PROCESSED MUSHROOM PRODUCT

Abstract: A procedure for processing mushroom flesh is disclosed which includes the steps of: blanching the mushrooms to reduce their flavour content, reducing their moisture content to between 50 % and 75 % and mincing them. In this way a stable product is produced which can be combined with meat and/or vegetables to produce a rissole or pattie.

Description: PROCESSED MUSHROOM PRODUCT Technical Field The present invention relates to a processed mushroom product and a process for producing a processed mushroom product. 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 Agahcus bisporus; the Shiitake mushroom Lentinus edodes; and the oyster mushroom Pleurotus asticatus and Pleurotus coinucopical, but any other edible 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 volume is lost and water released, which tends to be detrimental to forming a relatively 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 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 that the water content of said mushrooms is reduced to between about 50% and 75%; and (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; 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 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 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 quicker drying. If it is desired to retain mushroom flavour, then it is preferred that the 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 of flavour is not required or desirable, then faster processes may be used, such as 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. 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, to be combined with red or white meat to form a pattie or cake, or to provide a 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 technology in a novel process applicable to mushroom products. Various alternative implementations are possible within the general inventive concept, as will be apparent to those skilled in the art. 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 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 used where it is desired to substantially remove the mushroom flavour. If the mushrooms are of a large size then, as shown by dotted paths 9 and 1 1 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. 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 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, 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 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 150g, 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 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 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 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 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. 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 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, 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 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 other materials as a meat extender, or flavoured as desired using appropriate artificial 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 density of flavour and texture, which may be used for any desired culinary purpose.

Claims: CLAIMS : 1. A process for manufacturing a mushroom product, including the steps of : (a) subjecting fresh mushrooms to a water content reduction process, so that the water content of said mushrooms is reduced to between 50% and 75%; and (b) mincing the product of step (a). 2. A process according to claim 1 , wherein said water content reduction process comprises one or more steps selected from the set comprising blanching, mechanical pressing, heat pump drying and fluidised bed drying. 3. A process according to claim 1 or claim 2, further comprising the step of combining the minced product with a binder to form a bound product. 4. A process according to claim 3, wherein said minced product is further admixed with one or more components selected from the set comprising minced meat, minced vegetables, flavourings, herbs, spices, and preservatives. 5. A process for manufacturing a mushroom product including the steps of : a) subjecting fresh mushrooms to blanching; b) reducing the moisture content of the blanched mushrooms to between 50% and 75%; c) mincing the product resulting from step b). 6. A process according to claim 5, wherein the blanching at step a) is performed at 90°C for a period of about 10 minutes. 7. A process according to claim 5, wherein the reduced moisture content of between 50% and 75% is achieved by the steps of drainining the blanched mushrooms and then subjecting them to a drying procedure. 8. A process according to claim 7, wherein the drying procedure comprises any one of the following : press drying, heat pump drying, fluidised bed drying. 9. A process according to claim 5, further including the step of : d) nitrogen flushing the minced product of step c) prior to packaging in order to minimise oxidative browning. 10. A process according to claim 9, further including the step of : e) packaging the nitrogen flushed product of step d) with an oxygen scavenger in order to further minimise oxidative browning. 11. A process according to claim 10, further including the step of : f) fast freezing the packaged product of step e). 12. A processed mushroom product produced by the process of any one of claims 5 to 11. 13. A mushroom product formed from minced moisture reduced mushrooms said mushrooms having a reduced water content of between about 50% and about 70%. 14. A mushroom product according to claim 13, further including a binder. 15. A mushroom product according to claim 13 or claim 14, wherein said product further includes one or more components selected from the set comprising minced meat, minced vegetables, flavourings, herbs, spices, and preservatives.

Inventors: LAWSON MARTIAL DI, WOODWARD PHILLIP RONALD, LAWSON, MARTIAL +DI, WOODWARD, PHILLIP, RONALD
Applicants: LAWSON MARION & LF, LILYVALE MUSHROOMS PTY LTD, WOODWARD PHILLIP RONALD, LAWSON, MARION +LF, LILYVALE MUSHROOMS PTY. LTD., WOODWARD, PHILLIP, RONALD
Application year: 1998
Main classification: A23L1
IPC codes: A23L1