NZ280652A - Non-acid herb product stored unfrozen in an oxygen-free atmosphere at +8 to -20<degree>c - Google Patents

Description

New Zealand Paient Spedficaiion for Paient Number £80652 New Zealand No. International No. 280652 PCT/ TO BE ENTERED AFTER ACCEPTANCE AND PUBLICATION Priority dates: 11.12.1995 Complete Specification Filed: 11.12.1995 Classification:^) A23L1/22.223; A23L3/3418,3436 Publication date: 24 November 1997 Journal No.: 1422 Title of Invention: Processed fresh herbs Name, address and nationality of applicant(s) as in international application form: BYRON AGRICULTURAL COMPANY PTY LTD, an Australian company of 19A Boundary Street, Rushcutters Bay, New South Wales 2011, Australia NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION 280 6 5 2 NEW ZEALAND PATENTS ACT, 2953 No: Date: COMPLETE SPECIFICATION PROCESSED FRESH HERBS We, BYRON AGRICULTURAL COMPANY PTY LTD, an Australian company, of 19A Boundary Street, Rushcutters Bay, New South Wales 2011, Australia, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: (Followed by page la) 280 6 5 2.

PROCESSED FRESH HERBS BACKGROUND OF THE INVENTION Culinary herbs together with aromatic plants such as ginger, garlic, peppers and 5 chillies are much prized ingredients in cooking. Fresh herbs are cultivated in home and commercial gardens and today are available fresh in many varieties. 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.

In most parts of the world, fresh herbs are seasonal. Herbs may be obtained year 10 round in dried form. Most herbs when dried, however, lose their green colour, aroma and flavour and are irreversibly altered so that they do not represent a satisfactory alternative to freshly picked herbs.

Many of the popularly used herbs contain enzymes which act very rapidly when the cell structure of the herb is disturbed resulting in loss of green colour, production 15 of dark pigments and both loss of fresh flavour and the development of off-flavours. These changes occur more rapidly at elevated temperatures such as occur in many food processing operations and in cooking. Amongst these herbs are basil, coriander (cilantro), oregano, tarragon and mint Many studies have been made on the enzymic degradation of herbs including those by Baritaux et al, 1991 (Sciences-des-aliments 11, 20 (1) 49-62), Gerherdt. V et al (Fleischerei 34 (5) 508-208). Studies have also been made on the drying and storage stability of dried herbs, including those by Mastrocola, D et al 1988 (Industrie-Alimentari 27 (259) 341), Paeaekkoenen, K et al 1990 (J Food Science 55 (5) 1373-1377).

Many herbs can be obtained nowadays in frozen and freeze-dried form. Frozen 25 herbs have good flavour and colour, but must be kept frozen and when thawed or used in cooking and in processed products are subject to the same enzymic action and colour and flavour changes as fresh herbs. Freeze-dried herbs, which are expensive to produce when wetted, suffer from the same enzyme action as frozen herbs.

The enzyme action in herbs can be prevented by blanching of the herbs in steam 30 or hot water. In this way, the green colour can be largely preserved but often almost completely destroyed. Ricci in British Patent No. 1 342 fj < describes production of a green food flavouring by heating basil leaves ia hot water, 2806 52 a » quenching in cold water, cutting into pieces and refrigerating.

Herbs, along with other vegetables, for many ages have been traditionally preserved by pickling with salt or salt brine with or without vinegar. This method is used extensively in the pickle industry. Herbs treated in this way lose their attractive 5 bright green colour and much of the flavour is lost into the brine. Unless pasteurised these products are subject to surface molds and to salt and sugar tolerant yeasts. Coste (British patent 2,014,429,1979) claims to have preserved chopped herbs by mixing with water activity controlling substances such as salt, glycerol and propylene glycol in such concentration that the water activity is less than 0.90. Oil up to 20% may be added to 10 give a pasty consistency. We have observed that in following the procedures described by Coste, the resultant herb mixes quickly developed a dark olive green colour. In the case of the herbs with high levels of polyphenol oxidase enzymes such as basil mint and oregano the colour that developed on storage was a dark greenish black. In all cases, the colour changes were accompanied by off-flavours. Moreover, it was observed that 15 even at water activities of 0.80, yeast and mold growth could occur on the surface of the mixes.

OBJECTS OF THE PRESENT INVENTION Throughout this specification, the term "herbs" refers to the leaves, flowers, barks, fruits, roots or other aromatic parts of plants normally used for culinary purposes. 20 An object of the present invention is to produce a herb product with a natural bright fresh colour and a fresh flavour that is convenient to use for culinary purposes and which can be stored and distributed on a year round basis.

A farther object of the present invention is to produce food products containing fresh herbs which are stored at refrigeration or freezer temperatures in a form suitable 25 for convenient use that retain to a large extent both the colour and the flavour of the fresh herbs and can be used by the consumer to impart to culinary products such as sauces, dressings, casseroles, soups and other dishes the fresh flavour and colour of those herbs.

A further object of the invention is to produce food products containing fresh 30 herbs which may be suitably stored and distributed so that the aforementioned products and qualities can be available on a year-round basis.

A still further object of the invention is to produce herb proriKjpts which ' OS IB 11 j '"y 2806 52 adaptable to packaging in a range of quantities which vary from bulk industrial, smaller food service and retail unit size packs without any variation in quality in relation to the material used for such packaging.

A still further object of the invention is to produce herb products which when S held at near freezer or freezer temperature are sufficiently soft and fluid that they can be used directly from the freezer without thawing.

A still further object is to produce a herb product that may be pasteurised and suitably packaged to produce a product for use where pasteurised herbs are needed. SUMMARY OF THE INVENTION 10 The invention according to a preferred form relates to a herb product comprising the leaves, flowers, barks, fruits or other aromatic parts of plants normally used for culinary purposes which have been intimately mixed: (a) in the absence of oxygen with either a salt or mixture of salts or an oxygen scavenging agent or a mixture thereof together with such concentrations of water activity controlling solutes that the water activity of the mix is 0.90 or lower, or (b) in the presence of oxygen with an oxygen scavenging agent with or without a salt or mixture of salts together with such concentrations or water activity controlling solutes that the water activity of the mix is 0.90 or lower the resultant product being stored in an oxygen free or substantially oxygen free atmosphere and remaining unfrozen at temperatures within the range of 8°C to -20°C.

The mixing may be performed in the presence of air in an open mixer 25 provided an oxygen scavenger is included in the mix.

The salt is preferably sodium chloride, but other salts such as potassium chloride, calcium chloride, sodium citrate, sodium lactate and other edible salts can be used. The oxygen scavenger or antioxidant preferably comprises ascorbic acid or its salts, erythorbic acid or its salts or related compounds. Water activity controlling substances 30 may be salts such as sodium chloride, sugars, polyhydric alcohols, protein hyrolysates, hydrolysed starches. Also present may be pH controlling substances such aS socfiiiht citrate and citric acid, emulsifiers, vegetable oils, flavourings, essential oils and %/ .O 2806 52 oleoresins, stabilisers such as gums and other food ingredients such as cheese, meats, preservatives, flavour potentiators and the like.

The invention also consists of food products containing said herb product. PREFERRED EMBODIMENT 5 In preparing these stable herb products, the herbs should be freshly picked, well washed and kept cool. Succulent stems may be included with the leaves. Prepared quick-frozen herbs may also be used. With fresh herbs, after washing, excess water is removed, for example by blowing with an air steam or by centrifuging. The herbs may then be reduced to particles of predetermined size for example by pulverising or 10 chopping in a cutter, slicer or dicer such as is common in the food industry. Some small leafed herbs for instance thyme leaves, may be used in unchopped form. Throughout the process the herbs are preferably to be kept as cool as possible. The chopped or otherwise prepared herbs are then mixed with as iittie delay as possible with the salt or salts, the oxygen scavenger and the water activity controlling solutes. If a 15 high enough concentration of salt is used, this may be sufficient to control the water activity to 0.90 or below, without the use of additional water activity controlling substances. Other food ingredients such as vegetable oil may also be added at this stage. Alternately, the mixture of whole or coarsely cut herbs and other ingredients may be chopped together in a single operation to any degree of comminution using suitable 20 equipment such as a food processor with rotating sharpened blades equipped for operation under vacuum or inert gas. One typical piece of industrial equipment of this type is manufactured by the Stephan Co., Hameln, Germany.

The mixing or combined mixing and chopping operation are preferably performed under conditions which subject the ingredients to as little oxygen as possible. 25 This is best achieved either in an inert gas such as nitrogen or under vacuum. It can, however be performed in an open mixer provided the oxygen scavenger is added. In this case the mixture should preferably be vacuum de-aerated after mixing During mixing, the solutes dissolve in water extracted from the herbs and form a flowable liquid mix. It is therefore usually unnecessary to add any water. 30 After mixing, the herb mix is packaged in sealed glass jars or other lovro? transmission packages such as flexible laminates, metal or plastic tubes, ,6tc. In smalle^ * '* y containers for consumer use it is preferred that the type of package be such that the ~, ^ "I 2806 52 contents can be squeezed out and re-sealed (eg a metal tube) so that air is kept to a minimum within the package. The packaged product is held at low temperature, preferably between 8°C and -20°C and more preferably at -20°C.

The herb products prepared as outlined above may be pasteurised in a heat 5 exchanger in the absence of oxygen and either cooled and aseptically packaged or packed hot into low oxygen transmission containers and rapidly cooled after the package is sealed. Such pasteurised packs have good colour retention and flavour though not as good as the unheated products. They may be used where a pasteurised product is need, for example for addition to dairy products.

The herbs may be selected from any of those customarily used for human consumption. Included amongst the herbs used in accordance with the present invention are basil, coriander (cilantro), oregano, tarragon, mint, parsley, chives and chervil and other aromatic plants such as red peppers, chillies, garlic and ginger (collectively herein referred to as herbs). The present invention relates to products in which the colour of 15 culinary herbs together with their fresh flavour can be retained for an extended period of time. While all herbs will benefit from this invention, those herbs which contain particularly active enzyme systems which lead to rapid colour deterioration and associated flavour changes benefit to an even greater degree.

The present invention relates not only to herbs such as basil, oregano, coriander, 20 tarragon and mint which oxidise very quickly but is also equally beneficial for other herbs such as parsley, chives, garlic and ginger.

It has been found that by processing of these herbs as described herein, a very superior product can be prepared: 1. Incorporating edible salts such as sodium chloride or potassium chloride 25 assist in preventing the rapid discolouration and flavour change of the herbs. While a salt concentration as low as 3% retards discolouration a salt level as high as 20% has a more pronounced and lasting effect on maintaining colour and flavour. Since these herb preparations are used at a low level in the recipe as consumed, for instance about 2 to 5%, Jhe. salt can-percent. salt carry-over into the dish is low, usually not more than one half of one > o] When the mixing procedure is not performed under insert gas or vac\ggn^j^ ■951211 pj^n 280652 € 1 * or when a salt is not added, the addition of ascorbic acid, sodium ascorbate, erythorbic acid or other similar antioxidants with the herbs achieves colour and flavour retention. The level of the antioxidant used would normally be below 2%, most usually between 0.2 and 1.0%. Even when mixing is performed in the substantial absence of oxygen, the use of the oxygen scavenger is often advantageous. 3. To achieve prolonged maintenance of colour and flavour, the mixture of herbs, salt and the antioxidant must be protected from oxidation by packaging so that minimal exposure to oxygen can occur. This may be achieved by packaging in sealed containers of glass or metal, or in flexible packages with low oxygen permeability.

Since the herb mix is packaged under anaerobic conditions, to avoid spoilage it must be maintained at a water activity below 0.90, preferably below 0.85. This may be achieved by maintaining a sufficiently Hgh level of sodium chloride (10-20%) or by adding to the mixture other water activity controlling solutes such as sugars, polyhydric alcohols or other salts. Where sugar additions are used to control the water activity, those sugars with a low sweetness level such as lactose, dextrose and maltose are preferred.

The mixture, to ensure good shelf-life should be kept cool below 8°C and preferably under freezer conditions (about -20°C). The choice of salt concentration and that of other water activity controlling solutes can be made so that even at -20°C, the mixture will maintain its fluidity, will not freeze, and can be used directly out of the freezer without thawing. It has been found that if the herb mix has a water activity of about 0.90 or less, ice crystals will not usually develop in the product and fluidity will be maintained. Herb mixes prepared as outlined above will maintain their fresh colour and flavour for in excess of twelve months.

The herb preparations prepared as described above may be used in die preparation of a range of herb-based sauces which are preferably prepared without heating at water activities about 0.85. These sauces are packed in packages with minimal exposure to oxygen and are preferably stored at freezer temperature for lo ' v'/ shelf-life. If a combination of salt and/or other water activity controlling solutes areo used to arrive at a water activity about 0.85, the products remain fluid or spoonable at Vo Y E 0 ^ T'lTl l|i'm| 1 i I'IIIiiII' i| iiTWll >in II 280 6 52 freezer temperatures. In the preparation of these sauces, it is often desirable to add a proportion of up to about 50% of an edible oil. The oil generally improves the flow characteristics of the product, partially dissolves and assists in stabilizing the essential herb oils and assists in the blending of these flavours in culinary preparations. It is 5 preferred to use an oil which does not solidify at freezer temperatures. One such oil is sunflower seed oil, but other oils such as safflower and corn oil have also been found suitable. In preparing sauces with edible oils, the use of emulsifying agents such a polyoxyethylene sorbitan esters of fatty acids, monoglycerides, lecithin and sugar esters may be found necessary.

These herb preparations and herb based sauces may be used on cooked pasta, rice or vegetables, in salad dressings, in other recipes where a fresh herb flavour or colour is desired, in cottage cheese mixes and many other prepared foods.

The invention will now be described with reference to the following non-limiting examples. 1. BASIL Fresh basil leaves were washed and chopped in a kitchen type food processor with the ingredients listed below for about 60 seconds or until the size of the leaf 20 particles was about 1.5 x 1.5mm. % by weight Basil leaves 70.7 Salt 14.0 Dextrose 14.0 Citric Acid 0.3 Guar gum 0.3 Sodium erythorbate 0.7 The resultant paste was transferred to a container and placed in a vacuum 30 chamber which was evacuated several times to remove entrapped air. The basil paste had a water activity of 0.80. It was packed into low-oxygen-trajj^mi8^Jrf fcLea laminated pouches holding about 150g each.

IpMwpdow^ 280 6 52 These were sealed to eliminate as much air as possible. Some of the packs were stored at -20°C, others at 6°C. After 4 weeks the basil stored at 6°C was just a darker than that stored at -20°C. After 4 months it was noticeably darker but still a bright green. The product at -20°C was equally as bright as when first made and had 5 a typical fresh basil flavour. 2. TARRAGON Fresh washed tarragon leaves were chopped in a kitchen food processor which had been fitted with a plastic sleeve on the top opening so that nitrogen gas could be 10 flowed through the processor during chopping. The leaves were chopped for about 60 seconds with the following ingredients: % by weight Tarragon leaves 50.7 Emulsifier (sugar ester) 0.3 Salt 10.0 Lactose 11 Dextrose 11 Safflower oil 16.7 Guar gum 0.3 The product had a water activity of 0.86. The viscous emulsion was packed into aluminium tubes and the ends sealed. The tubes were stored at -20°C. For use, the screw cap was removed from the tube and a quantity of the emulsion squeezed out Even though stored at -20°C, the product was still fluid. After use, the tube was 25 resealed with the cap so that a negligible quantity of air was entrapped. After twelve months, the colour and flavour of the tarragon had not changed. 3. GARLIC Garlic cloves were peeled of their outer membranes and chopf food processor for 2 minutes with the following ingredients: <"> 9S!3Hp'WpdeM'iri^Vipp,5802 2806 5 2 % by weight Garlic 70.5 Salt 9.5 Whey powder 9.5 Ascorbic acid 0.2 Citric acid 0.3 Sunflower oil 10.0 The resultant paste had a water activity of 0.84. It was packed into plastic tubes which 10 had been made from an opaque laminate containing aluminium foil as an oxygen barrier. These were stored under refrigeration at 6°C. After 12 months the creamy white colour of the paste had not deteriorated and the flavour was typical of fresh garlic. 4. PESTO with BASIL A pesto sauce was prepared from fresh basil leaves by chopping all of the following ingredients together in a Stephan UMC Cutter (A Stephan U Sohne, Hameln, Germany) equipped for vacuum cutting and mixing. % by weight Basil leaves 29.1 Citric acid 0.2 Salt 6.0 Whey powder 8.1 Guar gum 0.3 Black pepper 0.3 Pine nuts 11.0 Fresh garlic 8.5 Parmesan cheese 8.5 Sunflower seed oil 28.0 100.0

Claims (15)

2806 52 -10 - The mix was cut under vacuum until a fine emulsion was obtained. The water activity of the mix was 0.8S. The product was packed into lOOg pouches made from low oxygen transmission material and sealed to avoid air. The pouches were stored at -20°C. For use, the entire content of the pouch which was still fluid at -20°C, was mixed with 250 gram of dry pasta which had been cooked in unsalted water. 5. MINT Freshly picked mint leaves were washed, spin-dried and mixed with the following 10 ingredients: % by weight Mint leaves 50 Dextrose 11 Whey powder 15 15 Glycerol 10 Guar gum 0.2 Sodium erythorbate 0.8 Sunflower seed oil 13 20 The mixture was chopped under a nitrogen stream as in example 2 for 60 seconds. The product has a water activity of 0.84. It was packed into low oxygen transmission plastic bags which were sealed so as to minimise any headspace air and stored at -20°C. After 12 months storage, there was no appreciable deterioration in colour or flavour. 25 ^5 \ A .«pg,?4 Q 280 6 5 2 VVKAT/JWE claim IS -11- -CLAIMS; 4 ' " 4

1. A non acid herb product comprising the leaves, flowers, barks, fruits or other aromatic parts of plants normally used for culinary purposes which have been intimately mixed: 5 (a) in the absence of oxygen with either a salt or mixture of salts or an oxygen scavenging agent or a mixture thereof together with such concentrations of water activity controlling solutes that the water activity of the mix is 0.90 or lower, or (b) in the presence of oxygen with an oxygen scavenging agent with or 10 without a salt or mixture of salts together with such concentrations or water activity controlling solutes that the water activity of the mix is 0.90 or lower the resultant product being stored in an oxygen free or substantially oxygen free atmosphere and remaining unfrozen at temperatures within the range of +8°C to - 20°C. 15

2. A herb product as claimed in claim 1 wherein said edible salt is selected from the group consisting of sodium chloride, potassium chloride, calcium chloride, sodium citrate or sodium lactate.

3. A herb product as claimed in claim 1 wherein the oxygen scavenger is selected from the group consisting of ascorbic acid or its salts, erythorbic acid or its salts. 20

4. A herb product as claimed in claim 1 wherein the water activity controlling agent is selected from the group consisting of salts such as sodium chloride, sugars, polyhydric alcohols, protein hydrolysates and hydrolysed starches.

5. A herb product as claimed in claim 4 where said sugars comprise lactose, dextrose and maltose. 25

6. A herb product as claimed in claim 1 wherein a pH controlling substance is added to the mix.

7. A herb product as claimed in claim 6 wherein the pH controlling substance comprises sodium citrate, sodium lactate or citric acid emulsifiers.

8. A herb product as claimed in claim 1 wherein the product also cont 30 oils, flavourings, essential oils and oleoresins, stabilisers, emulsifiers components.

9. A herb product as claimed in claim 1 wherein the water activi ^S1311p!WydawWib>piiiS8Q31'1top»nl I- 28 0 65 2 - 12- below 0.85.

10. A herb product as claimed in claim 1(a) wherein the mixing is carried out in an inert gas such as nitrogen or under vacuum.

11. A herb product as claimed in claim 1 wherein said product is stored at 5 temperatures ranging between 8°C and -20°C and remains in a flowable state.

12. A herb product as claimed in claim 1 wherein said product is pasteurised in the absence of oxygen.

13. A herb product as claimed in claim 1 wherein the herbs are selected from the group comprising basil, coriander (cilantro), oregano, tarragon, mint, parsley, chives, 10 chervil and other aromatic plants such as red peppers, chillies, garlic and ginger.

14. A food product whenever prepared containing a herb product as claimed in any one of claims 1 - 13.

15. A herb product as claimed in claim 1 substantially as hereinbefore described with reference to the accompanying Examples. DATED THIS 3S 19 A. J. PARK & SON PER: "S-.fkya~iL. AGENTS FOR THE APPII OA NTS END OF CLAIMS