首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 774 毫秒
1.
The newly introduced and improved products offered customers more premium choices, that plus rapid economic growth and rising demand for high quality and nutritional products among customers, stimulated strong growth in the Mengniu Dairy' s UHT milk products. Building on its existing products, the Group has strived for breakthroughs and it lately launched Deluxe Organic Milk, its first organic milk product.  相似文献   

2.
Previous studies have established that consumers have a significantly higher willingness to pay (WTP) for organic foods over their conventional counterparts. Not fully understood is how consumers view the importance of the required attributes of organic, how confident they are that the organic label reflects these attributes, and how these two factors interact and influence WTP. This study used non-hypothetical auction experiments to examine these issues with a sample of 128 consumers from the general population. Participants first entered their WTP for conventional and organic versions of four different foods selected in different categories (dairy, meat, vegetable) to cover the different possible organic attributes. They were then asked to rate their importance level in, and confidence of, seven required attributes of USDA organic (e.g. no synthetic pesticides, non-GM). The specific goals were to examine the relationship between importance and confidence ratings, and to determine if confidence ratings can be predicted by importance and how confidence in turn influences WTP. For the former, importance ratings for all organic attributes were found to be significantly higher than corresponding confidence ratings. Results from a simultaneous equation system then showed that higher importance ratings significantly increased confidence ratings, while higher confidence increased marginal WTP for all four organic food products. These findings suggest WTP for organic foods is more complex than typically perceived, with it relying heavily on how important consumers see each attribute and their confidence that they are really getting those attributes with their purchases.  相似文献   

3.
Brominated flame retardants – polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs), hexabromocyclododecane (HBCD) and others – have been measured in 11 pooled breast milk samples from 109 first-time mothers in Ireland. Additionally, the study has measured levels of polybrominated dibenzo-p-dioxins and furans (PBDD/Fs), mixed halogenated dioxins (PXCC/Fs) and biphenyls (PXBs), polychlorinated naphthalenes (PCNs) and perfluoroalkylated substances (PFAS) in these samples. The mean sum of 19 PBDEs including BDE-209 was 4.85 ng g?1 fat, which is comparable with that found in other European countries. BDE-47, BDE-153, BDE-209, BDE-99 and BDE-100 were found at the highest concentrations. The only PBBs detected consistently were BB-77, BB-126 and BB-153, with highest concentrations being found for BB-153 (mean = 0.13 ng g?1 fat). The mean sum of HBCD enantiomers was 3.52 ng g?1 fat, with α-HBCD representing over 70% of the total. Of the other brominated flame retardants – tetrabromobisphenol-A (TBBP-A), hexabromobenzene (HBB), decabromodiphenylethane (DBDPE) and bis(2,4,6-tribromophenoxyethane) (BTBPE) – examined, only TBBP-A was detected above the limit of detection (LOD), in two of the 11 pools analysed. All measured PBDF congeners were observed (at 0.02–0.91 pg g?1 fat), but 2,3,7,8-tetrabromo-dibenzodioxin (TeBDD) was the only PBDD detected, with a mean concentration of 0.09 pg g?1 fat. The occurrence of the mixed chlorinated/brominated dibenzodioxins, dibenzofurans and biphenyls, 2-B-3,7,8-CDD, 2,3-B-7,8-CDF, 4-B-2,3,7,8-CDF, PXB 105, PXB 118, PXB 126 and PCB 156 in breast milk in the current study may indicate that levels of these contaminants are increasing in the environment. Polychlorinated naphthalenes were detected in all samples, but not perfluorooctane sulfonate (PFOS) and other PFAS. The pattern of occurrence of these brominated and fluorinated persistent organic pollutants (POPs) in Irish breast milk shows a general relationship to their occurrence in food, as reported in a number of surveillance studies carried out by the Food Safety Authority of Ireland.  相似文献   

4.
Colloidal transport has been shown to enhance the migration of plutonium in groundwater downstream from contaminated sites, but little is known about the adsorption of ??Sr and plutonium onto colloids in the soil solution of natural soils. We sampled soil solutions using suction cups, and separated colloids using ultrafiltration to determine the distribution of 23?Pu and ??Sr between the truly dissolved fraction and the colloidal fraction of the solutions of three Alpine soils contaminated only by global fallout from the nuclear weapon tests. Plutonium was essentially found in the colloidal fraction (>80%) and probably associated with organic matter. A significant amount of colloidal ??Sr was detected in organic-rich soil solutions. Our results suggest that binding to organic colloids in the soil solutions plays a key role with respect to the mobility of plutonium in natural alpine soils and, to a lesser extent, to the mobility of ??Sr.  相似文献   

5.
Organically-certified wild plant foods are rarely addressed in scientific or public discourses on organic food even though 30% of the world’s organically-certified land is dedicated to wild plant gathering. This oversight may leave organic consumers unaware of the market relevance of wild plant foods. The aim of this study was therefore to understand organic consumers’ attitudes, knowledge and purchasing and gathering practices with respect to wild plant foods, and how sociodemographic variables and attitudes can predict knowledge and practices. A purposive sample was drawn from 22 urban and rural food markets across Austria and 497 organic consumers were interviewed using successive freelists and four-point Likert scale questions on attitudes. Data were analysed using exploratory factor analysis and multiple linear regressions. Organic consumers knew a median of nine wild food plants, and reported five as being gathered and one as being purchased. They valued food quality and the responsible harvest of wild food plants, but assigned them a low economic relevance, with some respondents sceptical about their suitability as food. Rural residence, a higher share of organic consumption and a greater emphasis on responsible harvesting predicted knowledge and gathering of a larger number of plant species. These results confirm that organic consumers know, gather and have positive attitudes with respect to wild plant foods, although they are hardly aware about their market relevance. We argue that consumers need to be better informed about the wild origin of food ingredients and the added value of organic certification of wild plant foods.  相似文献   

6.
Recent theoretical studies indicate that reactive organic iodocarbons such as CH2I2 would be extremely effective agents for tropospheric Arctic ozone depletion and that iodine compounds added to a Br2/BrCl mixture have a significantly greater ozone (and mercury) depletion effect than additional Br2 and BrCl molecules. Here we report the first observations of CH2I2, CH2IBr, and CH2ICl in Arctic air, as well as other reactive halocarbons including CHBr3, during spring at Kuujjuarapik, Hudson Bay. The organoiodine compounds were present atthe highest levels yet reported in air. The occurrence of the halocarbons was associated with northwesterly winds from the frozen bay, and, in the case of CHBr3, was anticorrelated with ozone and total gaseous mercury (TGM), suggesting a link between inorganic and organic halogens. The absence of local leads coupled with the extremely short atmospheric lifetime of CH2I2 indicates that production occurred in the surface of the sea-ice/overlying snowpack over the bay. We propose an abiotic mechanism for the production of polyhalogenated iodo- and bromocarbons, via reaction of HOI and/or HOBr with organic material on the quasi-liquid layer above sea-ice/snowpack, and report laboratory data to support this mechanism. CH2I2, CH2IBr, and other organic iodine compounds may therefore be a ubiquitous component of air above sea ice where they will increase the efficiency of bromine-initiated ozone and mercury depletion.  相似文献   

7.
AdvanceinNicotinetoNornicotineConversioninTobaccoSHIHONG_ZHI(ZhengzhouTobaccoResearchInstituteofCNTC,88ErqiRoad,Zhengzhou,China)Keywords:Tobacco;Nicotine;Nornicotine;Conversion;Demethylation;Alkaloid;ConverterAbstract:Nicotinetonornicotineconversionincultivatedtobaccowasreviewedinfouraspects,includingtheeffectonTSNAsformationandflavorquality,geneticcontrolandbiochemicalprocess,conversionfrequencyandtime,andthemethodsforearlyidentificationofnicotineconverterplant.SHIHONG_ZHI:…  相似文献   

8.
Soil microbes are central to many soil processes, but due to the structural complexity of soil organic matter, the accurate quantification of microbial biomass contributions continues to pose a significant analytical challenge. In this study, microbes from a range of soils were cultured such that their molecular profile could be compared to that of soil organic matter and native vegetation. With the use of modern NMR spectroscopy, the contributions from microbial species can be discerned in soil organic matter and quantified. On the basis of these studies, the contributions of microbial biomass to soil organic matter appear to be much higher than the 1-5% reported by other researchers. In some soils, microbial biomass was found to contribute >50% of the extractable soil organic matter fractions and approximately 45% of the humin fraction and accounted for >80% of the soil nitrogen. These findings are significant because organic matter is intimately linked to nutrient release and transport in soils, nitrogen turnover rates, contaminant fate, soil quality, and fertility. Therefore, if in some cases soil organic matter and soil organic nitrogen are predominately of microbial origin, it is likely that this fraction, whether in the form of preserved material or living cells, plays an underestimated role in several soil processes.  相似文献   

9.
Wang  Jun  Li  Wei  Niu  Dandan  Singh  Suren  Lu  Fuping  Liu  Xiaoguang 《Food science and biotechnology》2017,26(3):731-738
Food Science and Biotechnology - α-Glucosidase was immobilized onto an epoxy-activated resin (Eupergit C) to catalyze maltose into isomaltooligosaccharides (IMO), and then the effects of...  相似文献   

10.
Recent studies show that PCB (polychlorinated biphenyl) air concentrations remain surprisingly high in parts of Africa and Asia. These are regions where PCBs were never extensively used, but which are implicated as recipients of obsolete products and wastes containing PCBs and other industrial organic contaminants, such as halogenated flame retardants (HFRs). We hypothesize that there may be different trends in emissions across the globe, whereby emissions of some industrial organic contaminants may be decreasing faster in former use regions (due to emission reductions combined with uncontrolled export), at the expense of regions receiving these substances as obsolete products and wastes. We conclude that the potential for detrimental effects on the environment and human health due to long-range transport by air, water, or wastes should be of equal concern when managing and regulating industrial organic contaminants. This calls for a better integration of life-cycle approaches in the management and regulation of industrial organic contaminants in order to protect environmental and human health on a global scale. Yet, little remains known about the amounts of industrial organic contaminants exported outside former use regions as different types of wastes because of the often illicit nature of these operations.  相似文献   

11.
High X-ray absorption and, therefore, excellent X-ray protection properties are related to heavy chemical elements. Therefore, a composite fiber for X-ray protection applications was developed consisting of an organic cellulose part and an inorganic part. Whereas the preceding part provides the common properties connected to fibers and the latter part ensures the X-ray protection effect. The treatment of this composite fiber along the whole textile chain is presented and the possible usage as a common textile fiber in spinning and knitting processes is impressively demonstrated. Textile properties such as air permeability and abrasion stability are successfully tested. Furthermore, the microscopic structure is characterized by means of optical and scanning electron microscopy. The X-ray protective properties are determined by transmission experiments. The realization of a textile product is shown by production of a glove, where protective properties are impressively shown by 3D X-ray tomography. Altogether, the complete production process of X-ray protective textile products using organic/inorganic composite fibers is introduced. Immanent to the presented material are the broad opportunities for developing textile products for X-ray protective applications in medicine, security technology, or materials analytics.  相似文献   

12.
13.
The first simultaneous measurements and analytical data on atmospheric concentrations of PM(2.5), PM(10), inorganic constituents, carbonaceous species, and their optical properties (aerosol optical depth, AOD; absorption coefficient, b(abs); mass absorption efficiency, σ(abs); and single scattering albedo, SSA) from an urban site (Kanpur) in the Indo-Gangetic Plain are reported here. Significantly high aerosol mass concentration (>100 μg m(-3)) and AOD (> 0.3) are seen as a characteristic feature throughout the sampling period, from October 2008 to April 2009. The temporal variability in the mass fractions of carbonaceous species (EC, OC, and WSOC) is pronounced during October-January when emissions from biomass burning are dominant and OC is a major constituent (~30%) of PM(2.5) mass. The WSOC/OC ratio varies from 0.21 to 0.65, suggesting significant contribution from secondary organic aerosols (SOAs). The mass fraction of SO(4)(2-) in PM(2.5) (Av: 12.5%) exceeds that of NO(3)(-) and NH(4)(+). Aerosol absorption coefficient (@ 678 nm) decreases from 90 Mm(-1) (in December) to 20 Mm(-1) (in April), and a linear regression analysis of the data for b(abs) and EC (n = 54) provides a measure of the mass absorption efficiency of EC (9.6 m(2) g(-1)). In contrast, scattering coefficient (@ 678 nm) increases from 98 Mm(-1) (in January) to 1056 Mm(-1) (in April) and an average mass scattering efficiency of 3.0 ± 0.9 m(2) g(-1) is obtained for PM(10) samples. The highest b(scat) was associated with the dust storm event (April 17, 2009) over northern Iraq, eastern Syria, and southern Turkey; thus, resulting in high SSA (0.93 ± 0.02) during March-April compared to 0.82 ± 0.04 in October-February. These results have implications to large temporal variability in the atmospheric radiative forcing due to aerosols over northern India.  相似文献   

14.
15.
Smallholders’ access to agricultural credit in Pakistan   总被引:1,自引:0,他引:1  
The Government of Pakistan has implemented a policy of food security for smallholders by making provision of credit needed for purchasing inputs such as farm machinery, fertilizer and seed. This study analyzed access to and adequacy of credit for smallholders with landholdings up to 5 acres (= 2 ha), using primary data collected through a survey of 208 households, focus-group discussions and unstructured interviews. The findings revealed a partial success of the national credit policy in terms of the proportion of households having access to formal credit but appeared less successful when this was compared with the total amount of credit demanded and obtained. Among the three types of smallholders compared, i.e. lower-smallholders (≤1.0 acre), middle-smallholders (1.01–2.50 acres) and upper-smallholders (2.51–5.00 acres), the lower-smallholders obtained least benefit from the policy as reflected in the formal credit accounting for 12% of the total credit obtained and only 6% of the total credit demanded. The other two types of smallholders had relatively better access to formal credit. Due to a lack of access to adequate formal credit, informal sources have continued to play a major role in the credit market. The causes for this are explained and relevant policy recommendations are made for improving smallholders’ access to credit in the study area and elsewhere in Pakistan. It is hoped that the findings of this study will make a useful contribution to the understanding and remedying of the difficulties that smallholders experience in obtaining credit which may be of value not only in Pakistan but in other developing countries.  相似文献   

16.
17.
This study aims at relating the survival at 4 °C for 28 days in organic and conventional fermented milks of three strains of Bifidobacterium animalis subsp. lactis (BB12, B94 and BL04), in co-culture with Streptococcus thermophilus TA040 and Lactobacillus bulgaricus LB340, to milk fatty acids profile. Cultivability after 28 days of cold storage was improved in organic fermented milks as compared to conventional products, with slight differences among strains. In addition, the poly-unsaturated fatty acids fraction was higher in organic products, as well as the relative trans-vaccenic (TVA) and α-linolenic (ALA) fatty acids contents that were respectively 1.7 and 2.4 times higher in organic than in conventional fermented milks. From these results, it was concluded that elevated levels of TVA and ALA, together with a lower ratio between linoleic acid and α-linolenic acid, as found in organic products, improved the survival of the bifidobacteria during chilled storage.  相似文献   

18.
The origin of dissolved organic matter (DOM) within sea ice in coastal waters of the Baltic Sea was investigated using parallel factor (PARAFAC) analysis of DOM fluorescence. Sea ice DOM had distinctly different fluorescence characteristics than that of the underlying humic-rich waters and was dominated by protein-like fluorescence signals. PARAFAC analysis identified five fluorescent components, all of which were present in both sea ice and water. Three humic components were negatively correlated to salinity and concluded to be terrestrially derived material. Baltic Sea ice DOM was found to be a mixture of humic material from the underlying water column incorporated during ice formation and autochthonous material produced by organisms within the ice. Dissolved organic carbon (DOC) and nitrogen (DON) concentrations were correlated to the humic fluorescence, indicating that the majority of the organic carbon and nitrogen in Baltic Sea ice is bound in terrestrial humic material trapped within the ice. This has implications for our understanding of sea ice carbon cycling in regions influenced by riverine input (e.g., Baltic and Arctic coastal waters), as the susceptibility of DOM to degradation and remineralization is largely determined by its source.  相似文献   

19.
Indirect (sensitized) photolysis by natural organic matter (NOM), mainly from terrestrial sources, can be an important mechanism for attenuation of organic contaminants in estuarine waters, but the effect of salt gradients has been poorly investigated. We studied Suwannee River NOM-sensitized photolysis of 17β-estradiol (E2) in freshwater and saline media. Indirect photolysis by 4 mg-C/L SRNOM was much faster than direct photolysis, and quenching by sorbic acid verified the importance of triplet-excited NOM chromophores. Increasing halide concentrations up to seawater levels decreased the photolysis rate by 90%, with approximately 70% of this decrease associated with ionic strength effects, and the remainder due to halide-specific effects. Bromide (0.8 mM in seawater) accounted for 70% of the halide-specific effect. Halide promotion of NOM chromophore photobleaching was shown to play a major role in the halide-specific effect. Compared to chromophore bleaching, indirect photolysis of E2 was 230% faster in freshwater, but 63% slower in seawater. The involvement of hydroxyl radical (HO(?)) in indirect photolysis of E2 was ruled out by the lack of suppression by tert-butanol. Experiments in D(2)O-H(2)O demonstrated that (1)O(2) was unimportant in freshwater, but accounted for 42% of NOM-sensitized photolysis of E2 in seawater. We project that, as a parcel of water containing E2 moves through the gradient from freshwater to seawater, overall photolysis will decline due to ionic strength, indirect photolysis will decrease due to specific halide effects on NOM photobleaching, and indirect photolysis will decline relative to direct photolysis. Estuarine contaminant fate models may need to account for halide impacts on indirect photolysis of contaminants.  相似文献   

20.
Gas-particle partitioning theory is widely used in atmospheric models to predict organic aerosol loadings. This theory predicts that secondary organic aerosol (SOA) yield of an oxidized volatile organic compound product will increase as the mass loading of preexisting organic aerosol increases. In a previous work, we showed that the presence of model hydrophobic primary organic aerosol (POA) had no detectable effect on the SOA yields from ozonolysis of α-pinene, suggesting that the condensing SOA compounds form a separate phase from the preexisting POA. However, a substantial faction of atmospheric aerosol is composed of polar, hydrophilic organic compounds. In this work, we investigate the effects of model hydrophilic organic aerosol (OA) species such as fulvic acid, adipic acid, and citric acid on the gas-particle partitioning of SOA from α-pinene ozonolysis. The results show that only citric acid seed significantly enhances the absorption of α-pinene SOA into the particle-phase. The other two seed particles have a negligible effect on the α-pinene SOA yields, suggesting that α-pinene SOA forms a well-mixed organic aerosol phase with citric acid and a separate phase with adipic acid and fulvic acid. This finding highlights the need to improve the thermodynamics treatment of organics in current aerosol models that simply lump all hydrophilic organic species into a single phase, thereby potentially introducing an erroneous sensitivity of SOA mass to emitted OA species.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号