Grade 7: Chemistry

Detection of starch and Fat in different food items:
A fun filled activity was carried out with the students of grade 7. The students collected food samples from their Tiffin. A drop of iodine was put on each food sample to detect the presence of starch. Appearance of a bluish black color on the foodstuffs confirmed the presence of starch.
Foods such as wadas, samosas, chips, chiwda, etc. were tested for the presence of fat. Students put some food on a piece of paper and mashed it. Oily foods left a translucent mark on the paper.
Students enjoyed collecting food samples. They understood that
a) Foods containing starch come mainly from plants whereas foods without starch come mainly from animals.
b) Oily foods leave a translucent mark when put on paper.