Voorbij de kroniek : over het belang van theatertijdschriften

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FLAT_SPACE!

Een first person shooter in een netwerkopstelling van 8 computers bieden de toeschouwer de mogelijkheid om te spelen in een areana die getextureerd is met texturen die doorgestuurd werken door een grote selectie van kunstenaars en architecten.status: publishe

The Kinetics of beta-Elimination of Cystine and the Formation of Lanthionine in Gliadin

When gliadin, a mixture of wheat storage proteins containing only intramolecular disulfide (SS) bonds, is heated at high temperatures and preferably at alkaline pH, the SS bonds are cleaved by beta-elimination reactions leading to decreased cystine levels and the generation of dehydroalanine (DHA) and free sulfhydryl (SH) groups. DHA and the free SH group of cysteine can further react to form the irreversible' cross-link lanthionine (LAN). The kinetics of this reaction were studied by heating model systems containing gliadin at different pH values (pH 6.0, 8.0 and 11.0) at temperatures up to 120 degrees C. Multiresponse modeling was applied to simultaneously describe the course of the reaction partners, intermediates and products. The estimated kinetic parameters indicate that the reaction rate constant for the elimination reaction increases with temperature and pH. Moreover, the predominant reaction consuming the intermediary DHA is the cross-link with cysteine to form LAN following second-order reaction kinetics. The corresponding reaction rate constant is less dependent on temperature and pH. Use of the proposed kinetic model to estimate reaction product concentrations in cereal-based foods allowed us to conclude that the beta-elimination reaction may be less important during, e.g., bread making, but may well contribute to gluten network formation during the production of soft wheat products. It may also well be relevant in the production of bioplastics made from gluten.status: publishe

Processing tomato pulp in the presence of lipids: the impact on lycopene bioaccessibility

Industrial processing of tomatoes into different end-products includes mechanical treatments, several thermal treatment steps, and the addition of ingredients which might induce changes in lycopene bioaccessibility. Here the influence of high pressure homogenisation (HPH) (100bar) and microwave heating (20min at 70, 90, and 120°C) of tomato pulp was evaluated in the absence and in the presence of three different oils (5%) with distinct fatty acid composition (coconut oil, olive oil, and fish oil). Lycopene bioaccessibility in the processed samples was studied by quantifying the fraction of lycopene that was transferred from the food matrix to the aqueous micellar phase during in vitro digestion.Adding lipids prior to processing clearly enhanced the lycopene bioaccessibility. However, the type of lipid added was of minor importance compared to the process conditions applied. HPH or microwave heating of tomato pulp in the presence of lipids during 20min at 70 and 90°C did not improve the lycopene bioaccessibility significantly. When HPH was applied prior to the heat treatment, microwave heating at 90°C could improve the lycopene bioaccessibility. It is hypothesised that HPH damages the cellular barriers for lycopene bioaccessibility, which can be further disrupted by thermal processing improving lycopene release during digestion. Finally, applying conditions of 20min at 120°C as such facilitated the lycopene bioaccessibility remarkably. HPH preceding this thermal treatment was of no extra value in terms of lycopene bioaccessibility.status: publishe

Shelf-life extension of cooked meat products by high hydrostatic pressure treatment combined with natural preservatives

status: publishe

Shelf-life extension of cooked ham model product by high hydrostatic pressure and natural preservatives

The inactivation of different spoilage organisms and surrogate pathogens in a cooked ham model product by high pressure (HP) treatment (100-700 MPa, 5-40 °C, 10 min) was investigated. A 5 log reduction could be achieved at ≥ 600 MPa at ≥ 25 °C. Subsequently, the shelf-life of packaged sliced product was studied during storage (7 °C) after treatment at 600 MPa (10 °C, 10 min) in combination with caprylic acid and Purasal®. Without HP treatment, a plate count of 6 log CFU/g was reached after 40 days, both in presence and absence of antimicrobials. HP treatment delayed this initiation of spoilage to 59 days in absence of antimicrobials. However, microbial growth was completely suppressed during at least 84 days in the HP treated products containing caprylic acid or Purasal®. HP treatment increased drip loss but had no or little effect on colour and sensorial evaluation by a taste panel. However, the antimicrobials had a negative influence on the flavour and aroma at the concentrations used.status: publishe

Novel targeted approach to better understand how natural structural barriers govern carotenoid in vitro bioaccessibility in vegetable-based systems

An experimental approach, allowing us to understand the effect of natural structural barriers (cell walls, chromoplast substructures) on carotenoid bioaccessibility, was developed. Different fractions with different levels of carotenoid bio-encapsulation (carotenoid-enriched oil, chromoplasts, small cell clusters, and large cell clusters) were isolated from different types of carrots and tomatoes. An in vitro method was used to determine carotenoid bioaccessibility. In the present work, a significant decrease in carotenoid in vitro bioaccessibility could be observed with an increasing level of bio-encapsulation. Differences in cell wall material and chromoplast substructure between matrices influenced carotenoid release and inclusion in micelles. For carrots, cell walls and chromoplast substructure were important barriers for carotenoid bioaccessibility while, in tomatoes, the chromoplast substructure represented the most important barrier governing bioaccessibility. The highest increase in carotenoid bioaccessibility, for all matrices, was obtained after transferring carotenoids into the oil phase, a system lacking cell walls and chromoplast substructures that could hamper carotenoid release.publisher: Elsevier articletitle: Novel targeted approach to better understand how natural structural barriers govern carotenoid in vitro bioaccessibility in vegetable-based systems journaltitle: Food Chemistry articlelink: http://dx.doi.org/10.1016/j.foodchem.2013.05.064 content_type: article copyright: Copyright © 2013 Elsevier Ltd. All rights reserved.status: publishe