Estimating Mass and Volume of Nigerian Grown Sweet and Irish Potato Tubers using their Geometrical Attributes

Abstract

Sweet and Irish potato are tuber crops which have been domesticated and cultivated in different parts of the world including Nigeria. They are often prepared in various ways for food. A good knowledge of the physical properties of these tuber crops will enhance proper design of post-harvest processing machines and handling equipment with high level of performance. Also, functional relationships established between the various physical properties of these crops could assist in ensuring proper handling and more efficient and economical processing. This study was therefore, aimed at developing mathematical models for predicting the mass and volume of sweet and Irish potato tubers using some of their geometrical attributes. The research was conducted on fresh sweet and Irish potato tubers which were sorted into four fractions based on their individual mass. The physical characteristics measured include the mass, volume, linear dimensions (length, width and thickness) and the projected areas taken along the three mutually-perpendicular axes. The models were divided into three classifications namely: single and multiple variable regression models based on linear dimensions; single and multiple variable regression models based on the projected areas; single variable regression models based on mass or volume. Mass and volume models based on the projected areas and the volume were the best models for both crops. The highest coefficient of determination (R2) for sweet potato was obtained for mass model based on the projected area along the longitudinal plane (R2 = 0.981) while mass model expressed on the basis of the multiple regression of the three linear dimensions performed best (R2 = 0.968) for Irish potato. This study provided useful information that can help in the design of systems for handling and processing of sweet and Irish potato tubers.