P. Paseiro

Mineral content of the honeys produced in Galicia (North-west Spain)

Abstract Sodium, potassium, calcium, magnesium, copper, iron, manganese, phosphorus (phosphate), chlorine (chloride), silicon (silica), sulphur (sulphate), and ash contents of 91 samples of raw honey from Galicia (NW Spain) were determined. The mean ash content was 0.408%. Potassium was the most abundant of the elements determined, with an average content of 1572 mg/kg (38.5% of the ash). All mineral contents showed high coefficients of variation, ranging from 0.34 (sodium, calcium, and sulphur) to 0.71 (iron). In general, the Galician honeys studied have high mineral contents in comparison with honeys reported in the literature.

Typical diffusion behaviour in packaging polymers - application to functional barriers

When plastics are collected for recycling, possibly contaminated articles might be recycled into food packaging, and thus the contaminants might subsequently migrate into the food. Multilayer functional barriers may be used to delay and to reduce such migration. The contribution of the work reported here is to establish reference values (at 40°C) of diffusion coefficients and of activation energies to predict the functional barrier efficiency of a broad range of polymers (polyolefins, polystyrene, polyamide, PVC, PET, PVDC, [ethylene vinyl alcohol copolymer], polyacrylonitrile and [ethylene vinyl acetate copolymer]). Diffusion coefficients (D) and activation energies (Ea) were measured and were compiled together with literature data. This allowed identification of new trends for the log D = f(molecular weight) relationships. The slopes were a function of the barrier efficiency of the polymer and temperature. The apparent activation energy of diffusion displayed two domains of variation with molecular weight (M). For low M (gases), there was little variation of Ea. Focusing on larger molecules, high barrier polymers displayed a larger dependence of Ea with M. The apparent activation energy decreased with T. These results suggest a discontinuity between rubbery and glassy polymers.

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.

Validation of a liquid chromatography–mass spectrometry method for determining the migration of primary aromatic amines from cooking utensils and its application to actual samples

Many cooking utensils are made of nylon, a material that may incorporate azodyes and where primary aromatic amines (PAAs) are the starting substances. Moreover, aromatic amines may also be present as technical impurities. Another source of PAAs could be aromatic isocyanates used as monomers in the production of polyurethanes. The aim of this work was to validate a simple LC–MS/MS method for the determination of eight primary aromatic amines (m-phenylenediamine, 2,6- and 2,4-toluenediamine, 1,5-diaminonaphthalene, aniline, 4,4′-diaminonaphenylether, 4,4′-methylenedianiline and 3,3′-dimethylbenzidine) in the aqueous food simulant 3% acetic acid (w/v). The detection limits calculated were adequate with respect to present legislation. The method was validated at four concentration levels (2, 5 10 and 20 µg kg−1). Global internal reproducibility was in the range 5.6–21.4% (RSDR) depending on the compound and concentration. Mean recoveries for all levels varied between 89 and 100%, depending on the amine. A total of 39 samples of cooking utensils were analyzed using the described method and the results obtained after the third migration test were not compliant in approximately half of the samples.

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.

Ultra‐high pressure LC determination of glucosamine in shrimp by‐products and migration tests of chitosan films

Chitosan, a multiple applications molecule, was isolated from shrimp by-products by fermentation. The amount of chitosan in the solid fraction of the fermented extract was measured after its conversion in the respective glucosamine units. The procedure includes an acid hydrolysis (110 °C, 4 h with HCl 8 M) and a derivatization with 9-fluorenylmethyl chloroformate (Fmoc-Cl). Ultra-high-pressure liquid chromatography method was developed and optimized. Excellent peaks resolution was achieved in just 10 min. The method was evaluated in what concerns to validation parameters such as linearity, repeatability, quantification limit, and recovery. Migration tests of films prepared with chitosan were carried out in two simulants: ultrapure water and ethanol 95% (v/v).

Silicon, phosphorus, sulphur, chlorine and ash contents of Spanish commercial honeys

ZusammenfassungIn 24 Honigproben aus dem spanischen Handel wurden Silizium (Si), Phosphor (P), Schwefel (S), Chlor (Cl) und der Aschegehalt bestimmt. Die Mittelwerte (mg/kg) lagen bei 3.2 für Si, 78 für P, 45 für S und 262 für Cl. Die Gehalte an Phosphor und Chlor waren deutlich höher als bei Honigen aus anderen Ländern. Der mittlere Aschegehalt war 0.19%. Die Variationskoeffizienten aller Inhaltsstoffe waren relativ hoch.AbstractSilicon, phosphorus, sulphur, chlorine and ash contents were determined in samples of 24 Spanish commercial honeys. Mean contents (mg/kg of honey) were 3.2 for silicon, 78 for phosphorus, 45 for sulphur and 262 for chlorine. The values for phosphorus and chlorine are high with respect to honeys from other regions. Mean ash content was 0.19%. In all cases there were high coefficients of variation, ranging from 0.43 for silicon to 0.58 for phosphorus.

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.