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1.
What is the source of ochratoxin A in wine?   总被引:1,自引:0,他引:1  
During a microvinification trial using natural mouldy grapes from a research experimental vineyard, ochratoxin A (OTA) contaminated white wine was obtained. Potential OTA-producing mycobiota of grape samples used in this microvinification process was assessed. Only Aspergillus carbonarius isolates were detected as producers of OTA. Our report is a strong evidence of the contribution of A. carbonarius in the OTA contamination in wine.  相似文献   

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Submarine groundwater discharge (SGD) is a major process operating at the land-sea interface. Quantifying the SGD nutrient loads and the marine/terrestrial controls of this transport is of high importance, especially in oligotrophic seas such as the eastern Mediterranean. The fluxes of nutrients in groundwater discharging from the seafloor at Dor Bay (southeastern Mediterranean) were studied in detail using seepage meters. Our main finding is that the terrestrial, fresh groundwater is the main conveyor of DIN and silica to the coastal water, with loads of 500 and 560 mol/yr, respectively, per 1 m shoreline. Conversely, recirculated seawater is nutrient-poor, and its role is mainly as a dilution agent. The nutrient loads regenerated in the subterranean estuary (sub-bay sediment) are relatively small, consisting mostly of ammonium (24 mol/yr). On the other hand, the subterranean estuary at Dor Bay sequesters as much as 100 mol N/yr per 1 m shoreline, mainly via denitrification processes. These, and observations from other SGD sites, imply that the subterranean estuary at some coastal systems may function more as a sink for nitrogen than a source. This further questions the extent of nutrient contributions to the coastal water by some subterranean estuaries and warrants systematic evaluation of this process in various hydrological and marine trophic conditions.  相似文献   

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Selenium (Se) is an essential trace element that is ubiquitously present in the environment in small concentrations. Essential functions of Se in the human body are manifested through the wide range of proteins, containing selenocysteine as their active center. Such proteins are called selenoproteins which are found in multiple physiological processes like antioxidative defense and the regulation of thyroid hormone functions. Therefore, Se deficiency is known to cause a broad spectrum of physiological impairments, especially in endemic regions with low Se content. Nevertheless, being an essential trace element, Se could exhibit toxic effects, if its intake exceeds tolerable levels. Accordingly, this range between deficiency and overexposure represents optimal Se supply. However, this range was found to be narrower than for any other essential trace element. Together with significantly varying Se concentrations in soil and the presence of specific bioaccumulation factors, this represents a noticeable difficulty in the assessment of Se epidemiological status. While Se is acting in the body through multiple selenoproteins, its intake occurs mainly in form of small organic or inorganic molecular mass species. Thus, Se exposure not only depends on daily intake but also on the respective chemical form, in which it is present. The essential functions of selenium have been known for a long time and its primary forms in different food sources have been described. Nevertheless, analytical capabilities for a comprehensive investigation of Se species and their derivatives have been introduced only in the last decades. A new Se compound was identified in 2010 in the blood and tissues of bluefin tuna. It was called selenoneine (SeN) since it is an isologue of naturally occurring antioxidant ergothioneine (ET), where Se replaces sulfur. In the following years, SeN was identified in a number of edible fish species and attracted attention as a new dietary Se source and potentially strong antioxidant. Studies in populations whose diet largely relies on fish revealed that SeN represents the main non-protein bound Se pool in their blood. First studies, conducted with enriched fish extracts, already demonstrated the high antioxidative potential of SeN and its possible function in the detoxification of methylmercury in fish. Cell culture studies demonstrated, that SeN can utilize the same transporter as ergothioneine, and SeN metabolite was found in human urine. Until recently, studies on SeN properties were severely limited due to the lack of ways to obtain the pure compound. As a predisposition to this work was firstly a successful approach to SeN synthesis in the University of Graz, utilizing genetically modified yeasts. In the current study, by use of HepG2 liver carcinoma cells, it was demonstrated, that SeN does not cause toxic effects up to 100 M concentration in hepatocytes. Uptake experiments showed that SeN is not bioavailable to the used liver cells. In the next part a blood-brain barrier (BBB) model, based on capillary endothelial cells from the porcine brain, was used to describe the possible transfer of SeN into the central nervous system (CNS). The assessment of toxicity markers in these endothelial cells and monitoring of barrier conditions during transfer experiments demonstrated the absence of toxic effects from SeN on the BBB endothelium up to 100 M concentration. Transfer data for SeN showed slow but substantial transfer. A statistically significant increase was observed after 48 hours following SeN incubation from the blood-facing side of the barrier. However, an increase in Se content was clearly visible already after 6 hours of incubation with 1 M of SeN. While the transfer rate of SeN after application of 0.1 M dose was very close to that for 1 M, incubation with 10 M of SeN resulted in a significantly decreased transfer rate. Double-sided application of SeN caused no side-specific transfer of SeN, thus suggesting a passive diffusion mechanism of SeN across the BBB. This data is in accordance with animal studies, where ET accumulation was observed in the rat brain, even though rat BBB does not have the primary ET transporter OCTN1. Investigation of capillary endothelial cell monolayers after incubation with SeN and reference selenium compounds showed no significant increase of intracellular selenium concentration. Speciesspecific Se measurements in medium samples from apical and basolateral compartments, as good as in cell lysates, showed no SeN metabolization. Therefore, it can be concluded that SeN may reach the brain without significant transformation. As the third part of this work, the assessment of SeN antioxidant properties was performed in Caco-2 human colorectal adenocarcinoma cells. Previous studies demonstrated that the intestinal epithelium is able to actively transport SeN from the intestinal lumen to the blood side and accumulate SeN. Further investigation within current work showed a much higher antioxidant potential of SeN compared to ET. The radical scavenging activity after incubation with SeN was close to the one observed for selenite and selenomethionine. However, the SeN effect on the viability of intestinal cells under oxidative conditions was close to the one caused by ET. To answer the question if SeN is able to be used as a dietary Se source and induce the activity of selenoproteins, the activity of glutathione peroxidase (GPx) and the secretion of selenoprotein P (SelenoP) were measured in Caco-2 cells, additionally. As expected, reference selenium compounds selenite and selenomethionine caused efficient induction of GPx activity. In contrast to those SeN had no effect on GPx activity. To examine the possibility of SeN being embedded into the selenoproteome, SelenoP was measured in a culture medium. Even though Caco-2 cells effectively take up SeN in quantities much higher than selenite or selenomethionine, no secretion of SelenoP was observed after SeN incubation. Summarizing, we can conclude that SeN can hardly serve as a Se source for selenoprotein synthesis. However, SeN exhibit strong antioxidative properties, which appear when sulfur in ET is exchanged by Se. Therefore, SeN is of particular interest for research not as part of Se metabolism, but important endemic dietary antioxidant.  相似文献   

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What is the true supply of amino acids for a dairy cow?   总被引:1,自引:0,他引:1  
Improving the prediction of milk protein yield relies on knowledge of both protein supply and requirement. Definition of protein/amino acid supply in ruminants is a challenging task, due to feedstuff variety and variability and to the remodeling of nutrient intake by the rumen microflora. The questions arise, therefore, how and where should we measure the real supply of AA in the dairy cow? This review will follow the downstream flow of AA from duodenum to peripheral tissue delivery, with a glance at the efficiency of transfer into milk protein. Duodenal AA flow comprises rumen undegradable feed, microbial protein, and endogenous secretions. Most attention has been directed toward definition of the first two contributions but the latter fraction can represent as much as 20% of duodenal flow. More information is needed on what factors affect its magnitude and overall impact. Once digested, AA are absorbed into the portal vein. The ratio of portal absorption to small intestinal apparent digestion varies among essential AA, from 0.43 (threonine) to 0.76 (phenylalanine), due to the contributions of preduodenal endogenous secretions to the digestive flow, non-reabsorption of endogenous secretions and gut oxidation of AA. Few data are available on these phenomena in dairy cows but the evidence indicates that they alter the profile of AA available for anabolic purposes. Recent comparisons of estimated duodenal flux and measured portal flux have prompted a revisit of the NRC (2001) approach to estimate AA flows at the duodenum. Changes to the model are proposed that yield predictions that better fit the current knowledge of AA metabolism across the gut. After absorption, AA flow first to the liver where substantial and differential net removal occurs, varying from zero for the branched-chain AA to 50% of portal absorption for phenylalanine. This process alters the pattern of net supply to the mammary gland. Overall, intermediary metabolism of AA between the duodenum and the mammary gland biologically explains the decreased efficiency of the transfer of absorbed AA into milk protein as maximal yield is approached. Therefore, variable, rather than fixed, factors for transfer efficiencies must be incorporated into future predictive models.  相似文献   

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Colorectal cancer (CRC) is one of the most common cause of cancer death. Phytochemicals, especially anthocyanins/anthocyanidins (A/A), have gathered attention of the scientific community owing to their anti-inflammatory, antioxidant, and cancer-inhibitory properties. In this review, we discussed the possible mechanisms whereby A/A exhibit intestinal anticarcinogenic characteristics. Anthocyanins/anthocyanidins inhibit the pro-inflammatory NF-κB pathway, attenuate Wnt signaling and suppress abnormal epithelial cell proliferation. In addition, A/A induce mitochondrial-mediated apoptosis and downregulate Akt/mTOR (mammalian target of rapamycin) pathway. Furthermore, activation of AMP-activated protein kinase (AMPK) and sirtuin 1 (SIRT1) also contributes to the anti-carcinogenic effects of A/A. Finally, downregulation of metalloproteinases (MMPs) by A/A inhibits tumor invasion and metastasis. In conclusion, A/A exert their anti-tumor effects against colorectal carcinogenesis via multiple mechanisms, providing insights into the use of A/A as a natural chemopreventive intervention on major colorectal carcinogenesis.  相似文献   

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Commercial food waste represents a relatively available high-quality feedstock for landfill diversion to biological treatment. A life-cycle assessment was performed for commercial food waste processed through aerobic composting systems of varying complexity, anaerobic digestion, and landfills with and without gas collection and energy recovery, as well as a bioreactor landfill. The functional unit was 1000 kg of food waste plus 550 kg of branches that are used as a bulking agent. For each alternative, global warming potential, NO(x) and SO(2) emissions, and total net energy use were determined. Anaerobic digestion was the most environmentally beneficial treatment option, leading to -395 kg net CO(2)e per functional unit. This result was driven by avoided electricity generation and soil carbon storage from use of the resulting soil amendment. The composting alternatives led to between -148 and -64 kg net CO(2)e, whereas the landfill alternatives led to the emission of -240 to 1100 kg CO(2)e. A traditional landfill with energy recovery was predicted to have lower emissions than any of the composting alternatives when a fertilizer offset was used. There is variation in the results based on uncertainty in the inputs, and the relative rankings of the alternatives are dependent on the soil amendment offset that is used. The use of compost to offset peat has greater emission offsets than the value of compost as a fertilizer.  相似文献   

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The low rate of innovation and high rate of failure of new food products is a cause for concern. Whilst a wide range of product development process factors are known to influence product success and failure, these predictors are based almost exclusively upon investigations into ‘industrial’ rather than food products. In this paper, an analysis of existing models of product development is carried out, a recently developed model for reduced fat food product development is described and implications for best practice in food product development discussed. Market and consumer knowledge and retailer involvement are key success factors in food product development.  相似文献   

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The growth in organic and low-input farming practices is driven by both market demand for high quality, safe food, and European Union policy support, and these types of farming practices are considered in European Union policies for sustainable production, food quality, healthy life, and rural development. However, many constraints to the development of low-input and organic dairy farming supply chains have been identified, including economic, political, and technical constraints. In order for these types of supply chains to develop and provide further benefits to society, innovations are required to improve their sustainability. However, an innovation will only be taken up and result in desirable change if the whole supply chain accepts the innovation. In this paper, Q methodology is used to identify the acceptability of dairy supply chain innovations to low-input and organic supply chain members and consumers in Belgium, Finland, Italy, and the United Kingdom. A strong consensus existed across all respondents on innovations that were deemed as unacceptable. The use of genetically modified and transgenic organisms in the farming system and innovations perceived as conflicting with the naturalness of the production system and products were strongly rejected. Innovations that were strongly liked across all participants in the study were those related to improving animal welfare and improving forage quality to be able to reduce the need for purchased concentrate feeds. Only minor differences existed between countries as to where the priorities lay in terms of innovation acceptability.  相似文献   

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Wine supply in the French market is structured in an intricate system of categories based on origin. There is very little knowledge about consumers understanding of this complex category system and the sensory styles behind these categories. This study investigated how assessors with different level of expertise categorized Beaujolais wines from general to more specific levels of categorization (grape variety, appellation, and “lieu-dit”) in both perceptual (wines) and conceptual (wine labels) conditions. Based on the literature on expertise, we expected a stronger effect in the perceptual condition, in particular for the most specific levels of categorization. For each wine categorization level, three sets of 12 wines were tasted by three panels of 60 assessors: a panel of unfamiliar novices with no much exposure to Beaujolais wines; a panel of familiar novices with regular exposure to Beaujolais wines; and a panel of experts from the Beaujolais. In both perceptual and conceptual conditions, assessors were asked to perform a binary sorting task, followed by a verbalisation task. Data were analysed using DISTATIS. At each level, with a few exceptions, a clearer separation was observed between the two categories in the conceptual condition than in the perceptual condition. Although the experts categorized the labels by grape variety, they did not spontaneously categorize the wines in that way. Finally, we observed a clear expertise effect only in the conceptual condition. This result will be discussed in terms of expertise acquisition and categorization processes.  相似文献   

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Food security and nutrition have become central to the policy agendas of governmental and non-governmental organizations due to their consequences on health and economic development. Changes in consumption patterns in response to price and income changes could impact on nutrient intake with related positive or negative consequences. This article aims to systematically review the elasticity of calories, macronutrients and micronutrients to income in developing and developed countries. We consider a large set of estimates on income elasticity for calories, protein, fat, zinc, iron and vitamin A. This is one of the few reviews that examines the estimates for income elasticity of calories, micronutrients, and micronutrients on a comparative basis. Moreover, we investigate the determinants of the heterogeneity in estimates by means of a rigorous and popular approach of meta-analysis. We found a substantial publication bias, and, in particular, we found that the quality of data is very important as it is able to influence estimates.  相似文献   

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《Journal of dairy science》2022,105(7):6307-6317
The eliminative behaviors of dairy cattle include frequencies and distribution over time and space for defecations and urinations, how the animal responds to cow-related and environmental factors by way of altered patterns of defecation and urination, and how an animal carries out and responds to its own acts of elimination. This review discusses the available literature to first define and describe eliminative behaviors of dairy cattle; what follows is a discussion on what can affect eliminative behaviors and methods for managing them. Information regarding these behaviors is sparse for dairy cattle and is largely centered around frequencies and distributions over the day. Relationships exist between eliminative behaviors and activity levels of the animals and activity levels of the people who manage them, suggesting that types of housing systems play a key role in mainly where and when eliminations occur. It also seems that individual animals vary in their elimination frequencies, in which case it may be interesting to determine what aspects of their individuality contribute to these differences. Although aspects of housing are intended to separate animals from their excreta, stalls or cubicles are not necessarily designed with cattle's natural eliminative behaviors in mind. Refining the timing of management routines and training of animals are some options in the next steps toward managing eliminative behaviors.  相似文献   

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In order to model and analyze the techno-economic feasibility of a whey processing unit for the production of whey protein concentrate (WPC) integrated with processing of lactose, the present study utilized the software SuperPro Designer® for modeling of the processes, including risk analysis and study of reduced pollution impacts. Six models were constructed for the production of WPC and processing of lactose, which were (1) WPC 34, (2) WPC 34 and lactose powder, (3) WPC 34 and hydrous ethanol fuel, (4) WPC 80, (5) WPC 80 and lactose powder, and (6) WPC 80 and hydrous ethanol fuel. The economic evaluation was performed by analysis of the Payback Period (PP), Net Present Value (NPV), Breakeven Point (BP) and Internal Rate of Return (IRR). Probability distributions obtained by fitting of historical data for whey prices and the final products were used to perform the risk analysis, submitted to a Monte Carlo simulation using the @Risk software. The project showed to be feasible due to the elevated IRR and NPV values, coupled with low BP and PP. When evaluating the individual production of ethanol, it was verified that the production cost of this product was superior to the sale price, making independent production of ethanol from lactose present in the whey uneconomical. Plants with production of lactose powder were more economically attractive and also presented greater reduction of Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD). The financial indices suggested greater feasibility of WPC 80 compared to WPC 34.  相似文献   

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