CZ300164B6 - Preservation method of fresh hop - Google Patents

Abstract

The present invention relates to a method of preserving fresh-harvested hop wherein the method is characterized in that fresh preliminary cooled hop is subjected to homogenization in vacuum or in inert atmosphere, the homogenization product is then enclosed in barrier packages being impermeable to oxygen and subsequently it is processed by the action of a pressure liquid, preferably potable water with temperature ranging from 5 to 40 degC, pressure of 100 to 800 MPa for a period of 60 minutes to cold pasteurize thereof. So processed hop can be stored in a cold storage warehouse without reduction of its quality if compared with fresh hop, at least for a period of one year.

Description

The invention relates to a method of preserving freshly harvested hops in the form of a homogenate. which is stored at refrigerated temperatures in the non-frozen state.

Hitherto celebrated techniques

Freshly harvested hop cones contain approximately 75 wt. water. The combed hop sc is dried immediately after harvesting to a residual moisture content of 10% by weight. ± 2% to prevent product degradation by evaporation. For this purpose, hot air driers of various constants (chamber, belt) are used. Drying is carried out at temperatures of 55 ± 5 ° C for 6 to 12 hours. The residual water content of the dried hops is very important because at humidity levels above 12 wt. there is a risk of self-ignition of the hops. At a low water content below 8 wt. hop cones become fragile, splitting into bracts, leading to loss of the desired lupine lupine and difficulties in further handling. Virtually all hops are currently processed into hop products, which are mainly hop granules (2/3 of the harvest) and extracts (1/3). The main advantage of hop products in comparison with hops, in addition to a significant reduction in storage and transport costs, is primarily the stabilization of the content of bitter acids and other brewery valuable substances. Both bitter hop acids and hop oils are relatively unstable. Alpha and beta bitter acids are irreversibly transformed into non-specific resins when exposed to air.

essential oils are volatilized and oxidized, especially some terpenic components. All this has the effect of reducing the brewing value of hops. Processing into hop products slows this process considerably, even if it does not stop completely. Despite the careful processing conditions of freshly harvested hops, some changes in the content and composition of secondary metabolites still occur. A further disadvantage of the prior art hops storage method is the need to evaporate the water, since it has to be supplied

5 (> evaporative heat, which represents a huge energy cost.

In the past, attempts have been made to preserve fresh hops in a frozen state, while maintaining the high quality of the hops, but the method has not been adopted since it is necessary to freeze large volumes of hops as well as energy costs for smoothing. they are considerable and breweries do not have the storage capacity for frozen products.

SUMMARY OF THE INVENTION

The above-mentioned disadvantages are eliminated by the method of keeping the hops fresh according to the invention, which is based on this. that the fresh hopped hopper with possible addition of drinking water in the amount of up to 2 liters per 1 kg of hop is homogenized under vacuum or under a protective atmosphere to a concentrated suspension, whereupon the hop suspension is filled into barrier packages which

4? After being sealed, it is placed in a high pressure chamber and pressurized at 5 to 40 ° C with a pressure of 100 to 800 MPa for up to 60 minutes, then the filled and sealed packages are placed in a cold storage room at normal cold temperature.

The method according to the invention is characterized by this. That the fresh predell-laden hops are homogenized with the possible addition of drinking water in an amount of up to 0.2 to 0.3 liters per kilogram of hops.

The method according to the invention is further characterized in that. that the homogenization takes place under a protective atmosphere.

The process of the invention is characterized in that the pressurized liquid is water.

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The method of the invention is further characterized by that. The cold pasteurization of the hop suspension in the packages takes place at a pressure of 400 to 600 MPa for 5 to 25 minutes.

The process according to the invention is further characterized in that the hop suspension is filled into barrier packages which are particularly impermeable to oxygen.

The process according to the invention makes it possible to preserve all the ingredients in comparison with fresh hop cones without having to dry or extract them or freeze them. Therefore, it reduces the overall energy consumption of the hop-keeping process compared to the existing methods. It also inactivates living cells of microorganisms, especially fungi and yeasts, thus enabling the so-called cold hopping of beer and hop soft and mime alcoholic beverages, where it is important to preserve all nutritionally and healthly important components of the hops. . According to the method of the invention, fresh hops are homogenized and cold pasteurized so that the quality of the hops is not reduced compared to fresh hops for at least one year of storage if the hops are sealed. It is preferred that the size of the packages be selected as needed so that the hop content can be consumed once when the package is opened. However, this does not impose any additional requirements on the method of preserving the hops of the invention. The hops thus treated are widely used in the food, pharmaceutical and cosmetics industries as they do not lose their nutritional value during storage, as is the case with conventional methods. Storing containers with hop suspension does not increase the space requirement for keeping fresh hops for longer periods.

The following examples illustrate the process according to the invention, but do not limit it in any way.

DETAILED DESCRIPTION OF THE INVENTION

EXAMPLE 1 kg of fresh pre-seeded hops are placed in a homogenizer equipped with a nitrogen protective atmosphere and homogenized. The suspension is then filled into a PE / Al foil wrapper and heat sealed. Make sure that there is a minimum amount of air in the package. The package is placed in a high pressure isostatic press chamber (e.g. from Žďas a.s,). With a chamber volume of 125 liters, where it is drenched with potable water, the chamber is sealed and additional potable water at a temperature of 12 ° C is pumped until a pressure of 500 MPa is generated inside the chamber. The pressure is held for 10 minutes and then the water pressure is reduced to zero by opening the pressure relief valve 40. This sc performs the cold hop suspension pasteurization. The package is then placed in a cold store where it is stored at temperatures from 0 to + 10 ° C. Until the package is opened, no undesirable microorganisms develop and no loss of hops is present. Therefore, it is appropriate to adjust the size of the package to the hop dose for hopping a given batch of beverage in order to utilize the contents of the package all at once.

Example 2

100 kg of fresh pre-chilled hops shall be placed in a homogenisation equipment, which shall be equipped by vacuuming the space above the homogeneous enclosure in the hopper and homogenized. This gives a hop suspension which optimally contains 0.2 liters of added water per kilogram of hops. The sc suspension is then filled into a PE / Al foil wrapper and heat sealed. Make sure that there is a minimum amount of air in the package. The container is placed in a chamber of a high pressure isostatic press (e.g. from Žďas a.s), with a chamber volume of 125 liters, where it is filled with potable water, the chamber is sealed and pumped further drinking water at a temperature of 15 ° C.

C7. 300164 B6 until a pressure of 600 MPa is formed inside the chamber. Hold for 15 minutes and then reduce the water pressure to zero by opening from (paint valve, lim pasteurization with cold hop suspension), then place the container in a cold store where it is stored at 0 to + 12 ° C. Until the package is opened, undesirable microorganisms and hop contents are not lost, therefore it is appropriate to adjust the package size to the hop dose for hopping a given batch of beverage in order to utilize the package contents all at once.

Industrial applicability

The solution makes it possible to maintain the quality of the hops at the level of fresh hops for at least the next harvest under refrigeration temperature conditions, which can normally be achieved without additional technological costs. Cold pasteurization inactivates the living microorganisms present in the hop suspension and thus prevents its microbial spoilage. This solution makes it possible to produce especially particular types of beer and hop beverages with favorable nutritional and health benefits and especially so-called cold hopping. The solution eliminates the need to dry or freeze the hops.

Claims (6)

What is claimed is: 1. A method of preserving fresh hops, characterized by: that the fresh pre-chilled hops, possibly containing up to 2 liters per kilogram of hops, are homogenized under vacuum or under a protective atmosphere to a concentrated hop suspension, whereupon the hop suspension is filled into barrier packages which are placed in the high pressure chamber after closure; pressurized with a pressurized liquid at a temperature of 5 to 40 ° C at a pressure of 100 to 800 MPa for up to 60 minutes, then reduce the pressure of the liquid to zero and place the filled and closed packages in a cold storage room at normal cold temperature. Method according to claim 1, characterized in that. This means that the fresh pre-screened hops are homogenized with a possible addition of potable water of up to 0.2 to 0.3 liters per kilogram of hops. A method according to claim 1, characterized in that. that the homogenization takes place under a nitrogen atmosphere. A method according to claim 1, characterized in that the method is as follows. that the pressurized liquid is water. Method according to claim 1, characterized in that the cold pasteurization of the hop suspension in the packages takes place at a pressure of 400 to 600 MPa for 5 to 25 minutes. A method according to claim 1, characterized in that. The hop suspension is filled into barrier coatings which are particularly impermeable to oxygen.