Thursday, May 19, 2016

Going beyond boiled rice

Traditionally, rice is eaten around the world as a basic starchy (carbohydrate) staple, perhaps with the major exception of rice noodles in eastern Asia. However, there are good reasons for doing more with rice than simply boiling it.

The first of these is to add value to lower grades of rice. Local rice has historically been unpopular in many parts of Africa because of its quality — it is often perceived as heterogeneous, impure and unclean compared with clean, white, uniform imported rice, and consequently sold at lower prices on local markets.

One particular issue has been the quality of milling, which often leaves local rice as a mixture of sizes of broken grains. There are a few cultures that actually prefer broken grains — notably Senegal (and even here, it is broken rice of uniform granulation that is preferred) — but, for the most part, broken rice is considered inferior to unbroken rice and therefore of lower value.

With many countries having increased their rice production over a number of years, some markets have experienced a glut of local ‘inferior’ rice, which has not met with universal acceptance. Rather than let this rice go to waste, AfricaRice has in the past developed (or sought out) recipes to make use of it, thereby adding value to it.

The simplest route was that followed historically by those promoting other starchy staples such as potato: grind it up to make flour. Rice flour (cheaper in many parts of the tropics than imported wheat flour) can then be used as a substitute for wheat flour in typical flour-based foods, such as bread and cakes.

Rice flour is a particularly good substitute for wheat flour for those who are gluten-intolerant. It is also used as a thickening agent in recipes that are refrigerated or frozen, since it inhibits liquid separation.

“Over the past year or two, we have decided that this is not enough!” declares AfricaRice grain-quality specialist John Manful. “We are now looking at adding nutritional value to rice.” This is being done via several routes with a range of partners.

 AfricaRice has been working with Centre de coopération internationale en recherche agronomique pour le développement (CIRAD) to ‘re-engineer’ a rice-based steamed product, ablo, using lower-grade rice grains. The re-engineering comprises standardizing processing operations, recommending best practices and identifying local varieties best suited for ablo production.   

A raw white rice grain is primarily carbohydrate (about 80%), water (c.12%) and protein (c.7%); it is not rich in any macro- or micronutrients or vitamins. As such it does not have a particularly balanced nutritional value.

“One approach is to incorporate more nutritious food sources into rice flour,” says Manful, “such as grain legumes for protein and fruits for minerals and vitamins. In particular, we have made flour rich in minerals and vitamins from dried safou [a forest fruit of West and Central Africa popular in Cameroon], which we have then mixed with rice flour.”

The composite flour has been used to make biscuits (cookies) and pastries in Cameroon and Nigeria, where the field-tested products are ready for commercialization.

“Another approach is to fortify rice directly with a range of minerals and vitamins,” says Manful. AfricaRice’s partners in this venture are Louisiana State University (USA) and the WrightGroup (Crowley, LA, USA). The Wright Group has a history of rice fortification dating back to 1894.

The technique that is being trialed for Africa is a ‘rinse-resistant technology’: in excess of 80% of the fortification coating remains on the rice grains during washing and cooking — this resistance has been and continues to be verified by Louisiana State University.

With the technology available, the big question was whether the fortified rice would be acceptable to consumers. “We blended fortified rice with ‘regular’ rice, and then made biscuits, boiled rice and porridge [a rice version of oatmeal], which we presented to taste panels in Benin and Ghana,” Manful explains.

Could they detect the fortification? Would there be a negative reaction to it? “At very high levels of fortification, some of the taste-testers could tell that the fortified rice was different from ‘regular’ rice,” says Manful. “Remarkably, however, they actually preferred the taste of the fortified rice!” Thus, a potentially major hurdle was overcome: there was no adverse reaction from the consumers to this fortification of rice.

“The beauty of this technique is that, if we have a rice-eating population that has a diet deficient in some mineral or vitamin, or combination of those, then we can make a specific fortification formula with the deficient nutritional elements and coat their rice with it,” says Manful. This will ensure that populations get exactly what they need — no more, no less. 

“There is an additional benefit to this kind of nutritional fortification,” says Manful. “It is an additive; we are not manipulating the genetics of the rice itself.” For whatever reason, there is still strong opposition in many parts of the world to genetically modified (GM) food, which limits the potential scope of advancements such as ‘Golden Rice’ (rice genetically fortified with vitamin A). “The anti-GM lobby has no argument about the kind of fortification we are testing,” says Manful. 

Moreover, the fortification through coating can be applied to any rice. So a target community can continue to eat its preferred varieties, rather than having to adopt new varieties to meet its nutritional requirements. 

AfricaRice is now working with the Wright Group and Louisiana State University to see how the technology can be adopted by private-sector small and medium-sized enterprises in Africa to make it commercial.

The fortification of rice-based products is particularly targeted at children and pregnant women, who are perhaps the most nutritionally sensitive elements of any society. Louisiana State University is leading the validation of the positive effects of consumption of fortified rice on malnourished children.

AfricaRice is also targeting digestive problems, particularly type 2 diabetes and gluten-related disorders. Many readers may not be aware that these two disorders are increasing within the populations of developing countries, just as they are in developed countries. 

AfricaRice is working with the University of Milan to develop rice pastas. Who better to work with on pasta than an Italian university? “We are testing 100% rice pasta,” explains Manful, “which has advantages over both wheat pasta and boiled rice.”

Rice is gluten-free, which means that it is a good starchy staple for those with gluten-related disorders. It has also been shown that rice pasta is more slowly digested than boiled rice, which aids in the management of type 2 diabetes. “We have developed many rice-pasta products,” says Manful, “for which we are currently conducting consumer tests.”

Parboiling (boiling or steaming paddy prior to milling) is becoming increasingly popular as a means of improving the quality and milling recovery of local rice in several parts of Africa. A secondary effect of parboiling is that it slows the digestion rate of rice.

Having introduced improved parboiling techniques to several countries in the region (most recently through the rice sector development hubs), AfricaRice is now working with McGill University (Canada), the University of Milan and partners from national agricultural research systems in Cameroon, Ghana and Nigeria to improve the parboiling process to optimize the digestive rate of rice for those with type 2 diabetes.

“All of this work is being carried out under the broader framework of the Africa-wide Rice Processing and Value Addition Task Force,” says Manful, “and validated technologies from the research are shared with all partners within the task force.” 

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