Identification And Safety Analysis Of Disposable Starch-based Meal Tableware

Starch-based tableware,including disposable meal boxes,forks,spoons and knives,is a common bio-based tableware in the current market.When starch-based tableware comes into contacet with food,its intentionally or non-intentionally added substances may migrate to food,which may cause food safety hazards.In this study,the characterization,screening and migration of potential risk substances of disposable starch-based tableware derived from the different manufacturers were studied,and its safety was evaluated.The main research contents of this paper are as follows:(1)The samples random purchased from the market of what were declared to be a disposable starch-based spoons,forks and meal boxes were analyzed by combining SEM,TAG and ATR-FTIR.The results showed that in addition to two of them were non-starch-based meal boxes,the others were starch-based materails that were mixed with PP materials by unpatsted starch;and the starch-based meal boxes were named S-A,S-B,S-C…S-F,respectively,according to its starch content frow low to high.There were obvious starch paticles on the surface of starch-based meal box S-A,S-B and S-D,while the surface of the box S-C,S-E and S-F had hole structure,which may be related to the total starch content and processing process.(2)The disposable starch-based meal boxes were screened for potential risk substances by using GC-MS,HPLC and ICP-MS.The results showed that thiabendazole,o-phenyl phenol,diphenyl and imazalil four common anti-mold agents were not detected;malathion,difenoconazole,oxadiazon and fosthiazate pesticide residues were matched from 100 pesticide mass spectrometry libraries in the meal box S-A,S-B,S-C and S-D,respetively.In addition,the metal element residues and its migration were not beyond the corresponding national standard limit.It was worth mentioning that isopropyl palmitate,isopropyl stearate,9-octadecenamide,alkanes,Irgafos 168 and I168O were found in disposable starch-based meal boxes.(3)The content of Irgafos 168 and I168 O in disposable starch-based meal boxes and their migration behavior in isooctane as oily food simulants(70 ℃)were detected by GC-MS.The effects of UV exposure(254 nm),microwave heating(800 W)and high humidity(RH=80%,T=36 ℃)on the migration of Irgafos 168 and I168 O to isooctane(70 ℃,2 h)were studied.The results showed that the content of Irgafos 168 and I168 O between meal boxes was significantly different(P < 0.05),and the content range were(39.12±0.43～1038.94±56.48)mg/kg and(35.76±0.19～1106.94±85.68)mg/kg,respectively.The migration of Irgafos 168 and I168 O in isooctane(70 ℃)increases with prolonging time and it reached equilibrium after 40 min,which conforms to the general migration law.It also showed that the higher the initial content of the substance,the greater its migration,and the holes in the surface of the meal box also promoted its migration.The migration of Irgafos 168 decreased with the increased of UV irradiation time,but the migration of I168 O increased initially and decreased afterwards.With the increase of microwave time,the migration of Irgafos 168 and I168 O decreased,but high humidity treatment had no significant effect on their migration(P > 0.05).The migration of Irgafos 168 in isooctane(70 ℃,2 h)was lower than the national standard limit of 60 mg/kg;and I168 O was identified as Granmer Ⅲ substance,the estimated daily intake of I168 O was 14 to 151.5 μg/d,the maximum of which was higher than the threshold of toxicological concern.(4)The effect of temperature and humidity on the surface microbial contamination of starch-based meal boxes and the degradation behavior of starch-based meal boxes by using composting bacteria bury method were studied.The microorganisms were cultured by potato dextrose agar plate and identified as mold by the color,morphology,texture and microscope identification,because the characteristics of the bacteria conformed to the general characteristics of mold appeared on the surface of the starch-based meal boxes.The number of mold colonies contained and the degradation or splitting of starch-based lunch boxes under composting bacteria bury between starch-based lunch boxes were varied.More importantly,the starch content of the meal box,surface distribution and amylose/amylopectin ratio were some important factors for the difference in mildew.In addition,it was found that starch on the surface of the meal box mainly degraded,which accelerated the degradation speed of the meal box.