Postharvest Biology and Technology: Deterioration Factors

In the field of agriculture, when we talk about postharvest handling, we talk about the stage of crop production right after harvest. It includes the following stages:

 Cleaning

 Cooling

 Sorting

 Packing

Having knowledge in postharvest biology and technology is crucial in determining the final quality of the produce whether it is sold fresh for consumption or used as ingredients for processed food products.

Since fresh fruits, vegetables and ornamentals are all composed of living tissues, it is normal for them to undergo changes. Most of these changes may not be desirable in the consumer’s standpoint.

In this article, we will enumerate the biological factors involved in the deterioration of produce.

1. Respiration

Fruits and vegetables store organic materials such as carbohydrates, proteins and fats. These organic components are all subject to a process called respiration. In respiration, these organic materials are broken down into simple end products with a release of energy.

This rate or respiration is directly proportionate to the rate of deterioration or perishability. It’s a good idea to know the respiration rate of each crop to identify which ones perish the fastest.

2. Ethylene Production

The production of ethylene increases with maturity at harvest. When crops are placed on lower temperatures, however, the production rate of ethylene is reduced.

3. Changes in Composition

 Loss of Chlorophyll

 Carotenoids

 Carbohydrates

4. Continuous Transpiration

Transpiration or water loss is a primary cause of deterioration because it affects not only the weight but also the appearance of produce.

5. Physiological Disorders

After harvest, the crops can be exposed to undesirable temperature and physical damage.

 Freezing injuries

 Heat injuries

 Surface injuries

 Impact & Vibration bruising

6. Pathological Damage

One of the most common symptom of perishability comes from activity of bacteria and fungi. There are some cases where pathogens infect healthy plants and become the cause of deterioration

7. Abiotic Factors

There are also environmental factors inducing deterioration.

 Temperature

 Relative Humidity

 Atmospheric Composition

 Ethylene

 Light

 Fungicide application