Introduction
1.1 Background
1.2 Problem Statement
Globally, Dacryodes Rostrata, an underutilized fruit found in wild abundance in Malaysia lacks scientific information and knowledge. The expanse of research thus far has only investigated the antioxidant activity of this fruit using aqueous ethanol (Prasad et al., 2011). It has been suggested by Alothman and friends (2009) that varying solvent and conditions have a prominent effect on the accuracy of quantification of antioxidant content. However, till date the influence of other solvents on the antioxidant capacities of the peel, pulp and seeds of Dacryodes Rostrata have yet been identified.
1.3 Hypothesis and Proposed Solution
Many researchers have proposed that the recovery of polyphenols from plant materials will be influenced by the solubility of the phenolic compounds in the solvent used for the extraction process (Alothman et al., 2009). It has also been suggested that polarity of the solvent is fundamental in optimising phenolic solubility (Naczk and Shahidi, 2006). To investigate these claims, solvents from a range of polarities have been chosen and arranged from the least polar to the most polar as follows: hexane, ethyl acetate, butanol and water. Reseacher Sulaiman et al., 2011 has made a comparison between four solvent extractions on thirty seven raw vegetables and discovered that acetone extracts of 22 species gave the highest total flavonoid content whereas ethanol extract of 20 species gave the lowest reading and has concluded that 70% acetone is considered to be the most efficient solvent for extraction of flavonoids from the fresh vegetables. However Do et al., 2013 proposes that the extraction yield increases with increasing polarity of the solvent used in extr...
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...mixture was allowed to stand for 15 min and the absorbance was measured at 510 and 700 nm (UV–vis spectrophotometer against a blank of distilled water.
Following the same procedure, extract was then added to 0.025 M sodium acetate buffer at pH 4.5, and the absorbance was again measured at 510 nm and 700 nm after 15 min.
The total anthocyanin content was calculated using the following equation:
Total anthocyanin content (mg/l) = (A ×MW × DF ×1000)/(ε × C)
where A is absorbance of the extract calculated as:
A = (A515 - A700)pH 1:0 - (A515 - A700)pH 4:5
MW is the molecular weight for cyanidin-3-glucoside = 449.2; DF isthe dilution factor of the samples, e is the molar absorptivity of cyanidin-3-glucoside = 26,900; and C is the concentration of the buffer in mg/ml. Results were expressed as mg of cyanidin-3-glucoside equivalents (c-3-gE) for 100 g of sample.
The objective of this experiment was to perform extraction. This is a separation and purification technique, based on different solubility of compounds in immiscible solvent mixtures. Extraction is conducted by shaking the solution with the solvent, until two layers are formed. One layer can then be separated from the other. If the separation does not happen in one try, multiple attempts may be needed.
Firstly, an amount of 40.90 g of NaCl was weighed using electronic balance (Adventurer™, Ohaus) and later was placed in a 500 ml beaker. Then, 6.05 g of Tris base, followed by 10.00 g of CTAB and 3.70 g of EDTA were added into the beaker. After that, 400 ml of sterilized distilled water, sdH2O was poured into the beaker to dissolve the substances. Then, the solution was stirred using the magnetic stirrer until the solution become crystal clear for about 3 hours on a hotplate stirrer (Lab Tech® LMS-1003). After the solution become clear, it was cool down to room temperature. Later, the solution was poured into 500 ml sterilized bottle. The bottle then was fully wrapped with aluminium foil to avoid from light. Next, 1 mL of 2-mercaptoethanol-β-mercapto was added into fully covered bottle. Lastly, the volume of the solution in the bottle was added with sdH2O until it reaches 500 ml. The bottle was labelled accordingly and was stored on chemical working bench.
To complete this lab several chemicals must be measured and transferred to test tubes. First 5.0 mL of 0.200 M Fe(NO3)3 must be diluted to a total volume of 50 mL in a flask. Next 0.0020 M SCN–. This solution is then added to 4 test tubes in 1 mm increments. Each test tube is then put in to
Abstract/Summary: “Proteins account for more than 50% of the dry weight of most cells, and they are instrumental in almost everything organisms do” (Campbell, 1999). The significance of proteins to the continuation of our biological systems is undeniable, and a study of how to quantify proteins seems an appropriate introduction to our studies of biology. In order to study proteins we must first know how to separate then quantify the amount using basic principles of experimental design such as a standard curve. In this experiment we wish to quantify the amount of previously extracted protein by measuring the absorbance of the unknown amount and determining its concentration by overlaying it against a standard curve of the absorbance of known concentrations of the protein. We used the dye agent Bradford Protein Assay to get an absorbance of 0.078, 0.143, 0.393, 0.473, and 0.527 at the protein’s respective concentrations of 0.28, 0.56, 0.84, 1.12, and 1.40 mg/mL. When a best-fit line was applied to the standard curve, and the absorbance of our unknown concentration (0.317 A) plotted, we estimated a concentration of around 0.84 mg/mL of protein. Our calculations indicated a quantity of 168 mg of protein, which was an approximately 8.96% yield of the projected 1875 mg that was expected. Errors that may have led to this small yield percentage may have stemmed from our previous lab and our initial attempts to extract the desired amount of protein.
Materials and Methods: An ion exchange chromatography column was obtained and set up for purification with the addition of 0.5 ml ion exchange matrix. 1 ml
Anthocyanins, flavanols, flavanones,secoiridoids, phenolic acids, stilbenes, coumarins, and isoflavones form a large class of polyphenols, which are phenolic compounds. This study, however, focuses on one category of these phenolic compounds: phenolic acids. These particular compounds have been classified into two groups, namely hydroxycinnamic acids and hydroxybenzoic acids. The most common hydroxybenzoic acids are protocatechuic acid and gallic acid, while hydroxycinnamic acids include ferulic acid, coumaric acid, caffeic acid, chlorogenic acid, and sinapic acid, (Nigdikar, Williams, Griffin, & Howard). Unlike hydroxycinnamic acids, hydroxybenzoic acids usually occur at very low levels in some black radish, red fruits, and onions, accounting for about 10 ppm on a fresh weight basis. Protocatechuic ac...
If a substance has color, then you can determine its concentration by light absorption which is when light is being taken up by an object or spectrum. The Beer-Lambert Law is commonly used to find the absorbance (A) of light in a solution by multiplying the molar absorption coefficient ( ε ) ( how well a chemical absorbs light at a given wavelength ), the concentration ( C ) and the path of the light through the sample solution ( l ). The equation for this relationship is “ A=εCl ”. The color of the solution is determined by the color of light the molecules do not absorb, so, say if you had a blue colored solution, then the color of light will be orange. This is because the highest molar absorption coefficient for blue dye falls around 620 nanometer which is the orange part of the visible electromagnetic spectrum.
...eadings. The absorbance readings for test tube 5, were always further away from the expected values than test tube 1. This is because the NaOH was not added to each tube at a time, but in sequential order with the test tube numbers. This allowed the reaction in test tube 5 to proceed longer than in test tube 1, allowing more product to be produced, giving a higher absorbance reading than expected. In fact, this trend was shown in all the test tubes. In increasing order of test tube numbers, every absorbance was more off than expected.
In this experiment, lipids from ground nutmeg are extracted using a combination of solvents and identify the lipids through chromatography. The purpose of using solvent combinations is to elute the lipids based on their polarity to binding of the silica gel. The chromatography is performed on a silica gel plate and the use of iodine to visualize the lipids. By calculating the Rf values for each compound and comparing them to the known lipids, we are able to distinguish the lipids within the grounded nutmeg.
The hypothesis stated that when the spinach extract was placed on the polar paper chromatography the pigment would separate into different pigments on the...
...eases, including temperature. It is determined from the data that the reaction is more likely to have a step wise mechanism than a concerted due to the small – ΔS and a relatively large value of ΔH from the tables. Due to some errors, it is best to perform another experiment for future protocols. In addition with the variance the 35°C where at one point the absorbance levels off and then increases. In comparison to the rate constant against temperatures, at 25°C it is higher than 35 and 45. More test is required to ensure proper determination of the rate constant at those temperatures.
...s the change in the temperature of both of these batches, 6°C for the pure, and 13°C for the crude. In this final sub-section of the Characterization of Aspirin, the values of absorbance were recorded. Initially, 0.0566 grams and 0.0590 grams of pure and crude Aspirin respectively were obtained and each individually placed into beakers (400 milliliter) and had 250.0 milliliters of distilled water added to them. From each beaker, a tiny amount of the just dissolved solutions was transferred to a cuvette, one cuvette for each type of aspirin. Each cuvette was placed into the ultraviolent spectroscopy mechanism which was connected to a computer and absorbance spectrum values were obtained at 298 nm (Figure 5) (0.1987 pure aspirin, and 0.9549 crude aspirin).
Furthermore, an additional method to use other hydrochloric acids that have different concentration levels such as 1 M and 2.5 M ones, can improve the outcome of the results. This increases the variation of the independent variable, which accordingly increases the precision of results.
EDTA Titrations [homepage on the internet]. No date. [cited 2014 Mar 24]. Available from: http://bionmr.unl.edu/courses/chem221/lectures/chapter-12.ppt.
Tannins, a natural compound produced by many plants, have become a common topic when discussing various beverages and fruits, yet the truth is that tannins are compounds that can be found in most all plants and have a much more involved significance than astringent taste. Tannins are a type of plant product that is classified as a polyphenol (Cornell University 2014). Polyphenols, also referred to as phenolic compounds, can have a high molecular weight due to the attachment of one or many hydroxyl groups to an aromatic ring structure (Balasundram 2006). Phenolic compounds can commonly be found connected to single and complex sugars within plants (Balasundram 2006). There is a vast diversity within the plant polyphenols as related to composition, yet polyphenols are categorized into 12 different classes based on structure (Balasundram 2006). Tannins along with