Background of the Invention
This invention generally relates to citrus-originating
products and processes for making them. More particularly, the invention separates
a citrus juice source into a permeate liquid and a retentate containing virtually
all of the pulp present in the citrus juice source. This pulp retentate is subjected
to diafiltration, which reduces levels of bitterants such as naringin and limonin
within the pulpy material, and the diafiltration retentate is processed as or into
useful pulp products and/or clouding agents which have blandness characteristics
Citrus fruits have long been recognized as valuable sources
of important nutrients. More recently, health benefits and disease retarding or
treating benefits of citrus sources have come to be more fully recognized as advantageous
and beneficial when ingested. Accordingly, there is a general belief that increasing
the intake of citrus-originating foods is a beneficial and important objective in
the overall scheme of human health.
Segments of the population are less than enthusiastic about
certain characteristics of citrus products, such as bitterness, acidity, and a thick
consistency. Concerns about these types of characteristics are perhaps most prevalent
when the citrus product or ingredient is grapefruit originating. Other citrus fruits
can present these types of concerns, including orange, tangerine and lemon fruits.
In terms of volume of juice and percentage of dislike in the juice-consuming population,
grapefruit products and non-traditional orange-originating products present both
the greatest challenge and the most promising potential. Heretofore, these resources
have been underutilized due to these types of characteristics of grapefruit sources
and non-traditional other citrus sources, which characteristics can be considered
objectionable to certain segments of the population.
Numerous approaches have been taken in the past which incorporate
various filtration and ion exchange technology in order to operate upon citrus juice
sources with a view toward preparing a variety of different products and byproducts.
These approaches typically do not substantially change the characteristics of or
operate on pulp components. It has long been known that citrus pulp can be separated
from citrus juice. Often, this involves removing pulp so as to provide a so-called
clarified juice. In those instances, the separated pulp is discarded, used in low-value
products such as animal feed, or is stored for reintroduction of some of it into
juice products which are formulated to have high pulp contents.
It will thus be seen that, in many instances, citrus fruit
pulp is not used in a high value manner. For this reason and others, citrus fruits
are not used to their full potential, and many valuable nutrients are not put to
use in a manner which directly benefits people. This is particularly true for separated
components which include the citrus pulp. There is accordingly a need for approaches
which allow a more complete realization of the potential of citrus fruits, and especially
of grapefruit sources and other currently under utilized citrus sources.
Also needed is a natural source of bland clouding agent
or pulp for use in juice products and other potential uses. Fulfilling these needs
with citrus sources would allow for pulp products and clouding agents which are
more nutritious than in the past and which are particularly economical.
US 5 202 142 discloses a process for the production of
cloudy juices with stable cloudiness from plant products in which the raw juice
is clarified in an ultrafiltration unit and is mixed as cold sterilized clear juice
with the filter residue of a crossflow filtration. Here the filter residue serving
as clouding agent is very finely crushed in crushing unit before being fed into
mixing device. Along with the filter residue stabilizing agents are also fed into
mixing device to prevent the agglomeration of the very finely crushed particles.
Through the totality of the measures according to the invention a high degree of
cloudiness stability of the cloudy juice is achieved.
Summary of the Invention
In accordance with the present invention, citrus fruit
sources are processed into pulp products which are relatively low in bitterness
attributes, and which can be reduced acidity as desired. These products include
a bland clouding agent or source of bland pulp. Each of these products is entirely
natural. The nutrients present in the citrus fruit source are effectively recovered
in one or more of the products. Included is diafiltration of a pulp-rich retentate
from filtration of a citrus juice supply or concentrated citrus juice supply. Bitterant
reduction results. Pulpy retentate from the diafiltration is especially bland and
can be further processed such as to reduce moisture levels.
It is accordingly a general object of the present invention
to provide improved citrus juice products and processes which are and/or Incorporate
bland pulp components.
Another object of the present invention is to provide improved
citrus fruit processing and products which improve the overall yield of citrus fruit
Another object of this invention is to provide improved
citrus juice pulp products which are incorporated into food and beverage products
without adding undesirable bitterness flavour notes.
Another object of the present invention is to provide an
improved bland pulp or clouding agent which is a retentate from a citrus pulp source
and processes for preparing and using same.
These and other objects, features and advantages of the
present invention will be apparent from and clearly understood through a consideration
of the following detailed description.
Brief Description of the Drawings
In the course of this description, reference will be made
to the attached drawings, wherein:
Description of the Preferred Embodiments
- Fig. 1 is a schematic representation of an embodiment of the invention which
can be used in preparing a debittered pulp which can be collected or added to a
juice product; and
- Fig. 2 is a schematic representation of another embodiment of the invention.
The present invention is directed toward citrus fruit originating
products and processes for making them. Citrus fruits include grapefruit, orange,
tangerine and lemon fruits. The invention is well suited for use with grapefruit
sources and for low value orange, grapefruit and other citrus sources, as well as
for other citrus juice sources. At times, the citrus fruit which is discussed herein
is grapefruit, and its primary citrus bitterant, naringin. The invention successfully
addresses concerns regarding perceived negative attributes of grapefruit-originating
products. The principles of this invention also are applicable to other citrus fruit
sources, including juice extracted from the peel and pulp fractions of citrus fruits.
When such sources are orange sources, its primary bitterant to be contended with
is limonin. Bland citrus-originating clouding agents and pulp products with reduced
negative attributes are provided.
With reference to Fig. 1, a citrus juice 11 is the originating
material. It can be, for example, a grapefruit juice, a concentrated grapefruit
juice, or an orange or grapefruit peel juice or a pulp wash product from orange
or grapefruit processing. A typical juice source would have a soluble solids or
sugars level of 5-15° Brix. As is well-known in the art, such Brix levels will
be considerably higher as the juice source is provided in a more concentrated condition,
so that these solids or sugars correspondence levels can be as high as 60°
Brix and above.
Citrus juice 11 will have a level of natural bitterant(s)
which varies with the originating fruit. Typical ranges are between about 500 ppm
and about 1200 ppm naringin for grapefruit sources and about 5 ppm to about 100
ppm limonin for orange sources. Supply 11 will also have a naturally occurring acidity
level, typically primarily citric acid, of between about 0.70 weight percent to
about 1.20 weight percent. Citrus juice source 11 flows into a membrane filtration
unit 12. Typically unit 12 will incorporate an ultra filtration membrane and/or
a micro filtration membrane. A typical ultra filtration membrane of this type will
have a minimum pore size of about 30 Angstroms, which generally equates to a Molecular
Weight Cut Off (MWCO) of about 2000. A typical ultra filtration membrane maximum
pore size is about 1000 Angstroms (0.1 micron), which generally equates to 100,00
MWCO. A typical micro filtration membrane of this type will have a pore size range
of between about 0.1 micron and about 1.0 micron.
Filtration unit 12 separates the flow from the citrus juice
source 11 into a permeate which moves into : transfer member 13 and a retentate
which moves into a transfer member 14. This permeate continues to have a Brix level,
a bitterant (e.g., naringin or limonin) level and an acidity level approximating
those of the citrus juice source 11. It is substantially devoid of any pulp or clouding
solids. The retentate from filtration unit 12 retains virtually all of the natural
solids or pulp material. This retentate can be generally referred to as citrus pulp
solids. It also has the Brix level, bitterant level and acidity level which approximate
or are greater than those of the citrus juice source 11. This retentate contains
the suspended solids such as proteins and fibers and high molecular weight carbohydrates
such as pectins associated with citrus cloud.
A diafiltration unit 15 receives the citrus pulp retentate
from the transfer member 14. As is generally known in the art, a diafiltration unit
accomplishes filtration through the use of a washing system which applies a liquid
to the filtration media. It has been found that such an approach allows soluble
components within the citrus pulp retentate to be dissolved so as to pass through
the filtration media, while the pulp solids collect as a diafiltration retentate.
In an illustrated arrangement, between approximately 75% and 90% of the soluble
components find their way into the diafiltration permeate and to transfer member
16. It has been found that, by proceeding with this approach, most of the following
components find their way into the diafiltration permeate: naringin limonin or other
bitterant(s), sugars, acid, vitamins and nutrients including vitamin C, minerals
and the like. Conversely, only between about 5% and 25% of these same components
(including naringin or limonin) remain in the diafiltration retentate, which passes
to a transfer member 17.
This diafiltration retentate has been found to be an all-natural
bland clouding agent. It can have a very low bitterant concentration. For grapefruit
processing, a naringin level of between about 20 ppm and about 100 ppm is attainable.
Higher naringin levels can be selected, as the need dictates, up to about 200 ppm,
for example. An example of a useful naringin level can be between about 50 and 180
ppm, or between about 80 and 150 ppm, often not greater than about 120 ppm. For
orange products, the limonin level can be reduced to levels below 5 ppm.
Acidity reduction also is achieved by the diafiltration
system. This diafiltration retentate clouding agent material has an acidity level
of not higher than approximately 0.3 weight percent. Higher acidity levels can be
selected, such as high as about 0.5 weight percent, based upon the total weight
of the retentate. Its sugar content is relatively low, this bland clouding agent
being at about 2-3° Brix.
This all-natural bland clouding agent material passes from
the collection vessel 21 into receptacle 18. It has been found to be suitable as
a source of pulp or "cloud" for a filler juice or a stand-alone juice product. It
has been found that this product can be used as an additive, such as through transfer
member 20, for juice products. As such an additive, it provides an all-natural bland
clouding agent which has been found to be instrumental in providing visual cues
which allow a consumer to identify the citrus source, even for a juice which has
a very low bitterant level and has a reduced acidity level.
The relative percentage amount of diafiltered materials
varies with the particular type of equipment within which the diafiltration is carried
out. This also varies in accordance with the volume of liquid, typically water,
which is used in the diafiltration equipment, such as from wash source 19, as well
as the number of diafiltration washings. More particularly, the volume of wash liquid
from source 19 will be from about 2 times to about 5 times the volume of citrus
pulp retentate entering the diafiltration unit 15 from the transfer member 14. It
has been found that suitable results can be achieved in a typical large-scale diafiltration
unit if the wash volume is between about 2.5 and about 4 times the volume of the
citrus pulp entering the diafiltration unit 15. Preferably, the wash liquid is at
a temperature of between about 80° F. and about 130° F. (about 26°
and about 55° C.).
Depending upon the relative amount of water within the
all-natural bland clouding agent, it may be desired to reduce its water level in
order to provide a somewhat more concentrated clouding agent. Typically, the water
concentration of the pulpy retentate at area 21 is approximately 80 to 90 weight
percent or less. In this instance, the all-natural bland clouding agent will move
from area 21 to a separation apparatus 22 which is suitable for separating liquids
and solids. A typical separation apparatus is a filter press. Other options include
a centrifuge, a decanter, or a vibrating press. It can include traditional crossflow
filtration filters or devices using vibrating filter technology. Passage of the
all-natural bland clouding agent material through the separation apparatus 22 forms
a pulp wash byproduct 23 and an all-natural bland concentrated pulp or clouding
agent 24, typically having a water content of approximately 70 to 80 weight percent
or less. This concentrated product has properties similar to the all-natural bland
clouding agent material 18, as adjusted by the reduced water level. If desired,
this could be added to a juice product.
With further reference to Fig. 1, the permeate flow or
pulp byproduct flow from the diafiltration unit can be moved from the transfer member
16 to a debittering and/or deacidifying section 25. This flow contains substantially
all of the nutrients from the flow into the diafiltration unit. This passage can
be directly into the section 25 or into transfer member 13 before it enters debittering
and/or deacidifying section 25. At section 25, one or more debittering columns 26
are included. This debittering line is as generally known in the art and results
in substantial reduction of naturally occurring bittering agents. Typically, adsorption
resins are used in section 25. Commercial adsorption systems are available for use
in section 25. Examples include systems incorporating ion exchange resins such as
cationic polystyrene adsorbent resins, cationic acrylic adsorbent resins, polyamide
resins, anionic polystyrene copolymers which release chloride groups, basic anionic
polystyrene resins having quaternary ammonium active groups, and other suitable
resins or other adsorbents which are known and available in the art for use in these
types of systems. Examples of adsorbents and ion exchange resins for debittering
and/or deacidification are found in U.S. Patents No. 4,297,220, No. 4,439,458, No.
4,514,427 and No. 5,817,354.
For grapefruit sources, the primary bittering agent removed
from the all-natural bland clouding agent material is naringin, which is the predominant
flavanone glycoside that naturally occurs in grapefruit. Compounds falling within
the limonoids group are also found in citrus fruits, including limonin and nomilin.
In orange sources, the primary bittering agent removed is limonin. Other bittering
agents can be removed here. The non-bitterant flavanone glycoside hesperidin is
predominant in orange and tangerine citrus fruits. These types of bitterants are
substantially reduced within the debittering columns and during the diafiltration
according to the invention.
With particular reference to grapefruit, when a substantial
quantity of the naringin content is removed from the all-natural blanding agent
material, the result is a grapefruit juice pulp which is substantially less bitter
than unprocessed grapefruit juice pulp. When the naringin level is especially substantially
reduced, it can be difficult to identify the resultant pulp materials as grapefruit
It will be appreciated that the acidity of the citrus juice
source 11 can be reduced. In these instances, the section 25 includes one or more
deacidification columns 27 and receives juice flow from transfer members 13 and
16 (when provided). Deacidification equipment represented by column 27 is generally
known. It has the ability to significantly reduce the acid content of citrus juices.
Many citrus juices have a natural acidity of at least about 0.5 weight percent.
A typical acidity content after passage through column 27 and into a receptacle
28 will be between about 0.3 and about 0.9 weight percent. A typical range is between
about 0.4 and about 0.8 weight percent acid, typically as citric acid.
Referring now to Fig. 2, with this embodiment, some or
all of the all-natural bland clouding agent is added to the clear juice from a debittering
and/or deacidifying section 55. If desired, this addition can be made within a receptacle
of cloudy juice product 58, as generally illustrated. Excess all-natural bland clouding
agent can be collected in receptacle 48, if all is not to be directly used to form
the cloudy juice product 58.
The cloudy juice product 58 is useful as a cloudy filler
juice or as a cloudy stand-alone juice. When the latter originates from a grapefruit
source, it is a unique grapefruit juice product which is easily recognized as a
grapefruit juice while avoiding what a segment of the population finds objectionable
in unprocessed grapefruit juice, especially naringin content and also acidity, while
still maintaining virtually the same level of pulp within the grapefruit juice.
High pulp juice products also can be provided. With this aspect of the invention,
the pulp itself is not a source of objectionable levels of bitterants or acidity,
but instead the bland pulp or clouding agent is reunited with the modified liquid
component flowing from section 55. When the product is to be a cloudy filler juice,
usually a lesser quantity of pulp can be added than for a cloudy stand-alone juice.
Generally speaking, in order for a juice to be properly
labeled in accordance with governmental regulations, it must be organoleptically
recognizable or identifiable as that juice. Typically, taste tests are instrumental
in determining whether or not a juice is recognized as the particular juice, for
example grapefruit juice. For example, a clear filler juice having a naringin level
in the 120 ppm range (or in some cases lower) and an acidity in the 0.8 weight percent
range (or in some cases lower) and a Brix value in the range of 10° Brix may
not be recognized as grapefruit juice by a majority of taste panelists, whereas
adding the all-natural bland clouding agent to this formulation at a level of at
least about 5 weight percent, based upon the total weight of the filler juice, results
in a cloudy filler juice which consistently has been organoleptically identified
as grapefruit juice by a majority of taste panelists.
As an additional example, when this same type of grapefruit-originating
cloudy filler juice is used in making a blended juice product, with key juice sources,
the fact that the product includes grapefruit juice as one of the juices was not
readily detectable. This provides the advantage of providing a filler juice which
is a true natural juice without the at times perceived negative characteristic citrus
juice flavor and especially the bitterness associated with it. Such a product has
the nutritional positives of citrus juice without negatives which are perceived
by certain segments of the population.
A citrus juice source 41 flows into membrane filtration
unit 42, with the permeate flowing out to transfer member 43 and the citrus pulp
retentate flowing to transfer member 44 and into diafiltration unit 45. Wash source
49 flows into the diafiltration unit 45, while transfer member 46 receives the diafiltration
permeate and transfer member 47 receives the diafiltration retentate. When provided,
debittering columns 56 and/or diafiltration columns 57 of the section 55 perform
substantially as described above with respect to section 25.
With more particular reference to the diafiltration units
15 and 45, a number of different units can be used. Included are those incorporating
tubular ultra filtration membrane cartridges. Others are of types which use hollow
fiber and ceramic ultra filtration and/or micro filtration cartridges.
Illustrations of the disclosure herein are provided in
the following Examples.
Grapefruit concentrate was passed through a hollow fiber
micro filtration unit. In order to debitter the juice product flow, the permeate
therefrom is passed through a Koch debittering resin column. During debittering,
adsorption of the naringin onto the surface area of the resin material of the commercial
unit was carried out. The original naringin level was 735 ppm, and the juice permeate
was debittered to a naringin level of about 120 ppm.
The retentate from the hollow fiber micro filter unit was
added to 8 gallons of water, and the resulting slurry was circulated through an
ultra filtration Niro crossflow filtration unit, and 8 gallons of permeate were
removed. This profile was repeated four times until the soluble solids/sugars within
the retentate dropped below 1.0° Brix. The initial level was 10.87° Brix.
This diafiltration was found to be highly successful in
decreasing the naringin concentration from the original value of 735 ppm to a value
in the final diafiltration pulp material retentate of 86 ppm. This represented an
88% reduction in naringin levels, this having been accomplished with four equal-volume
(8 gallon) washings. The initial acid level was 0.88 weight percent. At the final
diafiltration, the retentate had an acidity of 0.11 weight percent. Analysis indicated
that a very large percentage of the vitamin C was removed during this diafiltration
and passed into the permeate. The initial flow into the diafiltration unit had a
vitamin C content of 25.89 mg/100 ml, and the final retentate from the diafiltration
had a vitamin C level of 3.02 mg/100 ml. A color analysis indicated that there was
some change in color, but not a great deal. For example, the flow into the diafiltration
unit was analyzed to have a so-called OJ Index of 31.2. After completion of the
diafiltration, the retentate had an OJ Index of 28.7. The "L" transmittance was
66.30 going in and 65.38 for the final retentate. The "a" transmittance going in
was -4.61, and the final retentate value was -5.14. The "b" transmittance was 18.83
before diafiltration and 12.04 after the last diafiltration.
After the second diafiltration wash, the initial naringin
level of 735 ppm was reduced to 223 ppm in the all-natural pulp material retentate.
After the third wash, the naringin level was reduced to 141 ppm, with the fourth
wash level being 86 ppm. The initial water wash temperature was 82° F. (27.8°
C.). Each subsequent wash was generally higher in temperature, the highest temperature
being 123.2° F. (50.7° C.). The average wash liquid temperature during
the diafiltration operation was 114° F. (45.6° C.). The resulting product
was an all-natural grapefruit-originating bland pulp material or clouding agent.
The approach of Example 1 was generally repeated. The feed
volume was 6 gallons of the retentate pulp material and 6 gallons of water for each
of 4 diafiltration washes. The water temperature ranged from 94° F. to 116.8°
F. (34.4° C. to 47° C.). Initial naringin level was 735 ppm. After the
first diafiltration wash, the naringin level in the retentate all-natural pulp material
was reduced to 295 ppm. After two washes, the level was 211 ppm. After three washes,
the naringin level was 153 ppm, and after four washes, it was 106 ppm.
Sugars or soluble solids level for the feed into the diafiltration
unit was 10.6° Brix. After final diafiltration washing, the level of sugars
or soluble solids in the retentate pulp material was 0.9° Brix. Initial acidity
was 0.88 prior to diafiltration. After the final diafiltration wash, the acidity
of the all-natural retentate pulp material was 0.12 weight percent. After the last
diafiltration wash, the vitamin C level of the retentate pulp material was reduced
to 1.40 mg/ml. Color values were an OJ Index of 28.2, a "L" transmittance of 66.03,
an "a" transmittance of -5.02, and a "b" transmittance of 10.51. This all-natural
grapefruit-originating bland clouding agent adds a desirable cloudy character to
any number of consumable products.
Another run was made generally along the lines of Example
1. This utilized a Niro separation skid with two Koch Super-Core modules. Cross-flow
diafiltration was used in the removal of solubilized naringin from the grapefruit
juice retentate. In this run, before making the first diafiltration water addition,
the retentate was concentrated by initiating the cross-flow without water addition,
the water reduction being from about 220 pounds to about 110 pounds, the reduction
designating the amount of water removed during this initial concentration step.
Thereafter, the 110 pounds of concentrated feed retentate were washed with 110 pounds
of water at about 120°F. (48.9° C.), followed by a second wash of 110
pounds, and then a third wash of 55 pounds of water at about 120° F. (48.9°
C.). Thus, the diafiltration was at 2.5 times the volume of the pulp material being
Initial naringin level was 750 ppm, and the final retentate
all-natural bland clouding agent or pulp material had a naringin level of 130 ppm.
The initial acidity level was 0.91 weight percent, and the final acidity level of
the diafiltered retentate was 0.24 weight percent. Initial Brix level was 11.28°
Brix, and the final level was 4.35° Brix of the diafiltered retentate pulp
material. Regarding color, the initial OJ Index was 30.9, and the final OJ Index
of the retentate pulp material was 30.7. The "L" transmittance was 67.55 initially
and 72.17 after diafiltration. The "a" transmittance was -4.65 initially and -3.83
after diafiltration. The "b" transmittance was 18.44 initially and 18.32 after diafiltration.
An all-natural grapefruit-originating bland clouding agent was provided.
A procedure as generally described with respect to Example
3 was followed. The initial concentration prior to diafiltration was 1.5 times reduction,
and 2 full volume diafiltration steps were carried out. The retentate starting material
prior to concentration was as in Example 3. After final diafiltration, the naringin
level was 274 ppm, the acid level was 0.33 weight percent, and the sugars content.was
4.87° Brix in the resulting retentate all-natural pulp material.
Taste tests were conducted on grapefruit juice products
in order to evaluate whether or not the particular grapefruit juice product was
identifiable as grapefruit juice. A control grapefruit juice was used in the taste
comparisons, the control juice having these specifications: 3.23 pH, an acidity
of 1.3 weight percent as citric acid, 10° Brix soluble solids, about 700 ppm
naringin, and a natural and untreated pulp concentration of 10.5 volume percent.
A grapefruit juice formulation "A" was prepared as described
herein to have the following specifications: 3.48 pH, an acidity of 0.82 weight
percent as citric acid, 7.5° Brix soluble solids, 118 ppm of naringin, and
a concentration of 12.5 volume percent of the all-natural bland pulp material according
to the invention.
Another grapefruit formulation "B" prepared as described
herein had the following specifications: 3.47 pH, an acidity of 0.78 weight percent
as citric acid, 9.9° Brix soluble solids, 125 ppm naringin, and a concentration
of 12.5 volume percent of the all-natural bland pulp material according to the invention.
Each participant was questioned if he or she had consumed
grapefruit juice within the last 30 days, this question being asked to distinguish
grapefruit "users" from "non-users". For the juice "A" test, 28.5% were placed in
the user category, and 71.5% were placed in this non-user category. For the juice
"B" test, 35% were placed into the user category, and 65% were placed in the non-user
category. Each person taste tested the control and the grapefruit juice "A" and
was asked if they would identify juice "A" as grapefruit juice. A total of 71.5%
identified the juice as grapefruit juice, and 28.5% did not. For juice "B", 70%
identified as grapefruit juice, and 30% did not.
A different grapefruit juice product, juice "C" was tested
in the same manner. This juice product had these specifications: 3.74 pH, 0.64 weight
percent acidity as citric acid, 9.8° Brix soluble solids, 125 ppm naringin,
and 12.5% of the all-natural bland pulp in accordance with the invention. This panel
had 22.5% grapefruit users and 77.5% non-users. 52.5% of the total respondents identified
this juice product as grapefruit juice, whereas 47.5% did not identify it as grapefruit
A further grapefruit juice formulation, juice "D" was subjected
to the same taste testing. It was a clear juice as made herein but contained no
pulp. Its specifications were as follows: 3.48 pH, 0.82 weight percent acidity as
citric acid, 10.1° Brix soluble solids, 123 ppm naringin, and no pulp (whether
untreated or blanded). This panel included 30% grapefruit juice users and 70% non-users.
A total of only 42.5% of the panelists identified juice "D" as grapefruit juice,
whereas 57.5% of the panelists did not identify this as grapefruit juice.
Another grapefruit juice formulation, juice "E" was taste
tested in the same manner. Juice "E" had these specifications: 3.48 pH, 0.80 weight
percent acidity as citric acid, 10.5°' Brix soluble solids, 120.7 ppm naringin,
and 3.8 volume percent of the all-natural bland pulp or clouding agent in accordance
with the invention. This panel had 25% users and 75% non-users, and 60% of the total
respondents identified this juice product as grapefruit juice, whereas 40% did not
identify it as grapefruit juice.
Further taste tests were conducted on grapefruit juice
products generally as in Example 5, except the ratio of grapefruit juice "users"
to "non-users" was selected to be 90 to 10, which is more in accordance with grapefruit
juice consumption in the U.S.A. Also, the control grapefruit juice was consistently
tasted after the formulation being evaluated. The control grapefruit juice used
in the taste comparisons had these specifications: 3.23 pH, an acidity of 1.30 weight
percent as citric acid, 10% Brix soluble solids, 642 ppm naringin, and a natural
and untreated pulp concentration of 10.5 volume percent.
Each participant was questioned if he or she had consumed
grapefruit juice within the last 30 days. For each test, 10% answered "yes", and
these participants constituted the "user" category. Those answering "no" (90%) made
up the "non-user" category for the following four formulations.
A grapefruit juice formulation "R" was prepared as described
herein to have the following specifications: 3.84 pH, an acidity of 0.84 weight
percent as citric acid, 10.1° Brix soluble solids, 118 ppm of naringin, and
a concentration of 5.0 volume percent of the all-natural bland pulp material according
to the invention. Each person taste-tested the juice "R" and then the grapefruit
control. Each was asked if he or she would identify juice "R" as grapefruit. A total
of 87% identified the juice as grapefruit juice, and 13% did not.
Another grapefruit formulation "S" prepared as described
herein had the following specifications: 4.47 pH, an acidity of 0.40 weight percent
as citric acid, 9.7° Brix soluble solids, 193 ppm naringin, and a concentration
of 5.0 volume percent of the all-natural bland pulp material according to the invention.
For juice "S", 67% identified the juice as grapefruit juice, and 33% did not.
A different grapefruit juice product, juice "T" was tested
in the same manner. This juice product had these specifications: 4.06 pH, 0.63 weight
percent acidity as citric acid, 9.9° Brix soluble solids, 174 ppm naringin,
and 5.0% of the all-natural bland pulp in accordance with the invention. 77% of
the total respondents identified this juice "T" product as grapefruit juice, whereas
23% did not identify it as grapefruit juice.
A further grapefruit juice formulation, juice "U" was subjected
to the same taste testing. It was a clear juice which was rather high in acidity
and naringin and contained no pulp. Its specifications were as follows: 3.85 pH,
0.81 weight percent acidity as citric acid, 10.8° Brix soluble solids, 129
ppm naringin, and no pulp (whether untreated or blanded). A total of 69% of the
panelists identified juice "D" as grapefruit juice, whereas 31% of the panelists
did not identify this as grapefruit juice.
An orange and cranberry juice blend was prepared which
incorporated the grapefruit cloudy filler juice made generally in accordance with
Fig. 2. This cloudy grapefruit filler juice had the following average specifications:
3.84 pH, an acidity of 0.80 weight percent as citric acid, 150 ppm naringin, and
4 volume percent of the all-natural clouding agent or pulp prepared as described
This cloudy grapefruit filler juice was concentrated to
59° Brix, after which it had a pH of 5.90. About 410 gallons of this cloudy
grapefruit filler juice concentrate were blended with about 180 gallons of orange
pulp wash concentrate of 65° Brix and 2.84 pH, about 130 gallons of orange
concentrate at 65° Brix and 4.02 pH, about 120 gallons of cranberry concentrate
at 47.7° Brix and 11.5 pH, an orange and cranberry flavor formulation, red
colorant, and about 320 gallons water. This prepared a concentrated orange cranberry
base product. A blended juice product was made from this base. An approximate 1000
gallon batch of such a blended juice product includes about 23 gallons of this orange
cranberry base, about 115 gallons of high fructose corn syrup sweetener, and about
865 gallons of water. This single-strength product has an acidity of about 0.5 weight
percent acid as citric acid, and is a juice product of about 13° Brix..
Prior to blending, the cloudy filler juice was identifiable
as grapefruit juice when at a single strength. In the single-strength blended cloudy
juice, the identifiable flavors were those of orange and cranberry and not of grapefruit.
Orange peels were shredded into pieces no larger than about
3/4 inch. The smaller peel pieces were combined with water at water/peel ratios
of 0.5/1 to 2.5/1. The water/peel slurry was pressed to separate the peel solids
from the peel liquor (juice). The raw peel liquor was centrifuged to separate out
a peel oil fraction and a sludge heavy phase from a peel juice having a Brix of
about 4 to 8 ° , with a total solids of about 4 to 10 weight percent. The peel
juice was processed through a membrane filtration system, and diafiltration was
carrie : out generally in accordance with Example 1. The primary bitterants removed
into the clarified peel juice are limonin, citrus flavonoids, and polyphenolic compounds,
the blanded peel or pulp solids (retentate fraction at 10 to 20 weight percent total
solids) being an all-natural orange peel originating clouding agent.
Pulp wash from orange juice processing at 4 to 7 Brix is
used as the originating citrus source for preparing an all-natural orange-originating
clouding agent by proceeding with a process in accordance with Example 1. Pulp wash
is processed through the membrane filtration system to produce a clarified fraction
(permeate) and a concentrated pulp fraction containing the suspended solids, high
molecular weight carbohydrates, pectin, fibers, as well as bitterants and soluble
solids present in the pulp wash feed. Through diafiltration of the retentate fraction,
the level of bitterants, sugars and soluble solids are reduced to about half of
the original level to produce the bland pulp solids fraction which is the base of
the natural cloud product. The primary bitterant for removal from the orange pulp
wash stream during this processing is limonin.