Question

"Brown Heart Disorder" in Apples is due to the accumulation of toxic substances, if

• A. $O_2$ supply increased during storage
• B. $O_2$ supply decreased during storage
• C. $CO_2$ supply increased during storage
• D. $CO_2$ supply decreased during storage

Hint:

Internal browning in storage is almost always a $CO_2$ toxicity issue.
Lowering the storage temperature can sometimes aggravate this if ventilation is poor.

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
"Brown Heart" is a physiological storage disorder in apples. The question asks what atmospheric condition during storage triggers this disorder.
Detailed Explanation:

• Controlled Atmosphere (CA) Storage:
Apples are often stored in environments with low Oxygen and high Carbon Dioxide to slow down respiration and ripening.

• Toxicity of $CO_2$:
If the Carbon Dioxide ($CO_2$) concentration becomes excessively high (usually above \(5\%\), depending on the variety), it becomes toxic to the fruit tissue.
This high $CO_2$ inhibits certain respiratory enzymes (like succinate dehydrogenase), leading to the accumulation of metabolites like succinic acid, which damages the internal cells.

• Symptoms:
The internal core and flesh of the apple turn brown and become soggy/water-soaked, while the exterior of the fruit may appear perfectly normal. This is known as "Brown Heart."

Step 3: Final Answer:
Brown Heart disorder is caused by high levels (increased supply) of $CO_2$ during storage.