biology lab report
Objective:
To find out the food substance in food sample X,Y and Z.
Biological Principle:
Test for lipids using the grease spot test
Test for glucose using Clinistix paper
Test for reducing sugars using Benedict’s test
Test for starch using the iodine test
Test for proteins using Albustix paper
Test for vitamin C using DCPIP solution
A control using distilled water instead of the sample should be included.
Independent: different types of food samples
Dependent: different types of food substance presence in food sample
Assumption:
Controlled: using the same amount of food sample in different test
Procedure:
Solid: Grind the food with distilled water. Squeeze the ground materials through layers of muslin.
Liquid: Put 1 cm3 of the liquid food sample into test tubes.
-grease spot test:
A drop of liquid food sample was added to a filter paper and was let to dry for 5 minutes.
The filter paper was held up to the light and any translucent spot was observed.
The filter paper was put into an organic solvent. it was taken out and let to dry
The filter paper was examine against light again.
(positive result – translucent spot disappears)
-Clinistix paper:
A drop of liquid food sample was added to the well of a spot plate
The Clinistix paper was dipped into the sample and any colour change was observed.
(positive result –change from pink to purple)
-Benedict’s test:
Equal volumes of liquid food sample and Benedict’s solution were mixed.
The mixture was boiled for 5 minutes and any change in it was observed.
(positive result – brick-red precipitate forms)
-iodine test:
A drop of liquid food sample was added to the well of a spot plate
A drop of iodine solution was added to the sample and any colour change was observed.
(positive result – change from brown to blue-black)
- Albustix paper
A drop of liquid food sample was added to the well of a spot plate
The Albustix paper was dipped into the sample
To find out the food substance in food sample X,Y and Z.
Biological Principle:
Test for lipids using the grease spot test
Test for glucose using Clinistix paper
Test for reducing sugars using Benedict’s test
Test for starch using the iodine test
Test for proteins using Albustix paper
Test for vitamin C using DCPIP solution
A control using distilled water instead of the sample should be included.
Independent: different types of food samples
Dependent: different types of food substance presence in food sample
Assumption:
Controlled: using the same amount of food sample in different test
Procedure:
Solid: Grind the food with distilled water. Squeeze the ground materials through layers of muslin.
Liquid: Put 1 cm3 of the liquid food sample into test tubes.
-grease spot test:
A drop of liquid food sample was added to a filter paper and was let to dry for 5 minutes.
The filter paper was held up to the light and any translucent spot was observed.
The filter paper was put into an organic solvent. it was taken out and let to dry
The filter paper was examine against light again.
(positive result – translucent spot disappears)
-Clinistix paper:
A drop of liquid food sample was added to the well of a spot plate
The Clinistix paper was dipped into the sample and any colour change was observed.
(positive result –change from pink to purple)
-Benedict’s test:
Equal volumes of liquid food sample and Benedict’s solution were mixed.
The mixture was boiled for 5 minutes and any change in it was observed.
(positive result – brick-red precipitate forms)
-iodine test:
A drop of liquid food sample was added to the well of a spot plate
A drop of iodine solution was added to the sample and any colour change was observed.
(positive result – change from brown to blue-black)
- Albustix paper
A drop of liquid food sample was added to the well of a spot plate
The Albustix paper was dipped into the sample