Changes in Rheological Properties and Electric Conductivity of Bananas during Artificial Afterripening

Abstract

Concerning quantitatve determination of the degree of maturity of bananas during artificial afterriepening, measurements were carried out on their electric conductivity and rheological parameters such as hardness, elasticity, brittleness, cohesiveness, adhesiveness and gumminess. The degree of maturity was evaluated with sugar content and pH, and through sensory tests as well. To discuss electric conductivity, a numeric factor ‘n’ was used, which was obtained from the observed current-voltage relation on the basis of the theoretical expression of current due to diffusion of ions:
I=I₀[exp(ZFV/nRT)-1],
where R is the gas constant, ZF electronic charge, V applied voltage and T absolute temperature.
Sugar content, n and pH increased in process of days, and reached at a maximum value when bananas got edible.