WO2007026176A2

WO2007026176A2 - Condiment

Info

Publication number: WO2007026176A2
Application number: PCT/GB2006/003271
Authority: WO
Inventors: Charles Michael Byrne; Philip Evelyn Douglas; Aldo Tocin; Geoffrey William Steinicke; Jonathan David Mitton
Original assignee: Ringfort Patents Limited
Priority date: 2005-09-02
Filing date: 2006-09-04
Publication date: 2007-03-08
Also published as: WO2007026176A3

Abstract

A food and flavouring additive is a fermented product obtainable by fermentation of the waste water from an olive oil mill.

Description

Condiment Field of the Invention

This invention relates to a condiment, and to the use of the olive oil mill wastewater (katsigaro in Greek, alpechfn in Spanish and acqua di vegetazione in Italian) which is generated as a waste product in the manufacture of olive oil. Background of the Invention

There are three basic methods for the production of olive oil, I.e. the batch press, the three-phase, and the two-phase methods. Each generates olive oil mill wastewater, abbreviated herein as OMW.

In the batch press method, the production of olive oil involves milling the whole olives, and pressing the resultant slurry (malaxa in Greek, pasta de malaxaciόn in Spanish) to separate the solid portion from the liquid portion.

The liquid portion is composed of oil and water. The oil is then separated from the aqueous portion by sedimentation and centrifugation techniques.

In the two- and three-phase methods, the water and solids together are separated from the oil by centrifugation, water having been added in the three-phase process. In these methods, the water from the olives is mixed with the solids (with the added water, in the case of the three-phase method), the mixture being called alperujo in Spanish.

The commercial production of olive oil by mechanical extraction is efficient but requires the addition of water for the process to run smoothly.

While not necessarily detracting from the ability to produce desirable grades of olive oil such as extra virgin olive oil, there is some loss of quality by comparison with pressed product.

The OMW that is generated by the batch press method, and which can be extracted from the alperujo generated by the other two methods, is traditionally discarded. It contains some oil, some suspended solid material and some soluble solids. Its composition (by dry weight, except dry matter and pH; see Paredes et al (1999), Bioresource Technology 67(2): 111-115) is given in Table 1. Table 1

The disposal of OMW constitutes a large and increasing cost to industrial producers of olive oil and, in those places where it is not treated, it constitutes a source of damage to the environment. Spreading OMW on agricultural soil should be avoided, although it is a cheap form of water, as it is harmful to plants and soil.

The use of fermentation technology to reduce the environmental impact and cost of this material has been studied. Its use in the production of a fertiliser is described by Piperidou et al (2000), Journal of Agricultural and Food Chemistry 48(5): 1941 -1948.

The Greek method for production of naturally black table olives involves a fermentative stage, as described by Brenes (2004), Journal of Food Science 69(1): M33-M34. The olives are left in a brine solution for a period, and the flavour of the olives changes due to leaching out of compounds as well as microbiological action. The microflora found on the olives includes inocula that are capable of modifying the flavour of the olives by acidification and by a reduction in bitterness compounds. Starter cultures are introduced to give the best initial inoculum; see Comi et al (2000), Industrie Alimentari 39(397): 1258-1265.

During the fermentation stage, there is a rise in the number of yeasts and lactic acid bacteria (LABs), and a decrease in the number of pseudomonads and enterobacteriaceae after an initial increase. The LABs in particular are responsible for the conversion of carbohydrate material found in the fruit into acids, mostly lactic acid; see Tassou et al (2002), Food Microbiology 19(6): 605-615. This change is crucial in the production of table olives, increasing the shelf-life of the product, and altering the flavour.

Another result of the fermentation is the reduction of bittering compounds, such as the polyphenol^ compound oleuropein which is digested by the enzymes produced by some LABs; see Piperno et a/ (2004), Sci. Food Agric. 84(4): 341-349, and Ciafardini et a/ (1994), Applied and Environmental Microbiology 60(11): 4142-4147. Other polyphenol^ compounds are responsible for such flavour attributes as astringency and pungency; see Andrewes et al (2003), Journal of Agricultural and Food Chemistry 51(5): 1415-1420. The control of these compounds is therefore important for the flavour profile of table olives. Summary of the Invention

The present invention derives from the discovery that OMW can be modified by a fermentative process to produce a palatable liquor. Although this invention relates in one aspect to the fermentation of OMW to manufacture a food product, the same process may be used to other oil wastewaters such as those obtained from walnut, avocado etc.

Without wishing to be bound by theory, it appears that, during fermentation, several changes take place, including the conversion of sugars into acids and the reduction of bitterness and astringency. Thus, fermentation changes what is an undesirable waste product into a marketable food product which is not only delicious, but also a functional food insofar as it is very high in desirable polyphenols/antioxidants.

This invention provides a condiment obtainable by the natural fermentation of the wastewater from olive oil mills. By a modification of the fermentation processes traditionally and currently used in the manufacture of Greek table olives, the OMW is converted into a condiment with a pleasant taste and aroma of olives. The product can be derived entirely from this raw material, or with the addition of other flavouring ingredients, such as garlic, herbs, pepper, anchovy etc., which can be added in various forms at various stages of the process. The product can be aged to alter its flavour profile. The product can be concentrated to give a desired flavour profile, or to give a product with the consistency of a paste or powder.

According to a further aspect of the present invention, in the production of olive oil, the known step of introducing water for process efficiency is replaced by the addition of OMW. In order to inhibit the propensity of the OMW to naturally ferment and thus adversely affect the quality of the resultant olive oil, suitable pre-treatment of the OMW may be necessary. Such pre- treatment may be chilling thorough a heat exchanger, pasteurisation, an addition of salt and/or carbohydrate, an inoculation with micro-organisms that will remove oxygen from the OMW, and/or the storage of the OMW under conditions that ensure it does not damage the oil being produced.

This simple step can have various advantages. Firstly, the loss of quality observed in mechanical extraction can be avoided. Secondly, the content of non-oil components such as anti-oxidants and polyphenols may be improved. There is a desirable environmental effect, as a large amount of fresh water could be saved in olive-producing areas which are often short of water as a natural resource.

Description of Preferred Embodiments

For use in the invention, OMW is typically collected from a mill. It can be processed at this stage to achieve one or more of several objectives: (1) concentration, e.g. by evaporation, to enhance the flavour profile of the final product and reduce the fermentation space required; (2) solids removal by filtration or centrifugation or a combination of these techniques, to improve consistency and fermentation control; and (3) microbiological improvement by pasteurisation, boiling, UV treatment or other techniques, or a combination thereof. This may facilitate the concentration stage.

Salt, sugar, and any other desired ingredient may be added to the OMW. The presence of salt, e.g. at a level of 5% w/v, can inhibit immediate fermentation. An inoculation of suitable micro-organisms may also be added at this stage. The OMW to be treated may have been diluted during the process of oil separation.

The OMW may be fermented by known means. For example, it may be introduced into a fermentation vessel where it is inoculated with any starter culture as required.

In an embodiment of the present invention, OMW is put into a fermentation vessel with appropriate levels of any of nutrient, salt and sugar being added, and allowed to ferment for a period of time. For example, the OMW is put into a fermentation vessel with appropriate levels of salt and sugar as well as other ingredients which can be added as a crushed mass, a liquid or an extract; examples of such ingredients are fruit, herbs or other plant material. OMW may be derived from the separation of oil from a mash of crushed olives, the olives having been previously mixed with other plant materials to flavour the oil, such as fruit or herbs.

During the fermentation, various parameters may be monitored, in order to achieve the desired fermentation characteristics, such as temperature, pH, carbohydrate and salt concentration. The microbiology of the ferment may also be monitored, and starter cultures can be added during the fermentation. The change in flavour of the product is preferably monitored, and the fermentation stage is considered to be finished when a desired flavour has been achieved.

After fermentation, the product is typically filtered, pasteurised and packaged as required. It may be stored in casks or other vessels for conditioning before being filtered, pasteurised and packaged as required.

The fermented liquor may be concentrated after the fermentation stage, either before or after being filtered and pasteurised. Concentration may be by reverse osmosis, freeze-concentration or by an evaporative method. The degree of concentration may be slight, just to change the flavour profile, or relatively large, to produce a product with a high viscosity. Concentration can be used to produce a paste or powder.

The process of olive fermentation (as described in the Background of the Invention) relies on carbohydrates and polyphenols diffusing out of the fruit and acids diffusing in. The changes in the properties of the olives are mediated by changes occurring in the brine environment in which they are stored.

This invention relies on the same fermentation process occurring in a liquid medium, the OMW, which is composed of the aqueous content of the fruit. The carbohydrate in this liquid is consumed by microflora which produce acids and reduce the polyphenols. The liquid loses its bitterness, astringency and pungency to the desired level and becomes palatable, and the increased acidity gives it a long shelf-life. At this stage, it is possible to package a finished product, typically after suitable filtration and pasteurisation. A preservative or mould-inhibiting agent such as potassium sorbate, may be added if required, with or without previous pasteurisation.

Packaging may be simply in a bottle or other container having a removable closure, for ready use, e.g. in the flavouring of food. The product has a long shelf-life, e.g. due to the presence of the salt and the low pH. Other flavouring may be added, before such treatment.

Alternatively or in addition, other processes may be adopted at this stage. For example, concentration processes such as reverse osmosis, freeze-concentration or evaporation may be used, to achieve a desired flavour profile; further concentration may be used to achieve a consistency anywhere between that of a thin paste to that of a solid. There may also be further storage in casks or other suitable vessels with or without other flavouring additions. When the "further aspect" of the invention (described above) is used, it can be carried out in known manner, using known apparatus and known technology, apart from the substitution of water by OMW. The skilled person will readily be able to understand how the invention can be conducted, using available material.

The following Examples illustrate the invention. Example 1

1000 litres of OMW was collected from a press style olive oil mill. It was left in a stainless steel vessel after the addition of 2.5 g/L sucrose and

50 g/L salt, for a period of six months at ambient temperature (15 to 35⁰C).

The OMW had a sufficient layer of oil on top to ensure anaerobic conditions during the fermentation.

The flavour profile of the product was assessed, and deemed to be very good. Example 2

50 litres of OMW was collected from a traditional press style mill and put into a vessel with the addition of 2.5 g/L sucrose and 50 g/L salt. The vessel was sealed with an airlock, which allowed gases produced to escape, but no oxygen to enter.

The vessel was held at ambient temperature (7 to 15°C) for a period of six months before being decanted into smaller vessels. After a further conditioning period at 30⁰C for a month, the product was analysed.

The pH was 4.2, no fermentable sugars were detected, and no pseudomonads of enterobacteriaciae were found. The flavour of the product was clean, with a clean, strong flavour of good table olives. Example 3

50 litres of OMW was collected from a traditional mill and put into a vessel with the addition of 250 mL lemon juice and 50 g/L salt. The vessel was sealed with an airlock, which allowed gases produced to escape, but no oxygen to enter.

The vessel was held at ambient temperature (7 to 15⁰C) for a period of six months before being decanted into smaller vessels. After a further conditioning period at 3O⁰C for a period of a month, the product was analysed. The pH was 3.5, no fermentable sugars were detected, and no pseudomonads or enterobacteriaciae were found. The flavour of the product was clean, with a clean, strong flavour of good table olives with a background of lemon.

Claims

1. A fermented product obtainable by fermentation of the waste water from an olive oil mill.

2. A container having a removable closure and containing a product according to claim 1.

3. A process for the production of a product according to claim 1 , which comprises subjecting the waste water from an oil mill to fermentation in a fermentation vessel.

4. A process according to claim 3, wherein the fermentation liquor additionally comprises one or more of nutrients, salt and sugar.

5. A process according to claim 3 or claim 4, which additionally comprises concentrating the fermentation liquor and/or the fermented liquor.

6. A process according to any of claims 3 to 5, which additionally comprises filtering the fermented liquor.

7. A process according to any of claims 3 to 6, which additionally comprises pasteurising the fermentation liquor and/or the fermented liquor.

8. A method of flavouring food, which comprises adding thereto a product according to claim 1.

9. A process for the production of olive oil by pressing, which comprises adding waste water from an olive oil mill, prior to separating the solid and liquid portions.