WO2018127341A1

WO2018127341A1 - Process for preparing an alcoholic fermented beverage with the aid of nutrients and use of such nutrients

Info

Publication number: WO2018127341A1
Application number: PCT/EP2017/081507
Authority: WO
Inventors: Deepak Kumar; Vijay Singh; Anna-Sophie HAGER; Adam Griffith; Alberto SUN
Original assignee: Anheuser-Busch Inbev S.A.
Priority date: 2017-01-06
Filing date: 2017-12-05
Publication date: 2018-07-12
Also published as: AR110315A1; BE1025452B1; BE1025452A1

Abstract

A process for preparing an alcoholic fermented beverage, the process comprising the steps of: a. Slurrying a starch source in water; b. Subsequently liquefying the starch to obtain a wort or most; c. Optionally boiling the wort or most and subsequently diluting the boiled wort or most with water; d. Fermenting the wort or most; e. Postfermentation processing the fermented wort or most obtaining the alcoholic beverage; characterized in that waterextracted nutrients from cereal germ are provided either in the starch source in water slurry or in the wort or most.

Description

PROCESS FOR PREPARING AN ALCOHOLIC FERMENTED BEVERAGE WITH THE AID OF

NUTRIENTS AND USE OF SUCH NUTRIENTS

TECHNICAL FIELD

The present invention concerns a process for preparing an alcoholic fermented beverage, wherein nutrients are provided during fermentation that improve yeast performance during the fermentation process. BACKGROUND OF THE INVENTION

Use of adjunct grains during brewing is believed to aid in achieving certain flavor profiles, increase extract yield, beer stability, and reduce brewing cost. Corn grits are most commonly used adjuncts in United States, especially for lager beers. Main challenge of using adjunct grains in the brewing process is protein di lution in wort. Most of the adjuncts used in the industry, including corn grits, have very low soluble protein content and cause protein dilution in fermentation wort. The protein dilution affects the growth and functioning of yeast during fermentation. The problem is often addressed by adding externa l nutrition. The objective of this invention is to develop economica l process strategies to improve the fermentation performance during brewing process by providing these nutrients from other, preferably cerea l based origin.

SUMMARY OF THE INVENTION The present invention is defined in the appended independent claims. Preferred embodiments are defined in the dependent claims. I n pa rticular, the present invention concerns process preparing an a lcoholic fermented beverage comprising the steps of:

a. Slurrying a starch source, preferably a cereal-starch source in water;

b. Subsequently liquefying the (cereal-)starch to obtain a wort or most;

c. Optionally boiling the wort or most and subseque ntly diluting the boiled wort or most with water;

d. Fermenting the wort or most; e. Post-fermentation processing the fermented wort or most obtaining the alcoholic beverage;

characterized in that water-extracted nutrients from cereal germ are provided either in the (cereal-)starch source in water slurry or in the wort or most.

The water-extracted nutrients can be provided as a liquid solution, a concentrated solution, a pasta, gel or in a dry phase.

The nutrients are preferably extracted from cereal germ by soaking the cereal germ in water for at least 2 hours, preferably at least 12 hours or even at least 24 hours at between 20° C and 60° C, thereby obtaining germ water, additionally the nutrients in the germ water can be concentrated or dried.

The germ water may be treated with/subjected to at least a protease allowing break-down of proteins in the germ water to amino acids.

The process according to the present invention may further comprise filtering the cereal germ/water mixture to obtain germ water. The process according to the invention may also comprise slurrying the cereal-starch source in water comprising water-extracted nutrients from cereal germ and subsequently liquefying the cereal-starch with an enzyme mixture comprising a protease.

The cereal (or tuber) used as starch source is preferably selected from the group comprising: corn, wheat, barley (including malt), rice, sorghum, oat, cassava and/or mixtures thereof. The cereal germ is preferably a germ obtained from corn, wheat, barley, rice, sorghum, oat and/or mixtures thereof and might be a spent germ.

The process according to the present invention is particularly useful when the cereal used as starch source for preparing the beverage comprises between 0 and 80 w% of malt. The process according to the present invention may comprise slurrying a first (cereal-)starch source and a second (cereal-)starch source separately of one a nother in water, wherein at least one of the first and second (sta rch-)sources is slurried in water comprising water- extracted nutrients from cereal germ. In such case, the first (cereal-)starch source is preferably malt and the second (cereal-)starch source is preferably: i) slurried in water comprising water-extracted nutrients from cereal germ and ii) liquefied; prior to mixing the second starch source with the malt.

I n a process according to the present invention, B-vita mins may be added to the slurry in steps a) or b), to the most or wort in step c) or during fermentation (step d).

The present invention also concerns the use of water-extracted nutrients from non-malt cereal germ as a fermentation aid in the preparation of a beverage and beer in particular. BRIEF DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the nature of the present invention, reference is made to the following detailed description ta ken in conjunction with the accompanying drawings in which:

Figures 1 shows a flow-sheet of several process steps of a process according to the present invention;

Figure 2 shows a graph with ethanol and sugar concentrations during fermentation with and without (control) water-extracted germ nutrients during a process of preparing an alcoholic beverage as shown in Figure 1;

Figure 3 shows a flow-sheet of several process steps of an a lternative process according to the present invention;

Figures 4 and 5 show a graph with respectively ethanol and maltose concentrations during fermentation with and without (control) water extracted germ nutrients during a process of preparing an alcoholic beverage as shown in Figure 3; Figure 6 shows a graph of the ethanol production rate during fermentation with and without (control) water extracted germ nutrients during a process of preparing an alcoholic beverage as shown in Figure 3;

Figure 7 shows a same graph as figure 6, yet for the ethanol production rate during fermentation with and without (control) water extracted germ nutrients during a process of preparing an alcoholic beverage as shown in Figure 3 and additionally for a fermentation with both water extracted germ nutrients and B-vitamins;

Figure 8 shows a further alternative process of figures 1 and 3 according to the present invention.

DEFINITIONS

For the sake of the present invention, cereal germ is defined as the embryo of a cereal grain. Cereal germ, in particular corn germ, is recovered in commercial dry-milling and wet-milling process. Corn germ can also be obtained in a dry grind process (used for bioethanol production) using method described in US2005009133 (Johnston & Vijay) and involves soaking corn kernels in water to produce soaked corn kernels, grinding the soaked corn kernels to produce a ground corn slurry, and incubating the ground corn slurry with at least one enzyme (amylase(s), protease(s), cell wall degrading enzyme(s), or mixtures thereof, and optionally other enzyme(s)) to increase the specific gravity of the slurry to about 10- about 16 Baume so that the corn germ and corn coarse fiber floats to the top of the slurry, recovering the corn germ.

Germ water is defined as water comprising soluble nutrients extracted from a cereal germ by water extraction, preferably at a temperature ranging between 20°C and 60°C, preferably between 30°C and 55°C.

Cereal germ and corn germ in particular, are used for oil extraction, such as by solvent extraction (e.g., ethanol, acetone, ether, hexane, etc.), thereby generating oilseed meal as a side product. For the present invention this oilseed meal is further referred to as spent germ. DETAILED DESCRIPTION OF THE INVENTION

The present invention concerns a process for preparing an alcoholic beverage with the aid of nutrients and comprises the steps of:

a. Slurrying a (cereal-)starch source in water;

b. Subsequently liquefying the (cereal-)starch to obtain a wort or most;

c. Optionally boiling the wort or most and subsequently diluting the boiled wort or most with water;

d. Fermenting the wort or most;

e. Post-fermentation processing the fermented wort or most obtaining the alcoholic beverage.

In particular for brewing processes wherein a high amount of adjuncts is used as a starch- source, it is known that fermentation can slow down considerably or get stuck due to a drop in yeast viability. The drop in yeast viability can have several reasons, one of which is a lack of nutrients available for the yeast metabolism to function correctly. It is known in such cases that the addition of nutrients to the fermentation can solve the above problem. Yeast nutrients however are known to be expensive. The objective of the present invention is to develop process strategies to improve fermentation performance in beverage alcohol production. The gist of the invention is the finding that the presence/addition of water-extracted nutrients from cereal germ to the (cereal-)starch source in water slurry or in the wort or most increases the fermentation rate and/or the RDF (real degree of fermentation).

Figure 1 illustrates some process steps of a process according to the present invention wherein an alcoholic fermented beverage is prepared starting from two distinct starch sources. The first starch source, showed on the right-hand side is a malt that is first grinded, subsequently soaked (slurried) in water and provided in a mash tun. Mashing is performed to convert starch in the grain into sugars to create a malty liquid called wort. The second starch source is a non-malted (adjunct) cereal processed by dry-milling, wet-milling, dry- grinding or other fractionation processes separating the starch from the bran, germ and alleurone. The starch fraction is subsequently slurried in germ water (nutrient source), liquefied by enzymatic action (breaking down the starch polymer in, mainly, oligosaccharides), and hydrolyzed by enzymatic action (breaking down of oligosaccharides into fermentable sugars such as glucose). This slurry is combined with wort obtained from malt mashing and can subsequently be boiled. After the optional boiling step, the wort is preferably filtered while transferring it to the fermentation vessel for performing the fermentation.

By adding the water-extracted germ nutrients in the adjunct slurry or during liquefaction of the adjunct starch, the water-extracted germ nutrients can be subjected to an enzymatic treatment, which in case protease activity is present, allows breaking down even more of the germ proteins and peptides into short amino acid chains or free amino acids, thereby preventing precipitation of these nutrients during an optional boiling of the wort or most. In this case the water-extracted cereal germ nutrients are added as so-called germ water, but it is clear that the nutrients can also be added as a concentrated solution, a pasta, a gel or in a dry phase as e.g. powder.

The ratio of malt/adjunct used for preparing the alcoholic beverage of the present invention preferably ranges between 0/100 to 80/20. The amount of germ used for extracting the germ nutrients preferably ranges between 20 and 60 w%, preferably between 20 and 50 w%, of the amount of adjunct used. Germ water is added to the adjunct slurry or during liquefaction of the starch per kilogram of adjunct such that preferably 180 to 720 mg of FAN (free amino nitrogen) is added to the adjunct slurry or during liquefaction of the starch per kilogram of adjunct. Clearly, the germ water comprises other nutrients than just FAN, yet the nutrients in the germ water are usually high in FAN (for 1:10 germ:water ratio used for extraction, FAN concentrations of 90 to 120 ppm were observed).

An advantage of use of germ water as nutrient source is that the germ water contains low amounts of lipids. The amount of crude FAT originating from cereal germ preferably does not exceed an amount of 350 mg per kg of adjunct used, is preferably even lower than 200 mg per kg of adjunct used and even more preferably even lower than 35 mg/kg of adjunct used (for 1:10 germ:water ratio used for extraction, crude fat concentrations of less than 5 to about 35 ppm were observed, whilst in the same germ water, FAN concentrations varied between 90 - 120 ppm). Starch sources that can be used as adjunct comprise corn, wheat, barley, rice, sorghum, oat, cassava and/or mixtures thereof. The cereal germ used for the extraction of nutrients can be originating from the same or a different source of cereal as the adjunct starch and preferably originates from corn, wheat, barley, rice, sorghum, oat and/or mixtures thereof, corn germ being most preferred.

The cereal germ used in the present invention can also be a so-called spent germ, which is a side product of oil extraction, such as by solvent extraction (e.g., ethanol, acetone, ether, hexane, etc.) from cereal germ, thereby generating oilseed meal herein addressed as spent germ. Alternatively, in case regular cereal germs (not so-called spent germ) is used in a present invention, the solids - remaining after water extraction of the nutrients from the cereal germ - can be used for oil extraction. Due to leaching of micronutrients and soluble proteins (by water extraction), the oil concentrations in the germ solids increases by about 25% compared to raw germ, which would enhance its economic value. Figure 2 shows a graph with ethanol and sugar concentrations during fermentation with and without (control) water extracted germ nutrients during a process of preparing an alcoholic beverage as shown in Figure 1 with a malt/adjunct ratio of 60/40 and the cereal germ being a corn germ. As can clearly be deducted from the graph, the addition/presence of water-extracted cereal germ nutrients considerably improves maltose digestion rate (indicating increased fermentation rate (speed)) and increases ethanol production (yield).

Figure 3 illustrates some process steps of an alternative and conventional brewing process according to the present invention wherein an alcoholic fermented beverage is prepared starting from two distinct starch sources. The first starch source, showed on the right-hand side is a malt that is first grinded, subsequently soaked (slurried) in water and provided in a mash tun. The second starch source is a non-malted (adjunct) cereal processed by dry- milling, wet-milling, dry-grinding or other fractionation processes separating the starch from the bran, germ and alleurone. The starch fraction is subsequently slurried in germ water and liquefied by enzymatic action (breaking down the starch polymer in, mainly, oligosaccharides). The liquefied adjunct starch is subsequently added to the malt slurry in the mash tun and mashing is performed to break down the starch and oligosaccharides in the grain into sugars to create a malty liquid called wort or most which can subsequently be boiled. After the optional boiling step, the wort is preferably filtered while transferring it to the fermentation vessel for performing the fermentation.

Again, in this case the water-extracted cereal germ nutrients are added as so-called germ water, but it is clear that the nutrients can also be added as a concentrated solution, a pasta, a gel or in a dry phase as e.g. powder thereby allowing addition of the nutrients without diluting the wort or most.

Figure 4 and 5 show a graph with respectively ethanol and maltose concentrations during fermentation with and without (control) water extracted germ nutrients during a process of preparing an alcoholic beverage as shown in Figure 3 with a malt/adjunct ratio of 60/40 and the cereal germ being a corn germ. The amount of germ used for extracting the germ nutrients in this case is 50 w% of the amount of adjunct used (soaking the germ in water (l/10w% germ/water ratio) for 12 hours at 52°C with continuous shaking 125 rpm and subsequent filtering).

These graphs clearly indicate a higher fermentation rate in case water-extracted germ nutrients are provided to the wort/most (increased rate of alcohol production and increased rate of maltose digestion). The ethanol production rate for the above experiment is also illustrated in the graph of Figure 6.

It was further observed that the addition of B-vitamins in combination with the addition water-extracted germ nutrients allows further increasing the fermentation rate. Figure 7 shows a graph of the ethanol production rates during fermentation in a process according to the present invention for a process without the addition of nutrients (control), a process wherein only water-extracted germ nutrients were added and a process wherein apart from water-extracted germ nutrients also B-vitamins were provided in the wort/most.

A B-vitamin complex essentially comprises of co-enzymes involved in a carbohydrate metabolism providing metabolic precursors for yeast growth.

Figure 8, illustrates an alternative process of figures 1 and 3, wherein the water-extracted germ nutrients are added to the malt mash, prior to, during or after addition of the liquefied adjunct starch thereto. By addition to the malt mash, the water-extracted germ nutrients are not exposed to the relative high temperatures (85°C) of the liquefaction process of the adjunct starch and are subjected to the enzyme treatment of the mashing process (malt enzymes or additional external enzyme mixtures) thereby allowing further breaking down the proteins in the germ nutrients into short amino acid chains or free amino acids that do not precipitate when boiling the wort/most.

While the above description focusses in particular on the process of the invention to prepare an alcoholic fermented beverage and beer in particular, it is clear that the use of water-extracted nutrients from non-malt cereal germ as a fermentation aid in the preparation of a beverage and beer in particular is also part of the present invention.

It is clear that water-extracting nutrients from cereal germ (including spent germ) to obtain germ water, this germ water or a concentrated form thereof (concentrated solution, pasta, gel or dry form) can be stored, transported and used as a fermentation aid to increase fermentation rates and/or increase ethanol production during beverage manufacturing.

In accordance with the present invention, the germ water is preferably prepared by:

i) Soaking cereal germ (might be spent germ, a mixture of germ from different cereal sources or a mixture of spent germ with other germs) in water (eg. at a weight ratio ranging between 1:5 to 1:20 germ:water) ii) Incubating the germ in water mixture at a temperature between 20°C and 60°C, preferably between 30°C and 55°C, during at least 12 hours or even 24 hours and preferably with continuous stirring or shaking; and subsequently

iii) Preferably filtering the mixture to obtain the germ water.

It is noted that in accordance with the above method of preparing the germ water, the use of water is preferably limited, therefore a 1:5 germ:water ratio is preferred over a 1:20 germ:water ratio, provided a same absolute amount of nutrients can be extracted from the germ into the water.

For 1:10 germ :water ratio used for extraction, FAN concentrations of 90 to 120 ppm were observed in the germ water, while crude fat concentrations remained below 50 ppm and in most cases did not exceed 35 ppm or even 5 ppm.

Claims

1. A process for preparing a alcoholic fermented beverage, the process comprising the steps of:

a. Slurrying a starch source, preferably a cereal-starch source in water;

b. Subsequently liquefying the starch to obtain a wort or most;

d. Fermenting the wort or most;

e. Post-fermentation processing the fermented wort or most obtaining the alcoholic beverage;

characterized in that water-extracted nutrients from cereal germ are provided either in the starch source in water slurry or in the wort or most.

2. The process according to claim 1, comprising providing the water-extracted nutrients as a liquid solution, a concentrated solution, a pasta, gel or in a dry phase.

3. The process of claim 1, comprising extracting nutrients from cereal germ by soaking the cereal germ in water for at least 2 hours, preferably at least 12 hours or even at least 24 hours at between 20° C and 60° C, thereby obtaining germ water.

4. The process according to claim 3, comprising the step of concentrating and/or drying the germ water.

5. The process according to claims 3 or 4, comprising treating the germ water with at least a protease allowing break-down of proteins in the germ water to amino acids.

6. The process according to any of claims 3 to 5, comprising filtering the cereal germ/water mixture to obtain germ water.

The process according to any of claims 1 to 6, comprising slurrying the starch source, preferably the cereal-starch source in water comprising water-extracted nutrients from cereal germ and subsequently liquefying the cereal-starch with an enzyme mixture comprising a protease.

The process according to any of the preceding claims, the starch source is selected from the group comprising: corn, wheat, barley (including malt), rice, sorghum, oat, cassava and/or mixtures thereof.

The process according to any of the preceding claims, wherein the cereal germ is a germ obtained from corn, wheat, barley, rice, sorghum, oat and/or mixtures thereof.

The process according to any of the preceding claims, wherein the cereal germ is a spent germ.

The process according to claim any of the preceding claims, cereal used as starch source for preparing the beverage comprises between 0 and 80 w% of malt.

The process according to any of the preceding claims, comprising slurrying a first starch source, preferably a cereal-starch source, and a second starch source, preferably a cereal-starch source, separately of one another in water, wherein at least one of the first and second starch-sources is slurried water comprising water- extracted nutrients from cereal germ.

The process according to claim 10, comprising the first starch source is malt and the second starch source is: i) slurried in water comprising water-extracted nutrients from cereal germ and ii) liquefied; prior to mixing the second starch source with the malt.

14. The process according to any of the preceding claims, comprising adding B-vitamins to the slurry in steps a) or b), to the most or wort in step c) or during fermentation (step d). Use of water-extracted nutrients from non-malt cereal germ as a fermentation aid the preparation of a beverage and beer in particular.