Postharvest involves ‘developing practices to maintain and enhance quality after harvest’. 

The three main objectives of applying postharvest technology to harvested fruits and vegetables are:
• to maintain quality (viz. appearance, texture, flavour and nutritive value).
• to ensure food safety, and
• to reduce losses (both physical and in market value) between harvest and consumption. (1)

Fruit, vegetables and ornamentals are ideally harvested when eating and visual quality are at an optimum.  However, since they are living biological systems, they will deteriorate after harvest.  The rate of deterioration varies greatly between individual products depending on their overall rate of metabolism, but for many it can be rapid. 

For short supply chains, where produce is transferred from farm to end user in a short period, the rate of postharvest deterioration is generally of little consequence.  However, with the increasing distance of food production areas from population centres that often have complex marketing systems, and the increasing growth of global supply chains, the time from farm gate to end user is in some instances increasing. Add to this predicament the trend to store produce for longer periods in order extend the marketing period into a time of shorter supply, and thereby be able to command a higher price, it is little wonder that establishing good postharvest handling is critical for a successful company/industry. 

The actual causes of postharvest loss are many, but can be classified into two main categories.  The first category is physical loss or damage.  This can arise from structural damage, including microbial wastage, which can leave produce tissue degraded to a stage where it is not acceptable for presentation, fresh consumption or processing.  Physical loss can also arise from the evaporation of intercellular water, which leads to direct loss in weight and reduced returns. 

The second category is loss of quality.  This can be due to physiological and compositional changes that alter the appearance, taste, flavour and/or texture and make produce less aesthetically desirable aesthetically to end users.

Australia’s geographic isolation from our overseas markets means that a high priority must be placed on maintaining the quality of our products during storage and shipping.  Thousands of tonnes of produce are transported daily over long distances within Australia and internationally.  Fresh fruit, vegetables and ornamentals are important items of commerce, and there is a large investment of resources in storage, transport and marketing facilities designed to maintain a continuous supply of these perishable commodities.  Postharvest technology aims in part to protect that investment.

Thus, postharvest research encompasses a wide range of topics and, all links within the horticultural produce supply chain.  Click here to read more.

Source:

1. Postharvest – An Introduction to the Physiology & Handling of Fruit, Vegetables & Ornamentals, Wills, McGlasson, Graham & Joyce, 4th edition.