Acid Food Simulants Research Articles

Controlled release and antibacterial activity of corn starch-based films containing nanocellulose and thymol

The use of nanomaterials such as cellulose nanofiber (CNF) and antimicrobial compounds such as thymol (Thy), in starch films may improve the functional properties of films as active packaging films. This study quantifies the retention of thymol in corn starch (CS) and CS films containing cellulose nanofibers (CS/CNF) and investigates the migration of thymol from the films into a food simulant. A kinetic study was performed to evaluate the release of thymol from films into fatty acid food simulant (95% v/v ethanol) at 40 °C. The antibacterial activity of films was investigated via liquid culture assay. It was found that the addition of thymol significantly affects the surface morphology and cross-section of the films. CS/Thy and CS/CNF/Thy films retained thymol at 2.88 ± 0.50 and 11.21 ± 0.75 mg per g of CS/Thy and CS/CNF/Thy films, respectively. The release of thymol was affected by the presence of an intercalating network of CNF, which exhibited Fickian diffusion behavior. The release of thymol reached equilibrium within 48 h for CS/Thy, and 72 h for CS/CNF/Thy films. The CS/CNF/Thy film had a greater inhibitory effect than the CS/Thy film against Listeria monocytogenes and Salmonella Typhimurium. These findings demonstrate the potential applications of these films in improving the shelf life of perishable food products.

Effect of migration on the functionality of zinc oxide nanoparticle in polybutylene adipate terephthalate/thermoplastic starch films: A food simulant study

Active packaging relies on controlled release of antimicrobials for food protection; however, uncontrolled migration due to environmental factors poses safety and functionality challenges. This study investigated the stability of zinc oxide nanoparticle (ZnONP) in poly(butylene-adipate-co-terephthalate)/thermoplastic starch (PBAT/TPS) biopolymer film for active food packaging applications. While incorporating ZnONP significantly enhanced the properties and active functionalities (UV-light blocking, antimicrobial activity) of PBAT/TPS film, food simulants posed significant stability challenges. Notably, exposure to 3 % acetic acid (acidic food simulant) triggered complete detachment and dissolution of ZnONPs from the film surface, leading to pore formation and subsequent internal ZnO dissolution. This resulted in dramatic alterations to the bionanocomposite films, including increased opacity, water vapor permeability, and decreased thermal stability, mechanical properties, and active functionalities. In contrast, 10 % ethanol (aqueous food simulant) had minimal impact, suggesting higher ZnO stability in neutral environments. Importantly, ZnO migration analysis revealed thresholds for safe application: 1 % ZnONP for acidic food contact and up to 5 % for aqueous foodstuffs. These findings highlight the critical role of environmental factors in ZnONP stability and emphasize the need for strategic optimization of ZnO content for achieving both functionality and safety in active biopolymer packaging.

PHBV-based polymers as food packaging: Physical-chemical and structural stability under reuse conditions

Until recently, reuse models for food packaging plastics were generally considered burdensome. Today, reuse is placed second in the waste management hierarchy of the plastics circular economy. This work addresses, for the first time, the reuse of biobased and biodegradable materials such as PHBV and PHBV-quercetin. The safety and structural integrity of the materials were evaluated in two scenarios: (i) within a full reuse cycle including: food contact/detergentwashing/food contact; and (ii) successive washing operations in water, detergent and NaOH aqueous solutions. PHBV material that underwent the full reuse cycle using aqueous (10% ethanol) and acidic (3% acetic acid) food simulants showed an overall migration close to zero with a maintenance of its physical-chemical properties. It was also able to withstand up to 20 cycles of washing in water and detergent with slight changes in its intrinsic properties. Its washing with a 1 wt% aqueous NaOH solution, for one cycle, led to the removal of its external surface without altering its physical-chemical properties. The use of quercetin as additive had no consequence in the first scenario (the full reuse cycle). Even the migration of a part of it (2 wt% from the initial amount in the polymer) in the first contact with the food was far below the admissible daily intake. However, the release of quercetin during detergent washing steps and the production of acidic oxidation products during NaOH washing contributed to accelerate material degradation, questioning the use of such additives for PHAs.

High-performance thin-layer chromatography analysis of industrial bamboo tableware for genotoxins, melamine and formaldehyde

Bamboo tableware became popular as ecofriendly material. However, industrial tableware products made of bamboo-melamine–formaldehyde resin material are not biodegradable. In addition, harmful compounds were detected if such consumer articles were used with hot drinks or hot food, and risk assessment found that maximum daily dosages of melamine and formaldehyde were exceeded. High-performance thin-layer chromatography (HPTLC) methods for analysis of such samples have not been demonstrated so far, despite available HPTLC methods for the mentioned analytes. In this work, the potential and limitation of HPTLC analysis for bamboo-melamine–formaldehyde resin tableware was studied regarding the extractable presence of melamine, formaldehyde and genotoxins. The bamboo tableware was extracted with a food simulant, i.e. aqueous acetic acid simulating hot beverages, and analyzed neutralized and non-neutralized, directly without sample preparation to ensure sample integrity and to avoid loss of sample components. As a result, melamine was not detected in the acidic food simulant. Unfortunately, the existing formaldehyde method was not applicable due to the acidic milieu of the food simulant. The non-target HPTLC−(S9)-SOS-Umu-C bioassay with and without simulated S9 liver enzyme metabolization found no genotoxic substances in 50 µL food simulant, which volume and thus acidity was the maximum tolerated by the Salmonella cells.

Inhibitory Effect against Listeria monocytogenes of Carbon Nanoparticles Loaded with Copper as Precursors of Food Active Packaging.

Human listeriosis is a serious foodborne disease of which outbreaks are occurring increasingly frequently in Europe. Around the world, different legal requirements exist to guarantee food safety. Nanomaterials are increasingly used in the food industry as inhibitors of pathogens, and carbon nanomaterials are among the most promising. In the present study, novel carbon nanoparticles loaded with copper (CNP-Cu) were prepared, and their antimicrobial activity against Listeria monocytogenes was assessed. CNPs of two sizes were synthesized and characterized by dynamic light scattering (DLS), electrophoretic light scattering (ELS) and electron microscopy (EM). The minimum inhibitory concentration (MIC) of CNP-Cu was determined in accordance with the available standard. To get insights into its mechanism of action, the release of copper ions into a cell media was assessed by inductively coupled plasma optical emission (ICP-OE), and the ability of loaded CNPs to generate cytotoxic reactive oxygen species (ROS) was evaluated by EPR spectroscopy. Finally, the extent of release of copper in a food simulant was assessed. The results demonstrated the antimicrobial effectiveness of CNP-Cu, with growth inhibition up to 85% and a release of copper that was more pronounced in an acidic food simulant. Overall, the results indicate CNP-Cu as a promising agent for the design of active food packaging which is able to improve food shelf-life.

Production of chitosan and poly (vinyl alcohol) films functionalized with hop extract (Humulus lupulu L. var. Cascade) for food packaging application

In this study, chitosan and poly(vinyl alcohol) (PVOH) films functionalized with hop (Humulus lupulus L. var. Cascade) extracts were produced for food packaging application. The film form solution was prepared by the casting technique, adding 30%, 50%, and 70% of PVOH (2% w/w) in chitosan (2% w/w), and then, functionalized with 10%, 20%, and 40% (v/v) of hop extracts. The mechanical, color, morphological, thermal, and antioxidant properties were investigated. The results indicated that the addition of PVOH improved the flexibility of the films, and the functionalization with hop extracts produced more rigid films. The addition of hop extracts decreased the luminosity, resulting in yellow and green colored films. High antioxidant capacity by DPPH and ABTS assays was observed in the films containing hop extracts. The release study demonstrated that the films can release antioxidant compounds in aqueous and acid food simulant. In conclusion, the physicochemical, mechanical, and antioxidant properties of chitosan/PVOH films were improved with the addition of the hop extracts, indicating that the functionalized material is a promising alternative for active packaging in food system.

Hybridization of 5-nitroisatin and silver nanoparticles for boosting the antimicrobial performance of poly(lactic acid)/nanocellulose nanocomposite films

This study aims to produce poly(lactic acid) (PLA)/corn cob nanocellulose (CCNC) with enhanced antimicrobial properties. Silver (Ag) is a good antimicrobial agent, but it will cause adverse effects upon the human cells in high exposure concentrations of silver ions. Hence, the objective of this study is to assess the viability of partial substitution of silver nanoparticles (AgNP) using 5-nitroisatin (NI) as an antimicrobial agent for the PLA/CCNC. The antimicrobial efficiency of PLA films was measured using Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The agar disc diffusion assay and antimicrobial activity on the plastic surfaces showed that hybridization of the NI and AgNP can give a synergistic antimicrobial effect on the PLA/CCNC nanocomposite. The inhibition zone of PLA/CCNC-5/Ag/NI is larger compared to PLA/CCNC-5/Ag and PLA/CCNC-5/NI. The PLA/CCNC-5/Ag/NI recorded > 4 log reduction, which indicates 99.999% of growth inhibitory. The silver ion migration from the PLA nanocomposite films was assessed using an inductively coupled plasma-optical emission spectrometer (ICP-OES). It was found that the silver migration from the PLA/CCNC-5/Ag/NI nanocomposite after one week exposure to acetic acid food simulant is still below the European Food Safety Authority regulated level. We can observe that the PLA/CCNC-5/Ag/NI demonstrated lower silver migration (0.037 mg/L) and a higher antibacterial inhibition zone compared to PLA/CCNC-5/Ag. 5-nitroisatin not only partial replacement of AgNP (reduce the dose of AgNP), but it gives a boosting on the antimicrobial performance for the PLA/CCNC-5 nanocomposites.

Effect of Organic Modifier Types on the Physical-Mechanical Properties and Overall Migration of Post-Consumer Polypropylene/Clay Nanocomposites for Food Packaging.

The deterioration of the physical–mechanical properties and loss of the chemical safety of plastics after consumption are topics of concern for food packaging applications. Incorporating nanoclays is an alternative to improve the performance of recycled plastics. However, properties and overall migration from polymer/clay nanocomposites to food require to be evaluated case-by-case. This work aimed to investigate the effect of organic modifier types of clays on the structural, thermal and mechanical properties and the overall migration of nanocomposites based on 50/50 virgin and recycled post-consumer polypropylene blend (VPP/RPP) and organoclays for food packaging applications. The clay with the most hydrophobic organic modifier caused higher thermal stability of the nanocomposites and greater intercalation of polypropylene between clay mineral layers but increased the overall migration to a fatty food simulant. This migration value was higher from the 50/50 VPP/RPP film than from VPP. Nonetheless, clays reduced the migration and even more when the clay had greater hydrophilicity because of lower interactions between the nanocomposite and the fatty simulant. Conversely, nanocomposites and VPP/RPP control films exhibited low migration values in the acid and non-acid food simulants. Regarding tensile parameters, elongation at break values of PP film significantly increased with RPP addition, but the incorporation of organoclays reduced its ductility to values closer to the VPP.

Migration kinetic of silver from polylactic acid nanocomposite film into acidic food simulant after different high-pressure food processing.

The migration study of nano-Ag migration from polylactic acid (PLA) films was studied. Samples treated by high-pressure food processing (0, 100, 200, 300, and 400MPa pressure) were soaked in acetic acid solution and incubated at 20°C for 90 days. At the end of storage, nano-Ag particles (AgNPs) migration from the PLA/AgNPs composite film treated under 200MPa high pressure was the lowest. However, AgNPs migration was accelerated under 400MPa high pressure. High-pressure processing (200MPa) could cause denser structure and higher crystallinity degree in films than other treatments. Lower amount of AgNPs induced a decline in the intensity of specific characteristic peaks. The diffraction peak intensity of α-crystal for the film sample treated with 400MPa was the lowest on day 60. The crystallization index of the PLA matrix changed with different high-pressure processing. The result indicated that appropriate high-pressure food processing could effectively suppress AgNPs migration from PLA-based film while contacting with acidic acid food simulant. PRACTICAL APPLICATION: The release of nanoparticles from food packaging material is a very important matter when the migration is concerned with regulatory and toxicity issues. The study described the migration kinetic of AgNPs from PLA nanocomposite film into acidic food simulant after different high-pressure food processing. The results indicated that the PLA/AgNPs nanocomposite film was safe for acidic food after high-pressure treatment.

Designing active mats based on cellulose acetate/polycaprolactone core/shell structures with different release kinetics

Core/shell electrospun mats based on cellulose acetate (CA) and polycaprolactone (PCL) were developed as novel active materials for releasing quercetin (Quer) and curcumin (Cur). The effect of polymeric uniaxial and coaxial electrospun systems and the chemical structures of Quer and Cur on the structural, thermal, and mass transfer properties of the developed mats were investigated. Release modelling indicated that the diffusion of the active agents from the uniaxial PCL fibers was highly dependent on the type of food simulant. Higher diffusion coefficients were obtained for both active agents in acid food simulant due to the higher swelling of the electrospun mats. In addition, CA/PCL coaxial structures slowed down the diffusion of both active agents into both food simulants. CA increased the retention of the active compounds in the polymer structure, resulting in partition coefficients values higher than the values obtained for uniaxial active PCL mats.

Safety concerns of recycling postconsumer polyolefins for food contact uses: Regarding (semi-)volatile migrants untargetedly screened

Plastic recycling is one of the important ways to mitigate plastic pollution. However, chemicals present in recycled plastics is one of the key qualities affecting their potential uses and deserves more attention. 475 migrants coming from 15 postconsumer recycled polyolefins were identified by direct immersion-solid-phase micro-extraction gas chromatography mass spectrometry (DI-SPME-GC-MS) and atmospheric pressure-gas chromatography-quadrupole-time of flight-mass spectrometry (APGC-QTOF-MS). About 60 % of them might not be of human risk because they were food additives/components or they are saturated hydrocarbons, fatty acyls, or prenol lipids. Most of them had molecular weight (MW) between 150 and 210 Da, though, high concern substances with high MW (e.g. octocrylene) implied that high MW surrogates are required to study the efficiency of recycling processes for polyolefins. The mean predicted octanol/water partition coefficient (XLogP) was about 6.5 and 3.5 for 95 % ethanol and 3 % acetic acid food simulants, respectively. Octocrylene, 1-tetradecene, 1-dodecene, dodecyl acrylate, 2,4-di-tert-butylphenol, 1,4-benzenedicarboxylic acid, diethyl ester, benzenamine, 2,4-dichloro-, and diethyl phthalate were of high concern depending on the potential food contact use of the materials. The results presented are informative and can be of great help for recyclers and law makers to recycle polyolefins for safe food contact use.

Development of Active Barrier Multilayer Films Based on Electrospun Antimicrobial Hot-Tack Food Waste Derived Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and Cellulose Nanocrystal Interlayers.

Active multilayer films based on polyhydroxyalkanoates (PHAs) with and without high barrier coatings of cellulose nanocrystals (CNCs) were herein successfully developed. To this end, an electrospun antimicrobial hot-tack layer made of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) derived from cheese whey, a by-product from the dairy industry, was deposited on a previously manufactured blown film of commercial food contact PHA-based resin. A hybrid combination of oregano essential oil (OEO) and zinc oxide nanoparticles (ZnONPs) were incorporated during the electrospinning process into the PHBV nanofibers at 2.5 and 2.25 wt%, respectively, in order to provide antimicrobial properties. A barrier CNC coating was also applied by casting from an aqueous solution of nanocellulose at 2 wt% using a rod at 1m/min. The whole multilayer structure was thereafter assembled in a pilot roll-to-roll laminating system, where the blown PHA-based film was located as the outer layers while the electrospun antimicrobial hot-tack PHBV layer and the barrier CNC coating were placed as interlayers. The resultant multilayer films, having a final thickness in the 130–150 µm range, were characterized to ascertain their potential in biodegradable food packaging. The multilayers showed contact transparency, interlayer adhesion, improved barrier to water and limonene vapors, and intermediate mechanical performance. Moreover, the films presented high antimicrobial and antioxidant activities in both open and closed systems for up to 15 days. Finally, the food safety of the multilayers was assessed by migration and cytotoxicity tests, demonstrating that the films are safe to use in both alcoholic and acid food simulants and they are also not cytotoxic for Caco-2 cells.

Monitoring of metals migration and identification of corrosion sources in canned tomatoes and sardines

ABSTRACT The evaluation of the migration of metallic elements in the metal containers is usually performed through the direct analysis of the cans’ content. However, this may be biased by exogenous factors causing contamination of food prior to the canning process. In this context, the separation between exogenous factors and endogenous ones due to the effective migration of metal elements from the containers is often not taken into account. In the present study, we focus on endogenous sources linked to manufacturing defects in metal cans or to the heat treatment operation applied during the canning process. An assessment of the harmless of metal cans was performed for tomato and sardine cans marketed in Tunisia. Cans filled with simulants or food were heat-treated according to industry procedures and stored for an extended period of time. The survey was conducted up to 18 months for cans filled with simulants and until ca. 36 months for those filled with food. Concentrations of potentially migrating metals (Fe, Zn, Cd, Al, Cu, Pb, and Sn) were evaluated using ICP-OES. The inner surface of the cans was examined by SEM/EDX. The obtained results showed high migration levels of Fe and Zn in cans filled with acidic food simulant or tomato paste or sardines in tomato sauce, resulting from corrosion of the inner sides of the cans and the uncoated junction seals. Cadmium was only detected in cans filled with food and is of exogenous origin. Low migration levels of Al, Cu, Pb, and Sn were recorded.

Temperature and pH affect copper release kinetics from copper metal foil and commercial copperware to food simulants

ABSTRACTCopper (Cu) metal and alloys are used in cookware and other food contact surfaces due to their desirable properties for various applications. However, Cu metal can ionise and subsequently transfer to food and beverages under certain conditions. Here, we tested how pH and temperature affected Cu release kinetics using model systems utilising Cu metal foil and commercially available copperware. Cu foil and copperware were exposed to food simulants composed of 3% (w:w) aqueous solutions of citric acid, malic acid, acetic acid, or deionised (DI) water at temperatures ranging from 4°C to 60°C. An additional pilot experiment tested how simulated long-term cleaning affected subsequent Cu release from lined and unlined copperware to 3% citric acid. Food simulants were then analysed by ICP-MS for total Cu. After 180 min, incubation of Cu metal foil with acid-containing food simulants at 4°C resulted in Cu release ranging from 8.7 - 14.0 µg cm−2, while 21.5–38.1 µg cm−2 was released at 60°C. In contrast, Cu transfer from metal foil to DI water was relatively low, with <0.6 µg cm−2 released after 180 min at 60°C. With citric acid food simulant, lined copperware released between 0.6 and 3.0 µg Cu cm−2 over 180 min at the set temperatures, while unlined copperware released approximately 25–45 fold higher amounts of Cu (26.9–74.6 µg cm−2) over this same time period. In contrast, use of DI water food simulant resulted in Cu release of <0.1 µg cm−2 for the lined copperware and <2 µg cm−2 for the unlined type. No significant effect of simulated long-term cleaning on Cu release from copperware was observed. These data indicate that Cu release is affected by temperature and pH, and that specific steps can be taken to limit Cu metal release from food contact surfaces to foods and beverages.

Leaching of Iron and Zinc into Food Simultant from Tin Can Packaging

Cans are widely used as primary packaging in various food products. Ferrous (Fe) and zinc (Zn) metal as the constituent components in the manufacture of can packaging bodies can experience corrosion and dissolve in food so that it will affect food quality and finally affect to health. This study aimed to determine the content of Fe and Zn metal at different treatments (time) with 3% acetic acid and vegetable oil as food simulators on can packaging using Atomic Absorption Spectrophotometer (AAS). The results of the analysis showed that the range of Fe and Zn metal content in 3% acetic acid food simulants were respectively 0.15-27.46 mg/kg and 0.00060.007 mg/kg, while in vegetable oil simulants 3% Fe and metal content Zn were 0.6-2.46 mg/kg and 0.00040.0025 mg/kg with 80-100% recovery, respectively. Thus, food from can packaging should not be exposed to oxygen for a long time, especially when it has been opened because it will increase the leaching of Fe and Zn metals from the packaging into food.

Migration of copper from nanocopper/polypropylene composite films and its functional property

Nanocopper with different concentrations was introduced to homopolymer polypropylene (PP-H) matrix to prepare nanocopper/PP-H composite film. Film appearance, mechanical and thermal properties were investigated. Migration test to 3% acetic acid (w/v) food simulant, film antibacterial ability and human hepatotoxicity were conducted to further evaluate film safeness. FTIR results suggest that nanocopper particles were physically dispersed in PP-H matrix and the addition of nanocopper could significantly improve thermal and mechanical properties of composite films, ensuring its potential utilization for food packaging. Also, the composite film showed great antibacterial ability including Escherichia coli, Staphylococcus aureus, Shigella castellani and Bacillus subtilis. At 70 ℃, when the initial concentration of added nanocopper reached 1% (w/w) or higher, the concentration of copper migrated from film to acetic food simulant would reach to 4.5 μg/g and would start damaging L-02 cells. This study provides important information for the potential utilization of nanocopper in food packaging films.

Migration of metal elements from polylactic acid dinner plate into acidic food simulant and its safety evaluation

Abstract The metal elements in polylactic acid (PLA) dinner plate were determined by inductively coupled plasma optical emission spectrometer (ICP-OES); migration of these metal elements from PLA dinner plate into 3% acetic acid food simulant at 40, 60 and 70 °C was investigated; three subsequent migration experiments under 40 °C for 10 days and 70 °C for 2 h to simulate migration under multiple-use conditions were conducted. The results revealed that the PLA dinner plate contains aluminum, barium, calcium, iron, magnesium, titanium and zinc. As expected, with the exposure time and temperature increases, the migration of metal elements increased; even after a long exposure time (40 °C for 10 days, 60 °C for 6 days, 70 °C for 6 days), the migration still continued. Migration of aluminum, barium, iron, and zinc was not exceed their specific migration limit (SML), while the estimated daily intake (EDI) of calcium and magnesium was not beyond their tolerable upper intake level (UL). The overall migration into acidic food simulant was not exceed overall migration limit (OML). For three subsequent migration experiments, the results revealed that the migration mainly occurred from the surface of PLA dinner plate when the exposure time is shorter, while the migration not only occurred from the surface but also from the interior of PLA dinner plate when the exposure time is long.

Back Propagation Artificial Neural Network Modeling and Migration Analysis of Siloxane D5 Migration from Selected Food Contact Materials

The detection and quantification of environmental pollution compounds migration in food contact silicone rubber materials remains a prospective issue to be solved in the consideration of toxicology and safety assessment. In this study, an artificial neural network (ANN) model was established to predict migration property of non-target compound decamethylcyclopentasiloxane (D5) molecule in food contact silicone rubber. The average prediction accuracy of the model was 99.8%. The analysis of ANN indicates that high temperature condition accelerates the migration of D5 from silicone rubber into two typical food simulants, namely H2O and acetic acid. The migration of D5 is more apparent when the silicone rubber is in contact with acetic acid. The combination of experiment and simulation analysis of D5 migration indicates that high temperature and acetic acid food simulant environment threaten the safety of food contact silicone rubber. These fundamental studies can provide a comprehensive understanding of the migration of cyclic organosiloxane oligomer from silicone rubber and guidance for the safety evaluation and early warning mechanisms.

Bioactive starch nanocomposite films with antioxidant activity and enhanced mechanical properties obtained by extrusion followed by thermo-compression

In this work bioactive starch films with antioxidant activity were developed by extrusion followed by thermo-compression. Rosemary extract was incorporated into starch-glycerol films in different concentrations (2.5%, 5% and 10% w/w with respect to starch). Despite the high mechanical and thermal energy involved during extrusion, rosemary polyphenols remained in the films without losing its activity.Starch nanocomposites were obtained by the incorporation of rosemary nanoparticles, which were formed from the immiscible components of the extract. For low extract concentration, homogeneously dispersed nanoparticles acted as reinforcement of the matrix, increasing stress and strain at break without modifying Young's modulus. At high concentration, the mechanical response was ruled by the miscible components of the extract, which acted as an additional plasticizer. In this case, nanocomposite films with higher values of strain at break and lower values of Young's modulus and stress at break were obtained. All the developed films released a high percentage of polyphenols to hydrophilic, lipophilic or acid food simulants in a short time interval. Experimental release data was fitted by Weibull equation in order to elucidate release mechanisms.According to the results of this research, rosemary extract can be incorporated into starch films by extrusion without previous encapsulation. Despite thermal and mechanical energy involved in the process, the rosemary compounds kept their antioxidant activity and were released from the bioactive films.

Migration of titanium dioxide from PET/TiO2 composite film for polymer-laminated steel

ABSTRACTPET/TiO2 composite film is the most widely used film for polymer-laminated steel, and the migration of TiO2 is very important for the safety evaluation of its packaged food. Microwave digestion, wet digestion and dry ashing were used for pretreatment of composite film to determine the content of TiO2 in composite film. Migration tests were carried out at 40°C, 60°C and 80°C 4% using acetic acid and 50% ethanol as the acid and ester food simulants. The migration amount of TiO2 was determined by inductively coupled plasma optical emission spectrometry (ICP-OES). With increasing temperature and time, the migration of TiO2 increased. In 4% acetic acid, the migration amount of TiO2 at 40°C for 10 days was 1.88 mg kg−1 and the migration amount at 80°C for 8 h was 3.32 mg kg−1, indicating that the effect of temperature on migration was more obvious. Under the same conditions, the migration amount of TiO2 in 4% acetic acid was greater than in 50% ethanol. X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimeter (DSC) were used to analyse the crystal structure, morphology, chemical groups and thermal properties of the film before and after the migration tests. The results showed that filmTiO2 had a stable rutile type crystal structure and it was almost uniformly distributed. PET and TiO2 were combined with strong chemical bonds. After TiO2 migration, the crystallinity and the glass transition temperature (Tg) of the film decreased, but the change of melting temperature (Tm) was not obvious.