Mineral oil migration from paper-based packaging into food,investigated by means of food simulants and model substances

ABSTRACT

Mineral oil hydrocarbons (MOH) are known to be mixtures of non-identified substances, which can migrate from, inter alia, recycled food packaging into food products. Such substances may have carcinogenic potential, which leads to a need to avoid their migration into food. In this article, we investigate the possible use of food simulants and model substances to simplify migration approaches. Tenax and Sorb-Star were chosen as simulant media. To stage the action of known components as a replacement for the migration of MOH, 16 single substances, including n-alkanes and aromatic compounds, were used. Kinetic studies were carried out at a maximum of 60°C with contact times of up to 14 days in touching contact with a medium or in gas-phase transfer to it. The results demonstrated that migration was predominantly a function of temperature, time and contact type, but it was also dependant on the molecular weight and polarity of the substances. Due to their low polarity, alkanes showed higher migration to the lipophilic food simulants than did pure aromatics without alkylation. Additionally, alkylated aromatics represent mineral oil aromatic hydrocarbons (MOAH) more realistically. In contrast to Tenax in the gas-phase transition, Tenax in touching contact may lead to overestimated values at higher temperatures. Migration values for Sorb-Star are in similar regions for both contact types. However, the values of the touching contact experiments were slightly higher than those of the gas-phase transfer. The results for Sorb-Star and Tenax with transport solely over the gas phase are also in good agreement. Sorb-Star generally represents an optimal simulant for chunky foods, whereas Tenax seems a good simulant for food types with a high contact surface. Temperatures up to 40°C are appropriate for most types of migration experiments, whereas 60°C should only be used as an option for experiments with Sorb-Star.     

Impact of transportation on silicon wafer‐based photovoltaic modules

Before a photovoltaic (PV) module is integrated into a PV system, it has to be handled and transported. Therefore, it is imperative to test the PV module for typical load situations occurring during the transport. We measure the vibration acceleration of PV module corners during transport handling and transport for well‐packed horizontal and vertical PV module stacks. We found a lower impact of vertical transports to cell cracks than for horizontal stacked modules. We found the highest random vibrations during a transport with a truck company with small trucks on bad roads. The reduced power spectral density (PSD) of this random vibration for horizontal transported modules is quite similar to the PSD spectrum suggested for testing of module packages in IEC62759‐1. We use this standard PSD at various mean acceleration levels to test the PV modules on a shaker and compare the cell cracks with those occurring during an accompanied real transport. Besides the PSD spectrum, we also measure shocks during the transport. An analysis of different sine shocks shows that 60‐cell modules are sensitive on shocks of more than 8 ms shock length. We suggest a combined application of a shock and PSD test procedure to reproduce realistic transport conditions. Copyright © 2016 John Wiley & Sons, Ltd.     

Deficiency of Thyroid Hormone Reduces Voltage-Gated Na+ Currents as Well as Expression of Na+/K+-ATPase in the Mouse Hippocampus

Mice lacking functional thyroid follicular cells, Pax8^−/− mice, die early postnatally, making them suitable models for extreme hypothyroidism. We have previously obtained evidence in postnatal rat neurons, that a down-regulation of Na⁺-current density could explain the reduced excitability of the nervous system in hypothyroidism. If such a mechanism underlies the development of coma and death in severe hypothyroidism, Pax8^−/− mice should show deficits in the expression of Na⁺ currents and potentially also in the expression of Na⁺/K⁺-ATPases, which are necessary to maintain low intracellular Na⁺ levels. We thus compared Na⁺ current densities in postnatal mice using the patch-clamp technique in the whole-cell configuration as well as the expression of three alpha and two beta-subunits of the Na⁺/K⁺-ATPase in wild type versus Pax8^−/− mice. Whereas the Na⁺ current density in hippocampal neurons from wild type mice was upregulated within the first postnatal week, the Na⁺ current density remained at a very low level in hippocampal neurons from Pax8^−/− mice. Pax8^−/− mice also showed significantly decreased protein expression levels of the catalytic α1 and α3 subunits of the Na⁺/K⁺-ATPase as well as decreased levels of the β2 isoform, with no changes in the α2 and β1 subunits.     

Process industries versus discrete processing: how system characteristics affect operator tasks

Cognition, Technology & Work - Despite an increasing level of automation, human operators still play a central role in industrial production. They need to monitor and adjust plant operations,...     

Improved automatic English proficiency rating of unconstrained speech with multiple corpora

The performance of machine learning classifiers in automatically scoring the English proficiency of unconstrained speech has been explored. Suprasegmental measures were computed by software, which identifies the basic elements of Brazil’s model in human discourse. This paper explores machine learning training with multiple corpora to improve two of those algorithms: prominent syllable detection and tone choice classification. The results show that machine learning training with the Boston University Radio News Corpus can improve automatic English proficiency scoring of unconstrained speech from a Pearson’s correlation of 0.677–0.718. This correlation is higher than any other existing computer programs for automatically scoring the proficiency of unconstrained speech and is approaching that of human raters in terms of inter-rater reliability.     

Development of formulations for reduced‐sugar and sugar‐free agar‐based fruit jellies

Because of the increasing consumer awareness of health‐related issues, there is a rising demand for noncariogenic, reduced‐energy confectionery products. This study was carried out to develop formulations for reduced‐sugar and sugar‐free, agar‐based jelly products. This was obtained by substituting sucrose and glucose syrup through a combination of sugar replacers, fibre, gelling agents and sweeteners. The application of a combination of polydextrose, oligofructose, sucralose and erythritol resulted in a sensory sweetness profile that was comparable to that of a sugar‐containing standard product. Concerning texture and sensory properties, reduced‐sugar and sugar‐free jellies processed using the respective formulations were comparable to the sugar‐containing standard products. Consumer evaluation using the Just‐about‐right technique exhibited satisfactory acceptance of the sugar‐free jellies.