Extraction of Invisible Lipids from Common Snacks

There are two types of fats present in the foods we eat, i.e. visible and invisible fats. From the word itself, the former refers to fats that can be seen such as those in butter, the cooking oil, and extracted oil from cooking meat. Invisible fats, on the other hand, cannot be seen by the naked eye. It hides in foods like eggs, pastries, confectionery, and snacks.

Photo: Obtained fats from potato chips, sunflower seeds, and chocolate chips. (photo credit: E. Fuentes)

Laboratory Procedure for Extraction of Invisible Lipids from Potato Chips, Chocolate Chips, and Sunflower Seeds:

( obtained from the laboratory report of Chemical Engineering students: R. Barcenas, J. Cas, S.G. Perez, and E. Fuentes).

Materials and Methods

Materials:

Materials	Specification	Quantity
Chocolate chips	Semi-sweet Chocolate Droplets (brand)	7 grams
Potato chips	Jack n’ Jill (brand)	7 grams
Sunflower seeds	No brand	7 grams
Analytical balance		1
Microwave		1
Paper towels		1 ply
Acetone		60 mL
Petri dishes	100 mm	3
beaker	50 mL	3
Stirring rod	glass	1
Graduated cylinder	glass	1
hammer		1
Aluminium foil

Procedures:

·         The samples, i.e., potato chips, chocolate chips, and sunflower seeds were purchased in the supermarket. For the visual evidence of invisible fats from foods, heat was used. The three samples were heated in a microwave. For the quantitative measurement of fats, acetone was used. The experiment was done for one trial.

A.   Cleaning of the Work Area

Materials such as analytical balance, paper towels, acetone, foil, hammer, chocolate chips, sunflower seeds, and potato chips were prepared and organized on the work stat. Petri dishes, graduated cylinder, beakers and stirring rod were washed with dishwashing soap and were dried using paper towels.

B.   Preparation of Materials

      The workstation was cleaned using liquid Lysol and a clean rug. Next, it wasdisinfected with Casino Ethyl Alcohol. The cleaning process was done once.

C.   Weighing of Samples

The analytical balance was switched on and a sheet of paper towel was placed on it. The balance was tared. Two grams of the potato chips were weighed. The paper towel with potato chips was removed from the balance and was set aside. A new set of paper towel was placed on the analytical balance and tared again. Five grams of the same potato chips were weighed. It was also set aside. The same process was followed for chocolate chips and sunflower seeds. Two grams and five grams were weighed separately for each sample.

D.   Crushing of Samples into Smaller Pieces

The group cut a piece of foil from its roll (approximately 10”x4” inches). The piece of foil was folded into two and the weighed five grams of potato chips were placed in between. The chips were crushed using hands and were further hammered lightly with the handle of the scissors. The same went for chocolate chips and sunflower seeds weighing five grams. However, a metal hammer was used for the latter instead.

E.   Transferring of Crushed Samples to Beakers

Using white masking tape and a pen, the beakers were labelled as follows: potato chips, chocolate chips, and sunflower seeds. A beaker was weighed on the balance. The datum was recorded. The crushed potato chips sample in the foil was carefully transferred to the beaker labelled “potato chips”. The crushed chocolate chips and sunflower seeds were also transferred to their respective beakers. Each beaker with sample was weighed and the data were recorded. The mass of the empty beaker was subtracted from the mass of each beaker with crushed sample. The new mass of each sample was obtained.

F.    Treating each Sample with Acetone

10 mL of acetone was measured using the 10 mL graduated cylinder. It was immediately but carefully poured to the beaker with potato chips. The said beaker was brought to the fume hood. It was stirred using a glass rod for one minute. The acetone was poured into a petri dish leaving the potato chips in the beaker. Another 10 mL acetone was measured using the graduated cylinder and was immediately poured into the beaker. It was once again stirred using the rod. After one minute, the acetone was poured into the same petri dish. This was done to extract maximum fats that could be extracted. The same process was done for the chocolate chips and sunflower seeds. Separate petri dishes served as the container for each sample. Also, the stirring rod was washed first before using it for stirring the other samples.

G.   Evaporating the Acetone

The petri dishes with acetone and the beakers with samples were organized in the fume hood and were left there for approximately 22 hours (overnight).

H.   Heating the Sample in Microwave

The weighed two grams of sunflower seeds and potato chips were microwaved for 25 seconds. For each sample, the paper towel was folded enclosing the seeds/potato chips right after it was removed from the microwave. It was set aside for five minutes. The same process went for the chocolate chips, however, it was microwaved for 40 seconds instead. Then, the paper towel was opened up revealing wet-like spots. Observations were made in terms of color, texture, odor and viscousity. The information was recorded.

I.      Cleaning of the Work Station

Pieces of waste on the work station were removed and disposed. Other materials were packed to clear the area. It was cleaned using Lysol, rug, and ethyl alcohol.

J.    Results on Dried Samples

The group visited the laboratory the next day to check on the beakers with samples and petri dishes. Then, it was weighed and recorded. Observations were also made.

K.   Cleaning of Laboratory Equipment

The fluid in petri dishes were transferred to a plastic bottle for wastes. The contents of the beaker were also disposed. The laboratory materials used were washed with dishwashing soap and dried using paper towels. The materials were returned to the chemical technician.