Acacia, that shrub or tree which predominantly grows in arid and semi-arid areas on its own, and is largely found a nuisance by many, is gold.
The tree produces many products, including animal feeds and Gum Arabic, a much-sought product globally as it is used widely in the value addition industry.
Acacias are highly drought-resistant, therefore, thrive in harsh dry environments due to their tolerance to water scarcity.
Most acacia trees produce gum when under stress, with the highest yields experienced during the dry season.
The trees, being the main plantation in arid and semi-arid areas, have been found to enhance soil stabilisation and fertility through biological nitrogen fixation, thus contributing to environmental conservation.
Therefore, despite the harsh climatic conditions, acacia trees enhance crop production in the drylands.
When it comes to animal feeds, the acacia tree’s pods and leaves are used as fodder for camel and goats. Moreover, seeds from these trees are dried and conserved for human consumption.
But of the tree’s products, Gum Arabic, also known as acacia gum, is the most lucrative.
Gum Arabic is a substance secreted by the acacia tree consisting of the hardened sap that is pale to orange-brown and has a glassy fracture. The best grades of the gum are whole, round tears and orange-brown.
Mostly, Gum Arabic comes from two acacia tree varieties, namely Acacia senegal and Acacia seyal. In Kenya, however, it is mainly sourced from Acacia senegal that produces up to 90 per cent of the marketed Gum Arabic sold in the world.
The product is the “desert gold”, the only one of its own kind that is mined from trees. Its demand is constantly rising each day as new uses keep on emerging.
Research, however, has shown that low levels of income are generated by pastoralists through collection and subsequent sale of Gum Arabic in Kenya, despite the fact that it is the second most important source of income after livestock production in the drylands.
USES OF GUM ARABIC IN THE FOOD INDUSTRY
Besides its direct consumption, the gum is used in tens of food products as it has been approved by the Codex Alimentarius and the World Health Organisation as a food additive, labelled E414. In food products, it is used for various purposes:
1. Preservative in meat products:
Research by Egerton University shows Gum Arabic can be used as an extender in the making of beef hams.
The new technology involves utilising Gum Arabic (Acacia senegal var kerensis), which is readily available in the drylands by harnessing its water-binding capacity.
The technology was tested at the Castle Meat Products, Njoro and the end result was a juicy meat product with high sensory attributes.
The ham is prepared by marinating the raw meat with a curing solution containing the Gum Arabic. The marinated product is then allowed to imbibe the solution leading to a juicy final product.
The advantage with the technology is its ease of adaptability by small and medium enterprises, with the final product providing the consumer with soluble fibre.
The research showed that an entrepreneur starting with 75kg of raw beef will end with a final product weighing 100kg.
2. Flavour encapsulation in beverages:
Gum Arabic is an ideal carrier of flavour during encapsulation in the making of beverages because of its natural emulsifying and surface-active properties and good retention of volatile flavour components.
Being an emulsifier, Gum Arabic from Acacia senegal at an optimal level of 0.6 per cent was found to be a better emulsifier in low fat yoghurt. In soft drinks like sodas, Gum Arabic enhances mouthfeel, emulsifies and stabilises flavours.
In beer and wine making, it helps to improve foam stabilisation, colour and clarity.
Gum Arabic is used in high sugar, reduced sugar and no-sugar confectioneries to prevent sugar crystallisation, as the main binding agent, and a source of fibre.
In caramels, it improves chewiness, fat distribution, texture and achieves increased resistance to oxidation.
In chewing gums, its use results in softening of the chew, retention of water and flavour and improved texture and body while in snacks and baked products, it is used to improve flavour adhesion, texture and glaze.
4. Pharmaceutical and nutraceuticals:
Due to its high solubility, low viscosity and high soluble dietary fibre content, Gum Arabic finds use in nutritional beverages and weight-loss products.
It has about 85 per cent soluble fibre and is used typically for healing wounds and also helps to inhibit the growth of periodontal bacteria and the early deposition of plaque on teeth.
USES IN OTHER INDUSRIES
Gum Arabic is also used in making ink, lithographic plates, special papers, fabrics, and as an anti-corrosive coating for metals as well as in the manufacture of matches and ceramic pottery.
The gum is also applicable in adhesives, water paints and pastels, fireworks, cartridge powder, pesticide and insecticide sprays, concrete and in detergents.
Prospects of farming acacia
Commercial farming of acacia trees for the harvesting of Gum Arabic and animal feeds is a viable business.
Kenya is endowed with gum-yielding trees but exports only small amounts of gum. This forms income for most families living in the range lands.
Most of the collected gum is exported, minimal amounts are utilised locally as food and in value addition. Up to 2013, Kenya was only able to exploit about 38 per cent of its Gum Arabic production potential which is estimated at 8,000 metric tonnes per year.
Across the region, Sudan and Ethiopia lead in production of the produce respectively, with Kenya coming in third.
Besides the naturally growing trees, it is possible to plant and manage acacia trees.
These trees are highly suitable for agroforestry systems, and can be grown in combination with other plants such as watermelon, millet and forage grasses.
In Sudan, acacia is grown in ‘gum gardens’ for production of Gum Arabic as well as to conserve and enhance soil fertility.
High quality tree seeds and seedlings for cultivation can easily be obtained from the Kenya Forestry Research Institute.
Research shows 80 per cent of the country’s regions have trees that produce Gum Arabic.
Eight counties in Kenya including Garissa, Isiolo, Mandera, Marsabit, Moyale, Samburu, Turkana and Wajir have great potential for production of the gum.
Already, these areas have plenty of the naturally growing acacia trees whose exploitation for gum production is minimal.
Other uses of acacia trees
- The trees are also major sources of fuel for families residing in the drylands of Kenya.
- Dried branches are used as firewood while some families exploit it for charcoal production.
- This way, these families are able to earn some extra income from charcoal sales.
- Sustainable production of charcoal is possible if cultivating acacia trees can be practised in the drylands. This will ensure that trees are not just cut, but new ones are planted.
- Research into new uses of Gum Arabic are, therefore, important since success in such research will introduce new lines for consumption of the gum increasing the returns.
- This will eventually result in food security in arid and semi-arid lands.