Subtopic: Controlled and modified atmosphere storage
Question Statement:
In Controlled Atmosphere (CA) storage of apples, maintaining $O_2$ levels around $2\text{--}3\%$ and $CO_2$ levels around $2\text{--}5\%$ at $0\text{--}2^\circ\text{C}$ provides which of the following physiological benefits?
Options:
(A) Substantially suppresses fruit respiration rate and slows down senescence
(B) Inhibits autocatalytic ethylene biosynthesis and chlorophyll degradation
(C) Eliminates all risk of chilling injury regardless of storage temperature
(D) Retards flesh softening by reducing the enzymatic activity of polygalacturonase
Answer Key:
A, B, D
Step-by-Step Solution & Explanation
Low $O_2$ and elevated $CO_2$ suppress respiration (A), inhibit ethylene synthesis (B), and slow pectin breakdown by polygalacturonase (D). Option C is INCORRECT; gas atmosphere modification does not eliminate chilling injury if stored below the fruit's critical chilling threshold.