Question

Laevulose present in honey is
A. Disaccharide
B. Glucose
C. L-fructose
D. Pentose

Answer 1

Hint: Natural honey has a complex and heterogeneous composition. The components are directly dependent on the weather condition, the soil, the type of vegetation etc. It is a concentrated water solution of two sugars, laevulose and dextrose. Also it has small quantities of at least 22 other more complex sugars. The prefix levulo comes from the latin- meaning left.

Complete answer:
Honey contains: nitrogenous compounds, mineral substances, water, carbohydrates, plant antibiotics or phytoncides, alkaloids, biogenic simulators, ferments or enzymes, hormonal substances, organic acids, essential oils, , antioxidants, aromatic volatile, cancer and antitumor agents, and other components that are still unknown.
Glucose and fructose are present in a high percentage in the overall composition of the honey and in the carbohydrate composition. In honey they comprise the invert sugar that reaches up to 80% (in some types of honey it goes up to 90%). Crystallization process in honey is greatly dependent on the proportion between these two monosaccharides.
L-fructose and glucose can also be referred to as laevulose and dextrose respectively. As they have the same chemical formula, these two sugars are structural isomers. The names laevulose and dextrose refer to their effect on the plane-polarized light. Due to the difference in the arrangement of atoms in dextrose, it rotates the plane-polarized light to the right, while laevulose rotates the light to the left.

Hence, the correct answer is option (C).

Note: One of the characteristics that make honey different from other sweetening agents is the presence of the enzymes. These enzymes conceivably arise from the pollen bee, nectar, or even micro-organisms or yeasts in the honey, in which most prominent are added by the bee. The complex protein material that under mild conditions brings about chemical changes that may be difficult to accomplish artificially without their aid is known as enzymes. Some of the important honey enzymes are glucose oxidase, diastase and invertase.