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排序方式: 共有334条查询结果,搜索用时 31 毫秒
101.
Fungal contamination of food and animal feed, especially by mycotoxigenic fungi, is not only a global food quality concern for food manufacturers, but it also poses serious health concerns because of the production of a variety of mycotoxins, some of which present considerable food safety challenges. In today's mega‐scale food and feed productions, which involve a number of processing steps and the use of a variety of ingredients, fungal contamination is regarded as unavoidable, even good manufacturing practices are followed. Chemical preservatives, to some extent, are successful in retarding microbial growth and achieving considerably longer shelf‐life. However, the increasing demand for clean label products requires manufacturers to find natural alternatives to replace chemically derived ingredients to guarantee the clean label. Lactic acid bacteria (LAB), with the status generally recognized as safe (GRAS), are apprehended as an apt choice to be used as natural preservatives in food and animal feed to control fungal growth and subsequent mycotoxin production. LAB species produce a vast spectrum of antifungal metabolites to inhibit fungal growth; and also have the capacity to adsorb, degrade, or detoxify fungal mycotoxins including ochratoxins, aflatoxins, and Fusarium toxins. The potential of many LAB species to circumvent spoilage associated with fungi has been exploited in a variety of human food and animal feed stuff. This review provides the most recent updates on the ability of LAB to serve as antifungal and anti‐mycotoxigenic agents. In addition, some recent trends of the use of LAB as biopreservative agents against fungal growth and mycotoxin production are highlighted.  相似文献   
102.
In this study, plants belonging to family Solanaceae growing in Western Himalaya region have been observed palynologically under Light Microscope and Scanning electron microscope. Present investigation comprises of 10 genera and 23 species, namely, Atropa acuminata, Capsicum decoraticus, Capsicum frutescens, Cestrum aurantiacum, Cestrum diurnum, Cestrum nocturnum, Datura alba, Datura innoxia, Datura stramonium, Hyoscymus niger, Lycopersicon esculentum, Nicotiana rustica, Nicotiana tabacum, Petunia alba, Petunia hybrida, Solanum erianthum, Solanum melongena, Solanum miniatum, Solanum pseudocapsicum, Solanum surratense, Solanum tuberosum, Withania coagulans, Withania somnifera. Solanaceae is a eurypalynous family. Grains are usually Tricolporate and Tetracolporate, radially symmetrical, isopolar, prolate‐spheroidal to oblate‐spheroidal to oblate‐spheroidal to subprolate to per prolate or suboblate to oblate, size range: 8.55–72 μm, amb circular, semi‐angular or subangular, aperture drop‐type, labrum common‐type, exine usually 2 μm thick, nexine 1–1.5 μm thick. Tectum usually psilate, sexine reticulate, granulate or striato‐reticulate, with obscure pattern, sexine 1–2 μm thick, nexine 1–1.5 μm thick, and intine 0.5–1 μm thick. Most striking variation has been found in the shape class, aperture‐type, and tectal surface. Based on these characters, taxonomic keys have been made for correct identification of members in Solanaceae. However, the grains of this family are usually tricolporate and have direct relationship with certain members of the family Scrophulariaceae. Palyno‐morphological characters of family Solanaceae have been studied for the first time in Western Himalayan region of Pakistan. These palyno‐morphological characters are significant for identification of the members of family Solanaceae.  相似文献   
103.
104.
Hurley T  Sadiq R  Mazumder A 《Water research》2012,46(11):3544-3552
Protecting drinking source water quality is a critical step in ensuring a safe supply of drinking water. Increasingly, drinking source water protection programs rely on the active participation of various stakeholders with differing degrees of water science knowledge. A drinking source water quality index presents a potential communication and analysis tool to facilitate cooperation between diverse interest groups as well as represent composite water quality. We tested the effectiveness of the Canadian Council of Ministers of the Environment Water Quality Index (CCME WQI) in capturing expert assessments of drinking water quality. In cooperation with a panel of drinking water quality experts we identified a core set of parameters to reflect common source water concerns. Drinking source water target values were drafted for use in the index corresponding to two basic treatment levels. Index scores calculated using the core parameter set and associated source water target values were strongly correlated with expert assessments of water quality. We recommend a modified index calculation procedure to accommodate parameters measured at different frequencies within any particular study period. The resulting drinking source water CCME WQI provides a valuable means of monitoring, communicating, and understanding surface source water quality.  相似文献   
105.
Shazia Juna  Anton Huber   《Starch - St?rke》2012,64(3):171-180
The apparent average molar masses (Mw,app), apparent average radii of gyration (Rg,app), of native sago starch and fractions were determined using asymmetrical flow field‐flow fractionation coupled with multi‐angle light scattering and refractive index detectors (AF4/MALS/RI). Amylose‐type (Fraction A) and amylopectin‐type (Fraction B) were chemically separated from native sago starch. Native sago starch and Fractions (A–B) were dissolved in 1M KSCN using a high pressure microwave vessel. The effect of varying cross flow rates at a fixed channel flow rate upon the Mw,app and Rg,app distributions of native sago starch and Fractions (A–B) were investigated. The average Mw,app values of native sago starch, Fraction (A) and Fraction (B) were 60 × 106, 1.5 × 106 and 60 × 106 g/mol, respectively, with average Rg,app values of 142, 75 and 127 nm, respectively. The sphere‐equivalent hydrodynamic radii (Rh) values for native sago starch and fractions were determined from AF4 experimental parameters.  相似文献   
106.
This paper presents a modified unscented Kalman filter for accurate estimation of frequency and harmonic components of a time-varying signal embedded in noise with low signal-to-noise ratio. Further, the model and measurement error covariances along with the unscented Kalman filter parameters are selected using a modified particle swarm optimization algorithm. To circumvent the problem of premature convergence and local minima, a dynamically varying inertia weight based on the variance of the population fitness is used. This results in a better local and global searching ability of the particles, which improves the convergence of the velocity and better accuracy of the unscented Kalman filter parameters. Various simulation results for nonstationary sinusoidal signals with time varying amplitude, phase and harmonic content corrupted with noise, reveal significant improvement in noise rejection and speed of convergence and accuracy in comparison to the well known extended Kalman filter.  相似文献   
107.
The current aim was to evaluate antidiabetic potential of Syzygium aromaticum and Cuminum cyminum essential oils and their emulsions by alpha amylase inhibition assay. Antidiabetic activity of C. cyminum and S. aromaticum was examined in dose dependent mode (1 to 100 µg/mL). The maximum antidiabetic activity for S. aromaticum and C. cyminum essential oils was noted at the highest dose (100 µg/mL). Five emulsions (essential oil + surfactant [tween 80] + co-surfactant [ethanol] + water) of different concentrations for S. aromaticum (A1 to A5) and C. cyminum (B1 to B5) essential oils were formulated. Among different emulsions, A5 of S. aromaticum and B5 of C. cyminum essential oil exhibited a maximum antidiabetic activity with 95.30 and 83.09% inhibition of α-amylase, respectively. Moreover, the analysis of essential oils showed that eugenol (18.7%) and α-pinene (18.8%) were the major components of S. aromaticum and C. cyminum essential oils, respectively.  相似文献   
108.
Food contagion with aflatoxins is the modern concern and has received a great awareness during the last few decades. The intermittent incidence of these toxins in agricultural commodities has negative role on the economy of the affected regions where harvest and postharvest techniques for the prevention of mold growth, are seldom practiced. Aflatoxins are difuranocoumarin derivatives produced by a polyketide pathway by the fungus Aspergillus flavus and Aspergillus parasiticus via polyketide pathway which are highly hepatotoxic, hepatocarcinogenic, teratogenic, and mutagenic in nature and contaminate a wide variety of important agricultural commodities before, during, and after harvest in various environmental conditions. The production of aflatoxins in innate substrates depends upon the various factors, that is, type of substrate, fungal species, moisture contents of the substrate, minerals, humidity, temperature, and physical damage of the kernels. These toxins cause several ailments such as cancer, hepatitis, mutation abnormalities, and reproduction disorders. Minimization and inactivation of aflatoxins contaminants through proper crop management at farm level and with physical, chemical, and biological techniques are the limelight of the article.  相似文献   
109.
Spring wheat varieties were subjected to physico-chemical, mixographic and amino acid analysis. The data obtained was subjected statistically analyzed. The cluster analysis classification based on centroid method indicated that for lysine and overall cookie scores, generally most wheat varieties fell in one group, while for total chapati score most of the wheat varieties were classified into two groups. The wheat varieties falling in same cluster group have similarities in respect of lysine, chapati and cookie quality. This indicated that wheat varieties in Pakistan have narrow ranges of spectrum in their genetic make up for their quality attributes. However, some wheat varieties were distinguished into different groups having a wide distance range especially Shahkar 95 for lysine content, LU 26 and Punjab 96 for cookie quality and Punjnad 88 in case of chapati quality. The present grouping suggests that wheat varieties in cluster group with wider range for lysine content may be used further in a hybridization program to improve the nutritional quality of wheat.  相似文献   
110.
Soil corrosivity is considered to be a major factor for the deterioration of metallic water mains. Using a 10-point scoring method as suggested by the American Water Works Association, soil corrosivity potential can be estimated by five soil properties: (1) resistivity; (2) pH value; (3) redox potential; (4) sulfide; and (5) percentage of clay fines. However, the relationship between soil corrosivity and pipe deterioration is often ambiguous and not well-defined. In order to identify the direct relationship between soil properties and pipe deterioration, which is defined as the ratio of the maximum pit depth to pipe age, predictive data mining approaches are investigated in this study. Both single- and multipredictor based approaches are employed to model such relationship. The advantage of combining multiple predictors is also demonstrated. Among all approaches, rotation forest achieves the best result in terms of the prediction error to estimate pipe deterioration rate. Compared to the random forest method, which is next to the best, the normalized mean square error decreased 50%. With the proposed approaches, the assessment of pipe condition can be achieved by analyzing soil properties. This study also highlights the importance for collecting more reliable soil properties data.  相似文献   
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