Vol. 10, Issue 3 (2021)

Author(s):
Shilpa S Selvan, L Edukondalu, A Ashok Kumar and M Madhava

Abstract:
Engineering properties of sweet oranges are very important to optimize the design parameters of processing equipment. The knowledge of engineering properties of sweet oranges is important for the design of grading, conveying, processing and packaging systems. Some engineering properties of grade I (>150 g), grade II (130-150 g), grade III (110-130 g) and IV (<110 g) sweet oranges were investigated. This study was undertaken to determine some important engineering properties such as axial dimensions, equivalent diameter, sphericity, surface area, individual fruit weight, volume, bulk density, true density, coefficient of friction and firmness of for the design of grading or sorting machine for sweet orange fruits. The shapes of the fruits were found to be round and the size of the fruits was characterized using length, width and thickness of fruits. The average volume of the fruits ranged from 177.86 to 100.76 cm³; the individual fruit weight ranged from 175.52 g to 100.23 g and the average sphericity ranged from 0.976 to 0.970 whereas the range of fruit size was observed to be 67.64 to 54.56 mm from grade I to grade IV, respectively. The bulk density for the fruits varying from 564.47 kg/m³ to 533.06 kg/m³; and the true density varies from 967.70 kg/m³ to 957.80 kg/m³, respectively. The coefficient of friction of the sweet orange fruits on glass, GI (galvanized iron) sheet and plywood surfaces of four grades were ranges from 0.19 to 0.26. The force required to penetrate the fruits on stem, centre and tail ends of sweet orange fruits was found to 37.62, 26.29, 21.98 and 19.35 N, respectively. Maximum penetration force was found in grade I fruits at the tail end because of more compactness of the fruit and the minimum value was observed at centre portion of grade I fruits. Results shows that the four grades of sweet orange fruits were significantly different from each other regarding their engineering properties.