Biology Vitamin C

4. It would be difficult to measure the concentration of acid in red wine or coca-cola because the colour of the drink is too dark for us to see when the phenolphthalein indicator changes colour. You could overcome this difficulty by using a pH meter.

And finally into test tube 3, I pipetted 1.0 ml turnip extract and 4.0 ml of water. The contents of test tube 1 was poured into a spectrometer tube and labeled it “B” for blank. “B” tube was now inserted it into the spectrometer. An adjustment to the control knob was made to zero the absorbance reading on the spectrometer since one cannot continue the experiment if the spectrometer is not zeroed. A combination of two people and a stop watch was now needed to not only record the time of the reaction, but to mix the reagents in a precise and accurate manner. As my partner recorded the time, I quickly poured tube 3 into tube 2. I then poured tube 2 into the experiment spectrometer tube labeled “E” and inserted it into the spectrometer. A partner then recorded the absorbance reading for every 20 seconds for a total of 120 seconds. After the experiment, a brown color in the tube should be observed to indicate the reaction was carried out. Using sterile techniques, any excess liquid left was disposed

8 test tubes were then labelled A-H, 1ml of DCPIP was added to each of the test tubes. 2ml of NaHCO3 was added tubes A through G.

Lycopene and β-carotene are separated using thin layer chromatography (TLC). A mixture of tomato paste containing dissolved lycopene and β-carotene is first spotted on a TLC plate. The technique uses a stationary phase layer, on which the substances stick, and a mobile phase, which migrates upwards the plate and carries the components of the mixture with itself (Chemguide). Depending on their respective polarity, lycopene and β-carotene stick more or less to the stationary phase and so they migrate up the TLC plate at different rates (Chemguide). Thus, as the chromatography is completed, the two components will appear as distinct dots at different heights on the plate. Lycopene has a bright orange color, whereas β-carotene is light yellow.

Introduction: The goal or purpose of this experiment was to determine the concentration of Allura Red in red commercially available beverage- Gatorade. Colorimeter are used to shine a LED light through the solution and hit a photocell: it will detect an absorbance or a percent transmittance value. These “value” can be charted and examined as a calibration curve. Calibration curve is a method for determining a substance concentration in an unknown sample

~ From the example above, the dependant variable is banana quality and the independent variable is time

In this experiment redox-based titrimetric analysis was used to determine the amount of ascorbic acid (Vitamin C) contained in a serving of lemonade. This was done to confirm the 100 percent recommended daily allowance claimed on the package for a serving of Country Time Lemonade. The titration method used was adding a thyodene indicator to the analyte (lemonade solution) there is a visible colour change when the endpoint of the reaction between the titrant (KIO3) and the analyte occurs. The following reactions show how this titration method is viable. (Draw in reactions) KIO3 first reduced with iodide (I-) to generate iodine (I2 ) which then oxidized the ascorbic acid within the lemonade. Once all the ascorbic acid had reacted any iodine

6. Red cabbage juice is a natural, universal indicator. When a solution of red cabbage is red to pink, it indicates that a

Polyphenol oxidase catalyzes the oxidation of phenolic compounds into dark pigments (Sukhonthara et al., 2016) Inhibitors that could stop the polyphenol oxidase from catalyzing could stop the browning from occurring. Catechol oxidase is an enzyme that is found in most fruits and vegetables. It is known to enable the browning of cut fruits or vegetables by catalyzing a reaction between catechol and oxygen. The result of this reaction happening would be polyphenol, the browning that occurs when fruits or vegetables are exposed to oxygen. In this experiment, we are measuring different compounds that inhibit catechol oxidase from catalyzing benzoquinones.

The independent variable is sugar concentration. This will be changed by using solutions with different amounts of sugar (2%, 6%, 10%).

Table 4.12 and Table 4.13 shows the readings for the tests conducted at pH7 for the cationic dye and anionic dye solution. From the Figure 4.9 and Figure 4.10, it can be seen that the maximum color removal obtained is 85.67%, 83.30% and 78.93% for cationic dye and 71.83%, 64.08% and 62.91% for initial dye concentration of 25, 50 and 75mg/L respectively at WTR dose of 120mg/L. The trends of decreasing color removal continued with the increase in pH as the least readings were obtained at pH7.

Vitamin C - May help prevent cell damage and reduce risk for certain cancers,heart disease and other diseases.

In the preliminary test I used 3cm3 of DCPIP solution. A large amount of juice was needed to change the colour of the DCPIP to colourless. I changed the amount of DCPIP solution from 3cm3 to 1cm3. This is because less juice will be needed to change 1cm3 of DCPIP from blue to colourless. I used test tubes to hold the DCPIP and the 1% ascorbic acid but it was difficult to mix the two solutions together so I decided to use a boiling tube instead. I tested the 1% ascorbic acid in the preliminary test and I found that I need less than 3cm3 of the solution.

Vitamin C is an organic compound that is also known as ascorbic acid. The molecular formula for Vitamin C is C6O8H6. This structure contains a 5-membered ring. Vitamin C contains 4 alcohol functional groups, an alkene, and an ester. Within the ring it contains one double bond, the carbon=carbon bond in the ring structure, this is an alkene functional group. The Vitamin C structure also contains an ester which helps form the five-membered ring.

Vitamin C, or ascorbic acid, is a well-known supplement that is essential to the human body. Vitamin C helps grow and repair body tissue, make collagen, heal wounds, and strengthen bones and teeth. Unfortunately, the body does not produce this vitamin itself, therefore it must be obtained from another source. Vitamin C is present in significant amounts in both fruits and vegetables. These foods are commonly pasteurized – a process that applies heat to destroy pathogens that cause spoilage in food. Pasteurization is great for preserving foods, but its effects on the food’s contents are important to consider. This process could affect the levels of ascorbic acid in the foods being consumed for their vitamin C content. Specifically, orange juice, one of the most popular sources of vitamin C, is going to be used to examine the effects of pasteurization on ascorbic acid levels in this experiment.