Fusarium head blight is a fungal disease causing yield losses and mycotoxin contamination in wheat and other cereals. Wheat kernels (cultivar Ritmo) were sampled in 2001, 2002, 2003, and 2006 and
...Fusarium-damaged kernels were separated from sound grain based on visual assessment. Subsequently, grain lots containing 0, 20, 40, 60, 80, and 100% of damaged kernels were compiled. Each lot was split and the spectrometric reflectance (wavelengths 350–2500
nm) was measured using subgroup one, while the concentration of the mycotoxin deoxynivalenol (DON) was determined by high-performance liquid chromatography in subgroup two. DON concentrations in batches classified as sound were not significantly different from 0. Estimating DON contents from the percentage of
Fusarium-damaged kernels was impeded by vast variability, resulting in a coefficient of determination of 0.49. Using spectrometric data subjected to partial least square regression allowed estimating DON contents with higher accuracy, in particular at elevated percentages of damaged kernels. The coefficient of determination was 0.84 for the relationship between DON contents estimated based on spectrometric data and the DON contents measured. The intercept of a regression line fitted through a plot of estimated versus measured DON contents was 0.89
±
3.61
mg/kg. Since intercept
+
standard error was larger than the actual legal limit (1.25
mg DON per kg dry grain in the European Union), the spectrometric procedure was still not precise enough to allow a reliable separation of grain samples with DON contents below 1.25
mg/kg from samples with DON contents above the limit. However, spectrometric data also allowed estimating the DON content of the average damaged kernel within a given lot composed of sound and damaged kernels, which is probably the reason for the reduction of the fraction of unexplained variance by 35% compared to the visual approach and illustrates that spectrometric approaches can make a contribution to reducing DON contents of wheat grain.
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•Plant seed mucilages (PSMs) are eco-green and sustainable edible biopolymers.•PSMs techno-functionality is related to their carbohydrate chemical structure.•Several health benefits ...have been ascribed to PSMs fortified food ingestion.•PSMs possess structuring, stabilising, texturing and interfacial features.
The demand for sustainable, eco-green and minimally processed food ingredients of innate technological (structuring, texturising, stabilising) and functional potential is on the growth. Plant seed mucilage (PSM) constitutes a polysaccharide hydrocolloid of particular physicochemical and structure conformational diversity which endows a broad range of functional and health relevant aspects. Many studies have demonstrated the peculiar structuring and stabilising role of crude and fractionated PSM in model and real food matrices. In addition, PSMs intake through the orogastrointestinal route has been associated with several health benefits such as modulation of postprandial glycaemic and insulinaemic response, hyperlipidaemia counteracting, satiety enhancement, regulation of gut microbiota function. This concise review discusses the most recent advancements in the field of PSM extraction and characterisation as well as their exploitation as alternative hydrocolloids for food and nutraceutical industry applications.
Species determination by sequencing and PCR genetic chemotyping, used to determine the toxigenic potential of Fusarium strains, is fundamental for developing preventive strategies in food safety. ...Here we propose and statistically validate a quick protocol for standardizing the procedure of species determination by sequencing of the elongation factor 1-a and multiplex genetic chemotyping using the Tri12 gene, based on fungal growth on Miracloth tissue coupled with microwave extraction. The test was validated on 75 Fusarium culmorum and Fusarium graminearum strains. Key words: Fusarium culmorum, Fusarium graminearum, microwave DNA extraction, EF1-α
Temperature is one of the abiotic factors limiting growth and productivity of plants. In the present work, the effect of low non‐freezing temperature, as inducer of ‘cold acclimation’, was studied in ...poplar. Actively growing plantlets of Populus tremula × Populus tremuloides cv. Muhs 1 were used, and cold treatment consisted in whole plants exposure to 4°C in controlled conditions. Leaves of cold‐treated poplars were shown to be acclimated, as an increase of their freezing tolerance was measured using electrolyte leakage. Chlorophyll fluorescence measurements revealed a decrease in photosystem II efficiency while the pigment contents of leaves did not vary. In contrast, after 1 week of cold exposure, an accumulation of pigments was noted in the stems near the apex of the stressed plants as confirmed by chromatographic analyses. Simultaneously, a rapid accumulation of osmoprotectants, i.e. carbohydrates (measured by spectrometry), and of stress indicators (e.g. putrescine) occurred; changes in protein patterns also arose. Indeed, Western blot studies revealed that the expression of three families of stress‐related proteins, i.e. dehydrins, stress protein 1 and heat‐shock protein 70, was activated or induced by low temperatures. This study complements a previous work on proteomic and individual carbohydrates and provides insight in the ability of poplar plantlets to cold acclimate and to cope with low temperatures by diverse mechanisms (growth cessation, carbohydrate, pigment, polyamine and protein accumulations) related to stress response or involved in acclimation process.
Although diatom taxa have been observed and described for many years using light and electron microscopy, several taxa have called for some clarifications and taxonomic reassessments. This is the ...case for the order Cymbellales D.G. Mann, which is widely represented in freshwater. The phylogenetic relationships among taxa belonging to this order are not always clear because their taxonomic status has been repeatedly revised. In this study, diatom cells were isolated from rivers in Italy, Luxembourg, Portugal and Spain. In total, 21 18S rDNA gene sequences, representing six genera of Cymbellales (Cymbella C. Agardh, Didymosphenia M. Schmidt, Encyonema Kützing, Gomphoneis Cleve, Gomphonema Ehrenberg and Reimeria Kociolek & Stoermer) were determined. These sequences were analyzed along with other known GenBank diatom 18S rDNA gene sequences. The results indicate that the Cymbellaceae Greville and Gomphonemataceae Kützing, especially the genus Gomphonema, are paraphyletic, and that the significance of some of the morphological characteristics traditionally used for classification purposes requires a reassessment. These results also demonstrate the importance of a polyphasic approach combining both morphological and molecular data in attempting to improve the taxonomy and classification system of diatoms.
Twenty managed honey bee colonies, split between 5 apiaries with 4 hives each, were monitored between the summer of 2011 and spring of 2013. Living bees were sampled in July 2011, July 2012, and ...August 2012. Twenty-five, medium-aged bees, free of varroa mites, were pooled per colony and date, to form one sample. Unlike in France and Belgium, Chronic Bee Paralysis Virus (CBPV) has not been found in Luxembourg. Slow Bee Paralysis Virus (SBPV) and Israeli Acute Paralysis Virus (IAPV) levels were below detection limits. Traces of Kashmir Bee Virus (KBV) were amplified. Black Queen Cell Virus (BQCV), Varroa destructor Virus-1 (VDV-1), and SacBrood Virus (SBV) were detected in all samples and are reported from Luxembourg for the first time. Varroa destructor Macula- Like Virus (VdMLV), Deformed Wing Virus (DWV), and Acute Bee Paralysis Virus (ABPV) were detected at all locations, and in most but not all samples. There was a significant increase in VDV-1 and DWV levels within the observation period. A principal component analysis was unable to separate the bees of colonies that survived the following winter from bees that died, based on their virus contents in summer. The number of dead varroa mites found below colonies was elevated in colonies that died in the following winter. Significant positive relationships were found between the log-transformed virus levels of the bees and the log-transformed number of mites found below the colonies per week, for VDV-1 and DWV. Sacbrood virus levels were independent of varroa levels, suggesting a neutral or competitive relationship between this virus and varroa.
► Gastrointestinal digestion altered apple polyphenolic profile and concentrations. ► Chlorogenic acid was the major polyphenol in apples, but not following digestion. ► Degradation and isomerisation ...of chlorogenic acid occurred in intestinal phase. ► Complete flavan-3-ol (procyanidin B2, epicatechin) degradation occurred in intestinal phase. ► Lower amount of polyphenols potentially bioavailable after dialysis.
To assess bioaccessible and dialysable apple polyphenols available for potential uptake by intestinal epithelial cells, an in vitro gastrointestinal (GI) digestion method was developed and main polyphenols investigated by UPLC. Polyphenolic profiles in the gastric medium were similar to those natively occurring in apples; however, bioaccessible polyphenols were at lower concentrations than those in the apples. The polyphenolic profile was altered during intestinal digestion, with a considerable decrease of total polyphenols. Flavan-3-ols were completely unstable in the intestinal medium, owing to their pH sensitivity. In addition, 41–77% of bioaccessible chlorogenic acid, the major abundant hydroxycinnamic acid in apples, was degraded during intestinal digestion, with partial isomerisation to cryptochlorogenic acid and neochlorogenic acid. All polyphenols found in the intestinal medium were dialysable, but were present at lower concentrations, suggesting that dialysable polyphenols can potentially be taken up by the enterocytes. These results highlight that GI digestion may substantially affect native apple-derived polyphenolic patterns and concentrations.
Sequence analysis of the 18S rDNA gene from 93 taxa belonging to the pennate diatoms plus one centric, Cyclotella meneghiniana Kützing, were made using two different alignments (Clustal and secondary ...structure) and two different types of algorithms (neighbour-joining and maximum likelihood). The monophyly of the bacillariacean taxa depends on the type of alignment used for the 18S gene. A secondary structure alignment does not support its monophyly, whereas a Clustal alignment does, but only in the maximum likelihood analysis. The Eunotiales were basal to all other raphid diatoms if a maximum likelihood analysis was used, regardless of the alignment, whereas a neighbour-joining analysis, regardless of the alignment, pulled the Eunotiales inside the raphid diatom sister to one of the bacillariophycean clades in the secondary structure alignment and sister to a monophyletic bacillariophycean clade in the Clustal alignment. The classification of the Bacillariaceae by Krammer & Lange-Bertalot and Round, Crawford & Mann was not supported by the 18S phylogeny. Taxa of the section Lanceolatae Grunow were present in different clades, but sister relationships between well-supported clades were not supported. Multiseriate striae, which are often considered an important feature, were not supported as being clade-defining features. The two groups, A and B of Krammer & Lange-Bertalot in the section Lanceolatae were not supported by the phylogenetic analyses.
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