The slope of the force-deformation curve is another measure that has been used to determine fruit maturity. Jarimopas and Kittawee (2007) subjected mango to slow compression to determine the relationship between firmness and maturity. They found that the slope remained constant from immaturity to maturity but decreased as the fruit became over-mature. Alternatively, maturity of a fruit can be found from the force response of the fruit at constant compression deformation. Takao and Ohmori (1994) successfully developed a hardness immaturity tester (HIT) based on experiments with kiwi fruit.