**Abstract**

Paddy production in African is increasing at a significantly impressive rate due to increased public and private sector investment, the introduction of high yielding varieties and improved production practices. But about 40% or more of this quantity does not reach the table of consumers largely due to post-harvest losses. These losses are subdivided into physical grain loss (PGL) and grain quality loss (GQL). Efforts towards reducing these losses through valorisation of low quality rice and processing by-products has received attention over the last few years. Innovative development and out scaling of simple, cost effective, adoptable and well-defined practical technology to convert low grade milled rice to nutrient dense value-added products that could be used for family meals or weaning purposes and utilization of rice husk for energy is the new way to go. This paper reviews major advance made especially by the Africa-Wide Taskforce on rice processing and value addition and its partners in developing strategies for minimizing postharvest loss in Africa through the development of technologies for utilization of broken rice fractions and rice husk to reduce postharvest losses. Major challenges mitigating the adoption of this technologies and possible opportunities in the rice postharvest value chain that can attract investment for the improvement of rice production and reduction in rice postharvest losses are also outlined. This synthesis we believe will help in providing future direction for research and support for sustainable rice postharvest system in Africa.

**Keywords:** rice, Africa, postharvest losses, broken rice value addition, husk gasification, innovation

## **1. Introduction**

Rice (*Oryza sativa* L.) is one of the most important crop in the world in terms of total developing world production (480 x 106 tonnes of rough rice in 2012) and the number of consumers (3.5 billion) dependent on it as their staple food and is cultivated in over 100 countries in every continent (except Antarctica), from 53<sup>o</sup> N to 40o S and from the sea level to an altitude of 3 kilometres high [1]. In 2019, the total world rice production amounted to approximately 738.75 million metric tons

(MMT) from total harvested area of approximately 162.71 million ha, making rice the world's third most-produced cereal crop after maize (1.12 billion metric tons) and wheat (731.45 MMT) [2]. On the African continent, especially in sub-Saharan Africa (SSA), rice has become a staple food crop and constitutes major part of the human diet [3]. Over the last three decades, African countries has experienced a consistent increase in rice production and consumption demand making rice the fastest growing staple food especially among low income earners [4]. In countries such Tanzania, Niger and Nigeria transformational changes in the production practices and shift of consumer preference from other coarse grain such as corn, sorghum and millet towards rice is particularly glaring and fuelling increased local production and consumption demand. Available statistics indicated that Africa produce an estimated 20.5 million tonnes of paddy rice annually [5], and West Africa is the continent's rice powerhouse, producing about 66% of the total paddy in Africa, mostly by smallholder farmers [4].

The growth in rice production, processing and consumption in many Africa countries has been shown to have direct correlation with growing income, rapid urbanization, population growth, and change in the occupational structure of African families. It is believed that as more and more women and young girls in Africa join the workforce, and more men live and work in urban area, there is a shift toward food that is more convenient and cooks fast such as rice. Although the per capita consumption of rice is declining in many parts of Asia, in Africa, especially the SSA region, the demand for rice is increasing and at a faster rate than in any part of the world [6]. However, rice production in Africa has not kept pace with the increasing demand, resulting in huge volume of rice imported to fill the gap at a significantly high cost to Africa external reserves. Rice farmers in Africa, especially in Nigeria, Niger and Tanzania, have responded to the increasing demand for rice, as reflected in upward trends in total production in recent years [7]. But, when compared with population increases, the rice production trends are much less impressive and many of the countries are becoming increasingly dependent on rice imports, fuelled by growing production-to-consumption gaps [8].

Geographically, according to International Rice Research Institute (IRRI), Africa has the highest reserves of untapped natural resources for food production globally, especially water and land (130 million ha of inland valley) which are essential for rice production [5]. In spite of these sizeable land and favourable agro-ecological conditions, the Food and Agriculture Organization [7] and The World Bank, [9] states that significant number of population are undernourished while poverty and unemployment levels in country such as Nigeria is significantly high (69%). Added to the high level of unemployment, food insecurity and under nutrition, there is huge food losses and waste along the entire food value chain. It has therefore become imperative to make concerted efforts to reduce losses especially postharvest losses to improve food and nutrition security in Africa [10]. Huge volume of rice produced in Africa for instant like in most developing countries does not reach the table of the final consumers due to significant post-harvest losses in terms of physical grain loss (PGL) and grain quality loss (GQL) [11].

Research for development (R4D) in Africa have developed technologies and innovations and made recommendations for increasing rice productivity through the use of high yielding varieties, expansion of area under cultivation and reducing postharvest losses through good production practices and adoption of improved technologies [10, 11]. However, in most African countries, where tropical weather and poorly developed infrastructure contribute to the problem of food loss, wastage can regularly be as high as 40–50% and has been one of the key encumbrances to farmers' income and sustainable food security in this region [12, 13]. Postharvest losses have therefore contributed significantly to African's inability to attain

**209**

*Advances in Rice Postharvest Loss Reduction Strategies in Africa through Low Grade Broken Rice…*

self-sufficiency in local food production and also a huge drain to local production and food security, as colossal quantities of food, including rice are lost, year after year [13]. Globally, Gustavsson *et al*., [14] noted that about 1.3 billion tons of food are wasted or lost annually, while in the local context such as Nigeria, the country's agricultural productivity has been generally low, mostly due to post harvest losses of farm produce (20% for grains such as rice and over 40% for fruits and vegetables), and attributed these to poor post-harvest handling, inadequate agro-processing

The adoption of good agronomic practices, favourable government policies and shift in consumer preference from other staple coarse grains toward rice have fuelled increased production and yield per hectare of rice across Africa. However, postharvest losses that have been relatively small in absolute terms have increased proportionally with increased yield per ha. Therefore, integrated management of postharvest operations such as threshing, cleaning, drying, parboiling, milling, grading and branding and storage have now been adopted in many rice producing

Ndindeng *et al*, [11] observed that resolving the critical issues along the rice value chain in many SSA countries is also impeded by the lack of a simple, adoptable and well- defined practical methodology on how to estimate PGL and GQL after harvest. This makes it impossible to have credible data during the various operations along the rice value-chain. Secondly, there is also wide quality gap between imported milled rice and domestically processed rice. The locally processed rice in Africa including Nigeria tend to be of poor quality due to high level of impurities (stones, weed seeds, sand and insect residues), high level of broken fractions, variability in grain size and colour and off-flavour perceived when cooked. However, many cost effective and efficient postharvest handling machines and practices developed and recommended by R4D organizations are not available for farmers, probably due to poor extension and funding challenges. In postharvest operation such as parboiling, the use of rudimentary technologies has resulted in high losses estimated at 15–20% with high energy and water demand which contributes to the final cost of the final product and environmentally unsustainable practices because of dependent of wood fuel [10]. They recommended the valorisation of rice processing by products to enhance income for the rice value chain actors and also

Broken rice fractions, bran and husk are major by-products of rice processing operations. They account for about 25–50% by weight of milled rice depending on variety and technology of milling. In many rice producing communities in Africa, rice processing by-products such as husk and bran are generally dispose and dumped as hips of wastes in many rice processing sites with little or no environmentally friendly ways of disposal. This has resulted in dusk related health challenges for people living nearby and methane emission during its natural decomposition [15]. But research in many parts of the world including Africa has indicated that rice husk if properly harnessed can serve as good raw materials for fuel [16, 17] and low grade broken fractions could be used for the production of other value added products [10] that may increase farmer's income, safe guide the environment and improve food and nutrition security. Broken rice fractions can be converted to high quality flour and used for the production of value added products that can enhance nutrition and food security and livelihood of smallholder farmers and profitability of small-scale food processing industries [18]. It can also employ huge number of youths and women and serve as sources of employment and reduce restiveness. This chapter will cover selected innovative techniques and technology advancement made especially by the Africa-Wide Taskforce on Rice Processing and Value Addition and its partners in developing strategies for minimizing postharvest loss

*DOI: http://dx.doi.org/10.5772/intechopen.94273*

development among other critical factors.

clusters to reduce losses at each stage of the chain [13].

improve food security and sustainable environment.

#### *Advances in Rice Postharvest Loss Reduction Strategies in Africa through Low Grade Broken Rice… DOI: http://dx.doi.org/10.5772/intechopen.94273*

self-sufficiency in local food production and also a huge drain to local production and food security, as colossal quantities of food, including rice are lost, year after year [13]. Globally, Gustavsson *et al*., [14] noted that about 1.3 billion tons of food are wasted or lost annually, while in the local context such as Nigeria, the country's agricultural productivity has been generally low, mostly due to post harvest losses of farm produce (20% for grains such as rice and over 40% for fruits and vegetables), and attributed these to poor post-harvest handling, inadequate agro-processing development among other critical factors.

The adoption of good agronomic practices, favourable government policies and shift in consumer preference from other staple coarse grains toward rice have fuelled increased production and yield per hectare of rice across Africa. However, postharvest losses that have been relatively small in absolute terms have increased proportionally with increased yield per ha. Therefore, integrated management of postharvest operations such as threshing, cleaning, drying, parboiling, milling, grading and branding and storage have now been adopted in many rice producing clusters to reduce losses at each stage of the chain [13].

Ndindeng *et al*, [11] observed that resolving the critical issues along the rice value chain in many SSA countries is also impeded by the lack of a simple, adoptable and well- defined practical methodology on how to estimate PGL and GQL after harvest. This makes it impossible to have credible data during the various operations along the rice value-chain. Secondly, there is also wide quality gap between imported milled rice and domestically processed rice. The locally processed rice in Africa including Nigeria tend to be of poor quality due to high level of impurities (stones, weed seeds, sand and insect residues), high level of broken fractions, variability in grain size and colour and off-flavour perceived when cooked. However, many cost effective and efficient postharvest handling machines and practices developed and recommended by R4D organizations are not available for farmers, probably due to poor extension and funding challenges. In postharvest operation such as parboiling, the use of rudimentary technologies has resulted in high losses estimated at 15–20% with high energy and water demand which contributes to the final cost of the final product and environmentally unsustainable practices because of dependent of wood fuel [10]. They recommended the valorisation of rice processing by products to enhance income for the rice value chain actors and also improve food security and sustainable environment.

Broken rice fractions, bran and husk are major by-products of rice processing operations. They account for about 25–50% by weight of milled rice depending on variety and technology of milling. In many rice producing communities in Africa, rice processing by-products such as husk and bran are generally dispose and dumped as hips of wastes in many rice processing sites with little or no environmentally friendly ways of disposal. This has resulted in dusk related health challenges for people living nearby and methane emission during its natural decomposition [15]. But research in many parts of the world including Africa has indicated that rice husk if properly harnessed can serve as good raw materials for fuel [16, 17] and low grade broken fractions could be used for the production of other value added products [10] that may increase farmer's income, safe guide the environment and improve food and nutrition security. Broken rice fractions can be converted to high quality flour and used for the production of value added products that can enhance nutrition and food security and livelihood of smallholder farmers and profitability of small-scale food processing industries [18]. It can also employ huge number of youths and women and serve as sources of employment and reduce restiveness.

This chapter will cover selected innovative techniques and technology advancement made especially by the Africa-Wide Taskforce on Rice Processing and Value Addition and its partners in developing strategies for minimizing postharvest loss

*Recent Advances in Rice Research*

mostly by smallholder farmers [4].

(MMT) from total harvested area of approximately 162.71 million ha, making rice the world's third most-produced cereal crop after maize (1.12 billion metric tons) and wheat (731.45 MMT) [2]. On the African continent, especially in sub-Saharan Africa (SSA), rice has become a staple food crop and constitutes major part of the human diet [3]. Over the last three decades, African countries has experienced a consistent increase in rice production and consumption demand making rice the fastest growing staple food especially among low income earners [4]. In countries such Tanzania, Niger and Nigeria transformational changes in the production practices and shift of consumer preference from other coarse grain such as corn, sorghum and millet towards rice is particularly glaring and fuelling increased local production and consumption demand. Available statistics indicated that Africa produce an estimated 20.5 million tonnes of paddy rice annually [5], and West Africa is the continent's rice powerhouse, producing about 66% of the total paddy in Africa,

The growth in rice production, processing and consumption in many Africa countries has been shown to have direct correlation with growing income, rapid urbanization, population growth, and change in the occupational structure of African families. It is believed that as more and more women and young girls in Africa join the workforce, and more men live and work in urban area, there is a shift toward food that is more convenient and cooks fast such as rice. Although the per capita consumption of rice is declining in many parts of Asia, in Africa, especially the SSA region, the demand for rice is increasing and at a faster rate than in any part of the world [6]. However, rice production in Africa has not kept pace with the increasing demand, resulting in huge volume of rice imported to fill the gap at a significantly high cost to Africa external reserves. Rice farmers in Africa, especially in Nigeria, Niger and Tanzania, have responded to the increasing demand for rice, as reflected in upward trends in total production in recent years [7]. But, when compared with population increases, the rice production trends are much less impressive and many of the countries are becoming increasingly dependent on rice

imports, fuelled by growing production-to-consumption gaps [8].

cal grain loss (PGL) and grain quality loss (GQL) [11].

Geographically, according to International Rice Research Institute (IRRI), Africa has the highest reserves of untapped natural resources for food production globally, especially water and land (130 million ha of inland valley) which are essential for rice production [5]. In spite of these sizeable land and favourable agro-ecological conditions, the Food and Agriculture Organization [7] and The World Bank, [9] states that significant number of population are undernourished while poverty and unemployment levels in country such as Nigeria is significantly high (69%). Added to the high level of unemployment, food insecurity and under nutrition, there is huge food losses and waste along the entire food value chain. It has therefore become imperative to make concerted efforts to reduce losses especially postharvest losses to improve food and nutrition security in Africa [10]. Huge volume of rice produced in Africa for instant like in most developing countries does not reach the table of the final consumers due to significant post-harvest losses in terms of physi-

Research for development (R4D) in Africa have developed technologies and innovations and made recommendations for increasing rice productivity through the use of high yielding varieties, expansion of area under cultivation and reducing postharvest losses through good production practices and adoption of improved technologies [10, 11]. However, in most African countries, where tropical weather and poorly developed infrastructure contribute to the problem of food loss, wastage can regularly be as high as 40–50% and has been one of the key encumbrances to farmers' income and sustainable food security in this region [12, 13]. Postharvest losses have therefore contributed significantly to African's inability to attain

**208**

in Africa through the development of technologies for utilization of broken rice fractions and rice husk to reduce rice postharvest losses in Africa. Major challenges mitigating the adoption of this technologies and possible opportunities in the rice postharvest value chain that can attract investment for the improvement of rice production and reduction in rice postharvest losses are also outlined. This synthesis we believe will help in providing future direction for research and support for sustainable rice postharvest system in Africa.
