Preparation of antioxidant active films based on chitosan: diffusivity study of α-tocopherol into food simulants.

New active films based on chitosan and polycaprolactone blends and containing α-tocopherol were designed for food packaging applications. Mechanical properties, stability against temperature and swelling degree in 50 % ethanol (v/v) were evaluated. Migration kinetics of α-tocopherol from the developed films into butter and food simulants [50 % ethanol (v/v), 95 % ethanol (v/v), and isooctane] at different temperatures were studied. α-Tocopherol was quantified in the food simulants by means of high performance liquid chromatography with diode-array detection at 292 nm. The proposed method exhibited a good sensitivity with a limit of detection of 0.1 mg/L. The kinetics release of α-tocopherol was characterized by determining the partition and the diffusion coefficients by using a mathematical modeling based on Fick's Second Law. The diffusion coefficients obtained ranged between 1.03 × 10(-13) and 2.24 × 10(-12) cm(2)/s for 95 % ethanol (v/v) at 4 and 20 °C, respectively. Developed films maintained the antioxidant activity for more than 20 days.

Instability of an aromatic amine in fatty food and fatty food simulant: characterisation of reaction products and prediction of their toxicity.

It is a well-known fact that amines are not stable in food of a fatty nature. In this study the synthesis and characterisation of the products obtained as a result of the reaction of amines in a fatty medium are reported. Based on the well-known reactions among amines and acid and esters groups, two novel compounds were synthesised using m-xylylenediamine (mXDA), a primary diamine widely used as monomer in the manufacture of food contact materials and two fatty acids, oleic acid and palmitic acid, which occur in most fats. The resulting compounds were two molecules belonging to the family of fatty acid amides, dioleamide and dipalmitamide. A complete characterisation of both products was carried out employing several techniques such as infrared spectroscopy, (1)H- and (13)C-NMR spectroscopy, electron ionisation mass spectrometry, LC-MS/MS and UV spectrometry. The results obtained by the different techniques were well correlated. In the second part of the work, the formation of these compounds in real samples was evaluated. For this purpose a certain volume of olive oil was spiked with a known amount of mXDA. Olive oil was selected as a fatty medium since it is a widely consumed food and additionally is used as a fatty food simulant in migration studies of food contact materials. A method was developed to extract the fatty acid amides from the fatty matrix, which were then identified by LC-MS/MS. The toxicity of the synthesised compounds was predicted using a toxicity estimation software tool.

Simultaneous chromatographic analysis of photoinitiators and amine synergists in food contact materials.

Photoinitiators (PIs) are components of UV-cured inks widely used in printing of food packaging. These substances can migrate into food and may be a hazard to human health. High-performance liquid chromatography with diode-array detection (HPLC-DAD) has been used for analysis of PIs and amine synergists in food packaging. Analysis was performed with a Kromasil C18 column (250 mm × 3.2 mm i.d., 5 µm particle size) with a binary mobile phase gradient prepared from acetonitrile and Milli-Q water. The flow rate was 0.5 mL min(-1). The method enables separation of fourteen PIs and amine synergists in a single run. The method was validated for linearity, repeatability, and limits of detection and quantification. Excellent sensitivity (LODs ≤ 1.56 µg dm(2)) and appropriate repeatability (RSD (n = 10) <0.9%) were achieved. Different types of food packaging material including plastic films, cardboard, and cans were analyzed and PIs were detected in 47% of the samples tested (n = 17). Positive samples were confirmed by use of LC-MS-MS in positive electrospray ionization (ESI) mode.

Ultra-high pressure LC for astaxanthin determination in shrimp by-products and active food packaging.

Nowadays, there is increasing interest in natural antioxidants from food by-products. Astaxanthin is a potent antioxidant and one of the major carotenoids in crustaceans and salmonids. An ultra-high pressure liquid chromatographic method was developed and validated for the determination of astaxanthin in shrimp by-products, and its migration from new packaging materials to food simulants was also studied. The method uses an UPLC® BEH guard-column (2.1 × 5 mm, 1.7 µm particle size) and an UPLC® BEH analytical column (2.1 × 50 mm, 1.7 µm particle size). Chromatographic separation was achieved using a programmed gradient mobile phase consisting of (A) acetonitrile-methanol (containing 0.05 m ammonium acetate)-dichloromethane (75:20:5, v/v/v) and (B) ultrapure water. This method was evaluated with respect to validation parameters such as linearity, precision, limit of detection, limit of quantification and recovery. Low-density polyethylene films were prepared with different amounts of the lipid fraction of fermented shrimp waste by extrusion, and migration was evaluated into food simulants (isooctane and ethanol 95%, v/v). Migration was not detected under the tested conditions.

Migration of bisphenol A from polycarbonate baby bottles purchased in the Spanish market by liquid chromatography and fluorescence detection.

During the last decade the safety of bisphenol A (BPA) monomer in polycarbonate baby bottles has drawn the attention of both the public and the scientific community. This paper presents the results of BPA migration from polycarbonate baby bottles bought in the Spanish market, into simulant B (3% acetic acid), 50% ethanol and into real food (reconstituted infant formula). Furthermore, it was also the objective of this study to assess the suitability of 50% ethanol as a simulant for infant formula. BPA was analysed by a multi-analyte liquid chromatography method with fluorescence detection and mass spectrometry confirmation. The method was in-house validated and accredited by the national accreditation body. The validation results for this analyte in the previous mentioned matrices were: LOD = 0.004-0.007 mg kg(-1); LOQ (validated) = 0.03 mg kg(-1); RSD% = 3.4-5.8; and recovery = 106.6-118.2%. A collection of 72 different baby bottle samples from 12 different brands were analysed. Baby bottle material was identified by FTIR. The migration test conditions used were those recommended for baby bottles in the Guidelines on testing conditions for articles in contact with foodstuffs (with a focus on kitchenware), prepared by the European network of laboratories for food-contact materials. In most of the migration assays the results were below the LOD. In four of the commercial brands there was detectable migration into the simulant 50% ethanol and BPA was detected in only two samples of infant formula (0.01 mg kg(-1)). Migration results obtained were in compliance with European Union regulations.

Migration and diffusion of diphenylbutadiene from packages into foods.

Monitoring of exposure to chemicals from food contact materials is a subject of increasing importance. The concentration of the chemicals and their migration levels, as well as food consumption and packaging usage data, are required to enable calculation of the degree of such exposure. The present study investigated the migration kinetics of diphenylbutadiene (DPBD) from packages into flour, rice, honey, milk powder and toast. Migration was not always negligible, except in honey and skimmed milk powder. Experiments carried out with starch alone enabled us to conclude that diffusion of migrants occurred through starch and fat. Key diffusion parameters were determined (diffusion coefficient and partition coefficient) based on Fick's second equation. The following diffusion coefficients were obtained at 25 degrees C: 2.7 x 10(-10), 3.4 x 10(-11), 3.2 x 10(-10), 8.4 x 10(-11), 8.1 x 10(-11) cm(2) s(-1), for wheat flour, rice, milk powder and toast, with 4 and 21% fat, respectively. A very good fit between experimental and predicted data was achieved. The data obtained in the present study confirm the validity of the mathematical model for predicting migration from Food Contact Materials (FCM) into foods.