Question

Solanine is a toxic glycoalkaloid that develops in potatoes when they are exposed to ______.

• A. High humidity
• B. Extreme cold
• C. Light
• D. Low oxygen

Hint:

Light exposure causes potatoes to produce green chlorophyll and toxic solanine at the same time. Always discard green-skinned or heavily sprouted potatoes, as they contain high levels of solanine.

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
The question asks to identify the environmental trigger that causes potatoes to synthesize solanine, a toxic glycoalkaloid compound.

Step 2: Detailed Explanation:

• Glycoalkaloids in Potatoes: Potatoes (Solanum tuberosum) naturally produce low levels of toxic glycoalkaloids, primarily solanine and chaconine, concentrated in the skin as a natural defense mechanism against pests.

• The Effect of Light Exposure:

• When potatoes are exposed to natural or artificial light during storage, display, or handling, they undergo a process called "greening."

• Light exposure stimulates the synthesis of chlorophyll, which turns the skin green. Chlorophyll itself is non-toxic.

• Simultaneously, light exposure stimulates a stress response that triggers a rapid increase in the synthesis of glycoalkaloids like solanine.

• Toxicity and Risk: Solanine is a potent neurotoxin that inhibits acetylcholinesterase and disrupts cell membranes. High levels of solanine cause gastrointestinal distress and neurological symptoms in humans. Because greening and solanine synthesis are both triggered by light, green spots on potatoes are a visual warning of high solanine levels.

Step 3: Final Answer:
Solanine synthesis in potatoes is primarily triggered by exposure to light, making option (C) the correct choice.