Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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PROCESSFD MUSHROOM PRODUCT
Technical Field
The present invention relates to a processed mushroom product and a
process for producing a processed mushroom product.
5 Background Art
The mushroom is an edible fungi which has increasingly become a staple
cultivated product available year round throughout the developed world. By
mushroom is meant principally the cultivated mushroom, for example the button
mushroom Agaricus bisporus; the Shiitake mushroom Lentinus edodes; and the
10 oyster mushroom Pleurotus astlcatus and Pleurotvs coinucopical, but any otheredible fungus is potentially a raw material according to the present invention.
Mushrooms have not been widely processed in order to produce other
food products. One reason for this is that during cooking a great deal of volumeis lost and water released, which tends to be detrimental to forming a relatively
15 firm or solid product. Mushrooms are used in a pureed form for the manufacture
of soups and the like, where texture is not required from the mushrooms
themselves. If fresh mushrooms are simply minced, a wet slurry is formed.
It is an object of the present invention to provide a mushroom product
which is capable of being formed into a pattie or the like, either alone or in
20 combination with other ingredients, and a process for making such a product.
Summary of Invention
According to one aspect the present invention provides a mushroom
product formed from minced moisture reduced mushrooms, said mushrooms
having a reduced water content of between about 50% and about 70%.
Preferably, the mushroom product further includes a suitable binder, most
preferably egg white.
According to another aspect, the present invention provides a process for
manufacturing a mushroom product, including the steps of:
(a) subjecting fresh mushrooms to a water content reduction process, so
30 that the water content of said mushrooms is reduced to between about 50% and
75%; and
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(b) mincing the product of step (a).
Optionally, the process may further include a step of mixing in a suitable
binder or other additives, additional drying steps and mincing, and forming the
product into predefined shapes, such as patties or an extrusion.
The drying process may be preceded by slicing and/or blanching steps in
order to improve drying efficiency and reduce any pathogen concentration.
According to a further aspect of the invention there is provided a process
for manufacturing a mushroom product including the steps of:
a) subjecting fresh mushrooms to blanching;
10 b) reducing the moisture content of the blanched mushrooms to between
50% and 75%; and
c) mincing the product resulting from step b).
The inventors have determined that by reducing the moisture content of
fresh mushrooms, and then mincing, that a relatively coherent material is
15 produced with a consistency not unlike minced meat, and that when the material
is cooked, for example in the manner of a hamburger, it retains its shape and
form well, and has a cooked texture and mouth feel comparable to meat. It is
believed that the inventive process allows the mushroom mycelium fibres to be
better preserved and so provide meat-like texture to the processed product.
Further, the present invention is applicable to damaged mushrooms, and
stalks, which are otherwise treated as a waste material. These materials
produce a processed product of comparable or superior quality to good quality
mushroom caps.
By including a step of blanching the mushroom meat it is possible to
25 remove water soluble flavour and aroma constituents from the mushroom flesh
thereby producing a final product which has a bland product taste.
The mushrooms may be dried by any suitable process. The mushrooms
may be sliced or otherwise reduced in size prior to drying to facilitate quickerdrying. If it is desired to retain mushroom flavour, then it is preferred that the
30 drying process be one in which loss of flavour and texture is minimised. A
preferred technique is heat pump type drying systems. Alternatively, if retention
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of flavour is not required or desirable, then faster processes may be used, suchas fluidised bed type systems. A mechanical drying process, such as a screw or
roller press, may also be used in addition to, or as an alternative to, the other
processes.
The dried mushrooms are preferably minced to a size similar to minced or
ground beef, although any suitable size may be used, with variations in the
physical properties of the product as would be understood.
If a pattie is to be formed, it is preferred that a binder, illustratively egg
white, is used, and that the pattie be formed using any conventional process.
10 Other additives, such as preservatives or flavourings, may be added if desired
but are not essential.
It will be appreciated that the product of the inventive process may be
used as an ingredient in the production of other food products - for example, tobe combined with red or white meat to form a pattie or cake, or to provide a
15 bland base material with similar organoleptic properties to meat which can be flavoured to produce a topping for pizzas or the like.
Brief Description of Figures
An illustrative process for producing a mushroom product will now be
described in more details with reference to the accompanying figures, in which:
Figure 1 is a flowchart illustrating one implementation of the present
invention; and
Figure 2 is a flowchart illustrating a second implementation of the present
invention.
Detailed Description
It will be appreciated that the process of the present invention may be
implemented with conventional food processing machinery, which is widely in
use. In particular the inventors have found screw or belt presses to be
particularly suitable. The inventive concept relates to applying this technologyin a novel process applicable to mushroom products. Various alternative
30 implementations are possible within the general inventive concept, as will be apparent to those skilled in the art.
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Referring now to Figure 1 there is depicted a block diagram of a process
for manufacturing mushroom product according to the present invention. At box
1 of the flowchart it is seen that the mushrooms are first to be washed. The
washing may be done by any conventional conveyor type process, or through
5 drum washing.
The mushrooms are then blanched at box 3 using a steam or hot water
system. Using the steam system, typically four to ten minutes of blanching are
required with the lower end of that range being used where it is desired that the
mushrooms retain to some extent their flavour and longer blanch times being
10 used where it is desired to substantially remove the mushroom flavour. If themushrooms are of a large size then, as shown by dotted paths 9 and 11 to box
5, the mushrooms may be sliced or otherwise reduced in size prior to blanching.
The blanched product is then reduced in moisture further by using a
screw press or similar mechanical device as indicated at box 7.
The product is then minced as indicated by box 13. Mincing is preferably
through a mincing disc having holes of 4mm to 6mm diameter or by use of a
meat grinder. The mechanism is essentially that used for producing ground
beef or the like.
The product is then passed to a drying system as indicated by box 15.
20 The drying system may for example be of the heat pump type. In such systems,
a compressor blows air over the product, which air is then recirculated through
coils to remove moisture, then heated and again blown over the product.
Typically, this process takes place at 45~C to 55~C. The above described heat-
pump procedure has been determined to be particularly useful in retaining
25 maximum flavour. Ideally, the product is dried to between 50% and 75% of its
original moisture content. If the product is insufficiently dried, then when minced
and formed into a pattie it will be too moist; if it is excessively dried, then the
product becomes somewhat stiff in texture.
The minced product is then, if it is to be formed into a pattie,
30 agglomerated with a suitable binder, as indicated at box 17, and optionally
flavour enhancing additives, preservatives, and the like may be added as is well
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understood in the food technology art. These components may include minced
meat or vegetables, herbs, spices, flavours, preservatives, and the like. A typical
pattie produced may be approximately 1509, and when cooked have a texture
not unlike a rissole or hamburger pattie.
It will be understood by the skilled in the art that the process will need to
be modified depending upon the condition of the product used, and based upon
the type of mushroom used. For example highly flavoured mushrooms will
require longer blanching times in order to substantially remove their flavour than
less highly flavoured mushrooms.
A suitable binder is egg white, although any suitable binder may be used.
The binder may vary with the end use intended. Also, the addition of other
components such as meat may vary the required characteristics of the binder.
Figure 2 illustrates a further implementation of the present invention
wherein it is specifically intended that the finished product be largely devoid of
15 mushroom flavour. The mushrooms to be processed are first spray washed, as
indicated at box 21 to remove growth media, such as peat and compost
contaminants from the stalks and caps of the mushroom. Next, at box 23 the
washed mushrooms are subjected to steam or water blanching for 10 minutes at
90~C. By blanching for this length of time it is possible to remove water soluble
20 flavour and aroma constituents from the mushroom flesh thereby producing a
final product which has a bland product taste. Apart from the removal of odour
and flavour constituents, blanching also reduces the microbial load present on
the raw mushrooms and deactivates any enzymes which may be present.
Additionally, it is believed that blanching produces a change in the elasticity of
25 the cell structure so that the mushroom flesh is able retain a degree of structure
whilst being subjected to subsequent drying and mincing steps of the process.
In particular, the blanching process toughens the cells so that they are better
able to withstand pressing and mincing, the longer heat treatment producing a
rubbery texture in the blanched mushrooms. It is believed that such toughening
30 is due to the removal of free water from the cells, reduction in air held in the
tissues, and changes in the chemistry of the cells and cell walls.
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At box 25 the blanched mushrooms are drained, for example on a
vibrating screen, as a first step towards drying them. Then at box 27 they are
subjected to press-drying, for example by means of a roller-press until the
moisture content has been reduced to 50-75%. Following the drying stage the
5 mushrooms are minced at box 29. At box 31 the thus far processed mushroom
meat is subjected to nitrogen flushing to eliminate oxygen. This step has been
found to reduce the problem of the processed mushroom browning. An effect
which is believed to be caused by oxidation.
As indicated at box 33 the processed mushroom is then packaged,
10 preferably with a suitable oxygen scavenger, such scavengers are well known
in the food technology art, in order to further reduce the likelihood of oxidative
browning.
The packaged product is then frozen, preferably by means of a fast
freezing process in order to minimise mushroom cell rupture due to ice crystal
15 formation within the product.
The product of the present invention may be applied in a number of ways.
If a system is used in which volatile flavour components are not retained, as will
be achieved by using an extended blanching time, then a generally tasteless
material with a meat-like texture can be produced which can be combined with
20 other materials as a meat extender, or flavoured as desired using appropriateartificial or natural flavours. If the taste components are largely retained, a
mushroom flavoured product can be produced, either as mushroom alone or
combined with other components or flavours.
The present invention accordingly provides a product which has a good
25 density of flavour and texture, which may be used for any desired culinary
purpose.
