Food Tests Flashcards
how do you prepare a food sample
1) get a piece of food and break it up using a pestle and mortar
2) transfer the ground up food to a beaker and add some distilled water
3) stir it with a glass rod to dissolve some of the food
4) filter the solution using a funnel lined with filter paper
what is the test for sugars
benedict’s test
what are the two types of sugars
non reducing and reducing
how do you do the benedict’s test
prepare a food sample and transfer to a test tube
prepare a water bath at a temp of 75
add some benedicts solution using a pipette
place the test tube in with a test tube rack
if it turns from blue to green, brick red, or yellow a reducing sugar is present
what is an example of food with sugar
bread
what is the test for starch
iodine solution
how do you do the iodine test
make a food sample and transfer to a test tube
add a few drops and shake. if starch is present it will turn from browny-orange to black or blue black
what is an example of food with starch
potatoes
what is the test for protein
biuret test
how do you do the biuret test
if it contains protein the solution will change from blue to pink or purple
what is an example of food with protein
cheese
what is the test for lipids
sudan III test
how do you do the sudan III test
if the sample contains lipids it will separate into 2 layes. the top layer will be bright red
what is an example of food with lipids
milk
