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Common human plasma proteins (CHPP), also called blood proteins, are proteins found in blood plasma. The molecular structure/property-affinity relationships of dietary polyphenols noncovalently binding to CHPP were investigated by comparing the binding constants obtained from the fluorescence titration method. An additional methoxy group in flavonoids increased their binding affinities for CHPP by 1.05 to 72.27 times. The hydroxylation on the 4' position (ring B) of flavones and flavonols and the 5 position (ring A) of isoflavones weakened the binding affinities; however, the hydroxylation on other positions of flavonoids slightly enhanced or little affected the binding affinities for CHPP. The glycosylation of flavonoids weakened or slightly affected the affinities for CHPP by 1 order of magnitude. The hydrogenation of the C2═C3 double bond of flavone, 6-hydroxyflavone, 6-methoxyflavone and myricetin decreased the binding affinities about 10.02 to 17.82 times. The galloylation of catechins significantly improved the binding affinities with CHPP about 10 to 1000 times. The esterification of gallic acid increased its binding affinity. The binding affinities with CHPP were strongly influenced by the structural differences of dietary polyphenols. Polyphenols with higher affinities for purified HSA also showed stronger affinities with CHPP. The hydrophobic force played an important role in binding interaction between polyphenols and CHPP.  相似文献   

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The effect of two sources of Se, selenized yeast (Se-Y) and sodium selenite, added to total mixed rations (TMR) fed to cows on Se milk content and distribution in milk components was studied on three farms for 6 weeks. The maximal increase in milk Se was attained with Se-Y supplemented at 0.3 microg g(-1). The effect was immediate, with an increase of 9 microg L(-1) being observed after only 5 days, and remained steady until the last sample at day 40 of Se supplementation. Se distribution in milk components was constant, 53.6, 42.6, and 9.3% in whey, casein, and fat, respectively, and was unaffected by the form of supplementation. The effect of the level of Se-Y supplementation on milk Se was studied on two farms. Increasing dietary Se-Y from 0 to 0.5 microg g(-1) elevated milk Se content from 20 to 39 microg L(-1). Se-enriched cow's milk at different levels can be produced by varying dietary Se supplementation in the form of selenized yeast.  相似文献   

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BACKGROUND: The effect of depression on dietary intake has not, to our knowledge, been examined in persons with HIV infection. METHODS: We conducted a longitudinal analysis of participants in the Nutrition for Healthy Living Study (NFHL). We measured changes in dietary macronutrient intake in participants who developed depression and, using multiple regression analysis, compared the changes with a control group of patients who did not become depressed. RESULTS: Ninety patients developed depression during the observation period, and we compared these with 152 non-depressed controls. The two groups had similar age and body mass index (BMI) at baseline, but those who developed depression were more likely to be female, less educated and had lower incomes. After adjustment, compared with non-depressed participants, those who developed depression had significantly greater decreases in the following daily intakes: total energy (-341 kcal, P = 0.006), protein (-12.3 g, P = 0.02), total fat (-18.5 g, P = 0.008), carbohydrate (-36.8 g, P = 0.02), total fibre (-4.3 g, P = 0.001) and saturated fat (-6.7 g, P = 0.01). There were no significant differences in the daily intakes of simple sugars and long-chain n-3 fatty acids, or BMI. CONCLUSION: Depression is associated with decreases in total daily energy intake and in six of the eight dietary components we measured. Clinicians should be aware that depression-associated nutritional deficiencies may complicate the care of persons with HIV.  相似文献   

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The health benefits associated with tea consumption have resulted in the wide inclusion of green tea extracts in botanical dietary supplements, which are widely consumed as adjuvants for complementary and alternative medicines. Tea contains polyphenols such as catechins or flavan-3-ols including epicatechin, epigallocatechin, epicatechin gallate, and epigallocatechin gallate (EGCG), as well as the alkaloid, caffeine. Polyphenols are antioxidants, and EGCG, due to its high levels, is widely accepted as the major antioxidant in green tea. Therefore, commercial green tea dietary supplements (GTDS) may be chemically standardized to EGCG levels and/or biologically standardized to antioxidant capacity. However, label claims on GTDS may not correlate with actual phytochemical content or antioxidant capacity nor provide information about the presence and levels of caffeine. In the current study, 19 commonly available GTDS were evaluated for catechin and caffeine content (using high-performance liquid chromatography) and for antioxidative activity [using trolox equivalent antioxidant capacity (TEAC) and oxygen radical antioxidant capacity (ORAC) assays]. Product labels varied in the information provided and were inconsistent with actual phytochemical contents. Only seven of the GTDS studied made label claims of caffeine content, 11 made claims of EGCG content, and five specified total polyphenol content. Caffeine, EGCG, and total polyphenol contents in the GTDS varied from 28 to 183, 12-143, and 14-36% tablet or capsule weight, respectively. TEAC and ORAC values for GTDS ranged from 187 to 15340 and from 166 to 13690 mumol Trolox/g for tablet or capsule, respectively. The antioxidant activities for GTDS determined by TEAC and ORAC were well-correlated with each other and with the total polyphenol content. Reliable labeling information and standardized manufacturing practices, based on both chemical standardization and biological assays, are recommended for the quality control of botanical dietary supplements.  相似文献   

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红薯渣不溶性膳食纤维超高压改性   总被引:4,自引:3,他引:1  
为增强红薯渣膳食纤维的生理功能,研究超高压对其理化性质的影响。该文以红薯渣为原料,采用均匀试验方法对不溶性膳食纤维产品理化性质进行超高压改性,并通过扫描电镜、毛细管电泳法、红外光谱、X射线衍射、比表面积测试法BET和粒度等手段研究改性对膳食纤维结构及理化性质的影响。结果表明:超高压改性不溶性膳食纤维的工艺条件如压力、时间、温度对其调节血糖、血脂、清除外源有害物质能力有显著影响。得出超高压对调节血糖、血脂能力改性条件:600MPa,15min,60℃;清除外源有害物质改性条件:100MPa,10min,42℃。通过对改性膳食纤维结构、理化性质测定发现,改性红薯渣不溶性膳食纤维的微观结构为疏松、光滑、蜂巢形的多孔网状结构;其单糖组分没有太大影响,单糖含量产生了一定程度的变化;改性使结晶度减小,比表面积增大;特征吸收峰增强、红移和蓝移,同时也产生了一些新的吸收峰。研究结果可为红薯渣膳食纤维的功能改性及综合利用提供相关依据。  相似文献   

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OBJECTIVES: To investigate time patterns of compliance with nutrient goals recommended by the World Health Organization (WHO). DESIGN: A single aggregated indicator of distance from the key WHO recommendations for a healthy diet is built using FAOSTAT intake data, bounded between 0 (maximum possible distance from goals) and 1 (perfect adherence). Two hypotheses are tested for different country groupings: (1) whether adherence has improved over time; and (2) whether cross-country disparities in terms of diet healthiness have decreased. SETTING: One hundred and forty-nine countries, including 26 countries belonging to the Organisation for Economic Co-operation and Development (OECD) and 115 developing countries (including 43 least developed countries), with yearly data over the period 1961-2002. RESULTS: The Recommendation Compliance Index (RCI) shows significant improvements in adherence to WHO goals for both developing and especially OECD countries. The latter group of countries show the highest levels of the RCI and the largest increase over time, especially between 1981 and 2002. No improvement is detected for least developed countries. A reduction in disparities (convergence of the RCI) is observed only within the OECD grouping. CONCLUSIONS: Adherence to healthy eating guidelines depends on economic development. Diets are improving and converging in advanced economies, but developing and especially least developed countries are still far from meeting WHO nutrition goals. This confirms findings on the double burden of malnutrition and suggests that economic drivers are more relevant than socio-cultural factors in determining the healthiness of diets.  相似文献   

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OBJECTIVES: To identify and describe dietary patterns in a cohort of pregnant women and investigate whether the dietary patterns are associated with dietary intake and sociodemographic factors. DESIGN: Mothers entering the Finnish Type 1 Diabetes Prediction and Prevention (DIPP) Nutrition Study in 1997-2002 were retrospectively asked to complete a food-frequency questionnaire concerning their diet during pregnancy. Principal components analysis was used to identify dietary patterns. SETTING: Finland. SUBJECTS: Subjects were 3730 women with a newborn infant carrying increased genetic susceptibility to type 1 diabetes mellitus. RESULTS: Seven factors were identified and named. Energy intake correlated positively with 'Healthy', 'Fast food', 'Traditional bread', 'Traditional meat' and 'Coffee' patterns and inversely with the 'Alcohol and butter' pattern. Intake of dietary fibre correlated positively with 'Healthy', 'Traditional bread' and 'Low-fat foods' patterns and inversely with the 'Alcohol and butter' pattern. The seven dietary patterns seemed to account for relatively large proportions of the variance in energy and nutrient intakes except for the intake of vitamin D, vitamin C, carotenoids and calcium. Maternal age and higher level of education were associated with higher scores on 'Healthy', 'Low-fat foods' and 'Alcohol and butter' patterns. CONCLUSION: Principal components analysis produced seven dietary patterns which may be useful for further research concerning maternal diet and health outcomes among both mothers and their offspring.  相似文献   

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Experiments were conducted to evaluate the efficiency of the microalga Nannochloropsis sp. (Nanno.), as a supplement to laying hens' diet, for the production of enriched eggs and meat with omega3 fatty acids (FA). Nanno. has a unique FA composition, namely, the occurrence of a high concentration of eicosapentaenoic acid (EPA; 20:5 omega3) and the absence of other omega3 FA. The effect of supplementing diets with Nanno. on omega3 FA levels in eggs, plasma, liver, and thigh muscle was compared to that of mantur oil, high in alpha-linolenic acid (LNA; 18:3 omega3). Nanno. is rich also in carotenoids, which may be useful for egg yolk pigmentation. The observed effect of Nanno. supplementation on yolk pigmentation was dose responsive, in both the rate of coloration and the color intensity. Addition of enzyme preparations (glucanase plus cellulase or glucanase plus pectinase) slightly elevated the yolk color score. The most prominent changes in the level of omega3 FA in egg yolk were evident when the diets were supplemented with 1% Nanno. or mantur lipid extracts. Levels of dietary algal meal (0.1-1.0%) had low and inconsistent effects on the level of yolk omega3 FA. Algal EPA is not accumulated in the liver or in the egg yolk; it is apparently converted and deposited as docosahexaenoic acid (DHA). LNA from mantur oil was partially converted to DHA, and both DHA and LNA were deposited in egg yolks and livers. It is suggested that the absence of DHA and EPA from thigh muscle is due to the small amount of dietary omega3 FA used in this work, compared to other studies, and to the possibility that in laying hens the egg yolk has a priority on dietary FA over that of muscles.  相似文献   

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Preferences of six collembolans for eight species of microfungi grown in soil have been investigated. Collembolans (Folsomia fimetaria, Isotoma anglicana, Isotama notabilis, Heteromurus nitidus, Protaphorura armata, Pseudosinella alba) and microfungi where chosen for the experiment on the basis of their abundance and vertical distribution in an organically grown field where all organisms and soil were collected. Collembolans were tested with pairs of different species of microfungi and a control (sterile soil) in petri dishes and their position determined after 90 min. Based on the first two axes in a Principal Component Analysis we could identify two main feeding patterns in the collembolans: (1) their general acceptance of the fungi (the mean value of the preference indices for all eight fungi), and (2) their alternating preference for Cladosporium herbarum and Fusarium culmorum (high preference index for C. herbarum and low for F. culmorum or vice versa). The six collembolan species in our study combined these two feeding patterns with an intraspecific preference for the eight fungal species and seemed to minimise food competition among collembolans co-occurring in the same soil horizons. Our data suggest that differences in preference between collembolan species may help to explain the coexistence of many species in the same microhabitats of the soil.  相似文献   

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为明确微波热风联合干燥工艺对枸杞品质和表面微生物数量的影响,检测了微波热风联合干燥和传统热风干燥两种工艺加工各阶段枸杞的主要品质指标(枸杞多糖、总糖、粗蛋白、粗脂肪)和表面微生物数量,并对两种工艺的加工效果进行了比较。结果表明,采用微波热风联合干燥工艺和传统热风干燥工艺加工的枸杞,在枸杞多糖和总糖损失率差异显著(P<0.05),联合干燥工艺较传统工艺分别降低了15.44和11.06个百分点,仅为18.46%和20.98%;在粗蛋白的损失率上差异未达显著水平(P>0.05),损失率分别为21.46%和20.12%;粗脂肪损失率的差异也不显著(P>0.05),分别为10.56%和12.29%。在杀菌率上两种工艺差异显著(P<0.05),联合干燥工艺为91.26%,传统工艺为82.25%。干燥前的脱蜡处理具有杀菌作用,可杀灭65.24%的表面微生物。干燥阶段完成后,联合干燥工艺的杀菌率为91.26%,较传统工艺的杀菌率提高了9.01个百分点。在模拟大肠杆菌污染枸杞的试验中,脱蜡后喷菌的枸杞经两种工艺加工,联合干燥工艺的杀菌率为83.21%,较传统热风干燥工艺提高了12.93个百分点。因此,微波热风联合干燥工艺较传统热风干燥工艺更多地保留了枸杞的营养成分,杀菌效果更好,有利于枸杞干果的品质和食品安全。但是,对脱蜡后大肠杆菌污染的果实,微波热风联合干燥工艺和传统热风干燥工艺均不能彻底灭菌,需进行工艺改进或结合其他灭菌方法进行处理。研究结果为微波热风联合干燥工艺在枸杞加工应用和改进上提供参考。  相似文献   

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OBJECTIVES: To compare dietary diversity scores measured over a 1-day and a 3-day period, and to assess their relationships with socio-economic characteristics and the nutritional status of rural African women. DESIGN: A qualitative dietary recall allowed calculation of a dietary diversity score (DDS; number of food groups consumed out of a total of nine). Body mass index (BMI) and body fat percentage (BFP) were used to assess the nutritional status of women. SETTING AND SUBJECTS: A representative sample of 550 mothers in north-east Burkina Faso. RESULTS: The DDS increased from 3.5 to 4.4 when calculated from a 1-day or a 3-day recall (P < 0.0001), although for the latter the DDS was affected by memory bias. The DDS calculated from a 1-day recall was higher when a market day occurred during the recall period. Both scores were linked to the sociodemographic and economic characteristics of the women. Women in the lowest DDS tertile calculated from the 1-day recall had a mean BMI of 20.5 kg m-(2) and 17.7% of them were underweight, versus 21.6 kg m (-2) and 3.5% for those in the highest tertile (P = 0.0003 and 0.0007, respectively). The DDS calculated from the 1-day recall was also linked to mean BFP; all these links remained significant after adjustment for confounders. For the 3-day period, no such relationships were found to be significant after adjustment. CONCLUSION: The DDS calculated from a 1-day dietary recall was sufficient to predict the women's nutritional status. In such a context attention should be paid to market days.  相似文献   

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