**1. Introduction**

Maize is among the three critical cereal grains in the world, others being wheat and rice [1]. Maize was first identified in central Mexico 7000 years ago from a wild grass and Indigenous Americans converted it into food [2]. This cereal grain contains starch (60–80%), protein (8–12%), fat (3–5%), and minerals (1–2%) [3, 4]. It is grown worldwide, with Unites States, China, and Brazil as the top three maizeproducing countries with a combined production of approximately 563 of the 717 million tons/year [2]. Maize contains nutrients for both humans and animals but it

is also used for production of starch, oil and protein, alcoholic beverages, food sweeteners, and biofuels [5]. The significance of maize as a staple food in low developing countries can be compared to that of wheat in Asia. It is mostly consumed in Eastern, Western and Southern Africa in different forms such as *kenkey* in Ghana, *Ogi* in Nigeria, stiff porridge (*nsima*) in Malawi, maize meal (*ugali*) in Kenya [6]**,** and posho and porridge in Uganda. In Sub Saharan Africa (SSA), over 208 million people bank on maize as a food source and being economically empowered [7]. Out of the 22 countries in the world where maize is mostly consumed, 16 of them are found in Africa [7]. This makes maize a very important cereal in Africa. Despite its importance, the losses of maize after harvest have decreased its availability among the poor people in Africa. In Uganda, for example, maize postharvest losses are about 30% [1] which has escalated hunger especially among the poor in the villages.

Maize processing include harvesting, dehusking, drying, shelling, storing, and milling. Compared to other operations, shelling still stand out as the most challenging operation that requires more work to improve it [8]. For the maize farmers to fully enjoy the financial benefits from their maize, appropriate technology that suits their needs is a requirement. In this regard, motorized immobile maize shellers have been fabricated locally to enhance the shelling operation. However, their performance has not elated the farmers. The unsatisfactory performance is a result of these shellers being fabricated by local artisans with finite understanding of the maize grain characteristics and operation factors to optimize maize shelling [1]. In addition, farmers in low developing countries have a deficiency of power to operate the motorized maize shellers available. It has been reported that transportation of these immobile maize shellers with the engines to run them from place to place is a big problem to sheller service providers; often requiring an additional carrier to move shellers to the farmers' field. The shelling service providers hence ask for an extra cost, which is usually passed on to farmers. These shellers also require extra time and energy to arrange the maize shelling environment at the farm level [9].

To consider the shelling power and sheller transportation problems, low cost motorized mobile maize shelling technologies have been developed as a result of modifying the available motorized immobile maize shellers. Some motorized mobile maize shellers were fabricated in 2012 by industrious fabricator Munyegera Agro-Machinery in Eastern part of Uganda [10]. Later, the multipurpose vehicle mobile maize shelling technology was introduced [1]. In Bangladesh, a two-wheel tractor mounted mobile sheller for small scale farmers was also introduced [9]. In this book chapter, maize shelling operation in low developing countries has been described with focus on encouraging a paradigm shift from the motorized immobile maize shellers to mobile maize shellers as a solution to the maize shelling constraints in these countries.

### **2. Maize shelling as a postharvest operation**

Maize shelling as a postharvest operation is the removal of maize seeds from the cob [11]. This operation can be carried out either in the field or at the storage facility. Maize shelling is therefore an important step towards the processing of maize to various finished products like flour and maize bran.

### **2.1 Maize shelling in developed countries**

In developed countries like Europe, North America, and China, maize shelling operation is done using combine harvesters [12]. Combine harvesters (**Figure 1**)

*Improving Maize Shelling Operation Using Motorized Mobile Shellers… DOI: http://dx.doi.org/10.5772/intechopen.101039*

**Figure 1.** *Different components of a combine harvester [13].*

simultaneously perform operations of ear picking, threshing, separation, and cleaning on the mature maize plants in the field. The purpose of this mechanized maize harvesting technology is to replace manual labor to harvest maize from fields in time with minimum loss while maintain high quality standards [14]. Some of the advantages of mechanized maize shelling include: reduced drudgery, enhanced productivity, time consciousness of agricultural operation, and availing labor for other agricultural operations. Combine harvester designers are working towards the quality of the process automatic controls and protecting the environment [15].

### **2.2 Maize shelling in low developing countries**

Maize shelling in low developing countries is still a challenge to its value addition as it is tiresome and requires a number of labor hours [11]. A major issue for maize value chain is that good quality maize is difficult to find among farmers. Many times, buyers are ready to pay a high price for maize grains from farmers with good quality maize. However, good quality maize is often unavailable due to poor postharvest handling. The impacts of quality at postharvest level can be attributed to poor drying and storage methods among other factors. For example, maize drying on the bare ground, and storage in dump places and aflatoxin growth [10]. Beside drying and poor storage, maize post-harvest losses are also due to use of rudimentary tools like tapered cylindrical metallic shelling device [16].

Maize shelling methods can be categorized as traditional maize shilling, manual maize shelling, and motorized maize shelling based on the technology used.

### *2.2.1 Tradition maize shelling*

Maize is shelled traditionally by hand (**Figure 2**). Here, the grains are detached from the cob by pressing them with the thumb [2]. The technique produces unbroken kernels but the process is tedious. A few kilograms can be shelled in an hour, with damages left on shellers' fingers. Another simple and common method of traditional maize shelling is to rub two maize cobs against each other in order to

### **Figure 2.** *Maize shelling by hand [16].*

detach the maize kernels [17]. However, these traditional methods of shelling are, not efficient, consume a lot of time, and require a lot of energy with very low productivity since farmers can shell only a few kilograms/hour.
