An Improved Process for the Extraction of the Plasma (Cell Contents) and the Separation of Cellulose from Yeast.
Year: 1897

page_text: An Improved Process for the Extraction of the Plasma (Cell Contents)
and the Separation of Cellulose from Yeast.
I, ALFRED DURANT WATSON, of Mill House, Mitcham, in the County of Surrey,
Merchant, do hereby declare the nature of this invention to be as follows;
-
The substance of this invention is a new method of separating the plasma and
the cellulose from yeast.
For many years past it has been known that the plasma of yeast was of high
nutritious value but the cost of extraction was too great.
My process not only reduces the cost of extraction but utilizes the cellulose
which I have found to be of considerable value for the purposes to which cellulose
is generally applied.
My process is as follows: I begin by washing the yeast in plain water and
repressing it in the manner which has been customary in the yeast trade for many
years past but in the case of hop resins being tenacious in character I employ a
solvent in the wash water. I then take the washed pressed yeast and desiccate it
either by gentle heat, or by a heated current of air, but preferably by contact with
some anhydrous substance which entirely removes the remaining water and leaves
the yeast brittle in which state it is easily ground and reduced to fine powder and
is then in a condition in which it may be offered for sale, but I prefer to mix it
with water after grinding and then to filter the liquid from the solid by which
means the full plasma extract may be obtained in a pure state, leaving the cellu-
lose behind to be treated for the purpose of cellulose. The plasmatic fluid is then
concentrated to the desired consistency by the method usually adopted for concen-
trating such fluids either in vacuo or otherwise and when the fluid has been
concentrated to about 1100 specific gravity I again filter it, as some of the
albuminoids having coagulated have fixed any hop resins which may have been
left in the fluid, the removal of which adds materially to the delicacy of the flavour
of the resulting extract.
For extracts where delicacy of flavour and purity are of less importance 1 con-
tent myself by placing the washed pressed yeast in a vessel and leaving it to
generate heat spontaneously and thus the cells break down and release their plasma
which is then filtered in the usual manner or I submit the washed pressed yeast
to hydraulic or other pressure and thus force the plasma from the yeast cell, or I
submit the washed pressed yeast to steam pressure which causes the yeast cell to
release the plasma which is then filtered as above described.
Dated the Fifth day of October 1897.
NEWNHAM BROWNE.
Agent for the Applicant.

page_text: An Improved Process for the Extraction of the Plasma (Cell Contents)
and the Separation of Cellulose from Yeast.
I, ALFRED DURANT WATSON of Mill House, Mitcham; in the County of Surrey,
Merchant, do hereby declare the nature of this invention and in what manner
the same is to be performed to be particularly described and ascertained in and
by the following statement:-
My invention consists in improvements in the method of separating the plasma
and the cellulose from yeast.
My process not only reduces the cost of extraction and enables the cellulose
which is of considerable value to be utilized but also produces an extract of great
clearness and brilliancy, of very great nutritive value and possessed of an agree-
able and palatable flavour.
My process is as follows;-I begin by washing the yeast in water and repres-
sing it in the manner which has been customary in the yeast trade for many years
past and in the case of yeast containing hop resins of a tenacious character I
sometimes find it advisable to wash in a solution of one of the well known solvents
for, such resins such as alcohol.
I may then proceed in either of the two ways which I shall call process 1 and
process 2..
Process 1. I take the washed repressed yeast hereinbefore referred to and desic-
cate it either by gentle heat or by a heated current of air or by contact with some
anhydrous substance such as anhydrous starch, which entirely removes the remain-
ing water and leaves the yeast brittle in which state after sifting from the starch
it is easily ground and reduced to an impalpable powder and is then in a con-
dition in which it may be offered for sale but I prefer to mix it with water after
grinding and then after the water has dissolved the desiccated plasma to filter
the liquid from the solid by which means the full plasma extract may be obtained
in a pure state leaving the cellulose behind to be treated in any way that may be
desirable as a by-product. The plasmatic fluid is then concentrated to the desired
consistency by any one of the methods usually adopted for concentrating such
fluids either in vacuo or otherwise and when the fluid has been concentrated to
about 1060 to 1100 specific gravity I again filter it to remove any of the albumi-
noids which may have become coagulated during concentration and which may
have fixed the remaining hop resins the removal of which adds materially to the
delicacy of the flavour of the resulting extract.
Process 2. I take the washed repressed yeast hereinbefore mentioned and place
it in a vessel and I allow the yeast to break down into a liquid state under the
influence of a slight rise in temperature. This rise in temperature will take place
spontaneously but I find that the delicacy of flavour and the brilliancy of the
resulting product are thereby somewhat impaired owing to the variation of tem-
perature which the yeast then undergoes, and I. find that if the vessel is main-
tained by some method of attemperation at a constant temperature of from 95°
to 98° Fahrenheit I obtain a final product which is more valuable than any
extract hitherto obtained. I therefore maintain my vessel at a constant teni-
perature of from 95° to 98° Fahrenheit and as soon as the yeast is broken down to
a liquid state which will be after a few hours I add a small quantity of some
antiseptic such as salicylic acid to check any tendency the extract may have to
become decomposed or altered in chemical composition. At this or any later
stage I add flavouring matters as may be desired. I continue to subject the yeast
4

page_text: to the constant temperature as above mentioned for from 20 to 40 hours that is
to say until the extract satisfies the following specific gravity test: -
I take a portion of the extract representing one pound of the original yeast
and after diluting with water to make up 30 fluid ounces and filtering, the
filtered extract should (after making due allowance for any added substance such
as flavouring, antiseptics or the like) give at 60° Fahrenheit a gravity of about 12
to 13 brewers lbs. per barrel or a specific gravity of 1033 or 1036 according to the
richness of the yeast under operation. When this part of the process is com-
pleted as determined by the above test the liquid is filtered in the ordinary way
and the cellulose residue set aside as described in Process 1. The filtrate will be
found to be a clear extract representing the whole or practically the whole of
the nutritious plasma of the yeast.
I find however that the extract at this stage contains a proportion of coagulable
albumens which give a cloudy appearance to the resulting product when it is mixed
with hot water and therefore when I wish to avoid this cloudy appearance I
prefer to raise the temperature of the filtered extract to a temperature of 180° to 200°
Fahrenheit so as to precipitate these albumens. I then refilter or decant the
extract and concentrate to the consistency of a paste or not as desired.
My concentrated product will be found on analysis to give a very high percen-
tage of albuminoids namely from 60 to 70% of albuminoids according to the class
of reast employed.
The extraction at this low temperature involves a considerable time and were
it not for the addition of the aforesaid antiseptic the first extracted portions of the
plasma would become spoilt, but with the antiseptic I am enabled by this process
to obtain the whole of the nutritive plasma from the yeast in the form of extract
without the use of digestives which tend to depreciate the value of the resulting
product and the extract obtained by my process is more valuable than any extract
hitherto obtained.
The extract may be taken as a food in any manner most agreeable to the user
and is particularly adapted for being mixed with water and taken in the same
way as beef tea, for making gravies or to be made up in the form of a lozenge or
jelly or to be spread in sandwiches or to be dealt with in any of the numerous
methods which are familiar to cooks, epicures, nurses, and others or to be used
as albumen or the various modifications thereof and for use in the manufacture of
other articles.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:-
1. The herein before described process of manufacture of a nutritious extract
from yeast as designated Process 1.
2. The hereinbefore described process of manufacture of a nutritious extract
from yeast as designated Process 2.
3. The improved extract obtained from yeast by Process 1, as hereinbefore
described..
4. The improved extract obtained from yeast by Process 2, as hereinbefore
lescribed.
תווד
T
3000