01-Post-Harvest_Part II

Post-Harvest Factors

Factors that affect the respiration rate of harvested crops after they have been harvested.

Atmospheric Composition

The composition of gases in the surrounding environment, which can affect the respiration rate of harvested crops.

Temperature

The level of heat or coldness in the environment, which can affect the respiration rate of harvested crops.

Stress

Any physical or physiological factor that causes strain or tension on the harvested crops, which can affect their respiration rate.

Ripening

The process by which fruits and vegetables become fully mature and develop their characteristic flavor, texture, and color.

Temperature affecting respiration rate

Affects its growth rate, enzyme activites, respiration, and photosynthesis

Abiotic Stress

• Heat / Cold

• Flooding / drought

• Imbalance or nutrients / salt

Biotic Stress

• Pathogens

• Insects

• Herbivores

Ethylene Biosynthesis Pathway

The series of biochemical reactions in plants that lead to the production of ethylene gas, a plant hormone involved in the ripening process.

Ethylene

A plant hormone that controls growth and development, including the ripening process.

Ethylene Sensitive

Fruits or vegetables that are highly responsive to ethylene gas and can be affected by its presence.

Ethylene Producer

Fruits or vegetables that produce and release ethylene gas.

Ethylene Inhibitor

A substance or treatment that can inhibit or slow down the production or effects of ethylene gas.

Maturity Index

A set of factors used to determine the optimal time for harvesting horticultural commodities based on consumer purpose and the type of commodity.

Harvest Maturity Indices

Various methods, including computational, physical, chemical, and physiological, used to determine the maturity of crops for harvest.

Starch Staining Patterns

Patterns observed in the staining of starch in apples, which can indicate the maturity stage of the fruit.

Head Solidity/Density

The firmness and compactness of the head or top part of certain crops, which can indicate their maturity.

Guidelines for Harvesting

Crops should be :

• at their highest peak when reached to consumer hands

• mature that develop acceptable flavor and appearance

• be market size

• no toxic substances

• maintain adequate storage life

Harvesting methods

Hand harvesting

Mechanical harvesting (mechanical assistance, harvesting machines)

Handling of Harvest Crop

The proper handling practices for harvested crops to minimize weight loss, deterioration, respiration rate, and contamination

Can be done by in-field packaging or pack house operations.

Pack-House Operation

The operations and processes involved in preparing harvested crops for market, including packing, sorting, and grading.

Pre-cooling or cooling

To extend the storage life of the harvest crops.

Can be done by refrigeration, room cooling, forced-are cooling, spray cooling, ice cooling or liquid N2

Curing method

Used to allow tuber crops to heal their injury from harvesting.

Process of allowing air to dry the crops for 10 to 14 days.

TTS (Brix)

Total soluble solids, a measurement of the sugar content in a solution.