The Research And Development Of Bio-enzymatic Preservation Paper

Myrica is the specialty fruit of China,Myrica matures in the season of high temperature and raininess,and having no exocarp makes myrica very difficult to preserve and convey.And also myrica is very easy to deteriorate,The storage and transportation has become a bottleneck of myrica industry and also attracted great concern of the local government and farmers.Therefore,the study of myrica preservation technology has a very important significance in terms of both ecological effects and economic efficiency.In this paper,the bio-enzymatic preservation paper was prepared by the use of glucose oxidase.It was a kind of specialty paper with deoxidizing effect.Work having been done in this paper is as follows,firstly,the best carrier of the immobilization of glucose oxidase was selected from various kinds of carriers,and then the immobilized glucose oxidase was prepared.Secondly,the immobilized glucose oxidase and pasting anionic starch were mixed to make preservative coating,and then the bio-enzymatic preservation paper was prepared by coating the preservative coating on food packaging base paper.Lastly,the physical properties,deoxidation performance and the applications on myrica preservation of the bio-enzymatic preservation paper were studied.For the first above purpose,studied on the immobilization of glucose oxidase,the best carrier for immobilizing glucose oxidase was gaseous SiO₂ with a specific surface area of 300m²/g.And the optimum conditions for immobilizing glucose oxidase were as follows: reaction temperature was 30 ?,pH value was 5.1,enzyme dosage was 0.5mg,glutaraldehyde concentration was 0.10%,crosslinking time was 3h.Under these conditions,the recovery of enzyme activity of immobilized glucose oxidase was 75%.In addition,the immobilized enzyme increased storage stability and dispersion stability,The storage stability of GOD was higher than that of free glucose oxidase?GOD?.After 60 days of storage,the immobilized GOD activity remained more than 90% of the original activity,while the free GOD activity was reduced to70%.According to FT-IR result,characteristic peaks of immobilized glucose samples occurred at1637cm^-1,1110cm^-1 and 1540cm^-1,in the 1637 cm^-1 occurred the C = N stretching vibration peak,it was mainly attributed to the formation of Schiff base,which indicated that the GOD was immobilized in the gaseous SiO₂ and the secondary structure didn't changed.Subsequently,The preparation of bio-enzyme preservation paper was studied,When the immobilized GOD was 6g,distilled water was 74 g,and 15% anionic starch was mixed to prepare coating,the solid content of the prepared coating was 9.6%.With the increase of the dosage amount of the preservative coating,the oxygen-removing effect of the bio-enzymatic preservation paper gradually increased,too.When the amount of the preservative coating was 8g/m²,the amount of immobilized enzyme was 4.4g/m²,the oxygen content was reduced by 56%in 250 minute at room temperature?25 ??,so the deoxidation effect was very remarkable.Eventually,The results showed that the preservation of myrica by bio-enzyme preservation paper,the oxygen content and the amount of ethylene produced in the storage environment were significantly reduced.Through the analysis of myrica Physiological changes of the study,shows that the use of bio-enzyme preservation paper preserved myrica,myrica storage to the first four days began to rot.Storage 6d,rate of intact fruit was using uncoated food packaging paper more than 2 times,which made myrica a longer shelf life.