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Patent Searching and Data


Title:
PRESERVATON OF VEGETABLES AND HERBS
Document Type and Number:
WIPO Patent Application WO/2003/055321
Kind Code:
A1
Abstract:
Shelf stable vegetable and/or herbs preparation containing a water soluble compound able to reduce the water activity to a value below about 0.65 and to increase the pH to a value of about 6.5 to 7.5 at ambient conditions.

Inventors:
Froelich, Markus (Altwiesenstr. 270, Zurich, CH-8051, CH)
Isler-sieber, Ernst (Langenmattstr. 6, Felben-Wellhausen, CH-8552, CH)
Penaloza Izurieta, Walter (In der Gandstr. 12, Zumikon, CH-8126, CH)
Application Number:
PCT/EP2002/014819
Publication Date:
July 10, 2003
Filing Date:
December 18, 2002
Export Citation:
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Assignee:
SOCIETE DES PRODUITS NESTLE S.A. (P.O. Box 353, Vevey, CH-1800, CH)
Froelich, Markus (Altwiesenstr. 270, Zurich, CH-8051, CH)
Isler-sieber, Ernst (Langenmattstr. 6, Felben-Wellhausen, CH-8552, CH)
Penaloza Izurieta, Walter (In der Gandstr. 12, Zumikon, CH-8126, CH)
International Classes:
A23B7/154; A23B7/157; A23B9/26; A23L19/00; A23L27/00; A23L27/10; (IPC1-7): A23B7/154
Foreign References:
US4832969A1989-05-23
US5858446A1999-01-12
EP0940090A11999-09-08
US4572836A1986-02-25
US5925395A1999-07-20
EP1010368A12000-06-21
GB2014429A1979-08-30
Attorney, Agent or Firm:
Wavre, Claude-alain (55 avenue Nestlé, Vevey, Vevey, CH-1800, CH)
Download PDF:
Claims:
CLAIMS
1. Shelf stable vegetable preparation characterized in that it contains a water soluble compound able to reduce the water activity to a value below or equal 0.65, preferably to a value of 0.6 to 0.65, and to increase the pH to a value of 6.5 to 7.5 at ambient conditions.
2. Shelf stable vegetable preparation according to claim 1, characterized in that the water soluble compound is an organic acid salt.
3. Shelf stable vegetable preparation according to claim 1, characterized in that the water soluble compound is selected from the group comprising acetate salts, ascorbate salts, aspartate salts, citrate salts, fumarate salts, malate salts, tartrate salts, succinate salts and lactate salts used alone or in combination.
4. Shelf stable vegetable preparation according to claim 1, characterized in that the water soluble compound is selected from the group comprising phospate salts.
5. Shelf stable vegetable preparation according to claim 1, characterized in that the water soluble compound is potassium or sodium acetate.
6. Shelf stable vegetable preparation according to claim 1, characterized in that the soluble compound used according to the present invention is combined with at least another Aw decreasing compound that is not an organic acid salt.
7. Shelf stable vegetable preparation according to claim 6, characterized in that the Aw decreasing compound is selected from the group comprising KC1 and NaCl used alone or in combination.
8. Shelf stable vegetable preparation according to claim 1, characterized in that it further comprises at least one humectant.
9. Shelf stable vegetable preparation according to claim 8, characterized in that the humectant is selected in the group comprising polyols and polydextrose.
10. Shelf stable vegetable preparation according to claim 8, characterized in that the humectant is selected from the group comprising reduced sugars.
11. Shelf stable vegetable preparation according to claim 8, characterized in that the humectant is selected from the group comprising glycerol and propan 1,2diol.
12. Use of a water soluble compound able to reduce the water activity to a value below or equal 0.65, preferably to a value of 0.6 to 0.65, and to increase the pH to a value of 6.5 to 7.5 for the shelf stabilisation and green colour preservation of vegetable preparations at ambient conditions.
13. Use according to claim 12, characterized in that the water soluble compound is an organic acid salt.
14. Use according to claim 12, characterized in that the water soluble compound is selected from the group comprising acetate salts, ascorbate salts, aspartate salts, citrate salts, fumarate salts, malate salts, tartrate salts, succinate salts and lactate salts used alone or in combination.
15. Use according to claim 12, characterized in that the water soluble compound is potassium or sodium acetate.
Description:
PRESERVATION OF VEGETABLES AND HERBS The present invention relates to vegetables and herbs and particularly to a method for the preservation of such foodstuffs.

Vegetables and herbs are widely used in processed-foods because of their taste and flavour properties. Besides the flavouring properties, vegetables and herbs are useful to impart a nice and pleasant coloured aspect to food products. Herbs are used in the preparation of numerous traditional dishes and the aroma and colour of various specific herbs are of great importance in these.

Thus, basil, olives, tomato, bell pepper, garlic, onion, carrot, coriander or mint, for example, do not only impart a pleasant typical flavour but also an attractive colour. Since herbs are seasonal and particularly sensitive to spoilage because of their high water content they are mainly found in dried form.

However, most herbs and vegetables when dried, lose their green colour. Aroma and flavour are also irreversibly altered so that they do not represent satisfactory alternative to freshly picked herbs.

The"freshness"is a universal quality issue with processed foods and this is of particular interest for herbs and vegetables because such products inherently refer to freshness. Regarding herbs, the green colour aspect is considered as a key factor for assessment of this freshness and because of all the processes that

herbs may be subjected to, the green colour is quite often adversely affected.

The chemical basis for the loss of bright green colour of fresh vegetables and herbs has been extensively studied. Thus, chlorophyll, which is responsible for this bright green colour degrades during thermal processings such as drying, for example. However, in non heat-treated food products, the green colour is also dictated by the chemical stability of the chlorophyll which has been shown to be acid sensitive and to have its maximal stability and therefore its maximal green colour aspect at pH of about 7 and slightly above.

In the particular case of culinary applications, herbs and/or vegetables are intimately mixed or ground.

Mixing or grounding even accelerate spoilage. The product can therefore not be stored for a long time without any preservatives.

The microbial stabilization may be achieved by lowering the pH by addition of acids and/or lowering the water activity (Aw) thanks to addition of salts as well as addition of anti-microbial additives like sulphites or sorbate for example.

The dehydrated products have a typical Aw of about 0.2 to 0.3 and are therefore microbiologically stable since no organisms can grow at Aw below about 0.6 to 0.65. At Aw higher than about 0.6 to 0.65, microbial growth can occur causing spoilage, formation of off-odours as well

as infection with pathogenic microorganisms and/or toxins. Since the perception of freshness in ambient stable products may be obtained at Aw of about 0.6 to 0.65, the prevention of microbial growth may be achieved by addition of preservatives and/or reduction of pH.

But, as said before, chlorophyll is not stable anymore and therefore the green colour disappears at acidic pH.

Some attempts have been made to obtain shelf stable vegetables or herbs with improved colour.

WO 9607334 relates to fresh herbs with bright and fresh colour that can be used for culinary applications and that can be stored for protracted periods. It is taught that the leaves of aromatic plants are mixed in the absence of oxygen with either a salt and/or an oxygen scavenging agent in order to obtain a water activity of the mixture below 0.9.

EP 87717 discloses a dried vegetable product manufacturing process in which a plant is stabilised by heating and addition of electrolyte before drying with a carrier.

US 4832969 discloses dried green vegetables with superior colour retention. The manufacture of such dried vegetables comprises the steps of blanching the

pieces of vegetables in a bath having a pH of about 7 to 9, infusing the blanched vegetable pieces in a solution comprising sugar alcohol, sugar and bittering agents such KC1 or MgCl2 and finally drying the vegetable pieces to an Aw of 0.3 to 0.85.

All these prior art technologies are complicated and involve the use of various chemical preservatives that are not always well perceived by the consumer.

Moreover, these prior technologies refers to dried products that do not bring the freshness to the consumer.

Therefore, there remains a need for shelf stable herbs or vegetables preparations that exhibit a bright and attractive green colour.

Accordingly the present invention provides a shelf stable vegetable preparation characterized in that it contains a water soluble compound able to reduce the water activity to a value below or equal about 0.65, preferably to a value of about 0.6 to 0.65, and to increase the pH to a value of about 6.5 to 7.5 at ambient conditions.

A further object of the present invention also concerns the use of a water soluble compound able to reduce the water activity to a value below or equal about 0.65, preferably to a value of about 0.6 to 0.65, and to

increase the pH to a value of about 6.5 to 7.5 for the shelf stabilisation and green colour preservation of vegetable preparations at ambient conditions.

In the present description, the term"vegetable preparation"refers to any edible foodstuff made from vegetable either in pieces, in purée, minced or chopped. Vegetable in pieces may either refer to vegetable of small size in its integrity or vegetables which have been cut to a size suitable for food industry.

The term"vegetable"herein refers to any plant material used in food industry. As plant material, one may cite either leaves, roots, fruits, stalk or seeds for example. Vegetables that may be concerned by the present invention may be herbs like basil, coriander, oregano, tarragon, mint, parsley, chives, aneth, as well as other aromatic and non aromatic vegetable like bell peppers, broccoli, lettuce, peas, zucchini, celery, and the like.

The expression"ambient conditions"refers to the ambient temperature and pressure values, namely about 10-30°C, preferably 15-25°C, typically about 20°C, and atmospheric pressure, typically about 1 bar.

It has surprisingly been found that the addition of a single water soluble compound in suitable amount to the

vegetable preparation allows in the same time to reduce the Aw as well as adjust the pH to a value compatible with chlorophyll stability, namely around 7.

According to our knowledge it is the very first time the use of a single water soluble compound for both decreasing the Aw and adjusting the pH at a value of about 6.5 to 7.5 in order to stabilise and preserve the green colour of vegetable preparation is disclosed.

Thus, thanks to the ability of the soluble compound to reduce the Aw to a value below or equal about 0.65, preferably to a value of about 0.6 to 0.65, the shelf stability of the vegetable preparation according to the invention is obtained without the use of any additional preservatives.

The suitable water soluble compound for the manufacture of the vegetable preparation according to the present invention may be any food acceptable organic acid which behaves as a base when deprotonated, namely when present in the salt form. Suitable organic acids salts may be selected from the group comprising acetate salts, ascorbate salts, aspartate salts, citrate salts, fumarate salts, malate salts, tartrate salts, succinate salts and lactate salts as well as phosphate salts and carbonate or bicarbonate salts used alone or in combination. The present invention being based on the finding that a single organic acid can, in the same time, reduce aw as well as adjust the pH, a combination

of several suitable organic acids salts may also be envisaged.

The organic acids salts suitable for the vegetable preparation according to the invention may be potassium or sodium salts, for example.

According to a preferred embodiment of the present invention the soluble compound is an acetate salt such as potassium acetate. Indeed, potassium acetate at saturation level can reduce the Aw to 0.23 at 20°C.

Acetic acid shows a pKa value of about 4.5 and thus behave as a soft base above this value. The deprotonated acetate salt in solution exhibits a pH value of up to about 6.5 to 9.

If desired the soluble compound used according to the present invention may be combined with another Aw decreasing compounds like electrolytes such as NaCl or KC1 for example or polyols such as glycerol for example.

The vegetable preparation according to the present invention does not need any extra heat treatment for stabilisation. The vegetable preparation according to the present invention presents a flavour and aroma profile quite identical to a fresh one. In the case of herbs preparation, it exhibits not only the freshness, the full aroma and flavour of the freshly prepared picked herbs but also the typical bright green colour of such products.

The vegetable preparation may be in the form of minced leaves of herbs that can be used upon need for the aromatisation of meal or the preparation of dishes necessitating the aroma and flavour of fresh herbs.

The vegetable preparation according to the present invention may be used in any type of food products provided that the Aw is not disturbed. The vegetable preparation according to the present invention may thus be included in culinary preparation such as bouillon tablets, cooking aid tablets, dehydrated bouillon, soups or sauces but also in cooking aid in the form of tablets for example. A particularly interesting application of the vegetable preparation according to the present invention concerns the cooking aid as exposed in the Patent application WO 01/72148.

The vegetable preparation according to the present invention may also be used as such, or as a separately packed ingredient for soups, or as an ingredient for frozen preparations such as frozen vegetable mixtures.

The preparation according to the present invention may also be comprised in spoonable and portionable products comprising minced or chopped fresh herbs ready for dispensing whether into a meal or a plate. However, for such applications, since the preparation should be contained in a container to be opened several times, there may be a risk of cristallisation of organic salts

that would be detrimental to consumer acceptance and convenience. Accordingly, in order to prevent dehydration of the preparation and the subsequent cristallisation of organic acid salts as well as to ensure its easy portionability, the preparation according to the present invention may comprise at least one humectant selected in the group comprising polyols, and polydextrose. Polyols may be selected from the group comprising reduced sugars. Suitable reduced sugars may preferably be selected in the group comprising sorbitol or manitol. Suitable polyols may be selected in the group comprising glycerol or Propan- 1, 2-diol for example. Indeed, the addition of glycerol, for example, prevents from dehydration and therefore permits to obtain a spoonable and easily portionable product in which organic acid salts remain non cristalized, and of course keep a fresh, brilliant and attractive appearance. The quantity of polyol may range from 1% to 60%, preferably from about 10 % to 40% based on the total weight of the preparation according to the invention.

The vegetable preparation according to the present invention is shelf stable at ambient or room temperature and keeps the typical green colour all along the storage time at ambient or room temperature providing that the pH does not fall below about 6.5 to 7.5 because the chlorophyll would go on degradation and the green colour would then disappear.

EXAMPLE FRESH GREEN HERBS AND ONION PUREE The following ingredients (% in weight) are added in a tank with a cutter and a stirrer thermostated at 25°C : NaCl 31% Potassium acetate 13% Sodium Glutamate 11% Modified starch 0.4% Onion purée 27% Basil 6.6% Water 11% The onion puree consists of pasteurized finely ground onions.

Basil consists of fresh basil leaves washed and drained.

The whole mixture is mixed for 10 minutes and filled in pots. It exhibits the typical aroma of basil and onion and the basil leave particles show the fresh bright green colour similar to fresh leaves.

The Aw of the basil/onion puree is 0. 65 and the pH is 7.26. This preparation may be kept at ambient temperature for seven months without any substantial loss of aroma or modification of colour.