Evaluation of white rot decay in phenol-formaldehyde resin treated European beech (Fagus sylvatica L.) LVL by drilling resistance measurements

Improving the properties of laminated veneer lumber (LVL) through wood modification expands its usage as building material, especially for outdoor applications. The outdoor performance of LVL products needs to be tested against different biotic agents, and methods are needed for testing and evaluating their effect on the structural integrity of LVL. In this study, drilling resistance (DR) measurements were used to quantify the effect of fungal decay in phenol-formaldehyde (PF) resin treated European beech (Fagus sylvatica L.) LVL caused by white rot fungi. Material specific peculiarities and their effect on the evaluation method were studied such as the effect of drill bit blunting, moisture content (MC), drilling direction and PF resin content on the DR of PF-modified LVL. The drilling direction in relation to veneer and glue layers had a significant effect on DR and feeding resistance (FR). The PF resin treatment increased the DR. Feeding resistance was found more sensitive to the blunting of the drill bit than DR. The effect of MC on DR and FR was found to be insignificant. The effect of PF resin content on the prediction of mass loss (ML) by DR became prominent only for ML by white rot decay below 10 %. Correlations between DR, ML due to fungal decay and weight percent gain were established and described with a two-factor regression model. The drill bit feed rate of 0.5 m min^?1 and the rotational frequency of 3500 min^?1 as well as the transversal drilling in relation to the veneer (glue) layers were recommended for the assessment of beech LVL treated with PF resin. The DR measurements showed high potential as a fast standard evaluation method for decay and strength loss of LVL products.

     

Wood surface discolouration due to simulated indoor sunlight exposure

Wood surface colour is a very important quality criterion in the utilisation of wood, especially in indoor applications. In this study, an attempt was made to analyse wood surface discolouration due to artificial indoor light irradiation of the most frequently traded wood species in Europe altogether. Sixteen wood species, twelve hardwood and four softwood species, were exposed for 120 hours to a xenon-arc lamp equipped with a 3 mm window glass filter, in order to simulate natural sunlight behind a window glass. Eleven wood species were chosen and further exposed to irradiation for up to 600 hours. Colour measurements were performed by means of a colorimeter device on exposed and non-exposed areas of the samples. Using the CIE-L*a*b* colour measuring system, wood surface discolouration was measured and calculated according to ?L*, ?a*, ?b* and ?E* values. An idea of the different behaviour of these species and how they relate to each other could be given.     

Selective extraction,structural characterisation and antifungal activity assessment of napins from an industrial rapeseed meal

This article reports an extraction–purification of napins from an industrial rapeseed meal and the assessment of their antimicrobial activity against Fusarium langsethiae. The best extraction conditions are observed at pH 2, 12% (w/w) of rapeseed meal after 15 min of extraction in water at room temperature. Under these conditions the extraction is highly selective, allowing a simple purification process (ammonium sulfate precipitation followed by desalting size exclusion chromatography) to get purified napins. These napins possessed significant anti-Fusarium activity (IC₅₀ = 70 μM) and a compact secondary structure rich in α-helix, which may explain this bioactivity.     

Biochemical characterization and process stability of polyphenoloxidase extracted from Victoria grape (Vitis vinifera ssp. Sativa)

Polyphenol oxidase (PPO) was isolated from Victoria grapes (Vitis vinifera ssp. Sativa) grown in South Africa and its biochemical characteristics were studied. Optimum pH and temperature for grape PPO activity were pH 5.0 and T = 25 °C with 10 mM catechol in McIlvaine buffer as substrate. PPO showed activity using the following substances: catechol, 4 methyl catechol, d, l-DOPA, (+) catechin and chlorogenic acid. K_m and V_max values were 52.6 ± 0.00436 mM and 653 ± 24.0 OD_400 nm/min in the case of 10 mM catechol as a substrate. Eight inhibitors were tested in this study and the most effective inhibitors were found to be ascorbic acid, l-cysteine and sodium metabisulfite. Kinetic studies showed that the thermal inactivation of Victoria grape PPO followed first-order kinetics, with an activation energy, E_a = 225 ± 13.5 of kJ/mol. Both in semipurified extract and in grape juice, PPO showed a pronounced high pressure stability.     

Higher nicotine and carbon monoxide levels in menthol cigarette smokers with and without schizophrenia.

This study examined whether smoking menthol cigarettes was associated with increased biochemical measures of smoke intake. Expired carbon monoxide (CO) and serum nicotine and cotinine were measured in 89 smokers with schizophrenia and 53 control smokers immediately after smoking an afternoon cigarette. Serum nicotine levels (27 vs. 22 ng/ml, p = .010), serum cotinine levels (294 vs. 240 ng/ml, p = .041), and expired CO (25 vs. 21 ppm, p = .029) were higher in smokers of menthol compared with nonmenthol cigarettes, with no differences in 3-hydroxycotinine/cotinine ratios between groups when controlling for race. Backward stepwise linear regression models showed that, in addition to having a diagnosis of schizophrenia, smoking menthol cigarettes was a significant predictor of nicotine and cotinine levels. Individuals with schizophrenia or schizoaffective disorder smoked more generic or discount value brands (Basic, Doral, Monarch, USA, Wave, others) compared with control smokers (28% vs. 6%, p = .002) but did not smoke more brands with high nicotine delivery as estimated by the U.S. Federal Trade Commission method. Although rates of mentholated cigarette smoking were not higher in smokers with schizophrenia overall, they were significantly higher in non-Hispanic White people with schizophrenia compared with controls of the same ethnic/racial subgroup (51% vs. 28%, p<.0001). The higher exhaled CO in menthol smokers suggests that the higher nicotine levels are at least partly related to increased intake of smoke from menthol cigarettes, although menthol-mediated inhibition of nicotine metabolism also may be a factor. Menthol is an important cigarette additive that may help explain why some groups have lower quit rates and more smoking-caused disease.     

The effects of various processing conditions on a protein isolate from Lupinus angustifolius

Lupin protein is a promising ingredient in functional foods because of its purported hypocholesterolaemic and hypotensive activities. In this study a lupin protein isolate from Lupinus angustifolius was thermally and mechanically treated and the effects on its protein profile were determined. As a preliminary step, the main protein components of L. angustifolius were identified, using the canonical proteomic approach, including 2D-separation and mass spectrometry and, whenever necessary, also “de novo peptide sequencing”. Most of the main spots were assigned to the major lupin storage proteins: α-conglutin, β-conglutin, γ-conglutin, and δ-conglutin. The protein degradation induced by the different treatments was studied via differential scanning calorimetry (DSC), 2D-electrophoresis, and mass spectrometry, in order to get the fingerprint of the intact peptides after processing. The results indicate that, even after harsh industrial processing, α-, β- and δ-conglutin are still able to release stable peptides, although they are completely or partially degraded, as shown by the 2D protein profiles and the DSC graphs.     

Etablierung eines Frühwarnsystems zur Erkennung lebensmittelbedingter Risiken in Bayern – risikoorientierte Lebensmittelüberwachung weiter gefasst

Recent and past food scandals highlight the urgent need for food safety authorities to anticipate future risks in order to enable improved and proactive response mechanisms. With this goal in mind, the Bavarian Health and Food Safety Authority (LGL) has established an early warning system aimed at early identification of potential health risks and fraudulent practices in the food sector. The early warning approach allows intervention at different stages of risk development. On the one hand, the scanning of a broad area of the food production chain (horizon scanning) may enable prospective risk identification. To this end, relevant factors of influence (drivers) need to be identified, observed and analyzed. On the other hand, the retrospective analysis of case studies may unravel novel cause-effect associations that could be transferred to other products and production technologies, possibly leading to the identification of new drivers (root cause analysis). Additionally, various datasets emanating from food safety authorities, for example data from the European Rapid Alert System for Food and Feed (RASFF) and from Bavarian-wide laboratory analyses and food business inspections, will be closely observed and analyzed. The multidisciplinary character of the LGL has proven to be essential for the realization of the early warning approach, the analysis of inflowing data and implementation of consequences such as food business inspections and sampling for analysis. This article details the objectives and methodical approaches of the project. The acquisition of systematically compiled information as well as its analysis and assessment are comprehensively described. The early warning system presented here has already contributed significantly to the risk-oriented food inspection practiced to date, by integrating novel risk-relevant aspects.