Previously, the metabolism of alpha-tocopherol was considered to involve the opening of the chroman structure because of its oxidation to tocopherylquinone. In contrast, we describe here 2,5,7,8-tetramethyl-2(2'-carboxyethyl)-6-hydroxychroman (alpha-CEHC) as the major urinary metabolite of alpha-tocopherol that appears in human urine after vitamin E supplementation. It is formed directly from alpha-tocopherol without previous oxidative splitting of the chroman ring. The correlation of alpha-tocopherol intake, plasma alpha-tocopherol concentrations, and urinary excretion of alpha-CEHC in human volunteers supplemented with RRR-alpha-tocopherol dosages ranging from 0 to 800 mg/d was examined. HPLC and gas chromatography-mass spectroscopy analysis revealed that alpha-CEHC was only excreted when a plasma threshold of 7-9 mumol alpha-tocopherol/g total lipid was exceeded. This concentration was obtained by a daily intake of approximately 50-150 mg alpha-tocopherol. We suggest that alpha-CEHC excretion indicates a saturated binding capacity of vitamin E in the plasma and thus may be considered to be a marker of optimum vitamin E intake.

About 80% of the world protein production are of vegetable origin. More than half the vegetable protein is fed to animals, whereas merely 10 kg protein per capita are obtained from meat, milk and eggs per year. Therefore, and because of rising prices for raw materials and energy the production and the firsthand utilisation of proteinacous plants for foodstuffs are a worldwide problem. As future source of protein for human nutrition sunflower seed and oil extraction residues from sunflower seed, respectively, are of great significance. Sunflower seed does not contain anti-nutritive and toxical compounds. After crossing of species having a high oil content, the today cultivated sunflower hybrids bring seeds containing 17-22% crude protein and 30-52% oil. The cultivation also has led to a considerable reduction of the hull content. In processing of sunflower proteins colour problems occur resulting from finely ground particles of dark hulls and from polyphenolic acids which are easily oxidized and converted into brown polymerics. Essential components of the sunflower protein production are, therefore, the at least 98% dehulling before processing as well as the separation of polyphenolic acids and/or the prevention of their oxidation. In principle, the variation and combination of technological steps in pre-treating and defatting of sunflower seed, in extracting, precipitating, washing and drying of proteins, the chemical modification of proteins obtained, the interaction with neutral salts or complexing agents, and the admixture of lysine or proteins of high lysine content allow to adapt sunflower proteins to each type of application.

No abstract

Comparing typical examples of equipment for performing the whipping operation, dispersions and colloidal solutions (13 %) respectively of 9 diverse protein based whipping agents were differently aerated, and the foaming properties were determined. Whipping was performed in an industrial manner (batch operation at atmospheric pressure and continuous operation using compressed air and static dispersors) as well as devices widely used in laboratory (household-type mixer and motor-driven plungers moving in ve.rtiCal glass cylinders) were employed. Moreover a new direct current motor-driven whisk/stirrer, the steplessly adjustable rotation speed of which had been made constant and independent of the rheological properties of the protein solutions to be whipped, was tested.Foaming properties measured suggest that only the new laboratory whipping principle reflects the actual performance of protein based whipping agents and that it is far better adapted to large-scale processing then the laboratory equipment most commonly used. Optimum foam forming need distinct rotation speeds and stirring times as well as pH values typical for each product. In creating sugar containing protein foams with a high degree of aeration however in no case of laboratory operational conditions the amount of energy and air available for whipping was sufficiently large. Because of the advantages of the new whipping principle over the othelwise tested ones the motor output and the stirring conditions now are being improved.

Im Unterschied zu der bisher zugrunde gelegten Begriffsbcstimmung (WHO Techn. Rep. Ser. No. 452, Geneva 1970) wird nunmehr erstmalig von zwei Werten des Nihrstokdarfs ausgegangen: dem Grundbedarf (basal requirement) und dem normativen Bevorratungsbedarf (normative storage requirement). Erstercr stellt die Nahrstoffmcngc dar, die klinisch nachweisbare Funktionsbeeintrachtigungen verhindert, und letzterer diejenige. welche Korperreserven gewahrlcistct, die im Bedarfsfall ohne nachfolgende Funktionsstiirungen mobilisiert werdcn konnen. Man ist sich. einig, daD solche Reserven zwar wiinschenswert sind, ihre individuelle Hohe abcr nicht angegeben werden kann. Die bislang ,.empfohlene Aufnahme" (recommended intake) wird durch einen ,.Sicherheitsstandard der Aufnahme" (safe level of intake) ersetzt. Er bedeutet die Nahrstoffzufuhr, die bei nahczu allen gesunden Pcrsonen dic Aufrechterhaltung von Gesundheit und angemessenen Niihrstoffreservcn absichcrt und voii dcr man glaubl, daO sie bei beliebigen Einzelpersonen nur ein sehr geringes Risiko fur cinc Niihrstoffverarmung darstellt. Obgleich in mg/d oder mg/kg pro Tag ausgedriickt, sol1 der Sicherhcitsstandard der Aufnahme die durchschnittliche Zufuhr fur Wochen und Monate und nicht fur jeden einzclnen Tag aufzeigen. Des weiteren sol1 seine Empfehlung nicht die Abkehr von gewohnt hoheren Aufnahmen zur Folge haben, es sei denn, diese bewegen sich in Dimensionen. die bercits rnit einem Intoxikationsrisiko behaftet sind. Die vorgeschlagenen Werte beriicksichtigen. soweit bekannt, Biovcrfiigharkeit, Absorption und Verwertung der Nihrstoffe (so ist z. B. der Bedarf an rnit der Nahrung zugcfuhrtem VitaminA um 10% hoher als der an absorhierbarem). Im cinzelnen werden als Sicherheitsstandard der Aufnahme fur Miinner (65 kg) und Frauen (55 kg) vorgeschlagen: