INVESTIGATORY PROJECT CLASS 12 CHEMISTRY

1. THEORY
Food materials undergo natural changes due to time,temperature and enzymatic action.
So these changes become unfit for use.These changes can be checked by adding small
amounts of potassium bisulphite. The effectiveness of KHSO3as preservative depends
upon its concentration under different conditions which may be determined
experimentally.
Preservatives are a food safety measure used to prolong shelf life and keep foods from
spoiling.Potassium bisulphite is a food additive that inhibits the growth of bacteria, mold
andyeast, and it helps prevent food discoloration.
Potassium bisulphite,also spelled "bisulfite,"is sometimes referred toas asulfite salt;it falls
intothe same category of food additives such assodium sulfite, potassium sulfite and
sodium bisulfite. Potassium bisulphite is a white powderthat dissolves inwater butnotin
alcohol. Unlike other sulfur salts suchas sodiumsulfite, potassium bisulphitehas a sulfur
smell.
PROCEDURE
1)Take Freshfruits,washthem thoroughlywithwaterand peeloff theirouterCover.
2)Grind ittoa pastein themortar withapestle.
3)Mix withsugar andcolouring matter.
4)The material soobtainedis fruit jam.It maybe usedtostudytheeffect ofconcentration of
sugar andKHSO3,temperature andtime.