WO2020128082A1

WO2020128082A1 - Yoghurt suitable for cooking

Info

Publication number: WO2020128082A1
Application number: PCT/EP2019/086871
Authority: WO
Inventors: Emmanuelle FLORENTIN; Aurore Celine CHETIOUI; Aurélie ENAULT
Original assignee: Société des Produits Nestlé S.A.
Priority date: 2018-12-21
Filing date: 2019-12-20
Publication date: 2020-06-25
Also published as: EP3897172A1; CN113271783A; BR112021012099A2; CL2021001649A1

Abstract

A yoghurt which remains heat-stable at a cooking temperature of 120°C for a time of at least 5 minutes is disclosed. The yoghurt has a pH ranging from 4.0 to 5.5 and comprises Streptococcus thermophilus and Lactobacillus delbruekii subsp. bulgaricus. The yoghurt further comprises from 0.1wt% to 1.5wt% of low methoxyl pectin, from 1.5wt% to 2.8wt% of native starch and from 3wt% to 8wt% of fat. Moreover, the yoghurt does not contain other stabilizing agent than native starch or low methoxyl pectin. A food product comprising such a heat-stable yoghurt, the use of such a heat-stable yoghurt and a method for preparing a food product with such a heat-stable yoghurt are also disclosed.

Description

YOGHURT SUITABLE FOR COOKING

TECHNICAL FIELD

The present invention relates generally to the field of yoghurts. Especially, the present invention relates to yoghurts suitable for cooking, in particular preparing savoury dishes.

BACKGROUND OF THE INVENTION

Culinary creams, available under ambient or chilled storage conditions, are commonly used for the preparation of either sweet dishes (e.g. whipped cream, desserts) or savoury dishes (e.g. culinary sauce or marinade). The preparation of a sweet or savoury dish may require cooking of the cream at medium or high temperatures. For example, the cream may be cooked at high temperature with aromatic ingredients (e.g. herbs) for the preparation of a hot culinary sauce suitable for serving with meat or fish.

Nowadays, there is a growing interest in the use of yoghurt, instead of culinary creams, for the preparation of sweet or savoury dishes. The advantages of using yoghurt, instead of traditional culinary creams, are the lower fat content and fresh notes and/or light textures it provides to dishes.

This trend of using yoghurt for culinary applications has been strengthened by the popularity of Greek yoghurt with the consumers. Indeed, Greek yogurt is a common ingredient in Greek cooking. Famous savoury Greek dishes include the trendy Greek yoghurt in their ingredient list. As an example, tzatziki, is a dipping sauce containing raw, chilled Greek yoghurt mixed with cucumbers, garlic, salt, olive oil and herbs.

Most of the time yoghurt is simply used as it is, without heating, for the preparation of dishes. Nevertheless, in some cases, the preparation of the dishes requires heating the yoghurt at medium or high temperatures. However, yoghurts on the market are not suitable for cooking at such medium or high temperatures. Indeed, when cooked at such temperatures, the yoghurt is unstable and undergoes a phase separation, such as protein flocculation and whey separation. These phenomena adversely affect the organoleptic properties of the yoghurt and so the organoleptic properties of the dish in which it is used. This is why it is recommended to let the yoghurt reach room temperature before using it for cooking and to never let it boil. However, these recommendations are too constraining for the consumers. Moreover, with the advent of clean-label products, consumers are looking for natural food products with the shortest list of ingredients. Most of the culinary creams and culinary yoghurts on the market contain non-natural additives, such as non-natural stabilizing ingredients, such as carrageenan or modified starch, which are not well perceived by the consumers.

EP 0 049 927 A1 (DMV-Campina B.V) relates to a yoghurt-based mayonnaise-type dressing having good keeping characteristics. The products disclosed in the Examples have a high fat content (i.e above 9wt%) and/or comprise other stabilizing agent than native starch or low methoxyl pectin. XP055557379 (Mintel datasheet with Record ID 4308439) discloses a no sugar-added yoghurt drink comprising Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, citrus pectin and corn starch and having a fat content of 6.1wt%. XP055557379 does not explicitly disclose a low methoxyl pectin and a native starch.

XP055557381 (Mintel datasheet with Record ID 4876365) discloses a yoghurt comprising Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, pectin, hydroxypropyl starch phosphate and having a fat content of 3.1wt%. XP055557381 does not explicitly disclose a low methoxyl pectin. Moreover, it discloses a product comprising other stabilizing agent than native starch and low methoxyl pectin such as modified starch, agar agar and gelatin.

US 4 430 349 A (The Coca-Cola Company) discloses an artificially-sweetened yoghurt having a pH between 4 and 5 and a fat content comprised between 0.5wt% and 3.5wt% which is prepared by mixing a stabilizer solution with a yoghurt. The stabilizer solution contains high methoxyl pectin, low methoxyl pectin, an artificial sweetener and a calcium ion sequestering agent (e.g EDTA). The yoghurt of US 4430 349 A does not comprise any starch, including native starch and comprise other stabilizing agent than native starch and low methoxyl pectin such as high methoxyl pectin.

XP055557384 (Oh et al.) is a scientific publication assessing the effect of potato starch addition on the acid gelation of milk. The yoghurts that are assessed do not comprise low methoxyl pectin. Moreover, there is no assessment of the heat-stability of the yoghurts in this scientific publication.

XP055557387 is a scientific publication assessing the impact of native and chemically modified starches addition as fat replacers in the viscoelasticity of reduced-fat stirred yoghurt. The yoghurts that are assessed do not comprise low methoxyl pectin. Moreover, there is no assessment of the heat-stability of the yoghurts in this scientific publication. None of the preceding prior art documents disclose a yoghurt exhibiting a heat- stability upon heating. Moreover, none of the preceding prior art documents disclose a yoghurt comprising at the same time a low-fat content (i.e. 3-9wt% fat) and comprising only two stabilising agents: native starch and low methoxyl pectin.

XP055557389 (Ricardo cuisine.com, "cuisiner avec le yogourt") discloses different way of using yoghurt for culinary applications. It mentions the issue of protein flocculation within the yoghurt during cooking. To overcome this undesirable phenomenon, this document provides three alternative recommendations. First, it recommends adding maize flour into the dish being cooked before adding yoghurt. Second, it recommends adding cooked maize flour into the yoghurt before adding the yoghurt into the dish being cooked. Finally, it recommends adding directly the yoghurt in the dish being cooked by taking care to heat it slowly. For that three recommendations, this prior art document underlines that the yoghurt shall never be boiled or undergo a long-lasting cooking.

XP055557389 does not disclose a yoghurt comprising only two stabilising agents at low concentration: native starch and low methoxyl pectin. Moreover, XP055557389 discloses that a yoghurt is not stable upon boiling and long-lasting cooking.

XP055557391 (Marmiton, "Gateau au yaourt") discloses the recipe of a cake made with yoghurt. No more information is provided about the composition of the yoghurt. Moreover, the yoghurt is mixed with a high quantity of flour and oil. Especially, the cake comprises 3 pots of flour and ½ pot of rapeseed oil against 1 pot of yogurt.

XP055557391 does not disclose a ready-to-use yoghurt having a low-fat (i.e. 3-9wt% fat) and comprising only two stabilising agents at low concentration: native starch and low methoxyl pectin.

Therefore, there is a need of a clean-label ready-to-use yoghurt suitable for cooking that remains stable at medium or even high temperatures.

Any reference to prior art documents in this specification is not to be considered an admission that such prior art is widely known or forms part of the common general knowledge in the field.

SUMMARY OF THE INVENTION

The object of the present invention is to improve the state of the art, and in particular to provide a composition that overcomes the problems of the prior art and addresses the needs described above, or at least to provide a useful alternative. The inventors were surprised to see that the object of the present invention could be achieved by the subject matter of the independent claims. The dependent claims further develop the idea of the present invention.

Accordingly, an embodiment of the invention proposes a yoghurt, which has a pH ranging from 4.0 to 5.5, which comprises Streptococcus thermophilus and Lactobacillus delbruekii subsp. bulgaricus, and which comprises from 0.1wt% to 1.5wt% of low methoxyl pectin, from 1.2wt% to 2.8wt% of native starch, from 3wt% to 9wt% of fat, and wherein the yoghurt remains heat-stable at a cooking temperature of 120°C for a time of at least 5 minutes and wherein the yoghurt does not contain other stabilizing agent than native starch or low methoxyl pectin. Advantageously, the yoghurt is suitable for culinary applications.

Preferably, the native starch is selected from the group consisting of native maize starch, native waxy maize starch, native pea starch, native potato starch, native rice starch, native tapioca starch, native wheat starch and combinations thereof.

The yoghurt may comprise from 2.5wt% to 4wt% of proteins, preferably the proteins consist essentially of milk proteins. The yoghurt comprises fat, such as milk fat, preferably consisting essentially of milk fat. The yoghurt has a Domic acidity ranging from 65°D to 85°D, wherein one degree Domic corresponds to O.lg of lactic acid per litre of final product.

The yoghurt may have a Brookfield viscosity ranging from 150000 to 250000 mPa.s, when measured after 10 days of storage with a Brookfield rheometer, using a cross-shaped probe reference T bar 93, at a rotation speed of 5 rpm at 8°C. The yoghurt may remain shelf- stable over a period ranging from 28 days to 3 months at 8°C.

Preferably, the cooking temperature is above the boiling temperature of the yoghurt.

An embodiment of the invention further proposes a food product comprising the yoghurt described therein. For instance, the food product may be selected from batters, biscuits, cakes, desserts, doughs, marinades, marinated fishes, marinated meats, pies, prepared dishes, purees, quiches, salad dressings, sauces, souffles, soups, and whipped creams.

Hence, another embodiment of the invention proposes the use of a yoghurt described therein for cooking at a temperature ranging from 50°C to 210°C.

Another embodiment of the invention also proposes a method for preparing a food product comprising the steps of:

(a) heating a yoghurt as described therein, from a storing temperature directly to a cooking temperature, to obtain a heated yoghurt, wherein the storing temperature ranges from 3°C to 10°C, and wherein the cooking temperature is above the boiling temperature of the yoghurt;

(b) combining the yoghurt with a food product

wherein step (b) is performed before, during step and/or after step (a).

These and other aspects, features and advantages of the invention will become more apparent to those skilled in the art from the detailed description of embodiments of the invention, in connection with the attached drawings.

DETAILED DESCRIPTION OF THE INVENTION

As used in the specification, the words "comprise", "comprising" and the like are to be construed in an inclusive sense, that is to say, in the sense of "including, but not limited to", as opposed to an exclusive or exhaustive sense. As used in the specification, the words "consisting of" and the like are to be construed in an exclusive or exhaustive sense: they exclude any unrecited element, step, or ingredient. As used in the specification, the words "consists essentially of" mean that specific further components can be present, namely those not materially affecting the essential characteristics of the invention.

As used in the specification, the singular forms "a", "an", and "the" include plura l referents unless the context clearly dictates otherwise.

As used in the specification, the term "substantially free" means that no more than 10 weight percent, preferably no more than 5 weight percent, and more preferably no more than 1 weight percent of the excluded material is present. In a preferred embodiment, "substantially free" means that no more than 0.1 weight percent of the excluded material remains. "Entirely free" typically means that at most only trace amount of the excluded material is present, and preferably, no detectable amount is present. Conversely, "substantially all" typically means that at least 90 weight percent, preferably at least 95 weight percent, and more preferably at least 99 weight percent of the material is present.

Unless noted otherwise, all percentages in the specification refer to weight percent, where applicable.

As used herein, the term "suitable for culinary applications" refers to a food product suitable at least for cooking at a temperature ranging from 50°C to 210°C, preferably ranging from 100°C to 210°C, more preferably from 120°C to 210°C. It may also refer to a food product suitable for: mixing with beverage containing at least 5wt% of ethanol (e.g. wine), and/or dissolution in a hydrophilic liquid, especially water, sauces, broths or soups. Especially, the food product does not undergo any texture destabilisation phenomenon, such as protein flocculation or whey separation, when prepared in the foregoing conditions.

As used herein, the term "hydrophilic liquid" refers to a liquid, which has a water content ranging from 50wt% to 100wt%.

As used herein, the term "yoghurt" refers to a dairy product obtained by lactic acid fermentation by means of the action of at least two types of thermophilic microorganisms: Streptococcus thermophilus and Lactobacillus delbruekii subsp. bulgaricus, starting with milk and dairy ingredients.

Unless defined otherwise, all technical and scientific terms have and should be given the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

In a first aspect, the invention relates to a yoghurt. Preferably, the yoghurt is a plain yoghurt. The yoghurt may be a drinkable yoghurt or a spoonable yoghurt. Examples of spoonable yoghurts include set yoghurts, stirred yoghurts and strained yoghurts. Preferably, the yoghurt is a spoonable yoghurt. For culinary applications, the spoonable yoghurts are preferred because the spoonable yoghurts have a thicker texture than the drinkable yoghurts and their texture is comparable to the texture of standard culinary creams. Hence, contrary to the drinkable yoghurts, the spoonable yoghurts have a sufficient consistency to provide body to dishes such as culinary sauces or soups. Most preferably, the yoghurt is a stirred yoghurt. The stirred yoghurts are advantageous for culinary applications because they are easily pourable and/or spreadable. Hence, the stirred yoghurts are easy to handle during the preparation of a dish. In a particular embodiment, the yoghurt is suitable for culinary applications.

The yoghurt has an acidic pH. Especially, the yoghurt has a pH ranging from 4.0 to 5.5, preferably ranging from 4.0 and 4.6. In a further embodiment, the yoghurt has a Domic acidity ranging from 65°D to 85°D, preferably from 70°D to 80°D. The Domic acidity of a yoghurt is expressed in degree Domic (°D). One degree Domic corresponds to O.lg of lactic acid per litre of final product, for example milk. The Domic acidity may be measured according to the method disclosed in Example 1.

Contrary to neutral dairy products, a yoghurt, due to its acidic pH, is advantageous in terms of hygiene and microbiological spoilage concerns. Indeed, an acidic pH is less favourable than a neutral pH for the development of pathogenic microorganisms. In addition, due to their acidity characterized by the pH and Domic acidity, yoghurts provide fresh notes to dishes contrary to classical culinary creams. Moreover, the acidity of a yoghurt may enhance the perception of certain aromas (e.g. fruits aromas).

The yoghurt comprises from 3wt% to 9wt% of fat, especially from 4wt% to 8wt% of fat. More preferably, the yoghurt comprises 8% of fat. The classical culinary creams have a fat content ranging from 15wt% to 30wt% of fat. Hence, the yoghurt of the invention is a nutritional alternative to classical culinary creams in terms of fat content. Indeed, the yoghurt has two times less, even three times less fat than classical culinary creams. In a preferred embodiment, the fat consists essentially of milk fat. The fat is known to stabilize the proteins upon cooking. In the present invention, a heat-stable yoghurt may be achieved, even in the presence of a low fat content ranging from 3wt% to 9wt%.

In a further embodiment, the yoghurt comprises from 2.5wt% to 4wt% of proteins, especially from 2.8wt% to 3.5wt% of proteins. Most preferably, the yoghurt comprises 3wt% of protein. Without wishing to be bound by theory, the inventors believe that where the protein content is below 2.5, the viscosity of the yoghurt would be too low for cooking application. Preferably, the proteins consist essentially of milk proteins.

The yoghurt comprises Streptococcus thermophilus and Lactobacillus delbruekii subsp. bulgaricus. These two lactic acid bacteria strains are present in a viable form in the yoghurt. Streptococcus thermophilus and Lactobacillus delbruekii bulgaricus are typical yoghurt bacteria strains. Under French regulation, a fermented milk must comprise specific levels of these two species in order for it to be designated by the word "yoghurt". More details are available in the norm AFNOR NF 04-600 and the norm Codex Stan A-lla-1975. In another embodiment, the yoghurt according to the invention, or a fermented milk, may comprise lactic acid bacteria other than Streptococcus thermophilus and Lactobacillus delbruekii subsp. Bulgaricus. The additional species or strains are intended to impart various properties to the yoghurt, or fermented milk. Such properties include the promotion of the equilibrium of gut microbiota. Examples of lactic acid probiotic strains include microorganisms derived from Bifidobacterium, Bacillus coagulans, Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus johnsonii, Lactobacillus paracasei, Lactobacillus rhamnosus strains and mixtures thereof.

The yoghurt comprises from 0.1wt% to 1.5wt% of low methoxyl pectin. Preferably, the yoghurt comprises from 0.1wt% to 1.0wt% of low methoxyl pectin, more preferably from 0.2wt% to 0.5wt% of low methoxyl pectin. Most preferably, the yoghurt comprises 0.2wt% of low methoxyl pectin. The term "low methoxyl pectin" refers to a pectin having a degree of esterification (DE) of less than 50%, preferably ranging from 20% to 50%. More preferably, the low methoxyl pectin has a degree of esterification of 23%. The degree of esterification (DE) is defined as the number of methyl-esterified galacturonic acid units expressed as a percentage of the total galacturonic acid units in the pectin molecule. Low methoxyl pectins are preferred over high methoxyl pectins because the dairy product may exhibit whey syneresis before the fermentation step, when high methoxyl pectin is used. Whey syneresis impacts adversely the fermentation step. Preferably, the low methoxyl pectin is a naturally-occurring low methoxyl pectin because naturally-occurring low methoxyl pectins are better perceived by consumers than artificial low methoxyl pectins. Examples of low methoxyl pectin source include apple or citrus fruit. Hence, in a preferred embodiment, the yoghurt is substantially free of high methoxyl pectin. More preferably, the yoghurt is entirely free of high methoxyl pectin. In another embodiment, the low methoxyl pectin may be a partially amidated low methoxyl pectin. By "partially amidated low methoxyl pectin", it is understood a pectin having a degree of amidation (DA) which is less than 50%, preferably ranging from 20% to 50%. More preferably, the degree of amidation of the partially amidated low methoxyl pectin is of 24%. The degree of amidation (DA) is the content of amide groups expressed as a percentage of the number that is the sum of the number of methyl-esterified carboxyl groups plus the number of unesterified carboxyl groups plus the number of amide groups. Without wishing to be bound by theory, the inventors believe that the use of a partially amidated low methoxyl pectin may improve the heat-stability of the yoghurt of the invention.

The yoghurt comprises from 1.2wt% to 2.8wt% of native starch. Preferably, the yoghurt comprises from 1.2 wt% to 2.5 wt% of native starch, more preferably from 1.3wt% to 2.3wt% of native starch. Most preferably, the yoghurt comprises 1.33wt% of native starch. "Native starch" refers to a naturally-occurring starch which has not been treated physically, enzymatically, nor chemically to change its properties. On the contrary, "modified starch" refers to a native starch which has been treated physically, enzymatically, or chemically to change its properties. Native starches are preferred because they are perceived by consumers better than modified starches. Especially, the native starch is selected from the group consisting of native maize starch, native waxy maize starch, native pea starch, native potato starch, native rice starch, native tapioca starch, native wheat starch and combinations thereof. Preferably, the native starch is native tapioca starch. In a further embodiment, the yoghurt is substantially free of modified starches. Preferably, the yoghurt is entirely free of modified starches. Especially, the inventors have discovered that a heat-stable yoghurt may be achieved without the use of modified starches.

The native starch and the low methoxyl pectin are used to stabilize the yoghurt during its shelf life and also during cooking at temperatures greater than 50°C. They are also used to ensure that the yoghurt withstands the potentially rapid temperature increase during cooking from storing temperature to cooking temperature. Especially, the yoghurt remains heat-stable at a cooking temperature of 120°C during a time of at least 5 minutes. In a preferred embodiment, the yoghurt remains heat-stable at a cooking temperature of 120°C during a time of at least 6 minutes, at least 7 minutes, at least 8 minutes, at least 9 minutes, at least 10 minutes, at least 15 minutes, at least 20 minutes, at least 25 minutes, at least 30 minutes, at least 35 minutes, at least 40 minutes, at least 45 minutes, at least 50 minutes, at least 55 minutes, at least 60 minutes, at least 70 minutes, at least 80 minutes, at least 90 minutes, at least 100 minutes, at least 110 minutes or at least 120 minutes. Preferably, the yoghurt remains heat-stable at a cooking temperature of 120°C during a time ranging from 5 minutes to 120 minutes, from 5 minutes to 60 minutes or from 5 minutes to 30 minutes. More preferably, the yoghurt remains heat-stable at a cooking temperature of 120°C during a time ranging from 10 minutes to 120 minutes, from 10 minutes to 60 minutes or from 10 minutes to 30 minutes. Most preferably, the yoghurt remains heat-stable at a cooking temperature of 120°C during a time ranging from 15 minutes to 120 minutes, from 15 minutes to 60 minutes or from 15 minutes to 30 minutes. "Heat-stable" means that the yoghurt does not exhibit phase separation, such as protein flocculation or whey separation, at a targeted cooking temperature (e.g. 120°C). In a preferred embodiment, the yoghurt remains heat-stable at a cooking temperature of 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C or 210°C during a time of at least 5 minutes. Preferably, the yoghurt remains heat-stable at a cooking temperature of 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C or 210°C during a time of at least 6 minutes, at least 7 minutes, at least 8 minutes, at least 9 minutes or at least 10 minutes. More preferably, the yoghurt remains heat-stable at a cooking temperature of 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C or 210°C during a time of at least 15 minutes, at least 20 minutes, at least 25 minutes, at least 30 minutes, at least 35 minutes, at least 40 minutes, at least 45 minutes, at least 50 minutes, at least 55 minutes, at least 60 minutes, at least 70 minutes, at least 80 minutes, at least 90 minutes, at least 100 minutes, at least 110 minutes or at least 120 minutes. In a most preferred embodiment, the cooking temperature is above the boiling temperature of the yoghurt. The boiling temperature corresponds to the temperature at which the yoghurt starts to boil or simmer, when cooking. Boiling or simmering of the yoghurt is visible during cooking by the appearance of bubbles within the yoghurt. The inventors have discovered that the yoghurt has outstanding heat-stability, even when the cooking temperature is above the boiling temperature of the yoghurt.

In another embodiment, the yoghurt remains shelf-stable over a period ranging from 28 days to 90 days at 8°C. "Shelf-stable" means that the yoghurt does not spoil over shelf life and does not exhibit any whey separation at a targeted storage temperature (e.g. 8°C). "Spoilage" refers to the development of unwanted micro-organisms in the yoghurt, such as bacteria or moulds that may affect the organoleptic properties of the yoghurt negatively, or that may be pathogenic.

Without wishing to be bound by theory, the inventors believe that the combination of low methoxyl pectin and native starch enables to significantly stabilize a yoghurt over its shelf life and over cooking at temperatures over 50°C, even in the presence of a low fat content. Low methoxyl pectin and native starch are known to have a low stability upon heating at temperatures over 50°C. Usually, high methoxyl pectin and modified starch are commonly used to stabilise cream. Indeed, high methoxyl pectin and modified starch have better stability properties, such as heat-stability properties and shelf-stability properties, than low methoxyl pectin and modified starch, due to their chemical structure. Particularly, modified starches undergo physical, enzymatic, or chemical treatment such that their heat-stability is improved. In addition, the fat content is known to participate in improving the heat-stability of a food product. This is why, due to their high fat content, culinary creams are heat-stable. Low-fat culinary creams, that-is-to-say culinary creams having a fat content lower than 15wt% are known in the art. However, such low-fat culinary creams contain non-naturally occurring stabilizing agents (e.g. modified starch) and emulsifying agents to offset the low heat-stability resulting from their low fat content. The inventors have shown that the combination of low methoxyl pectin and native starch is sufficient to obtain a heat-stable yoghurt despite a low fat content.

Therefore, the yoghurt of the invention has the advantage to be significantly shelf- stable and heat-stable while having a low fat content and containing only two stabilizing agents which are well-perceived by the consumers, namely native starch and low methoxyl pectin. In a preferred embodiment, the yoghurt does not contain other stabilizing agent than native starch or low methoxyl pectin. In other terms, the yoghurt is entirely free of other stabilizing agent than native starch or low methoxyl pectin . Examples of other stabilizing agent than native starch or low methoxyl pectin include acacia gum, alginate, carboxymethylcellulose, carrageenan, cellulose, gelatine, gellan, guar gum, inulin, locust bean gum, xanthan gum and mixtures thereof Especially, the yoghurt does not contain a stabilizing agents selected from the group consisting of acacia gum, alginate, carboxymethylcellulose, carrageenan, cellulose, gelatine, gellan, guar gum, inulin, locust bean gum, xanthan gum and mixtures thereof. Based on the foregoing, the yoghurt comprises a stabilizing system which only consists of native starch and low methoxyl pectin. By stabilizing system, it is understood all the added ingredients that participate in stabilizing the yoghurt upon heating (i.e heat- stability) and upon shelf-life (i.e shelf-stability).

Indeed, to meet consumers' expectations, it is desirable to obtain a shelf-stable and heat-stable yoghurt with naturally-occurring ingredients and with a minimum of additives, especially with only two stabilizing agents. The inventors have discovered that native starch and pectin were sufficient to stabilize the yoghurt over shelf life and upon heating at a temperature over 50°C. The inventors have discovered that a heat-stable yoghurt may be achieved without the addition of any other stabilizing agent than native starch or low methoxyl pectin. Especially, the inventors have discovered that a heat-stable low-fat yoghurt may be achieved with only two ingredients which are well perceived by consumers: native starch and low methoxyl pectin.

In another embodiment, the yoghurt is entirely free of any emulsifying agent. Especially, the yoghurt is entirely free of emulsifying agent selected from the group consisting of acetic esters of mono- and diglycerides of fatty acids, citric esters of mono- and diglycerides of fatty acids, lactic acid esters of mono- and diglycerides of fatty acids, lecithin, mono- and diglycerides of fatty acids, polyglycerol fatty acid esters, polyglycerol polyricinoleate (PGPR), polysorbates (polyoxyethylene sorbitan esters), tartaric esters of mono- and diglycerides of fatty acids and mixtures thereof. Standard culinary comprise several emulsifying agents. The yoghurt of the invention is heat-stable and shelf-stable, even in the absence of any emulsifying agents. For avoidance of doubts, low methoxyl pectin and native starch are not considered as emulsifying agents in the sense of the invention.

The yoghurt has a Brookfield viscosity ranging from 150000 to 250000 mPa.s when measured after 10 days of storage with a Brookfield rheometer/viscometer, using a cross- shaped probe reference T bar 93 (spindle No 93), at a rotation speed of 5 rpm, at 8°C. Without wishing to be bound by theory, this viscosity range seems to correspond to a texture suitable for culinary applications. The texture is such that the yoghurt is easily pourable, easily spreadable and adapted for the preparation of dishes such as culinary sauces or soups.

The yoghurt may further comprise vitamins and minerals to improve its nutritional profile.

In a second aspect, the invention relates to a food product comprising a yoghurt as described above. The food product is selected from the list consisting of batters, biscuits, cakes, desserts, doughs, marinated fishes, marinated meats, marinades, pies, prepared dishes, purees, quiches, salad dressings, sauces, souffles, soups, and whipped creams.

In a third aspect, the invention relates to the use of a yoghurt as described in the first aspect of the invention for cooking at a temperature ranging from 50°C to 210°C. Preferably, the temperature ranges from 80°C to 150°C. More preferably, the temperature ranges from 100°C to 150°C. At these temperature ranges, the yoghurt remains heat-stable during a time of at least 5 minutes. Preferably, at these temperature ranges, the yoghurt remains heat- stable during a time of at least 6 minutes, at least 7 minutes, at least 8 minutes, at least 9 minutes, at least 10 minutes, at least 15 minutes, at least 20 minutes, at least 25 minutes, at least 30 minutes, at least 35 minutes, at least 40 minutes, at least 45 minutes, at least 50 minutes, at least 55 minutes, at least 60 minutes, at least 70 minutes, at least 80 minutes, at least 90 minutes, at least 100 minutes, at least 110 minutes or at least 120 minutes. More preferably, at these temperature ranges, the yoghurt remains heat-stable during a time ranging from 10 minutes to 120 minutes, from 10 minutes to 60 minutes or from 10 minutes to 30 minutes. Most preferably, at these temperature ranges, the yoghurt remains heat-stable at a cooking temperature of 120°C during a time ranging from 15 minutes to 120 minutes, from 15 minutes to 60 minutes or from 15 minutes to 30 minutes.

In a fourth aspect, the invention relates to a method for preparing a food product. I n a first step (a), a yoghurt according to the invention is heated from a storing temperature directly to a cooking temperature to obtain a heated yoghurt. The phrase "from a storing temperature directly to a cooking temperature" means that the yoghurt is not left to reach room temperature before it is brought to cooking temperature. For instance, the yoghurt is heated to a cooking temperature within 180 seconds, 120 seconds, 60 seconds or preferably 30 seconds after it is taken from storage at a storing temperature. The storing temperature ranges from 3°C to 10°C. For instance, it is the temperature of a refrigerator. The cooking temperature is above the boiling temperature of the yoghurt. The boiling temperature corresponds to the temperature at which the yoghurt starts to boil or simmer, when cooking. Boiling or simmering of the yoghurt is visible during cooking by the appearance of bubbles within the yoghurt. Preferably, the cooking temperature is lower than 210°C. More preferably, the cooking temperature is lower than 190°C, 180°C, 170°C, 160°C, 150°C, 140°C, 130°C or 120°C. The yoghurt may be heated with a firewood, an electric hob, an induction hob, a gas hob an oven, and a water bath. For example, yoghurt may be heated in a frying pan, saucepan, pressure cooker and/or a gratin dish.

In other words, the yoghurt may be taken out of a refrigerator, or other chilled storage device at a temperature between 3°C and 10°C, and poured directly into a cooking device already at a cooking temperature, such as between 120°C and 210°C. As explained above, "poured directly" means that the yoghurt does not need to be left to rest at ambient temperature, before it is poured into the cooking device. The yoghurt may be poured into the cooking device within less than 180 seconds after withdrawal from the storage device.

In a second step (b), the yoghurt is combined with a food product. Step (b) may be performed before, during step and/or after step (a).

Usually, it is recommended to let the yoghurt reach room temperature before using it for cooking and to never let it boil. Without wishing to be bound by theory, the inventors believe that these recommendations aim at avoiding that the yoghurt undergoes phase separation, such as protein flocculation and whey separation, upon heating.

The yoghurt according to the present invention remains heat-stable even when it is brought to cooking temperature without having been brought to room temperature before cooking. Moreover, the yoghurt according to the present invention remains heat-stable even after boiling. The yoghurt according to the present invention does not exhibit phase separation, such as protein flocculation or whey separation, when it is cooked directly from storing temperature and/or after boiling.

In another aspect, the invention also relates to a method for preparing a food product comprising the step of mixing the yoghurt according to the first aspect of the invention with a beverage containing at least 5wt% of ethanol. Examples of beverage containing at least 5wt% of ethanol include armagnac, beer, calvados, champagne, cognac, liquor, pastis, port wine, rhum, vodka, wine, whisky and mixtures thereof. Especially, the yoghurt does not undergo any texture destabilisation phenomenon, such as protein flocculation or whey separation, when mixed with a beverage containing at least 5wt% of ethanol. In a further aspect, the invention relates to a method for preparing a food product comprising the step of diluting the yoghurt according to the first aspect of the invention in a hydrophilic liquid. Examples of hydrophilic liquid include water, sauces, broths or soups. The yoghurt has good diluting properties in hydrophilic liquids and provides body to the hydrophilic liquid due to its consistency. Moreover, the yoghurt does not undergo any texture destabilisation phenomenon, such as protein flocculation or whey separation, when diluted in a hydrophilic liquid.

Those skilled in the art will understand that they can freely combine all features of the present invention disclosed herein. In particular, features described for the product of the present invention may be combined with the use of the present invention and vice versa. Further, features described for different embodiments of the present invention may be combined.

Furthermore, where known equivalents exist to specific features, such equivalents are incorporated as if specifically referred in this specification. Further advantages and features of the present invention are apparent from the figures and non-limiting examples.

EXAMPLES

Example 1: Analytical Method of Dornic acidity

The degree Dornic is measured with an automatic acidometer Metrohm (Titrino n°719, Sample changer n°730) coupled with an electrode Metrohm ref 6.0233.100. The measures of the acidometer are analysed with the software TIAMO version 2.5.

The acidometer is calibrated respectively with a first buffer solution having a pH of 4.01, a second buffer solution having a pH of 9.21 and a third buffer solution having a pH of 7.00.

Before measuring the degree Dornic, the yoghurt samples are prepared. Samples of lOg of homogenised yogurt are prepared. The samples are diluted by adding 50mL of water. The samples are then stirred during 5 minutes.

The automatic acidometer measures the initial pH of the sample and then adds sodium hydroxide N/9 (i.e. at a concentration of 0.111 mol/L) until a pH of 8.3 is reached. The amount of sodium hydroxide N/9 added to reach a pH of 8.3 is measured by the automatic acidometer. Thereafter, the software TIAMO version 2.5 provides the degree Dornic. Example 2: Preparation of a yoghurt according to the present invention

A yoghurt according to the present invention was prepared. First, dairy ingredients (milk and cream) were mixed with low methoxyl pectin and native starch according to the recipe of table 1 to obtain a dairy mixture.

Table 1

Then, the dairy mixture was preheated at 60°C and underwent a two-step homogenisation (upstream homogenisation). Especially, the dairy mixture underwent a first homogenisation step at 150 bar followed by a second step homogenisation at 50 bar. The dairy mixture was thereafter pasteurised at 92°C during a time of 6 minutes to obtain a pasteurised dairy mixture. The pasteurised dairy mixture was cooled down at 43°C and was incubated with starter cultures consisting of Streptococcus thermophiles and Lactobacillus delbrueckii subsp. bulgaricus (Yoflex^® Premium 3.0 from Chr. Hansen) to obtain a yoghurt. The fermentation by the starter cultures was then stopped when the target pH of 4.5 was achieved. The yoghurt was then smoothed and cooled down to 25°C, dosed into cups and stored at 8°C.

The features of the obtained yoghurt are summarized in table 2.

Table 2

Example 3: Another example of a yoghurt according to the invention

It would be possible to prepare a yoghurt according to the invention according to the process of example 2 and with the recipe of table 3.

Table 3

The features of the yoghurt are expected to be as summarized in Table 4.

Table 4 Example 4: Heat-stability assay

The heat-stability of three food products was assessed. Especially, the three food products were:

a commercial culinary cream comprising modified starch and pectin (15% of fat), a commercial Greek yoghurt which is free from any stabilizing agents (8% of fat), - a yoghurt of example 2 (7.9% of fat).

The heat-stability assay was divided into two trials. In the first trial, the above- mentioned food products were separately heated in a frying pan at a targeted temperature of 80°C. In the second trial, the food products were also separately heated in a frying pan but at a higher temperature than the one used in the first trial: a targeted temperature of 120°C.

The heat-stability of the food products was assessed by determining the appearance of protein flocculation, a result of phase separation, within the food product upon heating. The protein flocculation is a clue of heat-instability, which can be easily determined by visual inspection of the food product due to the appearance of grains. The time taken for the food product to flocculate upon heating ("flocculation time") was also measured. The starting point for flocculation time measurements (tO) was the time where the food product is introduced in a frying pan having a stable targeted temperature (here, 80°C or 120°C). "Stable targeted temperature" means that the temperature remains substantially constant during the trial. For each trial, the heat-stability was assessed for 5 minutes. A duration of 5 minutes was chosen because standard yoghurts flocculate in less than 5 minutes. Moreover, a period of 5 minutes corresponds to the usual cooking time needed to prepare food products such as sauces.

The results are summarized in table 5.

Table 5

According to the results in table 5, the commercial Greek yoghurt is not heat-stable and exhibits protein flocculation upon heating at 80°C and 120°C. The flocculation occurs quickly with a flocculation time below 5 minutes. Protein flocculation results in an unpleasant grainy texture in mouth. Moreover, grains are visible to the naked eye, which is not appealing.

On the contrary, the yoghurt according to the invention is heat stable and does not exhibit any protein flocculation upon heating at 80°C and 120°C, even after 5 minutes. This is noteworthy compared to the low flocculation time of the commercial Greek yoghurt. The yoghurt according to the invention has a heat-stability similar to that of the commercial culinary cream. An advantage of the yoghurt according to the invention is that it has a lower fat content than commercial culinary creams. The texture of the yoghurt according to the invention after heating is smooth in mouth.

Example 6: Cooked marinated chicken

The yoghurts of Example 2 and Example 3 were used to cook a marinated chicken. First, a homogeneous marinade was prepared by mixing 85wt% of yoghurt of Example

2 or Example 3 with 15wt% of spices, especially tikka masala spices. The marinade was mixed with the chicken and the chicken was allowed to marinate for at least 1 hour.

After being marinated, the marinated chicken was stewed and simmered at medium flame (above 120°C) for 10 minutes.

No evidence of heat-instability were observed, and the chicken was more tender than a chicken marinated with a standard culinary cream. Hence, the yoghurt of the invention has the ability to tenderize the meat and is heat-stable at prolonged cooking, especially upon boiling.

Example 7: Curry-based culinary sauce

The yoghurts of Example 3 and Example 2 were used to cook a curry-based culinary sauce. Especially, a homogeneous sauce mixture was prepared by mixing the ingredients of Table 6.

Table 6

The sauce mixture was simmered at medium flame (above 120°C) in a frying pan for 5 minutes. It does not exhibit clues of yoghurt destabilization. The sauce prepared with the yoghurt of the invention was stable upon simmering and upon long-lasting cooking. Especially, the sauce exhibited thickening ability upon cooking. Example 8: Beef Stroganoff

The yoghurts of Example 2 and Example 3 were used to cook a beef Stroganoff. 160 g of mushroom slices and 300g of onion slices were cooked in a sauce span at medium flame. Thereafter, 300g of beef sirloin were cut into pieces and added to the sauce span for cooking. The beef sirloin pieces were spiced with salt and pepper.

In parallel, a homogeneous sauce mixture was prepared by mixing the ingredients of table 7.

Table 7

Once the beef sirloin pieces had been sufficiently cooked, the homogenous sauce was added to the sauce span and the whole preparation was stewed for at least 5 minutes at medium flame.

The sauce appeared to be stable upon cooking at high temperature (above 120°C), even in presence of ethanol from the vodka.

Example 9: Tomato soup

Chopped onions were cooked in olive oil under tender in a sauce pan. After that, a dollop of tomato concentrate was added to the cooked onions. Thereafter, a big can of whole tomatoes and 2 glasses of water were added to the preparation made of onion, olive oil and tomato concentrate.

The obtained preparation was spiced with sal and pepper and was then transferred to a blender for mixing to obtain a homogeneous soup.

Finally, one to three spoonsful of the yoghurt of Example 2 or 3 were added to the tomato soup. The yoghurt of Example 2 and 3 showed good dissolution properties in the tomato soup and a homogenous soup was obtained after the addition of the yogurt of the invention. Moreover, the addition of the yoghurt of the invention provided body to the soup and increased the freshness of the soup. Example 10: French crepes

The yoghurts of Example 2 and Example 3 were used to prepare French crepes.

A French crepe batter was prepared by mixing the ingredients of table 8.

Table 8

A frying pan was heated. Once the frying pan was at satisfactory temperature

(between 100°C and 150°C), the frying pan was covered with a fat compound (e.g butter). Thereafter, the frying pan was covered with a thin layer of French crepe batter and was let to cook until having a satisfactory cooked French crepe.

The operation is repeated until the batter is totally consumed.

Compared to traditional French crepes, the obtained French crepes were lighter, softer and have increased freshness due to the acidity of the yoghurt.

Although the invention has been described by way of example, it should be appreciated that variations and modifications may be made without departing from the scope of the invention as defined in the claims.

Claims

1. A yoghurt, which has a pH ranging from 4.0 to 5.5, which comprises Streptococcus thermophilus and Lactobacillus delbruekii subsp. bulgaricus, and which comprises from 0.1wt% to 1.5wt% of low methoxyl pectin, from 1.2wt% to 2.8wt% of native starch, from 3wt% to 9wt% of fat, and wherein the yoghurt remains heat-stable at a cooking temperature of 120°C for a time of at least 5 minutes, and wherein the yoghurt does not contain other stabilizing agent than native starch or low methoxyl pectin.

2. The yoghurt according to claim 1, which is suitable for culinary applications.

3. The yoghurt according to any one of claims 1 to 2, wherein the native starch is selected from the group consisting of native maize starch, native waxy maize starch, native pea starch, native potato starch, native rice starch, native tapioca starch, native wheat starch and combinations thereof.

4. The yoghurt according to any one of claims 1 to 3, which comprises from 2.5wt% to 4wt% of proteins.

5. The yoghurt according to claim 4, wherein the proteins consist essentially of milk proteins.

6. The yoghurt according to any one of claim 1 to 5, which comprises fat consisting essentially of milk fat.

7. The yoghurt according to any one of claims 1 to 6, which has a Domic acidity ranging from 65°D to 85°D, wherein one degree Domic corresponds to O.lg of lactic acid per litre of final product.

8. The yoghurt according to any one of claims 1 to 7, which has a Brookfield viscosity ranging from 150000 to 250000 mPa.s when measured after 10 days of storage with a Brookfield rheometer, using a cross-shaped probe reference T bar 93, at a rotation speed of 5 rpm at 8°C.

9. The yoghurt according to any of one claims 1 to 8, which remains shelf-stable over a period ranging from 28 days to 3 months at 8°C.

10. The yoghurt according to any one of one claims 1 to 9, wherein the cooking temperature is above the boiling temperature of the yoghurt.

11. A food product comprising the yoghurt according to any one of claims 1 to 10, wherein the yoghurt has a pH ranging from 4.0 to 5.5 and comprises Streptococcus thermophilus and Lactobacillus delbruekii subsp. bulgaricus, and wherein the which comprises from 0.1wt% to 1.5wt% of low methoxyl pectin, from 1.2wt% to 2.8wt% of native starch, from 3wt% to 9wt% of fat, and wherein the yoghurt remains heat-stable at a cooking temperature of 120°C for a time of at least 5 minutes, and wherein the yoghurt does not contain other stabilizing agent than native starch or low methoxyl pectin.

12. The food product according to claim 11, which is selected from the list consisting of batters, biscuits, cakes, desserts, doughs, marinades, marinated fishes, marinated meats, pies, prepared dishes, purees, quiches, salad dressings, sauces, souffles, soups, and whipped creams.

13. Use of the yoghurt according to any one of claims 1 to 10, for cooking at a temperature ranging from 50°C to 210°C.

14. A method for preparing a food product comprising the steps of:

(a) heating the yoghurt according to any one of claims 1 to 10, from a storing temperature directly to a cooking temperature, to obtain a heated yoghurt, wherein the storing temperature ranges from 3°C to 10°C, and wherein the cooking temperature is above the boiling temperature of the yoghurt;

(b) combining said yoghurt with a food product

wherein step (b) is performed before, during step and/or after step (a).