Brief on the technology


An improved parboiling technology called grain quality-enhancer, energy efficient and durable material (GEM) parboiling technology combines the use of a uniform steam parboiler and an improved parboiling stove. When the quantity of paddy to be parboiled is more than 50kg per session, other components (paddy soaking tank, laborsaving devices and improved drying surface) are required. The GEM parboiling technology is not only about the equipment but also the process.


GEM Parboiling installation in Bukan-Sidi-Lafia Rice Innovation Platform, Nassarawa State, Nigeria (AfricaRice, 2016, Ndindeng et al. 2015)



The parboiler consists of a stainless steel mesh basket that sits on a support in a stainless steel tank. During steaming, boiling water in the tank produces vapor that steams the paddy in the mesh basket. The tank is closed by a tight fitting lid that reduces heat loss but the system is not pressurized. The paddy soaking tank is made from stainless tank with a false bottom, a water discharge point and a paddy discharge point.

The stove is an improved rocket stove made of baked clay bricks with special ventilation. The stoves protect the user from heat and smoke exposure.

The laborsaving devices are either a rotational hoist or a chain hoist system for paddy weights less than 50 kg or paddy weights between 50—100kg respectively.

The improved drying surfaces are cemented floors that have a 5% slope and raised 50cm from the ground. These surfaces have walkways that prevent users from walking directly on the drying surfaces to reduce contamination.

The GEM parboiling technology can be tailor for small (20-300kg), medium (300-1000kg) and large (1000-3000kg) scale processors. The cost of the technology will depend on the components and the scale of operation.

Suitable ecologies

The GEM parboiling technology is suitable for both rainfed and irrigated ecologies but it’s profitability is higher in irrigated ecology due to reduced brown to black spots on paddy.

Gender Sensitiveness

The GEM parboiling technology was co-developed with women from the Glazoue Innovation Platform (IP) in Benin. The technology was developed to reduce drudgery, the risk of heat burns and exposure to smoke to the operator who are mostly women.

Changes and or impact

Women parboilers that use the GEM technology make an extra 200 USD on every ton of rice parboiled compared to parboilers using the traditional system.

The GEM parboiling technology has higher output rate of up to 25 tons of milled rice per month of high quality (lighter and uniform color, absence of heat-damaged grains and impurities, low levels of broken fractions).

The GEM parboiling technology reduces expenditure on firewood from 1.83 to 0.64 USD per 100kg of paddy parboiled.

The GEM parboiling technology reduces the steaming time from about 60-90 min to 20-25 min per 100kg of paddy.

Women who use the GEM parboiling technology indicate that they do not suffer from heat burns and other sickness especially those related to smoke exposure and poor hygiene and face less difficulty in lifting loads.

The internal rate of return (IRR) of the GEM parboiling technology is 70% compared to 14% for the traditional technology.