U.S. patent application number 10/488329 was filed with the patent office on 2005-05-05 for process and equipment.
Invention is credited to Barwick, Bryan Edwin, Kelly, Thomas Reid, Sawant, Vilaj Arjun.
Application Number | 20050095337 10/488329 |
Document ID | / |
Family ID | 9921238 |
Filed Date | 2005-05-05 |
United States Patent
Application |
20050095337 |
Kind Code |
A1 |
Kelly, Thomas Reid ; et
al. |
May 5, 2005 |
Process and equipment
Abstract
Problems with incipiently gelling alginate or low-methoxy
pectate sols in a bath of an aqueous solution containing calcium
ions are reduced by having in the bath a perforated support surface
which can be oscillated. The surface is preferably oscillated
horizontally and vertically and preferably these oscillations are
synchronised. Transport means to remove the product from the bath
can be provided at one end of the bath. It is advantageous to
ensure that at the beginning of the vertical oscillation the
horizontal oscillation is in the direction of such transport means.
Portions of the sol can be formed by extrusion either below or
above the surface of the bath. The process is particularly useful
for sols which have a sugar content greater than 10%. The invention
also provides equipment comprising such a perforated support
surface. Although the equipment is particularly useful for
preparing alginate and low-methoxy pectate products it can also be
used advantageously for other products which are formed in a bath
and are susceptible to damage before they solidify adequately.
Inventors: |
Kelly, Thomas Reid;
(Northants, GB) ; Barwick, Bryan Edwin;
(Northants, GB) ; Sawant, Vilaj Arjun; (Northants,
GB) |
Correspondence
Address: |
Frank J Uxa
Stout Uxa Buyan & Mullins
Suite 300
4 Venture
Irvine
CA
92618
US
|
Family ID: |
9921238 |
Appl. No.: |
10/488329 |
Filed: |
December 10, 2004 |
PCT Filed: |
August 27, 2002 |
PCT NO: |
PCT/GB02/03945 |
Current U.S.
Class: |
426/573 |
Current CPC
Class: |
A23L 21/18 20160801;
A23L 29/256 20160801; A23L 29/231 20160801 |
Class at
Publication: |
426/573 |
International
Class: |
A23L 001/05 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 30, 2001 |
GB |
0121037.6 |
Claims
1. A process comprising: treating portions of an aqueous alginate
sol or an aqueous low-methoxy pectate sol with an aqueous solution
containing dissolved calcium ions in a bath so that the calcium
ions diffuse into the sol thereby gelling the sol to form portions
of alginate or low-methoxy pectate gel in which the aqueous
solution containing dissolved calcium ions has a lower density than
the density of the sol wherein the bath contains an oscillated
perforated support surface effective to catch descending
incipiently-gelling portions of the aqueous alginate sol or the
aqueous low-methoxy pectate sol.
2. A process according to claim 1 in which the aqueous alginate sol
or aqueous low-methoxy pectate sol has a density at least 0.002
g/ml greater than the density of the aqueous solution containing
dissolved calcium ions.
3. A process according to claim 2 in which the density of the
aqueous alginate sol or the aqueous low-methoxy pectate sol is at
least 1.3 g/ml.
4. A process according to claim 1 in which the support surface is
oscillated vertically.
5. A process according to claim 4 in which the support surface is
also oscillated horizontally.
6. A process according to claim 5 in which the vertical and
horizontal oscillations of the support surface are
synchronised.
7. A process according to claim 6 in which the incipiently gelling
portions of the aqueous alginate sol or the aqueous low-methoxy
pectate are removed from the bath by transport means provided at
one end of the support surface.
8. A process according to claim 7 in which when each vertical
oscillation begins horizontal oscillation is in the direction of
the transport means.
9. A process according to claim 8 in which the end of the support
surface furthest from the transport means oscillates vertically
over a shorter distance than the end of the support surface nearest
the transport means.
10. A process according to claim 9 in which the vertical
oscillation of the support surface is synchronized so that the end
of the support surface nearest the transport means reaches its
lowest point just after the end of the support surface furthest
from the transport means reaches its lowest point.
11. A process according to claim 10 in which the vertical
oscillation of the support surface is synchronised so that the
support surface is horizontal when lowest.
12. A process according to claim 1 in which the support surface is
never less than 5 cms below the surface in the bath of the aqueous
solution containing dissolved calcium ions.
13. A process according to claim 12 in which the support surface is
not more than 30 cms below the surface in the bath of the aqueous
solution containing dissolved calcium ions.
14. A process according to claim 13 in which the support surface is
not more than 20 cms below the surface in the bath of the aqueous
solution containing dissolved calcium ions.
15. A process according to claim 1 in which the portions of the
aqueous alginate sol or aqueous low-methoxy pectate sol are formed
by extrusion through a nozzle below the surface in the bath of the
aqueous solution containing dissolved calcium ions.
16. A process according to claim 15 in which the nozzle is not more
than 5 cms below the surface in the bath of the aqueous solution
containing dissolved calcium ions.
17. A process according to claim 1 in which the calcium ions are
provided from calcium lactate.
18. A process according to claim 1 in which the aqueous alginate
sol or the low-methoxy pectate sol contains dispersed fruit
puree.
19. A process according to claim 18 in which in the aqueous
alginate sol or the low-methoxy pectate sol there is more than 10%
of sugar.
20. A process according to claim 19 in which in the sugar fructose
predominates.
21. A process according to claim 20 in which fructose is the only
added sugar.
22. A process according to claim in which the sol is an aqueous
alginate sol.
23. A process according to claim 1 further comprising storing the
incipiently-gelling portions of the aqueous alginate sol or the
aqueous low-methoxy pectate sol after the portions have been
removed from the bath in a support matrix having a balanced density
to ensure the incipiently-gelling portions are not deformed while
firming up by diffusion of calcium into the portions.
24. A continuous process according to claim 1.
25. A gelled product based on an alginate gel or low-methoxy
pectate gel formed according to claim 1.
26. A system suitable for use in preparing products which are
formed in a bath and are susceptible to damage before the products
solidify adequately, comprising a bath, a perforated support
surface in the bath for the products and an oscillating assembly
adapted and structured to oscillate the support surface.
27. The system according to claim 26 further comprising an
extrusion nozzle positioned to deliver the products to the
bath.
28. The system according to claim 26 in which the oscillating
assembly is structured to be able to oscillate the support surface
at least vertically.
29. The system according to claim 28 in which the oscillating
assembly is structured to be able to oscillate the support surface
vertically and horizontally.
30. The system according to claim 29 further comprising a transport
assembly provided at one end of the support surface and structured
to remove the products from the bath.
31. The system according to claim 30 in which the oscillating
assembly is structured such that when each vertical oscillation
begins horizontal oscillation is towards the transport
assembly.
32. The system according to claim 31 in which the oscillating
assembly is structured such that the end of the support surface
furthest from the transport assembly oscillates vertically over a
shorter distance than the end of the support surface nearest the
transport assembly.
33. The system according to claim 32 in which the oscillating
assembly is structured such that vertical oscillation of the
support surface is synchronized so that the end of the support
surface nearest the transport assembly reaches its lowest point
just after the end of the support surface furthest from the
transport assembly reaches its lowest point.
34. The system according to claim 30 in which the oscillating
assembly is structured such that the support surface is horizontal
when lowest.
35. The system according to claim 27 in which the bath includes an
input for a solution containing dissolved calcium ions and an
outlet for the solution determining the level of the solution when
the solution is in the bath.
36. The system according to claim 35 in which the oscillating
assembly is structured such that the support surface is never less
than 5 cms below the level of the solution when the solution is in
the bath.
37. The system according to claim 35 in which the oscillating
assembly is structured such that the support surface is never more
than 30 cms below the level of the solution when the solution is in
the bath.
38. The system according to claim 37 in which the oscillating
assembly is structured such that the support surface is never more
than 20 cms below the level of the solution when the solution is in
the bath.
39. The system according to claim 35 in which the extrusion nozzle
is below the level of the solution when the solution is in the
bath.
40. The system according to claim 39 in which the extrusion nozzle
is not more than 5 cms below the level of the solution when the
solution is in the bath.
41. The system according to claim 40 in which the oscillating
assembly is structured such that the support surface is never less
than 5 cms below the extrusion nozzle.
42. (canceled)
43. (canceled)
Description
[0001] Processes for preparing simulated fruit have been described.
An aqueous alginate or low-methoxy pectate sol incorporating
dispersed fruit puree is treated with an aqueous solution
containing dissolved calcium ions to allow the calcium ions to
diffuse into the sol thereby gelling it. For instance, to prepare
small simulated fruits, e.g. cherries or berry fruits, spherical
portions of the sol containing dispersed fruit puree are contacted
with the aqueous solution containing calcium ions. Such processes
can also be used to prepare similar products not based on
fruit.
[0002] In such methods of preparing alginate or low-methoxy pectate
based products it is important to ensure that the products do not
become distorted. This is normally achieved by adjusting the
density of the aqueous solution containing calcium ions to ensure
that the portions of alginate or low-methoxy pectate sol just float
in the bath. This avoids distortion of the products by contact with
the base of the bath or even from contact with the surface of the
bath. But we have found that for high density products, e.g. high
sugar products, adjusting the density of the bath containing
calcium ions so that the portions of alginate or low-methoxy
pectate sol just float leads to unacceptably slow gelation of the
sol.
[0003] We have found that improved gelation can be achieved by
using a perforated and oscillated support surface in the bath and
with relatively low density aqueous solutions containing calcium
ions. Our invention therefore provides a process in which portions
of alginate or low-methoxy pectate sol are treated with an aqueous
solution containing dissolved calcium ions in a bath so that the
calcium ions diffuse into the sol thereby gelling it to form
portions of alginate or low-methoxy pectate gel in which the
aqueous solution containing dissolved calcium ions has a lower
density than the density of the sol and the bath contains a
perforated support surface plate to catch the descending
incipiently-gelling portions of alginate or low-methoxy pectate sol
which perforated support surface is oscillated.
[0004] Using our process the time for adequate surface setting of
the portions of sol can be reduced from hours to a few minutes.
Also our process enables achievement of tightly controlled
residence times of the portions of alginate or low-methoxy pectate
sol in the aqueous solution containing calcium ions.
[0005] Our process is particularly useful for preparing fruit-based
products. For instance such products can advantageously contain
high concentrations of sugar i.e. have high densities.
[0006] Our invention lies also in providing equipment suitable for
use in the preparation of gelled alginate or low-methoxy pectate
products which equipment comprises a bath which bath contains a
perforated support surface for the products and oscillating means
to oscillate the support surface. The equipment can also comprise
an extrusion nozzle to deliver the product to the bath. Although
the equipment is particularly useful for preparing alginate and
low-methoxy pectate products it can also be used advantageously for
other products which are formed in a bath and are susceptible to
damage before they solidify adequately.
[0007] An especially preferred aspect of our invention is the use
of a perforated and oscillated support surface when the alginate or
low-methoxy pectate sol has a density at least 0.002 g/ml greater
than that of the aqueous solution containing dissolved calcium
ions. The process is particularly important for sols which have a
density of at least 1.3 g/ml. For such sols it remains optimal for
the density of the aqueous solution not to be greater than e.g. the
density of a saturated aqueous solution of calcium lactate. It is
unlikely that sols will be used which have densities higher than
1.5 g/ml but if they were, then there would still be no significant
benefit in increasing the density of the aqueous solution
containing dissolved calcium ions. References to densities are to
densities at the relevant temperature in the process.
[0008] The support surface can be oscillated vertically or
horizontally. Vertical oscillation is particularly significant and
can work alone e.g. if the aqueous solution containing dissolved
calcium ions flows over the support surface towards the transport
means. But particularly preferably the support surface is
oscillated both horizontally and vertically.
[0009] In a preferred form of the invention transport means are
provided to remove product from the bath, preferably catching the
products as they come off the support surface. The transport means
are preferably at one end of the support surface.
[0010] In a particularly preferred form of the invention the
vertical and horizontal oscillations of the support surface are
synchronised. With such synchronised oscillation it is especially
advantageous to ensure that, at the beginning of the upward
movement of the vertical oscillation, the horizontal oscillation is
in the direction of the transport means. The synchronised vertical
and horizontal oscillations cause the support surface to move at an
angle to the vertical. It is reasonably easy to achieve appropriate
throughputs of the products by adjusting the angle and the
frequency and length of the oscillations. In a specially preferred
form of the invention the rear end of the support surface
oscillates vertically over a shorter distance than the front end of
the support surface. ("Rear" and "front" are in relation to the
position of the transport means.) The movement of the front and
rear ends of the support surface are preferably such that the front
end reaches its lowest point just after the rear end reaches its
lowest point. The support surface is preferably horizontal at its
lowest point. It should be noted that a sloped but not oscillated
support surface is ineffective.
[0011] The dimensions of the perforations in the support surface of
course have to be such as to prevent the product falling through.
The perforations are preferably such as to fluidise the incipiently
gelling portions of alginate or low-methoxy pectate sol
particularly when the support surface is oscillated vertically.
Conveniently the perforations are circular.
[0012] We have also found that the perforated and oscillated
support surface is preferably never less than 5 cms below the
surface of the bath during the process i.e. even at its highest
point when oscillated vertically. It should be noted that a very
significant advantage of our invention is that our oscillated and
perforated support surface can be as close to the surface of the
bath as this or even closer. This is despite the products only
being incipiently gelling. A normal surface would have to be more
than 40 cms below the surface of the bath. In our process there is
little point in having the support surface more than 30 cms below
the surface of the bath as the greater the distance below the
surface of the bath the larger the bath has to be with consequent
larger quantities of bath liquor etc.
[0013] To minimise disadvantages of too long immersion, e.g. loss
of solids from the product into the bath liquor and diffusion of
water into the products, we prefer to have the support surface not
more than 20 cms below the surface of the bath. Raising the bath
temperature to above 30.degree. C. e.g. 45.degree. C. helps.
[0014] The portions of alginate or low-methoxy pectate sol are
preferably formed by extrusion through a nozzle below the surface
of the aqueous solution containing dissolved calcium ions. This is
particularly so for products simulating larger fruits such as
cherries. But the portions of alginate or low-methoxy pectate sol
can be formed above the surface of the aqueous solution. With
products the size of smaller fruits such as blackcurrants drops of
the right size can be formed easily and dropped into the aqueous
solution containing calcium ions. When the extrusion nozzle is
below the surface of the aqueous solution it is advantageous for it
to be not more than 5 cms below the surface of the bath. The
support surface should be at least 5 cms below the extrusion
nozzle.
[0015] Calcium lactate is our preferred source of calcium ions,
particularly for food products, but other soluble calcium salts can
be used e.g. calcium chloride, calcium acetate monohydrate,
monocalcium phosphate monohydrate, monocalcium phosphate anhydrous
and calcium gluconate.
[0016] Our process is especially useful in the preparation of
simulated fruit. For this purpose the alginate or low-methoxy
pectate sol can conveniently contain dispersed fruit puree. Our
process is particularly advantageous when the sol has a relatively
high sugar content. The sugar content is advantageously at least
10% and particularly preferably above 50%. A normal practical upper
limit is 85%. We have also found that it is advantageous for
fructose to be the predominant sugar i.e. forms more than 50% of
the total sugars present. Preferably pure fructose is the only
added sugar but, although not as preferred, the fructose can be in
mixture with other sugars e.g. as in fructose syrups.
[0017] The products are preferably stored in a support matrix which
has a balanced density to ensure the product is not deformed whilst
it is firming up by diffusion of calcium ions into the core of the
product.
[0018] Although our process can advantageously be used in the
preparation of simulated fruit, it can be used to produce other
products, especially but not only, other food products. For other
products, vegetable puree or minced or pureed meat, for instance,
can be used instead of fruit material.
[0019] Aqueous alginate sol is the preferred sol. When low-methoxy
pectate is used it should preferably contain less than 30%
methoxylated hydroxyl groups. "Low methoxy pectate" is a well-known
term. The normal dividing line between low-methoxy pectate (or
pectin) and high-methoxy pectate (or pectin) is 50% methoxylated
hydroxyl groups. The alginate or low-methoxy pectate sol will
usually be in the form of its sodium salt but potassium or ammonium
salts can be used.
[0020] Our process can be used to produce products of a wide range
of sizes and shapes. But conveniently the products are "spherical".
They can have diameters for instance as low as 5 mm and as high as
30 mm. 25 mm is a preferred maximum diameter and 8 mm is a
preferred minimum. The diameter of the nozzle and the time in the
bath have to be altered appropriately for larger or smaller
products. For instance 1 minute is ample for products, like
simulated blueberries, with a diameter of 7 mm and 12 minutes can
be necessary for products, like cherries, with a diameter of 25 mm.
(Note that in comparison with earlier processes our process can
achieve shorter residence times and very consistent residence
times. It is particularly suited for continuous operation.)
[0021] Spherical portions of alginate and low-methoxy pectate sol
can conveniently be formed by extruding the sol below the surface
of the aqueous solution containing dissolved calcium ions through a
nozzle of an appropriate diameter and separating the extruded sol
to form approximately cylindrical portions with a length:diameter
ratio of approximately 1:1. It is relatively simple to determine
appropriate extrusion rates and cutting rates for a given size of
nozzle.
[0022] In the extreme products of our process, and the portions of
sol used in their preparation, can be perfectly spherical but they
can vary from perfect spheres as do for instance spherical-shaped
natural fruits. Indeed for instance deliberately elongated spheres
e.g. grape-shaped products can be produced.
[0023] Suitable equipment constructed in accordance with the
invention and a suitable process in accordance with the invention
will now be described in greater detail, by way of example only,
with reference to the accompanying Figures.
[0024] FIG. 1 is a flow-chart of the process and equipment prior to
extrusion.
[0025] FIG. 2 is a flow-chart of the process and equipment from
extrusion to packaging of the product.
[0026] FIG. 3 is a cross-section showing the extrusion head, the
bath, the support surface and the transport mechanism.
[0027] Referring to FIG. 1:
[0028] Sodium alginate (Manugel DMB trade mark of ISP Alginates and
obtainable from ISP (Alginates) UK) was slurried in glycerol by
adding the alginate to the glycerol whilst gently stirring. The
slurry was metered from tank T1 by pump P1 to a mixer M1.
High-fructose syrup was metered from tank T2 by pump P2 also to
mixer M1 which dispersed the alginate in the syrup. The
syrup/alginate (see formulation) was passed down a coil C1 to a
tank T4 where it was stored for at least 4 hours, typically
overnight to allow complete hydration of the alginate. To ensure a
supply of fully hydrated alginate sol it is sensible to have two
tanks i.e. tanks T3 and T4 used alternately.
[0029] The syrup/alginate, an aqueous alginate sol with a high
fructose content, produced the previous day and held in tank T4,
was then pumped by pump P3 via a hopper H1 with an auger to mixer
M2 (a dynamic in-line mixer e.g. a Mini Mondomixer available from
Mondomix of the Netherlands).
[0030] A cherry mix was prepared from cherry puree and fructose
with other minor ingredients (see formulation) and stored in tanks
T5 and T6. The cherry mix was metered by pump P4 via a hopper H2
with an auger to mixer M2 to produce an aqueous alginate sol
containing dispersed cherry pulp and with a high sugar content and
to feed this to an extrusion head shown in FIG. 2.
[0031] Referring to FIG. 2:
[0032] The aqueous alginate sol containing dispersed cherry pulp
with a high fructose content prepared as described above with
reference to FIG. 1 was fed to an extrusion head E1. Tank T5
contained a bath of an aqueous solution of 5% calcium lactate into
which the aqueous alginate sol containing dispersed cherry pulp
with a high sugar content was extruded. Cherry-sized products were
formed as described below in connection with FIG. 3.
[0033] Transporter TR1 transported the products out of the solution
of calcium lactate to final containers e.g. containers H3. Before
they reached container H3 excess lactate was blown off them.
Container H3 contained a support matrix with a balanced density to
ensure the product is not deformed whilst it is firming up by
diffusion of calcium ions into the core of the product. The support
matrix was pumped by pump P6 from hopper H4. The ratio of support
matrix to product was about 1:4 when the container is adequately
full.
[0034] The solution of calcium lactate was pumped by pump P5 from a
make-up tank T6, then through a heat-exchanger to return to tank T5
from which it flowed over a weir to tank T6. A muslin bag kept
replenished with calcium lactate was suspended in tank T6 to
maintain the concentration of the calcium lactate. The density of
the solution of calcium lactate was approximately 1.04 g/ml. The
solution of calcium lactate was heated in heat exchanger (HE1) to
maintain a temperature of 45.degree. C. in tank T5. An advantage of
our process is that there is little or no waste material to be
removed from the system, after establishment of a balanced process,
and it can be used continuously.
[0035] Referring to FIG. 3:
[0036] Extrusion head E1 and the pneumatic piston PP1 are shown as
are the oscillating and perforated support surface S1 and the
transporter TR1 which conveyed the products. A wire (not shown) was
oscillated across the mouth of E1 by pneumatic piston PP1. As the
alginate sol was extruded through extrusion head E1 it was cut into
cherry-sized pieces by a wire oscillating across the mouth of the
extrusion head E1. The extrusion head E1 with an extrusion nozzle
of diameter 1.5 cm was positioned 2 cms below the surface of the
solution of calcium lactate. The aqueous alginate sol containing
dispersed cherry pulp was extruded at 6 cms/sec. The wire was
oscillated across the mouth of the nozzle to cut the extruded sol 4
times a second.
[0037] The cherry-sized pieces fell gently through the solution of
calcium lactate on to an oscillating perforated support surface S1
attaining a cherry-like shape and were transported out of the
solution of calcium lactate on a transporter TR1. Motors (i.e.
pneumatic pistons) MT1 and MT2 caused the support surface S1 to
oscillate horizontally and vertically, both at a frequency of 15
strokes a minute. The stroke length at the front of the support
surface was 35 mm. The stroke length at the rear of the support
surface was 27 mm. The angle from the vertical of the movement of
the support surface was 20 degrees. The support surface at the
highest point of its vertical oscillation was 4 cms below the
extrusion head. The support surface immediately under the extrusion
head was angled at 30 degrees to the horizontal. This was to avoid
products piling up under the nozzle. The support surface had an
array of circular perforations of 3 mm diameter spaced 6 mm apart.
The support surface S1 had a low rim to prevent the cherry-sized
pieces falling off other than on to the transporter TR1.
[0038] Details of the ingredients and mixtures used were as follows
(percentages are by weight):
1 % Syrup Fructose 32.25 Water 13.74 Colour 00.01 Total 46.00
Alginate slurry Sodium citrate 00.20 Sodium alginate 00.80 Glycerol
3.00 Total 4.00 Cherry mix Candied cherries 25.00 Citric acid 1.20
Sodium citrate 0.40 Fructose 22.79. Colour 0.01 Flavour 0.60 Total
50.00 Support matrix Fructose 75.00 Citric acid 1.20 Colour 0.02
Flavour 0.04 Water 23.38 Total 100.00
[0039] The equipment and process described above is, of course,
suitable for use with other compositions based on alginate or
low-methoxy pectate sols.
* * * * *