Ana Rodríguez-Bernaldo de Quirós

Migration of Photoinitiators by Gas Phase into Dry Foods

Photoinitiators are components widely used in UV-cured inks for printing food packaging. In the present study, the migration of seven photoinitiators through the vapor phase was investigated. To perform the migration test, an additive enriched polyethylene wax was used as a source to release photoinitiators. The method was applied to evaluate the migration of the photoinitiators into five selected dry foods (cake, bread, cereals, rice and pasta). The highest level of migration was found in the cake. Parameters affecting the migration process were evaluated, and high migration level was found to correlate with both the porosity and the fat content. In addition, the kinetics of migration of the photoinitiators from the additive enriched wax into the cake were studied under accelerated conditions.

Photoinitiators: a food safety review

Ultraviolet light printing inks are considered safer than the classical inks; however, despite being on the outer surface of the packaging material, their components can migrate into foodstuffs and can give rise to contamination. Photoinitiators are a part of the formulation of printing inks, being an important class of migrant, for which there have been more than 100 incidents of contamination of packaged food with photoinitiators reported through Rapid Alert System for Food and Feed (RASFF) alerts in the European Union. In this review the process of photo-polymerisation is explained in depth to provide an insight into the complexity of the process, and the diversity of potential contaminants together with their degradation products. The critical factors affecting the migration process itself are reviewed, together with analytical methods and the current legislation in the European Union and other parts of the world.

Comparison of volatile components in raw and cooked green beans by GC-MS using dynamic headspace sampling and microwave desorption

Abstract The effects of four culinary treatments (steaming and boiling in a covered pot, a pressure cooker or a microwave oven) on the volatile component profile of green beans were evaluated. Volatile compounds in raw and cooked beans were analysed by means of dynamic headspace sampling onto an adsorbent, followed by microwave desorption into a gas chromatograph equipped with a mass spectrometric detector. Twenty-seven compounds were identified, including alcohols, aldehydes, ketones, esters, terpenes, sulphur compounds and alkenes. All of the thermal treatments caused important changes in the volatile compound profile in particular an increase in carbonyl compounds and a decrease in alcohol compounds, most notably in the case of the covered pot. It is concluded that the change in aroma during the cooking of green beans depends on compounds from lipid oxidation as well as compounds from other types of reactions, for instance the Strecker degradation.

Determination of vitamin E and carotenoid pigments by high performance liquid chromatography in shell of Chionoecetes opilio

This study reports the optimization of a method for the determination of vitamin E and carotenoids in shells of Chionoecetes opilio samples by online HPLC coupled with UV-vis and fluorescence detectors. The carotenoids were determined with diode-array detector (lambda 450 nm) and vitamin E with fluorescence detection (lambda(ex) 288, lambda(em) 331 nm). Two extractions methods were compared, saponification followed by an extraction step and a simple extraction with acetone. The last one was selected because allows to determine all compounds. Linearity, precisions and recoveries achieved for all compounds were satisfactory. Mean concentrations (mg per 100 g dry weight) were; 23.3 for vitamin E, 9.49 for astaxanthin and 0.2 mg for beta-carotene.

Rapid identification of volatile compounds in fresh seaweed

Volatile component profiles of fresh seaweed Laminaria spp and Undaria pinnatífida were analyzed using dynamic headspace for volatile profile evaluation, which allows the direct analysis of small quantities of sample without previous treatment and have been identified by GC-MS. Alcohols were the most important class of volatile compounds identified in Wakame and Kombu (25 and 29% respectively); nine alcohols were identified. The hydrocarbons group constitute the second most important family of volatiles, in both samples entire similar % area total 13-14%, being the butane the most abundant hydrocarbon. Aldehydes and halogenated compounds are higher in Laminaria spp (10-9% total area), whereas Undaria pinnatifida presents 4-0.23% respectively.

Determination of key diffusion and partition parameters and their use in migration modelling of benzophenone from low-density polyethylene (LDPE) into different foodstuffs

ABSTRACT The mass transport process (migration) of a model substance, benzophenone (BZP), from LDPE into selected foodstuffs at three temperatures was studied. A mathematical model based on Fick’s Second Law of Diffusion was used to simulate the migration process and a good correlation between experimental and predicted values was found. The acquired results contribute to a better understanding of this phenomenon and the parameters so-derived were incorporated into the migration module of the recently launched FACET tool (Flavourings, Additives and Food Contact Materials Exposure Tool). The migration tests were carried out at different time–temperature conditions, and BZP was extracted from LDPE and analysed by HPLC-DAD. With all data, the parameters for migration modelling (diffusion and partition coefficients) were calculated. Results showed that the diffusion coefficients (within both the polymer and the foodstuff) are greatly affected by the temperature and food’s physical state, whereas the partition coefficient was affected significantly only by food characteristics, particularly fat content.

Active food packaging based on molecularly imprinted polymers: study of the release kinetics of ferulic acid.

A novel active packaging based on molecularly imprinted polymer (MIP) was developed for the controlled release of ferulic acid. The release kinetics of ferulic acid from the active system to food simulants (10, 20, and 50% ethanol (v/v), 3% acetic acid (w/v), and vegetable oil), substitutes (95% ethanol (v/v) and isooctane), and real food samples at different temperatures were studied. The key parameters of the diffusion process were calculated by using a mathematical modeling based on Ficks second law. The ferulic acid release was affected by the temperature as well as the percentage of ethanol of the simulant. The fastest release occurred in 95% ethanol (v/v) at 20 °C. The diffusion coefficients (D) obtained ranged between 1.8 × 10(-11) and 4.2 × 10(-9) cm(2)/s. A very good correlation between experimental and estimated data was obtained, and consequently the model could be used to predict the release of ferulic acid into food simulants and real food samples.

Evaluation of oxygen absorber system effectiveness in butter containers

ABSTRACT The oxygen can have an adverse effect on the quality of some foods leading to a decrease in their shelf-life. Several approaches have been applied to remove the oxygen concentration in packed food; among them, oxygen scavengers have been widely used to preserve oxygen-sensitive foods. In the present study, an experimental set-up was designed to evaluate the effectiveness of oxygen scavengers, in removing oxygen from butter containers. Two types of oxygen absorbers adhesive labels and sachets and two caps with and without adjustable closure were tested. The plastic caps used in the study were characterized by differential scanning calorimetry and Fourier transform infrared spectroscopy. The oxygen concentration in the headspace of the containers was monitored using a gas analyser. The best results were achieved with the oxygen absorber sachets and using caps with adjustable closure. Under these conditions, the oxygen concentration inside the container remained below 3% during 150 h.

Trans-Stilbenes in Commercial Grape Juices: Quantification Using HPLC Approaches

Trans-stilbenes belong to the group of polyphenolic phytoalexins, and occur in many plant foods. These compounds have received great attention by researchers due to their well-known beneficial health effects. In the present study a chromatographic method that comprises the use of variable wavelength (VWD) and fluorescence (FLD) detectors in series for the analysis of trans-stilbenes is presented. The relation of peak-area obtained with both detectors is proposed as an alternative and complementary approach for the rapid identification of these phenolic compounds. The proposed method was applied to determine trans-stilbenes in commercial fruit juices. Trans-piceid was the most common trans-stilbene found in the samples analyzed. The method was validated in terms of linearity, sensitivity and repeatability. Appropriate sensitivity and good linearity (r2 > 0.9991) were achieved.

GC-MS Screening Analysis for the Identification of Potential Migrants in Plastic and Paper-Based Candy Wrappers

Food packaging materials may be a potential source of contamination through the migration of components from the material into foodstuffs. Potential migrants can be known substances such as additives (e.g., plasticizers, stabilizers, antioxidants, etc.), monomers, and so on. However, they can also be unknown substances, which could be non-intentionally added substances (NIAS). In the present study, non-targeted analysis using mass spectrometry coupled to gas chromatography (GC-MS) for the identification of migrants in plastic and paper-based candy wrappers was performed. Samples were analyzed after extraction with acetonitrile. Numerous compounds including N-alkanes, phthalates, acetyl tributyl citrate, tributyl aconitate, bis(2-ethylhexyl) adipate, butylated hydroxytoluene, etc. were identified. Many of the compounds detected in plastic samples are not included in the positive list of the authorized substances. One non-intentionally added substance, 7,9-Di-tert-butyl-1-oxaspiro(4,5)deca-6-9-diene-2,8-dione, which has been reported as a degradation product of the antioxidant Irganox 1010, was found in several samples of both plastic and paper packaging. The proposed method was shown to be a useful approach for the identification of potential migrants in packaging samples. The toxicity of the compounds identified was estimated according to Cramer rules. Then, a second targeted analysis was also conducted in order to identify photoinitiators; among the analyzed compounds, only 2-hydroxybenzophenone was found in five samples.