B3 - food tests RP

Question 1

what is the purpose of the food test required practical

Answer 1

to find out whether starch, sugars or proteins are present in samples

Question 2

what is the risk assessment for the food tests required practical

Answer 2

• hot water bath - could burn yourself or scald yourself so remain cautious
• chemicals are being used which can be irritant - wear eye protection and wash hands immediately after spillage

Question 3

what is the test for starch

Answer 3

• add iodine to the substance
• look for colour change
• if starch is present it will go from orange/brown to blue/black

Question 4

what is the test for sugar

Answer 4

• add Benedict’s solution to the substance
• heat in a boiling water bath for 2 minutes
• look for colour change
• if sugar is present it will go from blue to brick red (green, yellow or orange if a little is present)

Question 5

what is the test for protein

Answer 5

• add Biuret’s solution to the substance
• look for colour change
• if protein is present, it goes from blue to purple

Question 6

what is the test for lipids

Answer 6

• add ethanol to the substance
• shake thoroughly
• add water
• look for colour change
• if lipids are present, goes from clear to cloudy/milky

Question 7

what is a quantative test

Answer 7

a test that shows whether a particular substance is present

Question 8

how could mistakes be made in the food tests required practical

Answer 8

• contamination e.g. same chopping board for different substances
• can be subjective - based on human judgement - people may see colours differently