Q52: Vegetables are blanched before freezing to: - Family Ecology - Human Development and Family Studies- ICAR JRF/SRF 2024 | Agrigyan

• Objective of Blanching Vegetables Prior to Freezing:
• Enzymatic Degradation: Raw vegetable tissues contain endogenous oxidative enzymes, predominantly polyphenol oxidase, peroxidase, catalase, and lipoxygenase.
• Mechanism: Freezing merely retards enzymatic reaction rates but does not stop them; during extended frozen storage, unblanched vegetables develop off-odors, rancidity, tough textures, and browning.
• Blanching: Brief exposure to boiling water ($95 - 100^\circ\text{C}$) or steam for 1–5 minutes inactivates these spoilage enzymes, preserves natural pigments (chlorophyll), and expels intercellular respiratory gases.
• Conclusion: inactivate the enzymes (Option 1).

Correct option: (1) inactivate the enzymes