Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
1;~7;~ 5
PROCESS FOR PRODUCING A SEMI-MOIST
FRUIT PRODUCT AND THE PRODUCTS THEREFROM
BACKGROUND OF THE INVENTION
I. Field of the Invention
This invention relates generally to food preservation
and sweetening, and more particularly to the preservation
of blueberriesl cherries and similarly constituted fruits.
II. Description of Related Art
Listed below are the prior art patents and disclosure
materials of which the applicant is aware:
"Studies of Reversible Compression of Freeze Dried RTP
Cherries and Blueberries", U.S. Army Natick Labora-
tory Technical Report No. 70-52 Fl, 1970, Rahman,
A.R., Taylor, G.R., Schafer, G., Westcott, D.E.
U.S. Patent No. 2,899,319, Issued July 30, 1959; "Dehy-
- dration of Cherries", Powers, M.J., Norman, J.D.
U.S. Patent No. 3,356,512, Issued December 5, 1967;
"Method of Making Freeze Dried Artificially Sweetened
Fruit Products", Lemaire, N.A., Peterson, R.D., As-
signors to Kellogg Company, Battle Creek, Michigan.
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.,.
;5
U.S. Patent No. 3,395,512, Issued July 30, 1968; "Method
of Freeze Drying Fruit and Combining With Dry
Cereal", Vollines, W.I. Renyon, R.E., Barnett, S.,
Bowden~ H., Assigned to General Foods Corp., White
Plains, New York.
U.S. Patent No. 3,467,530, Issued September 16, 1971;
"Process of Freeze Drying of Blueberries", Schar-
schmidt, R.K., Kenyon, R.E.
U.S. Patent No. 3,511,668, Issued May 12, 1970; "Artifi-
cially Sweetened Freeze Dried Food", Vollink, W.L.,
Scharschmidt, R.K., Kenyon, R.E., Assignors to Gen-
eral Foods Corporation, White Plains, New York.
U.S. Patent No. 3,80~,610, Issued April 23, 1974; "Method
for Making a Compressed, Freeze-Vacuum-Dehydrated
Blueberry Product of Increased Density", Rahman, A.R.
U.S. Patent No. 4,341,803, Issued July 27, 1982; "Method
of Producing Dry Fruit Chip", D. Koshida, K. Sigisa-
wa, J. Majima, R. Hattori, of Japan.
The aforementioned prior art utilizes freeze-drying
to reduce the moisture content of the products, i.e., blue-
berries, cherries and other fruits. Certain patents apply
artificial sweeteners by spraying or dipping the fruit
before or after freeze-drying. They attempt to produce a
low moisture content in the product that would be rehy-
drated before eating. The following is a discussion of
the prior art listed above:
U.S. Patent No. 2,899,319 discloses a process for the pro-
duction of dehydrated cherries comprised of sulphited pit-
ted cherries. The process involves freezing the sulphited
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cherries then dehydrating by vacuum and heating medium to
produce a product that can be rehydrated readily in li-
quids before eating.
U.S. Patent No. 3,356,512 discloses a process for rapid
artificial sweetening of pieces of freeze-dried fruit pro-
duct, i.e., peaches, that are readily rehydratable. In
this patent, the artificial sweetener in a solvent, i.e.,
water, is applied to freeze-dried fruits which are then
dried to a final product with moisture content not to ex-
ceed 3%. The patentees acknowledge difficulties and indi-
cate unsuitability of using sucrose to sweeten the fruit
before or after freeze-drying.
U.S. Patent Nos. 3,395,022 and 3,467,530 disclose process-
es and improvements of a process to manufacture dehydrated
fruit, i.e., strawberries, peaches, blueberries and bana-
nas for use with cereal products, such as breakfast food.
The fruit product has a very low moisture content, i.e.,
blueberries 1.5~, and is capable of rapid rehydration in
milk within 30 to 180 seconds. These patents include
slow/gradual freezing of the fruit to form large ice crys-
tals in the cells to rupture cell walls to facilitate pen-
etration of the artificial sweetener in the fruit.
Ice rupturing detrimentally affects shape and chewi-
ness of fruit. Another destructive method used in these
two patents is the cutting or puncturing by pricking of
the skin and cellular structure of the blueberry fruit
before freeze-drying. This destructive process to fruit
skin and walls results in encouraging leaching of the
anthocyanins (the blue coloring material) from the blue-
berries during the rehydration process into the surround-
ing liquid, i.e., milk or cream, this bleeding is undesir-
able, which causes an unappetizing color/appearance in the
surrounding liquid and cereal.
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s
U.S. Patent No. 3,511,668 describes a procedure to artifi-
cially sweeten freeze-dried foods, i.e., strawberries,
blueberries and peaches. The patentees refer to difficul-
ties in adding sugar in solution or dry form to sweeten
the fruit to desired level and freeze-drying the product.
Thus, their described procedure to sweeten the fruit in-
cludes dipping or spraying solutions containing artificial
sweeteners on fruit before freeze-drying to a low moisture
content of 2~3% to produce a product that reconstitutes in
milk or cream in 30-60 seconds. The processing procedure
of slow freezing of the fruit product is used in this
patent to form large ice crystals to rupture cell walls to
enhance penetration of the artificial sweetener. Specifi-
cally, blueberry fruits are pricked or pierced to develop
holes in the skin and cellular structure of the berry to
provide the enhanced penetration.
U.S. Patent No. 3,806,610 discloses a process for making
compressed, freeze-vacuum dehydrated blueberries by sul-
fiting the fruit, freeze-vacuum dehydrating to a moisture
of 0-5~, heating and compressing, under pressure, the de-
hydrated fruit.
U.S. Patent No. 4,341,803 discloses a process for making
dry fruit chips, i.e., apple, pineapple, muskmelon, apri-
cot, persimmon and papaya for use as snack food. The pro-
cess entails adjusting sugar content of the sliced fruit
particles or pulp, then drying the chips by freeze-drying
followed by microwave drying, then vacuum drying until
their moisture content is approximately 5%. It is stress-
ed that successive drying in three stages, by freeze-dry-
ing, microwave irradiation under vacuum and vacuum-drying
are essential for the production of this product. It is
also mentioned that if only the freeze-drying stage, out
of the three mentioned drying stages, is employed, it is
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not possible to produce the desired product. The three
drying processes are related in that sequence to achieve
the purpose of that patent.
The present invention and product overcomes the prior
art problems, mentioned above, by controlling the moisture
content of the product and its sweetness without damage to
the skin of the fruit or cell walls, and retaining therein
the natural color and flavor of the fruit, and through
minimal residual surface moisture reduces energy usage and
through freeze-drying and sudden release of vacuum, collap-
ses the treated fruit providing a product which is differ-
ent in appearance, enhanced in taste, shelf life, feel and
touch in one's hand and palate.
Summary of the Invention
A process for producing a sweetened dried fruit pro-
duct having a moisture content in the range of 10% to 40%
including coating the fresh fruit with sugar, effecting
osmotic fluid sugar exchange within the fruit wherein
fruit juices migrate outward from the fruit and sugar mi-
grates into fruit by osmotic exchange until the sugar con-
centration reaches an equilibrium across the fruit without
disturbing the natural skin of the fruit and producing
sugared fruit and sugared fruit syrup, separating the
syrup from the fruit, rinsing the fruit to remove surface
sugar and/or syrup from the fruit, removing excess free
surface moisture, and freeze-drying the fruit in a vacuum
atmosphere including the rapid release of vacuum over a
relatively short period to collapse the fruit to a rela-
tively wrinkled, solid, chewy and palatable condition.
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A semi-moist fruit product having a moisture content
from 10%-40%, a wrinkled appearance and chewy palatable
condition produced by coating the fresh fruit with sugar,
effecting osmotic fluid sugar exchange within the fruit
wherein fruit juices migrate outward from the fruit and
sugar migrates into fruit by osmotic exchange until the
sugar concentration reaches an equilibrium across the
fruit without disturbing the natural skin of the fruit and
producing sugared fruit and sugared fruit syrup, separa-
ting the syrup from the fruit, rinsing the fruit to remove
surface sugar and/or syrup from the fruit, and freeze-
drying the fruit in a vacuum atmosphere including the
rapid release of vacuum over a relatively short period to
collapse the fruit to a relatively wrinkled solid, chewy
and palatable condition.
Contrary to known prior art, the important principle
of this invention is a sugar-syrupping process, followed
by a washing-rinsing, freeze-drying with moisture control
process. Preferable advantages of the invention are as
follows:
To produce a novel food product comprising semi-moist
(10-40%) blueberries, cherries and the like in which the
moisture and sugar content are regulated to enhance the
flavor, improving the texture, palatability and shelf life
of the product;
To produce a food product of the character set forth
in which the preserved food can be utilized as a cooking
ingredient in combination with other foods and mixtures,
but which is ready-to-eat off the shelf as a snack food;
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To provide an enhanced food product as set forth
above, in which the process of preservation provides a
food product of consistent quality, sweetness, moisture
content and flavor, but which food product is also indi-
vidually separated to permit measured quantities to be
readily effected with minimal sticking of one food piece
to another;
More specifically, to provide preserved food of the
character mentioned above having an intermediate moisture
content of from 10% to 40%, eatable as both a mixture ele-
ment or as a snack food, being readily accommodated as an
ingredient in cereals, cookies, muffins, candy, ice cream,
i.e., in all instances where use of the fruit in its natur-
al state might be contemplated, but because of the inabil-
ity of natural fruit to withstand storage, travel, hand-
ling, etc., such fruit could not previously be readily
used;
To provide a secondary by-product comprising leached
sweetened fruit syrup which is freeze-dried and preserved
in a crystalline state, and which has an unexpected natur-
al flavor and color associated with the natural fruit;
To provide a preserved fruit of the character men-
tioned above, producing a by-product of the character men-
tioned, the fruit being produced in a consistent commer-
cial manner, having markedly special superior properties
over the same fruit produced by known processes, which is
concentrated to afford reduced shipping weight which, by
having a low moisture content and high sugar content, de-
ters the growth of microorganisms, and thus has an extend-
ed shelf life and longer sales potential, and through its
preservation, can be sold through normal marketing chan-
nels without the usual freezing, canning or special hand-
ling and merchandising; a semi-moist fruit which is a
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. . .
free-flowing product facilitating handling, packaging and
measuring as well as accommodating it as a part of mix-
tures; and in which the fruit is hardy and less fragile
than in its natural state and is relatively elastic or
compressible, thus permitting it to be readily packaged
without the inherent dangers of bruising or handling dam-
age which results when attempting to accomplish the same
with the fruit in its natural and/or canned or frozen
state, to utilize a novel process to produce the food pro-
ducts as recited above.
These, together with other and specific advantages of
the invention, will become apparent from the following
description taken in conjunction with the drawing forming
a part thereof, in which:
Brief Description of the Drawing
Figure 1 is a schematic illustxation of a system for
effecting the process of the invention; and
Figure 2 is a schematic illustration of another sys-
tem for accomplishing the process of the invention.
Description of the Preferred Embodiment
The basic principle in this invention is to coat
fruit with granular sugars to initiat~ a sugar-syrupping
process followed by a washing-rinsing and freeze-drying
process. The sugar-syrupping process uses a natural phen-
omenon, provides a non-destructive method to remove liquid
from the fruit and allows for the entrance of sugar mole-
cules into the fruit parts and cells. This non-destruc-
tive method for removal of fruit juices through cell
walls, stem end-scar or fruit skin and the impregnation of
the fruit parts with sugar molecules relies on the princ-
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1~7~)65
iple of osmosis and osmotic pressure to leach out fruitjuice toward the sugar particles outside the fruit. As
more juice exits from the fruit, the sugar particles begin
to dissolve and hence the syrupping process progresses.
With more juice leaving the fruit cells and fruit, more
liquid accumulates in the sugar-syrupping-soaking environ-
ment resulting in more sugar dissolving into the solution.
As syrupping continues, more sugar particles/molecules
dissolve into the liquid causing the osmotic pressure of
the syrup outside of the fruit to rise more than that in-
side the fruit, which causes sugar molecules to move into
the fruit and into its cells and vacules. (This process
is enhanced by several factors to be mentioned later.)
The process of syrupping is allowed to continue,
fruit juice exits from the fruit, sugar particles dissolve
into the juice forming syrup, and sugar molecules move in-
to the fruit, until a specific equilibrium, as indicated
by soluble solids contents, is reached.
An important step of this invention is to remove ex-
terior syrup on the fruit by washing, rinsing, or blotting
excess syrup from the now equilibrium/sweetened fruit be-
fore freeze-drying. Failure to adequately perform this
wash separation results in a sticky, adhering product due
to the drying of the syrup on the outside of the fruit,
and greatly reduces the quality of the product and pre-
vents the product from ease of flowing or measuring which
is an essential characteristic in modern commercial pro-
cessing, ingredient measurement, mixing and packaging sys-
tems.
Another step of this invention is the mechanical re-
moving of excess surface water after washing or rinsing
the fruit. This greatly reduces the freeze-drying time
and in turn reduces production costs, since energy and
time is required when excess water is present.
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Another important part of this invention is the speed
at which vacuum is released in the drying chamber to ob-
tain the desired shape and appearance characteristics of
the final product. This invention achieves a "collapsed"
shape and texture of the semi-moist fruit. It is essen-
tial to release the vacuum in the freeze-drying chamber
very rapidly (within 1 or 2 minutes). During freeze-dry-
ing, vacuum is maintained at approximately 400 microns Hg.
The rapid change in pressure around the fruit causes its
walls to collapse, thus enhancing the fruits texture. If
vacuum is released slowly (in 15-20 minutes), the fruit
will retain a more spherical shape and will be "hollow" to
the touch of hand and teeth.
Referring to the drawing, indicated at 10 is a mixer
or tumbler which is filled in the conventional manner.
The first step of the process concerns mixing fruit and
sugar. The fruit can comprise both wild lowbush or culti-
vated highbush blueberries, and/or other types of wild or
cultivated, pitted cherries, and/or other types of fruit
and/or pieces of fruit each of which contain various ra-
tios of sugar when in their natural state and depending
upon when they are harvested; both frozen and fresh fruit
can be utilized in the process of the invention.
The ratio of the fruit, i.e., blueberries, cherries,
etc., may range from l to 5 parts of fruit to one part of
sugar with a preferred ratio of about three parts of fruit
to one part of sugar. The sugar comprises various types
of sugar, such as sucrose, fructose or dextrose. However,
other types of sugar may be used in this process including
both granular and liquid forms as is illustrated by the
Examples that followO
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To attain good and uniform mixing/coating of the
fruit and sugar, the fruit is placed in the tumbler 10,
and the sugar is added gradually while the tumbler or
coater is operating. This achieves uniform coating of the
fruit.
Next, after the fruit is properly sugar-coated, the
syrupping step is initiated. Indicated generally at 12 is
a soaking tank, which may incorporate integral electrical
heating means indicated generally at 14, or any comparable
heating means, such as hot gas, steam water bath, or the
like. The soaking tank is preferably mounted upon articu-
lated supports 16, 18, which are mechanically operated in
any suitable manner for raising, lowering or gently oscil-
lating the soaking tank during the syrupping step. The
supports also facilitate tilting of the soaking tank 12 to
ensure good drainage from the outlet tube 20 at its down-
stream end.
The sugar-coated fruit from tumbler 10 is placed in
soaking tank(s) 12 or trays and permitted to stand several
hours, usually for up to 12 hours at conventional room
temperatures of about 70-80F. for the syrupping process
to proceed. Heat may be applied to the soaking tank(s) to
accelerate the syrupping process. The soaking tanks can
also be placed in hot water baths or in a tunnel with hot
air circulation. Using too high a temperature, i.e., in
excess of 140, can cause too rapid evaporation of mois-
ture, thus adversely affecting syrup yield and fruit qual-
ity. The preferred temperature range is from about 70-
80F.
The syrupping process is further enhanced by gentle
rolling or vibration of the soaking tank,(s), oscillation
by supports 16, 18. This movement accelerates distribu-
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1.~7~C)65
tion of warm temperature, and in turn, thawing of the fro-
zen fruit, and assisting in sugar dissolving in the li-
quid.
The duration of the syrupping period depends on the
condition of the fruit at harvest, the fruit temperature
(frozen v. fresh), the holding tank temperature, and the
amount of shaking/rocking of tanks. The desired or opti-
mum osmotically-induced equilibrium is then determined by
Brix scale measurements of the syrup outside the fruit and
juice extracts from the fruit. The Brix scale is a hydro-
meter scale for sugar solutions so graduated that its read-
ings at a specific temperature represent percentages by
weight of sugar in solution. In the case of blueberries,
the syrupping process ends when the Brix of the syrup out-
side the fruit reaches 35-40%. At this point, the soluble
solids readings of juice inside the fruit, the sweetened
blueberries is 22-27%.
As mentioned earlier, during the sugar-syrupping
step, the natural, but generally unexploited, phenome~on
of osmosis provides a non-destructive, relatively gentle
method of removing liquid from the fruit without punctur-
ing the skin. Some of the liquid is replaced by sugar
molecules entering the fruit through cell walls, stem end
scar or fruit skin and utilizes osmotic pressure for the
exchange. Osmosis causes the fruit juice, i.e., liquids
with lower solids contents (10-12% in blueberries), to
leach out of the fruit, moving toward the sugar coating on
the outside of the fruit. As the juice leaves the fruit,
the sugar particles begin to dissolve and the syrupping
commences. With more rapid juice exiting from the fruit
cells, stem end-scar and parts of the enclosing skin,
there results an increased accumulation of syrup in the
sugar/syrupping/soaking environment resulting in more su-
gar going into solution. With continuation of syrupp-
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ing, more sugar particles (molecules) dissolve into the
~merging liquid giving rise to a pressure differential be-
tween the inside and outside of the fruit. The resulting
exchange between fruit juice and sugar provides a non-des-
tructive method of sweetening of the fruit through move-
ment of sugar into the fruit cells and vacules. This is
evident by the significant increase of more than 100% in
the amount of soluble solids, largely sugar, in the juice
within the sweetened fruit; as much as a threefold in-
crease. Additionally, it was common heretofore in the
prior art, to consider the blueberry skin to be imperme-
able to moisture exchanges. Accordingly, the prior art
resorted to pricking or puncturing the skin of the blueber-
ries before freeze-drying. However, unexpectedly in the
processes of the present invention, the osmotic exchange
resulted in conditioning the fruit skin to facilitate the
freeze-drying step without puncturing the fruit skin.
After reaching the desired equilibrium, the soaking
tank 12 is then tilted toward its downstream end toward
the exit tube 20. The contents of the tank 12 are dis-
charged into a combination sieve/conveyor 22 at which time
a major portion of the sugared fruit syrup descends into
compartment 24 and exits at discharge tube 26 to be col-
lected in suitable containers or vats and subsequently
treated as will be described. Suffice it to say that the
sugared fruit syrup generated or produced is richly en-
hanced by the natural products color, flavor and aroma
through its natural generation by osmotic exchange. This
runoff is rich in color and flavor, is suitable as a basic
ingredient in the manufacture of jelly, jams and pancake
syrups. The yield of syrup is approximately 50-60% and
sweetened fruit about 40-50% relative to the initial mix-
ture of fruit and sugar.
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It is to be noted that the sugar is the vehicle that
initiates and continues the osmotic action. Most of the
sugar is salvaged in the syrup or runoff after the fruit
is sweetened. Thus, the addition of more sugar to produce
jelly, drinks, etc., is substantially eliminated, and the
sugar of this process has a multiple unexpected function
of being a vehicle, and a basic ingredient of a usable
mixture of natural fruit juice with characteristic color,
flavor and aroma, and sugar, which will be subsequently
concentrated and crystalized, as will be described.
The sieve/conveyor 22 includes a second downstream
compartment 27 having a gravity outlet 28. The sieve/con-
veyor passes beneath suitable water jet means 29 from
which cold, clean rinse water is discharged. The amount
of rinse water is sufficient to insure that substantially
all excess adhering syrup is removed from the exterior of
the individual fruit or pieces. The cold water is at a
temperature of about 40-70, preferably 40-45 F., and the
conveyor sieve can be appropriately oscillated to slightly
jostle the fruit thereon to insure good contact with the
rinse water. The temperature of the rinse water is pre-
ferably maintained at 40-45 F. so that in addition to
rinsing off excess syrup and sugar particles, it provides
a secondary function of pre-cooling the fruit in prepara-
tion for the freeze-drying process.
Alternatively, as will be later described relative to
Figure 2, the sweetened fruit may be completely immersed
in rinse water by dipping; the conveyor/sieve may have a
run (not shown) descending into a suitable clean running
bath of rinse water at approximately 40-45 F. for a rela-
tively short period of time, i.e., from about 10-20 sec-
onds being the immersion period.
1;~7;~S
Still further downstream in Figure 1 and overlying
the downstream end of the conveyor/sieve is a water remov-
al means 30 comprising a plurality of conventional air
jets or "air knives" 31; the sieve/conveyor is preferably
vibrated or shaken where the fruit passes beneath the jets
31 thus affording partial drying of the surface of the
fruit, and providing a secondary runoff product at 28,
which is directed to suitable containers or vats for sub-
sequent treatment. The secondary runoff, which is more
dilute than the syrup per se collected at 26, sugarwise,
and depending upon the percentage of soluble solids, pro-
vides an ingredient for the production of wine, for ex-
ample. Clearly, the process involved utilizes substan-
tially all of the fruit being preserved, the salvaged
fruit juices and the treatment sugar.
The removal of syrup and excess rinse water during
the sieve/conveyor step(s) reduces the freeze-drying time
of the fruit. This results by the reduction of moisture
content in the fruit, i.e., sweetened blueberries after
the syrupping process contained approximately 70% mois-
ture; this fruit after rinsing and surface air drying con-
tains approximately 64-65% moisture. This is particularly
important in large scale, commercial installations, and
appreciably reduces the expenditure of energy and freeze-
-drying costs, and improves the condition of the preserved
product by eliminating sticking of the final semi-moist
product.
The next step comprises freezing of the fruit where
the fruit is either IQF (individual quick freezing) or
vacuum frozen.
From the conveyor/sieve 22, the sweetened, de-syrup-
ped, rinsed and de-watered product may be transfered to an
IQF (individual quick freeze) tunnel 32 where it is fro-
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zen, and then placed in cold storage at 50 in a low temper-
ature preferably -10 F., until the later, freeze-drying
process. This is an important feature for scheduling
large commercial production runs, especially when using
fresh fruit in the mixing/sugar/syrupping process, since
the period of availability of fresh fruit is usually
short, i.e., for blueberries about 6-8 weeks.
Sweetened, rinsed, and surface dried fruit which has
been stored at 50, or immediately after rinsing and sur-
face drying, is then freeze-dried in chamber 34, incorpor-
ating the usual seals and controls, where the fruit is
freeze-dried to the desired moisture content level. For
example, the sweetened fruit was freeze-dried by placing
it in ribbed trays 26" long x 13" wide x 2" deep and
placed in a freeze-drying chamber with a condenser setting
of -30to -35 F., oil temperature of 220 F. and platen
temperature of 180 F. to 220 F., vacuum of 400 microns
Hg, and freeze-dried until the product temperature reached
75-100 F. The duration of the freeze-drying cycle
varied according to temperature settings and moisture
level desired (10 to 40%). Final product temperature in
the freeze-drying chamber of 70 F, 80-90 F, and 95-100
F. coincides with product moisture content of 35-38%,
20-25%, and 12-18%, respectively.
It should be here noted that to obtain the desired
wrinkled/collapsed appearance, and elasticity/chewiness of
the product, vacuum in the freeze-drying chamber 34 (ap-
proximately 400 microns Hg) was released rapidly (within 1
to 2 minutes). Rapid release of the vacuum resulted in
collapse of the fruit to give the desired form, appearance
and touch to the hand and teeth. When the vacuum is re-
leased, the chamber is filled with either air or nitrogen.
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The fruit (blueberries or cherries), was then scraped
off the freeze-drying trays of chamber 34 onto conveyor 35
which directs the product to mixer 36 where it is treated
with an anti-caking agent. Several anti-caking agents
were used (i.e., Durkex 500 , calcium stearate, Can-
tabTM). From mixer 36, the coated product is discharged
onto conveyor 38 for subsequent packing.
In summary, the invention entails the manufacture of
sweetened semi-moist fruit products. In this invention,
liquids from fruits are leached out and sugar molecules
are impregnated or transferred into the fruit parts and
cells by an osmotic syrupping process. In syrupping,
fresh or frozen fruit (blueberries of the lowbush and
highbush types and cherries), were mixed with sugar at
different ratios. The fruit-sugar mixture was let stand
and syrupping, where fruit juice defuses out of the fruit
and sugar molecules dissolve in the emerging liquid and
then migrate into the fruit. The syrupping process was
accelerated by regulating temperature and adding mixing-
movement to the fruit/sugar/syrup mixture. At a specific
end point, the syrup and sweetened fruit were separated.
For example, when the Brix scale of the syrup reached 35-
40% and soluble solids in juice of sweetened blueberries
reached 22-27%, the sweetened blueberries and syrup were
separated. Excess adhering syrup was removed from the
sweetened fruit by washing or rinsing with cold water.
Free water on the surface of the sweetened fruit was then
removed by subjecting the fruit to shaking/vibrating move-
ments and to jet air blasts. The fruit was then frozen
and held and then freeze-dried to moisture levels of (10~
40%) subject to end-use. The fruit was then coated with
anti-caking material (such as Durkex 500 , calcium stear-
ate, CantabTM, or others), and packed in various size and
type containers.
~ . . . .
1;~7~ i5
Referring to the syrup runoff received at outlet 26
of the sieve/conveyor compartment 24, as was previously
mentioned, the sugar constituted as syrup, had a multiple
function, i.e., to initiate and maintain osmotic exchange
or differential pressure on the fruit resulting in the
fruit being sweetened and made uniform in consistency and
taste, while the sugar/syrup takes on an unusually char-
acteristic color and flavor of the fruit. Referring to
Figure 2, an alternate system for preserving the fruit is
illustrated, similarly functioning units will be identi-
fied with reference numerals used in Figure 1. The basic
steps, i.e., sugar coating the fruit in tumbler 10 and
soaking the sugared fruit at a controlled heat in tank 12,
are accomplished as was previously described.
Next, the soaked fruit with a sugar level in osmotic
equilibrium is discharged onto sieve/conveyor 22' and the
syrup decends into compartment 24' and out of the outlet
tube 26' to be recovered in suitable containers or vats
for the uses previously described.
The fruit is discharged into a cold water rinsing vat
30' to a pump manifold 29' from which the rinsed fruit is
directed through conduit 28' onto a second sieve/conveyor
48, preferably of the vibrating type. The fruit, which is
rinsed, then passes beneath water removal means 31l com-
prising air jets or knives, as in the previous embodiment,
which functions to remove the surface water from the
rinsed fruit. The second sieve/conveyor has an underlying
compartment 27' into which the water and/or rinse solution
drain as they did in the earlier described embodiment.
The materials washed off the fruit, as it is being
dried, are directed to a make-up water system, including a
tank 40 communicating with a water inlet 42 (for make up~
and a drain 44. The tank is operatively connected to a
-18-
~ ;~7~ i5
pump 46 for directing circulating water through 47 to the
rinsing vat 30' or bypassed back to the tank 40 through
by-pass pipe 48.
Fruit is then IQF (individually quick frozen) or
vacuum frozen before freeze-drying as was described with
respect to the system of Figure 1.
In the past, various methods have been used to con-
centrate fruit juice to powder for subsequent use in bak-
ery products, beverages, jellies, puddings, and other des-
serts. Drum drying has been used in dehydration of pow-
dered cranberries, tomato juice, pea and bean soup, apple
flakes, fig powder, etc. However, products suffer certain
amounts of heat damage due to the contact with a relative-
ly hot surface throughout the drying cycle. Since these
fruit powders are sensitive to heat damage, drying temper-
ature and time of exposure are critical factors; minimum
heat and/or less time must be used.
.
Spray drying has been used in dehydration of milk,
eggs, coffee, citrus juices, corn syrup solids and tomato
juice, but the products may tend to become hygroscopic and
low in melting point resulting in sticking or caking prob-
lems to the interior of the spray drying system or caking
in the package.
Several spray drying aids such as sucrose, corn syrup
solids, lactose, gums, alginate, pectic substances, milk
solids, starch, sodium carboxymethyl cellulose, methyl
cellulose and glyceryl monostearate have been used to fa-
cilitate production of a free flowing powder. However,
since some aids must be added at a large fraction, the
final product is a formulation with only a certain propor-
tion of fruit juice solids, and is affected by these addi-
--19--
. .
065
tives. For a juice, li~e blueberry juice, with relativelymild or subtle flavor, spray drying with or without drying
aids has not attained free-flowing powder-production.
Listed below are the prior art disclosures of which
the applicant is aware:
Selzer, E. and Settlemeyer, J.T., "Spray Drying of Foods",
Adv. Food Res., No. 2:399-520.
Anon, "New Orange Juice Powder", Food Eng'g, No.
25(1):186, 1953.
Burton, L.V., "Hi-Vacuum Technics for Drying Orange
Juice", Food Indust, No. 19(5):617-622, 738, 740,
- 742, 744, 1947.
Eddy, C.W., "Process of Drying Fruit or Vegetable Mater-
ials Containing added Methylcellulose", U.S. Patent
No. 2,496,278, February 7, 1950.
Elosdorf, E.W., "Process of Desicating Fruit Juices", U.S.
Patent No. 2,509,681, 1950.
Schwarz, H.W., "Dehydration of Heat Sensitive Materials",
Ind. Eng. Chem, No. 40:2028-2033, 1948.
Sluder, J.C., Olson, R.W., and Kenyon, E.M., "Production
of Dry Powdexed Orange Juice", Food Technol, No.
1:85-94, 1947.
Tammern, P.T., "Vacuum Evaporation of Fruit Juices", Dutch
Patent No. 64,132, 1949.
-20-
~;~7;~ i5
As mentioned above, prior art has not served to pro-
duce a free flowing product in powder form and yet attain
the subtle flavor of a fruit such as blueberries, particu-
larly due to the necessity for additives to prevent caking
and/or aglommeration in the spray drying apparatus.
With reference to Fig. 1, the syrup runoff is attain-
ed at outlet pipe 26; this concentrated syrup constitutes
from approximately 50-60% of the mixture of fruit and su-
gar. It is then diluted with different ratios of water
and freeze-dried until the moisture content reaches from
1-2%. After freeze-drying, the resulting crystallines are
removed from the drying trays into which they had been de-
posited and are packaged in cans, jars, or plastic pouches
either preferably in a nitrogen atmosphere.
EXAMPLE I
Individually quick frozen wild (lowbush) blueberries
were mixed with granular sugar (sucrose~ and/or syrups
containing high sugar (fructose) content at different ra-
tios, by weight, of fruit to sugar. Twenty pounds of blue-
berries were used with the granulated sugar ratios and ten
pounds of blueberries with the sugar syrup mixture. The
following table (Table I-A) illustrates the kinds of su-
gar, and fruit to sugar ratios used.
Table I-A - Blueberry and Sugar Mixing Ratios
TREATMENT: Fruit and Sugar
No. Blueberry (lb.) Sugar (lb.) Type Sugar
1 20 20 1:1 sucrose,
granular
2 20 10 2:1 sucrose,
granular
3 20 6.7 3:1 sucrose,
granular
-21-
.
0~;5
(cont'd)
Table I-A - Blueberry and Sugar Mixing Ratios
TREATMENT: Fruit and Sugar
No. Blueberry (lb.) Suyar (lb.) Type Sugar
4 10 lO 1:1 high fructose
corn syrup,
Brix = 82
1:1 corn syrup,
Brix = 75
The temperature of the frozen blueberry fruit was -10 F,
and the soluble solids in the fruit juice was 12%. The
fruit and sugar or syrup were mixed thoroughly, placed in
separate plastic tubs and allowed to stand at a tempera-
ture in the range of 50-60 F.
The effect of mixing blueberries and sugar at differ-
ent ratios i5 presented in Tables I-B and I-C.
Table I-B Effect of mixing blueberries and sugar at dif-
ferent ratios on sugar content in blueberries
and syrup.
Blueberry
Soluble
Treat- Soaking Pro- Solids (%) Syrup Brix %
ment duration duct [Not
No. (hr.) temp. [Rinsed][Rinsed]
1 21 36F -- -- sugar, largely
undissolved
2 21 34F -- -- sugar, largely
undissolved
3 21 38F 21 18 45
4 21 50F 22 21.2 43
21 46F 24 21 38
-22-
.. . .
~: :
~;~7~ 5
(cont'd)
slueberry
Soluble
Treat- Soaking Pro- Solids (~) Syrup Brix
ment duration duct [Not
No. (hr.) temp. ~Rinsed][Rinsed]
l 28 58F 35.6 22 64, some un-
dissolved sugar
2 28 56F 33 27 48
3 28 42F 24 20.2 41
4 28 60F 31 27 43.6
28 58F 24 24 40
1 45 59F 47 27.6 62, some un-
dissolved sugar
2 45 59F 36.4 27.2 45
3 45 60F 25 23.6 34
4 45 60F 35 30 41.4
60F 32 31.8 40.4
When frozen blueberries were mixed with granular
sugar at the ratio of 1:1 by weight and allowed to stand
at temperature of approximately 50-60F for 45 hours, a
considerable amount of sugar added (approximately 25%) did
not go into solution and remained in a crystalline form.
At all tested mixture ratios from 1:1, 2: 1 and 3: 1,
by weight, fruit to granular sugar, and 1:1 of fruit to
similar weight of high fructose corn syrup (Brix = 82)
and corn syrup (Brix = 75) and allowed to stand at 60F,
a syrupping process took place where juices moved out of
the fruit and sugar molecules moved in and impregnated the
fruit.
~ ~'7~ O~S
Sweetened fruit from all treatments had a very plea-
sant sweet flavor, in addition ~o their distinct blueberry
flavor. All syrup produced had the distinct color and
flavor of blueberries.
Table I Final yield of sweetened blueberries and
syrup 45 hours aEter mixing blueberry
and sugar
Treatment Blueberry Yield Syrup Yield
No. (~) (%)
. . _
1 24.4 75.5 (contained undis-
solved sugar)
2 33 67
3 43.5 56.4
4 31.5 68.5
31.4 68.6
EXAMPLE II
Thirty pounds of individually quick frozen cultivated
(highbush) blueberries were mixed with ten pounds of sugar
and placed in a plastic tub. The plasti~ tub was then
placed in a water bath where water temperature was main-
tained at 130F for eight hours. The plastic tub contain-
ing the blueberry-sugar mixture was oscilated and the con-
tents jostled once, every 30-60 minutes, to further mix
the blueberries, sugar, and emerging syrup.
The soluble solids in the juice of the blueberries
was 10% and the temperature of the fruit when mixed with
sugar was 10F.
Eight hours after mixing, soaking in a water bath at
130F, and occasional rolling and shaking of the contents,
the syrupping process was terminated and the berries were
-24-
.
'7~ 5
separated from the syrup. Seventeen pounds of sweetenedblueberry fruit were recovered (42.5% of total mixture)
and the weight of the syrup was 22.6 pounds (56.6 of total
mixture). Soluble solids in the juice of the sweetened
berries were 20% and the Brix of the syrup was found to be
44o.
The fruit had a sweet and pleasant mild blueberry
flavor, and the syrup possessed a purple color which was
much lighter in density and had a milder blueberry flavor
when compared to syrup obtained from Example I; primarily
because cultivated blueberries initially, before treat-
ment, have this characteristic.
EXAMPLE III
Individually quick frozen wild blueberries (lowbush)
were mixed with sugar at different ratios by weight vary-
ing between one and five fruit to one sugar. The tempera-
ture of the frozen blueberries was -2F and the soluble
solids in the blueberry juice was 12%. The fruit and su-
gar were mixed well, then placed in plastic containers and
allowed to stand at room temperature (approximately 70-
80F) for fourteen hours. The syrupping process earlier
described in the previous examples took place in all the
fruit to sugar ratios here tested and the results of sol-
ids contents in fruit and syrup are listed in the follow-
ing table:
Mixture Ingredients weight (gm) Blueberry Syrup
Ratio Blueberries Sugar Soluble Brix
Solids (%)
1:1 1000 1000 31 49
2:1 1000 500 28 45
3:1 1000 333 23 38
-25-
.
~ ~7~ 5
(cont'd)
Mixture Ingredients weight (gm) Blueberry Syrup
Ratio Blueberries Sugar Soluble Brix
Solids (%)
. . .
4:1 lO00 250 21 33
5:1 1000 200 20 29
. _
~ ifferences were noted in flavor of the sweetened
blueberries, with fruit from the 3:1 fruit to sugar ratio
by weight most preferred. They had a delightful balance
between sweetness and the delicate, but distinct flavor of
wild blueberries.
EXAMPLE IV
Three hundred pounds of individually quick frozen
blueberries were mixed with one hundred pounds of sugar in
a commercial Gemco tumbler/blender for five minutes. The
sugar coated blueberries were then placed in aluminum
trays with these approximate dimensions: 30" long x 18"
wide x 6" high. The sugar coated blueberries were placed
in the trays to a height of only four inches. The trays
were allowed to stand at room temperature of approximately
70F for approximately fourteen hours. During this period
the syrupping process took place.
The blueberries and syrup were then separated by plac-
ing the berries/syrup mixture on a sieve with openings of
1/8". The syrup collected weighed 176 pounds and had a
Brix reading of 38.
The sweetened blueberries were then placed in perfor-
ated plastic trays and dipped/immersed into a large water
tank filled with cold water (temperature approximately
-26-
.
.
1~7~0~i5
60F.) for a period of 20-30 seconds. They were then
placed on a vibrating perforated conveyor belt, rinsed
further with a stream of cold water, followed by a stream
of air. This served to remove a large portion of the sy-
rup and water from the surface of the fruit.
The weight of the sweetened blueberries was 174
pounds and the soluble solids in their juice was 24~. The
moisture content of the sweetened berries before rinsing
and surface air drying was 70% and 64~ after water rinsing
and surface drying.
The blueberries were then placed in ribbed trays 26"
long x 13" wide x 2": deep with approximately 12.4 pounds
fruit per tray. The trays were placed in a freeze-drying
chamber where the berries were freeze-dried under vacuum
of 400 microns Hg, oil temperature of 220F, platen tem-
perature of 180F to 220F, and a condenser temperature of
-30 to -35F. After eight hours, the product temperature
reached 90F. At this point, the vacuum was released ra-
pidly (in 90 seconds). Moisture content of the blueber-
ries was 22%. The berries were immediately removed from
the freeze-drying trays, separated, and allowed to cool.
This novel process produced a collapsed blueberry
product with very attractive appearance, intact but
slightly wrinkled, and distinct tart but sweetened blue-
berry flavor. The fruit was chewy, had pleasant feel to
the teeth and palate, and was not sticky to the touch of
the fingers or to each other.
EXAMPLE V
One hundred pounds of pitted frozen cherries were
mixed with thirty-three pounds of sugar, allowed to stand
-27-
~7~ 5
to syrup, drained, rinsed, surface dried, and freeze-dried
as described in Example IV for approximately ten hours.
Sixty~one pounds of cherry syrup with a Brix of 42 were
collected. The weight of the sweetened cherries before
drying was 51.7 pounds. The soluble solids of these sweet-
ened cherries before rinsing was 36.5g, and 3~% after rins-
ing with cold water. The moisture content of these cher-
ries was 74.6~ before rinsing. Twenty pounds of semi-
moist cherry product, with a moisture content of 17.6%,
were obtained.
The cherries had excellent flavor and were chewy with
a pleasant feel to the teeth and palate, having a collaps-
ed wrinkled appearance.
EXAMPLE VI
Semi-moist blueberries (20% moisture content) were
produced by the procedure described in Example IV. Com-
mercially available oil, Durlex 500 T was then used at
the rate of 0.25, 0.5, 1.0, 2.0 or 5.0% by weight to coat
five pound lots of the blueberries. The oil, at 70F, was
placed in a stainless steel pail. The pail was rotated to
allow the oil to coat the inside walls and bottom of the
container. Five pounds of the processed blueberries were
then placed into the pail and shaken, rolled and mixed
repeatedly in the container until uniformly coated with
the oil.
The oil coating enhanced the flowing and appearance
characteristics of the blueberries. When applied at 0.25
to 1.01 (oil to fruit by weight) it had no noticeable
residue on the surface of the fruit. None of the tested
ratio 0.25 to 5.0% by weight had an apparent effect on the
flavor of the product.
-28-
1~7;~ iS
While the invention has been described by reference
to specific examples and embocliments, it is limited only
by the scope of the appended claims.
-29-
~'~,7;~ iS
S~PPLEMENTARY DISCLOSURE
The principal disclosure mentions that the pro-
cess for producing a swee~ened dried frult product
inc]udes, freeze-drying in a vacuum atmosphere, the
fruit which has been rinsed to remove surface sugar
and/or syrup from outside the fruit.
It has now been found that this s-tep can be
carried out by vacuum-drying instead of freeze-drying
to produce a similar semi-moist fruit product. This
can be accomplished by vacuum-drying the fruit in
a vacuum chamber, in which case, the invention will
achieve a "collapsed" shape and texture of the semi-
moist frui-t.
Throughout the principal disclosure, vacuum is
applied in freeze-drying chamber 34. In accordance
with the supplementary disclosure, this chamber 34
is a vacuum-drying chamber. Additionally, when the
fruit is frozen and held to be dried to moisture
levels of (10-40~) subject to end-use, this takes
place by vacuum-drying.
It has a]so been found that the present invention
is applicable to the preservation of cranberries and
therefore also relates to the preserved product
obtained thereby.
The present invention, therefore, provides an
improved cranberry product produced by a novel pro-
cess r by controlling the moisture content of the
product and sweetness of the cranberry product, and
retaining therein the natural color and flavor of
the fruit and in fact enhancing the fruit-flavor and
texture, and by minimizing residual surface moisture
-thus minimizing the energy-expenditure through vacuum
drying and freeze-drying,b~th drying being accomplished
with a sudden release of vacuum over a controlled
-30-
1~7~
period, thus providing a cranberry product substan-
tially comparable to those of the principal disclosure
but which is unusual in appearance, taste, shelf life,
feel and touch to one s hand and palate.
Further, the present invention in conformance
with what is set forth above, concerns a process and
product produced -thereby, in which sweetened dried
fruit has a moisture range from 10% to 40~ including
rupturing or slicing fresh or fr~zen cranberries to
expose the fruit interior, coating the sliced cran-
berries with sugar or high fructose corn syrup and
achieving an osmotic sugar exchange within the fruit,
thus producing a sugared fruit and fruit syrup. The
process further includes separating the syrup from
the fruit, rinsing the sugared fruit sufficient to
remove surface sugar and/or syrup from the fruit,
rinsing the fruit, air-drying the fruit and vacuum
drying or freeze-drying the fruit, and suddenly
releasing the vacuum over a period of within 1 to
2 minutes to collapse the fruit to a relatively
wrinkled, solid chewy and palatable condition.
The sugared fruit syrup is diluted with water,
freeze dried whereby a crystalline flavoring product
is produced. In conformance with that set forth
above, a cranberry flavoring product is produced which
is usable as a cooking ingredient in combination with
other foods and mixtures.
It was found that the runoff from the sugared
cranberries when reduced to a moisture content of
from 4-9~; as will be demonstrated in the example
below, the product comprised a taffy-like consistency.
Thus combination flavoring and/or candy product was
produced. The product has an excellent cranberry
color and a distinct tangy and sweetened cranberry
flavor. The product can be used as a chewy, energy-
-31-
s
providing f]avorfu] natural-ingredient candy and/or
as a sweetener where the cranberry flavor and co]or
are desired.
Likewise, i.n the case of blueberries and/or
cherries, as described in the examples, below, the
runoff syrup of these products can be moisture-
controlled to produce the taffy-like consis-tency for
the purposes mentioned.
Additiona].ly, the blueberry, cherry and cranberry
sugared flavoring products can be used a]one or in
combination, with each other or with still other
fruits. For example, it is contemplated to be within
the scope of -the combinations to use:
blueberry/cherry; b].ueberry/cranberry; blueberry/
cherry/cranberry; cherry/cranberry; and blueberry/
cranberry.
As has been described in detail in the principal
disclosure, blueberries and cherries were processed
utilizing App].icant's disclosed apparatus and
procedures. Cranberries, outside of the obvious
differences of co].or and taste, include a relatively
thick waxy skin which must be penetrated i.e. ruptured
or sliced in order to gain access to the cranberry
fruit cavity and inner structure. Accordingly, a
difference between the supplementary disclosure and
Applicant's principal disclosure is that the cranberry
fruit because of physical differences, is ruptured
or sliced; after a preliminary screening and separa-
tion of damaged fruit, vines and/or removal of
extraneous material.
After rupturing through puncturing or slicing
is accomplished, cranberries are sugared, using either
sucrose, granular sugar, high fructose corn syrup
etc., by osmo-tic transfer or exchange between liquid
in the fruit and the sugar; next the fruit is
-32-
~ ~'7~V~iS
separated from the fruit-syrup produced during
sugaring; next: the syrup is washed off the fruit to
reduce stickiness -then free surface moisture is blown
off by an air stream which materially reduces vacuum
drying and/or freeze-drying times and the attendent
costs; next, the fruit is dried by vacuum-dryingand/
or freeze-dried under a vacuum, and with the very
rapid release of vacuum (within 1 to 2 minutes), the
cranberries, just as in the case of blueberries and
cherries, achieves a "collapsed" ;shape and texture
of a semi-moist fruit. During vacuum drying, about
in. Hg. is used, or in freeze-drying about 400
to 1200 microns Hg. of vacuum is utilized.
The ratio of the cranberries may range from 1
to 5 parts of fruit to one part of sugar. The pre-
ferred ratio is about three parts of fruit to one
part of sugar. Alternately the ratio of two parts
fruit to one part of sugar. The sugar may comprise
various types such as sucrose, fructose corn syrup
or dextrose, taking both granular and/or liquid forms
or both.
The ruptured or sliced fresh natural or frozen
cranberries are mixed with the suitable sugar or
sweetener in a tumbler or mixed in any other suitable
manner; next syruping proceeds in a soaking tank with
agitation up to about 12 hours (depending on fruit
temperature) when held at conventional room
temperatures ranging from about 70F to 80F. Heating
up to 140F can be applied to accelerate the syruping
process. Further, gentle vibration or oscillation
of the soaking tank may be provided to the soaking
tank to cause liquid and cranberry oscillation and
enhanced mixing. The Brix scale reading for the
sugared syrup derived from the cranberries will reach
from 35-40 Brix while the Brix scale reading for the
solids inside the cranberries range from 12 to 31
,-
~ ~7i~(~65
Brix, preferably 19.9 to 33 Brix.
After the desired Brix reading is attained, the
syrup is strained off the cranberries and the
sweetened runoff i.s uti.lized as is, or freeze-dried
to taffy-like consistency, or further dried to a crys-
ta].ine form, i.e., as a je~.ly flavoring or a pancake
syrup componen-t etc.
Next the sugared cranberries are rinsed under
a cold, rinse-water jet sufficient to remove excess
syrup off th~ fruit. The rinse water temperature
can range from 40-70F and serves the purpose of
both removing the syrup and pre-cooling the cran-
berries to subsequent freezing and/or dryi~g.
Although use of a cold water jet is contemplated,
immersion rinsing is al.so feasible. After rinsing,
the use of air knives or air jets are contemplated
to promote further removal of extraneous surface
moisture. The air removal of water reduces the total
water content of the cranberries by as much as 7-9%,
which enhances economic commercial production of the
dehydrated cranberries through reduced energy consump-
tion in vacuum and freeze-drying.
The cranberries can then be either IQF (indivi-
dual quick frozen) and held in conventional cold
storage until vacuum or freeze-dried or used immedi-
ately. Sweetened, rinsed and surfaced-dried cran-
berries are then dried up to a moisture content of
between 10-40% level, and preferably between 12% to
19% by weight.
Next during both vacuum-drying and freeze-drying,
under vacuum conditions of either 30 inches Hg or
400-1200 microns Hg, respectively, the vacuum con-
dition is suddenly terminated (within 1 to 2 minutes).
Just as in the case of blueberries and cherries, the
-34-
.,
~7;~
evacuated cranberries are produced in the desired
form, appearance, and touch and feel to the hand and
the palate. During release of vacuum, the drying
chamber can be simu]taneously purged with either air
or nitrogen. Preferably, -the cranberries are then
coated with an anti-caking agent to allow for free
flowing of the dehydrated cranberry pieces.
In summary, the invention entails the manufacture
of sweetened semi-moist fruit products and particular-
ly cranberry products. In this invention, liquids
from fruits are leached out and sugar molecules are
impregnated or transferred into the fruit parts and
cells by an osmotic syruping process. In syruping,
fresh or frozen cranberries, blueberries of the low-
bush and highbush types and cherries were mixed with
sugar at different ratios. The fruit sugar mixture
is allowed to stand and syruping occurs, i.e., where
fruit juice defuses out of the fruit and sugar mole-
cu]es dissolve in the emerging liquid and then migrate
into the fruit. The syruping process is accelerated
by regulating temperature and adding mixing-movement
to the fruit/syrup mixture. At a specific end pointj
the syrup and sweetened fruit are separated. For
example, when the Brix scale of the syrup reached
35-40 Brix and soluble solids in the juice of the
sweetened cranberries ranged from 12-31 Brix, the
sweetened cranberries and syrup is separated. Excess
adhering syrup is removed from the sweetened cran-
berries by washing or rinsing with cold water. Free
water on the surface of the sweetened fruit is then
removed by subjecting the fruit to shaking/vibrating
movements and to jet air blasts. The fxuit is then
frozen and held frozen and then vacuum-dried or
freeze-dried to moisture levels of (10-40%) subject
to end use. The vacuum used in either vacuum-drying
or freeze-drying at either 30" Hg or 400-1200 microns
Hg is released suddenly, from between 1 to 2 minutes.
':
' .~
~7~
The fruit is then coat-ed with anti-caking materia]
(such as Durkex 500 , ca]cium stearate, Cantab
or others), and packed in various size and type
containers.
EX~MPLE VII
Frozen blueberries were mixed with sugar at a
ratio of 3 blueberries to 1 sugar by weight as
described in Example III. After reaching equilibrium,
t:he sweetened fruit was separated from the syrup,
placed in a wash tank (K-10 washer by Key Technology
of Milton Freewater of Oregon) where it was washed
with cold water (40-50F), the blueberries were then
p]aced on a vibrating shaker/mover (ISO-FLO de-water-
ing shaker by Key Technology) where they were further
sprayed with fresh water (40-50F) to further remove
adhering syrup, then passed beneath air jets for sur-
face water removal from the rinsed fruit. The
sweetened, washed, rinsed air dried fruit was then
individual]y quick frozen (IQF) in a freezing tunnel
(Frigoscandia ~ Flow-Freeze freezing tunnel, of
Frigoscandia Con-tracting Inc., Bellevue, Washington)
where they were frozen to -15F. The frozen fruits
were then held in regular commercial cold storage
at -10F.
Twenty-eight pounds of the frozen sweetened fruit
having a soluble solidsreadings of 29 Brix in the
juice was then vacuum dried in a vacuum tumb]er dryer
(Paul O. Abbe Rota Cone Vacuum Dryer of Paul O. Abbe,
Inc , Little Fal]s, New Jersey). Temperature of the
blueberries was 0F, and the temperature of the oil
circulating between the dryers' jacketed walls were
set at 150F, and the drying cone rotated at 5 RPM
(rounds per minute). Vacuum was measured at 30 in.
Hg. The following table illustrates the vacuum-drying
conditions:
-36-
7;~i5
Time Blueberry Oi]/Drum Drum Drying Oi]
e]apsed temperature temperature RPM Vacuum Pressure
Start 0 F 150 F 5 0 in Hg. 0 Psi
30 mins. 60 F 200 F 5 30 30
180 mins. 88 F 200 F 5 30 30
240 mins. 88 F 200 F 5 30 30
* Drained/removed free juice = 8.28 lbs., Brix = 28,
temperature = 60 F.
After 240 minutes of vacuum-drying at 30 in.
Hg., the vacuum was released suddenly ~in less than
2 minutes) and the semi-moist blueberries were then
removed from the dryer and allowed to cool to room
-temperature. The blueberries were chewy, had a good
flavor, collapsed appearance, were free flowing and
shelf stable. The amount of semi-moist blueberries
were 7.87 pounds, representing a yield of 28.1% from
the initial amount of frozen, sweetened blueberries.
Moisture content was 18%.
EXAMPLE VIII
Frozen blueberries were sweetened with high fruc-
tose corn syrup (HFCS) at a ratio 2 blueberries to
1 HFCS by weight as described in Example 1. When
the soluble solids of the sweetened blueberries
reached 27F Brix, they were then separated from the
syrup and rinsed as described in Example VII. The
sweetened, rinsed blueberries were chilled to a
temperature of 26F, then vacuum-dried as described
in Example VII above. The following conditions were
attained:
-37-
1'~7~
Time Blueberry Oil/Drum Drum Drying Oil
elapsed temperature temperature RPM Vacuum Pressure
Start 26 F 200 F 5 30 in Hg. 30 Psi
20 mins. -- 200F 5 30 30
decreased
-to 150F 5 30 30
140 mins. 70 F 150 F 5 30 30
* Removed free juice = 0.71 lb., Brix = 40 ,
temperature = 86 F.
After 140 minutes of vacuum-drying under the
aforementioned conditions, the amount of semi-moist
blueberries recovered was 6.86 pounds of 37.1% of
the sweetened blueberries used, and had a moisture
content of 24%. The dehydrated blueberries had
exce]lent blueberry flavor, but were slightly sticky
to the touch.
EXAMPLE IX
27.65 pounds of frozen sliced cranberries were
sweetened with sucrose (granular sugar) as described
in the earlier examples, at a weight ratio of 3
portions of cranberries to 1 portion of sugar. The
cranberries were sweetened, as described in earlier
examples, until their soluble solids reached 31% Brix,
and thereafter were separated from their syrup,
washed, rinsed and chilled. They were then vacuum,
tumbled dried under the following conditions:
Time Cranberry Oil/Drum Drum Drying Oil
e]asped te~erature t ~e~ RPM Vacuum Pressure
Start 15 F 200 F 5 30"Hg. 30 Psi
*15 mins. -- 200F 5 30"Hg. 30 Psi
reduced
to 150 F
**90 mins;
210 mins. 66F 150F 5 30"Hg. 30 Psi
585 mins. 120 F 200 F 5 30"Hg. 30 Psi
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.,
, ~
iS
"*" - drained/removed free juice = 0.8916, Brix = 33 ;
temperature = 72 F.
"**" - at 90 minutes, the cranberries in the drum
were checked and found to be very moist.
The vacuum was released at the end of 585
minutes, suddenly within 1-2 minutes. The cranberries
were removed from the drum, they were found to be
semi-moist, had an excellent flavor and were sweet
and tangy. The product was chewy in texture, pleasant
-to the pa].ate, and was shelf stable. The final
product of cranberries weighed 8.13 pounds, repre-
senting a 29.4% from the sweetened, rinsed cranberries
and had a moisture content of 12% by weight.
EXAMPLE X
Frozer. cranberries were thawed to temperature
of 25F, then s]iced and sweetened with HFCS at a
ratio of 2 cranberries to 1 HFCS by weight. The
sweetened cranberries, when their soluble solids
reached an average of 21.4 Brix, were separated from
the syrup, washed, rinsed with fresh water, and indi-
vidually quick frozen (IQF). They were then placed
in ribbed trays and freeze-dried as described in
Example IV above. One thousand and five pounds of
IQF sweetened cranberries were used. Their moisture
content was 73.38% by weight, and the trays were
uniformly filled with an average of 9.75 lbs. of
cranberries per tray. After a drying cycle of 8
hours, the vacuum was released suddenly, being
repiaced by air between 1 to 2 minutes. Three hundred
and ten pounds of semi-moist cranberries were pro-
duced, representing a yield of 30.85% from the
sweetened and rinsed cranberries, and they had a mois-
ture conten-t of 20.08% by weight.
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7~ ;5
The novel cranberry product had an attractive
appearance, possessed excellent cranberry flavor,
was tart and tangy and was sweet to the palate. It
was chewy and had a p]easant Eeel to the teeth, mouth
and palate. The product was shelf stable and free
flowing.
Coating the semi-moist cranberries with 0.5%
Durkex 500 TM, as described in Example VI, above,
further enhanced the appearance and flowability of
this novel cranberry product.
EXAMPLE XI
Frozen cranberries were sliced as in the previous
example and mixed with chopped orange peels at the
ratio, by weight, of 95% cranberries to 5% orange
peel. The cranberry and orange peel mix was then
sweetened with HFCS, separated from the syrup, washed,
rinsed individually quick frozen, then freeze-dried
as described in the previous example. After freeze-
drying in a vacuum, vacuum was suddenly replaced by
air from 1 to 2 minutes. The soluble solids of the
cranberry/orange peel mix after rinsing was 23% Brix,
and their moisture content before drying was 73.09
by weight.
After freeze-drying, the moisture content of
the novel semi-moist cranberry/orange was 18.77% by
weight. The product had a delightful flavor of
sweetened tangy cranberries, accentuated by a trace
of orange flavor and a chewy texture providing a
pleasant taste and feel. It was shelf stable and
did not require freezing or refrigeration for storage.
EXAMPLE XII
Sliced, individually quick frozen cranberries
were a]lowed to thaw, then were sweetened with HFCS
-40-
~ ~7~ ;5
(hlgh fruc~ose corn syrup) at a ratio of 2 cranberries
to 1 ~-IFCS by weight; the sweetened cranberries were
t}.en sep~rated from the syrup, washed, rinsed and
frozen. Their so]uble solids averaged 19.9 Brix.
Their moist:ure content was 76.52g6 by weigh-t. The
sweetened cranberries were then freeze-dried as
described in Example X, above, to an intermediate
moisture oE 19.149~ by weight i.e., vacuum was replaced
by air, suddenly from between 1 to 2 minutes.
The semi-moist cranberries had excellent flavor
and were chewy in texture and had a wrinkled collapsed
appearance.
EXAMPLE XIII
Cranberry syrup resulting from Example XII was
fried as is or after dilution with water at ratios
of cranberry syrup to water at 2 to 1, and 1 to
by volume. Three, three-hundred milliliters of the
syrup (undiluted and diluted) were placed in three
round procelain pans to a depth of approximately
1/2 inch. The pans were placed in a blast freezer
(at -28C) for 45 minutes. The partially frozen syrup
was then placed in a freeze-dryer for approximately
45 hours under vacuum of 0.10 mm and a condenser
temperature of -38 to -40C. No heat was applied
to the product during freeze-drying. The following
table presents data on weight of the syrup, dilution
factor, syrup s soluble solids ( Brix), and yield
of dried product.
Sample # Syrup Weight Syrup Brix Dilution Weight of
(gm) w/water dried product
(gm)
338.5 37.5 1:0 138.1
2 322.0 26.5 2:1 89.2
3 319.1 20.0 1:1 67.9
--41--
1~7;~()65
The novel freeze-dried cranberry syrup had a
taffy-like consistency, a moisture content of 4-9%,
exce]lent cranberry co]or, and the distinct tangy
but sweetened cranberry flavor. It could be eaten
as a candy or used for other food products where
natural cranberry flavor and co]or is needed.
EXAMPLE XIV
Cranberry syrup resulting from Example XII was
diluted with water at ratios of cranberries to water
by volume of 1 to 3, 1 to 5, and 1 to 10. The diluted
syrup was then b]ast frozen, then freeze-dried as
described in Example XIII. After 56 hours of freeze-
drying sweetened cranberry crystals were collected.
This nove] product had a moisture content of 1-2~,
was cranberry-red in color, and possessed a sweetened
but tangy cranberry flavor. The product is suited
for use in coloring and flavoring foods where natural
cranberry color and flavor are desired, i.e., pancake
syrup, jelly, etc. This novel product is shelf stable
and presents a great reduction in volume and weight
from the natural cranberry fruit.
It will thus be seen that the object set forth
above, among those made apparent from the preceding
description, are efficiently attained and, since
certain changes may be made in carrying out the above
method and in the article set forth without departing
from the scope of the invention, it is intended that
all matters contained in the above description shall
be ~interpreted as illustrative and not in a limiting
sense.
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