Mass and surface modelling of green plantain banana fruit based on physical characteristics

Abstract

The physical characteristic such as dimensional, projected area, volume, mass, and sphericity are directly related to the quality of a fruit. The consumer generally prefers the uniform size, mass, and shape of the fruit. Thermal properties are important to predict the heat flux or the time required for drying, freezing, refrigeration processing. The knowledge of these properties is essential for the process designing and development of equipment involved in carrying out different tasks such as grading, sizing, peeling, storage, and packaging system in the green banana processing industry (banana powder, banana chips, banana starch, banana-based soup, baby foods).The objective of this study was to determine the physical and thermal properties of plantain banana fruit as well as to develop mathematical models based on physical properties so that the same may be used to design various related equipment. The average dimension of fruit was 15.42, 4.08, and 3.59 cm as length (L), width (W), and thickness (T), respectively. The geometric mean diameter (Dg) and arithmetic mean diameter (Da) were measured as 6.08 and 7.7 cm, respectively. The sphericity, aspect ratio, and radius of curvature were found to be 39.60%, 0.27, and 186.49, respectively. The elongation and flakiness ratio was found to be 3.77 and 0.88, respectively. From measured physical properties, it was concluded that banana fruit is curved, non-spherical, elongated in shape. Linear, quadratic, power, and S-curve equations were applied to analyze the mass, surface area, and projected area of green banana fruit. The measured physical properties of fruit were statistically found significant at p < 0.05. The mass of fruit was best predicted via length as dimensional characteristics in the quadratic model (M = 305.37–36.50L + 1.46L2; R2 = 0.95; χ2 = 20.24; RMSE = 4.50). Whereas, the surface area of fruit was best predicted in the quadratic model based on ellipsoid spheroid volume (Vellip) (S = 25.34 + 0.87Vellip – 8.99Vellip2; R2 = 0.99; χ2 = 0.01; RMSE = 0.12) and projected area of fruit was best predicted in a power model produced by projected area perpendicular to length (PL) (PA = 0.69 PL0.91; R2 = 0.99; χ2 = 0.0; RMSE = 0.05). The thermal conductivity and specific heat of banana fruit were found to be 0.58 W/m°C and 3.86 kJ/kg°C, respectively.