Note: Descriptions are shown in the official language in which they were submitted.
This invention relates to an "instant" yogurt and to the process for
its manufacture. The instant yogurt is in ~ dry particulate form which can
be reconstituted by admixture with water to provide a product of true, natural
yogurt texture and flavour.
Yogurt is coagulated milk product obtained by lactic acid fermenta-
tion through the action of Lactobacillus bulgaricus and Streptococcus thermo-
ph lus from milk, milk solids and other m:Llk products. The microorganisms in
the final product must be viable and abundant. Fresh yogurt is a living pro-
duct subjec~ to changes of continuous fermentation. Thus, it is non-uniform
and perishable. It would therefore be desirable to provide a rnodified yogurt
which can be stored indefinitely and which can be reconstituted simply by ad-
ding water and stirring, thereby to provide a product having a texture and
taste identical to true natural yogurt~
One proposal to provide instant yogurt was made by E.A. Ferguson, Jr.
in United States Patent No. 3,080,236 dated March 5, 1963. This patent de-
scribes a process which includes first making natural yogurt by implanting a
pure culture in milk. After incubation for 12 hours, the resultant yogurt is
reduced in volume by evaporation, then placed in vacuum driers until all
moisture is removed9 after which the dried product is pulverized. In produc-
ing a powdered yogurt of this type, substantially all the beneficial micro-
organisms are destroyed and so the product is not a true, natural yogurt.
~ erguson further teaches that when yogurt in its usual form is
dehydrated it cannot be reconstituted into the smooth, creamy, pleasant
tasting product by the simple addition of water as might be expected. To
overcome this difficulty, Ferguson's process comprises drying the culture
of yogurt in a vacuum dryer, and powdering the residue to be used as a
partial ingredient of an instant yogurt product~ Preferably the dried,
powdered culture residue is prepared from a culture which has been over-
grown to some extent. Then, the dried, powdered ~ogurt culture is mixed
iitn ~o~dered rnilk~skimmed rnilk, norl-fat milk, or the ~ike), and with
'
3f~1
~tarch, preferably dried, cooked starch, to form the composltlon of that ln-
vention. Flavourings, sweeteners, or the like, may be added as desired. W~len
this composition is mixed with water, a yogurt-like composition is in~tantly
formed. The resulting yogurt-like product, although it is not true natural
yogurt, was alleged to look, taste and act like yogurt in all respects. Fer-
guson's yogurt product, comprising dried yogurt culture, a water-soluble dried
milk, an edible fat and a water-soluble dried starch was thus adapted when
mixed with water to form a synthetic yogurt composition. Ferguson's lnstant
yogurt, therefore, is lacking in the full benefits of good quality true natur-
al yogurt.
Another proposal was made by Hockenberg et al. in United StatesPatent No. 3,321,319 patented May 23, 1967. While Hockenberg et al. suggested
that it was known to subject milk and dairy products, Eor example, yogurt, to
freeze-drying in a "conventional" manner, whereby the crude product, after the
freezing step, was dried by sublimation of the ice under vacuum, and thereby
a satisfactory dried product was obtained, they also taught that such proced-
ure was not industrially viable because of economic considerations. Conse-
quently, as an improvement on this old teachings, they provided a free~e-
dried liquid dairy product by a procedure where a dairy product, e.g. milk,
was separated into a serum or skim portion and a coagulated residue by mechani-
cal means. Then the coagulated residue, preferably immediately following its
separation, was subjected to cooling and then was subjected to a free-drying
step in accordance with conventional methods. The serum constituent was dried
in its separated state, employing known drying methods. ThereaEter, the pro-
ducts of both drying steps were mixed together to form the final dried pro-
duct.
Hockenberg et al taught that by the mechanical separation of the
aqueous serum portion and the coagulated residue, those salts and sugar con-
stituents which would have an adverse effect lf the entire mass had been pre-
concentrated in a single step, remained in an aq~!eous serum portion, and
3~
thereby the coagulate provided an especially suitable starting material for
subsequent freeze-drying. It was taught that separation of the serum portion
and the residue could be carried out mechanically in a variety of ways, either
by centrifuging, sieving, or settling of the solution. While the patentees
taught that their process would be applicable to yogurt, it was, in fact, not
so, i.e., they taught a process for the preparation of a yogurt-curd powder,
comprising the steps of: (a) treating yogurt ~ilk with an enzyme to form a
coagulated protein residue and a serum portion; (b) separating the protein re-
sidue from the serum; (c) cooling and freeze-drying the protein residue; (d)
drying the serum portion; and (e) admixing the dried serum and protein residue
to form a dry yogurt product~ The drying process would kill many of the yo-
gurt-producing bacteri~, and thus the reconstituted product would then not be
a true natura~ yogurt.
Yet another proposal was made by Bohren, in United States Patent No.
3,793,465 patented February 19, 1974 which taught a method for the Manufacture
of an acidified milk product in powder form in which a fraction of a milk pro-
duct inj-powder form, biologically acidified to a pH of 4.2 to 4.4, was comr
bined with another fraction of a non-acidified milk product in powder form in
order to obtain a pH above 5.2. Immediately after reconstitution with water,
the weight of the water was 5 to 10 times the weight of the powder, and an acid
compound with controlled release was combined with the two fractions of milk
product. Nevertheless, the method included the step of drying the milk product
to form powders by conventional methods, e.g., by injection into a drying
chamber at a temperature of 60 - 100C. through spray nozzles. Such spray-
dried product could not contain any live yogurt bacteria, and so when recon-
stituted car.not be considered as being true, natural yogurt. Moreover, the
spray-dried powders were mixed with an edible acid in particulate form, the
edible acid being citric acid, lactic acid or acid Lruit concentrate. Each
particle had a coating of edible fat having a melting point bet~een 45 and
,
-- 3 --
3~
60~C., and an edible emulsifier thereon. The edible acid constituted from 50
to 80% of the weight of the particles. The particles after coating were be-
tween 50 and 250 micrometers in size. The quantity of edible acid was such
that, after 2 hours subsequent to reconstitution, the product had a pH of
4.3. The edible fat coating had a composition and thickness such that all
acid coated therewith was released in rom l/2 to 2 hours after reconstitution.
Such reconstituted product cannot be considered as being true, natural yogurt.
Yet another proposal which had been made was in the Barberan United
States Patent No. 3,985,901 patented October 12, 1976. That patentee deseribed ¦
lQ a complex process for producing and preserving acidophil milk which was mainly
based on the combination and harmoni~ation of cultivating and drying processes
(which was alleged to be generally applicable to other fermented milks, and
yogurt). Such process was alleged to permit: obtention of abundant lacto-
bacillus cultures; grading the contents of the live lactobacillus in the pro-
duct by the weighted addition of excipients corresponding therewith; a prac- !
tically unlimited preservation without the need of refrigeraticn, since the
product would be in a dry powdered rform; an easy and rapid recons~itution,
ready to be consumed, by means of simply restoring the original water; im
proving the organoleptic qualities by the incorporation of harmless hydrophil
substances which provided a creamy consistency, or fruit essences and sweeten-
ing substances to satisfy the taste of certain consumers or to lessen unde-
sirable flavours or colours; possibility of being consumed by certain persons
(diabetics, pre-diabetics, etc.) due to the incorporation of suitable natural
or synthetic sweetening agents, instead of the conventional sugars; possi
bility of approaching the organoleptic qualities of yogurt, due to the
rational mixture of the dry mass thereof with the dry mass of yogurt in
suitable proportions so that the predominating character of the acidophil
milk was not lessened; and relatively economical production and commerciali-
~ation costs since inexpensive processes of careful spray-drying (whereby the
main ~ass of the nutritious medium of the fermented mil~ is obtained in a dry
3g~
form) are combined with other more expensive lyophilization processes having a
small but rich mass of microorganlsms (whereby the appropriate and standar-
dized quantity of live and dry lactobacillus is contributed to the main spraye~ :
mass). Such patented process for drying and preserving acidophil fermented
milk in powdered form so that it could be readily reconstituted with water
comprised the following twelve steps 7 i. e .
1. culturing a lactic acid producing microorganis~ in a cultu~e
medium to produce an inoculum;
2. sterilizing milk to be fermented, and adjusting the solids
content of such milk to approximately 16 to 20% solids content;
3. fermenting the milk of step (2~ with the inoculum of step ~;
(1~ in a continuous or discontinuous manner;
4. inoculating a culture medium with the inoculum of step (1)
and fermenting ~mder conditions sufficient to obtain a large proliÇeration
of the lactic acid-producing microorganism;
5. enrishing the solids content of the fermented milk of
step ~3) with
- a. 15 to 20% sugars or other sweeting -agents and
b. 1 to 2~ thickening agents;
6. homogenizing the sweetened, fermented milk of step (5) by
mechanical means to destroy any gelled particles and to improve fluidity;
7. spray drying the product of step (6) at from 130 to 180C.,
where the survival of lactic acid-producing microorganisms is desired,
or at 180 to 300C. where such survival is not necessary but increased
yields are desired;
8. agglomerating the product of step (7~ in a moist atmosphere
and then drying it in a fluidized bed;
:. ;. .. . : ,:; : ,
9. lyophili~.ing the lactic acid-producing microorganisms from
the fermentatlon of step (4) by rapid freezing under condi~ions to pro-
mote the survival of the microorganisms and thereby produce a foamy
freeze-dried mass co~prising live lactic acid-producing microorganisms;
10. grinding the foamy mass resulting from the lyophilization
of step (9) to a granulometry similar to that of the product of step (8);
ll. mixing the lyophilized product of step (10) with an excipient
so as to achieve a lactic.~acid-producing microorganisms content in the lyophi-
li~ed product of 10l microorganisms per gram
12. mixing the lyophilized product of step (ll) with the product
of step (8) in a proportion ofapproximately 40 parts by weight of the
product of step (8) and 2 parts by weight of the product of step (11? so
that when reconstituted with water in an amount of 42 grams of fermented
dry milk per 100 to 125 cc of water, there is obtained a creamy, liquid,
fermented acidophil milk having about 200 million lactic acid producing
microorganisms per cc. Clearly this complex process does not solve the
problem of readily, easily and economically providing a dried powder
which can be instantly be recDnstitoted into a true natural yogurt.
- Finally, Schur? in Unit~d States Patent No. 4,066~794 patented
Janua~y 3, 1~78 provided an instant yogurt p~epa~ation adapted, when ~ixed
with water to form a composition whose smooth texture and nutritional value
was comparable to that of natural yogurt. The preparation consisted essenti-
ally of dried yogurt powder in which the culture was deactivated, a dormant
dried yogurt culture, water-soluble dried milk powder, sodium alginate in an
amount of 5.20 percent by weight to act as a setting agent to form a viscous
colloidal solution in which the milk and yogurt constituents are dispersed,
an organic dispersing agent to promote the uniform separation of the fine
particles of the solution, the organic dispersing agent being sugar in an
amount 69.26~ by weight, and a sequestrant constituted by F~TA in sufficient
. .
-- 6 --
~33~
quantity to inhibit Rrecipitation reactions that would otherwise cause the
sodium alginate settin~ agent to curdle and create lumps in the composition.
This also is not a true yogurt since the yogurt powder used is in the deacti-
vated state because of the processing of natural yogurt with heat to remove
all moisture therefrom which acts to destroy the culture.
Accordingly, the art i5 still faced with the solution of the
problem of providing an "instant" yogurt powder. Accordingly, an object of a
broad aspect of this invention is the provision of a simple process for readily,easily and economically providing a dried powder which can instantly be re-
constituted with water to form a true natural yogurt.
By one broad aspect of this invention, a process is provided `~
for preparing a powder which can be instantly reconstituted to a true yogurt,
the process comprising: (1) innoculating a liquid milk product with sufficient
bacterial mixture of Lactobacillus bulgaricus and Streptococcus thermophilus in a
ratio of 0.5:1 to 1.5:1 and incubating said innoculum at a temperature of 41 -
46C. for a suf~icient amount of time to provide a solution having pH of 4.3 -
4.4; (2) subjecting the yogurt so prepared to sub-zero temperatures until
said yogurt is frozen to a temperature below its eutectic point; and ~3) removing
substantially all the water from sald frozen yogurt in a closed environment sub-jected to low absolute pressure and a heat input withln a controlled temperaturerange of -40C. to ~40C. and having a condensing surface therein maintained at
; a temperature below -40C. to -80C., and converting said ~reeze-dried yogurt to
particulate form, thereby to provide a shelf-stable powdered yogurt.
By one variant, the liquid milk product is skim milk.
By another variant, th~ liquid milk product is reconstituted
skim milk provided by dissolving skim milk powder in water.
By another aspect, the innoculating step includes incubating
the innoculum with said Iactobacillus bulgaricus and Streptococcus the _ philus
at a ratio of 1:1 for a period of 4 - 6 hours at a temperature of 41 - 46C.,
30 -- and then incubating said partially incubated innoculum at a temperature of 36 -
- 7 -
- : - , :: ~, ' :,,, - .:.' ,., . .::': :: . : :,, i
~ ~33~
38C. for a further period of 2 - 4 hours, thereby to provide variations in
tex~ure, taste and aroma in the yogurt ~o-produced.
By a further aspect, the innoculating step includes innoculating
with an amount of a bacterial mixture amounting to 2% o~ the volume of the
liquid milk product of Lactobacillus bulgaricus and Streptococcus thermophilus
in a ratio of 1:1, and including ~rom 0.5-1.5% of Lactobacillus acidophilus,
thereby to provide variations in flavour in the yogurt so~produced.
By a variation thereof, the reconstituted skim milk solution
is heated to 85 - 95%C. for 10 - 20 minutes and is then cooled to 41 - 46C.
prior to being innoculated.
By another variation, up ~o one-third of the skim milk powder
is replaced with whey powder.
By still another variation, the process includes the step
of subjecting the liquid skim milk product to ultrafiltration prior to being
innoculated, the~eby substantially to eliminate molecules having a molecular
weight less than 10,000.
By yet another variation, the process includes the step of
passing the liquid milk product through a molecular sieve prior ~o being innoculated,
thereby substantially to eliminate molecules having a molecular weight less
than 10,000.
By another variant, the process includes the step of adding
fruit or other flavourings, e.g., strawberry, red raspberry, blueberry, cherry~
peach, apple, blackberry, pineapple, etc. to the yogurt prior to being subjected
to steps (2) and (3).
By another aspect, the dry yogurt powder has the following
composition:
-- 8 --
% by weight
Protein 23 - 36
Carbohydra~e 5 - 34 ~
Fat ~0.8 - 3.5 :
Moisture 3 ~ 5
Ash 8 - 9 ~;
Other balance
By another aspect1 the reconstituted yogurt has the following comr
position:
% by weig_t
Protein 8.2
Carbohydrate1.5 - 4.5
Fat 0.9 - 1.0
Ash 1.5 - 2.5
Other balance
Calories 30 - 75
By a further aspect, the dry yogurt powder has th~ following comr
position Protein 26 - 36 ~ :
Carbohydrate5 - 34
Fat 0.8 - 3.5
Moisture 3 - 5
Ash 8 - 9
Other balance
and also containing freeze-dried fruit therein.
_ 9 _
- - :: - - . : -: : :: .- :: : :~ : : - :. .: : .
' .' ~ . ' ' ' . . ',, . . , , . , ! . .
33~
` The intrinsic ~niq~le novelty behind the principles of the
present invention which provide an unobvious improvement over the generalized
teachings of the Mockenberg et al U.S. Patent referred to above resides not
only in the production of the crude product (the yogurt) but also in the
particularization of the freezing and drying steps. It is known that the
optimum temperature and pll for the ~rowth of ~ ptococcus_thermophilus is
37.7C. and 6.8 respectively, and for Lactobacillus bulgaricus is 43.3C. and
6.0 respectively. Neverthless, by aspects of the present invention, the
production o~ the yogurt is carried out by incubating the microorganisms at
a controlled temperature of ~ 46C. until the yogurt has a pH 4.3 - 4.4.
This provides a yogurt product which is especially adapted for the freezing
and drying steps within_the ambit of aspects of this invention. This particular
procedure is not disclosed nor suggested by Hockenberg et al. In addition, the
variant whereby the incubation takes place at two contro]led temperatures, i.e.
a first higher temperature of 41 - 46C. and then a second lower temperature of
36C - 38C. provides a yogurt product which is even more specially adapted
Eor the freezing and drying steps.
The yogurt is solidly frozen before being subjected to very
low absolute pressure (high vacuum) and a controlled heat input by a pL-ocedure
which differs significantly from Hockenberg et al's freeze dryin~ in the
conventional manner.
The yogurt must be solidly frozen below its eutectic point,
e.g., to a temperature to -60C. to -90 C. The
so-frozen yogurt is dried in a closed environment by sublimation by providing
a condensing surface having a temperature of -40C. to -80C. or less and
an absolute pressure of between 5 and 250 microns, preferably to 25 microns
of Mg and subjecting the closed environment to a source of heat input controlled
between -40C. and ~65C., to drive the water from the solid to the vapor state
by sublimation.
h~ - 9a -
33~!~
~ The basic reason for pre-Ereezing the yogurt is to lock
its solid particles firmly into position, so that moisture can be sublimed,
and physical and chemical reactions cannot take place, and so that the
microorganisms are maintained dormant. To assure that the yogurt is frozen
to below its lowest eutectic point, the freezer is maintained at a temperature
of -60C. to -90C. If the lowest eutectic point is not achleved, the yogurt
may appear to be fro~en, when in fact a small percentage may yet be in the
liquid state. This small volume of liquid will case the solids in suspension
to react, spoillng the results of the dehydration. On the other hand, freezing
the product too far below its lowest eutectic is unnecessary and poor practice
economically. Optimum rates of sublimation are obtained by the maintenance
o an optimum vapor pressure differential between product ice and condenser
ice. In practice, the yogurt is generally frozen to a temperature
of not lower than -60 C. to -80 C.
The removal of the water is achieved in a closed zone provided
with a condensing surface. It is important that the condensing surface be
placed in the direct path of migrating vapors. As vapor molecules leave the
product ice, they migrate toward the low pressure areas in the system, first,
the area just above the product ice, then~to the localized low pressure area
surrounding the condenser. On contacting the condensing surface, migrating
vapors give up their heat energy, turn to ice, and are effectively removed
from the system. Air and other non-condensable molecules emitted from the
product pass the condensing surface and are evacuated by the vacuum pump.
According to aspects of this invention, the yogurt can be dried efficiently with
a condensing surface temperature between -40C. and -80Co
The removal of the water is further achieved in the closed
zone which is subjected to a very low absolute pressure. The purpose of the vacuum
system is to evacuate non-condensable gases from the chamber, c}eating the
vacuum necessary for efficient sublimation. This effectively reduces the
resistance to the flow of water vapors migrating from product to the condenser.
~ - 9b -
~ ~ ,, , ;, , ,: - . ~ :
3~3
The absence of air in the system also substantially prevents oxidation
during drying. The pressure should be 250 microns, preferably 25 microns
or less. Ultimate vacuum should be as low as 5 microns.
The r~moval of the water is still further achieved in the
closed zone which is subjected to controlled heat. Heat is applied to the ice within
the yogurt to maintain the migration of water vapors fronl the yogurt toward
the condensing surface. The application of heat to the yogurt supplies the
necessary energy to drive off these vapors, raising the temperature of the
yogurt (an amount corresponding to the increase in vapor pressure at the
ice interface). In the beginning of the cycle, the total volume of the
yogurt is frozen and will accept a high heat setting Later when a portion
of the product is dry and offering resistance to the vapors released from
below, a lower heat setting is desirable to avoid "melt back", i.e. change ,
in the yogurt from solid to liquid. In the inal portion of the drying cycle,
a higher setting may again be desired to drive off any remaining bound
molecules. Therefore, it is necessary that heat supplied to the product be
controlled. According to the process of an aspect of this invention, the
range of control should be between ~40C. and 40C. By these means the
temperature of the yogurt during the freeze-drying process is controlled
so as to avoid the aforesaid "melt back". The product temperature was
maintained within the range of -40C. o -60C. at the commencement of the
drying and at +30C. + 5~C. during the later stages of the drying.
,:
: ::, : :, , :. ~ ~ .: : ;` : .: . .' :,
3~
The following are examples of aspects of this inven~ion.
Example I - Plain Skim Milk Instant-Yogurt
To 1000 grams of skim milk powder, 2600 gm of water is added.
The mixture is stirred until all the powder is in solution. The skim
milk powder had the Eollowing characteristics:
Typical Chemical Analysis
Carb~hydrates (Lactose) 52,3%
Proteins 35 5%
Minerals 8.0%
Moisture 3,0%
Fat 0.8%
' ,: ;~:
'
- 9d -
Physical Charac~eristics
Colour - white to light creamy
Flavour and odour - sweet and clean
Free from hard lumps
~icrobiological Analysis
Standard Plate Count less than 50,000/gm
Coliform less than 50/gm
E. Coli negative
Salmonella negative
The solution is heated to 90C. and kept at that temperature for
15 minutes. The solution is then cooled to 43C. and a bacterial mixture of
Lactobacillus bul aricus and Streptococcus thermophilus in a ratio of 1:1 is
g . .
added to the solution. If desired, 0.5 - 1% of Lactobacillus acidophilus may
also be added as part of the bacterial mixture. The bacterial may be obtained
from the American Type Culture Collection at Bethesda, Maryland. The amount
of bacterial added is dependent on the volume of the solution but is usually
at 2~ of the total volume of the milk solution.
The solution with the bacteria is incubated for 6 hours between 41 ~
46C. until the pH is 4.3 - 4.4. If desired, the incubation may be done in
two steps, i.e. one step for 4 - 6 hours at 41 - 46C. and the second step for
2 - 4 hours at 36 - 38C. until the pH is 4.3 - 4.4. At that pH, the milk
solution exists as a firm gelled yogurt. Fruit or other dehydratable flavour-
ing agent may also be added to the yogurt gel so formed.
This gel is spread on a tray sepcially designed to fit into a freeze-
dryer. The spread yogurt is placed in a freezer at -60C. and kept there un-
til the yogurt is frozen.
The frozen yogurt is then placed into a precooled freeze-dryer
equipped with a cooler-heater so that the temperature of the tray can be as
low as -40C. and as high as +40C. or more. The frozen yogurt i9 now dried
for a sufficient period of time until most of the water is removed. The
-- 10 --
dried yogurt i5 powdered and can be kept on tha shelE at room temperature for
at leas~ 6 months or longer without deterioration.
The composition of the dry yogurt powder is as follows:
Protein (N x 6.38) 35.23
Carbohydrate (reducing sugars)33.10
Fat (Soxlet) 0.56
Moisture (oven) 5.00
Ash (funlace) 8.19
Other ~difference)` 17.92
Total 100.00
Titratable acidity (meg/100 g) 103.66
Aerobic colony count (/g) 310
Coliforms (MPN/g)Nil
Staph (/g) C50
Salmonella Negative
The dried yogurt powder can be reconstit~lted by adding the desired
amount of tap water, resulting ~n a smooth creamy substance with the same
qualities as the true natural yogurt made before freeze drying.
In one example, to make one serving of yogurt, take 30 gm of powder,
add 150 gm of water and mix thoroughly. The yogurt can be either eaten
immediately or cooled in a refrigerator depending on the preference. Fruit
or any other flavouring can be added to the yogurt after reconstitution with
water. The tangy typically cultured flavour of the yogurt combines well with
the various fruits and yields more pleasing fruit flavour.
.. ~
.. : . . .: .. : ~ : .. ~
:. : . : :: : :
COMPOSITION OF _CONSTIT~TED INSTANT YOG~RT
Protein 8.2%
Carbohydrates 4.5%
Fat 1.0% .
Ash 2.5%
Calories 60-75
Example II - Low Calorie and ~ow Sodium Yogurt J
To 1000 grams of skim milk powder, 2600 gm water is added
and thoroughly mixed until the skim milk powder is completely in
solution. The solution is then concentrated by ultrafiltration, e.~.,
with an AMICON (registered Trade Mark) ultrafilter or with an AscoR
UF-225 (registered ~rade Mark) unit with ~FM (high flux membrane) or
holofiber tubes with a molecular cut-off of 10,000. This system sub-
; stantially eliminates molecules smaller than 10,000, which includes
the sugars and minerals. The substantial elimination of sugar lowers
the calories of the products. Yogurt maae from skim milk powder has
60-75 calories per 100 grams. By the above ultrafiltration process,
the calories per 100 grams of yogurt will be 30-40.
Water lost during the ultrafiltration proces: may later be added, as
well as essential minerals and vitamins~ However, for those who are on a low
sodium diet, (essential for people with high blood pressure and kidney
disease:), sodium-free yogurt may be prepared by the ultrafiltration method.
After the ultrafil~ration, the preparation of instant yogurt follows
as in Example 1, lncluding heating the sol~ttion at 90C. for 15 minutes,and
then cooling prior to incubation thereof.
- 12 -
~:
~3 ~
~,`
COMPOSITION1 LOWER CALORIE-RECONSTITUTED
INSTANT YOGURT
Protein 8.2%
Carbohydrate 1.5% '~
Fat
Ash 1.5%
Calories 30-35
Example III - Low Calorie Instant Yogurt
Follow procedure given,in Example II. A low calorie instant
' :
yogurt is produced by passing the milk solution through a molecular sieve, ~
e.g. that known~by the Trade Mark of SEPHADEX column or that known by the ~'
Trade Mar~. of BIO-GEL column. This method fractionates s1~bstances according
to their molecular wieght, which are eluted off the column. The ~ugars thus
coming off the column can be elimdnated. '
._, :, ~ : :
This process also dilutes the total mixture which is concentrated by
ultra-filtration'to its original volume.
The production of the instant yogurt follows the description ,
of Example I.;
Example IV - Plain Instant Yogurt ; ' ~
The method is the same as~for Example I, but one-third~of the skim
milk powder is replaced with whey powder~ reducing drastically the cost
20 ~ of the final product.
`
:
13 -~
~' ~
~L~L~'~V
The composition oE the whey used was as follows:
Typical Chemical ~nalysis ~-
Carbohydrate (lactose) 73.0%, minimum 70%
Proteins 12.5%, minimum 12.0%
Minerals 8.0%~ maximum 9.0% .
Moisture 3.5%, maximum 5.0%
Lactic Acid 1.4%, maximum 2.5%
Fat 1.0%, maximum 1.25%
Colour
Uniform light cream colour.
Texture
Free from lumps. that do not break up under moderate pres-
sure.
Soluhility Index
0,3, maximum 1.25j50 ml
Sediment (scorched particles)
Equal to standard chart Disc B
Microbiological Analysis
Standard Plate Count less than 50,000/gm
Coliform less than 50/gm
E. Colî negative
Salmonella negative
- 14 -
L33~
The composition of the dry yogurt powder was as follows: :
Protein (N x 6.38) 28.04
Carbohydrate (reducing sugars) 32.20
Fat (Soxlet~ ~ 1.03
Uoisture (oven) 11.4Z
Ash (furnace~ 8.67
~` Other ~difference~ 18.64
Total 100.00
Titratable acidity (meg/100 g~ 90.20
Aerobic colony count (/g) 460
: Coliforms (MPN/g~ ~ Nil
Staph (ig) ~50
Salmonella Negative
,
:
: :
. ~.
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- 15
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