Study On The Preparation Of Da-KGM/Chitosan Blend Films And Its Application In Fresh-keeping Of Sweet Corn

Currently,the fresh-keeping film for fruits and vegetables is mainly plastic.However,this material could not be naturally degraded,and there also have some hidden danger for people’s health and safety.In order to solve this problem,paper packaging products and biodegradable plastics materials were also launched.Nevertheless,owning to its high costly,these materials were also hard-promoted.Therefore,it has been a long-term research hotspot to seek a kind of material that has good performance,biodegradable,and no threat to human’s health.Duing to easy-biodegradable,good performance of film,polysaccharide-based films is good candidate for plastic wrap and has gradually got people’s attention.In this paper,deacetylation Konjac glucomanna(referred to as da-KGM)and Chitosan were selected to prepare complex da-KGM/chitosan blend films,and its tensile strength,elongation and membrane WVP as evaluation indexes,to discuss degree of deacetylation,da-KGM/Chitosan ratio,concentration and glycerin dosage were used to determine the effect of compound film.The optimum technological conditions for membrane technology were comfirmed,and it will provide important reference data for the key technology and parameters of the film process.The effect of blend film on fresh-keeping for stween com was also discussed.The main results are as follow:1.Ca(OH)2 solution was selected to perpare deacetylation KGM.A serial of blend films were made from da-KGM and Chitosan.The tensile strength,elongation and WVP of blend films were selected as evaluation indexes to discuss influence of degree of deacetylation,da-KGM/Chitosan ratio,concentration and glycerin dosage on compound film.The data of blend film’s orthogonal test showed that degree of deacetylation,da-KGM/Chitosan ratio,concentration and glycerin dosage of KGM complex film has great influence on films’ Characteristics.The optimum technological conditions for blend films:degree of deacetylation 0.70,da-KGM/Chitosan ratio 3:7,concentration 1.5%and glycerin dosage 0.50mL.2、The results of structural analysis displayed that there are a lot of ntramolecular and intermolecular hydrogen bond were formed between da-KGM and Chitosan molecular chain.It caused thess molecular chain became tightness,resulting the surface of blend films became very smooth and present a certain rule of configuration.3.In order to test actual efficiency of blend films,the films were applied to fresh-keeping of sweet corn.Common preservative film and control group(did not have any treatment)were used to compare with.The results showed that the blend film treatment can effectively control the increased trend of hardness of sweet corn,reduce weightlessness rate of sweet corn in storage period(compare with control group 87%),which indicated that the blend film can effectively lessen moisture loss of sweet corn.The blend film treatment can effectively restrain product respiration rate,postpone the decreasing rate of soluble solid,starch,total sugar of sweet corn,and the content of Vc of product can maintain at a high level.It suggested that blend film exhibited a good fresh-keeping,and was able to become a good candidate to replace plastic materials.This blend film is a potential Food packaging film and will has considerable commercial value and broad prospects.