Abstraction
In this experiment, reactions of different samples of saccharides were observed utilizing different trials. The merchandises were classified when the samples reacted by demoing positive colour alterations. The group used 7 saccharide samples and 2 unknown samples in different saccharide trials. Precisely 0.20 milliliter of each sample was sited in separate trial tubings with 0.20 milliliters different needed reagents for each trial. Unknown sample 1 turned out to be Fructose while unknown sample 2 turned out to be Ribose. In the last portion, hydrolysis of amylum was observed.
Introduction
One of the chief types of foods is the saccharides. Carbohydrates are the most critical foundation of energy for your organic structure. Our digestive system has a capacity to alter saccharides into glucose or most normally known as blood sugar. Our organic structure gets energy used by our cells, tissues and variety meats from this sugar. Carbohydrates besides shops extra sugar in our liver and musculuss.
Carbohydrates may be simple or complex depending on its chemical construction. Simple saccharides are besides known as simple sugars. They are normally established in refined sugar such as white sugar. Complex saccharides of starches includes grain merchandises like staff of life, crackers, pasta and rice.
MATERIALS AND METHODS
A. Designation of Unknown Carbohydrate Samples
Approximately 1.00 milliliter of the known saccharide samples and the two unknown samples were transferred on separate labelled trial tubing. About 1.00 milliliters of Molisch reagent so 1.00 milliliter of concentrated H2SO4 was added to each sample. The trial was observed for any alteration and was recorded. With the usage of new batch of samples each clip, the staying trials were conducted:
( a ) Iodine trial – 1.00 milliliter of iodine reagent was added to each sample.
( B ) Benedict ‘s trial – 1.00 milliliter of Benedict reagent was added to each sample so heated utilizing H2O bath.
( degree Celsius ) Barfoed ‘s trial – 1.00 milliliter of Barfoed ‘s reagent was added to each sample so heated utilizing H2O bath.
( vitamin D ) Seliwanoff ‘s trial – 1.00 milliliter of Seliwanoff reagent was added to each sample so heated utilizing H2O bath.
( vitamin E ) 2,4-DNP trial – 1.00 milliliter of 2,4-DNP was added to each sample so heated utilizing H2O bath.
The individuality of the unknown samples was determined by comparing it to the known saccharide samples.
B. Hydrolysis of Starch
Precisely 50.0 milliliter of 5 % starch solution was transferred in a 100-ml beaker. Precisely 5.00 milliliter of concentrated sulphuric acid or hydrochloric acid was added. The sample was covered with aluminium foil and was heated utilizing H2O bath. Two 1.00 ml volume of the sample were transferred in a trial tubing. Precisely 1.00 milliliter of iodine reagent was added to one tubing and 1.00 milliliter of Benedict ‘s reagent was added to the other. The reaction was observed. The sample was heated continuously. Two 1.00 ml volume of the sample was transferred between every 5 minute interval and tested with I and Benedict ‘s reagent as above until formation of blue-black composite in I Michigans and formation of brick ruddy coloring material in Benedict ‘s reagent ensues.
RESULTS AND DISCUSSION
The tabular array below shows the positive colour alteration for saccharides based on the experiment.
Trial
POSITIVE COLOR CHANGE
Molisch
Red to deep purple
Iodine
Blue black
Ruth fulton
Brick red
Barfoed
Brick red
Seliwanoff
Red
2.4-DNP
Cloudish orange
Table 1. Positive colour alteration of saccharides in different trials.
The tabular array below shows the reactions of saccharides based on the experiment.
Samples
Molisch
Iodine
Ruth benedicts
Barfoed
Seliwanoff
2,4-DNP
Glucose
+
–
++
+
–
–
Galactose
+
–
++
+
–
–
Ribose
+
–
+
–
–
–
Fructose
++
–
++
++
++
++
Lactose
+
–
+
–
–
–
Sucrose
++
–
–
–
+
+
Starch
+
+
–
–
–
–
Unknown 1
++
–
++
+
++
++
Unknown 2
++
–
+
–
–
–
Identity of Unknown 1
Fructose
Identity of Unknown 2
Ribose
Legend: ( ++ ) – Fast reaction ; ( + ) – Slow reaction ; ( – ) – No reaction
Table 2. Chemical reactions of saccharides in different trials.
In Molisch trial, the consequence turned out to be positive or slow reaction. It is because of the formation of the reaction with alpha-naphthol in the happening of sulphuric acid. In this trial, all type of saccharides will give a positive consequence.
Figure 1. Chemical reaction of Molisch trial.
Benedict ‘s solution is a deep-blue alkaline solution used in proving the being of the aldehyde functional group, -CHO. Benedict ; s reagent consists of bluish Cu ( II ) ions which are condensed to Cu ( I ) .These ions are precipitated as ruddy Cu ( I ) oxide which is non soluble in H2O. In Benedict ‘s trial, monosaccharoses and disaccharides except for sucrose give a positive consequence. It is when the consequence is a brick ruddy precipitate.
Figure 2. Chemical reaction of Benedict ‘s trial
In Barfoed ‘s trial, the Cu ion in solution oxidizes cut downing monosaccharoses. This is for the formation of a carboxylic acid and ruddy precipitate of Cu ( I ) oxide in 3 proceedingss.
Figure 3. Chemical reaction of Barfoed ‘s trial.
In Seliwanoff ‘s trial, the reagent dehydrates ketohexoses to organize 5-hydroxymethylfurfural which will further respond with resorcinol, that is present in the reagent, to bring forth a ruddy merchandise in 2 proceedingss.
Figure 4. Chemical reaction of Seliwanoff ‘s trial.
In Iodine trial, all polyoses such as animal starch and amylum give positive consequence. The sample turns to bluish black colour.
The tabular array below shows the hydrolysis of amylum.
TIME ( min )
Color with Benedict ‘s trial
Time ( min )
Color with Iodine Test
5
Blue
5
Blue black
10
Red brick
10
Brown
Table 3. Hydrolysis of Starch
