CHM101: Practical Lab Report on Extraction and Analysis of Food Lipids

This practical assignment details a chemistry experiment (CHM101) focused on the extraction and analysis of lipids (fats) from common food items, including chocolate chips, potato chips, sunflower seeds, and almonds. The experiment involves both qualitative and quantitative analysis. Initially, a qualitative test using brown paper is performed to detect the presence of fats. Subsequently, a quantitative analysis is conducted where the foods are crushed, and lipids are extracted using acetone. The extracted fats are then analyzed, and the percentage of lipid extraction is calculated. Observations are recorded regarding the color, texture, and viscosity of the extracted fats. The assignment includes a ranking of foods based on their fat content, comparison with dietary information, and an analysis of the types of fats present (saturated vs. unsaturated). The report also discusses potential sources of error in the experiment and concludes with a summary of the findings, emphasizing the differences in lipid content and composition among the tested foods, and comparing the results to the nutritional information of the food packages. References are also included.

ESSENTIALS OF CHEMISTRY (CHM101) 1
Essentials of Chemistry
Name of the Student
Name of the Affiliate Institution
Course Name
Course Number
Instructor’s Name
Date

ESSENTIALS OF CHEMISTRY (CHM101) 2
OVERVIEW
Activity Objective
 To extract and detect fats from chocolate, potato chips, sunflower and almonds.
Materials Required
 Packaged food to test (chocolate chip,
 potato chips,
 sunflower seeds,
 almonds
 Acetone:
 8 jars/glasses/non-plastic containers
 measuring vial (that can approximately measure 20 ml) or teaspoon (1 teaspoon = 5
ml)
 balance/scale
 microwave
 brown paper bag
 4 zip-lock bags
 hammer/rolling pin
 marker/label
 gloves (preferably natural latex/rubber or butyl)
EXPERIMENT PROCEDURE AND RESULTS
PART 1: QUALITATIVE DETECTION OF INVISIBLE FATS IN FOODS
1. Cut up the brown paper bag into squares about 10 cm wide.
2. Place a few grams (approx. ½ teaspoon) of each food on a separate piece of paper.
3. Microwave each food separately on High for 25-40 seconds.
4. Fold the paper over the microwaved food and press hard (some food needs more force to
crush, use rolling pin or hammer). Allow it to dry for 5 min.
5. Record your observations.
Results:
HOUSEHOLD FOOD OBSERVATIONS ON THE PAPER
Chocolate chip Grease spot is observed having spread beyond
the chocolate
Potato chips Large wet grease spot is observed on the
paper

ESSENTIALS OF CHEMISTRY (CHM101) 3
Sunflower seeds Grease spot is seen only where the seed
touches the paper
almonds Large grease spot on the paper
PART 2: QUANTITATIVE ANALYSIS OF INVISIBLE FATS IN FOODS
DAY 1
1. Weigh out each of the empty 4 jars/containers and record their weights in the table
provided.
2. Separately weigh about 10 g of each food, place it in separate zip-lock bags and
crush each food item. Be careful as seeds are sharp and may pierce the bag. It does
not need to be finely crushed into a powder.
3. Place each of the crushed foods into the pre-weighed jars and label the jars. Now
weigh all the full jars and record in the table provided.
4. Take empty new 4 jars/containers and label them with each of the four foods. They
will be used in the next step.
5. Now repeat extraction by adding another 10 mL of acetone, swirl and decant into the
same labelled jar/container previously used.
7. Leave both jars (with wet food and with decanted acetone solution) to evaporate
overnight. Make sure they are placed well away from anyone and from open flames,
in a well-ventilated area.
8. REPEAT STEPS 5-7 for the remaining 3 foods. You should now have total of 8 jars/
containers, 4 with crushed food and 4 with decanted acetone drying. Once both sets
of jars dry,
Results:
HOUSEHOLD
FOOD
WEIGHT OF
EMPTY JAR (G)
WEIGHT OF JAR +
CRUSHED FOOD
(G)
WEIGHT OF
CRUSHED FOOD
ALONE (G)
Example calculation
only
105g 116g 116-107= 11g
Chocolate chip 49.2g 57.6g 8.4g
Potato chips 53.4g 62g 8.6g
Sunflower seeds 55.7g 64.1g 8.4g
almonds 55.8g 64.5g 8.7g

ESSENTIALS OF CHEMISTRY (CHM101) 4
DAY 2
1. Once the acetone has evaporated, take the jars with food remains and measure the
weight again. Record the mass in the Day 2 table provided.
2. Now take a look at the evaporated acetone and the fatty residue that remained.
Carefully observe its appearance and record your observations in the table provided.
3. Lastly, take a photo of your jars showing the residues from the acetone solutions,
as shown in the images below:

ESSENTIALS OF CHEMISTRY (CHM101) 5
Results:
HOUSEHOLD
FOOD
WEIGHT OF JAR
WITH DRIED
FOOD (G)
WEIGHT LOST
FROM FOOD(G)
%LIPID
EXTRACTION
Example calculation
only
113g 116(day 1)- 113g= 3g (3G/11G)*100%=
27%
Chocolate chip 57g 0.6g 7.1%
Potato chips 61.1g 0.9g 10.4%
Sunflower seeds 62.98g 1.12g 13.3%
Almonds 63.19g 1.4g 16%
The weight of jar with raw food- weight of jar= weight of raw food
The weight of beaker with raw food- weight of jar with dried food= weight lost from the food
The weight lost from food÷ weight of raw food×100 = % of lipid extracted (Smith, 2009)
Results of day 2 observations of fat residues from decanted acetone jars:
HOUSEHOLD FOOD COLOUR TEXTURE/VISCOSITY
Chocolate chip Light brown color Waxy texture
Potato chip Light yellow color Oily texture
Sunflower seeds Yellow color oily texture
Almonds Light yellow color Oily texture
ADDITIONAL QUESTIONS
Q1. From Part 1, you may have observed spots on the paper. Is it fat residue or water? How
can you tell? Explain.
Solution:
Its fat residue because the paper is transparent and greasy when touched.

ESSENTIALS OF CHEMISTRY (CHM101) 6
Q2. (a) Copy the % lipid content from above into this table, and rank your 4 foods from
lowest to highest percentage of extracted fat.
Solution:
Rank of foods from lowest to highest fat content
1. Chocolate chip 7.1%
2. Potato chip 10.4%
3. Sunflower seeds 13.3%
4. Almonds 16%
(b) Look at the food packages (dietary food information) to work out total % fat, and rank the
foods (1 to 4) in the table below from lowest % fat being 1 to highest 4.
(c) How does the % fat and ranking from your tests compares to what is expected based on
the packaging?
Solution:
From the Nutrition facts 28g of almonds contain 17g of fat, 28g of sunflower seeds comprise 15g
of fat, 28g of potato chips comprise 10g of fat and 28g of chocolate chips comprise 8g of fat.
This result show that the ranking is consistent with the packaging nutrition facts.
HOUSEHOLD FOOD YOUR RESULTS (A) %
LIPID RANK (1-4)
DIETARY INFO (B)
%LIPID RANK (1-4)
Chocolate chip 1 1
Potato chip 2 2
Sunflower seeds 3 3
Almonds 4 4
Q3. (a) Based on your understanding of what is saturated and unsaturated fat, for each food
determine which type of fat they have more of. How did you come to this conclusion?
Solution:

ESSENTIALS OF CHEMISTRY (CHM101) 7
HOUSEHOLD FOOD SATURATED/UNSATURATED EXPLANATION
Chocolate chip Saturated fatty acids had coarse texture, solid
viscosity and changing in
odor
Potato chip Unsaturated fatty acids extracted oil from the potato
chips had smooth texture,
medium viscosity and no
changing in odor and color
Sunflower seeds Unsaturated fatty acids Oil extracted from the
sunflower seeds had smooth
texture, solid viscosity, no
changing in color, but
changing in odor
Almonds Saturated Oil extracted had coarse
texture
(b) Does the predominance of saturated and unsaturated fats from your tests agree with the
dietary information?
ANSWER:
Yes
Q4 When designing and working through an experiment it is important to consider any
limitations or likely source of error that may arise through the experimental design. This
allows the scientist to consider how their observed data may be affected. What sources of
error or limitations may be present in this experiment and what effect will they potential
have on the observed results?
ANSWER:
 The acetone amount used may vary because its not measured this may lead to different
results.
 The time left for drying varies thus errors may occur.
Q5 In this practical, the solvent used to extract the fat was acetone – why was acetone an
appropriate choice of solvent, why would water not be suitable for this task?
Hint: consider the principles of solubility
ANSWER:
The extraction is efficient with acetone as compared to other solvents thus efficient results.
Water cannot dissolve fats effectively, lipids are sparingly soluble in water thus it is not used in
this experiment (Mattes, 2007).

ESSENTIALS OF CHEMISTRY (CHM101) 8
CONCLUSION
The brown paper bag was used to check the presence of lipids in the four foods, almonds,
sunflower seeds, chocolate cookies and potato chips. When the foods were heat fat came out. A
dark wet translucent spot indicated the presence of fats. We extracted lipids from the food it was
discovered that almonds have the most lipids, followed by sunflower seeds, then potato chips,
and the least chocolate cookies. Almonds have the peak percentage of lipid extraction. From the
experiment we are able to tell which food contains saturated fatty acids and which one contains
unsaturated fatty acids by observing the odor, color, texture and viscosity of the fats extracted
from each food. The extracted oil from the chocolate cookies and almonds have coarse texture,
solid viscosity and changing in odor so we conclude that they contain saturated fatty acids.
Unlike the first one, the extracted oil from the potato chips have smooth texture, medium
viscosity and no change in odor and color so we conclude that they have unsaturated fat. The
extracted oil from the sunflower seeds has smooth texture, solid viscosity, no change in color but
a change in odor so we conclude that the sunflower seeds contain both unsaturated and saturated
fats.
REFERENCES
Elias, S. L., & Innis, S. M. (2008). Bakery foods are the major dietary source of trans-fatty
acids among pregnant women with diets providing 30 percent energy from fat. Journal of the
American Dietetic Association, 102(1), 46-51.
Smith, T. G., Chouinard, H. H., & Wandschneider, P. R. (2011). Waiting for the invisible
hand: Novel products and the role of information in the modern market for food. Food
Policy, 36(2), 239-249.

ESSENTIALS OF CHEMISTRY (CHM101) 9
Smith, T. G., Chouinard, H. H., & Wandschneider, P. R. (2009). Waiting for the Invisible
Hand: Market Power and Endogenous Information in the Modern Market for Food.
Mattes, R. D. (2007). Effects of linoleic acid on sweet, sour, salty, and bitter taste thresholds
and intensity ratings of adults. American Journal of Physiology-Gastrointestinal and Liver
Physiology, 292(5), G1243-G1248.