Reducing Losses and Empowering Farmers Through Horticultural Science

Horticultural Science

Horticultural Science

 Reducing Post-Harvest Losses Of Fruit And Vegetables

  • Short course in post-harvest technology and physiology
  • Extending the shelf life of vegetable crops via alternative technologies: SmartFresh and MAP packaging.
  • Identify preferences of local consumers for apple appearance and taste.
  • Effect of canopy position on internal fruit quality and its affect on consumer acceptance of apples.
  • Evaluate mobile rapid cooler (MRC) to pre-cool small loads of vegetables and fruit in remote production areas

Area/s of Food Security (Access, Availability, Utilization) that project/s fall under:

Availability and Utilization: Fluctuating and erratic temperatures experienced during cold chain handling often lead to product losses due to the negative effects on shelf life, quality and nutritional value. This project will potentially provide the export and retail markets with post-harvest cold chain management practices and implementations which may act as buffers against the damaging effects of fluctuating temperatures. This may be achieved via the implementation of specialized packaging and the application of senescence inhibitors or utilization of equipment such as the MRC.

Mixed loads are currently used in most local retail stores and during fresh-product distribution due to a lack of cold storage facilities or inherently mixed transport causing major losses. This project could prevent physiological disorders, rapid loss of green colour or shelf-life reduction in current mixed load handling of ethylene producing and sensitive crops by using an ethylene inhibitor.

Vegetable export may be possible with the extension of storage life using above mentioned technologies which would open new markets to South African vegetables, since air freight is in many cases too costly.

Studies in the USA, Europe and Oceania have indicated the existence of consumer groups that differ in their preference for apple taste and appearance.  No comparable studies have been conducted in South Africa among local consumers.  Targeted marketing of preferred apple cultivars to specific consumer groupings may increase overall consumption of apples and thereby reduce wastage.

Fruit from the inside and outside of the tree canopy are exposed to extreme light environments.  These fruit are grouped together on the shelf, even though they may vary considerably in internal quality.  The wide variation in fruit quality on the shelf is a primary reason for consumer dissatisfaction with purchased apples.  Selective harvesting and marketing of apples and other fruit types from different canopy positions may increase uniformity in fruit internal quality on the shelve, thereby improving customer satisfaction with the produce, increasing consumption and decreasing fruit wastage.

Finally storage at higher temperatures may be possible with the use of an ethylene inhibitor thus leading to a reduction in electricity consumption and therefore cost.

Access: Allow vegetable and fruit production in areas with limiting cold storage facilities and aid new business developments in rural areas.

How does the Project fit in with the FSI Vision?

As the definition of food security describes: “Food security exists when all people, at all times, have physical, economic and social access to sufficient, safe and nutritious food to meet their dietary needs and food preferences for an active and healthy life” (FAO 2002).  Through this research we aim at contributing to the supply of sufficient and nutritious fruit and vegetables to all people and reduce current losses.

Goal/s of your Projects

To decrease wastage by:

  • Training of staff working in the cold chain and handling produce from the farm to markets and retail outlets
  • Improving existing postharvest practices within the export and retail cold chain and thereby increase food supply, quality and nutritional value of products;
  • To make fruit and vegetable production more accessible to areas without adequate cold storage facilities and allow for new business opportunities in rural areas lacking in these capital expensive resources;
  • To qualitatively decrease the carbon foot print of exported products by lowering the dependence on energy used during cooling requirements.
  • Determining consumer preference for apple appearance and taste, thus facilitating the targeted marketing of apple cultivars to different consumer groupings.  Knowledge of consumer preferences with regards to apple appearance and taste may also increase the efficiency of local apple breeding programmes.
  • Determining whether apples from different canopy positions differ in internal quality and whether this affects consumer preference for these fruit.  Also establish how internal quality can be best quantified and try and develop equipment to determine these quality traits non-destructively.

What will the Outcomes of the Project be?

Meeting the vision of the FSI

The ultimate goal of the project is to reduce post harvest losses of fruit and vegetables, thereby increasing availability of nutritious food and increasing food security.

The different areas of Food Security (Access, Availability, Utilization)

A strong contribution will be made toward availability and utilization of products in terms of decreasing product losses and increasing or ensuring product nutrition, respectively. Access, in terms of increasing fruit and vegetable production in areas with limiting cold storage facilities will benefit from this research as well.


Popular publication on consumer preference for apple appearance and taste in SA Fruit Journal – maybe also radio contribution.

Scientific publications in peer-reviewed journals on 1) the role of ethylene, 1-MCP and packaging used in retail and export markets on shelf life, quality and nutritional value of various vegetable products 2) consumer preference for apple appearance and taste, and 3) the effect of canopy light environment on deciduous fruit internal quality and consumer acceptance.

Community Impacts

The results from this research will provide storage, export, distribution and retail companies within the fresh vegetable industry with updated postharvest alternatives to reduce losses and increase product quality.  The MRC could be utilised by growers in remote areas and small farmers to improve to quality of the produce that reach the markets and reduce losses.

What is the duration of the study?
How many students and researchers are involved?

The study will take place over a two to three year period.  The research will be conducted by MScAgric students as well as a PhD student and post doc. Three supervisors/promoters will assist and guide the students.

Tarryn de Beer is studying towards a MScAgric in Horticultural Science on extending the shelf life of vegetable crops via alternative technologies: SmartFresh and MAP packaging effect. Her supervisors are Elke Crouch (HortSci), Dr Deirdre Holcroft () and Prof Karen Theron (HortSci).

Anreza van der Merwe will submit a dissertation for a PhD degree in Food Science on consumer preference for apple appearance and taste.  Her promoters are Dr Wiehann Steyn (HortSci), Nina Muller (Food science), Dr Iwan Labuschagne (apple breeder at ColorsFruit), and Prof Tormod Naes (mathematician at Nofima, Norway).  Frikkie Calitz (ARC statistician) is collaborating on the project.

Esnath Hamadziripi is studying towards a MScAgric in Horticultural Science on the effect of canopy position on fruit quality and consumer acceptance. Please see the PDF document below to learn more about this fascinating project.  Her supervisors are Dr Steyn, Prof Karen Theron (HortSci), Nina Muller (Food science) and Michael Schmeisser (ecophysiologt, HortSci).

Canopy Position and Fruit Qualitys


Dr Piebiep Goufo post doctoral fellow (currently not at SU yet).

What funding opportunities exist for your project?

We are hopeful that HortGrow (formerly DFPT), the company overseeing the research and development needs of the South African deciduous fruit industry, will partially fund the project.  This will leverage additional funding via the THRIP programme of DTI.  We will hopefully also expand the research to citrus and therefore attract funding from Citrus Research International.  In addition the post doc will hopefully attract funding from the Claude Leon Foundation.

Contact details

Supervisor(s): Prof Karen Theron (; Elke Crouch ( and
Dr Wiehann Steyn (

Future areas of research

The effect of SmartFresh in limiting product losses in mixed load transport and storage. To decrease the need for capital intensive separate storage, transport and cooling facilities needed for individual products of varying ethylene sensitivities. I.e. Allow smaller quantise of greater product variety to be stored and transported together on an export and retail level. Also establish how internal quality can be best quantified and try and develop equipment in collaboration with Faculty of Engineering to determine these quality traits non-destructively.

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