Development and performance evaluation of a mini horizontal flash dryer

Cassava (Manihot esculenta) is a major staple crop in Nigeria, as cassava itself and its products are found in the daily meals of Nigerians. Currently, cassava crop is undergoing a transition from a mere subsistent crop found on the field of peasants to a commercial crop that will be grown in large quantities in plantations. A flash dryer was designed, fabricated, assembled and tested following the standard procedures. The flash dryer is a mechanized way of drying cassava mash for mass production of cassava flour, for flour mills, confectionery and pharmaceutical industries. The traditional method of producing cassava flour, results to low product quality and quantity for industrial usage because the mode of drying is dependent on climatic conditions and susceptible to contamination. The equipment was tested using already prepared cassava mash dewatered to a moisture content of 40%. Twenty five samples of this prepared cassava mash at varied temperatures of 70°C, 80°C, 90°C, 100°C and 110°C were subjected to different air velocities of 5 m/s, 10 m/s, 15 m/s, 20 m/s and 25 m/s. The equipment was fed at the rate of 60 kg/h. Air velocities of 5 m/s and 10 m/s were too low to convey the cassava mash and not all the material fed into the dryer went through. Air velocities of 20 m/s and 25 m/s were too high and do not allow enough drying time instead, the materials formed knots. Thus, these velocities and their corresponding temperatures were not appropriate for use in this dryer. At air velocity of 15 m/s all the materials went through and the combination of this velocity (15 m/s) with the air temperature of 90ºC the first constant moisture content of 12.4% was obtained. The same moisture content was also obtained at a temperature of 100°C and 110°C at air velocity of 15 m/s. The flash dryer is very effective in drying cassava mash; it can be used to dry products to safe storage moisture content level

Modeling of cassava peeling performance using dimensional analysis

Cassava peeling constitutes global challenge despite increasing consumption of its end products.  To provide scientific approach for mechanical peeling, the movement of tuber in the peeling chamber was analyzed and validated.  Dimensional analysis was used to establish model equations for predicting the relationship between dimensionless functional properties, and crop and machine parameters.   An improved cassava variety and 2014 model cassava peeler was used for the experiment. The effective machine speed varied from 100-140 r/min for smooth-edge and 140-160 r/min for serrated-edge cutting tool.  The results showed that when using smooth-edge; peeling efficiency (μ) was ranged from 84.97%-94.60%, mechanical damage (λ) was ranged from 1.57%-11.19%, peel retention (P) was ranged from 5.41%-15.03% and throughput (η) was ranged from 387.10-1046.50 kg/h.  When using serrated-edge, μ was ranged from 81.24%-91.36%, λ was ranged from 6.36%-8.41%, P was ranged from 8.64%-19.34% and η was ranged from 248.28-625.00 kg/h.  A linear relationship was established between the machine speed versus ratio of velocity of conveyance and peeling time

Development of a System for Fresh Fruit Juice Extraction and Dispensary

Abstract In Nigeria and many other African countries fruit juice is almost becoming a luxury found only on the table of the rich. Processing of raw fruits or juice concentrate into juice is done by large-scale industries resulting in high and unaffordable prices for the low income earners in developing countries. However the need for fruit juice in human diet cannot be over-emphasised. Although, the poor can eat raw fruits, the perishable nature of these fruits underscores the need for processing in order to make fruits available the year round. Locally available fruits that are widely grown in Nigeria include cashew, mangoes, watermelon, guava, pineapples, paw paws, oranges, tomatoes, tangerines, and many other indigenous fruits. Production of fruits in Nigeria can be estimated at hundreds of thousands of metric tones per year. Unfortunately, over 50% are lost due to perishable nature of fruits occasioned by high moisture content and poor post harvest handling and marketing strategies. In this study, a system for handling, processing and preservation of fruits was developed and tested. The system consists of the washing unit, the juice extraction unit, juice filtration, conditioning unit and dispensary unit. The system was packaged in a way to make juice available in the fresh form for consumption. Fruits such as orange, mango and pineapple could be processed to obtain 100% juice. A combination of one or more fruits is feasible to obtain mixed fruits. The systems provides for quick processing and dispensary of fresh fruits at affordable prices. The system has been introduced to some schools, villages, establishments and corporate organisations in Nigeria. Results show that majority accepted the product readily because of its positive health implications of fresh fruit without additives/ preservatives. The equipment used is affordable to small-scale industrialists. Thus, the system offers a sustainable approach for processing and consumption of fresh-fruit juice in developing countries. It is believed that the adoption of this system would enhance healthy living among the rural poor, provide employment, promote industrialisation and food security. The initial cost of the system was estimated at 1,500 US dollar