of sample.
Since, the total sample that was made of 2.5 grams was 6 millilitres, the amount of ascorbic acid in 2.5 grams is 1.97 x 10 -4 grams.
Similarly, the Vitamin C content was calculated for Citrus limon and Punica granatum.
Citrus limon = 2.97 x 10-4 grams
Punica granatum = 2.41 x 10-4 grams
This clearly shows that Citrus limon has the highest Vitamin C content, followed by Punica granatum and then Citrus sinensis.
Like Graph 1 for the solution with DCPIP, this graph helps us understand the difference in the absorbance of the solutions with the fruit peel extracts of Orange (Citrus sinensis), Lemon (Citrus limon) and Pomegranate (Punica granatum) treated with hydrogen peroxide and potassium permanganate.
The graph clearly shows which fruit peel powder had the most Vitamin B2 content and which had the least, as the fruit peel powder with the most absorbance shows the highest Vitamin B2 content according to secondary research. The Citrus limon peel powder as the smallest bar and therefore is the fruit peel with the lowest Vitamin B2 content with an absorbency of 0.804 au. Citrus sinensis has the second smallest bar and therefore has the second highest Vitamin B2 content with an absorbency of 1.109 au, and Punica granatum has the highest vitamin B2 concentration with an absorbency of 1.183 au (in comparison to the other two fruit peel powders).
The error bars in Graph 2 are extremely small and do not overlap and therefore there is a very clear significance between the data points obtained through the experiment and very little error in the collected data. However, since the graph is not a scatter plot, there is no trend line (line of best fit) and an r2 coefficient.
Using the regression curve formula from the graph obtained from secondary research, the approximate content of Vitamin B2 in the 2.5 gram sample of the dried fruit peel used can be calculated.
Sample calculation for Vitamin B2 content in Citrus sinensis:
Regression curve formula:
Therefore, using the mean absorbance value as 1.109 au, the “y” in the regression formula can be substituted with the absorbance value to find a corresponding vale of “x” or the riboflavin concentration.
This is gives us the concentration of 8.844 x 10-4 M in the 1ml sample analysis used in the colorimetric analysis. This means that proportionally, 8.844 x 10-7 mol of riboflavin is found in the sample. This is equivalent to approximately 3.329 x 10-4 grams in 1 millilitre of sample.
Since, the total sample that was made of 2.5 grams was 6 millilitres, the amount of ascorbic acid in 2.5 grams is 1.997 x 10-3 grams.
Similarly, the Vitamin B2 content was calculated for Citrus limon and Punica granatum.
Citrus limon = 1.447 x 10-3 grams
Punica granatum = 2.129 x 10-3 grams
This clearly shows that Punica granatum has the highest Vitamin B2 content, followed by Citrus sinensis and then Citrus limon.
Section 4: Evaluation
Methodology and Experimentation
For the experimentation, the fruit peel samples were oven-dried under low heat and for a long duration to ensure that the peels do not burn. Ideally, the fruit peels could have been sun dried. But, the weather conditions during the time period of the experimentation, did not support the method of natural drying. So, for a more accurate determination of the contents of the fruit peel, the peel could have been sun-dried as this helps to ensure that no section of the peel that is being analysed has been charred.
Also, during the analysis the moisture content of the fruit peels was not taken into consideration as the level of moisture left after drying in the peel of Citrus sinensis may not have been the same as in the Citrus limon or Punica granatum peels.
Another limitation of the experiment is associated with any presence of fingerprints on the cuvette used in the colorimeter. Although a lot of care was taken in making sure that dry and clean cuvettes where used for the analysis, this could have interfered and caused the minor anomalies in the data collected.
For the measurement of absorption at particular wavelengths, during my research, I found that the most ideal wavelength for each vitamin was one that could not be calibrated on the colorimeter at hand. Instead, I had to use the wavelength that was closest to the most efficient wavelength for the determination of the vitamin content. Any error produced by this can be eliminated by using a more accurate apparatus, such as a photo-spectrometer, which would give more accurate absorbency values and results.
But, throughout the experimentation, all the possible variables except for the identified dependent variable was controlled, including the room temperature, temperature of the water bath used, concentration of the reagents, mass of the trial samples for experimentation and duration of experimentation for each trial.
Statistical Testing and Data Errors
In this experiment, the one-way ANOVA test was used to statistically evaluate the significance of the means obtained. The test is generally used when there are 2 or more variable, in this experiment, 3 fruit peels. The test was used to determine if the mean value of the absorbance of the treated fruit peel extract solutions for vitamin analysis was significant. Here, since the “p-value” obtained through the testing was <0.0001, which is lesser than 0.005, the values where significant and the statistic rejected the null hypothesis and supported the alternate hypothesis.
But, the one-way ANOVA test is based on assumptions which may decrease the reliability of the reading:
The dependent variable is normally distributed in each group that is being compared in the one-way ANOVA. (A normal distribution is where the probability distribution plots all the values in a symmetrical fashion, mostly situated around the probability’s mean). This means that the data should not have outliers.
There is homogeneity of variances. The population variances in each group are equal.
In this experiment, there were no real outliers (very minor anomalies in 2 data groups), mostly satisfying the assumption of the normal distribution. But, the variances (square of standard deviation) were not homogeneous, which could have lead to an inaccuracy in the testing. Therefore, to improve the accuracy of the experiment, the number of trials per fruit peel/ the sample size for testing can be increased, resulting in data that can be more accurately characterised as a normally distributed population and a reduction in the variance in the trials.
The increase in the number of trials can also reduce the random errors associated with the experiment, which can be seen through the absence of a mode in any data group (all data points were unique).
Results
Because of the lack of literature values, the experimental values cannot be compared to any investigation that has been already performed. Only one source of value was found for the Vitamin C content for the peel of Citrus limon and Citrus sinensis. According to the source, 6 grams of a raw Citrus limon peel contains 7.7 milligrams of Vitamin C while Citrus sinensis contains 8.2 milligrams of Vitamin C in its peel. When compared to the data processed in this experiment, the values obtained through the experiment when extrapolated to 6 grams of sample are significantly lower than the literature data. Also, the value for Citrus sinensis in comparison to Citrus limon was lower, which refute the literature values. This could be due to the presence of any human error during the experimentation. Also the drying of the peels that was conducted prior to the experiment could have contributed to the error involved in the data. Because Vitamin C is a water soluble nutrient, there are possibilities that the drying had effects on the vitamin contents of the samples.
Further Scope
The experiment can be conducted on a wide range of fruits and vegetables, analysing more types of nutrients that was not analysed in this experiment due to the lack of access to necessary equipment. A further analysis under more controlled environments can help determine which fruits and vegetable skins should actually be consumed for added nutrition.
Section 5: Conclusion
The aim of this experiment was to investigate whether the fruit peels of commonly consumed fruits in India contain micronutrients that can help supplement diet while consuming, so as to utilise available to food to their maximum potentials. For this, two separate investigations were conducted. One for the colorimetric determination of Vitamin C content and the other for the determination of Vitamin B2 content.
Looking at Table 1, the mean absorbance for Citrus sinensis (sweet orange), Citrus limon (lemon) and Punica granatum (pomegranate) is 0.571 au, 0.279 au and 0.443 au, respectively. Showing that all three fruit peels do contain some amount of Vitamin C in them. When analysed for the Vitamin C content, it was found that the solution with the least absorbance, the solution for Citrus limon, at 0.279 au, had the highest Vitamin C content. There was 0.297 milligrams of Vitamin C in the dried 2.5 gram sample of the fruit. Punica granatum had the second highest Vitamin C content with 0.241 milligrams while Citrus sinensis had 0.197 milligrams in the sample. This trend could be predicted by looking at the reaction of DCPIP with the solutions as well, because DCPIP is a reagent that is known to give results for the Vitamin C content in solution. It acts as an indicator that turns colourless in the presence of Vitamin C. Looking at Figure 1, this trend in the Vitamin C content could be predicted: the pink colour of the solution darkened, the Vitamin C content decreased.
Looking at Table 2, the average absorbance after a treatment of the fruit peel solutions with hydrogen peroxide and potassium permanganate was 1.109 au, 0.804 au and 1.183 au for Citrus sinensis, Citrus limon and Punica granatum, respectively. When analyse for the Vitamin B2 content, it was found that the solution with the most absorbance had the highest vitamin content, giving us the results for the vitamin content as 1.997 milligrams in Citrus sinensis, 1.447 milligrams in Citrus limon and 2.129 milligrams in Punica granatum (in the 2.5 gram samples of their peels). So, according to this trend, Punica granatum had the highest Vitamin B2 content in the experiment. What was interesting was that even though (as seen in Figure 2) the solutions post-filtration in the cuvettes looked transparent, and similar in terms of physical properties, each solution had a different absorbance, giving different Vitamin B2 contents in each fruit.
For this experiment, it was found that there is a lack of literature values to compare the experimental values with to test for accuracy. Although dried fruit peels are available in the market nowadays for consumption, further experimentation can be conducted to actually mark out the significance of consuming the fruit peels.
From this experimentation, a conclusion can therefore be drawn, stating that, the pericarp/ the peels of fruits that we consume do have nutritional content and can be consumed in their dried for to add to the nutritional benefits we gain from their pulp.
Bibliography Appendix
I. Materials
For 10 trials of one type of fruit peal, for example, Citrus limon
Apparatus:
1 Colorimeter (± 0.001 units)
10 Boiling tubes
10 Test tubes
10 Filter paper
1 Weighing scale
3 Measuring cylinders – 10 cm3, 100 cm3
2 Pipettes
3 Dropper
1 Cuvette
1 Spatula
1 Stop watch
1 Petri dish
10 Beakers – 50 cm3
10 Funnels
Water bath
Chemicals and Reagents:
Oxalic acid crystals
0.1% DCPIP solution
Ethanol solution
Potassium permanganate
Distilled water
II. Reference Graphs
Graph A: Riboflavin absorbance graph
https://www.hindawi.com/journals/isrn/
2014/453085/
Graph B: Ascorbic acid absorbance graph
http://www.sciencedirect.com/science/article/
pii/S1631074817301583
2014/453085/
III. Raw Data Tables
IV. Pictures
Figure 3: Fruit peel powders in oxalic acid solution
Figure 7: Punica granatum peel powder in ethanol
Figure 5: Fruit peel extract solutions after reacting with potassium permanganate and hydrogen peroxide
Figure 4: Filtration of fruit peel powder in oxalic acid
Figure 6: Filtration of fruit peel powder in ethanol