ABSTRACT
Seed granulation is a coating technique, which turns a raw material mixture of sand, loam, water, seeds, and fertilizers into seedballs. It enhances the seedling establishment and early growth of crops, like pearl millet, in nutrient-poor soil. Mechanization is highly required, as large-scale production poses challenges to local farmers due to time constraints and labor demand. The prototype of a drum granulator for seeds, also known as a seedball machine, essentially consists of a metal frame and a drum. The seedballs are formed by a rotational motion of the drum. The construction and operation of the machine were designed to be simple. In this study, the combined effect of different factors, such as substrate composition, rotational speed and residence time was taken into account. This study revealed that the amount of loam and the rotational speed of the drum appeared to be the most influencing factors on seedball production and quality. The machine had a production capacity of seedballs ten times higher than manual production. The machine-made seedballs were also of high quality, exceeding 98% germination rate under greenhouse conditions. Besides pearl millet, the machine can be potentially used for other small-sized seeds, such as cotton or sesame.
ABSTRACT
Plantain flour (PLF) and soy flour (SF) were used to substitute wheat flour (10% and 20% w/w) in composite bread. Physicochemical, phytochemical, and sensory properties were investigated. Partial substitution by PLF significantly increased (p < .05) starch, amylose, ascorbic acid, and potassium content in bread samples. In contrast, a significant improvement (p < .05) in protein, fat, amylopectin, and calcium content was observed with SF substitution. Composite bread with PLF and SF together lowered the hydrolysis index (HI) and glycemic index (GI) as compared with whole wheat flour. The molar phytate to minerals (iron, zinc, and calcium) ratio in all composite loaves was lower than reported critical values, except for phytate to iron. Significant differences (p < .05) were found in color, specific volume, and texture characteristics of loaves made from partial substitution with PLF and SF. Sensory evaluation revealed that bread with 10% PLF exhibited better scores for appearance and willingness to pay than the control. In contrast, SF negatively affected (p < .05) the appearance, texture, color, overall acceptance, and willingness to pay. The trade-off analysis indicated that PLF can be utilized to produce bread that meets consumers' demands, while incorporating SF as an alternative high-nutrient density bread will be beneficial to health.
ABSTRACT
Cassava is grown because of its starchy roots, but the leaves being rich in protein are mostly underutilized. For protein recovery, mechanical juice extraction from cassava leaves and the extraction process was evaluated using computational fluid dynamics (CFD) simulation. The influence of input variables such as nozzle diameter and rotational speed of the screw was investigated in relation to process efficiency. The highest green juice extraction yield (81.0%) from cassava leaves and dry matter of press cake (61.3%) were achieved by using 4 mm nozzle diameter and 18 rpm screw speed. The protein content of the cassava leaves, press cake, juice sediment, and juice supernatant was found to be 31.5%, 27.7%, 26.2%, and 12.4%, respectively. The crude protein, cellulose, hemicellulose, lignin, and total phenolic content mainly accumulated in the press cake. The screw pressing concentrated the amino acids in the press cake and the juice sediment.
ABSTRACT
Solar drying is one of the most efficient and cost-effective, renewable, and sustainable technologies to conserve agricultural products in Asian and sub-Saharan African (SSA) countries. This review paper presents the different types of solar dryers that are widely used in Africa and Asia. In addition, the pre-eminent effects of their use on product quality, as well as their economic, environmental, and social impacts, are highlighted. Since financial, external, and structural factors play a key role in the adoption and scaling of solar dryers, this paper also discusses the impact of these factors on the effectiveness of solar drying technologies in selected Asian and SSA countries.
