The Preparation Of Ginger Stalk Cellulose And The Application In Membranes

The discard ginger skalk as a kind of solid waste mostly be stored directly in the field that produced a decay stink in a long time,or directly burned in the field which caused environmental pollution.Cellulose is a kind of natural renewable resources as the main composition of ginger skalk.Cellulose studied to investigate the properties of preparing packing membranes and then used in food packaging,was extracted from ginger skalk.It can provide a special way for the development of solid waste.Firstly,cellulose was extracted of discard ginger stalk by Potassium hydroxide(KOH)treatment.Through single factor experiment,the effections of KOH concentration,cooking time and liquid ratio on ginger stalk cellulose extraction were studied.The highest purity cellulose can be obtained,when the KOH concentration was 14wt%,extraction time was 5h and liquid ratio was 1:10.The cellulose characterization by TGA,FTIR,SEM and XRD.FTIR showed that the hemicellulose and lignin peaks disappeared after extraction.Thermal decomposition temperature increased from 225? to 317?,the thermal stability has been significantly improved.Secondly,cellulose packing membranes was prepared and its performance was studied.Through single factor experiment,the effections of cellulose content,melting temperatureand and coagulation bath temperature were studied,which influenced mechanical properties,moisture absorption rate and light transmittance of cellulose membranes.The optimal conditions for cellulose membranes preparation was that cellulose concentration of 4wt%,melting temperature at 100? and coagulation bath temperature of 20?.In this condition,tensile strength is 31.1MPa,and the elongation at break is 55.7%.Through the gas permeability test,the cellulose membrane has a certain permeability.Finally,strawberry preservation was researched by the packaging membranes.At first,the effect of the membrane materials on escherichia coli and staphylococcus aureus antibacterial activity was examined.Then membrane materials was used to pack strawberry at room temperature and under the condition of refrigeration,which showed that the effections for the strawberry sensory indexes,weightlessness rate,respiratory intensity and decay index at different time.The results showed that: when the content of gingerol reached 3wt%,escherichia coli bacteriostatic ring size is 10.5mm,staphylococcus aureus bacteriostatic ring size is 9mm respectively,and it can meet the antibacterial packaging requirements.The strawberries were compared between the packaging membranes and others of no packaging and packed in common plastic wrap strawberries.The composite membranes fresh keeping performance is better than the latter two,and the condition of refrigeration effect is better than ambient temperature.