Even when fresh, non-alcoholic, and low-alcoholic beers (NABLABs) exhibit significant staling defects due to premature oxidation. In this study, the antioxidant power of eleven fresh commercial ...NABLABs was assessed by means of three different assays: the oxygen radical absorbance capacity (ORAC), the linoleic acid-induced oxidation (TINH), and the indicator time test (ITT). Only the first two assays, both involving radicalar degradations initiated by AAPH, were found to correlate with each other. NABLABs displayed lower ORAC values than conventional beers (on average, 6127 μmol eq. Trolox/L), except for three samples made with special-colored malts or dry-hopped. Dealcoholization was the step with the greatest impact on the ORAC value (up to a 95% loss) and on flavan-3-ols, sotolon, and polyfunctional thiols, while pasteurization strongly affected color, TBA, and Strecker aldehydes. ORAC assays applied to hop, alternative cereals, and various botanical ingredients indicated that mashing with red sorghum, dry hopping/spicing, and wood maturation could bring the antioxidant power of a NABLAB close to those of conventional beers. With an ORAC value not reached by any other tested botanical ingredient (5234 µmol eq. Trolox/g), African
leaves (traditionally used for Rwandan Ikigage beers) emerged here as the best candidate.
•Successful induction of apple replant disease (ARD) at three different sites.•Non-invasive sensing surveys revealed soil heterogeneity between the sites.•Preliminary soil sensing contributes to ...minimizing unexplained variance within plots.•Growth depressions differed between sites and were highest in the sandy soils.•Bio-tests verify ARD incidence and allow an estimation of ARD severity.
Apple replant disease (ARD) occurs when apple or a closely related species are replanted at the same site leading to severe growth reduction and losses in fruit yield and quality. This complex disease phenomenon is a worldwide problem for tree nurseries and apple orchards. Its causes are not fully understood up to now and economically feasible and sustainable countermeasures do not exist. Research studies to unravel the etiology of ARD are in urgent need of sites differing in soil characteristics with a defined, comparable cropping history including appropriate control (healthy) plots. Thus, the first aim of this study was to induce ARD at three different sites with topsoils covering textures from sand, loamy sand to silt loam (Podzols to Luvisols). Grass plots served as controls. After eight years of repeatedly replanting the apple rootstock ‘Bittenfelder’, growth suppression was observed at the ARD plots on all three sites. Because until now no systematic correlation to soil parameters was approached, the second aim was to study the replant severity in the three different soils. Soil properties were investigated at different spatial scales. Significant differences occurred between sites in soil texture, pH, and C and N contents. Within plots, non-invasive soil sensing (EMI, gamma-spectrometry) helped to ensure homogeneous conditions and to exclude unexplained ARD effects due to small-scale soil heterogeneity. Soil from each site was submitted to a bio-test in which growth of in vitro propagated M26 plantlets in untreated and disinfected soil was compared to determine the ARD severity. Soil disinfection by gamma irradiation resulted in a significant increase in M26 shoot biomass, most pronounced in soil from ARD plots. Thus, on all soils, ARD was successfully induced with a negative correlation between ARD intensity and soil clay content, and a positive correlation with C/N ratio.
Nowadays, non-alcoholic (NAB) and low-alcoholic beers (LAB) still significantly suffer from staling defects when fresh, partially due to absence of ethanol as antioxidant. In the current work, the ...fate of flavan-3-ols (monomers, dimers, and trimers) and bitter compounds (isohumulones, humulinones, etc.) of 11 commercial NABLABs available on the Belgian market was monitored through one year of aging at 20 °C in the dark. Fresh NABLABs contained variable flavan-3-ols and bitter compounds levels (between 3.0–10.0 mg/L and 8.0–39.0 mg/L, respectively), depending on different technological processes used. Chill haze and color were also investigated as potential oxidation markers of fresh and aged beers. Surprisingly, contrary to conventional beers, the oligomers’ concentration (dimer and trimer procyanidins) exhibited a strong correlation (R2 = 0.95) with chill haze before aging, suggesting prematured oxidation of the samples. After a year of storage, significant degradation occurred as for regular dry hopped beers (process very sensitive to oxidation), only 27% remaining for flavan-3-ol dimers and an average 16% for trans-isohumulones. Oxidation risk appears here as the main weakness of NABLABs, which could be probably improved by spiking very efficient antioxidants.
At present, non-alcoholic and low-alcoholic beers (NABLABs), in addition to their premature sensitivity to oxidation, still suffer from a lack of fruity fermentation aromas. ...Maltose/maltotriose-negative yeasts offer a highly attractive alternative for creating diversified pleasant aromas and/or eliminating off-flavors in NABLAB production. The aim of this study was to explore the potential of Saccharomyces cerevisiae var. chevalieri, SafBrewTM LA-01 to release fruity polyfunctional thiols from glutathionylated (G-) and cysteinylated (Cys-) precursors. Interestingly, it proved to release free thiols from their glutathionylated S-conjugate much more efficiently (0.34% from G-3-sulfanylhexanol in 15 °P wort after seven days at 24 °C) than the best S. pastorianus strains previously screened (0.13% for lager yeast L7). On the other hand, despite its classification as a S. cerevisiae strain, it showed an inefficient use of cysteinylated precursors, although the release efficiency was slightly higher under NABLAB fermentation conditions (6 °P; 3 days at 20 °C). Under these conditions, as expected, LA-01 consumed only glucose, fructose, and saccharose (0.4% v/v ethanol formation) and produced only low levels of fermentation esters (1.6 mg/L in total) and dimethylsulfide (5 µg/L). The POF+ character of LA-01 also brought significant levels of 4-vinylguaiacol (810 μg/L), which could give to NABLABs the flavors of a white beer.
Tree roots penetrate the soil to several meters depth, but the role of subsoils for the supply of nutrient elements such as phosphorus (P) to the trees is poorly understood. Here, we tested the ...hypothesis that increased P deficiency in the topsoil results in an increased microbial recycling of P from the forest subsoil. We sampled soils from four German temperate forest sites representing a gradient in total P stocks. We analyzed the oxygen isotopic composition of HClextractable phosphate (δ¹⁸OP) and identified differences in P speciation with increasing soil depth using X-ray absorption near-edge structure (XANES) spectroscopy. We further determined microbial oxygen demand with and without nutrient supply at different soil depths to analyse nutrient limitation of microbial growth and used nanoscale secondary ion mass spectrometry (NanoSIMS) to visualize spatial P gradients in the rhizosphere. We found that d δ¹⁸OP values in the topsoil of all sites were close to the isotopic signal imparted by biological cycling when oxygen isotopes in phosphate are exchanged by enzymatic activity. However, with increasing soil depth and increasing HCl-P concentrations, δ¹⁸O values continuously decreased towards values expected for primary minerals in parent material at depths below 60 cm at sites with high subsoil P stocks and below more than 2 m at sites with low subsoil P stocks, respectively. For these depths, XANES spectra also indicated the presence of apatite. NanoSIMS images showed an enrichment of P in the rhizosphere in the topsoil of a site with high P stocks, while this P enrichment was absent at a site with low P stocks and in both subsoils. Addition of C, N and P alone or in combination revealed that microbial activity in subsoils of sites with low P stocks was mostly P limited, whereas sites with high P stocks indicated N limitation or N and P co-limitation. We conclude that subsoil P resources are recycled by trees and soil microorganisms. With continued weathering of the bedrock and mobilisation of P from the weathered rocks, P cycling will proceed to greater depths, especially at sites characterised by P limitation.
While the Saaz aromatic variety remains classified as a total-flavanoid-rich cultivar, no inverse correlation was found between total flavanoids and the α-acid content when the dual-purpose varieties ...Citra, CTZ, Amarillo, Eureka!, Mandarina Bavaria, Mosaic, Polaris, and Sabro were considered. The levels of hop flavan-3-ol monomers, dimers, and trimers (quantitated by HPLC-MS/MS) appeared strongly influenced by variety and harvest year. On the other hand, the catechin/epicatechin ratio (and B3/B2 ratio) proved stable within the same variety through two successive harvest years. Among the nine herein-investigated varieties, Citra and Saaz displayed notable catechin/epicatechin ratios (>3.7 compared to <1.6 for the others), whereas Polaris exhibited the lowest monomer content (less than 800 mg/kg). These distinctive profiles could impact the colloidal and color stability of hop-forward beers.
Ces 30 dernières années, plusieurs protocoles permettant d’utiliser des données 3D de morphométrie géométrique en cladistique ont été proposés. Fortement critiqués, ces protocoles ne sont ...qu’occasionnellement utilisés en paléoanthropologie, malgré le potentiel évident d’une telle approche. Dans cette étude, nous avons testé deux protocoles différents afin d’évaluer l’information phylogénétique dérivée des données de morphométrie géométrique, que nous avons appliqué à 23 unités taxonomiques opérationnelles (UTOs) représentant les genres Pongo, Gorilla, Pan, Australopithecus et Homo. Ces 23 UTOs sont issues de la moyenne des coordonnées procrustes alignées (analyse procruste généralisée) de trois configurations de points-repères (148, 347 et 636 points-repères) décrivant la morphologie du calvarium de 78 spécimens. Le premier protocole utilise les coordonnées des composantes principales, obtenues après une analyse en composantes principales, comme variables décrivant les UTOs. La seconde approche utilise directement les coordonnées 3D alignées des points-repères. Ces deux ensembles de données ont ensuite été analysés à l’aide des algorithmes "heuristic" et "branch-and-bound" implémentés dans le logiciel TNT. Ces analyses ont produit un arbre cladistique unique pour chaque jeu de données. Indépendamment de la matrice utilisée pour obtenir les arbres, ces résultats préliminaires sont phylogénétiquement cohérents et soutiennent des hypothèses paléoanthropologiques intéressantes.
Over the last 30 years, several protocols to adapt 3D geometric morphometric data to cladistics have been developed. Strongly criticised, these protocols are only occasionally used in palaeoanthropology, despite the obvious heuristic potential of such an approach. This study tests two different protocols to analyse 23 operational taxonomic units (OTUs) representing the genera Pongo, Gorilla, Pan, Australopithecus and Homo, in order to evaluate the phylogenetic information derived from geometric morphometric data. The 23 OTUs were based on averaged Procrustes-aligned coordinates (generalised Procrustes analysis) of three landmark configurations (148, 347 and 636 landmarks) describing the calvarium morphology of 78 specimens. The first protocol used the coordinates of the principal components, obtained after a principal component analysis, as variables describing the OTUs. The second approach directly used the aligned 3D coordinates of the landmarks. These two datasets were then analysed with both the heuristic and branch-and-bound algorithms implemented in the TNT software. These analyses produced a unique cladistic tree for each dataset. Independent of the matrix used to obtain the trees, these preliminary results were phylogenetically consistent and support debated paleoanthropological hypotheses.
Au cours des 30 dernières années, plusieurs protocoles d’intégration de données 3D de morphométrie géométrique en cladistique ont été proposés. Fortement critiqués, ces protocoles ne sont ...qu’occasionnellement utilisés en paléontologie, malgré leur évident potentiel. Dans l’étude proposée ici, nous avons testé deux protocoles différents pour analyser 23 unités taxonomiques opérationnelles (UTO) représentant les genres Pongo, Gorilla, Pan, Australopithecus et Homo, afin de tester les limites de...
•Apple replant disease is reflected in a huge in-field variability of tree growth.•Plants showing most stunted shoot growth revealed lowest δ15N values in the rhizosphere.•Apple replant disease ...severity is correlated to a reduced micronutrient supply of Mn and Co for infected plants up to 100 cm shoot length.
Orchards affected by apple replant disease may show a distinct in-field variability of the severity of apple replant disease (ARD) symptoms. As abiotic soil properties can affect pathogen survival but show considerable variability at the scale of a few meters, we hypothesized that the variability of abiotic soil properties may be used to explain parts of the in-field variability of ARD. We sampled soil and rhizosphere of 32 apple trees with different degree of ARD symptoms after two years of growth at the horticultural research station Heidgraben, Germany. The sandy soils correspond to Entic Podzols. Soil analyses comprised soil aggregate-size fractionations, the assessment of the stocks of nitrogen and essential macro- and micronutrients, as well as a tracing of stable δ15N natural abundance both in rhizosphere and non-rhizosphere soil. The results showed that there was indeed a huge in-field variability of tree growth, following a Gaussian distribution, but classified here in shoot heights of < 40, 40–80, 80–120, and >120 cm, respectively. An effect of soil aggregation on ARD or vice versa was not detected. Elevated tree growth, however, went along with a consumption of soil macronutrients (R2: = 0.3 – 0.8 for the n = 4 ARD classes; significant only for K on individual plant basis). Intriguingly, opposite correlations were observed for micronutrients, where reduced tree growth occurred at subsites short in micronutrient supply (R2 = 0.9 for Mn and Co, significant for Mn and Co for ARD infected plants up to 100 cm shoot length on individual plant basis). Moreover, the plants showing most stunted shoot growth revealed lowest δ15N values in the rhizosphere, as typical for reduced N cycling. Our data therefore confirm that at least parts of the in-field variability of ARD severity is correlated to reduced micronutrient supply and N cycling, possibly via effects on habitat properties of pathogenic soil microbiota.
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