Question

Tagatose is an “artificial” sweetner that is similar to sucrose in sweetness and replaces sucrose in Pepsi slurpees. Tagatose is a C4 epimer of fructose and is found to occur naturally.

a) Draw the structure of D-Tagatose

b) L-Tagatose is also about as sweet as sugar but costs more to manufacture than its D-isomer; thus an early decision to market L-Tagatose was abandoned. Draw the structure of L-Tagatose

c) Where can Tagatose be naturally found and how is it produced commercially?

d) Why is tagatose an effective substitute for other sugars?

Answer 1

Ans a) Structure of D- tagatose

Ans b) Structure of L- tagatose

Ans;-c) Tagatose can be naturally found in cow's milk and fruits like apples, pineapples etc

Commercially tagatose can be produced in two step process

Step 1) Since tagatose is present in milk , so at first Lactose is hydrolysed in presence of an enzyme lactase to produce D- galactose and D-glucose

Step 2) D- galactose on isomerization in presence of Ca(OH)₂ produces D- tagatose

Ans d) Tagatose is an effective substitute for other sugar because it has very low calorie and it does not affect the insulin secretion of the body. Also it easily breaks down into glucose and stores in the form of energy in the body.