Evaluating the efficacy of modified atmosphere packaging (MAP) to reduce mechanical injury and quality loss of broccoli

Package cushioning is one of the most important preserving methods to help protect fresh produce from potential mechanical damage caused by shock and vibration. While modified atmosphere packaging (MAP) is considered as the effective tool for maintaining quality and extending shelf life of fresh produce through alterations of its physiological activities and subsequent quality changes, the benefit of MAP films on reduction of mechanical injury has not been yet clarified. We, therefore, examined the combined benefit of MAP (gas/humidity control) and the physical protection (cushioning) of broccoli during transport and shelf life. By using the vibrating simulator (truck transport simulation), broccoli heads under five different packaging conditions were treated with the acceleration of 5.22 m s^-1, sweep mode at the frequency range of 5-25 Hz for 2 h. Samples for quality assessment were taken immediately after the treatment (Day 0) and during three days at 20°C. From the results, we found that the MAP treatment efficiently reduced the mechanical injury caused by transport vibration. Moreover, MAP significantly reduced weight loss and maintained chlorophyll and sugar content of stored broccoli florets. The MAP effect on reduction of mechanical injury during transport and on quality maintenance during shelf life of broccoli was confirmed. The gene expression analysis relating cellular response metabolisms of broccoli to MAP response will also provide useful information regarding the selection of an optimum packaging condition for broccoli.