In this study the lupine raw materials (flour and hull) of L. luteus var. Juno and L. albus var. Wat were characterized with regard to the dietary fiber content (NDF) and its fractional composition. Functional properties, i.e. water holding capacity (WHC) and cation exchange capacity (CEC) of lupine raw material were determined, with respect to various conditions existing in each part of the human digestive tract (pH-value, time of passage). Experimental products (shortcakes, ginger breads, pancakes, minced meat and dumplings filled with meat) with addition of 5, 10 or 15% of lupine flour or shell were processed and sensory evaluation was performed according to the 5-point scale. The NDF content ranged from 75.7% to 78% in the hull of the Wat and Juno lupine vars. respectively, and 28.8% to 33.4% in the flour. Cellulose was predominant in the hull's NDF while in the flour hemicellulose was major fraction. WHC of samples depended mainly on pH-value and was higher in lupine hulls (up to 5.14 g/g dry matter (d.m.) than in the flours (up to 3.83 g/g d.m.). The CEC of lupine ranged from 0.260 to 0.750 mEq/g d.m. and from 0.330 to 0.870 mEq/g d.m. in flour of the Wat and Juno varieties. The CEC of hull was lower in the Wat var. (0.290 to 0.650 mEq/g d.m.) in comparison with the Juno variety (0.150 to 0.750 mEq/g d.m.) Sensory evaluation showed that 10% addition of flour or hull of lupine to experimental products enables preparation of good quality foodstuffs.

Propanal, butanal, pentanal, and hexanal were stored mixed with cellulose, cellulose impregnated with amino acids, or with proteins at 60 "C and pH = 5.8. Alkanals were partially oxidized, partially aldolized.The corresponding dimers were identified by gas chromatography and mass spectrometry. The aldolizdtion was catalyzed by primary amine groups of amino acids and proteins. Various nonvolatile aldolization and STRECKER degradation products were formed. Aldolization products imparted fruity, sweet and light odour notes to the reaction mixture, accompanied by mushroom, cheese-like and stale notes.

The reaction of ethyl linoleate with collagen proceeded at 60 degrees C following the first order kinetics but during the hydroperoxide decomposition the rate constant of the first order decomposition was substantially lower than that of the second order decomposition. Contrary to cellulose, collagen catalyzed the hydroperoxide decomposition. The amount of total oxidation products rose rapidly at the stage of rapid hydroperoxide formation, and slowly afterwards. The browning reaction was fasted in the stage of maximum hydroperoxide content, and both ether-insoluble and ether-soluble pigments were formed, the latter low in nitrogen. The amount of lipid oligomers increased mainly in the reaction stage following the hydroperoxide maximum. Soluble collagen was converted into insoluble forms by the reaction with oxidized lipids. Basic amino acids were blocked by reaction with oxidized lipids but the bonds formed became resistant to acid hydrolysis only in the stage following the hydroperoxide maximum. Changes of sensory profiles could be explained by reactions of flavour-active carbonylic oxidation products with protein.

Hexanal is rapidly autoxidized in mixture with nonlipidic substrates even at 25 degrees C. The formation of peroxides follows the kinetics of a first order reaction with respect to hexanal (k1 about 10(-5) min-1), and is higher in mixture with casein or lysine-impregnated cellulose than with cellulose. In mixtures containing pure hexanal, peroxides are decomposed more rapidly after second-order reaction with respect to peroxides (k2 about 10(-3) mmol X kg-1 X min-1) while only slowly by the first-order reaction (k3 about 10(-5) min-1). In presence of small amounts of hexanoic acid the rate of second-order peroxide decomposition remained unaffected while the rate of the first-order peroxide decomposition increased by 4 orders (k3 about 10(-1) min-1). The presence of peroxides was percepted in the odour by sensory analysis contrary to nonvolatile lipid hydroperoxides.

A survey has been provided about the possibilities of using the protozoon Tetrahymena in studies on the nutritional value of food proteins. The structure of the protozoon and the elementary requirements regarding its cultivation under laboratory conditions are described. Particular emphasis has been laid on a great many proposals concerning analytical methods. The variability of solutions in this field influences the variability of the results and thus the resulting consequences for research. The presence of technological additives in the investigated food protein reduces the possibility of using the protozoon considerably.