Identifying Macronutrients in food
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Bio-Med Science Academy**We aren't endorsed by this school
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SENIOR YEAR 675,678
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Biology
Date
Jan 14, 2025
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6
Uploaded by ConstableSnowLlama38
Identifying Macronutrients in foodAnalise LegereMs. AtthillSBI4UV - 01November 5, 2024Introduction:The primary goal of this experiment is to identify the macronutrient composition of four unknown food samples by testing for the presence of carbohydrates, proteins, and lipids. Carbohydrates, proteins, and lipids are macronutrients essential for energy, growth, and overall bodily function.●Carbohydrates: Organic compounds that provide energy to the body. They can be classified into monosaccharides (simple sugars) and polysaccharides (complex carbohydrates like starch).●Proteins: Biomolecules composed of amino acids, vital for tissue repair, enzyme production, and other biological functions.●Lipids: Fatty acids and glycerol compounds that serve as a concentrated energy source and are essential for cell membrane structure and insulation.To identify these macronutrients, the following biochemical tests are used:1.Benedict's test for monosaccharides (reducing sugars).2.Iodine test for polysaccharides (starch).3.Biuret test for proteins.4.Sudan III test for lipids.The experiment aims to determine the composition of unknown food samples and identify each sample based on the results of these tests.Hypothesis:
1.Sample 1 will test positive for carbohydrates, specifically polysaccharides like starch.2.Sample 2 will test positive for proteins.3.Sample 3 will test positive for lipids.4.Sample 4 will contain a combination of macronutrients, either carbohydrates and proteins or carbohydrates and lipids.Materials:●Unknown Food Samples: Sample 1, Sample 2, Sample 3, Sample 4●Reagents:○Benedict’s solution (for reducing sugars)○Iodine solution (for starch)○Biuret reagent (for proteins)○Sudan red (for lipids)●Test Tubes●Pipettes●Heat source (water bath)●Stirring rods●Distilled water●ThermometersProcedure:1.Preparation of Unknown Samples:○Place a small amount of each unknown food sample into separate clean test tubes.2.Carbohydrate Tests:○For monosaccharides (reducing sugars):■Add 5 mL of Benedict’s solution to each test tube.■Heat the test tubes in a water bath at 90°C for 5 minutes.■Observe and record any color change in the solution.○For polysaccharides (starch):
■Add 5 drops of iodine solution to each test tube.■Observe and record any color change.3.Protein Test:○Add 5 mL of Biuret reagent to each sample.○Observe and record any color change.4.Lipid Test:○Add 5 drops of Sudan III stain to each sample.○Shake gently and observe for the formation of a red-stained oil layer at the top.5.Record Results:○Record any color changes or observations for each sample.ResultsSampleBenedict's Test (Carbohydrates)Iodine Test (Starch)Biuret Test (Proteins)Sudan red Test (Lipids)Macronutrient(s) DetectedSample 1Green (Reducing Sugars)Yellow (No Starch)Blue (No Proteins)Clear (No Lipids)Carbohydrates (Monosaccharides)Sample 2Blue (No Sugars)Yellow (No Starch)Purple (Proteins Present)Clear (No Lipids)ProteinsSample 3Blue (No Sugars)Yellow (No Starch)Blue (No Proteins)Red (Lipids Present)LipidsSample 4Orange Blue-Black Blue (No Clear (No Carbohydrates
(Reducing Sugars)(Starch)Proteins)Lipids)(Monosaccharides, Polysaccharides)Interpretation and Analysis:The results from the macronutrient tests provided clear insights into the composition of each unknown food sample:●Sample 1: The green color change in the Benedict’s test indicated the presence of reducing sugars (monosaccharides). No starch, proteins, or lipids were detected, suggesting that Sample 1 is a carbohydrate-rich food, likely a fruit.●Sample 2: The purple color in the Biuret test confirmed the presence of proteins, while no reducing sugars, starch, or lipids were detected. Therefore, Sample 2 is identified as a protein-rich food, such as meat or legumes.●Sample 3: The red-stained layer from the Sudan III test confirmed the presence of lipids, while no carbohydrates or proteins were detected. This suggests that Sample 3 is a lipid-rich food, such as oils or dairy products.●Sample 4: The combination of positive results in the Benedict’s and Iodine tests indicated the presence of both reducing sugars (monosaccharides) and starch (polysaccharides), suggesting that Sample 4 is a carbohydrate-rich food, likely a starch-based food like potatoes or pasta.These results confirm the accuracy of the hypothesis and provide a clear identification of the food samples based on their macronutrient content.Evaluation:The results of the experiment were reliable, as they were consistent with the expected outcomes for each test. The control groups (glucose, cornstarch, pureed steak, and
plain yogurt) provided positive results for their respective macronutrients, validating the experimental procedure.Some potential sources of error, such as inconsistent sample sizes or improper reagent handling, could have influenced the results, but overall, the experiment was successful. Future improvements, such as ensuring consistent sample sizes and performing tests in replicates, could further increase the reliability and accuracy of the findings.ConclusionIn this experiment, the macronutrient composition of four unknown food samples was successfully identified using biochemical tests for carbohydrates, proteins, and lipids. The results supported the initial hypothesis and provided clear insights into the nutritional content of each sample.Sample 1 contained reducing sugars (monosaccharides), indicating it was primarily carbohydrate-based, likely a fruit. Sample 2 tested positive for proteins, suggesting it was a protein-rich food such as meat or legumes. Sample 3 revealed the presence of lipids, confirming it as a fat-rich food, such as oils or dairy products. Finally, Sample 4 exhibited both reducing sugars and starch, identifying it as a carbohydrate-rich food, likely a starchy item like potatoes or pasta. Overall the experiment's results were consistent with the expected outcomes and demonstrated the effectiveness of the biochemical tests in identifying macronutrients.
Work citedIdentifying Nutrients Gizmo : ExploreLearning. (n.d.). ExploreLearning : Get Hands-on, Minds-on in Math and Science. https://gz.explorelearning.com/index.cfm?method=cResource.dspView&ResourceID=452&ClassID=4834092