Effect Of Polycaprolactone/Polybutylene Terephthalate Spontaneous Modified Film Packaging On The Postharvest Storage Quality Of Kyoho Grape

This subject uses fully biodegradable polycaprolactone(PCL)as the matrix.By adding different proportions(10%,20%and 35%,w/w)of polybutylene terephthalate(PBAT)to melt and modify it.Blended films of PCL/PBAT(10%),PCL/PBAT(20%)and PCL/PBAT(35%)were prepared.By testing the mechanical properties,gas permeability,CO2/O2 selective permeability and water vapor permeability of blended films with different ratios.The PCL/PBAT(35%)blended film with better comprehensive packaging performance was selected for postharvest storage and preservation of Kyoho grapes.And use the perforated polypropylene(OPP)film packaging commonly used for packaging grapes on the market and the unpackaged group(CK)as a control group,And store the Jufeng grapes in a cold environment with a temperature of about 4?,The following research conclusions are drawn:(1)With the increase of PBAT,the Young's modulus and yield strength of the PCL/PBAT blended film both showed a downward trend,but its elongation at break showed an increasing trend.It shows that the addition of PBAT can improve the flexibility of PCL film.gas and water vapor test results show that the addition of PBAT can reduce the O2 and CO2 transmission rate and water vapor transmission rate of PCL/PBAT blended film,and has a high CO2/O2 selective transmission ratio(9.7).This shows that the addition of PBAT can improve the barrier properties of PCL films.(2)Compared with the PCL group and the commercially available punched unidirectional polypropylene(OPP)group,the PCL/PBAT(35%)packaging group can form a relatively low-oxygen,high-carbon dioxide atmosphere inside the Jufeng grape packaging.Keep the CO2 concentration in the bag at 8%to 10%and the O2 concentration at 2%to 3%.At the same time,the PCL/PBAT(35%)packaging group can significantly reduce the threshing rate,weight loss rate and rot rate after grape harvest,and maintain a high sensory score;In terms of maintaining nutrients,the PCL/PBAT(35%)packaging group can also maintain the grape's higher titratable acid content and Vc content.Which can extend the fresh-keeping period of Jufeng grapes to 18 days.It shows that the blended film prepared by modification has a certain development potential in the low-temperature modified atmosphere preservation of Jufeng grapes,which provides some theoretical basis for the development of new spontaneous modified atmosphere packaging materials.