The effect of temperature and type of impact surface on critical drop height of apple

الملخص EN

Fruit bruising is one of the most important factors which are limiting the mechanization and automation in harvesting, handling and transport of fruits and vegetables, including apple.

Because of importance of dynamic loads in handling systems, it is useful to identify the conditions that cause in reducing the rate of bruising under impact loads.

According to the results of this research, factors of temperature, type of impact surface and kinetic energy are affected on rate of bruised surface area (P<0.01).

By increasing temperature of fruit tissue, the rate of bruise decreased, while the kinetic energy had the inverse effect.

In addition, by increasing the hardness of impact surface the rate of bruise was increased, so that the minimum and maximum rate of bruise were related to corrugated carton (0.97%) and galvanized iron (2.26%), respectively.

This result may be stated in the form of drop height, so that, in Red Delicious variety, the maximum value of critical drop height was related to corrugated carton and temperature of 10 °C, equal to 130 mm, while the minimum value was related to galvanized iron and 0 °C, equal to 26 mm.

However, the results showed that Golden Delicious apple had more resistance to bruising than the Red Delicious