What Is With Grade...by::D20071029415

Is there any relationship between grade and protein concentration in egg?

Chicken eggs are the most commonly add protein to one's diet as well as other nutrients . They supply all essential amino acids for humans, and provide several vitamins and minerals. They are also a cheap single-food source of protein. Protein are the most abundant biological macromolecules occurring in all cells in our body. Proteins are compounds, which contain carbon, hydrogen, oxygen, nitrogen, and sometimes sulphur. Each protein molecules is made from a large number of molecules of amino acids, joined together by peptide bonds.
Proteins by themselves are usually colourless and therefore it is difficult to measure the presence of protein. An easy way to solve this problem is to stain the protein with biuret reagent and measure the amount of absorption of the Biuret reagent by a spectrophotometer. The spectrophotometer is an instrument that is used to measure the intensity of the colour of a solution. When Biuret reagent reacts with peptide bonds it produces a violet colour which will be detected by the spectrophotometer. The violet colour indicates a positive Biuret test for protein, the more protein presents the darker the colour of the solution.

So, how should we determine protein concentrations in eggs? There are a number of ways. In many lab experiments, for example, determining the amount of protein biomolecules in a given solution is essential. In addition, the experiment is perform to determine if absorbance levels correspond with protein concentrations in solutions. In addition, it is very important that the method by which the protein concentrations of various substances were determined apply universally. In other words, the method must work in every test in which it is used. The method chosen for this experiment was the Biuret Assay method, which requires that the solutions being tested be mixed with a Biuret reagent and run through a spectrophotometer.

In order to determine how much protein is represented by a particular absorbance reading it is necessary to construct a standard curve.This is done by performing the biuret reaction on a serial dilution using six tubes. The absorbance readings obtained from these samples are used to construct a graph of absorbance as a function of protein concentration. This graph is called the standard curve for the assay, and can be used to convert the absorbance readings for the experimental samples into a protein amount. One of the sample in the list with no protein added is blank that should be used to zero the spectrophotometer. Blanks are useful when there are other substances in the experimental tube besides the substance we are trying to measure. Since those other substances are not the chemical that we are trying to measure, they often interfere with the absorbance reading of the chemical of interest. The way to do that is to use a blank. A blank contains all the substances in the experimental tube except the substance that is being measured. Then, before reading our experimental tube, we place the blank tube in the spectrophotometer.

Record the data from the biuret reaction on the standard protein concentrations in a spreadsheet. Make an x-y line graph of the results. The protein concentration should be on the x axis, and the absorbance on the y axis. The line on the graph relates the protein concentration to the absorbance of the biuret reaction. We use this standard curve to convert the absorbance that we measured back to the amount of protein in the sample given. Using the data from six samples, a standard curve was graphed. The remaining four samples, A, B, C and X, the unknown solutions, were run through the spectrophotometer. The results are shown below:

Table above shows the average results of absorbance from four unknown solution protein concentration resulted from the equation we got at the standard curve graph above.

Graph above shows the standard curve of absorbance vs concentration of gelatin (protein).

Table above shows the average results of absorbance from six different protein concentration (gelatin).

Because the data of this experiment was used to create a standard curve graph for protein concentration of known solutions, it is possible to accurately identify protein concentrations in any number of unknown solutions. One implication of these results is that protein concentration and absorbance are linked, and correspond to each other, as was initially predicted. But, there are no differences between the grade and the concentration of protein. The grade only make difference in the quantity and shape of the egg and not the concentration of protein, which based to the experiment result we got above. There also is no difference in nutritive value between the different grades. Because production and marketing methods have become very efficient, eggs move so rapidly from laying house to market that you will find very little difference in quality between.

By Siti Maimun Ali Al Tamas
(D20071029415)

Egg For Life

When I want to buy eggs in a grocery, hypermarket or even “pasar malam”, the first think that I consider is a quality or the grade of the egg. Then, number two going to the price. Frankly speaking, until now, I still believe that egg with the grade A are among the healthiest egg in a market. Egg can be graded as AA, A , B and C. I really care about what I am eating, so for me, I make a conclusion deep inside my heart. The egg with the higher grade (and of cause with the higher price) has a higher protein level that will help me for growth. But, since last week, after done a lab experiment about protein, I realize that grade A are not “sehebat yang disangka”.

When I look into the result about the concentration of protein from our group experiment, clearly shown that the egg with the grade B has higher protein level compare to the other grade group. Our result shown that with a clearly evidence. Refer to the table; the grade B egg has higher concentration of protein which is 10.689 mg/L compare to the grade A egg which is only have 10.582 mg/L. The X egg which is I assume as a duck egg even have more concentration of protein which is 12.429 mg/L. Such a big number BUT I did not eat duck egg. Eeee.... (sambil meremang bulu roma)

So, I try to search information about the differences between the grades of the egg. Here what I got. In the grading process, eggs are examined for both interior and exterior quality and are sorted according to weight (size). Grade quality and size are not related to one another. In descending order of quality, grades are AA, A and B.

Grade AA
The insides of the egg cover a small area. The white is firm. There is a lot of thick white around the yolk and a small amount of thin white. The yolk is round and stands up tall.

Grade A
The insides of the egg cover a medium area. The white is pretty firm. There is a good amount of thick white and a medium amount of thin white. The yolk is round and stands up tall.

Grade B
The insides of the egg cover a very wide area. The white is weak and watery. There is no thick white and the large amount of thin white is spread out in a thin layer. The yolk is large and flat.

In a nutshell, the grade of an egg is not representing the real percentage of protein content that we can get from it for our healthy. So, start from now, I only buy egg with a sign GRADE B. cheaper and healthier.

p/s : Mengapa bayar lebih ? Jadilah pengguna bijak.

MUHAMMAD AIEZAD BIN ASNI. D20071029434.

What Is With Grade..By:: D20071029417(suhaiza))

salam....

here is my opinion...hehe...

We know that the egg have it own grade, whether it is egg grade A, grade B or grade C. This egg grade we can found in the market. But do you know how actually the process to graded the eggs? The person who grade the egg will checking both outside and inside of the egg. On the outside, the checker looks to see if the shell is clean and unbroken and has a normal shape and texture , without bumps, ridges, thin spots or rough areas. The shell color doesn't matter. On the inside, the checker looks to see if the white is firm, thick and clear. The checker also looks to see if the yolk is the right size and shape and has no blemishes. Through the shell, the checker can see the size of the air cell, too. The smaller the air cell, the higher the grade. Eggs are graded AA, A , B and C. AA is the highest just like an A+ is the highest school grade. The process of grading is called candling because in past, they were held up behind an egg so the checker could see inside the egg without breaking it. Today, eggs move on rollers over a strong light instead of a candle.

As we know egg consist of a lot nutrient inside it, one of the nutrients is protein. So it is important to us to know the concentration of protein inside every grade egg whether grade A, grade B, grade C and may be egg from “Ayam Kampong”. One of experiment that we can use to determine the concentration of protein is protein assay by using Biuret assay method. The concentration of protein is measured by the wavelength of 540nm, A540, by using spectrophotometer. Six solutions with known protein concentration were passed through the spectrophotometer and their absorption level discovered.

What will have to do to determine the concentration of protein is first, we mix 1mg/ml of 0.50ml of gelatin (protein) with 2.5ml of Biuret reagent into the cuvette. Then, we repeat the first step by replacing 1mg/ml of 0.50ml of gelatin by 2mg/ml, 3mg/ml, 4mg/ml, 5mg/ml and 6mg/ml of 0.50ml of gelatin into other prepared cuvettes. Then we put each cuvette with different protein concentration into the spectrophotometer and measure the absorbance after 10 minutes, then the results are recorded in the table below.

Table 1: The absorbance of light at 540nm of different gelatin concentration

Table 2 : The absorbance of light at 540nm of different types of egg

Key:

Sample A: Grade A egg

Sample B: Grade B egg

Sample C: Grade C egg

Sample X: “Ayam kampong”

Graph 1: The absorbance of light at 540nm versus the different gelatin concentration.

Actually the concentration of protein is not depend to the grade of egg.So, the conclusion is the grading of the egg has nothing to do with the nutritional value.

These are my experimentally opinion...

Thank you...=)

::Suhaiza Bt Rozani::

::D20071029417::

D20071029418 (ZARINA)

What Is It With Grade?

cuvettes with gelatin

Does the grade of an egg determine the protein content in it? To answer this question, we must care about the protein concentration in solutions (eggs). This is because, in my lab experiment objectives to determining the amount of protein biomolecules in a given solution is essential, to learn a method by which protein concentrations could be determined in sample of eggs and determine if absorbance levels correspond with protein concentrations in solution.

In this experiment, the spectrophotometer is an instrument that is used to measure the intensity of the color of a solution. When Biuret reagent reacts with peptide bonds it produces a violet color which will be detected by the spectrophotometer. The violet color indicates a positive Biuret test for protein, the more protein presents the darker the color. Hence, a appropriate blank is necessary to set the spectrophotometer reading at zero.

Various method can be used to determine the concentration pf protein in solution, for the example, Biuret assay, Lowry assay, and Bradford (Bio-Rad). The method chosen for this experiment was the Biuret Assay method. The concentration of protein is measured by the wavelength of 540nm, A540, by using spectrophotometer.First, we mix 1mg/ml of 0.50ml of gelatin (protein) with 2.5ml of Biuret reagent into the cuvette. Then, we repeat the first step by replacing 1mg/ml of 0.50ml of gelatin by 2mg/ml, 3mg/ml, 4mg/ml, 5mg/ml and 6mg/ml of 0.50ml of gelatin into other prepared cuvettes. Then we put each cuvette with different protein concentration into the spectrophotometer and the results are recorded in the table below.

Table 1: The absorbance of light at 540nm of different gelatin concentration

Table 2 : The absorbance of light at 540nm of different types of egg

Key:

Sample A : Grade A egg

Sample B : Grade B egg

Sample C : Grade C egg

Sample X : duck egg

Due to the equation y = 0.0747x – 0.0725

Calculation:

The comparison of protein concentration and prices among eggs.

From the experiment result, the concentration of protein in duck egg (sample X ) is highest between the others grade sample of eggs (A,B and C), which is has 12.429mg/L. The grade A’s egg has less 1.817mg/L concentration of protein than duct egg. In the market, I found that the cost for a duct egg is RM0.80. Wow..! it very expensive rather than other grade of eggs. The cost for a grade A’s is only RM0.34, grade B’s is RM0.32 and grade C’s is RM0.030. In average that mean, the cost for only a duct egg, we can get than two times of grade A’s, B’s or C’s egg.

Besides, the grade B’s has concentration of protein is 10.689mg/L. If compare the duct egg and the grade B’s egg, the duct egg has more 1.746mg/L concentration of protein than grade B’s egg. As we know, the cost for the grade B’ egg is RM0.32 and for the duct egg is RM0.080. So, I will prefer to buy grade B egg between both because it is cheaper and the protein content in both types of eggs just slightly different.

When I compare the protein content in grade B’s egg and grade C’s egg, I found that grade C egg only has a concentration of protein 0.825mg/L. While grade B’s egg has more 2.673mg/L of protein content compared to grade C’s egg. In market, a grade C egg is RM 0.30 while grade B’s egg is RM 0.32. Since grade B’s egg is has more protein content than grade C egg, so, between B and C I will choose to buy grade B egg.

In the other hand, when I compare the concentration of protein between grade A’s and grade B’s egg, the grade B’s egg has only higher 0.107mg/L than grade A’s egg. Since the cost different between grade A and B eggs is RM 0.02 but grade B egg has higher protein content. As a result, I will choose to buy grade B egg.

As a conclusion, the grade of an egg is not represent the real percentage of protein content that we can get from it for our healthy. As a wise consumer we should choose to buy grade B egg because it has more protein content 10.689mg/L, more valuable and has low of cost.

What Is With Grade..By:: D20071029420(mastura)

salam....

here is my answer..(more to opinion actually..but experimentally opinion...(",))

Grade, the word comes with a meaning of something that had been rating or placed in sequence based on their own category. But how about the grade of an egg? Does the grade of an egg determines the protein content in it? Majority option to buy egg from the grocery with two factors: cheap and fresh. Some people will consider about the quality of the egg; omega-3, free antibiotic, free cholesterol and others. But, do we know how to determine the protein content in the egg? Let’s check it out!!

Protein assays is one of the method to determine the protein concentration. In this lab session, the concentration of the protein is measured by a wavelength of 540nm by using s spectrophotometer. Firstly, we mix 1mg/ml of 0.50ml of gelatin (protein) with 2.50ml of Biuret reagent. Then, the first step will be repeated by replacing the 1mg/ml g of 0.50ml gelatin with 2mg/ml, 3mg/ml, 4mg/ml, 5mg/ml and 6mg/ml in other cuvettes. Then, we placed each of the cuvettes into the spectrophotometer and measured the absorbance value. The results are recorded as shown below.

Table 1: The absorbance of light at 540nm of different gelatin concentration.

Table 2: The absorbance of light at 540nm of different types of protein.

Key:

Sample A: Grade A egg

Sample B: Grade B egg

Sample c: Grade C egg

Sample X: Organic egg

Graph 1: The absorbance of light at 540nm versus the different gelatin concentration.

From the results above, we can say that there is nothing to do with the grade of egg related to the protein contain in it. If we look at the grade B egg, the protein content is higher than grade A egg. While the organic egg contains the most highest protein content compare to the other three grade eggs.

Actually, there are several ways to indicate the grade of each egg, not by indicating the protein content in it. The grading is done with a series of test where the eggs are examined for many qualities such as size and weight. The eggs are first washed to make sure they are spotless and sent to be candled. Candling is a way performed by hand to examine the content of the egg. This is done by passing them a light which allows the shell to be viewed internally. The conditions of the shell, white and yolk are examined. This is what will later divide the eggs into different grades.

The weight is done by the carton, not the individual egg, and computer controlled sensors weigh each egg over 60 times in less than one second. There is only a 3 ounce difference per one dozen eggs of a different size so the accuracy of the weight of each carton is important. Here are some characteristics of each grade of the egg:

Grade A: The egg is found in perfect condition. The shell is not cracked at all, is fully clean, and the yolk is round and centered in a firm white with a minimal air pocket. These eggs will be processed for shipping to retail stores for consumers to buy.

Grade B: This egg also has an un-cracked shell but may have a rough texture. The white will be watery/thin and the yolk somewhat flat. These eggs are saved for commercial uses such as selling to bakeries or for processing into other foods like making mayonnaise or noodles.

Grade C: Eggs with this grade likely have a cracked shell, loose yolk, and very thin white. This will only be sold to commercial processors as use as an additive for other products.

Technology has played a significant role in the production of eggs. So, the conclusion is the grading of the egg has nothing to do with the nutritional value. So, we don’t have to think about the grade when we want to eat the egg. Just eat it as long as you don’t take it over the limit..

TQ.

::Mastura Haji Ariffin::
::D20071029420::