R.R. Riel

A Study of the Chemical Composition and Nutritive Value of Leaf Protein Concentrates

Abstract Leaf protein concentrates from alfalfa and from clover obtained by solvent-precipitation and by heat-coagulation have been examined for their chemical composition, their nutritive value and their digestibility. The amino acid composition is not affected by the process of precipitation except that solvent precipitation seems to retain more methionine and less leucine than the heat process. Alfalfa and clover have similar amino acid patterns except that alfalfa has more cystine, aspartic acid and serine than clover. The lipids retained with the protein by the heat process contain much more linolenic and less palmitic, stearic, oleic and linoleic acids than those by the solvent process. Acetone retained more linoleic and linolenic acids and less stearic and palmitoleic acids than alcohol. The lipids of clover had more stearic and oleic acids than those of alfalfa. More mineral elements except Na and Fe and more carbohydrates were found in the solvent-precipitated concentrates than in the heat-coagula. Alfalfa protein concentrate was more digestible and had a higher P.E.R. value than clover protein concentrate. Both, however, were inferior to casein. Dispersibility in water was greater for solvent-precipitated than for heat-precipited concentrates.

Diffusion d’eau et de solides solubles pendant la coagulation des fibres de protéines

Resume Dans les procedes de filage des proteines la fibre est coagulee par immersion dans une solution d’acides et de sels. Le taux de diffusion des substances solubles et de l’eau, ainsi que la migration du front de coagulation, ont ete mesures dans des fibres en cours de formation. Les resultats obtenus indiquent que la coagulation de la fibre s’accompagne d’un phenomene de double diffusion et que le rapport des taux de transfert k’ est egal a 3.58.

Propriétés rhéologiques de solutions contenant des protéines de soya et de l’alginate en vue du filage de ces solutions

Resume Dans le but de prevoir la vitesse de sortie et le debit de la solution de filage a travers une filiere, connaissance qui est essentielle dans le procede de filage des proteines, nous avons calcule pour deux types de solution de filage, les parametres n, Po et C qui definissent parfaitement lecoulement de solutions visqueuses de proteine a travers un capillaire. Les solutions de filage etudiees ont les caracteristiques des fluides non-newtoniens, pseudoplastiques.

Irradiation du Jus de Pomme I. Effets des rayons γ sur Ie taux de filtration et Ia viscosité1

Abstract Freshly extracted, apple juice was submitted to different doses of γ rays (75 to 600 Krads). Filtration rates were measured and it was observed that, by increasing the dose of irradiation, the filtration rate was increased. A minimum of 150 Krads appeared necessary to produce changes in filtration ability. Observations on the viscosity of irradiated juices are in the same order as those made on the filtration rates: as the dose increases, the viscosity decreases. However differences in viscosity do not explain alone differences in filtration rates. It has been observed that a gel is formed on the surface of the filter and irradiation decreases this formation.

Le Régime Alimentaire de I'Avenir

Summary The food concept of the future The world food situation is alarming. The per capita food supply is not improving, unless our efforts are directed on two fronts, that of bending downward the population curve and that of bending upward the food production curve, the so often predicted world famine will become a reality. Countries with food surpluses are few and their granaries are getting empty. Consequently every country should aim at attaining at least a positive balance in respect to food supply. Food Science and Technology will continue to develop new food products. The concept that will predominate in future developments is that of bringing together into food products all essential nutrients irrespective of their source. The task is then to give to that food the most desirable parameters of quality such as taste, texture, appearance and convenience. These convenience fabricated foods will have to be superior to natural foods regarding nutritive value, taste, texture and cost. It is highly essential that most countries of the world become engaged in sizable Food and Nutrition Centers for developing all food resources. This is one requirement to guard humanity against the tragedy of hunger.