Post Harvesting Practices

Post-Harvesting Practices - Crops

Post harvesting technology is described as “all the complex operations supported by biotechnologies that are resorted to, to ensure the optimal conservation of crops during and after harvest and throughout all the stages of handling, storage, packaging, processing and distribution.”

Post harvesting constitutes the end of the harvesting operation and this is the last stage before the product reaches the consumer.

A number of aspects need to be addressed:

• Stage of harvesting
• Handling during harvesting
• Transportation
• Sorting, grading, washing
• Packaging
• Treatments
• Distribution to market

This is done to ensure that the consumers receive a product that will provide value for their money. Most of the vegetables and fruit, being perishable products, deteriorate because of a shortened shelf life caused by…….

• The wrong physiological stage at picking, wrong cultivar choice or variety, poor cultivation practice and pest control.
• Not handling it properly at harvesting or during transportation.
• Heat or cold treatment and storage.
• Washing or wrong treatment.
• Poor packaging and transportation.

Stage of Harvesting

The point of harvesting is determined by the physiological stage of the crop or fruit. It can be measured in Brix or the sugar content of the fruit. A cultivar with a long shelf life will simplify the storage problem.

Handling During Harvesting

It is important that the product does not come in contact with soil during the harvesting process as soil contamination will contribute to the product’s (bad) appearance – thus, make use of picking bags\containers designed for this purpose. It is advisable to harvest early in the morning as the shelf life of withered veggies is shortened. A range of different treatments is needed to prevent deterioration after harvesting.

Transportation

Transportation from the land to the sorting facilities also plays a role in the product’s quality and appearance – thus, the stacking of the bags\containers on each other must be done in such a way that bruising and rubbing is prevented. Transportation to the market is done in cooler (temperature controlled) trucks as a certain temperature must be maintained.

Sorting, Grading, Washing

The pre-preparation of farm produce is very important – the moment a product reached the market, the farmer has no control over the selling price and will rely on the product selling itself. The product must therefore be graded – e.g., same appearance, acidity, and firmness; sorted – e.g., same size, Brix and colour. It is not uncommon for a product to undergo further grading – distributors preparing it for large chains stores or supermarkets.

Washing – especially potatoes – is equally important and done before the sorting process commences. Some produce is washed in treated water, not for the cleaning as such, but to prevent bacteriological deterioration and decay.

Packaging

Packaging – for export - is done in cardboard boxes with absorption layers between the products. For the local market, the packaging is done in plastic or paper bags, depending on the type of product and the market it is intended for. According to regulations – for local and overseas markets -the packaging must display information regarding the producer for tractability of the product.

Treatments

Produce undergoes treatment in regulated storage where the atmosphere is modified or controlled, ultra-low oxygen storage, oxygen and ethylene adsorption is done to prolong the shelf life of the products.

Post Harvesting - Animal Products

Meat producing farm animals are bred and fed on the farm. This includes the post-harvesting process which entails dosage – especially piglets –castration – male lambs - dehorning etc. Although large enterprises (meat) are equipped with abattoirs, the norm is to sell the produce to butchers or feedlots. Cattle are dehorned to prevent injuries during transportation.

Other animal products can be divided into:

Milk

Milk must be cooled down to 5°C as soon as possible and be kept at that temperature during transportation and distribution. Post harvesting treatment of milk involves cooling, pasteurisation and in some cases homogenisation.

Apart from daily fresh milk usage, it is also used for making cheese, yoghurt, Umkumasi, milk powder and long-life milk.

Click here to view a video that explains magnificent milk.

Eggs

Eggs are stored in rooms where the temperature is lower than room temperature. Eggs are sorted according to size and weight and packed in egg containers – 1 dozen, 2.5 dozen or 5 dozen (so-called taxi packs) and in 30 dozen boxes when transported to different distribution points.

Wool and Mohair

After shearing wool is graded in classes according to the length, strength and thickness, measured in micron. The different classes are then baled (pressed) jute bags which are properly marked and identified for traceability before it is sent down to the different wool markets.

It is very important for the producer to ensure the product is correctly classed to prevent penalties. The producer should also ensure that there is no contamination of the product with foreign materials such as plastic, baling twine or plant (weed) seeds.

Post Harvesting Practices are Evaluated and Adjusted Where Necessary

There are various organisations, local or international, that set standards for the different products. The following organisations are involved in the setting of standards:

The aim is to ensure a better quality product, reduce losses and obtain higher prices and higher net returns and continuous access to the markets.

The producers are normally held responsible for the quality of the product from the production point to the delivery at the market. When the product is collected on the farm or where the product is delivered to the workstation of a cooperative packing facility, it becomes a shared responsibility.

Good Health and Hygiene Principles

Hygiene is very important when working with fresh produce or perishable products. Hygiene can be divided into different categories:

To evaluate the hygiene, quality and post-harvest practices the producer should do the following.

1. Draw up a checklist to evaluate the different processes and stages of post-harvesting activities. The checklist should be used to promote responsibility, accountability, eliminate problems and measure work performance.
2. Keep records of production, classifications, and damaged products. Find ways to reduce the damaged products, thus improving the percentage packed.
3. Keep records of the different classes (%) that was attained from each cultivar or from each land. Draw graphs to illustrate the records.
4. Important to keep records of the selling prices from the different markets for the different products as well as discarded produce. Determine the cause to be able to take precautionary steps during the next season.

Health and hygiene regulations and legislations are reviewed, and changes are integrated into the procedures. The farmer (management) and downwards to the lowest levels of workers must know these regulations and legislation regarding the products that are handled. Incentives should be linked to the marketable percentage (%) of the crop and the prices received for the quality products.

The whole production team must take responsibility for the product as every section contributes to the success of the product. It is a team effort and should be seen as a holistic process that cannot be fragmented as each one plays a very specific role and must be involved in the production process to understand the importance of his\her action.

An illustration of the different role players in the production process;

Products are Evaluated and Quality standards are Adjusted Accordingly

The producer must always be responsive to changes and market tendencies to improve either the quality and quantity or cultivar. The producer that lags behind will not achieve success unless changes are made in good time.

It is therefore important that an in-depth evaluation is made regarding the whole production cycle – cultivation; pest, weed and disease control; pre-harvesting processes; harvesting methods; sorting or grading; packaging; cost and profitability – either for cutting costs or to please consumers. Market information is a crucial source of information.

The question that needs to be asked is - how can we improve on what we did? What steps can be taken to produce a better product?

The answers to these questions will ensure that production is sustainable and that everyone involved in the production process will benefit from it!