Identity of not known carbohydrates composition

Category: Food and drink,
Published: 11.02.2020 | Words: 1132 | Views: 476
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A series of biochemical tests was carried out to spot unknown carbohydrates. There were six carbohydrates that needed to be identified; they have been arbitrarily labelled A-F. The sugars are sugar, fructose, maltose, lactose, sucrose and starch. There was six tests that have been carried out to help identify them, these were: Iodine Test, Solubility in Drinking water, Benedict’s test out, Acid Hydrolysis, Barfoed ensure that you Diastix test out.

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The goal of the experiment which was accomplished was to recognize the unknown carbohydrates by simply subjecting these to a series of biochemical tests.

The tests had been as follows: Iodine, Solubility, Benedict’s, Acid Hydrolysis, Diastix and Barfoed check.


There is 1g of every solid carbohydrate contained in bottles labelled A-F, 10ml of deionised water was included with each container using a computing syringe. The bottles were shaked very well to ensure that the carbohydrates were complete blended. The solubility of each sugars was recorded as well as the solutions had been retains for further testing.

If the carbohydrates dissolved totally in drinking water to give a clear view, this kind of meant these people were either a monosaccharide or a disaccharide, if the answer was gloomy then it was a polysaccharide. The next test that was completed was the Iodine Test. 12-15 drops of solution and 5 drops of iodine were added to a test tube and observed for any colour modify. This was repeated for each carbs. If the option turned blue-black, the carbohydrate is starch.

Carbohydrate Electronic turned blue-black while the others had simply no colour modify therefore it was concluded that Carbs E was identified as starch. As Carbs E was identified as starch, there were no further tests essential on this solution. The third evaluation that was completed was the Benedict’s test. In this test out, 40 drops of each option was included in the test pipe and 12 drops of benedict’s option was then added, test was put into a boiling water bath for 5 minutes. After 5 minutes, quality tubes had been removed and were analyzed to see if the solution offered the ‘brick red’ medications. 4/5 of the solutions offered a ‘brick red’ medications. This supposed the 4 that offered this effect was a lowering sugar we. e. sugar, fructose, maltose or lactose. The one that didn’t must be sucrose.

Further screening on carbs D was carried out to confirm it definitely was sucrose. Chemical p Hydrolysis evaluation was performed on this carbs D. 40 drops of any solution with drops of 0. 1M of hydrochloric acid was added to a test pipe and placed back in the hot water bath to get a further 3-4 minutes. After 3-4 moments, it was taken off and a few drops of Benedict’s answer was added and it had been put back inside the water bathroom for five minutes. After five minutes, it was clear to see that a ‘brick red’ medicine had produced. This concurs with it was sucrose as it is the only non-reducing disaccharide in this experiment. No further tests was accomplished on carbohydrate E. Barfoed test was carried out on the remaining some carbohydrates. 45 drops of each and every solution was added to a test conduit with 5 drops of Barfoed reagent. All four test out tubes were placed in a boiling water shower, changes were observed whilst in the drinking water bath, 2-3minutes for instant changes, then 15 minutes intended for slower alterations.

Carbohydrate A and C both provided a rapid quick change which meant the sugar can be described as reducing monosaccharide, either glucose or fructose. Carbohydrate Farreneheit changed to a brick reddish after a quarter-hour which meant the carbohydrate was recognized to be maltose. Carbohydrate W had not any precipitate kind, which meant it was lactose. The past test at all would discover what carbohydrate was sugar from alternatives A and C. Quality of Diastix used a strip which has been dipped in to carbohydrate A and C. If the coloring on the remove turned green-brown within 30 seconds, the sugars is glucose. Carbohydrate C gave this kind of result which meant it was sugar. Therefore carbohydrate C was glucose and carbohydrate A was fructose.


Carbohydrate| Solubility| Iodine| Barfoed Reagent| Diastix| Benedict’s Reagent| Chemical p Hydrolysis| A-Fructose| Soluble| X| Quick Rapid| X| Brick Red| Not Tested| B-Lactose| Soluble| X| No medications formed| X| Brick Red| Not Tested| C-Glucose| Soluble| X| Speedy Rapid| | Brick Red| Not Tested| D-Sucrose| Soluble| X| Certainly not Tested| X| No color change| Not really Tested| E-Starch| Insoluble| | Not Tested| X| Not really Tested| Brick Red| F-Maltose| Soluble| X| Change following 20 minutes| X| Brick Red| Certainly not Tested|


The effects that were recorded from the tests carried out closely matched the expected effects. The times which the precipitate will need to formed within just were often longer than expected, this may be because there was an error with counting the drops of solution in the test conduit so it had taken longer to react while using reacting agent.

The water bathroom took for a longer time than anticipated to get to a specific temperature and often couldn’t reach the right temp required. The results at the end were the same but only took longer to achieve all of them. During the Benedict’s test and chemical p hydrolysis check, the solution by no means gave an effective ‘brick red’ precipitate although more of a brown colour; this might be because the concentration of acid solution hydrolysis and Benedict’s remedy was too low to give an effective ‘brick red’ precipitate.


Throughout this kind of experiment, I use achieved the results which were expected. There are six carbohydrates to be determined with a number of tests to be done on them. We were holding correctly and accurately discovered. To keep the experiment valid, I made sure I scored the solutions exact and kept the temperatures from the water bath.

Key Words

5. Carbohydrates

* Benedict’s

5. Barfoed Test out

5. Solubility Test out

2. Brick Reddish Precipitate

* Polysaccharide/Monosaccharide

5. Acid hydrolysis

2. Iodine Test

5. Diastix

* Research


To summarize, the purpose of the experiment which has been carried out was to identify the unknown carbs by subjecting them to a number of biochemical assessments. This was achieved and the sugars were referred to as A-Fructose, B-Lactose, C-Glucose, D-Sucrose, E- Starch and F-Maltose. This investigation has shown that carbohydrates could be identified by simply simple biochemical tests.

Read more: Iodine Test for Polysaccharides

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