GB478570A - Improvements relating to yeast or protein preparations - Google Patents

Abstract

Vegetable protein materials containing at least 25 per cent of substantially undegraded protein which is substantially insoluble in water, e.g. soya meal, brewers' grains, and ground peanut cake, or casein are subjected preferably in a closed vessel to an aqueous treatment at temperatures sufficiently high to render soluble a substantial proportion, e.g. 60 per cent and over, of the protein in a few, e.g. 2--3 hours, the product being treated, if desired, after removing the fraction still insoluble as by centrifuging, with active yeast autolysate to degrade the proteins and give a food or medicinal product. The predigestion may be effected by heating the protein material at 100--135 DEG C. at atmospheric or higher pressure and the aqueous medium used may be acidified, preferably with phosphoric or other acid without action on the cellulosic constituents of the material; the acid used may be capable of reacting with a base, e.g. sodium carbonate, to form buffer substances for controlling the pH in the subsequent proteolysis. The predigestion may effect a partial degradation of the protein to amino acid.ALSO:Products rich in degraded proteins, for food or medicinal purposes, are prepared from vegetable protein materials containing at least about 25 per cent of substantially undegraded protein which is substantially insoluble in cold water, e.g. soya meal, brewers' grains and ground peanut press-cake, and from casein, by subjecting the materials, preferably in a closed vessel, to an aqueous treatment at temperatures sufficiently high to render soluble a substantial proportion, e.g. 60 per cent and over, of the protein in a few, e.g. 2-3, hours, the product, from which the fraction still insoluble may be removed, as by centrifuging, being mixed with active yeast autolysate for protein degradation. The predigestion may be effected by heating the protein material at about 100-135 DEG C. at atmospheric or higher pressure and the aqueous medium used may be acidified, preferably with phosphoric or other acid without action on the cellulosic constituents of the material; the acid used may be capable of reacting with a base, e.g. sodium carbonate, to form buffer substances for controlling the pH in the subsequent proteolysis. The predigestion may also effect a partial degradation of the protein to amino acid; it may be carried out with the material in dough-like form, and the treated material may be brought by heating, e.g. for about 2 hrs. in an oven at 120 DEG C., to dryness or semi-dryness before the yeast autolysate is added. The yeast autolysate may be prepared and may be used for the proteolysis as set forth in Specification 450,529. Examples of the treatment of soya meal and ground nut meal are given.