Prickly pear a crop for arid regions

The most challenging areas for agricultural development and job creation in South Africa are the arid and semi-arid Karoo and Northern Cape, where only cactus appears to flourish. But researchers from the University of the Free State have found that the prickly plant could make the desert bloom.

The scientists found that the fruit of the cactus was far more nutritious than first believed, that the entire plant was suitable for processing into high-value products, and that the cactus pear delivered a high-yield, environmentally friendly crop in arid and marginal areas.

Researchers from the university’s biotechnology and animal science departments, along with the Agricultural Research Council, joined forces with biologists from universities and agencies in South America, to investigate the commercial potential of the plant.

Dr Maryna de Wit and her team of biotechnologists found the cactus pear had similar food value in terms of vitamin C, iron, calcium, magnesium, anti-oxidants and fibre content to most deciduous fruits such as apples, pears and grapes.

They believe that drying the prickly pear or processing it into jams, syrups, juices and purée could make it available year-round for health-conscious consumers, instead of simply being a short season for the fresh fruit.

“We are still only touching the surface of the uses of this marvellous plant,” said De Wit. “It should seriously be considered as an alternative crop for arid regions.”

Meanwhile, Professor HO de Waal from the university’s department of animal, wildlife and grassland sciences, reported that the leaves of the cactus pear – the cladodes – are a valuable source of animal feed.

De Waal said his department had designed processing techniques to turn the cladodes into dry-season fodder for sheep that is highly nutritious.

The cladodes also yield a nutrient-rich flour that can be substituted for wheat flour suitable for human consumption and ideal for people with food allergies. The mucilage extracted from the leaf is also suitable as a nutritive thickener to replace gelatine in vegetarian food preparation, and can even be used as an emulsifier in mayonnaise.

“The animal feed that we have produced from the cactus pear is light, easy to store and transport and highly nutritious,” De Waal said. “This is a multi-purpose crop with a huge number of applications.”

He said his team had managed to bake breads and cakes using up to 25% cladode flour and taste tests could not tell the difference from wheat flour. Also, cactus pear seed oil is the most expensive and sought-after plant oil in the world, used in the cosmetic, pharmaceutical and food industries.

“Cactus processing is still limited in South Africa and we need to develop an agro-industry,” said Dr Herman Fouché of the Agricultural Research Council. “It’s an environmentally friendly and bio-degradable product. It is time this Cinderella was recognised as a high-yielding multi-use crop with a very efficient water use capacity.”