Amber ale beer enriched with goji berries - The effect on bioactive compound content and sensorial properties.

Goji berries, traditionally used in Chinese medicine, are nowadays gaining popularity in the Western world. Efforts are made to enlarge the offer of goji containing foods. In this study, goji berries were added to ale type beer at different stages of the production process in order to develop a beverage with desirable sensory characteristic and high antioxidant capacity.

A new chemical tool for absinthe producers, quantification of α/β-thujone and the bitter components in Artemisia absinthium.

The concentrations of α/β-thujone and the bitter components of Artemisia absinthium were quantified from alcoholic wormwood extracts during four phenological stages of their harvest period. A solid-phase micro-extraction method coupled to gas chromatography-mass spectrometry was used to determine the concentration of the two isomeric forms of thujone. In parallel, the combination of ultra-high pressure liquid chromatography and high resolution mass spectrometry allowed to quantify the compounds absinthin, artemisetin and dihydro-epi-deoxyarteannuin B.

Quantification of the production of hydrogen peroxide H2O2 during accelerated wine oxidation.

Understanding how wines react towards oxidation is of primary importance. Here, a novel approach was developed based on the quantitative determination of the key intermediate H2O2 produced during accelerated oxidation by ambient oxygen. The assay makes use of the conversion of the non-fluorescent Amplex Red substrate into a fluorescent product in presence of H2O2.

Assessment of photosystem II thermoluminescence as a tool to investigate the effects of dehydration and rehydration on the cyclic/chlororespiratory electron pathways in wheat and barley leaves.

Thermoluminescence emission from wheat leaves was recorded under various controlled drought stress conditions: (i) fast dehydration (few hours) of excised leaves in the dark (ii) slow dehydration (several days) obtained by withholding watering of plants under a day/night cycle (iii) overnight rehydration of the slowly dehydrated plants at a stage of severe dessication. In fast dehydrated leaves, the AG band intensity was unchanged but its position was shifted to lower temperatures, indicating an activation of cyclic and chlororespiratory pathways in darkness, without any increase of their overall electron transfer capacity. By contrast, after a slow dehydration the AG intensity was strongly increased whereas its position was almost unchanged, indicating respectively that the capacity of cyclic pathways was enhanced but that they remained inactivated in darkness.

Pitfalls, artefacts and open questions in chlorophyll thermoluminescence of leaves or algal cells.

Thermoluminescence of intact photosynthetic organisms, leaves or algal cells, raises specific problems. The constitutive S2/3Q B (-) B bands constitute major probes of the state of photosystem II in vivo. The presence of a dark-stable acidic lumen causes a temperature downshift of B bands, specially the S3 B band, providing a lumen pH indicator.