DE2344317C3 - Process for the production of high protein food and feed - Google Patents

Description

15th

The invention relates to a method for the production of foods and feeds with a high protein content Breeding of yeast in whey, which contains not only carbohydrates but also dissolved proteins, in which after When cultivation is complete, the substrate is thickened and the thickened mass is dried.

It is known to use Candida yeasts, other yeasts e.g. B. Saccharomyces cerevisiae and other microorganisms in oxygenated hydrocarbons, which are derived from petroleum fractions with 1 to 30 hydrocarbon atoms in the molecule, and then from the fermentation substrate obtained, the protein cells from the supernatant liquid by centrifugation, filtering (e.g. membrane filters [micropore filtration ], Dialysis, reverse osmosis), flaking, settling and decanting and then drying the thickened mass, e.g. B. in the spray, T ^r ori: mel, freezer, vacuum, rack, oven od. Like. Dryer (DE-OS 17 92 187). Depending on the starting substrate and the fermentation process, dried protein cells with a protein content of up to 80% by weight (from ethanol) can be obtained.

It is already known. Yeasts e.g. B. Candida yeasts. to grow in molasses and then to separate from the liquid by centrifugation, whereupon the thickened mass is dried. The dry matter is then used as feed or nutritional yeast used. This yeast contains 40 to 50% protein, depending on the yeast strain used.

In a similar way, whey from cheese dairies with approx. 4 to 5% lactose as a nutrient substrate, e.g. B. Saccharomyces fragilis. processed on yeast, which by centrifugation is obtained from the nutrient substrate (biomass) after at least extensive degradation of the lactic acid (DEOS 20 01 743). In addition to carbohydrates, both molasses and whey also contain dissolved proteins like albumins and globulins.

Hs is known to take the whey before it is processed Subject to ultrafiltration. This ultrafiltration holds back -lic dissolved protein substances, which are separated for themselves be worked up. The filtrate essentially only contains the dissolved carbohydrates and salts, and this filtrate is still used as a nutrient substrate for the yeast culture. H. the yeast-based protein is centrifuged off, washed and dried, although with this one Process a work-up of the dissolved proteins is possible and thus the usual process, the Separation of the biomass by separators, annoying contamination of the waste water with dissolved proteins can be avoided, it is desirable to avoid the complex processing by separators.

The object of the invention is seen in the production of high protein food and Feed by breeding yeasts to avoid separation with separators or centrifuges and To achieve a higher protein content of the product compared to the normal protein content of 45 - 50%.

The solution to this problem is for the method mentioned at the outset that after breeding the yeast and the dissolved protein are separated from the substrate by ultrafiltration and the thus thickened mass is dried. In the method according to the invention, the Ultrafiltration used after the cultivation, because it has surprisingly been shown that the yeast at ultrafiltration does not clog, but cleans the membranes of the ultrafilter. The process allows a higher protein content to be achieved in the product than before, as it is possible to use the dissolved To gain protein together with the biomass, which is particularly advantageous when using Saccharomyces fragilis is the case as yeast

It is often useful if the ultrafiltration takes place in two stages, namely in a first thickening process and in a washout followed by a second thickening to remove salt residues or the like in a cost-saving manner being able to wash out. The protein solution can be chemically bleached before or after the ultrafiltration will.

example

Whey from cheese factories with a lactose content of approx. 4% and a dissolved protein content of approx. 0.7% is vaccinated with Saccharomyces fragilis. This organism multiplies in this nutrient substrate and converts the carbohydrate content into protein. Subsequent to breeding is the entire mass ultrafiltered and so thickened to about 1:20. By adding water and repeated ultrafiltration salt residues can be washed out. The concentrate is now dried, using a drum dryer or spray dryers. The dry product contains approx. 55 to 60% protein. Since it is except the Cell substance of the microorganisms also contains the protein bodies, which are present dissolved in the nutrient substrate it has a significantly higher protein content and is therefore more valuable. Besides, that has Method has the advantage that a separation stage with centrifuges is superfluous.

Claims (1)

Claim: Process for the production of high protein food and feed by breeding Yeast in whey, which in addition to carbohydrates also contains dissolved proteins, in which after Cultivation the substrate is thickened and the thickened mass is dried, characterized in that that after the end of cultivation from the substrate the yeasts together with the dissolved Egg whites are separated by ultrafiltration and the mass thickened in this way is dried.