Physico-mechanical Properties and Colour Characteristics of Apple as Affected by Methyl Jasmonate Treatments

Abstract

Physical (geometric, volumetric and colour) and mechanical properties of apple (cv. Fuji) as affected by Methyl Jasmonate treatments were analyzed. Geometric mean diameter, fruit mass, sphericity and surface area ranged from 71.36 to 69.97 mm, 196.53 to 194.83 g, 1.126 to 1.129, and 161.32 to 158.11 cm2 with MeJA doses, respectively. The bulk and fruit densities varied from 383.65 to 364.22 kg/m3 and from 967.96 to 954.63 kg/m3, with MeJA treatments. L*, a*, b* value of skin apple changed from 50.76 to 46.89, from 28.06 to 30.35, and from 24.58 to 22.43, respectively with MeJA doses. The skin and flesh firmnesses varied from 101.49 to 112.60 N and 74.18 to 72.71 N, respectively. The sphericity and projected area increased with MeJA doses used. As the MeJA doses increased, the bulk and fruit densities decreased, whereas volume increased. L*, b* and hue angle characteristics of skin apple were found to decrease, whereas a* was found to increase with MeJA doses. The fruit-removal-force was decreased linearly with increasing MeJA doses. The rubber surface offered the maximum friction followed by plywood and galvanized metal for MeJA doses.