Uleine and demethoxyaspidospermine from the bark of Plumeria lancifolia     

França OO  Brown RT  Santos CA 《Fitoterapia》2000,71(2):208-210

The isolation of (+)-uleine (1) and (+)-demethoxyaspidospermine (2) from the bark of Plumeria lancifolia is reported along with (1)H- and (13)C-NMR data.  相似文献   

Characterization of protein fractions from Bt-transgenic and non-transgenic maize varieties using perfusion and monolithic RP-HPLC. Maize differentiation by multivariate analysis     

Rodríguez-Nogales JM  Cifuentes A  García MC  Marina ML 《Journal of agricultural and food chemistry》2007,55(10):3835-3842

Protein fractions from transgenic Bt and non-transgenic maize varieties, extracted by the Osborne solvent fraction procedure, were characterized for the first time by perfusion and monolithic RP-HPLC in very short analysis times. Albumins and globulins from different transgenic Bt maizes as well as from their non-transgenic isogenic varieties were eluted in four peaks using perfusion RP-HPLC, whereas prolamins and glutelins were separated in seven peaks. Monolithic RP-HPLC enabled the separation of maize proteins in a large number of peaks showing 6 and 10 main peaks for albumins and globulins, respectively. Prolamins migrated at retention times higher than 5 min as seven peaks, whereas glutelins were separated in three main peaks appearing at retention times higher than 6.0 min. Moreover, chromatograms of the whole protein extracts showed 8 and 11 components for perfusion and monolithic RP-HPLC, respectively. A comparison of the chromatograms of the whole protein extracts relative to transgenic and non-transgenic varieties evidenced quantitative differences on the percentages of area, mainly for peaks 2 and 3 by perfusion RP-HPLC and for peaks 3 and 7 by monolithic RP-HPLC. A discriminant analysis based on these proteic profiles was carried out to classify and predict transgenic Bt maize lines, achieving 100% correct classification using perfusion RP-HPLC.  相似文献   

Correlation of selected constituents with the total antioxidant capacity of coffee beverages: influence of the brewing procedure     

López-Galilea I  De Peña MP  Cid C 《Journal of agricultural and food chemistry》2007,55(15):6110-6117

Relationships between volatile and nonvolatile compounds and the antioxidant capacity of coffee brews prepared from commercial conventional and torrefacto roasted coffees, employing commonly used doses and prepared by four brewing procedures (filter, plunger, mocha, and espresso machine) were assessed. Significant correlations between volatile Maillard reaction products and antioxidant capacity (measured by both 2,2-diphenyl-1-picrylhydrazyl radical and redox potential methods) were not observed. Highly positive correlations between browned compounds and caffeine with both antioxidant capacity parameters were reported. Principal component analysis allowed coffee brews separation according to coffee roasting processes (PC1) and brewing procedures (PC2), showing that in all cases coffee brews from torrefacto roasted coffee were more antioxidant that those extracted from conventional ones; also, coffee brews extracted by an espresso machine were more antioxidant than those extracted by mocha, plunger, and filter machines.  相似文献   

Different sorption behaviors for wine polyphenols in contact with oak wood   总被引：1，自引：0，他引：1  

Barrera-García VD  Gougeon RD  Di Majo D  De Aguirre C  Voilley A  Chassagne D 《Journal of agricultural and food chemistry》2007,55(17):7021-7027

The evolution of polyphenols of enological interest- monomeric anthocyanins, (+)-catechin, (-)-epicatechin, gallic acid, and trans-resveratrol-in the presence of oak wood was investigated in aging-model conditions. Disappearance kinetics showed that, except for gallic acid, all of the wine polyphenols tend to disappear from the model wine in presence of oak wood, to reach an equilibrium after 20 days of contact. At equilibrium, the higher disappearance rates were obtained for monomeric anthocyanins and trans-resveratrol with values of 20 and 50%, respectively. For monomeric anthocyanins, the rate of disappearance seemed to be independent of their nature. In order to evaluate the contribution of sorption to oak wood in the disappearance phenomena, sorption kinetics were determined for trans-resveratrol and malvidin-3-glucoside through the extraction and the quantification of the fraction sorbed to wood. These curves showed that the wood intake of trans-resveratrol and malvidin-3-glucoside followed a two-step behavior, with a higher rate during the first 2 days, likely due to a surface sorption mechanism, and then a slower rate to reach the equilibrium, which could be related to a diffusion mechanism. The comparison of disappeared and sorbed amounts at equilibrium showed that a minor part of the disappeared monomeric anthocyanins were sorbed by wood. In contrast, half of the concentration decrease of trans-resveratrol in wine finds its origin in a sorption mechanism by oak wood. Results in real wine show similar sorption kinetics.  相似文献   

Multivariate analysis for the evaluation of fiber, sugars, and organic acids in commercial presentations of table olives     

López-López A  Jiménez-Araujo A  García-García P  Garrido-Fernández A 《Journal of agricultural and food chemistry》2007,55(26):10803-10811

Table olives constitute an important part of the Mediterranean diet and the diet of many non-olive-producing countries. The aim of this work was to determine the fiber, sugar, and organic acid contents in Spanish commercial presentations of table olives and characterize them by means of a multivariate analysis. The selection of variables was carried out on the basis of a canonical analysis and their classification, according to processing styles and cultivars, through a linear discriminant analysis. Values of dietary fiber in table olives ranged from 2 to 5 g/100 g edible portion (e.p.). Some stuffing materials (almond, hot red pepper, and hazelnut) or the addition of capers produced a significant increase in the total dietary fiber in green olives. Glucose, fructose, and mannitol were usually found in the ranges of 0-55, 0-70, and 0-107 mg/100 g e.p., respectively. Succinic acid was detected only in green and directly brined olives (0-40 mg/100 g e.p.), while lactic and acetic acids were used within the ranges of 0-681 and 5-492.8 mg/100 g e.p., respectively. A multivariate analysis showed that fiber, mannitol, and succinic, lactic, and acetic acids can be used to discriminate between processing styles (95.5% correct assignations) and cultivars (61.20%). Current data can also be used in the evaluation of the dietary value of table olives.  相似文献   

Content of Nutrient and Antinutrient in Edible Flowers of Wild Plants in Mexico     

Sotelo A  López-García S  Basurto-Peña F 《Plant foods for human nutrition (Dordrecht, Netherlands)》2007,62(3):133-138

Nutrient and antinutritional/toxic factors present in some edible flowers consumed in Mexico were determined. The edible flowers were: Agave salmiana, Aloe vera, Arbutus xalapensis, Cucurbita pepo (cultivated), Erythrina americana, Erythrina caribaea, Euphorbia radians benth and Yucca filifera. The nutrient content in the flowers studied is similar to that of the edible leaves and flowers studied mainly in Africa. The moisture content of the flowers varied from 860 to 932 g kg⁻¹. Crude protein (CP) was between 113 to 275 g kg⁻¹ DM, crude fiber, 104 to 177 g kg⁻¹ DM and the nitrogen free extract, between 425 to 667 g kg⁻¹ DM. The highest chemical score (CS) was found in E. americana and A. salmiana; in five samples the limiting amino acid was lysine, and in three of them it was tryptophan. Trypsin inhibitors and hemaglutinnins had a very low concentration. Alkaloids were present in both the Erythrina species and the saponins in A. salmiana and Y. filifera. Cyanogenic glucosides were not found in the studied flowers. The traditional process of preparing these specific flowers before consumption is by cooking them and discarding the broth; in this way the toxic substances are diminished or eliminated. These edible flowers from wild plants consumed in local areas of the country play an important role in the diet of the people at least during the short time of the season where they are blooming.  相似文献   

一般杂质检查     

a倒垃圾了发几个  第一作者  周坤 《勤云标准版测试》2014,34(1)

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四川肉羊产业现状及发展建议   总被引：1，自引：0，他引：1  

周光明  陈天宝  王小强 《四川畜牧兽医》2014,(2):19-20

进品种3个。培育品种有南江黄羊、简州大耳羊、凉山半细毛羊。山羊地方品种或类群有川南黑山羊、川中黑山羊、成都麻羊等;绵羊地方品种或类群有藏绵羊、贾洛绵羊;引进品种有波尔山羊、努比山羊、吐根堡山羊。大多数品种生产性能优良,为全省实施肉羊产业发展提供了种源保证。  相似文献   

拟鲌和梭鲈血清蛋白的电泳研究     

M.И．ДЖaσapoB  杨秋玲 《淡水渔业》1978,(4):43-45

作者应用琼胶电泳法对拟鲌和梭鲈的血清旦白成分进行了研究。研究证明．这两种鱼的血清旦白可分离出6—7个主要区带。几种旦白成分在鱼类不同性周期的各个时期是不恒定的，在产卵时期变化明显。拟鲌和梭鲈血清中几种旦白成分含量的季节变化具有共同规律。  相似文献   

鳜苗种大批量繁育技术和工艺的研究     

卢焱清  何晏开  余幼如  黄树森  周光明  邱建平  周遵贵 《水利渔业》1994,(5)

１９９３年在涨渡湖催产鳜亲鱼７组，产卵率１００％，获卵４５万粒。受精率７７．８％，孵化率８５．７％，获鱼苗３０万尾。经用孵化环道培育成夏花２９．５万尾；环道和产卵池培育成寸片２１．４２万尾。选择１ｋｇ以上的适宜规格鳜亲鱼强化培育是提高怀卵量和卵子质量及提高受精率、孵化率、苗种成活率的重要措施，采用环道流水培育苗种效果较好。开口饵料鱼以鳊最好。  相似文献