Improving post-harvest technologies will enhance food security and health, says Asgar Ali.

Asgar Ali

In the midst of a perpetual population boom and conscious awareness of the limited and diminishing resources such as land, fertilizers and water availability, how will governments, organizations and people respond? And how should they respond? 

Significant effort has been dedicated at increasing agricultural productivity. But is it time to focus more on protetcing these gains from post-harvest losses?

The ‘green revolution‘ was a force of change in the 1960s and 1970s, and it highlighted the effect of the tremendous amount of effort exerted in breeding higher yielding, pest-resistant plant varieties. But too much of this food is spoiled or wasted in the journey from field to plate.

Down the drain

FAO statistics show world food production in 2010 (the latest figures available at time of writing) as 2432 million tonnes of cereals and 1574 million tonnes of fruits and vegetables combined. It is undisputable that world food production is sufficient to feed the entire world population. So where does all the food go?

Although statistics on food losses are generalized, it has been repeatedly estimated that almost one third (PDF) of the global food produced for human consumption is wasted. These figures includes pests and pathogens in the field, but I want to focus on losses in handling and storage that result from deterioration between harvest and distribution at market.

Developed and developing countries encounter similar losses, albeit for different reasons. In developing countries these losses are mainly attributed to technical and financial limitations that leave fruits and vegetable susceptible to physical damage and decay. Tropical fruits face numerous challenges during transportation and storage such as chilling injury, rapid maturation at ambient temperatures, fungal infection under moist environments and so forth. These are all results of inefficiencies in the food delivery system.

Postharvest technologies have been utilised by both growers and distributers to extend the shelf life of fruits and vegetables. Such technologies include modified atmosphere packaging or edible coatings which delay ripening through interplay of gaseous exchange and controlled product respiration.

One of my key research topics at the University of Nottingham has been the application of edible coatings on tropical and sub-tropical fruits. Gum arabic, chitosan and propolis (all natural chemicals) applied as composite coatings have been shown to be effective in extending the shelf life of produce and inhibiting microbial growth. Watch a video about my research here

Fruit cocktail

Malaysia, a typical tropical country, is endowed with a wealth of exotic fruits. These fruits, such as papaya and mangosteen, boast a range of beneficial nutritional and medicinal properties due to their high antioxidant content. The nutritional importance of diverse diets in combating degenerative diseases has been repeatedly highlighted, and such exotic fruits can play an important role in such diets.

However, plantations of such fruits in Malaysia are often poorly organised with minimal technologies available for pre-harvest and post-harvest treatments. Consequently, losses are substantial, and occur at the early stages of food production; within Southeast Asia (PDF) these postharvest losses are estimated at 20-50% (PDF).

There is an urgent need to quantify postharvest losses and to diagnose the causes. It may take little investment to minimise some of these losses, for example by managing cold chain or prompt delivery of harvested produce, but I believe  it will be money well spent.

Minimising postharvest losses of perishable produce will offset some of the need to expand areas of production and will increase food availability. Technologies that are currently available – and those that are in development – can provide solutions to existing problems in postharvest handling, if applied at the appropriate stage in the food supply chain.

About Asgar Ali

Dr Asgar Ali is an Associate Professor and Director of Centre of Excellence for Post-harvest Biotechnology (CEPB) at The University of Nottingham Malaysia Campus (UNMC). He is an expert in postharvest biology and technology and currently focusing on develop novel technologies which aimed at reducing food losses, improving overall quality and food safety of horticultural produce. He is involved in many government and industrial research projects to develop novel edible coatings based on natural products such as gum arabic, chitosan and propolis to control pre- and postharvest diseases and provide foods free from synthetic fungicides and pesticides residues. He is also working on Cerafusion technology to control postharvest anthracnose of tropical fruits and vegetables, and also to maintain postharvest quality, phytochemicals and antioxidants during storage.

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