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1.
乌骨鸡黑色素及其研究进展   总被引:4,自引:0,他引:4  
乌骨鸡最显著的特征是其体内含有大量黑色素。乌骨鸡黑色素是一种重要的活性物质,已证明其具有消除自由基、抗氧化、抗诱变、抑制病毒、提高机体免疫力、延缓衰老等多种生理功能。本文综述了国内外对乌骨鸡黑色素的结构特征、理化性质、生理功能、合成过程、沉积分布规律、提取方法等方面的研究进展,以期为今后有关乌鸡黑色素的研究工作提供理论参考。  相似文献   

2.
BACKGROUND: Many people in developing countries are still struggling to emerge from the realm of extreme poverty, where economic improvements tend to benefit a small, affluent group of the population and cause growing inequality in health and nutrition that affects the most vulnerable groups of the population, including women and children. OBJECTIVE: To examine how household and community economic inequality affects nutritional status in women using information on 6,922 nonpregnant women aged 15 to 49 years included in the 2000 Cambodia Demographic and Health Survey. METHODS: Nutritional status is defined with the use of the body-mass index (BMI). BMI less than 18.5 kg/m2 is defined as undernourishment. The household wealth index was calculated from household ownership of durable assets and household characteristics. Community wealth is an average household wealth index at the community level. Household and community economic inequalities were measured by dividing the wealth index into quintiles. The effects of household and community economic inequality were estimated by multilevel analysis. RESULTS: Independently of community economic status and other risk factors, women in the poorest 20% of households are more likely to be undernourished than women in the richest 20% of households (RR = 1.63; p = .008). The results also show variation among communities in the nutritional status of women. Age, occupation, and access to safe sources of drinking water are significantly associated with women's nutritional status. CONCLUSIONS: Improving household income and creating employment opportunities for women, in particular poor women, may be a key to improving the nutritional status of women in Cambodia.  相似文献   

3.
Microbial contamination of table eggs has become an important public health problem. In this study, peroxidase-catalyzed compound (PCC), which is innocuous to humans, was tested for its bactericidal activity on a variety of bacteria on inert carriers and on egg shell surfaces. When inert carriers containing Salmonella choleraesuis, Staphylococcus aureus and Pseudomonas aeruginosa were exposed to PCC, population reductions were within acceptable performance standards for standard and simulated hard water conditions. When evaluated for sporicidal activity, PCC gave no positive carriers in a total of 60 carriers tested for either Bacillus subtilis or Clostridium sporogenes. Enterococcus faecalis and Pseudomonas fluorescens viable cells on egg shell surfaces were determined after dip treatment with deionized distilled water, PCC or chlorine-treated (200 ppm) water for 1, 3 and 5 min and compared with those of a control without dip treatment. All treatments significantly reduced the viable cells (log10 CFU/egg) compared to controls for both strains (p < 0.05). Populations of both strains surviving chlorine and PCC were significantly lower than surviving deionized-distilled water, although PCC gave higher recoveries than chlorine (p < 0.05). Populations exposed to PCC treatment were significantly decreased after 3 and 5 min, respectively (p < 0.05). The results of this study indicate that PCC has potential as a table egg sanitizer that could replace the other egg sanitizers which may be environmentally problematic. Based on the inert carrier studies, PCC may also be an effective disinfectant for egg processing equipment and plastic egg cartons in the presence of hard water or contaminating soil .  相似文献   

4.
Beach monitoring programs aim to decrease swimming-related illnesses resulting from exposure to harmful microbes in recreational waters, while providing maximum beach access. Managers are advised by the U.S. EPA to estimate microbiological water quality based on a 5-day geometric mean of fecal indicator bacteria (FIB) concentrations or on a jurisdiction-specific single-sample maximum; however, most opt instead to apply a default single-sample maximum to ease application. We examined whether re-evaluation of the U.S. EPA ambient water quality criteria (AWQC) and the epidemiological studies on which they are based could increase public beach access without affecting presumed health risk. Single-sample maxima were calculated using historic monitoring data for 50 beaches along coastal Lake Michigan on various temporal and spatial groupings to assess flexibility in the application of the AWQC. No calculation on either scale was as low as the default maximum (235 CFU/100 mL) that managers typically use, indicating that current applications may be more conservative than the outlined AWQC. It was notable that beaches subject to point source FIB contamination had lower variation, highlighting the bias in the standards for these beaches. Until new water quality standards are promulgated, more site-specific application of the AWQC may benefit beach managers by allowing swimmers greater access to beaches. This issue will be an important consideration in addressing the forthcoming beach monitoring standards.  相似文献   

5.
In this study, we evaluated efficacy of alpha-cypermethrin and thiamethoxam on concrete, linen and plastic surfaces, against adults of the larger grain borer, Prostephanus truncatus (Horn) (Coleoptera: Bostrychidae), which is an important pest of stored maize in the tropics. Insect mortality was recorded after 1, 3 and 7 days of exposure. Then, separately for each initial exposure, the surviving individuals were transferred to untreated surfaces and delayed mortality was assessed again 1, 3 and 7 days later. Adult mortality on both insecticide treated linen surface was significantly lower than those on the other surfaces. Regarding delayed mortality, for adults that had been initially exposed for 7 d, complete control was detected 7 d later on plastic and concrete surfaces treated with thiamethoxam, while for alpha-cypermethrin complete mortality was detected only on plastic surface. Overall, there was a noticeable delayed mortality of P. truncatus adults, for all exposures and surfaces, which indicates that even if the insects are removed from the substrate that with either alpha-cypermethrin or thiamethoxam, delayed mortality is more likely to occur than recovery.  相似文献   

6.
Three quarters of the population in Sub Saharan Africa lacks access to modern energy, and relies instead on biomass fuels for cooking and heating. The environment and health implications of the use of biomass fuel has been widely documented in the literature, and has raised the topic of energy access in various policy and development arenas. Still, the impact of energy access on food security at the household level has not been explored in detail; consequently the two sectoral policies remain unaligned. Our aims for this review were to document how lack of access to energy can impact on food security through influence on dietary choices and cooking practices; and how reallocation of household resources from food to energy procurement causes a switch to biomass energy forms of lower grade. We searched the literature for published peer-reviewed articles available through major online publication databases, initially identifying 132 articles but finally reviewing a set of 19 that met our criteria. While most studies suggested that fuelwood scarcity can affect food security through three hypothesised pathways, very few of them provided empirical data to support this argument. Overall, the review found coping measures for woodfuel scarcity to be highly contextual and influenced by geography, household economy and labour availability. Due to the limited number of studies with detailed data, it was not possible to perform a comparative analysis that could support or refute a hypothesis that lack of access to energy can impact on food security. More rigorous studies on this topic are needed which could provide evidence for policy action.  相似文献   

7.
Improved sanitation is considered equally important for public health as is access to improved drinking water. However, the world has been slower to meet the challenge of sanitation provision for the world's poor. We analyze previously cited barriers to sanitation coverage including inadequate investment poor or nonexistent policies, governance, too few resources, gender disparities, and water availability. Analysis includes investigation of correlation between indicators of the mentioned barriers and sanitation coverage, correlations among the indicators themselves, and a geospatial assessment of the potential impacts of sanitation technology on global water resources under six scenarios of sanitation technology choice. The challenges studied were found to be significant barriers to sanitation coverage, but water availability was not a primary obstacle at a global scale. Analysis at a 0.5 degrees grid scale shows, however, that water availability is an important barrier to as many as 46 million people, depending on the sanitation technology selected. The majority of these people are urban dwellers in countries where water quality is already poor and may be further degraded by sewering vast populations. Water quality is especially important because this vulnerable population primarily resides in locations that depend on environmental income associated with fish consumption.  相似文献   

8.
高粱食品:一种古老作物带来新的健康   总被引:1,自引:0,他引:1  
高粱是一种古老的作物初次被驯化于非洲,并在公元前3000年左右推广到了世界各地.高粱是一种抗旱的谷类作物,生长在其它作物无法生存的半干旱气候条件下,在2002年世界高粱产量达到5450万公吨.美国高粱年产量可达1300~1500万公吨左右,其中30%~50%用于出口,在西方国家中用高粱喂养动物已非常普遍,大约世界高粱产量的40%被用于作为非洲和印度等国家人民的食物.在美国对于患有腹乳糜泻疾病无法适应面筋蛋白的人已经用白色食品级的杂交作物生产出运用于无小麦产品作为食用,不能食用小麦或其它谷类作物比如黑麦,大麦,他们提供了些刺激性小的面粉已成为用于制造无小麦食品的原料.当高粱缺乏面筋时,高粱粉便不能生产有黏性和弹性的生面团,因此蛋奶糊配方被用于制造高粱产品,包括面包威化饼干、面条和比萨饼皮,这些原来都是由面粉制成.研究表明,高粱系生产高质量食物,因此种植高梁将被用于改善提高食物质量,最近一些研究表明由于这种古老作物包括含有二十烷醇(policosanols)的多酚复合物和高粱蜡的高抗氧化水平,可能对健康有独特的益处,对于保护心血管的健康至关重要.尤其在把小麦作为主要食物的西方世界,对于给患有腹乳糜泻疾病的人们提供了健康稳定的主食是一个挑战.因此高粱这种古老的作物作为21世纪的主要谷类作物引来了新的兴趣和前途,这是由于(1)它对于患有腹乳糜泻疾病的人是一种富有潜力的主食.(2)保持食物的营养和健康的高抗氧化水平和蜡含量.(3)由于它的抗干旱性和有限供水量的高生产量,2030年预期人口指数增长明显.  相似文献   

9.
Access to large sources of quality water for irrigation is fundamental to the hygienic cultivation of fresh produce. However, due to factors such as contamination of water bodies, access to clean uncontaminated water is fast becoming an ever increasing global challenge. The unavailability of quality source water increases the risk of contamination of fresh produce with human pathogenic microorganisms, which may compromise public health. Over the past few years, there has been a decline in the microbiological quality of surface water and other sources used for irrigation. This is mainly due to upstream fecal contamination. Therefore, the assessment and subsequent suitability of alternative water sources for irrigation such as roof-harvested rainwater should be considered. Contrasting views regarding the quality of roof-harvested rainwater (RHRW) have been published. Pathogens such as Salmonella and Campylobacter species and Listeria monocytogenes have been reported in RHRW. Leafy green vegetables such as cabbage, spinach, and lettuce are produced across a wide range of farming systems from regulated formal (commercial farms) to informal (small-scale and homestead gardens) setups. This review will discuss global water challenges associated with irrigation water, microbial quality of source water for irrigation, crop contamination, and pathogen detection and characterization methodologies.  相似文献   

10.
Recent solar disinfection (SODIS) studies in Bolivia and South Africa have reported compliance rates below 35% resulting in no overall statistically significant benefit associated with disease rates. In this study, we report the results of a 1 year randomized controlled trial investigating the effect of SODIS of drinking water on the incidence of dysentery and nondysentery diarrhea among children of age 6 months to 5 years living in rural communities in Cambodia. We compared 426 children in 375 households using SODIS with 502 children in 407 households with no intervention. Study compliance was greater than 90% with only 5% of children having less than 10 months of follow-up and 2.3% having less than 6 months. Adjusted for water source type, children in the SODIS group had a reduced incidence of dysentery, with an incidence rate ratio (IRR) of 0.50 (95% CI 0.27-0.93, p = 0.029). SODIS also had a protective effect against nondysentery diarrhea, with an IRR of 0.37 (95% CI 0.29-0.48, p < 0.001). This study suggests strongly that SODIS is an effective and culturally acceptable point-of-use water treatment method in the culture of rural Cambodia and may be of benefit among similar communities in neighboring South East Asian countries.  相似文献   

11.
通过对造纸黑液中木素改性,研究开发了一种新颖的缓凝型混凝土高效减水剂,这种减水剂增强效果略低于萘系高效减水剂,但保坍效果明显好于萘系减水剂,用其配制的高性能混凝土的坍落度可达20cm左右,2h内坍落度损失少于4cm,价格仅为萘系减水剂的1/3~1/2,用其配制的混凝土耐久性能较好.  相似文献   

12.
乌骨鸡活性肽组成成分及体外抗氧化活性研究   总被引:3,自引:0,他引:3  
本实验对乌骨鸡活性肽的蛋白质含量、多肽含量、游离氨基酸含量和多肽的分子量分布进行了研究,并通过测定乌骨鸡活性肽对Fenton反应产生的羟自由基、邻苯三酚自氧化产生的超氧阴离子的清除率,考察乌骨鸡活性肽的体外抗氧化能力。乌骨鸡活性肽组成分析表明:活性肽中蛋白质含量为90.53%,其中主要成分为小分子多肽(51.46%)和氨基酸(36.17%)。乌骨鸡活性肽分子量分布的凝胶色谱法测定结果显示其分子量集中在1900Da以下,其中小肽所占相对比例较大。体外抗氧化实验结果表明:乌骨鸡活性肽具有较强的清除羟自由基的能力,其清除率与浓度呈剂量关系;并能明显降低邻苯三酚自氧化速率,抑制率与浓度呈正相关,但与肌肽比较,乌骨鸡活性肽的体外抗氧化能力相对要弱。  相似文献   

13.
Pesticides such as pyrethroids have been frequently found in runoff water from urban areas and the offsite movement is a significant cause for aquatic toxicities in urban streams and estuaries. To better understand the origination of pesticide residues in urban runoff, we investigated the association of pyrethroid residues with loose particles in runoff water from concrete surfaces after treatment with commercial products of bifenthrin and permethrin. In runoff water generated from simulated precipitations after 1 to 89 d exposure under dry outdoor conditions, over 80% of the pesticides was found on particles >0.7 μm for most treatments. The solid-water partitioning coefficient (K(d)) on day 1 was estimated to be 2.4 × 10(3) to 1.1 × 10(5) L/kg for permethrin and bifenthrin on these solids. Except for solid formulations, the pesticide-laden particles likely originated from dust particles preexisting on the concrete before treatment and the disintegration of the surficial concrete matter through weathering. We consequently tested a simple sponge-wipe method to collect and analyze the loose particles on concrete. Concurrent analyses (n = 30) showed an excellent linear correlation between the amount of pesticides transferrable to runoff water and that on the wipe (R(2) = 0.78, slope = 1.13 ± 0.11, P < 0.0001). The fact that the linear relationship has a slope close to 1.0 suggests that this method may be used to predict pesticide residues available for contaminating runoff water before runoff actually occurs. The importance of loose particles should be considered when developing practices to mitigate pesticide runoff contamination from urban residential areas.  相似文献   

14.
The biology of vernix caseosa   总被引:1,自引:0,他引:1  
The biology and physical properties of the uniquely human skin cream 'vernix caseosa' are discussed. This material coats the foetal skin surface during the last trimester of gestation and provides multiple beneficial functions for the foetus and newborn infant. Vernix has a complex structure similar to stratum corneum but lacks lipid lamellae and is more plastic due to the absence of desmosomal constraints. In utero, vernix is made in part by foetal sebaceous glands, interacts with pulmonary surfactant, detaches into the amniotic fluid, and is swallowed by the foetus. At the time of birth, vernix has a remarkably constant water content approximating 80%. Postnatally, vernix is simultaneously a cleanser, a moisturizer, an anti-infective, and an anti-oxidant. Vernix facilitates acid mantle development and supports normal bacterial colonization. Its hydrated cellular structure and unusual lipid composition provide a 'best' solution for the needs of the foetus and newborn, not least of which is the attraction of caregivers. Vernix is an important natural biomaterial of potential interest to cosmetic scientists, and other disciplines involved in product development and therapies targeting the complex interface between the stratum corneum and a changing terrestrial environment.  相似文献   

15.
Multisensory interactions have been shown to affect food and beverage perception. Here we investigated if the colour of a plastic cup can affect the perception and expectation of the mineral water that is served in it. In Experiment 1, the participants were required to evaluate freshness, pleasantness, level of carbonation, and lightness of 3 different kind of mineral water (natural, slightly carbonated and carbonated) using visual analogue scales. The water was served in white, red, and blue plastic cups. In Experiment 2, we investigated the participants’ expectations regarding the water served in the same coloured plastic cups without tasting the liquid. In Experiment 3, we investigated if the participants chose to drink a given kind of water when served in a plastic cup of a specific colour. The results of Experiment 1 showed that people perceived mineral water as more carbonated when contained in a red or blue plastic cup, than when contained in a white cup. In Experiment 2, the participants expected the sparkling water contained in a blue cup to be less carbonated than the same water contained in a red or white cup and the slightly carbonated water more carbonated when served in a white or red cup with respect to the blue cup. Moreover, people expected the water to be fresher when contained in a white cup than in a red cup. In Experiment 3, the participants preferentially chose a white plastic cup to taste still water and blue or red cup to taste slightly sparkling water. These results clearly demonstrate that people’s perceptions, expectations, and choices regarding mineral water are differently modulated by the colour of the container where the liquid is served. The present study has important implications not only for understanding the multisensory interactions affecting beverage perception, but also for marketing and packaging design purposes.  相似文献   

16.
O.S. Fasasi  M.A. Oyarekua 《LWT》2007,40(3):513-519
The effect of germination, fermentation, roasting and defatting on the proximate composition, water absorption capacity (WAC), oil absorption capacity (OAC), foaming capacity (FC), foaming stability (FS), emulsion capacity (EC), emulsion stability (ES), packed bulk density (PBD), least gelation concentration (LGC) and protein solubility (PS) of breadfruit seed flour (BSF) was investigated. WAC, OAC, FC, EC, PBD and LGC obtained are 190-380%; 130.3-200.5%; 2.3-60.4%; 12.4-52.9%; 0.4-0.6 g/ml; 6-12% (w/v) and 200-420%; 176.4-320.6; 4.2-70.8%; 20.2-60.4%; 0.5-0.7 g/ml; 0.5-0.8% (w/v) in the full fat and defatted flours respectively. Foams were more stable in the untreated; least in fermented and roasted samples. Defatting improved the FC, FS and EC; roasting and fermentation reduced EC of full fat BSF; Processing and defatting had no effect on the PBD; roasting and germination increased LGC while defatting and fermentation reduced it. Full fat flours had the lowest PS at pH 4 and the highest at pH 8. Fermented full fat BS flour had the highest PS at pH 5 and 8. Defatted germinated, raw dried and roasted BSF had lowest PS at pH 4; PS of fermented BSF is lowest at pH 3 and highest at pH 2.  相似文献   

17.
Including insect ingredients into familiar food products could be a step in enabling a higher acceptance of insects in Western countries. This study investigates the potential of bakery products containing black soldier fly larvae fat (BSF LF) as an ingredient. Sensory and emotional profiling, WTP, liking and product preference were examined for cakes, cookies, and waffles by a total of 344 respondents. Each bakery product was formulated with 0%, 25% and 50% BSF LF as butter substitute. Results showed that BSF LF can replace 25% of butter in these bakery products without changing the overall food experience and liking. In waffles, the substitution might even be up to 50% without influencing consumer’s acceptance. The attributes related to texture and color were hardly affected indicating that this insect fat provides a similar structure and functionality to bakery products as compared with butter. Future research should explore the use of refined BSF LF to reduce off-flavors perceived in formulations containing a higher percentage of insect fat.  相似文献   

18.
Open landfill dumping areas for municipal wastes in Asian developing countries have recently received particular attention with regard to environmental pollution problems. Because of the uncontrolled burning of solid wastes, elevated contamination by various toxic chemicals including dioxins and related compounds in these dumping sites has been anticipated. In this study, concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and coplanar polychlorinated biphenyls (PCBs) were determined in soils from dumping sites in the Philippines, Cambodia, India, and Vietnam. Residue concentrations of PCDD/Fs and coplanar PCBs in dumping site soils were apparently greater than those in soils collected in agricultural or urban areas far from dumping sites, suggesting that dumping sites are potential sources of PCDD/Fs and related compounds. Observed PCDD/F concentrations in soils from dumping sites in the Philippines and Cambodia were comparable or higher than those reported for dioxin-contaminated locations in the world (e.g., near the municipal waste incinerators and open landfill dumping sites). Homologue profiles of PCDD/Fs in dumping site soils from the Philippines and, to a lesser extent, from Cambodia and India reflected patterns of samples representing typical emissions, while profiles of agricultural or urban soils were similar to those of typical environmental sinks. This result suggests recent formation of PCDD/Fs in dumping site areas and that open dumping sites are a potential source of dioxins in Asian developing countries. Uncontrolled combustions of solid wastes by waste pickers, generation of methane gas, and low-temperature burning can be major factors for the formation of dioxins in dumping sites. Elevated fluxes of PCDD/Fs to soils in dumping sites were encountered in the Philippines, Cambodia, India, and Vietnam-Hanoi, and these levels were higher than those reported for other countries. Considerable loading rates of PCDD/Fs in the dumping sites of these countries were observed, ranging from 20 to 3900 mg/yr (0.12-35 mg TEQ/yr). PCDD/F concentrations in some soil samples from the Philippines, Cambodia, India, and Vietnam-Hanoi exceeded environmental guideline values, suggesting potential health effects on humans and wildlife living near these dumping sites. The estimated intakes of dioxins via soil ingestion and dermal exposure for children were higher than those for adults, suggesting greater risk of dioxin exposure for children in dumping sites. To our knowledge, this is the first comprehensive study on PCDD/Fs contamination in open dumping sites of Asian developing countries. On the basis of the result of this study, we have addressed a new environmental issue that open dumping sites are potential sources of PCDD/Fs and related compounds, and dioxin contamination in dumping sites may become a key environmental problem in developing countries.  相似文献   

19.
Research shows that community socioeconomic status (SES) predicts, based on food service types available, whether a population has access to healthy food. It is not known, however, if a relationship exists between SES and risk for foodborne illness (FBI) at the community level. Geographic information systems (GIS) give researchers the ability to pinpoint health indicators to specific geographic locations and detect resulting environmental gradients. It has been used extensively to characterize the food environment, with respect to access to healthy foods. This research investigated the utility of GIS in determining whether community SES and/or demographics relate to access to safe food, as measured by food service critical health code violations (CHV) as a proxy for risk for FBI. Health inspection records documenting CHV for 10,859 food service facilities collected between 2005 and 2008 in Philadelphia, PA, were accessed. Using an overlay analysis through GIS, CHV were plotted over census tracts of the corresponding area. Census tracts (n = 368) were categorized into quintiles, based on poverty level. Overall, food service facilities in higher poverty areas had a greater number of facilities (with at least one CHV) and had more frequent inspections than facilities in lower poverty areas. The facilities in lower poverty areas, however, had a higher average number of CHV per inspection. Analysis of CHV rates in census tracts with high concentrations of minority populations found Hispanic facilities had more CHV than other demographics, and Hispanic and African American facilities had fewer days between inspections. This research demonstrates the potential for utilization of GIS mapping for tracking risks for FBI. Conversely, it sheds light on the subjective nature of health inspections, and indicates that underlying factors might be affecting inspection frequency and identification of CHV, such that CHV might not be a true proxy for risk for FBI.  相似文献   

20.
2,6‐Di‐tert‐butyl‐hydroxytoluene (BHT, E‐321) is a synthetic phenolic antioxidant which has been widely used as an additive in the food, cosmetic, and plastic industries for the last 70 y. Although it is considered safe for human health at authorized levels, its ubiquitous presence and the controversial toxicological data reported are of great concern for consumers. In recent years, special attention has been paid to these 14 metabolites or degradation products: BHT‐CH2OH, BHT‐CHO, BHT‐COOH, BHT‐Q, BHT‐QM, DBP, BHT‐OH, BHT‐OOH, TBP, BHQ, BHT‐OH(t), BHT‐OH(t)QM, 2‐BHT, and 2‐BHT‐QM. These derived compounds could pose a human health risk from a food safety point of view, but they have been little studied. In this context, this review deals with the occurrence, origin, and fate of BHT in foodstuffs, its biotransformation into metabolites, their toxicological implications, their antioxidant and prooxidant properties, the analytical determination of metabolites in foods, and human dietary exposure. Moreover, noncontrolled additional sources of exposure to BHT and its metabolites are highlighted. These include their carryover from feed to fish, poultry and eggs, their presence in smoke flavorings, their migration from plastic pipelines and packaging to water and food, and their presence in natural environments, from which they can reach the food chain.  相似文献   

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