Note: Descriptions are shown in the official language in which they were submitted.
CA 02525716 2005-11-09
WO 2004/103131 PCT/US2004/016209
METHOD FOR LOW PRESSURE, LOW TEMPERATURE COOKING VIA THE
LINTONIZINGTM PROCESS
Cross Reference to Related Applications
[0001] This application claims the benefit of U.S. Provisional Application
No.60/472,547,
filed May 21, 2003 and U.S. Provisional Patent Application No. 60/533,699,
filed
December 30, 2003.
Field of the Invention
[0002] This invention relates to food processing and, more particularly, to, a
process for
pre-processing foodstuffs containing substances including starches, cellulose,
pectin,
and/or naturally occurring sugars and enzymes, such as potatoes, corn,
peppers, onions,
carrots, broccoli, squash and other vegetables; for subsequent further
processing and
consumption.
Background of the Invention
[0003] Commercially available pre-processed vegetables typically are prepared
by first
cutting (peeling and coring if required) whole vegetables into portions, such
as wedges,
slices, strips, shreds or rites then blanching those portions in hot water or
steam, followed
by cooling in air or water (emersion or deluge) and finally freezing. The
frozen vegetable
portions may then be re-thermed/reheated by the end user, typically a
restaurant, as an
ingredient or by means common to restaurant/commissary kitchens such as
boiling,
steaming, stir frying, grilling, roasting or sauteing, as by way of example.
Other re-
therming/reheating methods include oven heating and microwave heating. Most
prior
CA 02525716 2005-11-09
WO 2004/103131 PCT/US2004/016209
processes use variations of the foregoing pre-process, including additional
steps, to prepare
vegetable products for freezing and shipment to the consumer.
[0004] Commercially prepared potatoes typically are prepared by cutting whole
potatoes
into portions, such as wedges or strips, American "fries" or English "chips,"
blanching
those portions in hot water or steam, drying the strips in hot air, then par
frying the
portions in hot oil prior to freezing them. The frozen potato portions may
then be
reconstituted by the consumer, typically a restaurant, by frying them in oil
or heating them
in either a conventional or microwave type oven. Many prior processes use
variations of
the foregoing process, including some having additional process steps, to
prepare potato
products to be frozen for shipment to the consumer
[0005] In the alternative, fresh vegetables may be cleaned, cut and
refrigerated in their raw
state (without blanching) and then sold to similar businesses. This
abbreviated process
produces what is known as "fresh" product. Fresh product has the disadvantage
of having
a relatively short shelf life and reduced quality due to internal enzymatic
action within the
product, as well as degradation at the hands of spoiling agents.
[0006] In the case of vegetables, the vast majority of products are either
processed for
immediate use, short-term storage or long-term frozen storage. While
desirable, long-term
storage (>30 days) of processed, but unfrozen vegetable portions having
acceptable
organoleptic qualities has been difficult to achieve. Some of these prior
processes are
described below.
[0007] "Immediate use" vegetable products are harvested, cleaned of unusable
vegetable
matter and field debris, hand packaged and then cooled. Typically, this
process takes
place in or near the field where the vegetable products are harvested. These
products are
3
CA 02525716 2005-11-09
WO 2004/103131 PCT/US2004/016209
then typically transported directly to produce wholesalers, who then resell
them to local
retail, restaurant and commissary operations. Such fresh vegetables have a
relatively short
shelf life and, in many cases, still suffer significant degradation prior to
their reaching the
final customer. This means that the intended attributes of freshness are not
enjoyed by the
final customer. Evidence of this can be seen by the wilted and withered
appearance
typical of stale vegetables. While preferred for their flavor, fresh vegetable
products
require considerably longer preparation time than those that have been pre-
processed, thus
adding increased operating costs and health risks associated with cutting and
hot cooking
operations. Fresh vegetable products in this raw state require complete
preparation;
sanitation and full and complete cooking prior to being consumed safely by
end' users.
Since fresh vegetable,products do not cook quickly, the amount of time
required to prepare
them on-demand for consumption in a restaurant environment would certainly
over tax. the
patience of most patrons.
[0008] In contrast, short term stored products are similar to the above but
withstand the
vagaries of storage primarily due to their harvest prior to full maturity,
original product
quality or optimized storage facilities. Premium quality products are stored
oma longer
term basis in specifically designed high humidity, low oxygen, low temperature
environments that minimize enzymatic action caused by ambient temperature and
moisture
optimization via non-condensing near saturation conditions. While this
methodology of
storage allo'vs vegetable products to be stored .for longer periods of time,
it is very
expensive and is limited in its capacity. Unfortunately, vegetable product
quality still
degrades over time despite of following this storage method and corresponding
investment. '
4
CA 02525716 2005-11-09
WO 2004/103131 PCT/US2004/016209
[0009] The processing of vegetable products for long-term storage as taught by
traditional
methods begins by removing excess vegetable matter, field debris and other
unusables
from the product. Incoming raw product is then washed and, in some cases such,
as
potatoes, carrots, onions and sweet, potatoes (yams), peeled. Other products,
such as
peppers, are cored. Depending upon the final desired product, further
processing may
include slicing or sectioning. Generally slices range from thin, 1/32 inch
slices to thick
slices over two inches, whereas sectioned units can range from 2 to over 12
her vegetable
unit or even take the form of shreds or rices, for example. Sliced or
sectioned pieces then
are typically blanched in mediums that include a water bath, a water deluge,
heated
saturated air environment, microwave energy or live, high temperature steam:
Following
the blanching process, the product is cooled via water bath, water deluge or
chilled using
saturated air passing through a bed of the blanched product. Once the product
has cooled
down it is typically frozen by conventional means. Industrial systems pass
air, usually in
the range of -20 to -40 °F, through a bed of product to achieve
freezing of the product.
After freezing, the product is then packaged for storage. Generally, freezing
increases the
shelf life of the product rendering it more marketable and easier to ship and
store.
[00010] In the case of preparing of potato portioris~ the vast majority of
traditional
processes include at least one par frying step. During par frying, the potato
portions
typically are immersed in a tank of hot cooking oil or fat. Alternative
frying. methods may
be used such as "deluge" frying wherein hot frying oil is sprayed downwardly
or caused to
cascade downwardly onto the potato portions as they are conveyed beneath the
cooker.
The frying oil, which typically has a temperature of 350° F to
375° F, partially cooks the
potato portions, driving out moisture and thereby increasing the solids
percentage of those
CA 02525716 2005-11-09
WO 2004/103131 PCT/US2004/016209
portions. Removal of moisture from the potato portions is also~desirable in
order to reduce
hydrolysis of the cooking oil, thus prolonging its useful life. Unfortunately,
the par frying
step, while effective to quickly remove moisture content from potato portions,
is a
relatively harsh means for extracting moisture, especially at higher frying
temperatures,
thus adversely affecting the organoleptic qualities of the ultimate prepared
potato product.
[00011] While the traditional methods of fresh vegetable preparation,
packaging and
cooling allow for shipping with a modicum of short-term storability, they
neither stop
enzymatic activities nor optimize inter- and infra-cellular stabilization.
Failure to stop
enzymatic activities and optimize cell stability results in reduced shelf
life, degradation in
product appearance, such as discoloration and wilting, and increased efforts
by end users
expended in preparing the vegetables for the final customers. Additionally,
waste is
increased due to the aforementioned short shelf life due to unacceptable
depreciation iri the
vegetable's appearance, texture, turgor and flavor.
[00012] Processing of vegetable products into refrigerated or frozen states
traditionally
renders a product with characteristics that are not regarded as fresh.
Specifically, the
product color, texture, turgor and flavor are degraded enough to render the
products less
desirable than fresh products. Frozen products are also inferior to fresh
products because
freezing causes the breakdown of the vegetable's inter- and infra-cellular
conditions,
increased liquid purge and a loss of flavor characteristics.
[00013] With respect to potato product, while the traditional steps of high-
temperature
water (or steam) blanching, par frying and hot air drying facilitate moisture
removal and
other processing goals, they do not lend themselves to preparation of unfrozen
potato
portions and may contribute to several undesirable results. For one, over
blanching and
6
CA 02525716 2005-11-09
WO 2004/103131 PCT/US2004/016209
air-drying tends to cause dust-like potato particles to slough-off during
finish frying. As a
result, the frying oil tends to chemically break down and cloud up, smoke
prematurely,
turn rancid, and otherwise shortening the life of the frying oil. Second,
flavorings,
seasonings and spices tend to volatilize or vaporize in relatively high heat
and therefore
are "cooked out" of the final product. Third, high-temperature frying or use
of potatoes
having high sugar content can result in the portions becoming a darkened brown
color due
to the Maillard reaction which involves a reaction between reducing sugars and
amino
acids. To combat this effect, it has traditionally become necessary to start
with high-
quality potatoes having fewer reducing sugars. This need becomes even more
compelling
for frozen potato products designed to have a high solids content. Fourth,
some potato
flavor is lost as flavor components are degraded and/or volatilized in frying
oil heated to a
high temperature. This problem is even more acute with "low solids" potato
products
which require longer, more extensive processing. Lastly, fry time of frozen
vegetables,
such as potatoes, is longer than that for unfrozen.
[00014] Many of the foregoing consequences are exacerbated in conventional
processes
designed to allow vegetable products to be tored for short to long intervals.
Manufacturers seek to increase efficiency, reduce labor, and effectuate
reconstitution.
However, these are trade offs at the cost of degraded flavor, color and mouth
feel (texture -
and turgor). Properly processed, optimal quality product is only attainable
from vegetable
products that are premium in terms of quality attributes. Unfortunately, these
products are
very costly and of limited availability because of the logistics of getting
them from the
harvest field onto the customer's table. In addition, trying to preserve the
nature of the
fresh vegetables may dictate processing on a regional basis in order to
maintain short
7
CA 02525716 2005-11-09
WO 2004/103131 PCT/US2004/016209
shipping times and proper shipping environments. All of which makes the
products
expensive in spite of quality attributes that will still degrade markedly over
time.
[00015] The use of vacuum processes is well-known throughout the food
processing
industry. Specifically, vacuum infusion is used for the introduction of
flavors and property
enhancers for vegetable portions as well as some types of meat. This is done
by placing
the food portion in a chamber subjecting it to a vacuum and then introducing
various
flavorings and property enhancers that, due to the vacuum, penetrate into the
pores of the
treated portion when the vacuum is removed. Vacuum infusion may be employed to
treat
foodstuffs with various antibacterial and/or anti-fungicidal agents, as well.
[00016] Goldberg et al., in U.S. Patent No. 6,245,291, discusses the
application of biocidal
treatment to whole muscle meats, processed meats and various fruits as well as
porous and
nonporous foodstuffs. The focus of which is the destruction of bacteria and
spore formers
that are toxic to humans. Of particular interest is the use of vacuum to
induce movement
of the biocidal or non-biocidal substances. The focus of the disclosed process
is the
minimization of perceptible changes to the subject product by the end user.
This is in
contrast with the optimization of quality, attributes and storability that is
not dependant on
agents such as biocides.
[00017] A vacuum environment is specifically claimed in the embodiment by
Haamer, in
U.S.. Pat. Publ. No. US2003/0017238, where food or similar product to be
processed or
sterilized is packaged in a suitable flexible medium, such as plastic, and
then heated with
microwave or radio wave energy. The package is designed with a vented relief
valve that
allows for escape of gases during heating. At the termination of the heating
cycle, the vent
CA 02525716 2005-11-09
WO 2004/103131 PCT/US2004/016209
closes during cooling and a vacuum is formed. This vacuum packaging invention
is
focused specifically on long-term storage in a vacuum environment.
[00018] Some of the problems associated with traditional pre-processing of
potato portions
have been addressed in the art. Minelli et al., in U.S. Patent No. 6,514,554,
claims vacuum
application during par frying and blanching in an oil medium under a vacuum.
Neither of
these processes lends themselves to the preparation of potato and/or vegetable
portions
that can be packaged, shipped and prepared by the end user as a "fresh",
unfrozen,
vegetable product. Rather, Minelli focuses on in-vessel processing with water
or oil
mediums to attain the desired characteristics. It is well understood that this
is a very
expensive. process system in terms of both operational costs and investment
funding and
does not produce the most desirable vegetable characteristics.
[00019] With respect to potato portions that comprise the common American-
style potato
chip, these products generally: require the use of a more expensive raw potato
in order to
avoid dark brown product; are expensive to ship because of their bulk to
weight ratio; are
subject to breakage during transit; and can vary widely in freshness depending
upon how
long they are stored prior to use. These are undesirable product
characteristics that
manufacturers and operators would like to see eliminated.
[00020] The fresh produce industry uses vacuum cooling to cool cleaned or
freshly
harvested fruits and vegetables, including bean sprouts. See article
specifically entitled,
"Effects of Vacuum Cooling and Storage Temperature on the Quality of Bean
Sprouts,"
Jennifer R. DeEll et al., ENESAD, France. In such applications, the products
are
packaged, generally near the point of harvest. The packaging temperature is
lowered
utilizing various refrigeration techniques and vacuum systems. Product
temperature may
9
CA 02525716 2005-11-09
WO 2004/103131 PCT/US2004/016209
be near freezing at the completion of the process. This requires fresh
unprocessed product
that is packaged for distribution the goal being the removal of field heat in
preparation for
shipping.
[00021] In regard to the vacuum cooling of meat for catering systems,
Technical Paper No.
ICR065, M. Houska et al., describes methodology for subjecting various
processed meats
to a vacuum system for cooling. This disclosed system approaches only finished
ready-
for-distribution meat products. Additionally, infusion of ingredients into the
surface of the
meat under a vacuum is discussed, which is a common practice in the meat
industry.
[00022] Zhihang Zhang et al., in an experimental study on temperature and
weight loss
profiles of vacuum cooling of sliced cooked carrot Technical Paper No.
ICR0470,
discloses the use of vacuum systems in the cooling of cooked cut carrot
slices. In this
study it is verified that vacuum cooling is indeed an effective methodology
for cooling:
Testing was done on a very small lab scale with results being primarily
qualitative.
[00023] In the paper entitled "Free Volatile Components of Passion Fruit Puree
Obtained
by Flash Vacuum-Expansion", P. Brat et al., J. A~ric. Food CChem. 48 (12) the
authors
discuss essence extraction from passion fruit puree. This is quite similar to
common
multiple effect vacuum induced evaporators available in the art. Volatile
essence is
extracted from a host medium, generally process puree, then concentrated and
reclaimed
as a saleable product.
[00024] Accordingly, there remains a need .in the commercially processed
vegetable
product industry for a method of preparing whole vegetables and vegetable
portions that
offers one or more of the following advantages: a longer shelf life so
vegetables can be
shipped in a "fresh" condition, i.e., without a significant degradation in
color and/or loss of
CA 02525716 2005-11-09
WO 2004/103131 PCT/US2004/016209
texture and turgor; portions that can be prepared quickly~and on-demand by the
end user
with the appearance of being freshly prepared; pre-portioned vegetable
products that
exhibit resiliency, resist sticking together and that are less susceptible to
breakage prior to
final cooking or re-therming; retention of much of the vegetable's natural
flavors; and
reduced time and labor for final preparation. A combination of any one or more
of these
desirable attributes would yield a vegetable product that is, better tasting,
more cost
effective, more visually appealing, that could be cooked or displayed (i.e.,
salad bars) on
demand and be potentially more nutritious.
Summary of the Invention
[00025] In brief summary, the present invention comprises an improved pre-
process
method for preparing "fresh" vegetables, (including potatoes), vegetable and
potato .
portions and the like. As used herein "fresh" shall be used to identify
vegetables and
vegetable portions that have been processed according to the LintonizingTM
process in
contrast to the term "raw", which is the state of vegetables at the beginning
of the '
LintOnizingTM process. As used herein, the term "vegetable portions" may
include whole
vegetables as well. In addition to the present invention.being applied to
vegetables, it is
anticipated that the process can be used on some fruits as well and would
achieve'similar
results. LintonizingTM is a service mark for a proprietary process licensed to
Viands
Concerted, LLC of Columbus, Ohio.
[00026] In orie embodiment, peeled and portioned vegetable portions are
blanched, drained
of excess surface moisture, cooked at a low-temperature and low pressure and
then cooled
down prior to packaging. In another embodiment, the prepared and portioned
vegetables
11
CA 02525716 2005-11-09
WO 2004/103131 PCT/US2004/016209
are blanched, drained of excess surface moisture, then cooked at low
temperature and low
pressure and then treated with flavorings, flavor enhancers and/or
preservatives prior to
being packaged. In either embodiment, the vegetable portions may be rinsed
after cutting
and prior to blanching to remove pieces of any cutting residuals from the
vegetable
surface. To enhance the flavor and appearance of processed vegetables,
portions may be
grilled or roasted following the low temperature, low pressure cooking
process.
[00027] The foregoing process produces a high-quality vegetable product that
can be
shipped refrigerated, has a suitably long shelf life (typically >30 days),
produces flavorful,
attractive and organoleptically superior finished product, that is, a product
that exhibits
enhanced vegetable flavor, pleasing color and satisfying firmness. It also
provides the
food service industry with an exceptional, quick and easy access finished
portion that can
be re-thermed and/or reheated in a short period of time. Another advantage of
the present
invention is that it enables the enhancement of organoleptic qualities even
from lower
grade raw product, thus increasing quality while reducing costs. In some cases
fully
cooked vegetable portions prepared according to the present invention exhibit
the color
raw vegetables. As should be recognized by those skilled in the art, other
processing
advantages and improved product features will also be achieved by the present
invention.
Brief Description of the Drawing
[00028] Further features of the present invention will become apparent to
those skilled in
the art to which the present invention relates from reading the following
specification with
reference to the accompanying drawing, in which:
12
CA 02525716 2005-11-09
WO 2004/103131 PCT/US2004/016209
[00029] Figure 1 is a flow diagram of a process for inter- and infra-cellular
stabilization of
foodstuffs, and in particular vegetables (including potatoes), according to an
embodiment
of the present invention.
Detailed Description of a Preferred Embodiment
[00030] Referring to Fig. 1, in accordance with an embodiment of the present
invention,
raw vegetables, including without limitation, potatoes, 'corn, onions,
peppers, carrots,
squash, egg plant, sweet potatoes, and sugar snap peas, are delivered, stored
prior to
processing, unloaded, cleaned and inspected for defects, as shown in steps 10
thru 50.
Conventional cleaning methods for various products includes husking/de-silking
(corn),
peeling (root crops) and washing such as with a water plume, flume or spray.
The cleaned
vegetables may then be cut into portions or pieces suitably sized for the end
product as in
step 60. As used herein, the term "portions" is used in its broadest sense to
include strips
or segments, and vegetables cut to specific lengths, as well as substantially
whole
vegetables, in some cases. Immediately following cutting, the portions .may be
rinsed, as
at step 70, by spraying or immersing the vegetables in a water bath to remove
any process-
produced debris. .
[00031] The rinsed vegetable portions are then blanched at step 80 by
subjecting diem to
any number of means, including immersion in hot water, generally at about
165° F to
boiling from about 15 seconds up to 70 minutes, depending upon the
characteristics of the
vegetable being processed. Blanching may be accomplished by a number of
conventional
means, such as by immersion, steam, deluge or microwave. With the exception of
potatoes
and sweet potatoes (yams), a rolling boil water bath for 1 to 5 minutes is
utilized, for
13
CA 02525716 2005-11-09
WO 2004/103131 PCT/US2004/016209
around 90 seconds preferred. It will be appreciated that the water temperature
and
immersion time will vary (even outside the noted ranges) depending, among
other
variables, upon the cut configuration and size of the vegetable portions. In
the case of cob
corn, altitude consideration will also impact time in the boiling water
process. Generally,
the blanching step deactivates enzymes present in the vegetables and prevents
the
vegetables from discoloring during storage.
[00032] Alternatively, the vegetable portions may be blanched in steam, using
microwave
energy or in a deluge blancher at 80. The time and temperature combination for
the
blanching process is an important part of.the process. If the blanching time
is too short,
such as less than 15 seconds at 165° F, then the portion will be
insufficiently heated
resulting in enzymes that are not deactivated and leaving bacteria, yeasts and
molds that
are not adequately neutralized. On the other end of the timing spectrum, if
blanched too
long, such as 45 minutes or more at 185° F, then the portions will be
overcooked, become
t
mushy and too soft to handle. Likewise, blanching the portions at too high a
temperature,
such as 195°, F or greater, for as long as 70 minutes or more, will
cause~most vegetable ,
portions to become mushy, discolored and undesirable to the final consumer.
[00033] ~ Following the blanching process, the portions are. quickly drained
of excess surface
moisture as at step 80 before further processing. A shaking process or a high
velocity fan
air knife may be used to rapidly blow off excess surface moisture while trying
to retain as
much heat in the portions as possible. Such equipment can also be included in
the
blanching process.
[00034] ' Steps 10 through, and including, step 80 are well known processes
within the
vegetable processing industry and are shown in Fig. 1 called out with arrows
and entitled
14
CA 02525716 2005-11-09
WO 2004/103131 PCT/US2004/016209
"Traditional Processing Methods". Those skilled in. the art will quickly
recognize these as
such. Standard industrial and commercial equipment systems are readily
utilized in the
processes and will not be discussed in detail here.
[00035], ' , The process, according to the present invention, includes
transfer of drained
vegetable portions to a sealed vacuum chamber in which they are subjected to a
vacuum
while they are still in a heated state from the prior blanching process, as
shown in step 90.
The vacuum vessel access door is designed to close and lock. Once the vessel
is loaded
and locked, a valve opens, allowing the vacuum pressure contained in the
system's
accumulator to rapidly bring the vessel to a predetermined level of vacuity.
If required, a
vacuum pump can operate in an automatic mode to further aid in achieving the
target
vacuity in a short period of time, with about 30 seconds being preferred.
While the target
vacuum ramp time may vary to cut down on the processing time, it is desirable
for the
target vacuum to be attained as quickly as possible. The applied vacuum is
permitted to
ramp up from ambient atmospheric pressure to around 15" Hg to 30" Hg where it
is
maintained in the range of about 15" Hg to 30" Hg, preferably about 27.5" Hg,
for a
period that can range up to 70 minutes. Depending upon the vacuum source and
methodology used, it may take as much as 10 minutes or more to reach the
desired level of
vacuity. During the vacuum cycle, moisture is extracted.from the surface and .
.
microstructure of the vegetable portions, part of which immediately vaporizes.
The .
remainder is surface borne liquid and is removed later in the process, as
evidenced by
accumulation of water in the accumulator and water vapor discharge from the
system
vacuum pump. As further evidenced by pauses in vacuity rate at approximately 1
~" Hg
and 21" Hg, it is believed that the heat of vaporization point is achieved
around these two
CA 02525716 2005-11-09
WO 2004/103131 PCT/US2004/016209
vacuum levels. In contrast, cob corn does not exhibit this phenomenon, wherein
the
vacuity rate is constant over the entire curve until target vacuum is
achieved.
[00036] Decompression of the vessel to atmospheric pressure employed at step
90 occurs
quickly by the actuation of a relief valve. In one embodiment of the
invention, the vacuum
vessel at step 90 may additionally comprise a cooling means where the exterior
of the
vessel is deluge cooled during or following the vacuum cycle. It is believed
that the
introduction of additional cooling media will further aid the cooling and
stabilization of
vegetable portions. However, testing has shown that when liquid nitrogen is -
induced into
the vessel at step 90 at the termination of the vacuum cycle, the drastic
cooling rate,
provided by the liquid nitrogen produced a deleterious effect on, not only the
surface. of
the vegetable portion, but also in the micro fibril cellulose structure of the
processed
vegetable portions.
[00037] One desirable benefit of the invention, is that the micro fibril
cellulose structure of
the vegetable portions is purged of excess water during the low temperature,
low pressure
cooking process. This results in the toughening of the cell walls and
cellulose fibers. This
optimizes texture and turgor in the vegetable portions particularly desirable
for extended
refrigerated storage. It will be appreciated that the actual vacuum parameters
are
influenced by'a number of factors including the physical characteristics of
the product
portion being processed and target specifications of the final product.
[00038] Following the vacuum cycle at step 90, the fresh vegetable portions
may be passed
through a machine that adds grill or roasting marks, as at 102, to the surface
of the
vegetable portions. This may be accomplished prior to cooling at 100,
including
immersion in a water bath, air or mist, having ozone or chlorine dioxide or
other bacterial,
16
CA 02525716 2005-11-09
WO 2004/103131 PCT/US2004/016209
mold and yeast treating agents. These agents may be supplied via a pump at
step 101. In
an alternate embodiment the vegetable portions are sprayed with the sanitizing
agent just
prior to a dewatering process as illustrated at step 110. Pump 101 supplies
the sanitizer
agent to either process 100 or 110. The vegetable portions are then
transferred to a
dewatering device 110 where surface water is removed via high velocity air
provided by
an air stripper or other suitable dewatering device.
[00039] Vegetable portions may then packaged at step 120 where excess air may
be
evacuated the package via a vacuum pump following the introduction of inert
gases such
as C02, N2 and/or other inert gases appropriate to the particular vegetable
portions..
Packaged products may then be transported to a warehouse for storage 130 or
shipped
directly to the consumer, as shown at step 140.
[00040] As can be appreciated by those skilled in the art, flavor and texture
components of
vegetable portions may be significantly degraded during each process phase of
the
traditional process. This is due primarily to the evaporation of essences and
other
components in the vegetable that are volatile and the adverse effect on the
micro fibril
cellulose structure and cellulose treatment. The present low temperature, low
pressure
cooking process preserves these delicate flavors, color, and texture
components for several
different product applications because it maximizes water removal within.cell
structure
and strengthens cellular and cellulose fibers even at very low temperatures.
[00041] In summary, many advantages are achieved by the present process
because the
vegetable portions are subjected to processing steps that enhance stored
product
characteristics through the storage period, aid in simpler safer preparation
and are pleasing
to the consumer's eye and palate.
17
CA 02525716 2005-11-09
WO 2004/103131 PCT/US2004/016209
EXAMPLES
[00042] Example 1. This first example illustrates one application of the
present invention.
The general parameters in this example apply to a cob corn configuration.
[00043] Whole cob corn, recently harvested (within 1 to 4 weeks) were
received,
husked/de-Bilked, inspected, cut to predetermined lengths and then rinsed to
remove
surface starch, sugars and residual debiis from cutting. The portions were
then immersion
blanched in boiling water (rolling boil) for about 90 seconds and reaching a
core
temperature of around 125° F. The portions were removed from the blanch
water, shaken
to remove excess surface moisture and then directly placed into a vacuum
vessel as at 90.
[00044] The portions were then subjected to a rapid vacuum, ramping up to
27.5" Hg over a
22 second period, continuing to cook as the portions cooled down to around
110° F.
Following the vacuum process, the cob corn portions were transferred to a
water bath
enriched with ozonated water and allowed to remain submerged for 3 minutes for
the
destruction of any mold spores, bacteria or other organic contaminates. The
product was
then packaged, where specifically designed gas packaging in a flexible medium
was
completed.
[00045] Following around 21 days of storage, the portions prepared in
accordance with the
process of the present invention were then removed from the packaging and
prepared by
boiling in water and by microwave heating. The resulting portions were very
tender, juicy.
and tasted sweet with excellent color and minimal wrinlding or puckering of
corn kernels,
as is typically encountered when reheating cob corn prepared in a traditional
manner.
1~
CA 02525716 2005-11-09
WO 2004/103131 PCT/US2004/016209
[00046] Example 2. This second example illustrates another application of the
present
invention. The general parameters in this example apply to a medley of
vegetable
portions.
[00047] A medley of recently harvested whole peppers, onions and zucchini
squash were
received, cleaned, cored (peppers), peeled (onions), inspected, cut into
predetermined
portions and then rinsed to remove surface residual debris from coring,
peeling and
cutting. The medley of vegetable portions was then immersion blanched in
boiling
(rolling boil) for about 90 seconds until interior product temperature reached
around 154°
F. The portions were removed from the blanch water, shaken to remove excess
surface
moisture and then directly placed into a vacuum vessel at step 90.
[00048] The portions were then subjected to a vacuum ramping up to around
27.5" Hg for
23 seconds, where they continued to cook as they cooled down to around
106° F.
Following the 23 second vacuum process, the vacuum was released and the
portions were
transferred to a water bath enriched with ozone and allowed to remain
submerged for 3
minutes for treatment of any mold spores, bacteria or related organic
contaminates. The
medley of vegetable product was then transferred to a flexible, gas-filled
packaging
medium.
[00049] ~ Following a storage period of around 21 days, the portions subjected
to the ,
LintonizingTM process were then removed from their package and reheated, then
observed
and sampled. The portions were tender, but slightly crunchy, juicy and
flavorful with
bright color and pleasing appearance. These products were ready for immediate
consumption, furthering grilling or as a meal side dish, right out of the
package.
19
CA 02525716 2005-11-09
WO 2004/103131 PCT/US2004/016209
[00050] Exam 1p a 3. This third example illustrates another application of the
present
invention. The general parameters in this example apply to sliced sweet potato
(yam)
portions.
[00051] Recently harvested whole sweet potatoes were received, peeled,
cleaned, inspected,
cut in predetermined slices of about 1/6" in thickness and then rinsed to
remove any
remaining surface residual debris. The portions were then immersion blanched
in 185° F
hot water for about 10 minutes. The yam portions were removed from the blanch
water,
shaken to remove excess surface moisture and then directly placed into a
vacuum vessel
90.
[00052] The yam portions then were subjected to a vacuum ramping up to around
27" Hg
and held for 10 minutes. Following the vacuum process the yam portions were
submerged
in ozone enriched water for 3 minutes, then removed, and excess water shaken
off. The
portions were then transferred to a deep fat fryer where they were fried for
approximately
3 minutes at 350° F.
[00053] The yam portions subjected to the LintonizingTM process were then
removed and
compared to unprocessed yam portions that had previously been deep-fried. The
portions
processed according to the present invention exhibited a significant
improvement in
appearance, texture and mouth feel as compared to the unprocessed portions,
which were
very dark in color, mottled and had a heavy burnt sugar taste.
[00054] Example 4. This fourth example illustrates another application of the
present
invention. The general parameters in this example apply to onion portions
specifically .
sectioned into 4 quarter sections.
CA 02525716 2005-11-09
WO 2004/103131 PCT/US2004/016209
[00055] Recently harvested whole onions were received, peeled, cleaned,
inspected, cut to
'/a sections and then rinsed to remove surface residual debris from cutting.
Following the
blanching, the onion portions were then immersion blanched in boiling water
for 30
seconds. The portions were removed from the blanch water, shaken to remove
excess
surface moisture and then directly placed into vacuum vessel 90.
[00056] The onion portions then were subjected to a vacuum ramping up to
around 27" Hg
and held for 10 minutes. Following the vacuum process, the onion portions were
transferred to an open-flame grilling apparatus and then grilled to a pleasing
appearance.
For comparison purposes, unprocessed onion sections were grilled as well.
[00057] The batches of onion portions were then physically compared and taste
tested. The
processed onion portions exhibited markedly better flavor appearance (bright),
texture and
mouth feel, particularly in crispness as compared to the grilled, but
unprocessed; onion
portions.
[00058] Example 5. This fifth example illustrates yet another application of
the present
invention. The general parameters in this example apply to vegetable portions,
specifically sugar snap peas.
[00059] Recently harvested sugar snap peas were received, cleaned and
inspected. The pea
portions were then immersion blanched in boiling water for 30 seconds. The pea
portions
were removed from the blanch water, shaken to remove excess surface moisture
and then
directly placed into a vacuum vessel 90.
[00060] The pea portions then were subjected to a vacuum ramping up to about
27" Hg and
held for about 10 minutes. Following the hold time, the vacuum was removed and
the
21
CA 02525716 2005-11-09
WO 2004/103131 PCT/US2004/016209
processed portions were transferred to a viewing area for side-by-side
comparison to pea
portions that had undergone only blanching.
[00061] The pea portions processed according to the present invention
exhibited marked
improvements in appearance (bright and colorful), texture and mouth feel,
especially
crispness, in side-by-side comparison with pea portions processed in the
traditional
fashion.
[00062] Example 6. This sixth example illustrates another application of the
present
invention. The general parameters in this example apply to potato portions.
[00063] Raw potatoes of the Russet variety were cleaned and then cut into thin
slices,
appropriately sized for American potato chips. Following their being slices,
the portions
were rinsed in a cold water bath to remove any debris. The rinsed potato
portions where
then blanched by immersion into hot water at around 175° F to
180° F for a period of about
minutes. Following the blanching process, the potato slices are quickly
drained and
then transferred to a pressure vessel wherein they are subject to a vacuum
ramping up from
ambient to around 27.5" Hg. Once the desired vacuity is achieved, the vacuum
is
removed, bringing the potato portions back to atmospheric pressure. Following
the
vacuum cooking step, the potato slices were examined and were shown to exhibit
a
number of desirable characteristics. First, the slices were resilient and were
easily handled
without breakage. Secondly, the LintonizedTM potato slices exhibited much less
stickiness .
as compared to those processed by traditional means. Further, from a taste
standpoint, the
processed slices exhibited a pleasing, elevated cooked potato flavor. The
potato slices
were then transferred to a plastic pouch, evacuated of air and then sealed
using an inert gas
mixture of nitrogen and caxbon dioxide, then refrigerated.
22
CA 02525716 2005-11-09
WO 2004/103131 PCT/US2004/016209
[00064] After 21 days the potato slices were removed from their plastic
packages and
further prepared by deep frying them in hot, relatively inexpensive vegetable
oil at 350° F
for about 90-120 seconds. The resulting chip portions were very crisp and had
a
consistent, light golden color among the multiple chip portions. The portions
appeared to
absorb very little oil and had a light, delicate and crisp texture with a
noticeably pleasant,
fresh potato flavor. The fried portions remained crisp even after four days in
an ambient,
low humidity atmosphere.
[00065] Having illustrated and described the principles of the invention with
reference to
several preferred embodiments, it should be apparent to those of ordinary
skill in the art
that the invention may be modified in arrangement and detail without departing
from such
principles.
[00066] While the present invention may be used to prepare refrigerated/frozen
vegetable
products for later re-therming by common restaurant or commissary means, it
also m,ay be
used to produce products intended to be re-thermed by other methods such as
oven
heating, roasting, frying, steaming, boiling, grilling, etc.
23
