Methods for producing food from fermented by-products of food production

Abstract

Methods for the production of foodstuffs with the following steps - Pasteurizing a raw material that is a by-product of food production to produce a pasteurized raw material, - Inoculation of the pasteurized raw material with at least one edible basidiomycete and aerobic fermentation of the water-suspended pasteurized raw material in a submerged process to produce a fermenter broth containing mycelium of at least one basidiomycete, - Introducing the entire fermentation broth as an ingredient into an extruder, - Introducing at least one vegetable protein mixture containing vegetable flour selected from protein concentrates, protein isolates or flour made from pumpkin seeds, broad beans, peas, sunflowers or cereals and mixtures of at least two of these, as an ingredient into the extruder, - and extruding the ingredients, whereby the ingredients reach a temperature of at least 65°C, to produce a mass, and before or after the mass exits the extruder, cooling the mass to produce the food.

Description

[0001] The present invention relates to a process for producing foodstuffs, preferably free of animal components, from raw materials that are by-products of food production, by means of fermentation. The process is characterized in that it can produce foodstuffs with few process steps, using as starting materials, among others, raw materials that are by-products of food production and which therefore have not themselves entered the food product.

[0002] Currently, by-products from food production, such as peels from potatoes, fruit, nuts or grains, are used as animal feed, burned after drying or fermented to produce biogas.

[0003] WO 2020 / 061502 A1 describes an aerobic fermentation process using fungal mycelium for the production of meat analogues. In this process, a filamentous fungus is cultivated in a nutrient medium, harvested, optionally pasteurized, extruded, and dried. The nutrient medium can be a by-product of food production. After fermentation, the fungal mycelium is isolated and dewatered, and only the dewatered biomass is used as food.

[0004] US Patent 2009 / 0148558 A1 describes a process for producing meat analogues from fungal mycelium cultivated in a synthetic nutrient broth consisting of potato dextrose broth (PDB), yeast extract, malt extract, and soytone. The mycelium is isolated before being mixed with protein and binder and extruded.

[0005] EP 3 942 937 A1 describes the production of a fibrous fungal mass by cultivating Rhizopus in a submerged fermentation process in a sugar solution, heating to 50 to 75 °C for up to 1 hour, and separating the water (paragraph 39) to produce a pure fungal biomass. The aqueous phase of the fermentation broth is not used as an ingredient in a food product; only the separated mycelium is used.

[0006] US 2022 / 0030911 A1 describes the production of a foodstuff by fermenting vegetable protein flours in aqueous suspension with a fungus to reduce bitter and bean flavors, optionally with subsequent extrusion.

[0007] EP 3 270 716 B1 describes a process for producing a meat substitute strand by extruding a mixture of a maximum of 4 wt.% flour, 40-70 wt.% water and 15-35 wt.% vegetable protein through a cooling die, wherein 2-15 wt.% oil and / or fat are fed downstream of the extruder inlet.

[0008] EP 3 621 463 B1 describes a cooling nozzle that is connected to the outlet of an extruder to produce food from extruded masses based on plant protein.

[0009] DE 26 03 406 A1 describes a process for producing a strand with a meat-like texture by extruding a mixture with 5-50 wt% single-cell protein material and 20-45% moisture content at 99-196 °C, drying at 54-177 °C, and optionally rolling and cooling the extrudate.

[0010] The object of the invention is to provide a process for the production of foodstuffs that uses by-products of food production as raw materials. Preferably, the process should produce from the raw materials used, which cannot themselves be directly mixed into foodstuffs, an ingredient that closely resembles conventional foods and which can be extruded with plant protein mixtures to form a solid foodstuff. The process should preferably be feasible without the breeding of insects and without the use of insects as raw materials or ingredients.

[0011] The invention solves the problem with the features of the claims and in particular provides a process for the production of foodstuffs that combines the fermentation of by-products from food production with the wet extrusion of plant protein mixtures. The process comprises the steps - Pasteurizing or sterilizing a raw material that is a by-product of food production to produce a pasteurized or sterilized raw material, - Inoculation of the sterilized raw material with mycelium of at least one basidiomycete and aerobic fermentation of the pasteurized or sterilized raw material suspended in water using a submerged fermentation process, e.g. for a duration of 5 to 15 days, to produce a fermentation broth with a mycelium content of at least one basidiomycete. - Introducing the complete fermentation broth and a plant protein mixture as ingredients into an extruder - and extruding the ingredients, whereby the ingredients reach a temperature of at least 65°C, to produce a mass, and before or after the mass exits the extruder, cooling the mass to produce the food, e.g. to a maximum of 20°C.

[0012] According to the invention, no water is added to the ingredients in addition to the fermentation broth, so that the fermentation broth alone forms the liquid ingredient of the composition that is introduced into the extruder.

[0013] Pasteurization or sterilization of the raw material is carried out to such an extent that any bacteria and yeasts contained in the raw material are inactivated. Sterilization can be achieved through heat treatment, e.g., for 20 minutes at 121°C, e.g., by steam injection; through static high-pressure treatment, e.g., at 4000 to 6000 bar for 1 to 10 minutes; through treatment with pulsed electric fields; or a combination of at least two of these methods.

[0014] The raw material can be suspended in water before or after pasteurization or sterilization.

[0015] Inoculation of the raw material with basidiomycetes can take place before or after the sterilized raw material is suspended in water, e.g., by mixing in spores or mycelium of at least one basidiomycete. Preferably, inoculation with mycelium of the at least one basidiomycete is carried out in a ratio of 1:5 to 1:25, e.g., 1:10 to 1:20 vol / vol to the raw material or to the raw material suspended in water. The mycelium used for inoculation is preferably produced by aerobic submerged fermentation, e.g., in an aqueous nutrient medium that is synthetic and / or an aqueous suspension of a raw material used according to the invention, wherein the aqueous nutrient medium is preferably sterilized.

[0016] For sterilization, the raw material or medium can be autoclaved, e.g. treated at 121°C for at least 15 minutes.

[0017] It has been shown that pasteurizing the raw material before inoculation is sufficient, e.g., by pasteurizing at 68 °C for 20 to 60 minutes, as this prevents the at least one basidiomycete from being suppressed by bacteria or other fungi after inoculation, e.g., from being overgrown, and preferably from being contaminated by bacteria or other fungi. Preferably, the mycelium used for inoculation is comminuted before inoculation, e.g., by intensive shearing, such as with an Ultra-Turrax at 6400 to 13000 rpm for 3 to 30 seconds, particularly intensive shearing immediately before inoculation, e.g., within a maximum of 10 minutes or a maximum of 5 minutes before inoculation. The intensive shearing is carried out until the mycelium intended for inoculation is comminuted into individual hyphae or aggregates of a maximum of 10 hyphae, preferably a maximum of 5 or a maximum of 3 hyphae, as can be determined, e.g., by microscopic inspection.

[0018] Preferably, the raw material has a dry matter content of 3 to 40 wt%, more preferably 20 to 40 wt% or 20 to 30 wt% in the aqueous suspension. It has been shown that with such a proportion of the raw material in the aqueous suspension, the fermentation broth produced during or before inoculation is essentially composed of pumpable mycelium, with little or no free aqueous content. The mycelium produced has, for example, a dry matter content of approximately 10 to 30 g / L.

[0019] Submerged fermentation takes place, for example, in a closed vessel, also referred to here as a reactor, which is aerated with low-germ or sterile air, while the raw material suspended in water is mixed with a stirrer or solely by aeration. Aeration preferably continues until the dissolved oxygen concentration reaches at least 10%, preferably at least 20%. The stirrer can be a turbine, propeller, or armature stirrer. Preferably, the vessel includes a temperature control device, in particular a cooling device. The vessel in which the fermentation takes place can, for example, be cooled to maintain a constant temperature of 15°C to 30°C for the fermentation broth during fermentation.

[0020] Preferably, aeration facilitates mixing. More preferably, the vessel does not have a mechanically or magnetically driven stirrer. It has been shown that the at least one basidiomycete, particularly if it has been fragmented by shearing prior to inoculation, is not overgrown or affected by other microorganisms even when aerated with non-sterile air, and preferably, the at least one basidiomycete suppresses other microorganisms. Fermentation can more preferably take place in an open vessel. Optionally, the vessel is temperature-controlled, and in particular cooled, solely at its outer wall by ambient air.

[0021] It has been shown that basidiomycetes in submerged culture essentially decompose the raw materials used, e.g., cellulose, lignocellulose, and hemicellulose from by-products of food production, and that the fermentation broth preferably consists of mycelium, optionally mixed with an aqueous fraction. The aqueous fraction can be introduced, at least partially, into the extruder as an ingredient, e.g., in the form of the portion of the fermentation broth containing the mycelium, after optionally separating off a portion of the aqueous fraction.

[0022] Fermentation is preferably carried out until the aqueous fraction of the fermenter broth contains no residues of the sterilized raw materials that are still visible after extrusion. In particular, fermentation is carried out until the basidiomycete has degraded the raw materials at least to the point that their residues have a maximum size of 1 mm, preferably a maximum of 0.5 mm or a maximum of 0.2 mm. Preferably, fermentation is continued until the raw material is completely degraded, or the fermenter broth is only drawn off when the raw material has been completely degraded.

[0023] Generally, the aqueous fraction of the fermenter broth remaining after mycelium removal can be sieved to remove particles larger than 1 mm, preferably 0.5 mm or 0.2 mm. Optionally, a portion of the aqueous fraction can be fed into the extruder without particle removal, as basidiomycetes will have decomposed all particles of the sterilized raw materials by the end of fermentation.

[0024] Generally, fermentation is preferred as a batch or fed-batch process. In the batch process, the entire raw material is placed in containers, inoculated, and fermented with aeration, without adding any further raw material before the mycelium is removed. In the fed-batch process, only a portion of the raw material is placed in containers, inoculated, and fermented with aeration, with additional raw material optionally added in batches or continuously until the mycelium is removed.

[0025] In a preferred embodiment, the fermentation is carried out as a batch process in an open container, wherein the aeration introduced into the container simultaneously forms a stirring device or performs a stirring function, and the container does not have an additional driven mechanical stirrer.

[0026] Fermentation with basidiomycetes preferably results in a fermentation broth with mycelium that contains no bitter substances, even with raw materials containing bitter compounds. This is because basidiomycetes can be used that break down bitter compounds, for example through hydrolysis or oxidative degradation.

[0027] It has been shown that extruding mycelium produced by the aerobic submerged fermentation of at least one basidiomycete, in mixture with at least one plant protein mixture, optionally starch and / or at least one thickening agent, can give the extruded mass a fibrous structure.

[0028] Preferably, after reaching at least 65°C, the mass is then cooled in the extruder or in a cooling nozzle connected to the extruder in order to retain the volatile aroma compounds of the basidiomycetes contained in the fermenter broth and the mycelium in the mass.

[0029] At least one basidiomycete is generally an edible basidiomycete, especially a food mushroom, and can be found, for example, under Pleurotaceae, especially Pleurotus ostreatus (Oyster Mushroom), Pleurotus eryngii (Brown Oyster Mushroom), Pleurotus pulmonarius (Chestnut Mushroom), Pleurotus citrinopileatus (Lemon Oyster Mushroom), Pleurotus salmoneo-stramineus (Pink Oyster Mushroom), Omphalotaceae, especially Lentinus edodes (Shiitake), Physalacriaceae, especially Flammulina velutipes (Velvet Foot Mushroom), Agaricaceae, especially Macrolepiota procera (Parasol Mushroom), Agaricus bisporus (Button Mushroom), Agaricus arvensis (Anise Mushroom), Strophariaceae, especially Kuehneromyces mutabilis (Sheep's Tail Mushroom), Stropharia rugosoannulata (Giant False Fungus), Pholiota nameko (Golden Cap, Nameko), Bolbitiaceae, especially Agrocybe aegerita (Southern Field Mushroom), Lyophyllaceae, especially Hypsizygus ulmarius (Elm Fungus), Hypsizygus tessulatus (Beech Fungus, Shimeji), Tricholomataceae, especially Lepista nuda (Violet Blewit), Boletaceae, especially Boletus edulis (Porcini), Boletus pinicola, Boletus aereus, Cantharellaceae, especially Cantharellus cibarius (Chanterelle), Polyporaceae, especially Pleurotus sajor-caju (Grey Oyster Mushroom), Laetiporaceae, especially Laetiporus sulphureus (Sulfur Polypore), Grifolaceae, especially Grifola frondosa, Auriculariaceae, especially Auricularia auricula-judae, Hericiaceae, especially Hericium erinaceus, Taxonomically related species and combinations of at least two of these must be selected.

[0030] The yellow to orange-red color of the extruded mass is primarily due to one of the basidiomycetes, Laetiporus sulphureus, as it also produces orange-red laetiporic acids during submerged fermentation.

[0031] The raw material, which is a byproduct of food production, is preferably one or at least two selected from: - Stems of edible mushrooms that are produced as a byproduct during fruiting body production, - Cereal and legume straw, - Sugar beet pulp, especially after sugar extraction, - Cereal bran, e.g. wheat bran, corn bran and rice bran, - Potato peels, apple peels, grape skins, citrus peels and carrot peels, - Cauliflower trimmings, leek greens, - extracted tea leaves, - Press cake from edible oil production, in particular rapeseed press cake, soybean press cake and olive press cake, - empty sunflower blossoms, sunflower shells, - Nut shells, optionally ground or unground, - Corn cobs after the kernels have been removed, - red peanut shells, - spent grain, - Grape pomace, optionally after distillation of alcohol, such as after the production of grappa, - Sugarcane bagasse, sugarcane leaves, - Coffee grounds, e.g. after aqueous extraction and / or after caffeine extraction, - Back bread, - Banana leaves and mixtures of at least two of these.

[0032] The plant-based protein mixture can have particle sizes ranging from grits, meal, and flour to fine flour. Generally, the plant-based protein mixture can contain plant-based flour with, based on dry matter, 35 to 85 wt%, preferably at least 45 wt%, more preferably 60 wt%, and more preferably at least 70 wt%, e.g., up to 82 wt% or up to 75 wt% plant-based protein, as well as starch and plant fibers. Optionally, plant-based fat, solid or liquid, is added to the plant-based protein mixture. Optionally, the plant-based protein mixture consists of plant-based flours.

[0033] The plant-based protein mixture comprises plant-based flour, e.g., pumpkin seed flour, cereal protein, in particular oat protein, broad bean protein, pea protein, or sunflower protein, or a mixture of at least two of these. Preferably, the plant-based protein mixture comprises protein concentrates or protein isolates, e.g., flour, protein concentrate, or protein isolate from pumpkin seed flour, broad bean flour, pea flour, sunflower flour, or cereal protein isolate. A preferred plant-based protein mixture consists of pumpkin seed flour (protein content approximately 60 g / 100 g), sunflower protein (protein content approximately 48 g / 100 g), and pea protein (protein content approximately 82 g / 100 g) with a total protein content of, for example, 78 to Preferably 81 wt.% protein, 6 wt.% glycerol and additives, e.g. 6 wt.% tomato mixture, 3 wt.% caramel and 4 wt.% salt. Generally, the vegetable flours and the vegetable protein mixture thereof are preferably free-flowing, especially in powder form.

[0034] Additives include flavorings, salt and colorings, e.g. liquid smoke or smoke flavoring, meat flavoring, caramel coloring, caramel, e.g. liquid or as powdered instant caramel, tomato paste, tomato mixture, vegetable colorings, spices, yeast extract, preferably excluding yeast extract.

[0035] Optionally, the ingredients do not contain any thickener, in particular no thickener from the group which contains or consists of carbohydrate polymers, e.g. starch, modified starch, gums, e.g. guar gum, guar gum, cellulose, cellulose derivatives, carboxymethylcellulose, xanthan gum, pectin, alginate, locust bean gum, and / or carrageenan.

[0036] Optionally, the ingredients may contain added plant fibers, e.g. pea fiber, apple fiber, cereal fiber.

[0037] Optionally, the ingredients may contain added starch; preferably, the mixture of ingredients contains no added starch but only the starch content naturally present in the vegetable flours, which may be protein concentrate and / or protein isolate. Optionally, the mixture of ingredients contains soy protein and / or wheat gluten; preferably, the protein mixture is free of soy protein and / or wheat gluten.

[0038] The fat may be selected from rapeseed oil, sunflower oil, olive oil, soybean oil, nut oil, cocoa butter, cottonseed oil, sesame oil, milk fat, butter and / or refined butterfat that is liquid above 20°C. Generally, the fat is preferred if it is liquid above 0°C and solid below 0°C.

[0039] The addition of vegetable fat, liquid or solid, and optionally the addition of additives, e.g. flavorings, salt and colorings, to the extruder preferably takes place downstream of its inlet end, more preferably downstream of the addition of water or aqueous portion of the fermentation broth.

[0040] During extrusion, the mixture of ingredients is heated in a section of the extruder to a temperature of 110 to 150 °C, preferably 120 to 140 °C, and subjected to a pressure that, for example, prevents the formation of vapor bubbles, preferably a pressure of at least 4 bar or at least 6 bar, e.g. up to 30 bar, up to 25 bar, up to 28 bar or up to 20 bar, wherein preferably optionally the extruder is cooled in the section upstream of the second feed nozzle in order to cool the mass to a temperature of a maximum of 125 °C, e.g. a temperature of 110 °C or from 115 °C to 122 °C or up to 121 °C or up to 120 °C, e.g. 118 °C to 121 °C.

[0041] Extrusion is preferably carried out using the following steps: - Mixing powdered proteins from plant sources and optionally other ingredients, e.g., yeast flakes, fibers, optionally a first portion of the fermentation broth and / or water, to produce a plant protein mixture, which is preferably free-flowing, wherein the plant protein mixture preferably contains at least 35 to 85 wt.%, preferably at least 60 wt.%, more preferably at least 70 wt.%, e.g., up to 82 wt.% or up to 75 wt.% plant protein, - Feeding the plant protein mixture into the feed end of an extruder, - Adding fermentation broth to the extruder through a first feed nozzle of the extruder, which is arranged downstream of the inlet end of the extruder, wherein the protein mixture including the fermentation broth preferably adds water to the total. containing a maximum of 30 wt.% to 60 wt.% of the protein mass exiting the extruder, - optional addition of further ingredients downstream of the inlet end, in particular by means of a The second feed nozzle is located downstream of the first feed nozzle on the extruder. - wherein the protein mixture is heated in a section of the extruder to a temperature of 110 to 150 °C, preferably 120 to 140 °C, and is subjected to a pressure that, for example, prevents the formation of vapor bubbles, preferably a pressure of at least 4 bar or at least 6 bar, e.g. up to 30 bar, up to 25 bar, up to 28 bar or up to 20 bar, - wherein preferably optionally the extruder is cooled in the section upstream of the second feed nozzle to cool the mass to a maximum temperature of 125 °C, e.g. a temperature of 110 °C or from 115 °C to 122 °C or to 121 °C or to 120 °C, e.g. 118 °C to 121 °C, - Shaping and cooling the protein mass exiting the extruder, e.g. to a temperature of 30 to 80 °C, in particular by means of a cooling nozzle connected to the extruder.

[0042] In this process, the total protein content of the protein mass is determined by the plant protein, the protein content of the other ingredients, and the protein content of the fermentation broth.

[0043] The other ingredients may be selected from, for example, edible fats and oils, flavorings, colorings, table salt and mixtures of at least two of these.

[0044] A device set up to carry out the process generally includes a reactor and an extruder, and optionally a mixing chamber arranged downstream of the reactor and upstream of the extruder.

[0045] It is generally preferred that the reactor has a reactor vessel open at one end and a matching, removable lid, which together enclose an interior space of the reactor. The reactor vessel has a bottom wall and a circumferential side wall fully connected to the bottom wall, with the bottom wall preferably forming a first end of the reactor and the lid a second end opposite it, the longitudinal axis of the reactor being formed between them. It is generally preferred that the reactor vessel is made of plastic and the lid of stainless steel, or alternatively, that both are made of plastic, preferably with a non-stick surface and / or with an antimicrobial coating, e.g., plasma-treated surfaces, Teflon coatings, ceramic coatings, glass coatings, silver-additive-based epoxy or polyurethane coatings, or the like.

[0046] Preferably the cross-section of the reactor is constant over its length, further preferably oval or circular, alternatively rectangular, preferably with rounded corners.

[0047] Optionally, the reactor vessel wall, i.e., the surrounding side wall and the bottom wall, can be designed without openings, penetrations, or perforations. This offers the advantage of making the reactor easy to clean and disinfect, and reducing the accumulation of contaminants.

[0048] The lid is generally preferably configured to completely seal the reactor, e.g., by means of a screw, magnetic, or latch closure, and the lid generally preferably has the same cross-section as the reactor vessel. Generally, the lid has at least one opening, which is / are configured to form at least one sealed passage for at least one device.

[0049] Optionally, all components can be routed through the lid. It is preferred that the components are fixed and immovable, and generally sealed and / or sterilizable, and that the lid, together with the components routed through it, is removable and cleanable, in particular autoclavable and / or dishwasher-washable. This gives the reactor the advantage of being easy to clean and disinfect.

[0050] The at least one device preferably guided through the lid is preferably selected from the group comprising heat exchangers, e.g. heating rods, ventilation lances (also for use with hot steam for pasteurization), stirrers, valves such as pressure relief valves, sensors for e.g. pH value, temperature or especially for dissolved oxygen, sampling tubes, inoculation tubes, e.g. for adding spores or mycelium of at least one basidiomycete or ascomycete, wherein the sampling tubes and inoculation tubes are each preferably designed as a ball valve or one-way valve.

[0051] The reactor preferably includes a heat exchanger, e.g., a heating element, configured to generate heat for pasteurizing or sterilizing all raw materials in the reactor, particularly by heating them to at least 68 °C or at least 121 °C for at least 20 minutes or longer. More preferably, the heat exchanger is configured to cool the raw material and / or the fermenting raw material and / or the fermentation broth, e.g., to a temperature of 15 to 30 °C. The heat exchanger is preferably routed through the reactor lid or, alternatively, can be arranged on or through the reactor wall.

[0052] Furthermore, the reactor comprises at least one ventilation lance, preferably at least two, at least four, or at least eight ventilation lances, e.g., up to 32 or up to 16 ventilation lances, each with at least two aligned air outlets, designed to stir or mix the reactor's internal volume by blowing in air. The stirring motion of the raw material or fermenter broth generated by the at least one ventilation lance can be swirling or turbulent.

[0053] Optionally, the reactor has no movable stirrer and is set up to stir the raw material only by blown-in air.

[0054] The air blown into the reactor through at least one ventilation lance can be filtered and / or enriched with moisture. Generally, at least one ventilation lance is connected to a compressor, optionally with an attached air filter, the compressor preferably being configured to generate an air pressure of at least 6 bar, preferably at least 8 bar, e.g., up to 30 bar.

[0055] At least one ventilation lance may have curves, e.g. hooks or spirals, or may be designed without curves.

[0056] In a first embodiment, the at least one ventilation lance can have, following the opening in the lid, a straight first section which, when the lid is in place as a closure for the reactor vessel, projects towards the bottom wall, and subsequently a curved second section, e.g., formed as a spiral, which, when the lid is in place as a closure for the reactor vessel, is arranged at a distance of, e.g., 0.5 to 2 cm from the bottom wall and preferably parallel to it. In this case, the outlet openings of the ventilation lance are preferably oriented towards the lid, and the stirring motion of the raw material or fermenter broth generated by the at least one ventilation lance is a laminar motion produced by rising air bubbles.

[0057] In a second embodiment, the reactor can have at least two, preferably at least four, ventilation lances, which are preferably all straight and, when the lid is arranged as the closure of the reactor vessel, project into the reactor, for example, parallel to or at an angle to the longitudinal axis of the reactor. The outlet openings of these lances are each oriented at an angle of at least 0° to 90° to the nearest section of the surrounding side wall. In this case, the stirring motion of the raw material or fermenter broth caused by the at least one ventilation lance is preferably a swirling or spiral motion generated by horizontally or obliquely injected air bubbles. In this embodiment, it is preferred that the at least two ventilation lances are arranged at a smaller distance from the surrounding side wall than other devices, in particular pressure relief valves, heating elements, sensors, and probes that pass through the lid.

[0058] It is preferred that the optional mixing chamber has a container with a first and a second inlet, wherein the first inlet is preferably configured for feeding in the fermentation broth and the second inlet for feeding in the plant protein mixture. The first and second inlets can be formed independently of each other or simultaneously by pipes, optionally with a conveying device arranged therein, e.g., a metering screw or a hopper for the plant protein mixture and / or a pump for the fermentation broth, or, e.g., by openings in the container through which the fermentation broth or the plant protein mixture can be introduced, e.g., by pouring or tipping.

[0059] The optional mixing chamber is set up, the vegetable protein mixture and the complete Fermenter broth, optionally including all fermenter broths from fermentations with various side streams and / or with various basidiomycetes, in particular the fermenter broth(s). and to take up and store or incubate the plant protein mixture sequentially or simultaneously, preferably at a controlled temperature.

[0060] The optional mixing chamber can be heated and / or cooled, in particular to a temperature of 5 to 40 °C, preferably to 10 to 30 °C or down to 20 °C, e.g. by means of a heat exchanger, and / or can have a mixing device, e.g. a stirrer or a magnetic stirrer.

[0061] The optional mixing chamber can be directly connected to the inlet end of the extruder, e.g. via a pipe, preferably with a conveying device arranged therein, e.g. a pump.

[0062] The extruder is preferably a screw extruder with at least one screw, preferably at least two screws. In particular, the extruder can be a planetary roller extruder.

[0063] The extruder preferably extends from an inlet end to an opposite outlet end, with at least three intermediate sections that can be heated and / or cooled independently of one another, e.g., by means of a double jacket arranged on the stator and / or the at least one screw of the extruder, through which a temperature control medium flows, or by an electric heater. At its inlet end, the extruder has an inlet that can be connected to the reactor or, optionally, to the mixing chamber.

[0064] In general, the extruder is set up to heat a plant protein mixture filled into its inlet to a temperature of at least 65 °C in a section of the extruder and preferably to subject it to a pressure of at least 4 bar.

[0065] For example, a first section of the extruder adjacent to the inlet end, which preferably has a first feed nozzle, can be unheated or heated to a first temperature, e.g., to a temperature of at least 40°C or at least or up to 65°C, and a second section of the extruder adjacent downstream thereto can be heated to a second temperature higher than the first temperature, e.g., 110 to 150°C, preferably 120 to 140°C, a third section adjacent downstream thereto can be cooled to a third temperature lower than the second temperature, e.g., 110°C or from 115°C to 122°C or up to 121°C, e.g., 118°C to 121°C, and an optional fourth section, which preferably has a second feed nozzle, can be cooled to a fourth temperature lower than the third temperature, e.g., a maximum of 100°C, e.g., 30 to 80°C It must be chilled, or it may not be at room temperature.

[0066] It is generally preferred that the outlet of the extruder, which follows the third or optionally fourth section of the extruder at the discharge end, is designed as a cooling nozzle, which is preferably configured to cool the protein mass exiting the extruder to a temperature of 60 to 100 °C, preferably 89 to 90 °C.

[0067] The invention will now be explained using examples and with reference to the figures shown in - Fig. 1 schematically the cross-section of the lid of a reactor of a first embodiment, - Fig. 2 schematically the cover of a reactor of a second embodiment in cross-section and - Fig. Figure 3 schematically shows the cross-section of the lid of a reactor of a first embodiment.

[0068] The lids shown schematically in the figures have guides formed as perforations, each represented as a round, black, closed line. Ventilation and / or hot steam lances 1 are arranged with their outlet openings in the direction of the arrows, so that the raw material is stirred when air is blown into the reactor. Excess air can escape from the reactor via pressure relief valves 2. Raw material or fermenter broth can be extracted from the reactor interior via sampling probes 3. The broth inside the reactor can be tested for parameters such as temperature, pH value, or dissolved oxygen using measuring sensors 4. The raw material can be inoculated via inoculation probes 5, for example, with mycelium of a basidiomycete.

[0069] The in Fig. The cover, shown schematically, has a round cross-section and two ventilation and / or hot steam lances, the outlet openings of which are arranged approximately parallel to the surrounding side wall, so that a vortex-like mixing effect is achieved when air is blown in. In addition, a pressure relief valve is routed through the cover, as well as a sampling probe 3, a measuring sensor 4, and an injection probe 5.

[0070] The in Fig. The lid shown in Figure 2 has a rectangular cross-section with rounded corners and features 12 ventilation and / or hot steam lances 1, the outlet openings of which are oriented at an angle of 15° to 90° to the nearest section of the surrounding side wall, so that a spiral mixing effect is achieved when air is blown in. In addition, 4 pressure relief valves 2 are routed through the lid, allowing air to escape from the reactor interior, as well as a sampling probe 3, a measuring sensor 4, and an inoculation probe 5.

[0071] Fig. Figure 3 shows a lid with a square cross-section, which has four ventilation and / or hot steam lances 1. These are oriented with their outlet openings at an angle of 10° to 45° to the nearest wall section to create a vortex-like mixing effect. Furthermore, four pressure relief valves 2 are routed through the lid, as well as a sampling probe 3, a measuring sensor 4, and an inoculation probe 5. Example 1: Fermentation of press cake from edible oil production as raw material, extrusion of the mycelium with pea protein and pumpkin seed flour as ingredients (not according to the invention)

[0072] As an example of a raw material, rapeseed press cake, a byproduct of rapeseed oil production, was suspended in water at approximately 30% by weight, sterilized by autoclaving at 121°C for 20 minutes, inoculated with mycelium of Flammulina velutipes (velvet shank, enoki), and fermented in a 500 L fermenter under aerobic conditions at 26°C for 8 to 10 days with stirring using a propeller stirrer. The mycelium was separated from the liquid fraction of the resulting fermentation broth by sieving. The mycelium exhibited a similarly compact structure to the pseudotissue of fruiting bodies of the fungus grown on a solid substrate. The mycelium had a water content of approximately 87 to 93%. After mycelium separation, the liquid fraction of the fermentation broth contained no solids larger than 0.1 mm.

[0073] This example shows that in fermentation with basidiomycetes, even cellulose-containing raw materials are completely broken down and converted into fungal mycelium and an aqueous fraction of the fermenter broth.

[0074] The fermentation broth was blended into a composition consisting of 10 wt% fermentation broth including fungal mycelium, 36.7 wt% pea protein isolate, 47.2 wt% fermentation broth, 1.6 wt% pea fiber, 0.7 wt% salt (NaCl), 1.6 wt% yeast flakes, and 2.2 wt% oil (vegetable oil) and immediately fed into a twin-screw extruder. Optionally, the fermentation broth was treated to pulverize the fungal mycelium and then pumped into the composition. The composition generally uses the entire fermentation broth without the addition of water. No water exited the extruder before the extruded mass. Preferably, the mass was cooled to approximately 80°C in a nozzle connected to the extruder outlet, which was optionally a cooling nozzle according to EP 3 621 463 B1.

[0075] In the extruder, the mixture of ingredients reached a maximum temperature of 135 °C.

[0076] The resulting mass, which formed the food product, had a firm consistency, a mild taste, and a light mushroom aroma. No bitter substances, which were present in the original press cake, were detected during sensory testing of the product. Example 2: Fermentation of dried sugar beet pulp as a raw material (not according to the invention)

[0077] As an example of another raw material, dried sugar beet pulp, a byproduct of sugar production, was suspended at approximately 5 wt% in yeast extract solution (0.3 g / L) and pasteurized (75–85 °C for 1 h) to reduce microbial count. The resulting medium (150 mL) was inoculated with mycelium of Pleurotus ostreatus var. florida (oyster mushroom) using 10% (v / v) pre-culture and fermented in a 300 mL shake flask under aerobic conditions at 24 °C for 8 to 14 days with shaking (150 rpm). During cultivation, the cultures were regularly monitored for pH and any microbiological contamination. Sterility testing was performed by streaking on various nutrient media, preparing liquid cultures, and microscopy. The pH value of the fermentation broth increased from pH 4.32 to pH 5.85 during the fermentation period.No microbiological contamination was detected in the fermentation cultures throughout the entire cultivation period. This demonstrated that the reduction of microbial count through pasteurization was sufficient. Furthermore, it was shown that P. sapidus var. florida suppressed the germination of heat-resistant bacterial spores, which cannot be killed by pasteurization, or the subsequent proliferation of the resulting microorganisms, as no microbial contamination could be detected even after reaching a pH value greater than 4.5 (spore germination does not occur below pH 4.5). At the end of the fermentation, a biomass dry weight of 10 to 20 g / L was achieved.

[0078] The mycelium was separated from the liquid fraction of the fermentation broth by sieving or centrifugation. The mycelium exhibited a similarly compact structure to the pseudotissue of fruiting bodies of the fungus grown on a solid substrate. The mycelium had a water content of approximately 89 to 95%. After mycelium removal, the liquid fraction of the fermentation broth contained no solids larger than 0.1 mm.

Claims

[1] Methods for the production of foodstuffs comprising the steps - Pasteurizing a raw material that is a by-product of food production to produce a pasteurized raw material, - Inoculation of the pasteurized raw material with at least one edible basidiomycete and aerobic fermentation of the water-suspended pasteurized raw material in a submerged process to produce a fermenter broth containing mycelium of at least one basidiomycete, - Introducing the entire fermentation broth as an ingredient into an extruder, - Introducing at least one vegetable protein mixture containing vegetable flour selected from protein concentrates, protein isolates or flour made from pumpkin seeds, broad beans, peas, sunflowers or cereals and mixtures of at least two of these, as an ingredient into the extruder, - and extruding the ingredients, whereby the ingredients reach a temperature of at least 65°C, to produce a mass, and before or after the mass exits the extruder, cooling the mass to produce the food. [2] Method according to claim 1, characterized by that the fermentation process takes place for a duration of 5 to 15 days. [3] Method according to any of the preceding claims, characterized by , that the raw material is suspended in water at a rate of 20 to 40 wt% before pasteurization and the resulting suspension is pasteurized. [4] Method according to any of the preceding claims, characterized by , that mycelium of at least one basidiomycete is used for inoculation, which was produced in aerobic submerged fermentation and subsequently crushed by intensive shearing. [5] Method according to any of the preceding claims, characterized bythat aerobic fermentation takes place in an open container, with ventilation using non-sterilised air. [6] Method according to any of the preceding claims, characterized by that in aerobic fermentation, aeration alone causes the mixing. [7] Method according to any of the preceding claims, characterized by that no additional water is added to the ingredients. [8] Method according to any of the preceding claims, characterized by that the ingredients reach a temperature of at least 120°C during extrusion. [9] Method according to any of the preceding claims, characterized by , that no components escape from the mixture during extrusion and cooling of the mass. [10] Method according to any of the preceding claims, characterized by, that the raw material, which is a by-product of food production, is selected from stems of edible mushrooms, cereal and legume straw, sugar beet pulp after sugar extraction, cereal bran, potato peels, apple peels, grape skins, citrus peels and carrot peels, cauliflower trimmings, leek greens, extracted tea leaves, press cake from edible oil production, empty sunflower petals, sunflower skins, nutshells, optionally ground or unground, corn cobs after kernel removal, red peanut shells, brewer's spent grain, wine pomace, optionally after distillation of alcohol, sugar cane bagasse, sugar cane leaves, coffee grounds after extraction, back bread, banana leaves, and mixtures of at least two of these. [11] Method according to any of the preceding claims, characterized by, that the basidiomycete is selected from among Pleurotaceae, in particular Pleurotus ostreatus (oyster mushroom), Pleurotus eryngii (brown oyster mushroom), Pleurotus pulmonarius (chestnut mushroom), Pleurotus citrinopileatus (lemon oyster mushroom), Pleurotus salmoneostramineus (pink oyster mushroom), Omphalotaceae, in particular Lentinus edodes (shiitake), Physalacriaceae, in particular Flammulina velutipes (velvet foot mushroom), Agaricaceae, in particular Macrolepiota procera (parasol mushroom), Agaricus bisporus (button mushroom), Agaricus arvensis (aniseed mushroom), Strophariaceae, in particular Kuehneromyces mutabilis (honey mushroom), Stropharia rugosoannulata (giant or cultivated mist mushroom), Pholiota nameko (golden cap, nameko), Bolbitiaceae, in particular Agrocybe aegerita (Southern Fieldcap), Lyophyllaceae, especially Hypsizygus ulmarius (Elm Mushroom), Hypsizygus tessulatus (Beech Mushroom, Shimeji), Tricholomataceae, especially Lepista nuda (Violet Webcap), Boletaceae,especially Boletus edulis (porcini mushroom), Boletus pinicola, Boletus aereus, Cantharellaceae especially Cantharellus cibarius (chanterelle), Polyporaceae, especially Pleurotus sajor-caju (grey oyster mushroom), Laetiporaceae, especially Laetiporus sulphureus (sulfur polypore), Grifolaceae, especially Grifola frondosa, Auriculariaceae, especially Auricularia auricula-judae, Hericiaceae, especially Hericium erinaceus and combinations of at least two of these. [12] Method according to any of the preceding claims, characterized by , that the extrusion with the steps - Mixing powdered proteins from plant sources and optionally other ingredients to produce a plant protein mixture containing at least 60% by weight plant protein, - Feeding the plant protein mixture into the feed end of an extruder, - Feeding fermentation broth into the extruder through a first feed nozzle of the extruder, which is located downstream of the inlet end of the extruder, wherein the vegetable protein mixture including the fermentation broth contains water to a proportion of 30 wt.% to 60 wt.% of the protein mass exiting the extruder, - optionally, additional ingredients can be added downstream of the inlet end via a second feed nozzle located downstream of the first feed nozzle on the extruder, - wherein the vegetable protein mixture is heated to a temperature of 110 to 150 °C in a section of the extruder and subjected to a pressure of at least 4 bar, - Shaping and cooling the protein mass exiting the extruder. [13] Method according to claim 12, characterized by, that the extruder is cooled in the section upstream of the second feed nozzle in order to cool the mass to a maximum temperature of 125 °C.

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