DK177482B1

DK177482B1 - Method of manufacturing a fermented dry feed using a spin flash dryer

Info

Publication number: DK177482B1
Application number: DKPA201170489A
Authority: DK
Inventors: Jens Hoeffner Legarth
Original assignee: Fermentationexperts As
Priority date: 2011-09-02
Filing date: 2011-09-02
Publication date: 2013-07-08
Also published as: WO2013029632A1; DK201170489A

Abstract

The present invention pertains to a method for producing a dry fermented feed product comprising the step of providing a fermented feed product, wherein said feed product comprises Iactic acid bacteria, introducing said feed product of into a dryer chamber, contacting said feed product with a stream of drying gas in said dryer chamber, and obtaining a dry fermented feed product. Moreover the present invention pertains to the dry fermented feed product obtainable by the method of the present invention.

Description

i DK 177482 B1

Method of manufacturing a fermented dry feed using a spin flash dryer Technical field of the invention

The present invention relates to a method for producing a dry fermented feed 5 product. In particular, an improved method for producing a dry fermented feed product comprising high levels of viable lactic acid producing bacteria.

Background of the invention

There is a demand in the art for dry fermented feed products having low spoilage 10 (i.e. low levels of pathogenic microorganisms) and improved nutritional value.

Fungi are the principal cause of spoilage of livestock feed, particularly in feed comprising legumes. Some fungal species may cause serious disease in livestock consuming the feed by elaborating toxins. Bacterial spoilage may also occur 15 although the problem is in particular in liquid feed.

Potential harmful bacteria and organisms are natural inhabitants of soil and vegetation and are accordingly found on feed components and everywhere in the animal's surroundings. The bacteria and other organisms present will ferment, 20 unless prevented e.g. by sterilisation. The fermentation may result in outgrow of pathogenic bacteria or various types of yeast and moulds.

Providing fermented feed products prepared to contain low levels of pathogenic microorganisms and high levels of probiotic bacteria to growing pigs have been 25 reported to decrease pathogenic microorganisms counts along the gastrointestinal tract.

Fermented feed comprising probiotic bacteria in the form of lactic acid producing bacteria is often delivered to the animals in the form of liquid feed using liquid 30 feeding system. However, it may be preferred to deliver the feed as dry feed for various reasons, e.g. certain animals are not able to consume liquid feed.

2 DK 177482 B1

Methods for manufacturing dry fermented feed usually involve the use of conventional dryer to remove the moisture of a (semi)liquid feed to obtain a dry feed. Conventional dryer, such as toasters, operate at very high temperature thus, severely impair the viability of the probiotic bacteria in the feed.

5 WO 97/19307 (APV Anhydro A/S) discloses a process and an apparatus for drying a material in the form of a paste or a filter cake in a spin flash dryer. The products dried according to WO 97/19307 are fruit and beet pulps, destillere residues, pesticides, pigments, dyes, ceramics, active coal, sludge and zeolites. WO 10 97/19307 is hereby incorporated by reference.

Hence, an improved method for producing a dry fermented feed low in pathogenic microorganisms and having improved nutritional value would be advantageous, and in particular having a high level of probiotic bacteria would be advantageous.

15

Summary of the invention

An object of the present invention relates to the provision of an improved method of manufacturing a dry fermented feed product.

20 In particular, it is an object of the present invention to provide an improved method for the production of a dry fermented feed comprising a high level of viable lactic acid bacteria (i.e. probiotic bacteria).

The present inventors have surprisingly discovered that the method of the present 25 invention allows for the provision of a dry fermented feed which simultaneously comprise low levels of pathogenic microorganisms and high levels of viable lactic acid bacteria (LAB). Using traditional drying techniques, such a toasting, the viability of lactic acid bacteria is significantly decreased (if not completely obliterated) during the process of producing dry fermented feed products -30 however, the inventor surprisingly discovered a gentle drying process, wherein the viability of the lactic acid bacteria in the fermented feed (to be dehydrated) is maintained or only slightly decreased.

3 DK 177482 B1

Thus, the present invention relates to a method for producing a dry fermented feed product comprising the step of (a) providing a fermented feed product, wherein said feed product comprises lactic acid bacteria, (b) introducing said feed product of (a) into a dryer chamber of a spin flash dryer, 5 (c) contacting said feed product of (a) with a stream of drying gas in said dryer chamber, and (d) obtaining a dry fermented feed product.

Detailed description of the invention 10 Definitions

Prior to discussing the present invention in further details, the following terms and conventions will first be defined:

Inoculum 15 Inoculation refers the placement of a microorganism(s) (e.g. lactic acid bacteria) that will grow when implanted in a culture medium. Inoculum refers to the material used in an inoculation, for example a composition comprising a living organism(s), which is employed to prime a process of interest. For example, an inoculum, where the bacteria are essentially lactic acid bacteria, may be used to 20 direct a lactic acid formation process in a culture medium in a fermentation tank comprising said media (e.g. a feed material). Thus, to "to inoculate" refers to the transfer of the inoculum to the media to be processed, for example the transfer of the inoculums to a feed material to be fermented. The primary inoculum refers to the generation of the initial inoculum in a repeated series essentially identical 25 inoculation process, for example one or more repetitions of a fermentation process. An aliquot of the product of the formation process may be used to inoculate a new process of fermentation. Thus, the inoculation may be a fermented feed product which comprises viable lactic acid bacteria in sufficient amount to prime a lactic acid fermentation process of a another feed product to 30 be fermented. The inoculum may be a in a liquid form, dry form, or essentially dry form. The moisture% of the inoculum may be adjusted in order to optimize the fermentation process. Thus, the inoculum used in the method of the present invention may be a fermented feed product. In one embodiment the inoculum is provided as essentially pure viable bacteria (such as bacteria in freeze dried form) 4 DK 177482 B1 or bacteria suspended in a suitable media prior to the application (such as a water, buffer or a growth media).

The proportion of the inoculums added to the feed product may vary. In case it is 5 considered that the load of undesirable microbes are significant in the feed product or the fermentation system, the proportion of the inoculum in the fermentation mixture (inolucum + feed product + additional water) may be increased to insure that the fermentation is directed by the microbes (e.g. lactic acid bacteria) of the inoculums.

10

Lactic acid bacteria

The class of lactic acid bacteria (or lactic acid producing bacteria) comprise a clade of Gram positive, low-GC, acid tolerant, non-sporulating, non-respiring rod or cocci that are associated by their common metabolic and physiological 15 characteristics. These bacteria, usually found in decomposing plants and lactic products produce lactic acid as the major metabolic end product of carbohydrate fermentation. This trait has historically linked lactic acid bacteria with food fermentations as acidification inhibits the growth of spoilage agents.

Proteinaceous bacteriocins are produced by several lactic acid bacteria strains and 20 provide an additional hurdle for spoilage and pathogenic microorganisms. Furthermore, lactic acid and other metabolic products contribute to the organoleptic and textural profile of a food item. The industrial importance of the lactic acid bacteria is further evidenced by their generally regarded as safe (GRAS) status, due to their ubiquitous appearance in food and their contribution 25 to the healthy microflora of animal mucosal surfaces.

Lactic acid fermentation

Lactic acid fermentation is the simplest type of fermentation. Essentially, it is a redox reaction. In anaerobic conditions, the cell's primary mechanism of ATP 30 production is glycolysis. Glycolysis reduces - transfers electrons to - NAD+, forming NADH. However, there is only a limited supply of NAD+ available in a cell. For glycolysis to continue, NADH must be oxidized - have electrons taken away -to regenerate the NAD+. This is usually done through an electron transport chain 5 DK 177482 B1 in a process called oxidative phosphorylation; however, this mechanism is not available without oxygen.

Instead, the NADH donates its extra electrons to the pyruvate molecules formed 5 during glycolysis. Since the NADH has lost electrons, NAD+ regenerates and is again available for glycolysis. Lactic acid, for which this process is named, is formed by the reduction of pyruvate.

In heterolactic acid fermentation, one molecule of pyruvate is converted to 10 lactate; the other is converted to ethanol and carbon dioxide. In homolactic acid fermentation, both molecules of pyruvate are converted to lactate. Homolactic acid fermentation is unique because it is one of the only respiration processes to not produce a gas as a byproduct.

15 Homolactic fermentation breaks down the pyruvate into lactate. It occurs in the muscles of animals when they need energy faster than the blood can supply oxygen. It also occurs in some kinds of bacteria (such as lactobacilli) and some fungi. It is this type of bacteria that converts lactose into lactic acid in yogurt, giving it its sour taste. These lactic acid bacteria can be classed as 20 homofermentative, where the end product is mostly lactate, or heterofermentative, where some lactate is further metabolized and results in carbon dioxide, acetate or other metabolic products.

The process of lactic acid fermentation using glucose is summarized below. In 25 homolactic fermentation, one molecule of glucose is converted to two molecules of lactic acid: C6H1206 -+ 2 CH3CHOHCOOH.

In heterolactic fermentation, the reaction proceeds as follows, with one molecule 30 of glucose being converted to one molecule of lactic acid, one molecule of ethanol, and one molecule of carbon dioxide: C6H1206 -+ CH3CHOHCOOH + C2H50H + C02

Before lactic acid fermentation can occur, the molecule of glucose must be split 35 into two molecules of pyruvate. This process is called glycolysis.

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It is preferred that the dry fermented feed of present invention is obtained by lactic acid fermentation. It is also preferred that the fermentation is homolactic fermentation directed by homofermentative lactic acid bacteria.

Feed material

The term "feed material" according to the invention is to be understood in its broadest sense. "Feed material" may suitably be obtained from the dairy industry, food processing industry, the agricultural industry, the wine industry, the alcohol 10 industry, or beer industry, or combinations thereof. Examples of suitable "feed material" comprise one or more of mature and/or immature plants and parts thereof, such cereals, e.g. wheat, barley, rye, rice, maize (cob maize silage (CCM) or ripe), triticale, oat; vegetables (e.g. potatoes, maize, soy; whey, curd, skim milk and the like). The feed to be fermented may also consist essentially of a 15 composition of one or more of proteinaceous plant materials. The feed material to be fermented may include animal products such as industrial animal by-products such as blood meal and bone meal. Another non-limiting example of a useful animal product is mussels.

20 The terms "fermented product" or "fermented feed" indicate any product or feed that has been fermented.

In the context of the present invention the terms "dry fermented product" or "dry fermented feed product" refers to a dry product or dry feed product obtained by 25 reducing the moisture content of a fermented product or fermented feed product to obtain a dry fermented feed product.

Bacterial viability

Bacterial viability is to be understood as is the ability of bacteria to survive, grow, 30 and multiply. Bacterial viability can be measured using any known method in the art such as but not limited to (i) measurement of colony forming units (CFU), (ii) staining using e.g. probes for membrane integrity or physiological state and (iii) amplification techniques such as PCR and RT-PCR.

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Per cent Moisture (% moisture, or % H20)

Per cent Moisture refers to the proportion of water in the material (e.g. in the feed). Volumetric water content, Θ (or vol-%), is defined mathematically as: Θ = 5 Vw/ VT, where Vw is the volume of water and VT = Vs + Vv = Vs + Vw + Va is the total volume (that is material Volume + Water Volume + Void Space). Water content may also be based on its mass or weight (w/w%), thus the gravimetric water content is defined as: u = mw/mb, where mw is the mass of water and mb (or ms for soil) is the bulk material mass. To convert gravimetric water content to 10 volumetric water, multiply the gravimetric water content by the bulk specific gravity of the material.

Method for producing a dry fermented feed product

The present invention relates to a method for producing a dry fermented feed 15 product, comprising the steps of: (a) providing a fermented feed product, wherein said feed product comprises lactic acid bacteria; (b) introducing said feed product of (a) into a dryer chamber of a spin flash dryer; (c) contacting said feed product of (a) with a stream of drying gas in said dryer 20 chamber, and (d) obtaining a dry fermented feed product.

In one embodiment, the method comprises the steps of: (a) providing a fermented feed product, wherein said feed product comprises 25 lactic acid bacteria by (i) providing an inoculum comprising bacteria, (ii) providing a feed material; (iii) combining the materials of steps (i), (i) and fermenting the feed material of step (ii) using the inoculum of step (i) to obtain said fermented 30 feed product; (b) introducing said fermented feed product of (a) into a dryer chamber of a spin flash dryer; (c) contacting said fermented feed product of (a) with a stream of drying gas in said dryer chamber, and 8 DK 177482 B1 (d) obtaining a dry fermented feed product.

The moisture content of the product obtained in step (d) can be controlled by adjusting the amount of fermented feed product feed to said dryer chamber in 5 step (b) and/or adjusting the drying capacity of said drying gas.

In order to obtain sufficient dehydration of the fermented feed product provided in step (a) it may be preferred that the moisture content of the excess drying gas is 0.4 kg moisture per kilogram dry gas or higher.

10

Thus, typically the moisture is evaporated at a rate in the range of 600 to 900 kg moisture per hour.

In an embodiment the flow rate of which the drying gas flows through the drying 15 chamber is in the range of 30000 to 40000 m3 drying gas per hour.

The term drying gas is to be understood in its broadest context, thus the term covers any gas including air applicable for drying. From a financial point of view it may be preferred that the drying gas is air. In a preferred embodiment the drying 20 gas it hot air. Air is mainly composed of nitrogen, oxygen, and argon, which together constitute the major gases of the atmosphere.

Thus, preferably the inlet temperature of the drying gas is in the range of 120 to 160 °C.

25

Clearly, it is important to use an inlet temperature of the drying gas which simultaneously (i) provides a sufficient dehydration of the fermented feed product provided in step (a) and (ii) retain viable lactic acid bacteria in the dry fermented feed product obtained in step (d).

30

As the inlet temperature of the drying gas affect the temperature of the dry fermented feed product obtained in step (d) it may be preferred that the temperature of the product obtained in step (d) is the range of or do not exceed 40 to 75°C, preferably measured at the out let of the drying chamber.

35 9 DK 177482 B1

It may also be preferred that the temperature of the product obtained in step (d) is the range of or do not exceed 40 to 60 °C, preferably measured at the outlet of the drying chamber.

5 Traditionally, the drying chamber of a spin flash dryer has been used for drying fruit and beet pulps, destillers residues, pesticides, pigments, dyes, ceramics, active coal, sludge and zeolites. The present inventors surprisingly discovered that such drying chamber can be used for in a process of dehydrating fermented feed comprising probiotic bacteria as provided with present invention - i.e. a process 10 wherein the viability of the lactic acid bacteria in the dry fermented feed product is maintained or only slightly decreased when compared to the fermented feed product from which it is derived.

When operating a spin flash dryer, the drying gas create a high velocity, whirling 15 a fluidised bed of drying particles which moves up through the chamber during the during process. Heavy, still wet lumps are forced towards the chamber walls. Disintegration, attrition and drying cause particles to become smaller and lighter and, as a consequence, a balances fluid bed is created in which smaller particles move towards the axis of the drying chamber.

20

By selecting operating conditions, a state of equilibrium is obtained in which the feed rate of moist is in balance with the corresponding drying capacity (a principle, known to the skilled person in the art of drying) and with the discharge rate of the dries product. It is a special effect of the spin flash dryer that the 25 particles remain in the drying zone until they obtain the desired size.

In order to prevent spoilage of the dry fermented feed product it is important that the moisture content is kept low. Thus, in a preferred embodiment the moisture content of the dry fermented feed product obtained in step (d) is in the range of 5 30 to 15 w/w%.

The drying efficiency is affected by the consistency of the fermented feed provided in step (a). Thus, it is preferred that such fermented feed is either liquid or semisolid (such as a paste or a filter cake). Thus, in one embodiment the moisture content of the feed provided in step (a) is in the range of 25 to 95 w/w%.

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Lactic acid bacteria

It follows that the lactic acid bacteria provided with the fermented feed of step (a) is essentially or for the major part viable since the object is to provide a dry feed comprising high amount of viable (probiotic) lactic acid bacteria. As previously 5 mentioned the inventor surprisingly found that high levels of viable lactic acid bacteria present in the fermented feed provided in step (a) can be retained in the dry fermented feed product obtained in step (d) by use the method of the present invention. Lactic acid bacteria are probiotic organisms - i.e. organisms which when administered in adequate amounts confer a health benefit on the host (i.e.

10 the animal consuming them). Thus, using a dry fermented feed product comprising high levels of viable lactic acid bacteria may provide significant benefits in terms of improved health and improved growth of the animals consuming them. Clearly, the nutritional value of the dry fermented feed product maintained and the probiotic property of the feed is improved when compared to 15 traditionally produced dry fermented feed products, such a dry feed obtained by toasting of a fermented (semi)liquid feed.

All types of lactic acid bacteria may be present in the in the fermented feed provided in step (a). Hence, the lactic acid bacteria comprises at least one 20 bacteria genus selected from the list consisting of Enterococcus, Lactobacillus, Pediococcus and Lactococcus.

The lactic acid bacteria may comprise at least one species selected from the list consisting of Enterococcus spp., Lactobacillus spp., Lactococcus spp., and 25 Pediococcus spp..

In the method according to the inventionthe lactic acid bacteria may comprise at least one species selected from the list consisting of Enterococcus faecium, Lactobacillus rhamnosus, Lactobacillus plantarum, Pediococcus acidiHlactiH, and 30 Pediococcus pentosaceus.

The inventor surprisingly discovered that a dry fermented feed comprising viable lactic acid producing bacteria may be obtained by briefly exposing the feed to a hot drying gas in a spin flash dryer. Although the bacteria are exposed to drying 11 DK 177482 B1 gas having a high temperature, the viability of the bacteria are less affected than by conventional drying processes such as toasting (See Example 1).

By using the method of the present invention 60 to 100% of the viable lactic acid 5 bacteria present in the fermented feed provided in step (a) may be retained in the dry fermented feed product obtained in step (d).

The fermented feed product

Probiotics such as lactic acid bacteria are commonly consumed as part of 10 fermented feed - thus, the fermented feed product provided in step (a) may be obtained essentially by homo-fermentative fermentation.

"Essentially homofermentative" means, that the predominant bacterial flora driving the fermentation is homofermentative. 99% or more of the bacteria may 15 be homofermentative. Alternatively, 95% or more of the bacteria, 90% or more of the bacteria, 80% or more of the bacteria or, 70% or more of the bacteria are homofermentative. "Essentially homofermentative" indicates also that the major fermentation product is lactic acid, and the levels of acetic acid and ethanol are either below taste threshold, around taste threshold or slightly above taste 20 threshold. Alternatively, "essentially homofermentative" indicates a ratio of lactic acid to acetic acid or lactic acid to ethanol (mM/mM) of 7:1 or 10:1 or more, 20:1 or more, 50:1 or more, or 100:1 or more. The ratio of lactic acid to acetic acid or lactic acid to ethanol (mM/mM) may also be 1:1.

25 The fermented feed product in step (a) may also be obtained essentially by hetero-fermentative fermentation.

"Essentially heterofermentative" means, that the predominant bacterial flora driving the fermentation is heterofermentative. 99% or more of the bacteria, such 30 as 95% or more, 90% or more, 80% or more, or 70% or more of the bacteria are heterofermentative. "Essentially heterofermentative" indicates also that the major fermentation product is acetic acid, and the levels of lactic acid are either below taste threshold, around taste threshold or slightly above taste threshold. Alternatively, "essentially heterofermentative" indicates a ratio of acetic acid to 35 lactic acid (mM/mM) of 7:1 or 10:1 or more, 20:1 or more, 50:1 or more, or 12 DK 177482 B1 100:1 or more. The ratio of lactic acid to acetic acid or lactic acid to ethanol (mM/mM) may also be 1:1.

As mentioned previously the difference between homo- and heterofermentation is 5 essentially the class of bacteria performing the fermentation.

These lactic acid bacteria can be classed as homofernrientative, where the end product is mostly lactate, or heterofermentative, where some lactate is further metabolized and results in carbon dioxide, acetate or other metabolic products.

10

In order to prevent spoilage of the fermented feed product provided in step (a) it may be preferred that the fermented feed product provided in step (a) has a pH between 3.5 and 5, such as between 3.6 and 4.9, e.g. between 3.7 and 4.8, such as between 3.8 and 4.7, e.g. between 3.9 and 4.6, such as between 4.0 and 4.5, 15 e.g. between 4.1 and 4.4, such as between 4.2 and 4.3, e.g. between 3.7 and 3.9. In particular, the pH is around 3.8.

Besides from preventing spoilage the acidic components produced also contribute to the organoleptic and textural profile of the fermented feed product provided in 20 step (a) thus, also affecting the organoleptic and textural profile of the dry fermented feed product obtained in step (d).

Lactic acid bacteria produce lactic acid during fermentation of a fermentable carbon source, which results in acidification of the environment. Depending on the 25 starter culture or starter cultures used, as well as on the availability of fermentable sugar(s), thus the lactic acid concentration of the fermented feed product in step (a) may vary.

Thus, if the fermented feed product provided in step (a) has been obtained 30 essentially by homo-fermentative fermentation, it may be preferred that the fermented feed product provided in step (a) has an lactic acid concentration in the range of 50-100 mM, such as 100-150 mM, e.g. 150-200 mM, such as 200-250 mM, e.g. 250-300 mM, or 300 mM or more.

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If the fermented feed product provided in step (a) has been obtained essentially by hetero-fermentative fermentation, it may be preferred that the fermented feed product provided in step (a) has an acetic concentration in the range of 50-100 mM, such as 100-150 mM, e.g. 150-200 mM, such as 200-250 mM, e.g. 250-300 5 mM, or 300 mM or more.

The fermentation should be continued until reaching a desired pH thus, fermentation may be continued up to 6 weeks, such as 4 weeks, such as 3 weeks, such as 2 weeks, e.g. 1 week. In particular,the fermentation product provided in 10 step (a) has been fermented for 12-24 hours, e.g. 8-12 hours, such as 6-8 hours, e.g. 4-6 hours, or less than 4 hours.

The fermented feed product provided in step (a) may have been fermented at a temperature between 10-50°C, 15-40°C, 18-30°C, 20-25°C, or 22-24°C or 15 around 23°C.

In an embodiment of the present invention the fermented feed provided in step (a) is obtained by fermenting one or more industrial products. Such industrial products may be by-product such as one or more of whey, curd, spent grain, 20 yeast, fungus, bacteria, plants or parts thereof, potato or parts thereof.

The fermented feed provided in step (a) may sometimes comprise one or more of ripe or unripe plants or parts thereof. Accordingly, the fermented feed provided in step (a) comprises one or more of barley, wheat, rye, oat, maize, rice, beans, 25 peas, sorghum, triticale, soy, rape or other proteinous plant material. If the plant is maize the fermented feed provided in step (a) may thus, comprise grain maize and corn cob mix (CCM maize).

Inoculum 30 The pH of the inoculum may be between 3.5 and 5, such as between 3.6 and 4.9, e.g. between 3.7 and 4.8, such as between 3.8 and 4.7, e.g. between 3.9 and 4.6, such as between 4.0 and 4.5, e.g. between 4.1 and 4.4, such as between 4.2 and 4.3, e.g. between 3.7 and 3.9.

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The lactic acid concentration in the inoculum for the fermentation in step (a) can be higher than the lactic acid concentration in the fermented feed obtained in step (a).

5 The lactic acid concentration in the inoculum for the fermentation in step (a) can be higher than the lactic acid concentration in the fermented feed obtained by the fermentation in step (a). In another embodiment of the invention, the lactic acid concentration in the fermented feed obtained by the fermentation in step (a) is higher than in the inoculum. Alternatively, the lactic acid concentrations of 10 inoculum and fermented product are approximately the same.

Preferably the inoculum is obtained essentially by homo-fermentative or hetero-fermentative fermentation - thus, the fermentation is driven and controlled by lactic acid bacteria as the most predominant fermentative organisms.

15

The inoculum used for the fermentation of the feed material preferably comprises lactic acid producing bacteria. Accordingly, said inoculum preferably comprises lactic acid bacteria.

20 The inoculum may comprise lactic acid bacteria selected from the group consisting of one or more of Enterococcus spp., Lactobacillus spp., Lactococcus spp., and Pediococcus spp..

Also,the inoculum may have been obtained by fermentation with an inoculum 25 comprising lactic acid bacteria selected from the group consisting of one or more of Enterococcus spp., Lactobacillus spp., Lactococcus spp., and Pediococcus spp..

The inoculum s may also have been obtained by fermentation with an inoculum comprising lactic acid bacteria selected from the group consisting of one or more 30 of Enterococcus faecium, Lactobacillus rhamnosus, Lactobacillus plantarum, Pediococcus acidililactili, and Pediococcus pentosaceus.

Most yeasts and moulds are indeed able to grow under very acetic conditions, however, it has been recognised that quick and efficient production of lactic acid 35 by the lactic acid-producing bacteria cause very reduced or even eliminated 15 DK 177482 B1 growth of such yeasts and moulds. It follows that the inoculum preferably comprises lactic acid-producing bacteria in sufficient amount to control the fermentation process in order to obtain a feed, which is a product of lactic acid fermentation. Accordingly, lactic acid-producing bacteria with the inoculums in 5 amount sufficient to outgrow bacteria, yeast or moulds present in the feed material present in the feed material to be fermented. Thus in one embodiment, the bacteria present in the inoculum of step (a) are essentially lactic acid-producing bacteria and where the concentration of lactic acid-producing bacteria in the inoculum of step (a) are sufficient to outgrow any bacteria, yeast or moulds 10 present in the feed material of step (ii) or at least significantly inhibit further proliferation of said bacteria, yeast or moulds.

Dry fermented feed product

The method according to the present invention provides a dry fermented feed 15 product.

The dry fermented feed product obtained by the method of the present invention may be mixed with other dry fermented feed products such as a dry fermented feed product obtained by the method of the present invention using different 20 fermented feed products as the starting material.

It should be noted that embodiments and features described in the context of one of the aspects of the present invention also apply to the other aspects of the invention.

25

The invention will now be described in further details in the following non-limiting examples.

Examples 30 Example 1

Fermented feed comprising large amounts of lactic acid producing bacteria was obtained by providing an inoculum comprising lactic acid producing bacteria and mixing the inoculum with a feed material (including rape) and fermenting the mixture to obtain a fermented feed (liquid feed). Samples of the fermented feed 16 DK 177482 B1 were subjected spin flash drying and conventional drying in the form of toasting, respectively. The counts of viable bacteria in the feed were measured. The data are presented in table 1 below:

Bacterial counts CFU (log CFU)

Lactic acid

Drying Entero- Clostridium producing Yeast Moulds method bacteria perfrigens bacteria 3400000 <1000 7273

Liquid feed <1000 (<3) 2000 (3.3) (6.53) (<3) (3.86)

Dry feed, <1000 2700

Toasting <1000 (<3) 36364 (4.56) <1000 (<3) (<3) (3.43) (max 63°C)

Dry feed, 152727 <1000 1800

Toasting <1000 (<3) <1000 (<3) (5.18) (<3) (3.26) (max 50°C)

Dry feed, 45000000

Spin flash <1000 (<3) <1000 (<3) 2000 (3.3) 200 (2.30) (max 56°C) (?'65) 5

The above data demonstrate that lactic acid producing bacteria in fermented feed are sensitive to the drying method applied to produce dry fermented feed from (semi)liquid feed. The data surprisingly demonstrate that spin flash drying may success be applied in order to obtain a dry fermented feed with a high count of 10 viable lactic acids producing bacteria.

References WO 97/19307 (APV Anhydro A/S)

Claims

A process for preparing a dry fermented feed product comprising the steps of: (a) providing a fermented feed product wherein the feed product comprises 5 lactic acid bacteria; (b) introducing the feed product from (a) into a drying chamber in a spin flash dryer; (c) contacting the feed product from (a) with a stream of drying gas in the drying chamber, and (d) obtaining a dry fermented feed product. 10

The method of claim 1 comprising the steps of: (a) providing a fermented feed product, wherein the feed product comprises lactic acid bacteria by (i) providing an inoculum comprising bacteria, (ii) providing a feed material; (iii) combining the materials of step (i), (ii) and fermenting the feedstock of step (ii) using the inoculum of step (i) to obtain the fermented feed product; (b) introducing the fermented feed product from (a) into a drying chamber in a spin flash dryer; (c) contacting the fermented feed product from (a) with a stream of drying gas in the drying chamber, and (d) obtaining a dry fermented feed product.

The process of claim 1 or 2, wherein the fermented feed product obtained in step (a) is obtained by fermenting one or more of whey, curd, mash, yeast, fungus, bacteria, plants or parts thereof, and potatoes or portions thereof. .

Process according to any one of the preceding claims, wherein the fermented feed product provided in step (a) has been fermented for 12-24 hours. 2 DK 177482 B1

The method of any one of claims 2-4, wherein the inoculum comprises lactic acid bacteria and wherein the lactic acid concentration in the fermented feed obtained by the fermentation in step (a) is higher than that in the inoculum. 5

The method of any of claims 2-4, wherein the inoculum comprises lactic acid bacteria and wherein the fermented feed product provided in step (a) has a lactic acid concentration in the range of 100-150 mM.

The method of any of claims 2-4, wherein the inoculum comprises lactic acid bacteria and wherein the fermented feed product provided in step (a) has a lactic acid concentration in the range of 150-200 mM.

A process according to any one of the preceding claims, wherein the inlet temperature of the drying gas is in the range of 120 to 160 ° C.

A method according to any one of the preceding claims, wherein the moisture content of the feed product obtained in step (d) is in the range of 5 to 15% by weight (w / w%). 20

A method according to any one of the preceding claims, wherein the moisture content of the feed provided in step (a) is in the range of 25 to 95%.