Which from following statements is NOT correct regarding tannins?
- These avoid browning of freshly cut potato.
- These are formed from polyphenols.
- These are obtained by polymerisation of quinones.
- These are generated after cutting fruits or vegetables.
Solution
The browning process in plant tissues involves tannins and related phenolic compounds. When cells are damaged, enzymes oxidize these phenolics to quinones, which then polymerize into melanins. This mechanism indicates tannins are contributors to browning, not preventatives.
Tannins are polyphenolic compounds formed biosynthetically from simpler phenolic precursors, not from polymerization of quinones. Quinones are instead products of tannin oxidation during browning.
These compounds exist naturally in plant tissues prior to cutting; they are not generated afterward. Cutting merely releases them, facilitating enzymatic reactions.
Among the options, C inaccurately describes tannins as polymers of quinones, contradicting their true chemical nature and biosynthesis.
The correct identification is: $\boxed{C}$
Asked in: MHT CET 2025 (05 May Shift 2)