| Broccoli has a very powerful nutritional and healthy function.However,broccoli quickly deteriorates due to its strong respiratory metabolism,results in yellowing and nutritional value loss at 2-3 d under normal temperature.Numerous studies have shown that controlled atmosphere is the most effective preservation method,and various types of modified atmosphere packaging(MAP)are proposed for the preservation of agricultural products on this basis.For MAP,a large amount of research has focused on membrane materials,whereas those membrane materials are difficult to achieve uniform standards,due to different membrane characteristics.In addition,the gas interaction between the packages is also the key to restrict the logistics transportation.In this study,non-permeability package membrane was selected to explore the impact of O2/CO2 active modified atmosphere packaging on the storage quality and residual effects of broccoli,the aim was provided a reference for the preservation of broccoli during logistics.The main findings are as follows:1.At 1? and 20?,the inatial gas proportion of 80%O2+20%CO2,90%O2+10%CO2,100%O2 and CK(natural air)were designed.At 10?,the inatial gas proportion of 60%O2+40%CO2,70%O2+30%CO2,80%O2+20%CO2,90%O2+10%CO2 and CK were designed.Respiration rate,weight loss rate,color and relative conductivity,pH,and chlorophyll,VC,malonaldehyde(MDA),ethanol,acetaldehyde contents of broccoli florets and the O2,CO2 contents in the package were measured at regular intervals during storage under 90%-95%relative humidity.The results showed that at 1?10 and 20?,90%O2+10%CO2,70%O2+30%CO2 and 100%O2 treatments,the gas proportion quickly balanced in container,kept respiration rate of broccoli head more low and stable,reduced the decreases in pH and color of broccoli head,inhibited the increases in relative conductivity,weight loss and ethanol,acetaldehyde,MDA contents,and maintained chlorophyll and VC contents of broccoli florets during storage.The shelf life of broccoli at 1,10,and 20? were 21,16,and 4 d,respectively.2.In view of the previous studies,the optimal treatments were selected to explore the residual effects under 10? and 20?.At 10?,the treatments of 70%O2+30%CO2 and CK were designed and taken Air as control,after all samples were treated for 3 d and 6 d respectively,remove the MAP and transfer to 10? and 20? under natural air storage.At 20?,the treatments of 100%O2 and CK were designed and taken Air as control,after all samples were treated for 2 d and 4 d respectively,remove the MAP and transfer to 20?under natural air storage.Under the above storage conditions,respiration rate,weight loss rate and rot rate,pH,color,chlorophyll,VC,total soluble solid(TSS),soluble protein,MDA,ethanol and acetaldehyde were periodically observed in broccoli head or florets.The results showed that the better residual effects were occurred both 70%O2+30%CO2 treatment for 6 d at 10? and 100%O2 treatment for 4 d at 20?,and it could disperse off-flavors such as ethanol and acetaldehyde in a short time,and better restored the levels of pH and MDA,significantly maintained the storage quality of chlorophyll,VC,TSS,and soluble protein content,and its shelf life was 18(6+12)and 6(4+2)d,respectively,while natural air treatment was only 9 d and 2 d at 10 ? and 20 ?.In addition,the residual effect on shelf life of 70%O2+30%CO2 treatment for 6 d at 10? was 1 d at least higher than other treatments during storage at 20?. |
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