title: Eco-friendly biorefractory films of gelatin and TEMPO-oxidized cellulose ester for food packaging application.
abstract: BACKGROUND
  In recent years, many types of food-packaging films and composites have been prepared using gelatin because of its good film-forming ability, non-toxic nature and cost-effectiveness. However, the relatively weak thermal stability, poor mechanical properties and easily-degradable quality limit the potential application of gelatin as a practical material. Microcrystalline cellulose (MCC), which comprises one of the most abundant biomass resources, has been regarded as a safe and reliable food additive because it has the same ingredients as the cellulose in people's daily intake. Food-packaging films with the excellent properties provided by gelatin and oxidized-cellulose represent a topic of great interest.
  
  
  RESULTS
  MCC was modified by 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-mediated oxidation and chosen as the base of the macromolecule cross-linker (TMN). After modification of gelatin film by TMN, the minimum amount of free -NH2in solution was 4.8 × 10-4mol g-1). The thermal property obviously increased (from 322.31oC to 352.63oC) and was crucial for usage in the food industry. The highest water contact value 123.09° (η = 25%) indicated a better surface hydrophobicity. The higher Eab(58.88%) and lower Em(77.16%) demonstrated that a more flexible and shatter-proof material was obtained. Water vapor uptake studies suggested increased moisture absorption and greater swelling ability.
  
  
  CONCLUSIONS
  The film material obtained in the present study was safe, stable, eco-friendly and biorefractory and could also be decomposed completely by the environment after disposal as a result of the properties of the ingredients gelatin and cellulose. The incorporation of a cellulosic cross-linker to gelatin-based films was an ideal choice with respect to developing a packaging for the food industry. © 2016 Society of Chemical Industry.
authors.affiliation: Shandong Provincial Key Laboratory of Fine Chemicals, Qilu University of Technology, Jinan, PR China.
authors.forename: Chen
authors.initials: C
authors.lastname: Zhuang
authors.affiliation: Shandong Provincial Key Laboratory of Fine Chemicals, Qilu University of Technology, Jinan, PR China.
authors.forename: Furong
authors.initials: F
authors.lastname: Tao
authors.affiliation: Shandong Provincial Key Laboratory of Fine Chemicals, Qilu University of Technology, Jinan, PR China.
authors.forename: Yuezhi
authors.initials: Y
authors.lastname: Cui
mesh_terms: D001704:Biopolymers / Q000737:chemistry*; D002483:Cellulose, Oxidized / Q000737:chemistry*; D003497:Cyclic N-Oxides / Q000737:chemistry*; D004952:Esters / Q000737:chemistry*; D018857:Food Packaging / Q000295:instrumentation*; D005780:Gelatin / Q000737:chemistry*; D010084:Oxidation-Reduction; D010539:Permeability; D012995:Solubility; D013696:Temperature
chemical_list: D001704:Biopolymers; D002483:Cellulose, Oxidized; D003497:Cyclic N-Oxides; D004952:Esters; C015233:gelatin film; D005780:Gelatin; C003959:TEMPO
keywords: biodegradation; cross-linking; gelatin; oxidized cellulose; packaging material