共查询到20条相似文献,搜索用时 93 毫秒
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柿叶茶抗氧化,降血脂保健作用的初步实验 总被引:22,自引:2,他引:20
以鲜嫩棉树叶为原料制成柿叶茶,以45只Wistar大鼠为对象分3组观察饮喂柿叶茶2个月后血清LPO和红细胞SOD及血清甘油三酯的变化。 相似文献
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Y. Pomeranz K. F. Finney R. C. Hoseney 《Journal of the science of food and agriculture》1966,17(11):485-487
Amino-acids were determined in hydrolysates of two wheat varieties harvested at various stages of maturity, and in flours milled from the wheat samples. During maturation, the concentration in protein of lysine, aspartic acid, glycine. alanine and valine decreased; and concentrations of glutamic acid and proline increased. Milling of wheat into flour reduced the concentrations of lysine, arginine, aspartic acid, threonine, glycine and alanine. Concentrations of glutaniic acid and proline were higher in flour than in wheat proteins. Concentrations of cationic side-chains in amino-acids were higher in wheat than in flour, and in both decreased with maturity. Total carboxyl and amide groups were higher in flour than in wheat, and their concentrations increased as the wheat matured. About 84% of the dicarboxylic acids were in amide form. Small changes were observed in concentrations of amino-acid residues with hydroxylic or hydrophobic groups, and in cystine. 相似文献
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R W Welch 《Journal of the science of food and agriculture》1975,26(4):429-435
The fatty acid composition of grain has been studied in six varieties of oats, two of wheat and two of barley, sown in pots in an unheated glasshouse in winter and in spring. Differences were found between the species in composition and in their response to sowing date. Oats showed the greatest varietal variation in both total fatty acid (TFA) content and in the proportion of its component fatty acids. The content and degree of unsaturation of the oat TFA was higher in the winter sown than in the spring sown crop. Increases in the TFA content of oats, whether arising from differences in variety or sowing date, were generally followed by an increase in the proportion of oleic acid and a decrease in the proportions of palmitic and linoleic acid in the TFA. Winter sowing, as compared with spring, led to a small, but significant, decrease in the TFA content of barley and an increase in its degree of unsaturation. There were no significant changes in the content or composition of wheat TFA as a result of differences in sowing date. Factors influencing the differences in TFA content and composition between species, varieties and sowing dates are discussed. 相似文献
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不同生态条件下的烤烟硼营养研究 总被引:11,自引:1,他引:10
在我国7个主产烟省采用"统一栽培法",研究了各生态条件下烤烟营养中硼的积累与分配规律.试验结果表明,烤烟叶片、烟杈(芽)中硼含量明显高于根、茎,其含量以北方高于南方;而根、茎中硼含量正好相反.硼素的积累过程呈明显的Logistic生长曲线关系.大田生长前期南北烟区烟株中硼素积累特征基本一致,但在栽后30 d以后北方烟区烟株中积累量和积累速率远远高于南方烟区.烟株中硼素积累量占全株总积累量的比例为栽后60 d以前南方烟区高于北方烟区,以后则是北方烟区高于南方烟区.在我国南北烟区烟株含硼量(浓度)无明显的差异,但硼积累量差异明显.土壤pH、全氪和速效氮对烟株硼的积累有一定的促进作用,土壤有机质升高则对烟株中硼的积累不利;平均气温、最高温度、10cm地温和日照时数与烟株硼的积累呈正相关. 相似文献
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This study determined the distribution of drugs to different milk fractions according to their physicochemical properties. Hydrophilic drugs tend to concentrate in skim milk, whereas lipophilic drugs tend to concentrate in cream. The concentration of a drug in casein is related to its degree of binding to milk proteins. Thus, we aimed to determine whether withdrawal time in whole milk differs from that in cream, casein, and skim milk. Amoxicillin and tylosin were selected as prototype hydrophilic and lipophilic drugs, respectively. The study was conducted in vitro and in vivo to determine whether in vitro conditions reflect the distribution of drugs in the different milk fractions in vivo. The in vivo study was conducted using a crossover design on 6 healthy Holstein dairy cattle. First, amoxicillin (i.m., single dose, 14 mg/kg) was administered to cows. Following a 1-wk washout period, tylosin (i.m., single dose, 15 mg/kg) was administered. Concentrations of amoxicillin and tylosin in milk and milk fractions were measured using HPLC-UV. In the in vitro study, 0.04 to 400 μg/g of amoxicillin and 0.05 to 50 μg/g of tylosin were spiked to drug-free milk and the concentrations in milk and milk fractions were measured. In addition, the percentage of total protein in milk and milk fractions was determined. Amoxicillin accumulated more in skim milk than in cream and casein, both in vitro (92%) and in vivo (73%, skim milk-to-whole milk ratio). The distribution of tylosin in whole and skim milk was similar to that of amoxicillin in the in vitro study, in contrast to the accumulation of tylosin in cream seen in vivo. However, the accumulation ratio of tylosin in cream was lower than expected. By either method, tylosin was less concentrated in casein than in skim milk and cream. The percentage of total protein was similar in skim milk and whole milk and higher than in cream. Thus, amoxicillin accumulates less in cream and casein, suggesting that these fractions would pose a lower risk to the consumer. Tylosin was still present at the maximum residue limit (50 μg/kg) 24 h after injection in the casein fraction and 48 h after injection in the cream fraction. 相似文献
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Influences of environment and its modification on dairy animal health and production 总被引:10,自引:0,他引:10
R J Collier D K Beede W W Thatcher L A Israel C J Wilcox 《Journal of dairy science》1982,65(11):2213-2227
Physiological state of dairy animals is a predisposing factor in environmental influences on animal health. Critical phases of life cycle include neonatal period, postpubertal reproduction, and lactation. Primary effect of environment in neonatal period is increased disease incidence associated with reduced immunoglobulin content in plasma of calves. Cold stress has little effect on reproduction; in contrast, heat stress reduces libido, fertility, and embryonic survival in cattle. Heat stress in late gestation reduces fetal growth and alters endocrine status of the dam. Carryover effects of heat stress during late gestation on postpartum lactation and reproduction also are detectable. Heat stress of lactating cattle results in dramatic reductions in roughage intake and rumination. Decreases in roughage intake contribute to decreased volatile fatty acid production and may contribute to alteration in ratio of acetate/propionate. Rumen pH also declines during thermal stress. Electrolyte concentrations, in particular sodium and potassium, also are reduced in rumen fluid of heat stressed cattle. The decrease in sodium and potassium are related to increases in loss of urinary sodium and loss of skin potassium as well as decline in plasma aldosterone and increase in plasma prolactin. Reduction in thyroxine, growth hormone, and glucocorticoid concentrations in chronically heat stressed cattle appear to be related to decreases in basal metabolism. 相似文献
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The orientation of fibers is known to play a very important role in determining the quality of the carded and drawn slivers as well as the quality of the ultimate yarns produced from those slivers. Also, the orientation of fibers is considered to be a very useful parameter for evaluating the effectiveness of the carding and drawing processes in aligning the fibers. In addition, the orientation of fibers is known to determine the length utilization of the fibers in the slivers. This article reports on the influence of carding and drawing processes on the orientation of fibers in the carded and drawn slivers. A series of carded and drawn slivers were prepared by using polyester staple fibers and making various changes in the carding and drawing processes and the orientation of fibers in the slivers was evaluated based on Lindsley’s methodology in conjunction with a mathematical model of fiber orientation in slivers. It was observed that the increase in cylinder speed and the decrease in doffer speed resulted in more anisotropic fiber orientation distribution in the carded slivers and the degree of anisotropy was found to be more in the forward direction as compared to the backward direction of the carded slivers. The higher draft and doubling in the drawframe resulted in higher anisotropy in the orientation of fibers in the drawn slivers and the drawn slivers displayed more anisotropy in the backward direction as compared to the forward direction. The higher delivery speed of the drawframe resulted in higher anisotropy in fiber orientation in the drawn slivers and the drawn slivers exhibited more anisotropy in the backward direction as compared to the forward direction. The results of fiber orientation in the carded and drawn slivers obtained by using the mathematical model were compared to the fiber orientation parameters suggested by earlier researchers and a satisfactory correlation between them was observed. 相似文献
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Effect of environmental heat and dietary fiber on thyroid physiology of lactating cows 总被引:7,自引:0,他引:7
Six lactating dairy cows were assigned randomly to a diet either of low fiber (30% corn silage) or of high fiber (70% corn silage). Both groups were subjected to 10 days thermoneutral (17.6 degrees C) and 10 days of environmental heat (31.2 degrees C) to determine effects of dietary fiber content and environmental heat on concentrations of thyroxine and triiodothyronine in plasma, milk, urine, and feces. During heat there were significant reductions in concentrations of thyroxine and triiodothyronine in plasma and in excretion of thyroxine and triiodothyronine in milk. Excretion of thyroxine and triiodothyronine increased in urine during heat stress, whereas concentration and excretion of thyroxine and triiodothyronine in feces decreased. Dietary fiber content had little effect upon thyroxine and triiodothyronine concentrations in plasma or excretion in milk, feces, and urine. Excretion of triiodothyronine in milk was negatively correlated with rectal temperature and positively with content in plasma. The reduction in thyroxine and triiodothyronine of plasma and the decline in excretion of thyroxine and triiodothyronine suggested that environmental heat reduced synthesis of both hormones. 相似文献
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采用高通量测序技术和多元统计方法,对比研究夏秋两季高温大曲生产过程中的真菌群落结构及其演变。结果表明,夏季大曲的主要真菌有14个属,秋季大曲有17个属,且夏季大曲的主要真菌在秋季大曲中均存在;Pichia、Saccharomycopsis和Wickerhamomyces是夏秋两季大曲生产起始的主要真菌,其中Pichia是秋季大曲生产全程的主要真菌类群,Thermoascus是夏季大曲发酵后期的优势真菌类群;秋季大曲生产过程中真菌类群数量更多,而夏季大曲真菌物种分布更均匀;夏秋两季大曲生产过程可分为2个阶段,分别以8d和12d为分界线,秋季大曲生产过程更易受外界条件影响,特别是生产前期。 相似文献
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H. Müller M. Heinrich N. Mielenz S. Reese A. Steiner A. Starke 《Journal of dairy science》2019,102(10):9213-9223
Vascular changes play an important role in the pathogenesis of claw horn disruption lesions in cattle. The aim of the study was to measure arterial blood flow in the hind limbs of German Holstein cows with claw horn disruption lesions. A 10-MHz linear transducer was used to assess blood flow in the interdigital artery in the dorsal pastern region in the hind limbs of 11 non-lame and 33 lame German Holstein cows in which lameness was scored clinically. Qualitative and quantitative blood flow parameters were compared in affected limbs and unaffected contralateral hind limbs in lame cows and in the hind limbs of lame cows and non-lame cows. A pulsed-wave Doppler signal suitable for analysis was obtained in 78 of 88 limbs (33 affected and contralateral limbs, 22 limbs of control cows). Blood flow curve types 1 and 2 were predominant in the hind limbs of lame cows. Vessel diameter, end-diastolic velocity, and blood flow rate were significantly greater in lame cows than in non-lame cows and were numerically greater in moderately lame cows than in mildly lame cows. The differences in the qualitative and quantitative parameters between lame and non-lame cows were most likely caused by inflammation of the pododerm. The role of weight distribution between the paired hind limbs and the existence of claw horn disruption appeared to have an effect on the differences in local circulation in the affected and unaffected contralateral hind limbs in lame cows. 相似文献
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Waldemar Kmiecik Zofia Lisiewska Anna Korus 《European Food Research and Technology》2007,224(5):573-579
The content of ash, P, K, Ca, Mg, Na, Fe, Zn, Mn, Cu, Cr and Ni was determined in four species of brassicas: Brussels sprouts,
broccoli, and green and white cauliflowers. The investigation covered the raw material, the material blanched or cooked before
freezing and frozen products after 12 months of refrigerated storage and prepared for consumption. Frozen products were obtained
by the traditional method of freezing the blanched material or by the modified method of freezing the cooked material. The
processing of vegetables before freezing (washing, grinding, blanching or cooking) caused statistically significant decreases
in most constituents analysed. Blanching did not basically change the content of sodium and calcium; or that of chromium in
both types of cauliflower; copper and nickel in white cauliflower; and nickel and phosphorus in Brussels sprouts. Cooking
in brine, however, caused increases in the content of ash, sodium and calcium in white cauliflower, decreases in the content
of potassium and iron and, in some species, of the remaining constituents. In comparison with the traditional method, a greater
content of most analysed elements was found in frozen products obtained by the modified technology and prepared for consumption.
However, no significant differences were noted in the level of chromium in all the samples; in the level of calcium in broccoli
and green cauliflower; of nickel in broccoli; of nickel, copper and zinc in white cauliflower; and of copper in green cauliflower. 相似文献