Methods and equipment for controlling microbial growth in wet plant based biomass material

Abstract

The invention relates to preserving, or increasing the short-term shelf-life of bulk wet plant based or plant derived biomass materials or products susceptible to spoilage due to microbial growth. In particular, the present invention has been developed for the prolonging of the food-grade shelf life of warm wet biomass feedstock such as brewers spent grain to enable the transport from a brewery to downstream processing facility. In one embodiment this could be a renewable electric-powered heater jacket that maintains a specific range of conditions, made from a particular robust insulating composite material. However, it will be appreciated that the invention is not limited to these particular fields of use.

Description

METHODS AND EQUIPMENT FOR CONTROLLING MICROBIAL GROWTH IN WET PLANT BASED BIOMASS MATERIALField

[0001] The present invention, in some embodiments thereof, relates to preserving, or increasing the short-term shelf-life of bulk wet plant based or plant derived biomass materials or products susceptible to spoilage due to microbial growth.

[0002] The invention has been developed for controlling microbial growth in a wet plant based or plant derived biomass material to prolong shelf life of the material. One specific application for which the invention has been developed is preserving brewers spent grain for a sufficient period of time to enable downstream processing. However, the method and system of the invention may also be applied to many other applications where increasing the short-term shelflife of a bulk wet plant based or plant derived biomass materials / products susceptible to spoilage due to microbial growth is required.Background

[0003] Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.

[0004] Over 1.3 billion tonnes of food is wasted globally each year, around 40% of all food produced. This is a major global systemic inefficiency. Much of this is created in farming and processing upstream of the consumer. Food demand is expected to increase over 70% by 2050 due population growth and consumer mega trends.

[0005] A particular problem for the food industry is spoilage of biological food products and particularly wet plant based or plant derived biomass material or products which can be prone to rapid spoilage due to microbial growth. In favourable conditions, microbial growth occurs exponentially and may render a food product unfit for consumption within a few hours.

[0006] Brewers spent grain is a plant based or plant derived biomass food waste that is a byproduct of the brewing industry. Brewers spent grain is obtained as a mostly solid residue after wort production in the brewing process prior to fermentation.

[0007] The majority of brewers spent grain is composed of barley malt grain husks in combination with parts of the germ, pericarp and seed coat layers of the barley. Though the composition of brewers spent grain can vary, depending on the type of grain used, the way it was grown, and other factors, brewers spent grain is usually rich in cellulose, hemicelluloses, lignin, and protein. Since brewers spent grain is widely available wherever beer is produced and is frequently available at a commercially favourable feedstock cost, it is of great interest as a food additive, particularly for replacing lower protein and / or lower-fiber and / or more costly ingredients.

[0008] However, for the most part, the recovery of brewers spent grain for conversion into foodgrade product or other value products is not commercialised. Rather, as seen with reference to FIG. 1, 1001 and 1002, fresh brewers spent grain is typically trucked from the brewer and disposed of as compost or landfill having a detrimental environmental impact including generation of greenhouse gasses, alternatively it may be used as a lower value animal feed. A significant problem of utilising spent grain is the high risk of microbial growth which potentially introduces toxins that cannot be easily removed and renders the product unsuitable for human consumption. Brewers spent grain is discharged from the brewing process as a hot, wet slurry typically at a temperature of 70-80 Celsius with 70-80% moisture content. As the slurry cools, it becomes highly suspectable to microbial proliferation such that after only 4 hours food safety standards declare it is potentially unsafe for use in food grade products.

[0009] This short shelflife, and associated food safety regulatory barriers, make it logistically very difficult to integrate-spent grain feedstock into truck pick-up schedules and day-shift production facilities as part of a food-grade value chain.

[0010] Immediate processing of the spent grain into a more stable product (as illustrated in FIG. 1 1003) is one option however this has inherent limitations. First, in order to reduce or eliminate transportation time it requires specialist machinery processing to be located onsite which is cost and scale prohibitive to all but the largest breweries. These breweries need to have land available to site such a production facility. Furthermore, even where production facilitiescan be collocated, viable processing requires careful scheduling with brewing production and is preferably run as a continuous process which can be difficult to co-ordinate even for large breweries.

[0010] Alternatively, methods for extending the shelflife of the spent grain have been proposed. This would allow greater time to move the spent grain between facilities, reorganization of feedstock batches to optimize finished product profiles and require less urgency between the beer production process and downstream processing.

[0011] One proposed approach is to lower the pH of the spent grain, typically to a pH of 4.6 or lower, such that it is inconducive to problematic microbial growth. This may be achieved by blending a food-grade acid with the spent grain. However, the lower pH of the spent grain may result in food products which are less acceptable to customers. Subsequently neutralising the acidity with an alkaline during processing may result in levels of salts that are also less acceptable.

[0012] Refrigeration (below 4° Celsius) is another commonly considered method for extending shelflife of the brewers spent grain. This may be a practical option for small batch production but is not viable at large production volumes for several reasons. Cooling the grain is comparatively energy inefficient and requires costly and complex cold chain refrigeration systems Furthermore, in bulk amounts, the thermal mass of the spent grain slurry results in slow cooling rates. In addition, refrigeration systems typically need refrigerant gasses that have a significant global warming potential and are inevitably vented into atmosphere at some point in the life-cycle of the refrigeration system, being undesirable from an environmental standpoint.

[0013] It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.Summary of Invention

[0014] In a first aspect, the invention provides a method of controlling microbial growth in a wet plant based biomass material to prolong shelflife of the product, said method including the steps of: receiving the product into a vessel;maintaining the temperature of the wet plant based biomass material within the vessel within a predetermined storage temperature range between a minimum storage temperature and a maximum storage temperature.

[0015] Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”.

[0016] Preferably, the minimum average storage temperature is 63 °C, preferably around 70 °C, or more preferably around 72 °C and, the maximum storage temperature is around 90 °C; preferably around 83 °C, more preferably around 80 °C, or most preferably around 76 °C.

[0017] The wet plant based or plant derived biomass material includes any wet carbohydrate material, product or ingredient, any biomass feedstock or any high fibre feedstock. In one or more embodiments, the wet plant based or plant derived biomass material is a wet carbohydrate material and / or a wet fiber material, such as a high fiber material. In one or more forms, the wet biomass comprises at least 10 wt% carbohydrates. In one or more forms, the wet biomass comprises at least 40 wt% fibre as determined on a dry basis, and preferably at least 45 wt% fibre as determined on a dry basis. More preferably, the fibre is dietary fibre. In various embodiments, the wet biomass material is a tacky material / pomace material / sludge material / slurry material / cake / homogeneous mixture / fibrous material / viscous material.

[0018] In some embodiments, the wet plant based biomass material is brewers spent grain discharged from wort production of a brewing process. In other embodiments the wet plant based biomass material includes one or more of: brewers spent grain, grain, barley, carrot pomace, apple pomace, pear pomace, lemon pomace, orange pomace, tomato pomace, soy okra, fruit matter, and vegetable matter or a juicing pulp by-product (such as apple, pear or citrus fruit press cake), okara (soybean byproduct from the production of soymilk or tofu) or food-grade vegetable processing by-products.

[0019] In preferred embodiments, the wet plant based biomass material is discharged from the wort production at a discharge temperature.

[0020] In preferred embodiments, the storage temperature is ±10°C of the discharge temperature.

[0021] In preferred embodiments, the step of maintaining the temperature of the wet plant based biomass material includes heating the wet plant based biomass material.

[0022] In preferred embodiments, the vessel is heated with a heating element, preferably an electric heating element.

[0023] In preferred embodiments, the heating element is configured to partially surround the vessel.

[0024] In preferred embodiments, the heating element is associated with or incorporated into a removable thermal blanket to at least partially cover the vessel.

[0025] In preferred embodiments, the thermal blanket includes thermal insulation.

[0026] In preferred embodiments, the thermal blanket is formed as a removable thermal insulation jacket covering a top and sides of the vessel.

[0027] In preferred embodiments, the method further includes the step of washing and / or sterilizing the vessel prior to the step of receiving the product.

[0028] In preferred embodiments, the method further includes the step of lining the vessel with a sterilized liner bag prior to the step of receiving the product.

[0029] In preferred embodiments, the vessel is between 200 and 1500 liters capacity.

[0030] In preferred embodiments the container has a base dimension (length x width) about that of a standard Australian pallet (1165mm x 1165mm), or about that of the export standard Australian pallet (1100mm x 1100mm) or about that of the ISO standard pallet (1200mm x 1000mm), or about that of the US standard pallet (48inches x 40 inches).

[0031] In preferred embodiments, wherein the vessel is about the external dimensions of an ISO-Intermediate Bulk Container, preferably a 780 litre Nally MegabBin.

[0032] In preferred embodiments the vessel is made from recycled plastic, bioplastic, fossil-oil based polyethylene (PE), polypropylene (PP) plastic, or stainless steel.

[0033] In preferred embodiments where the vessel is made from a form of plastic, that plastic will have a melting point above 130°C, more preferably above 150°C.

[0034] In preferred embodiments, the vessel includes an openable or removable lid.

[0035] In preferred embodiments, the vessel includes an integrated heating element.

[0036] In preferred embodiments, the heating element is an electrical heating element.

[0037] In preferred embodiments, the vessel includes a control unit electrically connected to the heating element for controlling the heating element.

[0038] In preferred embodiments, the vessel includes a thermostat electrically connected to the heating element and / or a controller for regulating the heating element.

[0039] In preferred embodiments, the vessel includes a sensor to monitor temperature and preferably the sensor is connected to the controller.

[0040] In preferred embodiments, the vessel includes a GPS geographic tracking module.

[0041] In preferred embodiments, the vessel includes a radio transmitting module to transmit data.

[0042] In preferred embodiments, the radio transmitting module utilizes wifi or Bluetooth protocols.

[0043] In a second aspect, the invention provides a method of processing a wet plant based biomass material, said method including: controlling microbial growth in the wet plant based biomass material to prolong shelf life in accordance with the first aspect; processing the wet plant based biomass material within a predetermined shelf-life period said period commencing upon receiving the product into the vessel.

[0044] In preferred embodiments, the step of receiving the product into a vessel is performed at a first location and the step of processing the wet plant based biomass material is performed at a second location.

[0045] In preferred embodiments, the wet plant based biomass material is fully or partially processed at the second location into a food ingredient.

[0046] In a third aspect, the invention provides a removable heating jacket for use with a vessel having a sides and a base wherein said heating jacket is configured for snug fitment over said vessel and comprises: a top panel for covering a top portion of said vessel; side panels for at least partially covering the sides of the vessel; and a heating element supported by at least one of the panels for providing heat to the interior of the vessel.

[0047] In preferred embodiments, the heating element is an electrical heating element.

[0048] In preferred embodiments, the jacket includes a control unit electrically connected to the heating element for controlling the heating element.

[0049] In preferred embodiments, the jacket includes a thermostat electrically connected to the heating element and / or a controller for regulating the heating element.

[0050] In preferred embodiments, the jacket includes a sensor to monitor temperature and preferably the sensor is connected to the controller.

[0051] In preferred embodiments, the jacket includes a GPS geographic tracking module.

[0052] In preferred embodiments, the jacket includes a radio transmitting module to transmit data.

[0053] In preferred embodiments, the radio transmitting module utilizes wifi or Bluetooth protocols.

[0054] In preferred embodiments, the jacket includes an RFID chip to assist with tracking supply chain logistics.

[0055] In preferred embodiments, the vessel includes an RFID chip to assist with tracking supply chain logistics.

[0056] In preferred embodiments, the panels of the jacket comprise an insulation layer.

[0057] In preferred embodiments, the top and side panels of the jacket are flexible.

[0058] In preferred embodiments, the vessel is rectangular and there are four side panels, each side panel corresponding to one of four sides of the vessel.

[0059] In preferred embodiments, the top panel includes a periphery to which each side panel is attached at a respective top edge.

[0060] In preferred embodiments, the jacket includes a base panel for covering a base portion of the base of the vessel and wherein the base panel is attached along a side panel.

[0061] In preferred embodiments, each side panel is connected to adjacent side panels along respective peripheral side edges.

[0062] In preferred embodiments, the jacket includes at least one selectively openable seam to allow for snug fitment and removal of the jacket to the vessel.

[0063] In preferred embodiments, the seam includes hook and loop fastening surfaces for secretively opening / closing the seam.

[0064] In preferred embodiments, the seam includes a zip connector for selectively opening / closing the seam.

[0065] In preferred embodiments, the thermal insulation layer includes one or more of: a waffle material; an encapsulated air pocket material; a cellulose material; a natural fiber material such as a plant based cellulose material or wool fiber material; a fiberglass wadding material; carbon fibre wadding material; a closed cell foam material; a polymer based fiber material such as apolyurethane or polyisocyanurate material, a mineral wool material; a perlite material; a cementitious foam material; a phenolic foam material; a rigid panel fibrous material.

[0066] In preferred embodiments, each panel has a thermal conductivity about 0.034 W / m.k.

[0067] In preferred embodiments, the panel includes a reflective material layer.

[0068] In preferred embodiments, one or more panels comprise an inner layer facing the vessel and an outer layer.

[0069] In preferred embodiments, the panel includes a high temperature resistant Teflon cloth as inner and outer layers.

[0070] In preferred embodiments, the panel includes a protective outer layer.

[0071] In preferred embodiments, the outer layer is water resistant and / or fire resistant.

[0072] In preferred embodiments, the jacket includes an inner antiviral / antimicrobial surface or layer.

[0073] In preferred embodiments, the heating element comprises a heating wire formed of 2080 nickel alloy.

[0074] In preferred embodiments, the heating wire is sewn evenly in a lawnmower pattern onto a fixed Teflon base on the inside face of the insulation wadding, or silicone base material on an inside face of the insulation wadding or the insulation wadding itself.

[0075] In preferred embodiments, each panel includes a layer comprising about 0.4mm Teflon high temperature resistant cloth.

[0076] In preferred embodiments, the panels are rigid or semi rigid.

[0077] In preferred embodiments, the jacket includes a frame for supporting the top panel.

[0078] In preferred embodiments, the jacket includes a hoisting point added to enable hoisting of the jacket over the vessel.

[0079] In preferred embodiments, the jacket includes attachment points in the form of pull / push loops / tie down points.

[0080] In preferred embodiments, the jacket is wired to suit an Australian single phase lOamp, 240v, 50hz electric outlet.

[0081] In alternative embodiments, the jacket is wired to suit an Australian single phase 15amp or 20amp or 25amp or 32amp, 240v, 50hz electric outlet.

[0082] In alternative embodiments, the jacket is wired to suit an Australian three phase electric outlet.

[0083] In preferred embodiments, the jacket is configured for snug fitment to a 780 litre Nally Mega bin.

[0084] In another aspect the invention further provides a removable heating jacket of the third aspect when used in the method of the first or second aspects.Brief Description of Drawings

[0085] The invention will be more clearly understood from the following description of an embodiment thereof, given by way of example only, with reference to the accompanying drawings, in which: -

[0086] Fig. l is a block flow diagram displaying feedstock collection processes of the prior art;

[0087] Fig. 2 is a block flow diagram displaying feedstock collection processes in accordance with the invention;

[0088] Fig. 3 is a photograph of a vessel which may be used in accordance with the invention;

[0089] Fig. 4 is a photograph of the vessel of Fig. 3 including a rigid lid;

[0090] Fig. 5 is a schematic of a removable heating jacket for use with the vessel of Fig. 3 in accordance with the invention;

[0091] Fig. 6 is a photograph of another removable heating j acket for use with the vessel of Fig. 3 in accordance with the invention;

[0092] Fig. 7 is a schematic detail cross section of a portion of the jacket panel in accordance with an embodiment of the invention;

[0093] Fig. 8 is a photograph of the heater jacket shown in Fig. 6 installed on a vessel;

[0094] Fig. 9 is a photograph of a controller for a removable heating j acket in accordance with the invention;

[0095] Fig. 10 is a photograph of another removable heating j acket in accordance with the invention installed on a vessel;

[0096] Fig. 11 is a schematic side and top views of an automatic vessel washing plant;

[0097] Fig. 12 is a photograph displaying brewers spent grain being discharged into a vessel at a brewery during grain out;

[0098] Fig. 13 is a photograph displaying a food-grade bin liner used where food grade cleanliness of the vessel is not guaranteed;

[0099] FIG. 14 shows graphically a temperature log taken at 5-min intervals displaying temperature drop of fresh brewers spent grain in a 780 litre Nally MegaBin stored at room temperature.

[0100] FIG. 15 shows an example of microbial analysis results of brewers spent grain without application of the method of the invention; and

[0100] FIG 16. shows an example of microbial analysis results of brewers spent grain when heated in accordance with the method in accordance with the invention.Description of Embodiments

[0101] In one broad form the invention provides a method of controlling microbial growth in a wet plant based biomass material to prolong shelflife of the product. The method includes thesteps of receiving the product into a vessel which advantageously may be used for storage and transport of the product and maintaining the temperature of the product within the vessel within a predetermined storage temperature range between a minimum storage temperature and a maximum storage temperature.

[0102] The invention will henceforth be described with respect to maintaining food-safe quality, nutritional quality, and desirable sensory traits of brewers spent grain between its discharge from the brewing process and processing into food-grade products. However, it will be appreciated that the invention methods, processes and apparatus of the invention may be used in respect of controlling microbial growth to extend shelflife in other food products and particularly wet-food products.

[0103] Accordingly, the invention also proposes a method of processing brewers spent grain, including, controlling microbial growth in the brewers spent grain to prolong shelf life in accordance with the method recited above and processing the brewers spent grain within a predetermined shelf-life period from receiving the brewers spent grain into the vessel.

[0104] Brewers spent grain is the main by-product of beer production and more specifically wort production. Typically, the spent grain is discharged at 70-80 °C with 70-80% moisture content. The invention involves artificially maintaining the thermal temperature of the spent grain above a predetermined minimum storage temperature selected to be hot enough to prevent or at least reduce the likelihood of microbial growth. The predetermined minimum storage temperature is 63 °C, preferably around 70 °C, or more preferably around 72 °C.

[0105] While increasing the temperature of the grain generally corresponds to reduced microbial growth, increased temperature also may correspond to damage to the brewers spent grains food properties. Accordingly, the maximum storage temperature is selected to minimize damage to the protein or sensory characteristics of the grain. Preferably therefore the maximum storage temperature is around 90 °C; preferably around 83 °C, more preferably around 80 °C, or most preferably around 76 °C.

[0106] Maintaining the temperature of the spent grain within the predetermined temperature range between the predetermined minimum storage temperature and the predetermined maximum storage temperature significantly reduces risk of microbial growth whilst minimizing excessive undesirable degradation of it as a food ingredient. Advantageously, maintaining thefresh brewers spent grain in the preferred temperature range allows the extension of the food safety shelf life of fresh wet brewers spent grain from <4hours to around 48hours or greater before it is further processed.

[0107] As noted, maintaining food-safe quality, nutritional quality, and desirable sensory traits of brewers spent grain between its discharge from the brewing process and processing into foodgrade products has been a key barrier to the commercial development of this value chain. Advantageously, by increasing the shelf life of the spent grain it may be stored for a comparatively longer period of time before spoilage enabling more convenient scheduling with transport logistics and / or downstream production demands.

[0108] Accordingly in some embodiments of the invention, the step of receiving the spent grain into a vessel is performed at a first location and the step of processing the brewers spent grain is performed at a second location. Typically, the spent grain is fully or partially processed at the second location into a food ingredient. The first location is typically the brewery where wort is produced, while the second location is a food production location and remote from the first location.

[0109] Referring to FIG. 2, and process 100, the brewers spent grain is produced as a byproduct of wort production from the lauter tun 101. The brewers grain is typically discharged from the from the lauter tun under gravitational flow and received into a vessel, 102 where it is maintained within a predetermined storage temperature range between a minimum storage temperature and a maximum storage temperature 103. The brewers grain is then transported by ground transport, typically truck 104, 105 to a food processing location where food processing is initiated 106.

[0110] Typically, the vessel has a capacity in the range of between around 200 - 1,500 liters, for instance a 1,000 liter ISO-Intermediate Bulk Containers (IBC). Preferably the vessel is a food grade container and typically is made from polypropylene, or a thermoplastic with a melting point above 150 °C, or more ideally 165 °C or above. In other embodiments the bin made be made from other suitable food grade materials including metals, such as stainless steel.

[0111] Many small to medium breweries use 780 liter vessel commonly referred to as a Nally MegaBin 10 such as shown in FIG. 3, or similar containers. Such bins are consistent with production volumes of small to medium size brewing operations, are large enough to provide asubstantial thermal mass for retaining heat from the production process yet remain small enough to advantageously allow transport by a standard forklift when full of brewers spent grain. IBC and Nally Bins are rectangular typically with a square base 11 and four side walls 12 extending generally vertically from the base to an open top 13. The Nally Megabin base is 1165mm square and it is 780mm high. The base and walls are impervious to liquid and provide a footprint consistent with standardized pallet and shipping infrastructures. The vessel preferably includes a removable hard lid 14 as shown in FIG 4.

[0112] In order to maintain the temperature of the spent grain within a predetermined storage temperature range in one form, the invention provides a thermal jacket for use with the storage vessel. By way of example, a removable electric thermal heater jacket 20 in accordance with the invention is shown in FIG 5. The removable heating j acket 20 shown in FIG 5 is for use with a vessel 10 such as the MegaBin shown in FIGS 3 and 4, having a top, base and sides wherein said heating jacket is configured for snug fitment over said vessel 10. The heating jacket 20 includes a top panel 21 for covering a top face or lid of said vessel 10 and side panels 21, 22, 23, 24 for at least partially covering the side faces of the vessel 20. A heating element (30 - FIG. 6) is supported by at least one of the panels for providing heat to the interior of the vessel.

[0113] In this embodiment the side panels 21, 22, 23, 24 fully cover all the four side faces of the vessel to reduce heat loss and maximise the surface area of the bin exposed to heating. Since the heating jacket shown in FIG 5 is configured to fit the square prism shaped bin of FIG 3 and 4, it further includes a bottom panel 25 to cover under the base of vessel such that the vessel is encapsulated on all six faces. It will be appreciated however, that the jacket should preferably be configured to have a number and size of panels which correspond to the particular shape and dimensions of the vessel used.

[0114] In the embodiment shown, each of the side panels 21, 22, 23, 24 is fixedly attached at a top edge 26 to a respective peripheral edge of the top panel 21 forming flaps thereto. In this embodiment the panels are fixedly sewn along fixed seams with Aramid steel wire (Kevlar) for high strength and high temperature resistance. The bottom panel 25 is fixedly attached to a lower edge 27 of one of the side panels. In some embodiments a continuous piece of fabric material may be used in forming two or more adjacent panels thereby presenting a seamless edge connection 31 as can be seen in FIG. 10.

[0115] The jacket is provided with at least one selectable openable seam for connecting adjacent side panels. In this embodiment each side panel 21, 22, 23, 24 is connected to adjacent side panels along respective peripheral side edges to form a selectively openable seam 28 to allow the jacket to be made to fit snug to the vessel while providing for convenient installation and removal of the jacket to the vessel. Each seam 28 includes hook and loop (Velcro) fastening surfaces 29 for selectively attaching adjacent side panels and conveniently opening / closing the seam 28. In some embodiments the seam / s may be provided with any one or more of an interlocking teeth or zippered closure, or snap locking studs, or button closures, or another type of closure instead of or in addition to the hook and look fastener. In other embodiments an openable seam may be provided through a panel of the jacket.

[0116] Each of the panels may comprise layers as shown in the schematic detail cross section of a portion of the jacket panel of FIG. 6. In this embodiment the jacket panels include an inner facing layer 32 facing the vessel, an outer facing layer 34 and an intermediate layer 36 disposed between the inner and outer layers. The inner and outer layers (32 & 34 respectively) are a 0.4mm Teflon high temperature resistant cloth having a fire resistance rating of A GB8625 and / or a non-combustible rating of DIN4102. In this embodiment the jacket includes an antiviral / antimicrobial surface coating particularly on the inner surface of the inner layer (not shown).

[0117] In other embodiments the jacket is provided with one or more stiff or rigid panels to increase durability and provide for easier fitment. The stiff panels may be connected by flexible portions allowing the panel to fold toward and away from each other allowing the jacket collapse when not in use.

[0118] In some embodiments the jacket could is provided with one or more hoist attachment points so that the jacket may be lifted with hoisting gear from above over the vessel for application and removal and / or cleaning. In other embodiments the jacket includes attachment points in the form of pull / push loops / tie down formations, straps or apertures for securing the jacket to the vessel and or the jacket and vessel for transport.

[0119] In some embodiments the jacket may be extra strengthened on the top so that two or more jacketed vessels can be stacked for storage or transport.

[0120] The intermediate layer 36 is an insulation layer comprising high-silica glass fibre (main chemical composition SiO2 + A1203) wadding insulation capable of over 450 °Cand having a thickness in the range of around 25mm- 100mm and a thermal conductivity rating of around 0.034 W / m.k. Other insulation materials may be used for instance the thermal insulation layer may include one or more of: a waffle material; an encapsulated air pocket material; a cellulose material; a natural fiber material such as a plant based cellulose material or wool fiber material; a fiberglass wadding material; carbon fibre wadding material; a closed cell foam material; a polymer based fiber material such as a polyurethane or polyisocyanurate material, a mineral wool material; a perlite material; a cementitious foam material; a phenolic foam material; a rigid panel fibrous material. In some embodiments the panel includes an additional reflective material layer 38 typically disposed between the intermediate insulation layer 36 and the outer layer 34.

[0121] In this embodiment the heating element 30 is an electrical resistive heating element comprising a 2080 nickel alloy heating wire 31 sewn evenly in a lawnmower pattern onto a fixed fibreglass, teflon or silicone base material 31a on the inside face of the insulation layer 34, providing a fire safe heating element to a maximum temp of 650°C. The heating element is sewn into the four side panels 21, 22, 23, 24 and the base panel of the jacket but not the top panel. Heating the top panel is less effective due to the air gap between the top of the spent grain and the lid of the vessel. In some embodiments the heating element does not extend to the base panel where it may be prone to damage.

[0122] A controller box 42 comprising a programable controller (not shown) is affixed to the outside of the heater j acket. The controller is connected to at least one temperature sensor sensitive to + / - 1 Celsius disposed on the inner layer of the jacket. The heating element is configured to run of standard local supply for instance, in Australia, 2400w, lOamp, 240v, 50hz and a standard Australian 3-pin plug 35. Alternatively, the heating element may be configured to be compatible with higher current draw systems such Australian 3 -phase power allowing up to 3,800watt, 15amp ,100-480v.

[0123] The controller is typically programmed to maintain temperature between of the spent grain in the vessel within the predetermined temperature range. Typically, this is in the vicinity of 70-80°C, with a maximum temperature of 100°C. The controller may be programmable to operate in different modes as required.

[0124] Having confidence that the temperature of the spent grain is maintained during storage and transport is important to the food-grade integrity of the process. In some embodiments the controller monitors and records a log of the temperatures sensed by the sensors. In some embodiments the jacket further includes a radio transmitting module to transmit data operatively connected to the controller. The radio transmitting module utilizes wifi and / or Bluetooth protocols to allow data to be transmitted to and from the jacket.

[0125] Preferably each brewers spent grain container should be monitored and traceable for food safety and quality control. Accordingly, in some embodiments the jacket includes an RFID and / or GPS unit coupled to the controller which may communicate with remote logistics management software to follow the chain-of-custody of the spent grain in order to support a food-safe value chain. Brewers spent grain can vary batch-to-batch in quality, grain bill, treatment and feedstocks. Having a tracible ID assigned to every container allows this to be accurately electronically monitored and controlled, reducing the risk of human error.

[0126] In one embodiment this process may involve loT temperature loggers that may connect to the internet, Bluetooth or directly to a computer for the transfer of temperature / time data. These may be mounted in the containers of the brewer spent grain, on a random or consistent sample basis and either inbuilt or added during filling of the vessel. In versions where they are free floating in the feedstock these may be removed by a geofencing alert notifying automated machinery and / or human operators upon delivery to the bioprocessing facility for robotic, passive, or manual extraction. A metal detector scanning all feedstock coming into a bioprocessing facility will act as a backup - connected with an audio-visual alarm and automated conveyor stopping mechanism this also helps to ensure no metal contaminants, including but not limited to these temperature loggers, can enter downstream processing machinery or final food products.

[0127] In some embodiments the method includes cleaning of the vessel for cleanliness and sterility, needed for food safety prior to receiving the spent grain. Brewers spent grain residues adhere to surfaces of the vessel as they dry and the large amount of residual sugars on the grains surface provides an ideal food source for undesirable microbial activity which must be controlled. The vessel may be manually washed and cleaned, preferably at the brewery immediately prior to receiving the spent grain. However, in other embodiments an automated washing machine 50 may be employed to clean and sterilise the spent grain vessels such as isshown in FIG 10. Preferably the washer would be suitable for the handling and washing of a large number of large food-grade vessels once they are emptied after they have transported brewers spent grain from the brewery to the processing facility. These automated washing machines may operate on a single unit basis or a continuous flow basis.

[0128] The automated washing machine 50 may be located at the brewery or at the bioprocessing facility such that the vessels are cleaned after emptying and prior to the return to the brewery. Preferably the vessel would be visually inspected and sterilised again at the brewery prior to filling. Typically, this final sanitising step would include a surface spray such as Proxitane immediately prior to their use.

[0129] In other embodiments as can be seen in FIG 12 & 13 a liner 52, such as a large polymer bin liner may be used which would reduce the need for sterilization of the vessel. A sterile bin liner is inserted into the vessel 10 immediately prior to receiving the spent grain from the lauter tun 101 and discarded or preferable recycled once the spent grain is removed. The bin liner may be sealed to be airtight to better control contamination risk and reduce heat energy loss. In one embodiment the liner is a large plastic bag that may be sealed shut via manually knot or closure device, such as zip tie, to reduce contamination risk.

[0130] In other embodiments the brewery may use nitrogen or carbon dioxide gas to purge the oxygen from the air-tight brewers spent grain container to create an anaerobic environment that further minimises and slows aerobic microorganism growth that may improve food safety and product quality outcomes.

[0131] While the heater jacket and method of the invention as described above have been developed to integrate seamlessly with existing practices and equipment commonly used in the brewing industry, in another form the method of the invention may incorporate dedicated equipment and processes. For instance in some embodiments the method may utilize storage / transportation vessels in which incorporate the insulation and heating capabilities of the jacket. In such cases the vessel is provided with insulated walls having integrated heating element / s. Furthermore, the process 200 is a variation of the process 100 whereby the step of receiving the brewers grain includes dropping it into a hopper 202 before being transferred 203 into a holding vessel where it is maintained within a predetermined storage temperature range 204. Processing the spent grain may occur onsite or require transport either within the vessel orafter being transferred to a preferably insulated and / or heated tanker truck to offsite processing into a food grade product. Advantageously, in this method, the shelflife of the spent grain is increased allowing the spent grain to be held in a holding vessel either at the first or second location, within the predetermined storage temperature range for a comparatively longer period of time enabling more convenient scheduling with transport logistics and downstream production demands.

[0132] In another embodiment the method in accordance with the invention involves the use of electric battery powered ground transport trucks, recharged via renewable sources of electricity, instead of fossil fuel powered trucks to reduce net emissions from the process. In one embodiment these trucks may be automated and driverless to reduce the cost-pe-tonne-kilometre of transporting the grain. In one embodiment the truck may have an insulated or heated cargo compartment than can contain 7 to 25 tonnes of wet fresh brewers spent grain in large vessels on a single level, two containers wide and stacked one, two or three levels high. The pickup / retrieval route network may be optimised to be most effective and efficient based on factors including the brew schedules of the breweries, feedstock quality’s, traffic (forecast and actual), weather and other factors. These truck routings will be controlled and monitored by software.

[0133] In one embodiment the wet hot brewers spent grain may be mechanically pressed at the brewery prior to transport. This could involve a belt press or screw press. This can reduce the moisture content from the range of 70-85% to 55-70% moisture content, but results in an amount of solubilised protein, vitamin and mineral loss that needs to be considered in the nutritional and economic value of the final food products. Equally the disposal of this press water needs to be considered at the brewery. In most embodiments it is most desirable to maintain this soluble nutritional content, cognisant that this is generally environmentally and economically advantageous but limits the range it is viable for a brewers spent grain feedstock truck-based retrieving network to operate from a central processing facility. In most embodiments it is most ideal to operate one central brewer’s spent grain bioprocessing facility per city metropolitan area on a cooperative basis or similar among all brewers in that catchment area.

[0134] It will be appreciated that the invention proposes a new process for handling of brewers spent grain for subsequent commercial food production. As such there does not currently existstandard food safety protocols or published guidelines for developing this value-chain and foodgrade processing. Instead, a non-standard food safety plan must be developed and proven safe based on a body of evidence. The method advantageously allows for commercially realistic food-safe production of ingredients by extending the shelf life of brewers spent grain. Food safety is considered a number one priority in inventing this method. How brewers spent grain is handled during this step in the process has flow on affects to the overall load of pathogens and heat stable toxins which can accumulate and subsequently impact the technologies processing options and techniques available to be used downstream in the value chain of >to food ingredients >to food products >to human consumption.

[0135] This invention advantageously also provides a device enabling the method for recovering spent grain from breweries for road transport to central processing facilities in Nally MegaBins. This heater jacket design has characteristics that make it affordable to produce, heavy duty, water resistant, fire resistant, easy to use, and fit within the design constraints of virtually all Australian breweries.Appendix

[0136] There is no standard technique or standard regulated requirements for brewers spent grain handling for food handling - Due to its novelty it requires a so-called ‘non-standard’ food safety plan that is developed using a basis of evidence. Typically, the objective is to minimise opportunities for microbial growth in the food-grade biomass. In Australia a food safety plan should have a ‘kill step’ to achieve a 4-5 log reduction in pathogens. This log reduction kills the vast majority of pathogens, but attention still needs to be paid particularly to Bacillus Cerues and S. aureus which can create heat stable toxins, that may cause food poisoning typically diarrheal disease, typically with an onset between 2-8 hours. Minimising opportunities for these pathogens to grow, such maintaining temperatures above the food safety temperature danger zone, particularly above 63 degrees Celsius for at least 30 mins is a good food-safety practice. The methods described herein are typically intended to be integrated with wider processing methods to enable food-grade safety of finished products.

[0137] The graph of FIG. 14 shows an example of 5-min interval temperature log of fresh discharged brewers spent grain in Nally Mega Bin when stored at room temperature. Without insulation or heating the feedstock loses approximately 0.6 degrees Celsius every hour until itreaches equilibrium with the room temperature. Maintaining the brewers spent grain at higher temperature minimises the food safety risk that typically occurs between 4 Celsius and 72 Celsius and most typically between 15 Celsius and 63 Celsius.

[0138] FIG. 15 shows an example of microbial analysis results of brewers spent grain before this method, with limited food safety techniques used. FIG 16. Shows an example of microbial analysis results of brewers spent grain when heated in accordance with the invention. It is noted that the microbial loads are substantially lower in the analysis results when heating is adopted. For example, note the Standard Plate Count before is 290,000 cfu / g but after is only 50 cfu / g. Note this product was dried to ‘freeze time’ for analysis.

[0139] As used herein, the term “about is understood as within a range of normal tolerance in the art, for example within 2 standard deviations of the mean. “About can be understood as within 15%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated value. Unless otherwise clear from context, all numerical values provided herein are modified by the term about.

[0140] Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well- known technologies are not described in detail.

[0142] The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiringtheir performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.

[0143] When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc ). As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items.

[0144] Although the terms first, second, third, etc. may be used herein to describe various elements, compartments, components, regions, layers and / or sections, these elements, components, compartments, regions, layers and / or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

[0145] Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature’s relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0146] Unless specifically stated otherwise, as apparent from the following discussions, it is appreciated that throughout the specification discussions utilizing terms such as “processing,” “computing,” “calculating,” “determining” or the like, refer to the action and / or processes of a microprocessor, controller computer or computing system, or similar electronic computing device, that manipulates and / or transforms data.

[0147] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

[0148] Similarly, it should be appreciated that in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, FIG., or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this invention.

[0149] Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those skilled in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0150] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. Inother instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

Claims

CLAIMS1. A method of controlling microbial growth in a wet plant based biomass material to prolong shelf life of the product, said method including the steps of: receiving the product into a vessel; maintaining the temperature of the wet plant based biomass material within the vessel within a predetermined storage temperature range between a minimum storage temperature and a maximum storage temperature.

2. The method of claim 1 wherein the minimum storage temperature is 63 °C, preferably around 70 °C, or more preferably around 72 °C.

3. The method of claim 1 or 2 wherein the maximum storage temperature is around 90 °C; preferably around 83 °C, more preferably around 80 °C, or most preferably around 76 °C.

4. The method of any one of the preceding claims wherein the wet plant based biomass material is brewers spent grain discharged from wort production.

5. The method of any one of the preceding claims wherein the wort production is part of a brewing production cycle.

6. The method of claim 4 or 5 wherein the brewers spent grain is discharged from the wort production at a discharge temperature.

7. The method of claim 6 wherein the storage temperature is ±10°C of the discharge temperature.

8. The method of any one of claims 1 - 3 wherein the wet plant based biomass material includes one or more of: juicing pulp by-product (such as apple, pear or citrus fruit press cake), okara (soybean byproduct from the production of soymilk or tofu) or food-grade vegetable processing by-products.

9. The method of any one of the preceding claims wherein the step of maintaining the temperature of the wet plant based biomass material includes heating the wet plant based biomass material.

10. The method of claim 9 wherein the vessel is heated with a heating element, preferably an electric heating element.

11. The method of claim 10 wherein the heating element is configured to partially surround the vessel.

12. The method of claim 10 or 11 wherein the heating element is associated with or incorporated into a removable thermal blanket to at least partially cover the vessel.

13. The method of claim 12 wherein the thermal blanket includes thermal insulation.

14. The method of claim 13 wherein the thermal blanket is formed as a removable thermal insulation jacket covering a top, and sides and preferably base of the vessel.

15. The method of any one of the preceding claims including the step of washing and / or sterilizing the vessel prior to the step of receiving the product.

16. The method of any one of the preceding claims including the step of lining the vessel with a sterilized liner bag prior to the step of receiving the product.

17. The method of any one of the preceding claims wherein the vessel is between 200 and 1500 liters capacity.

18. The method of any one of the preceding claims wherein the vessel is an ISO-Intermediate Bulk Container preferably a 7801itre Megabin.

19. The method of any one of the preceding claims wherein the vessel includes an openable lid.

20. The method of any one of the preceding claims wherein the vessel includes an integrated heating element21. The method of any one of the preceding claims wherein the heating element is an electrical heating element.

22. A method of processing a wet plant based biomass material, said method including: controlling microbial growth in the wet plant based biomass material to prolong shelflife in accordance with the method of claims 1 to 20; processing the wet plant based biomass material within a predetermined shelf-life period said period commencing upon receiving the product into the vessel.

23. The method of claim 21 wherein the step of receiving the product into a vessel is performed at a first location and the step of processing the wet plant based biomass material is performed at a second location.

24. The method of claim 22 wherein the wet plant based biomass material is fully or partially processed at the second location into a food ingredient.

25. A removable heating j acket for use with a vessel having a sides and a base wherein said heating jacket is configured for snug fitment over said vessel and comprises: a top panel for covering a top portion of said vessel; side panels for at least partially covering the sides of the vessel; and a heating element supported by one of the panels for providing heat to the interior of the vessel.

26. The removable heating j acket of claim 25 wherein the heating element is an electrical heating element.

27. The removable heating j acket of claim 25 including a control unit electrically connected to the heating element for controlling the heating element.

28. The removable heating j acket of claim 25 including a thermostat electrically connected to the heating element and / or a controller for regulating the heating element.

29. The removable heating j acket of claim 27 wherein the j acket includes a sensor to monitor temperature and preferably the sensor is connected to the controller.

30. The removable heating jacket of claim 25 wherein the jacket includes a GPS module.

31. The removable heating j acket of claim 25 wherein the j acket includes a radio transmitting module to transmit data.

32. The removable heating j acket of claim 25 wherein the radio transmitting module utilizes wifi or Bluetooth protocols.

33. The removable heating j acket of claim 25 wherein the j acket includes a RFID chip to assist with tracking supply chain logistics.

34. The removable heating j acket of claim 25 wherein the panels comprise an insulation layer.

35. The removable heating jacket of claim 25 wherein the top and side panels are flexible.

36. The removable heating jacket of claim 25 wherein the vessel is rectangular and there are four side panels, each side panel corresponding to one of four sides of the vessel.

37. The removable heating j acket of claim 25 wherein the top panel includes a periphery to which each side panel is attached at a respective top edge.

38. The removable heating j acket of claim 25 further including a base panel for covering a base portion of the base of the vessel and wherein the base panel is attached to a side panel along a distal side.

39. The removable heating j acket of claim 25 wherein each side panel is connected to adjacent side panels along respective peripheral side edges.

40. The removable heating jacket of claim 25 wherein including at least one selectively openable seam to allow for snug fitment and removal of the jacket to the vessel.

41. The removable heating j acket of claim 39 wherein the seam includes hook and loop fastening surfaces for secretively opening / closing the seam.

42. The removable heating j acket of claim 39 wherein the seam includes a zip connector for selectively opening / closing the seam.

43. The removable heating j acket of claim 25 wherein the thermal insulation layer includes one or more of: a waffle material; an encapsulated air pocket material; a cellulose material; a natural fiber material such as a plant based cellulose material or wool fiber material; a fiberglass wadding material; carbon fibre wadding material; a closed cell foam material; a polymer based fiber material such as a polyurethane or polyisocyanurate material, a mineral wool material; a perlite material; a cementitious foam material; a phenolic foam material; a rigid panel fibrous material.

44. The removable heating j acket of claim 25 wherein each panel has a thermal conductivity 0.034 W / m.k.

45. The removable heating j acket of claim 25 wherein the panel includes a reflective material layer.

46. The removable heating jacket of claim 25 wherein one or more panels comprise an inner layer facing the vessel and an outer layer.

47. The removable heating j acket of claim 25 wherein the panel includes a high temperature resistant teflon cloth as inner and outer layers.

48. The removable heating jacket of claim 25 wherein the panel includes a protective outer layer.

49. The removable heating j acket of claim 25 wherein the outer layer is water resistant and / or fire resistant.

50. The removable heating j acket of claim 25 wherein the j acket includes an inner antiviral / antimicrobial surface or layer.

51. The removable heating j acket of claim 25 wherein the heating element comprises a heating wire formed of 2080 nickel alloy.

52. The removable heating j acket of claim 50 wherein the heating wire is sewn evenly in a lawnmower pattern onto a fixed fibreglass, teflon or silicone base material on an inside face of the insulation wadding.

53. The removable heating j acket of claim 25 wherein each panel includes a layer comprising 0.4mm Teflon high temperature resistant cloth.

54. The removable heating jacket of claim 25 wherein the panels are rigid or semi rigid.

55. The removable heating j acket of claim 25 including a frame for supporting the top panel.

56. The removable heating j acket of claim 25 wherein the jacket includes a hoisting point added to enable hoisting of the jacket over the vessel.

57. The removable heating j acket of claim 25 wherein the j acket includes attachment points in the form of pull / push loops / tie down points.

58. The removable heating j acket of claim 25 wherein the jacket is wired to suit an Australia lOamp, 240v, 50hz electric outlet.

59. The removable heating jacket of claim 25 wherein the jacket is configured for snug fitment to a 780 litre Nally Mega bin.

60. The removable heating j acket of any one of claims 25 to 58 when used in the method of any one of claims 1 to 24.

Images