Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to the manufacture of chee3e by-product~
suitable for human consumption. This invention further relates to a method
for processing cheese whey ~o produce a very low moisture content, inexpensive
cheese filler which can bP mi~ed with other cheeses.
The whey by-products produced in the normal processing or manu-
facture of cheese are known to contain quantities of useful ~ats and proteins.
Prisr to this time, a number of processes have been developed to produce
products suitable for both human and animal consumption by removing these fats
and proteins from the whey by-products before they are discarded.
In a number of well known processes a Ricotea cheese product is made
by salting, heating and acidifying fresh whey in a cheese vat, skimming the
floating precipitated cheese solids and drying the solids. However, cheese
products made in this fashion are generally high moisture content cheese
products not suitable for grating and/or use as a cheese fillcr. Even prolonged
drying of the~e products, to the point of spoilage~ results in products having
moi~ture contents too high for use as a grated cheese filler product. While of
course the isture content can eventually be reduced to a suitable level, this
level is only reached after spoilage and wastage of at least a portion of the
cheese produce.
For example, Sanders, Cheese Varieties and Descriptions, ~. S.
Department of Agriculture Handbook No. 54, 1953 teaches a proce~ ~or makin~
Ricotta cheese product from 0.20h acidity whey by heating the whey to 200F.
addin8 sour whey or other coagulant and removing the floating precipitated co-
agulated albumin by dipping with a perforated ladle or dipping cloth. ~fter
draining and/or pressing in cheesecloth lined hoops the product may be marketed
as "fresh or ist Ricotta" having a moisture content of 68 to 73 percent. I~
the product is to be marketed as "dry Ricotta", the curd is fur~her drled by
pressing in perforated forms and drying in a curing room at 100F. or higher.
This "dry Ricotta" has a ~oisture content of 60% which i9 more than twice as
high as is suitable for a grated chee~e filler product. If any affort is made
to continue the drying to a low enough moi~ture content for a grated cheese
product, the curd would spoil before an acceptable moisture content could be
reached. The fact that this cheese product has such 8 high moisture content
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inherently results from the method of its manufacture which produces large curd
particles entraining considerable moisture.
In still another example, Kosikowski, Cheese and Fermented Milk Foods,
Cornell University, 1966 teaches that whole milk Ricotta chease may be made by
acidifying whole milk to pH 5.9-6.0, heating the milk to about 176 F. to
precipitate and coslesce the curd and recovering the cur~ by dipping. Any curd
not precipitated by the initial acidification may be coagulated by subsequent
acid additions. The resulting cheese product is "characterized by a high
. . .
moisture content very similar to cresmed cottage cheese" -- i.e., a moisture
content in excess of about 72%. This high moisture content ~8 attributable to
.
the precipitating of the curd whereby large curd particles are formed notwith-
standing thst fine curd flakes initiate the precipitaeion. The particle Qize is
in part caused by ehe effort to effect ~otal curd precipitatio~ by a single
massive acid addition. However, as a practioal ma~ter, not all of the curd will
precipitate at once and therefore subsequent small acid additions are employed
: to coagulate the remaining curd.
` '
- "Dry Ricott~", sui~able for grating, may be made from high moisture
~`` cheese by pre3sing the curd in~o molds for 24 hours at room temperature and
curing the cheese for several months at 50-60F. or for four weeks at 70F.
However, during this curing period spoilage occurs and it is necessary ~o clean
the cheese surface from time to time and to discard the spoiled waste.
Other procesRes are known for manuacturing by-products from cheese
whey. For example, U.S. Patent 3~?52~96l to Rodgers etal., describes a
process for recovering proteins from whey in which an anionic polyelectrolyte
flocculating agent is added to a whey solution containing a whey protein pre-
cipitate. The product produced by this process i~ whey protein curd having a
quasicrystalline structure. ~hile thi~ product has a high content of protein,
lt cannot be directly used a~ a human foodseuff, because such cheese-whey^by-
products do not have a par~icularly pleasing flavor or aroma.
It i8 therefore an ob~ect of the present invention to provide a pro-
cess for manufacturing a firm cheese filler product from cheese whey which
product exhibits a low (less than about 30~) ~oisture content.
It is another ob~ect of this inven~ion to provide a proce~s for
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manufacturing a low moisture content, fine cheese product suitable for grating
wherein the curd from whey precipitates in fine particle form as a result of
staged acid additions.
It is still another object of this invention ~o provide a process for
- manufacturing a low moisture content cheese product from chee~e whey wherein
the low moisture content may be achieved in commercially practical periods of
time without prolon~ed storing or curing and without spoilsge of any portion
of the precipitated curd.
It is yet another ob~ect of this invention to provide a process for
manufacturing from cheese whey a cheese product suitable for grating character-
ized by increased yield and low moisture content, which process carefully con-
trols the acidity and precipitation temperature of the whey.
Briefly stated, in accordance with the aforesaid ob~ects, cheese whey
i8 treated with a base to ad~u8t its acidity to within proper limits. Nex~, the
whey composition is heated to an elevated temperature and an acid is added in
stsges to cause fine particulate cheese solids to separate to the ~urface of
the whey. The cheese solids at the surface of the whey composition are then
cooked until the moisture content of tbe cheese solids i8 60 to 70 percent. The
cooked cheese solids are further heated u~ing low pressure steam to reduce the
moisture content to the range 20-30~, ater which the dried chee3e solids are
salted and grated to produce a cheese filler product having a low molsture
content. The chee~e filler products thus produced can be directly added to
other cheeses to produce cheese compositions having pleasing flavors which are
suitable for human consumption.
In carrying out the proce~s for making cheese filler according to
this invention, fresh whey i8 first filled into a cheese vat. The cheese whey
useful in this invention can be obtained ~rom the manufacture of ~ny kind of
cheese. For example, whey from the manufacture of Swi~ cheese, A~erican cheese,
cheddar cheese, mozzarella cheese or mNn~ter cheese can be used.
After the cheese whey has been placed in the chee~e ~at, salt9 usually
consisting of sodium chloride or any other phy~iologically compatible salt9 is `
preferably added. As is well-~nown, salt is sdded to the whey composition to
prevent spoilage of the subsequent cheese product and for flavoring purpose6.
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Thus, while it is not essential to add salt precisely at this time, salt i9
prefer~bly added before further prosessing to prevent spoilage or other chemic~l
breakdown of the cheese during subsequent process steps. The amount of salt
added cfln vary anywhere from one to one and a half pounds of salt per l,OOO
pounds of whey, preferably about one pound of ~alt per 1,000 pounds of whey.
A neutralizer is then added to the whey cheese composition to reduce
its acidity. The a unt o~ neutrali~er added should be sufficient to bring the
titrable acidity of the composition to the rsnge 0.10-0.12, preferably about
0.11 percent, although, if the composition already has a titrable acidity with-
in this range, no neutralizer need be added. A9 iS well known, titrable acid-
ity i8 a measure of the ~otal acid content of a composition. This is distinct
from pH, which is a measure of the hydrogen ion concentration of a solution.
A~ is appreciated ln the cheese-making art, observance of titrable acidity in
cheese-making processes can lead to different results than observance of pH.
In the proces~ of this invention it has been found that observance of titrable
acidity provide~ more accurate control of the separation of cheese solids from
the whey than observance of the pH. Specifically, it has been found that con-
` trolling the titrable acidity to within tha spec$fied range is critical since
8reater acidity leads to additional moisture in the precipitated curd and is
uneconomical while less acidity adversely affects yield.
The neutralizers which may be used in the proce~s of this invention
àre well-known in the cheese-making art. These neutralizers are bases which
are suitable for human consumption. For example, sodium hydroxide or potas-
sium hydroxide can be u~ed. In addition, a substance known as Nuflow, which
iB manufactured by Wyandotte Chemical Company and which i8 a crystalline compound
containing sodium carbonate, sodium bicarbonate and water re~erred to as sodium
; sesquicarbonate has been found to be a particularly effective neutralizer.
- The whey composition ls next hea~ed and uniformly mixed in the cheese
vat. It is very important that this heating step not be under~aken until after
30 the composition is neutralized to an acidity of about 0.10-~0.12 percent.
Otherwise, cheese solids in the form of heavy precipitates will sink to the
- bottom of the cheese vat and the whey composition will thus be unsuitable for
use in the process of thi~ invention. Heatlng continues until the temperature
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of the whey has reached 180-188F., preferably about 182F., at which time the
heat is adjusted to maintain the composition at this temperature. Since precip-
itation at temperatures above 188F. have been found to adversely affect yield,
and since it has been found that ater each stage of acid addition and precipi-
tation the whey temper~ture lncreases ~bout 2-3F., it is very desirable to
m~intain the whey ~emperat~re at the low end of the 180-188F. temperature range
prior to the first stage of ncid addition. This will insure that all precipita-
tion takes place in the 180-188F. temperature range. If the temperature is
permitted to drop below this range during precipitation, the precipitated cheese
solids will sink to the bottom of the vat irrespective of the fineness of ~he
cheese flake. It will be appreciated that subsequent cooking of the precipitated
cheese solids to reduce their moisture content, which is a critical step in the
process, c~n only be accomplished when fine cheese flake particles accumulate
at the top of the whey composition.
The whey co~position is then acidified in at least two s~ages to
cause the cheese solids in the whey to separate out and float to the surface
of the whey composition. Thi3 acidification i9 accomplished by adding an acid
substance to the whey composition so that the titrable acidity of ~he whey
increases to about 1.35 to 1.55 percent, preferably about 1.40 to L50 percent~
Care must be taken when the acid is added so that the cheese solids which
separate out float to the surface of the whey composition. For example, if ~he
`~ acid substance is added too quickly, the cheese solids form lu~py precipitaCes
which sin~ to the bottom of the vat and are thus un~sable in the process of
this invention. Preferably, the acid substance is added in three stages, and
the amcunt o acid added in each stage is ~dju~ted so that cheese flakes
approximately the si~e of medium-si~ed snow flakes fonm when the acid in each
stage is added. Unle~s the cheese precipitate psrticle size is controlled to
sizes of medium-sized snow flakes or smaller, a product having the requisite
drynPss and firmness cannot be produced. Acid additions to the whey should be
,
no more frequent than every five minutes in order that all the precipitation
caused by each acid addition can occur before more acid is added to the whey.
When the whey clears all precipitation h~s occurred and the next acid addition
csn be made.
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The acids that can be used to adjust the acidity of the whey in the
`- process of this invention are any acids which are suitable for human consump-
tion. The3e acids are well-known in the cheese-making art. For example,
citric acid, white vinegar or hydrochloric acids can be used. Al~o, "whey
starter", which is whey having a high acidity and "milk starteT" which is milk
having a hi8h acidity can be used.
After the acid substance has been added and the cheese solids in the
form of medium-sized cheese flakes or smaller have floated to the surface of
the whey composition, a layer of cheese solids approximately two to three i~ches
thick orms on the surface of the whey composition. This layer of cheese solids
is allowed to remain on the surface of the whey composition while heating is
continued, so that the cheese solids are cooked.
It has been found that if the layer of cheese solids is left undis-
turbed during the cooking step, soft spots will usually develop in the cheese
solids layer. Therefore, in a preferred embodiment o ehis invention, the
cheese solids are masticated during the cooking step ~o promote uniform cooking.
` This can be done by chopping the cheese solids with a dipper or by any other
suitable means well-known in the cheese making art.
It is also preferable to form a thicker layer of the cheese solids
on the surface of the whey composition. This can be done by skimming the cheese
solids from a large portion of the surface area to a small portion of the sur-
face area of the whey composition. The thicker layer o~ cheese solids thus
; formed can then be masticated again ~o that it cook~ firmly and uniformly.
Cooking of the layer of cheese solids is continued until its molsture
content decreases to 70 percent or lower, preferably to 60%, the attainable
moisture content resulting from cooking depending to a large extent on the
number of acid addition stages utili~ed. For example, lf two acid addition
stages are employed, it is difficult to reduce the isture content by cooking
for a commercially reasonable period much below about 66%. However, if three
or more acid addition stages are employed, there is no difficulty in attaining
a 60~ moisture content in the cooked cheese solids. Following moisture content
reduction to 60-70% by cooking the solids layer at the surface of the whey, the
cheese solids may be removed from the ~hee~e pan and dipped into cheesecloths
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or other suitable means to drain and cool. Alterna~ively, the cheese curd
solids may be separated from the waste whey by permitting the whey to drain
from ~he vat through a bottom drain line.
The cheese solids are next placed in a vat or container where they
can be subjected to indirect heating with pressurized steam. Generally the
-; cheese vat in which the precipitation took place is not designed to accept
:.
pressurized steam ag ~ heating medium and the cheese 801ids will usually have
to be moved to a suitable ~acketed container. Of course, if the orlginal cheese
vat can accept pres~urized steam it is that much more de~irable, in which case
the w~ey ~9 drained from t~e Yat be~ore press~riz~d ste~m heating is commenced.
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low pressure steam, up ~o 30 psig, is the preferre~ heating medium. 1~ th~
steam pressure is higher the steam temperature is too high ta allow su~ficient
control o~ the moisture reduction process and the cheese can be damaged. If
the steam is not pressurized to at least 10 psig, then mo~sture content
reduction ~o 20-30%, ~he final desired m~i~ture content, cannot be accomplished
in a single step in a resson~ble period of time. Within this range the steam
pressures suitable for use from the standpoint of process control and a~oiding
damage to the cheese depend upon the moisture content of the chee~e solids.
For example, pressures approaching 30 psig may be used i~itially while the
moisture content remains near 60%. However, as the cheese salids dry, the
suitable steam pressure range is considerably lowered. It is, therefore,
recommended`that a con~tant ~team pressure be used throughout drying of about
10 ~ig. At this pressure, drying can be sccomplished from 60-70Z moisture to
:j
20-30Z moisture in le~s than 5 hours3 usu~lly 4-5 hours.
Heating with ~he steam at temperatures i~ the range 175-215F., prefer
ably 210-215F., with constent mechanical agitation, should be continued until
the moisture content of the cheese solids decreases to 20-30%, and preerably
to about 25%. Agitation may be accomplished in any well known manner, such as
by use of a fork agitator or equivalent mechanical agitator.
The cheese solids may be salted prior to or followlng drying so that
the ultimate cheese filler product of this in~ention will have a ~alt content
of about 3 to 6 percent, preferably 4 to 5 percent. A~ i~ set forth above,
salt is added to cheese products to prevent spoilage and as a flavor enh~ncer.
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Thus, salt is added to bring the salt content oi the cheese filler product to
the required level. However, it should be understood that the salt may be
added anytime during ~he manufaeture of the cheese filler product so long as
the smount of salt in the ultimate product is main~ained between about 3 to 6
percent. The salt may be added to the cheese solids by any ~onventional salt-
ing technique.
After grating the 20~30 percent, preerably about 25~, moisture con
taining cheese product, the ultimate cheese filler produ~t of this invention
has been completed. The cheese ~iller product of this invention has a so~t
texture and an appearance similar to other inely grated cheeses. This cheese
f~ller product is suitable for human consumption and can be directly mixed with
other cheeses, such as parmesan cheese, sbrin~e cheese, romano cheese and
provoloni cheese, to extend tha mass of these cheese~ without afecting their
pleasing flavors. Since the different cheese-whey starting materials useful in
the process of this invention have somewhat different compositions, the co~po-
sition and texture of the cheese filler product of this invention varies slightly
depending on the type of whey used. However, it has been found that xegardless
of the type of whey used, the cheese filler produced according to this inven-
tion can be directly incorporated with various cheeses to extend them in the
manner set forth above.
Sinoe it ls a principal object of this invention to produce a low
moisture content cheese suitable for grating it will be appreciated that rapid
moisture content reduction is a critical aspect of the process. If conventionsl
~" drying techniques are used, vast storage facilities are necessary and many days
are wasted before the finished product is completed and ready for ~ale. Accord-
ing to the present process, the cheese can be comple~ely manufactured and on
the market in less than 24 hours. In addition, equipment costs are miniMized
and the need or skilled equipment operators is obviated. It 4hould be recog-
- nized, however, that an alternative drying technique useful in this inven~ion
`- 30 contemplates reducing the cheese solids moisture content to the range 40-50%
by heating using hot water or steam in the range 175-215F., grating the cheese
` and then further drying the cheese to the desired 20-30~/o range uslng conven-
tional, commercially available equipment, such as a fluid bed dryer marketed
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; by The Fitzpatrick Company. However~ lt should be understood that this alterna-
tive technique, al~hough producing the same dry cheese product in a commercially
reasonable period o time, is not nearly as desirable as the preferred pressur-
ized steam technique of the process herein described. This is because by using
the alternative technique the moisture content reduction from 60-70Z to 20-30%
requires two steps and because the suitable commercially available dryers for
the final moisture content reduction are expensive and require skilled operators.
As a result the economlcs of the alternative technique are not favorable,
While the invention has been completely described above, the following
example is provided for a better unders~anding o the nature of this invention.
, EXAMPLE 1
10,000 pounds of fresh whey from the manufacture of mozzarella cheese
is filled into a rectangular cheese vat equipped with an impeller in the form
of a long pipe. The pipe impeller is positioned parallel to the floor of the
vat and is adapted so that it rotates in a plane paraliel to the plane of the
vat iloor. The pipe impeller is internally connected to a supply of steam and
is provided longitudinally with a number of holes so that steam from the steam
source flows out of the impeller pipe in a horizontal direction.
To the fresh whey composition in the cheese vat approximately 10
pounds o salt, are added. At ~his point, the titrable acidity of the cheese
whey composition i9 approximately 15 to 18 percent, and 4 po~nds of ~uflow are
added.
Steam from the steam source is turned on and the impeller is caused
to ro~ate so that the cheese whey composition is uniformly heated to a temper-
ature of 182F. Upon reaching this temperature, the steam flow rate i6 reduced
90 that the composition remains at this temperature.
Approximately 12 ounces of citric acid are diluted in 8 gallons of
.~
fresh water and are ~hen added to the whey composition. As a result, cheese
flakes spproximately the size of medium-sized snow flakes separate out from the
whey composition and float to the surface of the vat. After at least 5 minutes
have passed to allow all precipitation possible from the first acid addition,
an additional 12 ounces of citric acid diluted in 8 gallons of water are then
added to the whey composition (which now has a temperature of abou~ 184-185 ~.
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causing more cheese flakes of approximately the same size to separate out from
the whey composition and float to the surface. Af~er abou~ another 5 minutes of
precipitation 12 ounces more of citric acid are diluted in 8 gallons of fresh
water and again added to the whey co~position (no~ at a temperature of about
187-180F.) causing a small additional amount of cheese flakes to separate to
the surface of the vat. After thls third addition of acid to the whey compo-
sition, the titrable acidity of the whey composition is approximately 1.45 per-
cent, and a layer of cheese solids approximately three inches thick and weighing350 pounds is formed on the surface of the whey compo3ition.
Heating i8 continued in order to cook the layer of cheese solids
floating on the surface of the vat at approximately 190F. During cooking, the
~ layer of cheese solids is intermittently chopped in its soft spots with a dipper
- to promote uniform cooking. After about 20 minutes, the mass of cheese solids
is slowly moved to the front half of the cheese vat by skimming to form a thick-er layer of cheese solids having a thickness of appro~imately five inches. This
thicker layer of cheese solids is also chopped in its soft spots with the dipperto ensure uniform cooking. Cooking of the cheese solids continues until the
thicker layer of cheese solids has a moisture content of approximately 60 per-
cent (about 1¦4 hours).
The cheese solids are next removed from the cheese vat and plsced into
cheesecloths to drain and cool. After the cheese solids are drained ~hey are
placed in a jacketed vat and salt is added to bring the salt content up to about3-6 percent. The cheese solids are agitated with a ork agitator and steam at
a pressure of about 10 psig is fed thro~gh the ~acket to uni$ormly heat the
solids. Heating is continued for about 4-4 1/2 hours at which point the moi~turecontent of the solids in the vat is about 25 percen~.
: The cheese solids are removed from ~he vat and grated. The product
is then sifted through a fine stainless steel mesh screen ~o produce 160 pounds
of the ultimate cheese filler product of this invention.
160 pounds of this cheese filler product are mixed with 40 pounds
of grated parmesan cheese to produce a composition having a pleasing flavor
substantially the same as grated parmesan cheese.
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EX~MPLE 2
Exsmple 1 was repeated except that the product was mixed with grated
romnno cheese. The resultant composition had a texture and flavor substanti-
ally the ~ame as grated romano cheese.
EXAMPLE 3
Example 1 was repeated except that cheese whey from ~he manufacture
of provoloni checse was used as the star~ing material, and the cheese filler
product obtained was mixed with grated romano cheese. The resultant composi-
tion had a flavor and texture substantially the same as grated romano cheese.
` 10 EXAMPLE 4
Example 3 was repeated except the cheese filler product was mixed
with grated parmesan cheese. The resultant composition had 8 flavor and tex-
ture substantially the same as grated parmesan cheese.
EXAMPLE 5
Example 1 was repeated except that cheese whey from the manufacture
of romano cheese was used as the starting material and the product obtained ~as
mixed w~th grated parmesan cheese. The resultant product had a texture and
flavor substantially the ~ame as grated parmesan cheese.
EXAMPLE 6
The process of Exsmple 1 was repeated except that the citric acid was
added in only two steps. Initially 18 ounces of citric acid was diluted in 8
gallons of water a~d added to the whey composition. After at least 5 minu~es,
an additional 18 ounces of citric acid diluted in 8 gallons of water was added
to the whey composition. The cheese solids layer which formed at the ~op of
the whey composition was heated in the same manner as in Example 1 except that
cooking for a similar period of time reduced the moisture content of the cheese
solids to only about 66 percent. All ~ubsequent treetment of the cheese solids
was the same ss in Exsmple 1. However, it required a full 5 hours of low pres-
sure steam heating to achieve a final cheese moisture content of 25~.
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