Sodium hydrogen carbonate and Vitamine C Zeevenhooven, L., Cuvelier, F. & Bosman, M. Gymnasium Felisenum Velsen-Zuid, Vrije Universiteit Amsterdam, The Netherlands Summary Vegetables contain Vitamin C. Vitamin C is important for people’s health. Vitamin C is stored in plant cells which are verry stiff, when heated, the cells will become permeable and weak so the vitamin C can leak out of the grociourie. Sodiumhydrogencarbonate affects the amount of vitamin C that has leached out of the plant cell. The hypotheses is that this process is dependent on the concentration sodium hydrogen carbonate. To test this hypothesis 5 portions of brocoli were heated and than boiled for 5 minutes in different concentrations sodiumhydrogencarbonate. The regained solutions we titrated with DCPIP, with a little math we could calculate how much vitamin C leached out. It seemed that the higher the concentration sodiumhydrogencarbonate was the more vitamin C leached out. Introduction Down in the dutch golden century, when ring system with an Mg2+ ion in its centre. people got sick at a ship after a long time When cooking with normal water there at sea, it was because of a lack of vitamin occurs an substitution of the Mg2+ by two C. Vitamine C is in first place important H+ ions. This gives a compound called for a good body resistance. Besides that it phenophytin, which is olive green/brown takes care of healthy bones, teeth and a and causes for the colour of overcooked good blood circulation. vegetables. In acidic conditions the substitution of Mg2+ by two H+ ions goes by smoothly. Sodium Hydrogen keeps the conditions alkaline and that will minimize the replacement of the Mg2+ ion and result in less conversion of chlorophyll to phenophytin, along with a more enticing Figure 1: molecular structure of vitamin C appearance to the vegetables. Sodium hydrogencarbonate, NaHCO3, is a Furthermore vitamin C is an antioxidant melecule of a strong base (sodium and it protects the body in coorporation hydroxide) and a weak acid (carbonic with vitamin E against the free radicals. acid). Free radicals play a part in the processes that make you older. Vitamin C also stimulates the adoption of irons. Vitamin C is sensitive for temperature and sodiumhydrogencarbonate. When heated very long the ammount of vitamin C will Figure 2: molecular structure of carbonic acid be decreased. When heated at a constant temperature with a different concentration The ammount of leaked out vitamine C can of sodium hydrogen carbonate more be calculated after the residu is being vitamine C will be lost. The colour of titrated with DCPIP. This is because the green vegetables is largely due to reaction that occurs is a redox reaction. chlorophyll. Chlorophyll has a porphyrin DCPIP is a strong oxidator. When it reacts as an oxidator the following reaction takes Experimental procedure and approach place. Broccoli was used to make five portions of 20 g with approximately the same grade of partition. This portions were cooked in solutions of NaHCO3 with different concentrations and in a stock solution with only distilled and deionised water. 0,1; 0,2; DCPIP 0,3; 0,4 ; mol/L solution was made by Oxidised form Reduced form weighing out the right amount by Figure 3: reaction of DCPIP as an oxidator considering that the solution shall be diluted by 200 ml distilled water. Five Pectin is a structural polysaccharide, which conical flasks were filled with the different is present in primary cell walls of plants. solution plus the broccoli. Each conical Pectin causes that the cell walls of a plant flask was cooked for 5 minutes. The five become softer during the ripening process. ‘cooking’ waters were then filtered into The same process takes places during beakers. Of each water there was taken cooking, pectins become soluble and are three times 10 ml by using a pipette and extracted into the cooking water making hydrochloric acid was added to the fifteen the vegetable go mushy. So the wall solutions untill the pH was beneath four. structure of the cells changes and this gives Otherwise the titrations with DCPIP don’t the opportunity to salts and vitamin C to work. We use DCPIP because it reacts escape. The pectin molecule contains – with vitmine C. It functions as an indicator COOH groups that react with from wich we can calculate later on how sodiumhydrogencarbonate. much vitamin C has leached out. By using NaHCO3(aq) + R-COOH(s) a burette with DCPIP for the titrations NaCO3(aq)+ H2O(l) + R-CO-(aq) Equation 1: pectin reacts with three results came out for the different sodiumhydrogencarbonate concentrations NaHCO3. The averages were used to calculate the ammount of Were doing this research because we find mole of vitamin C. This results were it interesting to know more about the food plotted versus the concentration of the we eat and how healthy the food is. NaHCO3 and compared with the ammount The research question is: What amount of of mole of vitamin C in the stock solution. vitamin C is leached out of the plant cells when heated at the same temperature in Results different concentrations of sodium For all titrations we took three times 10mL hydrogen carbonate? Thus which from each of the different concentrations. concentration of sodiumhydrogencarbonate The titrations were with DCPIP and for is most healthy to cook in? each concentration we worked out an Our hypothesis is that the leaching out of avarage of the added ml of DCPIP. Table 1 the vitamin C depends on the concentration shows the avarage of 0M after three sodiumhydrogencarbonate and the higher different titrations. the concentration the more vitamin C will 0M solution DCPIP solution be leached out. Because vitamine C reacts 10,0mL added (mL) with sodiumhydrogencarbonate and if we 10,00 2,38 add more sodiumhydrogencarbonate 10,00 2,30 vitamin C has a bigger possibility to react. 10,00 2,34 Avarage 10,00ml 2,34 Table 1 : added DCPIP solution (mL) In all the 4 heated beakers the solutions turned from a clear solution to a trebly brown solution. The higher the concentration sodium hydrogen carbonate, Concentration Average of added the browner the solutions became. After sodiumhydrogen- DCPIP(mL) the titrations with DCPIP the solutions carbonate (M) turned pink/ red. Table 2 shows the 0 2,34 obtained averaged ammounts of mL 0,10 1,33 DCPIP added to the recovered solutions 0,20 1,73 (0M-0,4) 0,30 1,93 0,40 2,52 Table 2: avaraged mL of the added DCPIP for each of the concentrations Data analysis Because of the fact that we used 176,13 u. The results of these calculations 9,14·10-4M DCPIP we could calculate are shown in table 4. how much mol DCPIP we added. Because DCPIP and vitamin C react in mol relation Moles vitamin C Leaked out 1:1 we also know how much vitamin C ammount of came free during the cooking proces. So to vitamin C (gr) calculate this we take 9,14·10-4M wich we 0,00214·10-3 3,769·10-4 multiply with the obtained mL of DCPIP. 0,00122·10-3 2,149·10-4 The results of the calculation are shown in 0,00158·10-3 2,783·10-4 table 3 and. 0,00176·10-3 3,100·10-4 0,00230·10-3 4,051·10-4 Concentration Moles DCPIP Tabel 4: calculated worths of vitamin C that is sodiumhydrogen- added to the 10 leaked out of brocoli in grams carbonate (M) mL solutions 0 0,00214·10-3 Discussion 0,10 0,00122·10-3 The results in tabel 4 show that our 0,20 0,00158·10-3 hypothesis was right, the higher the 0,30 0,00176·10-3 concentration sodium hydrogen carbonate the more grams vitamin C will leak out of 0,40 0,00230·10-3 Table 3: obtained moles DCPIP, and so the the cell. So the healthyest concentration is obtained moles vitamin C the lowest concentration because more vitamin C wil stay in the brocoli that you Now that we know the ammount of moles are going to eat, but not 0M because that of vitamin C came free in the solutions we has more vitamine C leached out. This is can calculate how much grams of vitamin because demiwater also weakens the C came free. Therefore you must multiply plantcells so vitamine C could easily the ammount of moles of vitamin C with escape. the molleculair weight of vitamin C wich is Our coorporation was very good during the investigation we didn’t had any problems at all. We had a slight problem when we used the wrong concentration of acid. For the rest everything went as planned and we found it fun to do.