This study was conducted to determine the physical properties of fresh and dried Tiger nut which are essential for designing engineering processes, material handling, storage, equipment design and fabrication. Samples of Tiger nut were collected from the market (Ekeonunwa), both fresh and sun dried was used as sample A and B respectively. Some selected physical properties of Tiger nut were determined at moisture content levels of wet basis only, the moisture content level for each samples are A=39.4% and B=14% . The average length, width, thickness (dimensional size), weight, geometric mean diameter, arithmetic mean diameter, sphericity index, aspect ratio, surface area, projected area, volume, true density, bulk density and porosity were determined. The dimensional size (length, width, thickness) were 10.72mm, 9.35mm, 11.13mm3 for A and 9.28mm, 8.22mm, 9.81mm for B, while the weight for the both sample was 0.88g and 0.51g. The bulk density, true density porosity and the volume were found to be 1.60g/ml, 1.05g/ml, 42.86%, 584.15mm3 for sample A.0.63g/m/, 1.08ml, 42.50% and 396.22mm3 for sample B respectively.
KEY WORKS: Tiger nut, dimensional properties, and Gravimetric properties.
1.1 BACKGROUND OF THE STUDY
Tiger nut (Cyperus esculentus) is an underutilized crop in the family of Cyperaceae, which produce rhizomes from the base and tubers that are somewhat spherical. Tiger nut tubers contain about 8% protein and have 20-30% tiger nut oil, which is nourishing to the epidermis (Alobo & Ogbogo, 2007). The necessary essential minerals, calcium, magnesium and iron required for bones, tissue repairs, muscles and blood stream, as well as vitamin B that assist in balancing the central nervous system is contained in tiger nut tubers (Oladele & Aine, 2007). Chevalier (1996) also reported that tiger nut tuber could be used for the treatment of flatulence, indigestion, diarrhea, dysentery and excessive thirst and contain higher essential amino acids than those proposed in the protein standard by the FAO/WHO (1985) for satisfying adult needs (Bosch et al; 2005).
Understanding the physical properties of food is important as they are used in process design, product and process optimization, product development, food quality control and food process modeling.
Information on physical properties of tiger nut needed in design, of machines used during harvesting, separating, cleaning, handling and storage of the nut and converting them into food, feed and fodder is scarce. Hence, the properties which are useful during design must be known.
1.2 STATEMENT OF PROBLEM
Many work has be done on tiger nut, such as processing and preservation; but no work has be done on physical properties of tiger nut in order to ascertain suitable machinery for its process and production. In most of the countries, production of tiger nut into different product such as flour, beverages etc were a challenge to producers. As a result of this, there is need to ensure that all potential sources of tiger nut are exploited effectively and utilized industrially, study on physical properties of tiger nut will form a platform for mechanization of the process. That is;
The study is to determine the physical properties of tiger nut in order.
- To construct agricultural machinery.
- To improve process design and food process modeling
- To develop the product and food quality control
- To increase its utilization as a food resources.
1.3 AIM AND OBJECTIVE OF THE STUDY
The project work is aimed to investigate some physical properties of tiger nut that is needed in design of machines and processes.
1.4 SCOPE OF THE STUDY
The current study, sought to determine some physical properties of tiger nut, which are relevant to the mechanization of its processing in order to increase its utilization as a food resource. These include size, shape, surface area, volume, density, porosity, arithmetic mean diameter, geometric diameter, weight, sphericity determination and finally the moisture content. (Wet basis).
1.5 JUSTIFICATION OF THE STUDY
Tiger nut is commonly underutilized in Nigeria; it is well grown and available in semi-dried form. Its tubers can be eaten unprepared, roasted with sugar etc. (Umerie, et al; 1997). This work intends to increase its utilization as a food resource by determining some physical properties that aids to mechanization of its processing such as harvesting, separating, cleaning, handling, packaging and storage.