Overall Migration and Calcium Migration from Biodegraded Polylactic Acid Composite Films into Food Simulant

KeyWord:food contact material  bio-degradation film  polylactic acid£¨PLA£©  calcium carbonate  migration  ultraviolet aging

Abstract:

      While biodegradable plastics continually exhibit many excellent properties£¬their safety has been increasingly concerned£®In this study£¬the migration risk of calcium in food contact degradation composite film was evaluated£¬with polylactic acid£¨PLA£© and polylactic acid/poly£¨butyleneadipate-co-terephthalate£© £¨PBAT£© as the substrates and calcium carbonate £¨CaCO3£© as the inorganic filler£®The calcium concentrations in five kinds of PLA/PBAT/CaCO3 composite films with various contents of CaCO3 were determined by inductively coupled plasma optical emission spectrometry£¨ICP£­OES£©£®Meanwhile£¬ the PLA/PBAT/CaCO3 films were characterized by scanning electron microscopy£¨SEM£©£®The overall migration of PLA/PBAT/CaCO3 films into three food simulants£¨3% acetic acid£¬10% ethanol£¬95% ethanol£© were investigated£¬and the relationship between the overall migration results and the calcium content was explored£®Migrations of calcium from PLA/PBAT/CaCO3 films into the acidic food stimulant of 3% acetic acid at 40 ¡æ/24 h and 70 ¡æ/2 h were investigated£¬respectively£®Furthermore£¬effect of ultraviolet aging treatment on the migration was also studied£®Results showed that the overall migration of the five composite films into 95% ethanol was higher than that into 10% ethanol£¬and the overall migration into 3% acetic acid exceeded the overall migration limit£¨OML£©£¬which may lead to food safety risks£®The overall migration was mainly affected by CaCO3£¬and the calcium concentration had a linear relationship with the overall migration into 3% acetic acid£®With the increase of CaCO3 content£¬different degrees of agglomeration occurred on the surface of the films£¬while the migration of calcium was affected by the agglomeration£®For all the composite films with different CaCO3 contents£¬the migration equilibriums were obtained in a short time£¨40 ¡æ£¬4 h£©£®The long time£¨more than 24 h£© UV aging for composite film inhibited the calcium migration due to the cross-linking of PBAT£®The safety of these biodegradable composite films as food contact materials is worth further study£®