Post-Harvest Technology Flashcards
6 cards from real Agricultural/Bioengineering practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Post-Harvest Technology flashcards as text
What is the primary purpose of grain drying in post-harvest management?
Answer: Reduce moisture to safe storage levels and prevent spoilage
Drying reduces grain moisture below the threshold (typically 13–15%) at which mold, insects, and bacteria thrive.
Equilibrium moisture content (EMC) of grain is defined as the moisture level at which:
Answer: Grain neither gains nor loses moisture to the surrounding air
EMC is reached when the vapor pressure of grain moisture equals that of the surrounding air, resulting in no net moisture transfer.
Which type of grain dryer passes heated air upward through a moving grain column?
Answer: Cross-flow dryer
In a cross-flow dryer, heated air moves horizontally through a vertically moving grain column, which is the most common commercial design.
Controlled atmosphere (CA) storage of fresh fruits and vegetables involves modifying which gases?
Answer: Oxygen and carbon dioxide
CA storage reduces O₂ and increases CO₂ levels to slow respiration and delay ripening of fruits and vegetables.
The process by which fresh produce continues to consume oxygen and release CO₂ after harvest is called:
Answer: Respiration
Post-harvest respiration is the metabolic process that consumes stored carbohydrates and generates heat, reducing shelf life.
Heat of respiration from stored grain is a concern because it can cause:
Answer: Hotspots that accelerate mold growth and grain deterioration
Localized heating (hotspots) in grain bins accelerates moisture migration and mold development, leading to grain spoilage.