On the viscosity behaviour of field bean protein isolates in dependence on their degree of acetylation.

The increase of apparent viscosity when protein concentration is raised becomes more and more distinctly pronounced with an increasing degree of acetylation and is displaced at lower protein concentrations. Investigations of the influence of temperature on viscosity behaviour are therefore carried out on the basis of comparable initial viscosity. 20 min heat treatment at different temperatures shows that above 40 degrees C the order of magnitude of the temperature-induced increase in viscosity depends decisively on the degree of acetylation.

Effect of spinning and additional cross-linking with dialdehyde starch or aluminum ions on the digestibility and quality of casein-Vicia faba protein isolate mixtures.

Studies were made in adult rats using an isotopic 15N method. Whole egg, wheat, casein and Vicia faba protein isolate served as reference proteins. The diets were isonitrogenous and feed intake was adjusted to the maintenance energy level.

Digestibility and dietary quality of nonacetylated and acetylated Vicia faba proteins in maintenance. Studies on 15N-labelled adult rats.

N digestibility and the dietary quality of a Vicia faba protein isolate as well as of two protein fractions from this isolate, acetylated and nonacetylated, were estimated in 15N-labelled adult rats. For reference, whole egg, casein and wheat were studied. The diets were fed at maintenance energy intake level.

[Field bean protein diet in hypercholesteremia].

The lipid-lowering effects of Vicia faba protein are well-known only from animal experiments. According to these studies Vicia faba protein is the most powerful cholesterol-lowering agents among vegetable proteins. Therefore we examined these effects in a group of patients with hypercholesterolemia (HLP type IIa).

Production, characterization and application of protein isolates from shark. Part 3. Characterization of protein isolates.

The functional and nutritional characterization of two isolates elaborated through cleaning-extraction processes, as well as that of a third isolate obtained by means of a chemical modification (alkaline heat treatment) from one of the former, was carried out. The first two isolates exhibit in general similar properties, are nutritionally comparable with casein and show a fairly high water absorption, having a potentially great value for instance in bakery and meat products and pastes. The modified isolate is essentially different from the isolate used as raw material in many of the characterized parameters, having a high nitrogen solubility index (NSI) by pH 3.

[Physiological nutrition studies of swine for the evaluation of modified proteins. 3. Relationship between the true and apparent N digestibility and amino acid absorption of the small intestines and the parameters of N metabolism].

Modified proteins were tested in absorption investigations with eight pigs with ileocaecal re-entrant cannulae. The apparent digestibility up to the end of the small intestines showed considerable differences between the feed proteins (77-93%). The same differences could be observed with regard to the apparent absorption of amino acids.

[Nutritional and physiological studies of swine for the evaluation of modified proteins. 2. Determination of endogenous N in the contents of the small intestines using the 15N-tracer method].

The endogenous N-quota in the chyme of the small intestines after providing modified proteins was determined with re-entrant cannulae at the end of the ileum in investigations with pigs (35 to 50 kg live weight) with the isotope dilution method. The N-pool of the test animals was labelled with 15N-glycine and 15N-leucine. The TCA-soluble fraction of the blood plasma served as criterion for the labelling level of the N-pool.

[Nutritional physiology studies in pigs on the evaluation of modified proteins. 1. Results of the estimation of N-turnover, apparent and true digestibility of proteins in addition to apparent and true absorption of amino acids in the entire digestive tract].

Sulfuric acid-casein (A), spray dried isolated Vicia faba protein (B), Vicia faba protein/casein (1 : 1) protein fibres-untreated (C), treated with dialdehyde starch (D) or aluminum chloride (E) and meal of Vicia faba (F) were studied as sole protein sources in semisynthetic feed mixtures on 13 female pigs (40 to 45 kg body weight). Total utilization of nitrogen (b-value, PNu) and intermediate utilization (BW) were highest in A, followed by C. Protein C was superior to D.

Actual problems of research in food science.

Starting from the necessary trend towards development in the field of food production, the author outlines, on the basis of current knowledge, the problems to be solved in food science. A general research conception is deduced for the essential nutrient "protein" (as an example) which is illustrated by results from studies on protein fibre and protein gel formation.

[Nutritional-physiological studies on acetylated fractions of protein from Vicia faba].

The nutritional-physiological value of an easily soluble and of a difficulty soluble fraction of protein from Vicia faba (showing a degree of acetylation of 0%, 43% and 94%, respectively) was characterized by determining the amino-acid content, the enzymatic amino-acid availability and the nitrogen balance in the rat. The results from both the amino-acid analysis and the animal experiments on the biological value evidenced that the nutritional-physiological value of the easily soluble fraction of protein from Vicia faba is significantly lower, which is in particular attributable to its lower content of sulphur-containing amino acids. Acetylation did not reduce the nutritional-physiological value of the easily soluble fraction of protein from Vicia faba, and impaired that of the difficulty soluble fraction but slightly.

[Amino acid composition of the unresorbed peptide fractions of the distal part of the small intestine in rats. II. Feeding of field-bean protein isolate with and without the addition of dialdehyde starch and of protein texturates from it].

Rats were fed diets containing 20% protein in the form of casein, protein isolate from sunflower seeds, protein isolate from field beans, model protein texturate made from field-bean protein isolate or model protein texturate made from field-bean protein isolate treated with dialdehyde starch and a nitrogenfree diet. The content in the distal small intestine of the rats was collected 3 hours after feeding, and the amino-acid compositions of the TCA-precipitable and TCA-soluble peptides (after separation of free amino acids) of the content were studied. The comparison of the amino-acid compositions of the two peptide fractions with the respective dietary protein showed no agreement.

[Amino acid composition of unresorbed peptide fractions in the contents of the distal part of rat small intestine. 1. Nitrogen-free diet and diets with casein, sunflower protein isolate and defatted sunflower seeds].

After feeding with protein containing diets the protein quantity increases in the aqueous supernatant (U1), in the trichloracetic acid soluble (U2) and precipitable (S2) fractions of the content of the distal part of the small intestine of rats. Independent of the dietary proteins the amino acid composition of both fractions (S2 and the peptides from U2) is similar in relation to protein-free feeding; a similarity with the amino acid composition of the dietary proteins doesn't exist. In relation to fraction S2 the peptides of fraction U2 show anording to the higher content of amino acids, which are difficult to liberate by protein cleavage, a high proteolytic degradation.

[Nutritive-physiological study of sunflower seed protein isolate and spun sunflower seed protein-casein fibers].

Compared with defatted sunflower seeds, in sunflower seed globulin isolates the content of lysine and sulphur containing amino acids is decreased, the content of phenylalanine is increased. The content of the whole essential amino acids of sunflower seed globulin isolate in relation to casein is decreased. The value of the enzymatic invitro available amino acids of sunflower seed globulin is comparable with casein.

[Nutritional study of field bean protein isolate and of spun field bean protein-casein fibers].

The amino acid composition of the different field bean protein isolates shows a good correspondence. In relation to casein the content of the whole essential amino acids is low. In the first line the low content of methionine and cystine limits the biological value of this proteins.

[Rheology and spinning of alkaline solutions of sunflower seed globulin and casein].

The specific demand of sodium hydroxide is determined for the dissolution of sunflower seed globulin, casein and a mixture of them to equal parts. In low protein-containing solutions it depends for sunflower seed globulin very much on the sodium chloride concentration. From sunflower seed globulin, casein and a mixture of them to equal parts are prepared with sodium hydroxide high protein-containing alkaline solutions.

[Effect of starchsulfate on properties of protein fibers].

Admixture of starchsulphate to an alkaline spinning solution of proteins increases the thermostability of the corresponding spun protein fibers.

[Spinning of rapeseed proteins].

Alkaline solutions of a mixture from rapeseed globulin and casein show plastic flow, which is influenced by protein concentration, relation of rapeseed globulin and casein, temperature and time of storage of the protein solution. The sodium hydroxide concentration with a great variability doesn't take effect on the rheological properties. With increasing content of casein in such alkaline solutions of rapeseed globuline and casein results an approach to NEWTONian flow.

[Changes in the nutritive physiological value of proteins modified by dialdehyde starch].

The reaction of dialdehyde starch with the proteins of certain model protein texturates produces changes in the nutrition physiological quality of the proteins. Under the experimental conditions chosen, these changes were barely or not at all detectable by amino-acid analysis. On using the technique of aminoacid liberation under in vitro conditions, these changes were evidenced only for lysine and arginine.

[Swelling properties and structural stability of spun protein fibers].

With spun protein fibers of casein and a mixture of casein and vegetable proteins results in a solution of sodium hydrogencarbonate an increased diameter of the protein fibers. The determination of this change makes possible an examination of the swellability and stability of the structure of protein fibers.