WO1995001292A1

WO1995001292A1 - Packaging of enzymes

Info

Publication number: WO1995001292A1
Application number: PCT/EP1994/002151
Authority: WO
Inventors: Roland Cocker
Original assignee: Quest International Bv.
Priority date: 1993-07-02
Filing date: 1994-06-30
Publication date: 1995-01-12
Also published as: AU7073994A

Abstract

By using bag-in-box type or bag-only containers instead of traditional drum-type containers for packaging it may be possible to reduce the amount of stabilizers and/or preservatives generally needed to maintain acceptable enzymatic activity of enzyme solutions or dispersions packed in drum type containers. This is probably due to aseptic and anaerobic packaging as well as to prevention of headspace volume formation.

Description

PACKAGING OF ENZYMES

The invention relates to a novel method for packaging enzyme solutions or dispersions as well as to the packaged enzymes themselves.

An important form in which enzymes are offered for sale is in the form of a liquid. Since enzymes themselves are mainly solids, such enzymes may be dissolved or dispersed in a suitable liquid to obtain the enzymes in a liquid form. Other methods for obtaining enzymes in a liquid form may also be applied. Although a conventional liquid used for the preparation of such a solution or dispersion is water or an aqueous liquid, the invention may also be applied to enzymes dissolved or dispersed in other liquids. For the purpose of the invention, it is herein to be understood that "enzyme solutions" comprises all liquid forms of enzymes.

Since most enzymes are degraded rapidly by microbial spoilage and/or by the influence of oxidizing compounds such as air, stabilizers and/or preservatives (antimicrobial compounds) are generally added to the enzyme solutions to maintain enzymatic activity over a sufficient period of time. Examples of preservatives are e.g. Na- benzoate, Na-sorbate, K-sorbate, Na-metabisulphite, and Na- parabens. Enzyme stabilizers include salts (e.g. KC1, NaCl or sulphates) , humectants, proteins, amino acids, sugars and sugar alcohols, alcohols and polyols like glycerol. In some cases, the amount of stabilizer can be quite large. When for example glycerol is used as a stabilizer for the enzyme" invertase, the amount of glycerol can be up to 50% of the total volume of the stable enzyme solution. It will be clear that the use of stabilizers in this respect is considered to be inconvenient and burdensome. The high volume of stabilizer to be used has a negative effect on the cost of packaging, storage and transport. Furthermore, the concentration of the enzymes is limited as the product or mixture to which such a stabilized enzyme solution is added will be diluted thereby, which can be undesirable in some cases.

An additional disadvantage that applies both for preservatives and stabilizers is that they will not always be compatible with the products or mixtures to which the enzymes are to be added. An even further disadvantage is that due to the need to use stabilizers (and in many cases quite substantial amounts) and/or preservatives the price of the enzymes per unit activity will go up.

Additionally, it is desired more and more by the enzyme users that enzymes can be supplied without stabilizer and/or preservatives added thereto, or at least a reduced amount of one or more of these compounds. This applies especially to preserved enzymes which are to be used in foods or foods applications, since preservatives are generally considered as a chemical additive by the customer and the use of preservatives in foodstuffs has a negative image.

The disadvantages listed above indicate that there is a need for packed, easy to use enzymes with a reduced amount of stabilizer and/or preservative, and more preferably, without any substantial amount of stabilizer and or preservative added thereto at all.

It has now been found that these objectives can be met by using a so called (aseptic) bag-in-box type of packaging. This type of packaging allows a decrease of the amount of stabiliser and/or preservative. Such a decrease may be that large that no substantial amount of stabiliser and/or preservative is needed for keeping the quality of the enzyme long enough within specification. Such a type of packaging exists in many different varieties, but they all have in common that they comprise at least a flexible, liquid-tight container (e.g. made from a flexible plastic bag) with at least one opening for filling and emptying the container and a more or less rigid supportive member surrounding the flexible container. Such a supportive member may be made of materials such as steel, wood, carton, cardbox, rigid plastic, etcetera. Different forms and shapes of the rigid supportive member are possible, and include box-shaped and cylinder shaped models. The bag is preferably composed of a material which is impermeable for oxygen.

The bag-in-box type containers as mentioned in the preceding paragraph are well known in the art for e.g. wine, milk and cream. They are used for such purposes to prevent microbial spoilage and oxidation of the liquid contained therein.

Previously, it was not thought possible to reduce or even omit stabilisers and or preservatives when storing enzyme solutions, unless one accepts a short shelf life stability when unopened, and an even shorter shelf life once opened. For example, in WO 88/03900 bag-in-box type packaging is suggested for enzymes, but it is mentioned that such an enzyme still contains glycerol, which is a well known enzyme stabiliser. Thus, one concludes that reducing the amount of stabilizer and or preservative when packing enzymes is not possible up till now, let alone omitting them.

Prevention of microbial spoilage and oxidation of enzyme solutions can be well achieved by conventional means (i.e. stabilizers and/or preservatives) , but what could not be achieved in the packaging of enzyme solutions up till now is a reduction of the amount of stabilizers and/or preservatives used. In the present invention, for some enzymes the stabilizers and/or preservatives can even be substantially left out, whilst the enzymatic activity is well maintained. By using a bag-in-box type packaging, it is possible to keep the enzyme solution in an anaerobic, aseptic way for a prolonged time.

Thus, one embodiment of the invention is a packed enzyme solution or dispersion, characterized in that the enzyme solution or dispersion is contained in a bag-in-box type container. In many cases, the amount of stabilizer and/or preservative normally needed when using rigid containers can be reduced. Preferably, an enzyme solution packed according to the invention contains less than 30% by weight, preferably less than 10% by weight of a stabiliser.

For some purposes, substantially no stabilizer and/or preservative at all will be needed in the packed enzyme solution according to the invention. This is of course the most preferred embodiment.

It may also be possible to eliminate the need for reducing the pH value to 4.5 or below, which is another method of avoiding microbial contamination.

One can distinguish two different shelf life stabilities: one relating to a packed product which is not opened for use (period starts to run from date of packing the product) . Another shelf life stability for a packed product relates to a shelf life stability for a product once the protective packaging material is opened (such a period starts to run from the first usage) .

The method of packaging according to the invention is suitable for all sorts of enzymes including proteases, peptidases, lipases, and carbohydrate modifying enzymes. The method according to the invention works especially well with the carbohydrate modifying enzyme invertase, which used to comprise up to 50% of its volume of glycerol as a stabilizer. This can now be substantially reduced or even completely omitted.

Although bag-in-box as well as bag-only packaging is known for the packaging of enzyme containing liquid detergent compositions, these packed detergent compositions are not subject of this invention. The invention applies to packaging enzyme solutions or dispersions wherein the enzyme is the main active component and not an additive, as in the case of e.g. detergent compositions. In this respect, solvents, carriers, diluents etc. are not considered to be main active components.

The bag-in-box type packaging as disclosed above is very well suitable to replace the conventional drum type of packaging. An even more simple type of packaging can be achieved, however, for applications wherein the whole content of a container is used at once (i.e. one shot use or use. within one day) . Herein a simple bag can be used, preferably without the rigid supportive member and preferably even without complicated emptying valves. The customer wishing to use e.g. 4 litres of an enzyme solution simply orders a 4 litre bag of the right enzyme solution, opens it and pours the total content in the equipment where the enzyme is needed. For this type of packaging the same decrease in stabilizer and/or preservative can be achieved. The empty package remaining is environmentally friendly, and can simply be recycled or burned, without leaving any residual enzymes. When using the conventional drum type packaging, such drums have to be cleaned, either by the customer or by the supplier (in the case of return drums) , which increases costs and risk of contamination of the environment with residual enzymes as well as the risk of formation of hazardous aerosols. Therefore, another embodiment of the invention is enzyme solutions or dispersions packed in a simple bag type container. The same type of bags can be used as. in the bag- in-box type packaging. Similar advantages as for the bag- in-box type packaging w.r.t. the use of stabilizers and/or preservatives as well as to the pH of the solution apply for the bag-only type packaging as well.

Using the bag-in-box containers according to the invention as disclosed above enables the customer to dispense the enzyme, solution or dispersion from the container gradually, without the formation of headspace volume. This is a considerable advantage, since reactions in the headspace volume may cause microbial contamination or degradation by oxidation. By dispensing from a bag-in-box type container, the bag will simply collapse during emptying, and this can be achieved relatively easily without air entering the container. Thus, the amount of stabilizer and/or preservative as discussed above can be reduced or substantially omitted by dispensing the enzyme solution from the bag-in-box type container. By dispensing in that way, it may additionally be possible to have a pH value of the enzyme solution of more than 4.5.

Apart from adding stabilizers, preservatives and humectants another method employed up till now to improve the keeping qualities of enzyme solutions and dispersions over time was cooling/refrigeration. By using the aseptic bag-in-box or bag-only packaging method according to the present invention such refrigeration may be omitted, although for some purposes (depending on e.g. the enzyme involved and the time interval between opening and emptying the bag-in- box pack) a combination of bag-in-box packaging and refrigeration may still be employed. This may even strongly enhance the extension of shelf life, both before and after opening the packaging material. When using bag-in-box packaging, the bag, when filled with enzyme (solution) , may completely occupy all space available in the rigid box. For some purposes, however, it may be preferred that a smaller bag size is used without decreasing the outer dimensions of the box. This can be achieved by loosely packing e.g. a 25 litre bag or multiple 25 litre bags in a larger container. By doing so, the containers may be designed to be convenient for automated handling, including palletised stacking and transport, since they all have the same outside dimension and shape, whilst the amount of enzyme to be packed is flexible and can be adjusted according to the wishes of the customer or producer of the enzyme.

The invention is illustrated by the following examples but is in no way limited thereto.

In the examples the sterilized enzyme invertase, dissolved in water, without any additives was aseptically packed in four bag-in-box packs (size: 10 litres) . These bags were stored at room temperature for two months, and thereafter on subsequent days samples were taken from the packs. Two packs were stored at room temperature during sampling (samples 1 and 2) , and two were stored at ordinary refrigeration temperatures (about 4°C) during sampling (samples 3 and 4) . The samples were tested on TVC (Total Viable Count) , TE (Total Enterobacteria) , and Y + M (counts of yeast and moulds) . The results are set out in tables 1- 4. The results are also graphically displayed in figures 1 (samples 1 and 2) and 2 (samples 3 and 4) .

From the results it can be concluded that by using the bag- in-box type packaging method according to the invention the enzyme invertase could be kept in good microbial condition: - before opening for at least two months during storage at room temperature, and - once opened for at least 3 days when stored at room temperature, and at least 18 days when stored at low temperature after opening. When the same invertase solution was kept and distributed from an ordinary container, storage stability was shorter than 1 day after opening. From this it can be concluded that the shelf life of a packed enzyme solution once it is opened is extended dramatically by using bag-in-box type packaging, which then allows a reduced level of stabilizers and/or preservatives. These stabilisers and/or preservatives may even be omitted in certain cases.

Claims

1. Packed enzyme solution or dispersion contained in a bag type container or a bag-in-box type container, characterized in that the solution or dispersion comprises less than 30% by weight of stabilizer.

2. Packed enzyme solution or dispersion according to claim 1, characterized in that the solution or dispersion comprises less than 10% by weight of stabilizer.

3. Packed enzyme solution or dispersion according to claim 1-2, characterized in that substantially no stabilizer is present in the container.

4. Packed enzyme solution or dispersion contained in a bag type container or a bag-in-box type container, characterized in that substantially no -preservative is present in the container.

5. Packed enzyme solution or dispersion contained in a bag type container or a bag-in-box type container, characterized in that the pH value of the solution or dispersion is higher than 4.5.

6. Packed enzyme solution or dispersion according to claim 1-5, characterized in that the enzymes comprises a carbohydrate modifying enzyme.

7. Packed enzyme solution or dispersion according to claim 6, characterized in that the carbohydrate modifying enzyme comprises an enzyme having invertase activity.

8. Method for dispensing an enzyme solution or dispersion from a container characterized in that it is dispensed from a flexible container without the formation of headspace volume.

9. Method according to claim 8, characterized in that the enzyme solution or dispersion is dispensed from a bag- in-box type container.

10. A method according to claim 8-9, wherein the enzyme solution or dispersion is substantially free from stabilizers.

11. A method according to claim 8-10, wherein the enzyme solution or dispersion is substantially free from preservatives.

12. A method according to claim 8-11, characterized in that the pH value of the solution or dispersion is larger that 4.5.