Development and evaluation of Modified Atmosphere (MA) packages employing lamination technique for Royal Delicious apple

Modified atmosphere (MA) packages were prepared for Royal Delicious apple with an aim to achieve the optimum storage atmosphere within the packages in minimum possible time. Apples were harvested at their commercial maturity and respirtion rate of the fruits was measured at temperatures between 0 – 25°C. On the basis of preliminary investigations, air composition with 3% O2 and 3% CO2 was found appropriate for MA packaging of apple. The MA package was finalized with a size of 24 cm x 19 cm for 1 kg fill-weight of apples. As the gas transmission rates of individual polymeric films could not match the gas transmission requirements of MAP, judicious combinations of the films were made to bring gas transmission characteristics close to the required values. The equilibrium concentrations of O2 and CO2 were established within 36-72 h under different storage temperatures. The mathematical model, developed applying enzymatic kinetics based respiration equation coupled with the Arrhenius model, effectively predicted the equilibrium time and the levels of O2 and CO2 at equilibrium. MA packages were evaluated through assessment of different quality parameters of apple during storage and were found to increase its shelf life by 125-210% that of unpacked fruits at different storage temperatures.