Question

How many types of sugar are found in fruit juice?

Answer 1

Hint: Sugar is the basic constituent of any fruit juice, but it differs with respect different juices. The proper constituents of fruit juice can be recorded on chromatogram.

Complete step by step answer:
Fruits and its juices are considered to be the healthiest constituent of human diet. Juices mostly contain water, acids, sugar and minerals. Sugars are the most important and common ingredient of all the beverages. These are also used as preservatives. Sucrose, glucose and fructose are mainly the types of sugars found in fruit juices along with other types.
Many methods are recorded to find the constituents of food items (here, fruit juice). The analysis by traditional method is often very complicated and time consuming. So, high precision instruments came into use to overcome the difficulties that arose in the past. These include most importantly used gas chromatography and high-performance liquid chromatography.

Illustration-
Here, the paper chromatography is used to determine the types of sugar. Let us first understand the paper chromatography technique.
Paper chromatography-
As the name suggests, the chromatography technique uses paper sheets (strips) as an absorbent. This would be the stationary phase and the solution running through will be a moving phase. The solution would be the one which needs to be analysed.
When the mobile phase i.e. solution moves through the paper the compounds which are to be separated are absorbed into the pores of stationary phase i.e. paper. Compound separates themselves based on the differences in their affinities towards the stationary phase.
The compounds are detected by the spots they create while they move along the paper from the start line to the solvent front.
In the given problem, if the spots of the two different substances are the same then they contain the same compounds. Since, the spots produced by the fruit juice on the chromatogram are 3. Thus, it constitutes 3 types of sugar. The following two types of sugars i.e. sucrose and glucose match the spots of fruit juice.
Therefore, two types of sugar are found in the given sample i.e. sucrose and glucose.

Note: Chromatography and its analysis is highly precise and concentration demanding (analyser) method as one spot can change the further calculations. So, we should create check points while analysing the same.