Prevent Deterioration of Perishable Crops

The Bureau of Postharvest Research and Extension (BPRE) advises farmers to prevent the deterioration of perishable crops like fruits and vegetables. The products must be of good quality even before harvest. This is because production practices have a tremendous effect on crop quality. This quality must be maintained through appropriate postharvest handling as they reach the consumers.

BPRE specialists tell us that recommended postharvest handling technologies and practices can no longer cure prior damage and injury suffered by the harvest. Farmers must understand that respiration, loss of moisture, and microbial growth induce quality deterioration of perishable crops. Thus, these must be minimized to attain optimum shelf life of fruits and vegetables.

During respiration, sugars, fats, proteins and other food reserves in the product are converted into metabolic energy needed to keep plant tissues alive and functioning. Since respiration uses oxygen and produces carbon dioxide and water vapor, the respiration rate of a product determines its transit and postharvest life. The higher the rate of respiration, the faster the product losses moisture, and the faster it deteriorates.

High temperature, bruises, injuries and stress cause faster respiration, resulting in shriveling, discoloration, senescence, and loss of market value.

Microorganisms multiply rapidly on vegetables and are prolific over a wide range of temperature and relative humidity. Their presence results in unpleasant smell and taste, and generates heat that hastens respiration.

To maintain high quality of fruits and vegetables, here are some tips on harvesting and packing.

Harvesting
• Harvest at the coolest time of the day, usually in the early morning, to minimize deterioration and water loss.

• Harvest the crop at the optimum stage of maturity because immature or overmature products may not last in storage.

• Use clean (sanitized) harvest containers to minimize the spread of decay pathogens.

• If possible, pack the harvest right in the field to prevent further physical damage.

• Avoid or reduce damage by gentle and minimized handling. Bruises and other mechanical damages do not only affect the appearance but also provide entrance for decay or
ganisms.

Packing
• Trim the unwanted parts (excess outer leaves, and discolored or damaged parts), which would be likely rejected by consumers, shorten shelf life, and increase chances of injury.

• Clean the product by soaking, washing, wiping, brushing and drying to prevent pathogen buildup and contamination.

• Dry or remove excess external moisture, which might promote diseases especially at high temperature and humidity.

• Sort and classify products according to size, weight, shape, appearance and other physical attributes. Sorting minimizes the spread of diseases and premature ripening. It also reduces packaging, transport and handling costs.

• Pack produce in properly cleaned shipping containers to minimize bruising and damage.

• Pre-cool the product at lower temperature before shipping to maintain fresh appearance, prevent decay and extend its shelf life.

• Store the product at ideal conditions to minimize quality loss.