Effect Of Boiling On The Vitamin C Biology Essay

Effect Of Boiling On The Vitamin C Biology EssayAbstractThis test was designed to investigate the effect of stewing on the vitamin C surfeit of selected ve bestowables ( bitter gourd, broccoli, dough, cauliflower, green capsicum, sweet peas, long beans and tomato). Vegetables were turn for 10 minutes. The juices of both dim and boiled vegs were extracted and titrated with 1 cm3 of 0.1% DCPIP resolve. The pile of severally juice infallible to decolourise the DCPIP settlement was sumd and the vitamin C subject matter was determined. The comparable procedure was restate with new(prenominal) types of vegetables. The statistical t-test (paired sample) showed that the vitamin C content of raw vegetables is signifi fecal mattertly higher(prenominal) than that of boiled vegetables. The results support the hypothesis boil reduces the vitamin C content of vegetables.accumulative sacred scripture depend one hundred thirty-fiveResearch and RationaleVitamin C is needed for growth, the healings of wounds, and the repair and maintenance of cartilage, bones and teeth. It is essential in the formation of collagen, a structural protein needed in the deductive reasoning of skin, scar tissue, tendons, ligaments and blood vessels.1The antioxidant activity of vitamin C reduces the damage ca subroutined by free radicals, which contribute to aging, undersidecer, heart disease and inflammatory conditions.2Vitamin C improves resistance to infection and reduces the risk of infection of cardiovascular diseases by raising the level of blood high-density lipoproteins (HDL) cholesterol.34The Recommended Dietary each(prenominal)owance (RDA) of vitamin C is approximately 90mg for men and 75mg for women.2 Vitamin C must be consumed by dint of our diet because it is not stored in our body. Since it is peeing soluble, excessive amounts of vitamin C are excreted via urine.1 Deficiency in vitamin C can lead to scurvy.5Sources of vitamin C include citrous fruit fruits an d fresh vegetables.6 additive playscript count 337The main biologically active form of vitamin C is ascorbic acid. In this experiment, the presence of ascorbic acid is indicated by a oxidation-reduction dye, DCPIP (2,6-dichloroindophenol).7DCPIP reacts with ascorbic acid in a 11 ratio. Ascorbic acid, be a reducing agent, reduces the DCPIP, while ascorbic acid itself is oxidised to dehydroascorbic acid.Ascorbic acid Dehydroascorbic acidDCPIP (blue) Reduced DCPIP (Colourless) forecast 1 The oxidation of ascorbic acid and reduction of DCPIP8The end-point of this DCPIP titration is when the blue colour of DCPIP disappears, forming a colourless source which persists for 10 seconds or to a greater extent.8 This method is chosen because DCPIP is less toxic. It is sour that the vegetable tissue component which reduces the DCPIP rapidly is vitamin C.Cumulative word count 495Traditionally, vegetables are cooked to destroy germs, to soften the food so that it can be substantially digested , to make them look attractive and to enhance the taste.91011However, the stability of vitamin C is affected by exposure to air or light, presence of metals or heat energy and alkalinity. Marzena et al (2007) reported that simmering ca employ a reduction in vitamin C content (3.68 mg/100g in potatoes and 2.38mg/100g in carrots)12.This experiment was aimed to compare the vitamin C content of raw and boiled vegetables, thus determining the best method of consuming them so that the intake of vitamin C is maximised. Vegetables selected are those which are eaten raw or later being boiled by Malaysians. Vegetables such as broccoli and green pepper were selected because of their high vitamin C content so that the loss of vitamin C during simmering is more significant.Furthermore, the vitamin C content of cookery water system of broccoli, cauliflower, swag and tomato were also determined to identify whether the vitamin C content was confounded due to heat from boiling or leaching into the readying water. These vegetables were chosen because they are the typical ingredients to make vegetable soup.Some people rarely eat raw vegetables.1314The results from this experiment can be utilise as evidence that eating fresh, raw vegetables are healthier as they contain more nutritional values. Consuming boiled vegetables whitethorn result in a lower intake of vitamin C because the water used for boiling is usually discarded. Thus, it may also be advisable to use the preparation water as a soup base to prevent wastage of vitamin C.Cumulative word count 855Experimental HypothesisThe vitamin C content of the raw vegetables is significantly higher than that of boiled vegetables.Null HypothesisThere is no significant difference between the vitamin C content of raw and boiled vegetables.VariablesManipulated asseverate of vegetables (raw, boiled)Responding peck of vegetable juice needed to decolourise 1cm3 DCPIP solutionFixed Type and meanness of vegetable juice, length of e xposure to air after mix the juice, mass of 0.1% DCPIP solution, standard vitamin C solution, boiling time and amount of water used for boiling.ApparatusTest pipes, test tube rack, 500ml volumetric flask, pipette (to measure accurately to 1cm3), burette, pestle and mortar, measuring balance, glass rod, 200ml beaker, blender, a stainless steel pot and stove.Materials0.1% DCPIP solution, vitamin C tablet, distilled water, muslin cloth and eight polar types of vegetables listed in Table 5.Cumulative word count 995PlanningA trial experiment was conducted using cabbage to determine the most suitable method of manipulating the variable. The vitamin C was extracted by blending 100g cabbage in 100ml distilled water using a commercial blender. The juice extracted was then boiled for 10 minutes. Anformer(a) 100g of cabbage was boiled in 100ml cooking water for the same period of time. The boiled cabbage was blended to extract its juice. The control experiment was carried out using raw cab bage juice.CabbageVolume of cabbage juice needed to decolourise 1 cm3 DCPIP solution (ml)Raw9.70Blended, then boiled11.30Boiled, then blended15.75Table 1 Results for the different methods used to determine the volume of juice neededThe results show that boiling the cabbage before blending it had the most significant effect on the vitamin C content. Besides, this is the customary way of cooking. Thus, the method of boiling before blending was used.The ratio of cabbage to cooking water to be used was identified. 100g of cabbage was added to either 100ml (11 ratio) or 200ml (12 ratios) distilled water and boiled.CabbageCabbage to cooking water ratioVolume of juice needed (ml)Raw9.70Boiled111213.6515.85Table 2 The volume of cabbage juice needed with respect to different cabbage to cooking water ratioBased on table 2, when a ratio of 11 was used, the difference in volume of juice was small. Thus, the cabbage to water ratio was changed to 12 so that the effect was more significant.Cumula tive word count 1251The most suitable concentration of DCPIP solution to be used was determined. 0.1g of DCPIP was fade out in either 100ml or 10ml distilled water.Volume of distilled water (ml)Concentration of DCPIP solution (%)Volume of cabbage juice needed (ml)RawBoiled1000.19.715.7101.034.654.0Table 3 The volume of cabbage juices needed to decolourise 1 cm3 DCPIP solution with respect to different concentration of DCPIP solutionDCPIP solution of concentration 0.1% was used because a smaller volume of cabbage juice is needed to decolourise the DCPIP solution. This makes the procedure easier and shortens the experimental time.Cumulative word count 1354Real Experimental ProceduresI Preparing standard vitamin C solutionA vitamin C tablet was crushed into fine powder with a pestle and mortar.62.5mg of the vitamin C powder was weighed using a measuring balance. The powder was dissolved in a 200ml beaker by adding 10ml portions of distilled water. The solution was stirred using a glas s rod.The solution was transferred into a 500ml volumetric flask. The beaker and glass rod were rinsed with successive portions of distilled water and the washings was transferred into the flask. The solution was made up to mark using a dropper.The solution is now exactly 0.125 mg of ascorbic acid per cm3 of solution.Steps 2 to 4 were repeated to prepare different concentrations of vitamin C solution listed in Table 4 using different amounts of vitamin C powder.II Preparing standard curve of vitamin C1cm3 of 0.1% DCPIP solution was pipette into a test tube.A burette was filled with 0.125 mg cm-3 vitamin C solution.The vitamin C solution was added drop by drop into the test tube containing DCPIP solution until the blue DCPIP decolourises. The tube was shaken gently after each drop. The volume of vitamin C solution needed was measured.The procedure was repeated twice to get an average titre.Steps 1 to 4 were repeated using vitamin C solution of concentrations listed in Table 4.A stand ard vitamin C curve (Graph 1) was plot based on the result.Cumulative word count 1608III Identifying the vitamin C content of raw and boiled vegetablesThe non-edible parts of a bitter gourd were run intod.100g of bitter gourd was blended in 100ml distilled water using a commercial blender and was filtered using a muslin cloth.The volume of the freshly extracted vegetable juice needed to decolourise the DCPIP solution was determined using steps 1 to 4 in Experiment II.100g of bitter guard was boiled for 10 minutes in 200ml boiling water using a 5-inch-deep stainless steel pot.After 10 minutes, the boiled bitter gourd was immediately removed from the cooking water and cooled by immersing in an ice-cold water bath for 5 minutes.Steps 2 and 3 were repeated using the boiled vegetables.This experiment was repeated with the other vegetables listed in Table 5.The vitamin C content of all vegetables was deliberate using the standard vitamin C curve.The data of volume needed and vitamin C c ontent were tabulated.A graph of vitamin C content of raw and boiled vegetables was plotted.A t-test was used to statistically analyse the data.IV Identifying how vitamin C is lossThe cooking water of broccoli, cabbage, cauliflower and tomato was collected.200ml distilled water was added to the cooking water. It was cooled by immersing in an ice-cold water bath for 5 minutes.Steps 1 to 4 in Experiment II and steps 8 and 9 in Experiment III were repeated using the cooking water.The difference between vitamin C content of vegetables before and after boiling (inclusive of its cooking water) was calculated.A graph of vitamin C content of cooking water was plotted.Cumulative word count 1895Safety PrecautionsHeat resistant gloves were languid when dealing with boiled vegetables.Laboratory coat and goggles were worn to prevent the DCPIP solution and vitamin C solution or vegetable juices from staining the clothes or skin, or getting into the eyes.All glasswares such as test tubes, pipette and beakers were handled with extra conduct since the apparatus could break easily and cause injury.When using the burette, care must be taken to ensure that no air bubbles were trapped at the jet which may affect the accuracy of the titre.Cumulative word count 1990ResultsI Preparing standard vitamin C solutionMass of vitamin C powder (mg)Concentration of Vitamin C solution (mg cm-3)Volume of vitamin C solution (ml)123 second-rate62.50.12510.3010.2010.2010.20125.00.2505.205.205.155.20187.50.3754.004.054.004.00250.00.5002.903.003.003.00312.50.6251.801.801.801.80375.00.7501.401.351.501.40Table 4 The mass of vitamin C powder needed for serial dilution and the volume of vitamin C solution needed to decolourise 1 cm3 DCPIP solutionCumulative word count 2082II Standard Vitamin C curveCumulative word count 2133Graph 1 Graph of volume of vitamin C solution needed to decolourise 1 cm3 of 0.1% DCPIP solution against concentration of Vitamin CIII Calculating the vitamin C content of raw and boiled vegetablesFrom graph 1, vitamin C solution is needed to decolourise 1 cm3 0.1% DCPIP solution.Using the formulawherev = Volume of vitamin C solution needed to decolourise the DCPIP solutionc = concentration of vitamin C solutionk = constantIt can be derived thatThus, the vitamin C content of vegetables, c can be calculated byCumulative word count 2219Types of vegetablesVolume needed to decolourise 1cm3 0.1% DCPIP solution (ml)Raw vegetablesBoiled Vegetables123Average123AverageBitter gourd2.402.552.452.504.204.054.104.10broccoli4.254.204.154.206.206.156.206.20Cabbage9.709.559.609.6015.6015.8015.7515.70Cauliflower2.852.852.652.803.653.653.753.70Green pepper1.201.051.301.203.503.403.603.50Sweet peas4.254.404.254.309.009.008.808.90 longsighted beans13.0013.0012.9013.0021.0021.2020.9021.00Tomato0.550.700.600.601.852.001.901.90Table 5 Volume of juices needed for different types of raw and boiled vegetablesTypes of vegetablesVitamin C content (mg cm-3)Raw vegetablesBoiled Vegetables Bitter gourdBroccoliCabbageCauliflowerGreen pepperSweet peasLong beansTomatoCumulative word count 2387Table 6 Vitamin C content of raw and boiled vegetablesCumulative word count 2430Figure 2 Bar map of vitamin C content of raw and boiled vegetablesIV Identifying how vitamin C is lossCooking waterVolume needed to decolourise 1cm3 0.1% DCPIP solution (ml)Vitamin C content (mg cm-3)123AverageBroccoli13.2013.0013.1513.10Cabbage15.2015.2015.0015.10Cauliflower15.7015.8515.8015.80Tomato9.459.509.509.50Table 7 The vitamin C content of cooking waterTypes of VegetablesVitamin C content (mg cm-3)Before boilingAfter boilingDifference= Before After (Raw Total)RawBoiledCooking waterTotal(Boiled + Cooking water)Broccoli0.4277-0.0009Cabbage0.23350.0460Cauliflower0.6004-0.0425Tomato1.1369-1.8631Cumulative word count 2553Table 8 Difference in total vitamin C content before and after boilingCumulative word count 2598Figure 3 Bar chart of vitamin C content of cooking waterStatistical AnalysisThe pai red sample t-test was used to analyse the data.Types of vegetablesVitamin C content (mg cm-3)Difference, d = Raw BoiledRawBoiledBitter gourd0.72000.43900.2810Broccoli0.42860.29030.1383Cabbage0.18750.11460.0729Cauliflower0.64290.48650.1564Green pepper1.50000.51430.9857Sweet peas0.41860.20220.2164Long beans0.13850.08570.0528Tomato3.00000.94742.0526Table 7 Difference in vitamin C content of raw and boiled vegetablesCumulative word count 2735The calculated t-value (2.005) shows it is significant whereby it exceeds the tabulated t-value, which is 1.895 (pData AnalysisThe vitamin C content of raw vegetables is on average 0.4945 mg cm-3 higher than that of boiled vegetables. The percentage loss of vitamin C during boiling is 56.22%. Error bars displayed on Figure 2 represent the overall distribution of the data. Upper error bar for boiled vegetables does not overlap the clasp of value within error bar of raw vegetables. Thus, these two vitamin C content values differ significantly.Figure 2 shows that raw vegetables come higher vitamin C content than boiled vegetables, suggesting that it is best to eat raw vegetables rather than those boiled. Nevertheless, if vegetables were to be boiled, it is advisable to serve the vegetables with the cooking water since vitamin C is found in the cooking water after boiling (Figure 3).Cumulative word count 2865Boiling breaks down the cell wall of vegetables, causing their permeability to increase. Vitamin C, being water-soluble, leaches into the cooking water. This agrees with the data in Table 7 as vitamin C is found in the cooking water after boiling. The vitamin C is lost as the cooking water is discarded.15The reduction in vitamin C content of vegetables (including their cooking water) after boiling as shown in Table 8 agrees with the suggestion that vitamin C is lost due to thermal degradation.1617The high temperature of boiling water increases the rate of oxidation of L-ascorbic acid to L-dehydroascorbic acid. L-dehydroasco rbic acid, being unstable, tends to undergo hydrolysis to form diketogulonic acid, a physiologically inactive compound. This suggests that heat produced during boiling can cause vitamin loss.Figure 4 The destruction of vitamin C18Burg Fraile (1995) reported that vitamin C can also be destroyed by enzymatic destruction and enzyme thermal deactivation reactions during home cooking.1920Cumulative word count 3123However, the results differ for cabbage. Unlike the other three vegetables, the total vitamin C content of cabbage after boiling is 0.0460 mg cm-3 higher than that of raw cabbage. This may be due to the more complete extraction of juice as the cabbage tissue is softer after boiling.The results of my investigation are supported by a previous investigation by Podsedek A. et al (2007) on two varieties of red cabbage Koda and Kissendrup. The vitamin C content of vegetables decreased after boiling.21Cooking methodCooking time (min)Vegetable water (g/ml)KodaKissendrupVitamin C conte nt (mg/100g)Raw cabbage72.5662.00In boiling water201223.7426.77201133.6138.36101131.7438.72Table 8 The effect of boiling on the vitamin C content of red cabbageMoreover, Carol Reiss (1993) reported an average of 21.75mg/100g ascorbic acid in the cooking water after boiling a cabbage. This agrees with my results that vitamin C is present in the cooking water after boiling.22Cumulative word count 3360EvaluationThe tube was shaken gently and consistently during each experiment after each drop of vitamin C solution to allow rapid diffusion of vitamin C throughout the DCPIP solution. Shaking the tube too cleverly may cause oxygen from air to dissolve and oxidise the reduced DCPIP solution, restoring the blue colour. Then, an increased volume of vegetable juice may be needed. All vegetable juices, as well as those boiled, should be titrated with the DCPIP solution once they have been extracted because vitamin C is easily destroyed by the atmospheric oxygen via oxidation. The DCPIP soluti on must be freshly prepared on the day of experiment. The DCPIP solution was filtered to avoid any impurities suspending at the bottom of test tube. Similarly, the vegetable juice was filtered to remove the vegetable pulp which may clog the burette tap.The non-edible parts and damaged leaf or stem of the vegetable samples were removed. Vegetables were cut into small cubes of about the same size so that the surface area exposed to the cooking water is constant. They were added into the pot only after the water starts boiling to keep the boiling temperature and season constant. A stainless steel pot was used as ordinary pots may have transition metals which may oxidise the ascorbic acid.Before starting the experiment, a rough titration was run to determine the exact colour change at the end point. For cauliflower, the colour may change from blue to pale yellow, which is the colour of the cauliflower juice. AppendixTo minimise inaccuracy, the procedure was repeated to get an average t itre. Eight types of vegetables were sampled to obtain enough replicates to support the hypothesis. A burette and pipette were used because of their high accuracy. burette readings are accurate to 0.05cm3. Since two readings are taken, there is a combined error of 0.1cm3. If the titre is 20.00cm3, the possible error due to apparatus is 0.5%.Cumulative word count 3682Limitations in this experiment include the ripeness, place of origin, storage and handling conditions of the vegetables.23The season of year and time of day from which the vegetables were picked were uncontrollable. They were bought from a hypermarket and were chosen based on their appearance such as colour and degree of damage.Modifications include repeating the experiment using other types of vegetables such as potatoes and carrots. Boiling may have different effects on different varieties of vegetables as their nutritional contents vary. Using only eight types of vegetables may give a wrong federal agency on the eff ect of boiling on the vitamin C content of all vegetables.The experiment can also be modified to investigate the effect of other cooking methods like deep-frying, steaming and microwave cooking on the vitamin C content of vegetables thus determining the best cooking method which results in token(prenominal) vitamin C loss.To ensure complete extraction of ascorbic acid, the vegetables can be blended with 5% metaphosphoric acid. This acid inactivates the enzyme ascorbic acid oxidase (an enzyme present in many plant tissue) which catalyses the oxidation of ascorbic acid when the cell components of a vegetable is mixed during blending.2425ConclusionBoiling significantly reduces the vitamin C content of vegetables (by 56.22%). The vitamin C content of raw vegetable is significantly higher than that of boiled vegetable.Cumulative word count 3947Source EvaluationSource 4 is a published book with ten contributors. Hence, the study provided is reliable and factual unless it has become out- dated since it was published in 1993.Source 5 (The Star) is Malaysias most widely-read English-language daily. One of its pullouts, Fit for Life, provides up-to-date articles on diet and nutrition. Therefore, the information can be trusted.ScienceDirect (Source 10) offers more than 2,500 peer-reviewed journals and more than nine million full-text articles. EBSCO (Source 11) provides online information databases and has a renewal rate of 99.6%. Thus, these online-journal sources are trustable.Source 12 is a website produced by the subject field Library of Medicine, a part of the National Institutes of Health. It shares extensive information on over 800 diseases and health conditions, and is reviewed at least every 6 months. Thus, it should be reliable.Cumulative word count 4087AppendixFigure 2 The colour change at end point for cauliflowerCumulative word count 4098