WO2010109291A1

WO2010109291A1 - A kefir-alike composition and relating alimentary products containing it

Info

Publication number: WO2010109291A1
Application number: PCT/IB2010/000627
Authority: WO
Inventors: Alberto Giardini; Carla Orsi
Original assignee: Centro Sperimentale Del Latte S.P.A.
Priority date: 2009-03-23
Filing date: 2010-03-22
Publication date: 2010-09-30
Also published as: ITMO20090067A1

Abstract

A composition for preparing a fermented kefir-like product comprises a mixture of microorganisms made up of milk ferments.

Description

A kefir-alike composition and relating alimentary products containing it

The invention regards a composition based on microorganisms useable for preparing a food product, in particular a milk-based probiotic food product.

Known among milk-based food products is a type of fermented milk referred to as "kefir" (a word derived from Turkish "kef" or "keif" which should mean "pleasant taste" or also "wellness") and originating from North Caucasus. Kefir is an aromatic acid milk, slightly alcoholic, in that it contains ethanol at concentrations equivalent to 0.1-0.3 % v/v, and having a sparkling taste (due to the CO₂ produced during fermentation) . Kefir has a more fluid density with respect to yoghurt and it is thus considered a beverage. Kefir is rich in vitamins of group B (vitamin B₁₂, folic acid or vitamin B₉) , mineral nutrients (calcium, phosphorous) and essential amino acids (for example, tryptophan) , and thus used in medicine among the so-called "probiotic functional foods", i.e. food products supplemented with living microorganisms good for health. In particular, taking kefir allows normalising the functionality of the digestive system, preventing, and at times curing, • digestive disorders, gastritis, intestinal illnesses and diarrhoea in adults and children. The traditional method for producing kefir requires the addition of the so-called "kefir grains", containing microflora mixed with cow or goat milk. In the latter, the kefir grains thus serve as a "starter", i.e. as fermentation activators . Kefir grains are small white and yellowish coloured masses, having a diameter comprised between 1-6 mm and 1-2 cm and a twisted and wrinkled surface. Kefir grains are substantially composed of an elastic matrix of microbial origin, the kefir polysaccharide, incorporating a considerable variety of microorganisms in symbiosis, and thus stable. The microflora present in kefir grains comprises: - Milk ferments (also indicated through the acronym LAB = Lactic Acid Bacteria) , such as for example lactococci, lactobacilli, Leuconostoc spp.;

-Alcohol ferments, such as for example yeasts belonging to the Saccharomyces, Kluyveromyces genus/

-Acetic ferments, such as for example those belonging to the Acetobacter genus. Kefir grains, once recovered from the kefir, may be immediately reutilised for producing another kefir, or preserved. Kefir grains may be preserved in a refrigerator

(at a temperature comprised between +1°C and +4°C) for a few days, or they may be frozen and preserved as they are for months. Kefir grains may be "cultured" (i.e., they may be constantly provided with conditions suitable for the growth of the microflora contained therein) , continuously in such a manner to increase in number and volume, with a minimum increase equivalent to 5-10% every time another kefir is produced.

It should be observed that, in case of preservation under unsuitable hygiene conditions, kefir grains may be polluted by the so-called "wild yeasts" (natural yeasts), which generate unpleasant smell, and by coliform bacteria, putrefying microorganisms producing toxic and malodorous substances .

Hence, kefir grains need to be periodically washed using cold water, in particular every time another kefir is produced, to eliminate possible polluting surface microflora. However, this procedure has some drawbacks: as a matter of fact, even part of the useful microflora, i.e. milk ferments that are mainly present on the surface of the grain, are removed from the grain along with the polluting microflora. Given that the traditional method is quite complicated and substantially not convenient, especially when producing large amounts of kefir, instead of adding kefir grains to the milk the latter is inoculated using a so-called "starter culture". The starter culture may be made up of kefir without grains, or various (lactic, alcoholic, acetic) ferments belonging to the microbial flora of the kefir, in lyophilized form. Should lyophilized ferments be used, a beverage is achieved that is not identical to the traditional kefir (obtained by means of grains) , but that is however very similar to the latter in terms of organoleptic and nutritional properties.

In this manner, it is possible to obtain, in a substantially- easy manner, amounts of kefir sufficient to prepare probiotic food products containing kefir, for example kefir ice creams, having properties good for the health of the consumers. However, though kefir is widely common and popular in various countries and corresponding good effects on health are known, it is still difficult for the public of consumers to appreciate and accept ice cream products, in that they contain kefir, whose flavour and palatability are considerably different from those of analogous products obtained using non- fermented milk.

As a matter of fact, the known recipes for preparing ice creams based on kefir require the presence of sucrose in concentrations averagely exceeding 20% with the aim of conferring sufficient palatability to the product. However, the abundant use of sucrose is not an ideal solution for many consumers, in that it is not compatible with the dietary needs of the latter. Therefore, there arises the need for food products, for example ice creams, wherein the probiotic properties of kefir are associated to aromatic and palatability properties suitable to meet the taste of the consumers. An object of the invention is that of improving probiotic food product, by associating the probiotic properties of kefir.

Finally a further object of the present invention resides in providing a food product, based on fermented milk and/or cream, capable of combining the probiotic properties of kefir with characteristic aromatic and remarkable palatability properties .

SUMMARY OF THE INVENTION

The Applicant has surprisingly found that it is possible to reach the above targets with the kefir-like composition according to the present invention. In particular it is characterised in that it is free from acetic and alcoholic ferments and therefore it contains a mixture of microroganisms comprising at least one the following lactic ferments: a) Lactobacillus acidophilus, b) Lactobacillus casei ssp. casei, c) Lactococcus lactis ssp. lactis biovar diacetylactis, d) Leuconostoc mesenteroides ssp. cremoris

Due to the invention, a composition is provided based on microrganisms that can be used for preparing a fermented product similar to kefir as it has the same probiotic properties as this product and in any case has a pleasant aromatic taste (similar to butter taste) . The fermented "kefir-like" product thus obtained can be further used, as an ingredient, for preparing a food product. For example, cow milk may be inoculated using the composition according to the invention thereby obtaining a fermented kefir-like milk, and this kefir-like fermented milk may be further used as an ingredient for preparing a probiotic ice cream product. The latter, unlike the known kefir ice creams, has better palatability and a more pleasant taste, resulting therefore more appraisable for the public of consumers . Thanks to the pleasant taste of the fermented kefir-like product obtainable with the composition according to the invention, kefir-based ice cream products may be obtained using lesser amounts of sucrose if compared to those used in the known recipes, however meeting the dietary requirements of the consumers . Therefore a furher object of the present invention is a food product, more preferably an ice cream product comprising the milk fermented with the kefir-like compositions according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

The fermented milk and the relating ice cream product obtained with the composition according to the invention comprising as gas fermentation microrganisms only a mixture of milk ferments and this mixture being free from alcoholic and acetic ferments present in the typical microflora of kefir grains exhibits less sharp taste and therefore more pleasant than traditional kefir obtained with kefir grains. For the purposes of the present invention the following food products are comprised in the class of ice cream products: ice cream, sorbets, ice lollies, mousse, Bavarian cream. The fermented milk obtained with the composition of the present invention may also be used as filler in cold confectionary products such as Italian ice creams (semifreddi) , Zuccotti, filled brioches etc.

In the present description the components (c) and (d) of the composition according to the present invention are also identified as mesophilic lactic ferments or mesophilic component . The composition according to the present invention may contain besides the aforesaid four components may also contain at least one of the following lactic ferments selected from the group consisting of: Lactobacillus delbrueckii ssp. bulgaricus, Streptococcus thermophllus, Lactococcus lactis ssp. lactis, Lactococcus lactis ssp. cremoris (the latter two lactic ferments being of mesophilic type) . According to a particularly preferred realization of the present invention the composition comprises all the bacterial species listed in the following Table 1. Table 1

Lactobacillus acidophilus

Lactobacillus casei ssp. casei

Lactobacillus delbrueckii ssp. bulgaricus Streptococcus thermophilus

Lactococcus lactis ssp. lactis

Lactococcus lactis ssp. cremoris

Lactococcus lactis ssp. lactis biovar diacetylactis Leuconostoc mesenteroides ssp. cremoris

Among the species listed in table 1, those belonging to the Lactococcus genus and Leuconostoc genus are mesophilic species .

The main properties of the milk ferments present in the composition according to the invention are summarized hereinafter in table 2 and in table 3. Table 2 indicates the optimal range of pH values and the minimal, ideal and maximal growth temperature (° C) , while table 3 indicates the biochemical and metabolic properties (production of lactic acid, carbon dioxide and flavours; probiotic activity) :

Table 2

Microorganism ideal PH Growth temperature ⁰C)

Minimum Ideal Maximum

Lactobacillus 5.5-6 .0 27 37-45 52 5.5-6.0 15 30-38 <45 ssp.

5.5-6.0 22 43-46 52 delbrueckll ssp. bulga r±cus

6.0-6.5 22 37-42 49-52 thermoph±lus

Lactococcus 6.0-6.5 24-30 32-37 ssp.

Lactococcus 6.0-6.5 28-32 34-39 ssp . cremons

La ctococcus 6.0-6.5 30-34 40-42 ssp .

Leuconostoc 6.0-6.5 20-28 37 mesenteroldes ssp cremorls Table 3

0 . 5 - 0 . 7 NO YES NO

0 . 5 - 0 . YES YES NO s sp

As one can see from the data reported in Table 2 and 3 the essential lactic ferments present in the composition according to the invention are those able to associate the best growth feature at relatively low temperatures, in any case easily achievable also in homemade ice cream factories and contemporaneously are also able to produce flavours and obtain the desired sparkling degree, because they also produce carbon dioxide. Listed in the following table 4 are bacterial strains

(isolated at Centro Sperimentale del Latte S.p.A.), selected from among the species listed in table 1 and useable for preparing the mixture of milk ferments comprised in the composition according to the invention. The strains are listed per number and date of deposit carried out at the International Bank of Microrganisms BCCM™/LMG collection of the University of Gent (K. L . Ledeganckstraaat 35, B-9000 Gent, Belgium) : Table 4

When the kefir-like composition contains all the lactic ferments reported in table 1 preferably it presents the composition reported in Table 5. In this table the species Lactococcus lactis ssp. lactis, Lactococcus lactis ssp. cremoris , Lactococcus lactis ssp. lactis biovar

1 diacetylactis, Leuconostoc mesenteroides ssp. cremoris are indicated in their entirety with the term "mesophilic component " .

Table 5

In the following tables 6-9 preferred forms of realisation of the mixtures of lactic ferments reported in table 5 and contained in the compositions according to the present invention.

Table 6

Table 7

Table 8

Table 9

In the mixture of milk ferments according to table 9, the mesophilic component has a qualitative and quantitative formulation indicated in the following table 10 : Table 10

Preferably the kefir-like compositions according to the present invention are in lyophilized form.

Preferably the composition according to the present invention comprises at least one excipient such as food grade lactose. Even more preferably they comprise as the sole excipient lactose in the amounts reported in percentage by weight in the following Table 11.

Table 11

In the following table 12 a particularly preferred composition is reported selected from those reported in the previous table 11. Table 12

Even more preferably this composition presents, as far as the lactic ferments are concerned , the formulation reported in the aforesaid table 9 and as far as the mesophilic component is concerned, the formulation reported in the table 10. In this specific formulation, therefore the concentration expressed as UFC/G of the bacterial species comprised in the mixture of lactic ferments is reported in the following Table 13.

Table 13

The composition according to the invention may be used as an ingredient for producing a kefir-like fermented product, having an aromatic and particularly pleasant taste. For example, it can be used as a starter for producing kefir- like fermented milk. The starter containing the mixture of lactic ferments in lyophilised form may be packaged in mono-dose containers, for example sachets.

Preferably, each sachet contains a dose equal to 5 grams of composition wherein the of the mixture of milk ferments is equal to 0.5 grams and the remaining (4.5g)is the excipient, preferably lactose.

In order to produce fermented milk using the abovement ioned starter, a dose of composition (i.e., the content of a sachet) is poured into a container with a predetermined volume of milk, cream or a mixture of milk and cream, at a temperature comprised between 22°C and 30⁰C. After mixing the starter with the milk (or cream, or milk/cream mixture), the container is closed and the milk/starter mixture (or cr e am/ s t a r t e r , or milk/cream/starter) is incubated at a temperature of 22°-30°C for 12-24 hrs, until it reaches a predetermined pH and a desired aroma. The fermented product thus obtained is kefir-like fermented milk (or fermented cream), which may be used cold (i.e. without undergoing pasteurization) as an ingredient for preparing probiotic ice cream products, such as for example ice creams, lollipops and chilled desserts, particularly preferred is the icecream product obtained with the kefir-like fermented milk obtained with the kegfir like fermented milk onbtained using the composition according to the present invention which is added with the following base in powder form comprising in particular the following components: RECIPE OF THE BASE IN POWDER FORM FOR ICE CREAM (% BY WEIGHT) Sucrose 52

Dextrose 17

Skim milk powder 17 vegetable fats 7 Rice starch 2

Inulin 2 stabilizer (carob seed meal E410) 2

Emulsifier (sucresters E473) 1

TOTAL 100

The fermented milk or cream is added to the base in the following ratio 3 parts by weight fermented milk per 1 part by weight of the base in powder form. Therefore also in this case the ice cream presents a sucrose content being not higher than 15%by weight.

Exemplified hereinafter are probiotic ice cream products, which are prepared using - as an ingredient - a fermented kefir-like product obtained through the composition according to the invention. Example 1

A probiotic kefir ice cream (at amounts equivalent to 1 kg is obtained starting from the ingredients indicated in the following table 14.

Table 14

The ingredient indicated as "neutral component" may comprise, for example, a stabilising agent and an emulsifying agent.

The stabilising agent may comprise carob seed meal. The emulsifying agent may comprise sucrose esters (fatty acids sucrose esters).

The fermented kefir-like product is obtained by mixing a lyophilized starter with UHT cow milk. The starter consists of the composition according to table 12 as far the weight ratio between the mixture and the excipients are concerned, the composition according to table 9 as far as the amounts of the single non mesophilic components and the total mesophililic components are concerned, the composition of table 10 as far the single mesophilic species present in the mesophilic component, and the composition according to table 13 reporting the concentration of lactic ferments expressed as UFC/g of the single non mesophilic components and the total mesophilic components. After adding the starter, the milk is incubated at a temperature of 22°-30°C for a period of time sufficient to reach a pH comprised between 4.5 and 4.2.

The other components (sucrose, dextrose, whole milk powder, neutral component) are mixed together (separately with respect to the fermented kefir-like product) and pasteurised. The pasteurised mixture thus obtained is cooled and in turn mixed with the fermented kefir-like product, so as to obtain a probiotic kefir ice cream.

The percentage content - in solid substances - of the of the probiotic kefir ice cream is indicated in the following table 15:

Table 15

In table 15 (and in the subsequent tables 16, 18, 19, 21 and 22) the NFMS acronym stands for "Non-fatty milk solids" . The probiotic kefir ice cream prepared using the ingredients of table 14 has the balancing characteristics indicated in the following table 16: Table 16

The term "balancing characteristics" of an ice cream is used to describe the percentage contents of the various solid ingredients, that are selected in such a manner to mutually balance the solid substances and the liquid substances present in the ice cream, in such a manner to obtain a product having suitable organoleptic and preservation properties .

EXAMPLE 2

A kefir probiotic ice cream (amounting to 1 kg) is obtained starting from the ingredients indicated in the following table 17:

Table 17

The ingredient referred to as "neutral component" is similar to the neutral component described in Example 1.

The procedure for preparing the fermented kefir-like product and the probiotic kefir ice cream is identical to the preparation procedure described in example 1. The percentage content - in solid substances - of the probiotic kefir ice cream is indicated in the following table 18:

Table 18

The probiotic kefir ice cream prepared using the ingredients of table 17 has the balancing characteristics indicated in the following table 19:

Table 19

Example 3

A probiotic kefir ice cream (amounting to 1 kg) is obtained starting from the ingredients indicated in the following table 20:

Table 20

The ingredient indicated as "neutral component" is analogous to the neutral component described in Example 1.

The procedure for preparing the fermented kefir-like product and the probiotic kefir ice cream is identical to the preparation procedure described in Example 1. The qualitative and quantitative percentage formula of the solid substances present in the probiotic kefir ice cream is indicated in the following table 21:

Table 21

The probiotic kefir ice cream prepared using the ingredients of table 20 has the balancing characteristics indicated in the following table 22:

Table 22

EXAMPLE 4

An ice cream is prepared by adding to the kefir-like fermented milk prepared as described in Example 1 the following base in powder form:

Sucrose 52

Dextrose 17

Skim milk powder 17 vegetable fats 7 Rice starch 2

Inulin 2 stabilizer (carob seed meal E410) 2

Emulsifier (sucresters E473) 1

TOTAL 100

in the following weight ratio 3 parts by weight of fermented milk : 1 part by weight of the base.

Claims

1. A composition suitable for preparing a kefir-like fermented product comprising as fermentation microorganisms only a mixture of milk ferments comprising: a) Lactobacillus acidophilus, b) Lactobacillus casei ssp. casei, and the following lactic mesophilic ferments: c) Lactococcus lactis ssp. lactis biovar diacetylactis_r d) Leuconostoc mesenteroides ssp. cremoris

2. The composition according to claim 1 wherein said mixture of lactic ferments further comprises at least one lactic ferment selected from the group consisting of: Lactobacillus delbrueckii ssp. bulgaricus, Streptococcus thermophilus, and the lactic ferments of mesophylic type: Lactococcus lactis ssp. lactis, Lactococcus lactis ssp. cremoris.

3. The composition of claim 2 comprising besides all the lactic ferments (a) , (b) , (c) and (d) , all the lactic ferments listed in claim 2.

4. The composition according to claim 2 or 3 wherein the mixture of lactic ferments consists of the following components in % by weight referred to the total composition weight:

6. Composition according to claim 5 comprising

7. Composition according to claim 5 or 6 wherein said mesophilic component consists of the following components in percentage by weight calculated on the total weight of said mesophilic component:

Lactococcus lactis ssp. lactis 60 Lactococcus lactis ssp. cremoris 20 Lactococcus lactis ssp. lactis biovar diacetylactis 10 Leuconostoc mesenteroides ssp. cremoris 10

8. The composition according to any one of the preceding claims wherein said lactic ferments are present in lyophilized form.

9. The composition according to anyone of the preceding claims, comprising at least one excipient .

10. The composition according to claim 9, comprising fro 80 to 95% of said excipient and from 5 to 20% by weight of milk ferments, said percentages being referred to the total composition weight.

11. The composition according to claim 11, comprising at least one excipient in percentage by weight equal to 90% and these lactic ferments in percentage by weight equal to 10% by weight, based on the total composition weight.

12. The composition according to claim 11 wherein the lactic ferments are present in the amounts according to claim 6 and the me^'sophilic components consists of the lactic ferments present in the amounts according to claim 7 said lactic ferments presenting the following concentrations expressed in UFC/g:

Lactobacillus acidophilus 50 x 10⁹

Lactobacillus casei ssp. casei 50 x 10⁹

Lactobacillus delbrueckii ssp. bulgaricus 10 x 10⁹ Streptococcus thermophilus 200 x 10⁹

Mesophilic component 200 x 10⁹

13. The composition according to claim 1 wherein:

(a) comprises at least one strain selected from LMG P- 21904 and LMG P-17503, - (b) is the strain Lactobacillus easel ssp. easel LMG P-17504,

- (c) comprises at least one strain Lactococcus lactis ssp. lactis biovar diacetylactis selected from the group consisting of: Lactococcus lactis ssp. lactis biovar diacetylactis LMG P-24648, Lactococcus lactis ssp. lactis biovar diacetylactis LMG P-24649, Lactococcus lactis ssp. lactis biovar diacetylactis LMG P-24650,

(d) comprises at least one strain selected from the group consisting of: Leuconostoc mesenteroides ssp. cremoris LMG P - 24646 and Leuconostoc mesenteroides ssp. cremoris LMG P -24647

14. Composition according to claim 2, wherein:

- Lactobacillus delbrueckii ssp. bulgaricus is Lactobacillus delbrueckii ssp. bulgaricus LMG P -21905,

Streptococcus thermophllus is selected from the class consisting of: Streptococcus thermophllus

LMG P-21908, Streptococcus thermophllus LMG P-

24652 and Streptococcus thermophllus LMG P —

24653,

- Lactococcus lactis ssp. lactis is Lactococcus lactis ssp. lactis LMG P - 24651/

- Lactococcus lactis ssp. cremoris is selected from: Lactococcus lactis ssp. cremoris LMG P - 24643 Lactococcus lactis ssp. cremoris LMG P — 24644 Lactococcus lactis ssp. cremoris LMG P — 24645.

15. Starter of fermentation comprising the composition according to any preceding claims .

16. Ingredient for food product, comprising a composition according to anyone of claims 1-14.

17. Kef ir— like fermented milk obtained by fermentation utilizing the composition according to any preceding claims 1-14.

18. Kefir-like fermented cream obtained by fermentation utilizing the composition according to any preceding claims 1—14.

19. Ice cream product containing the fermented milk according to claim 17 or the cream according to claim 18.

20. Ice cream product according to claim 19, obtained with the fermented milk according to claim 17, by adding the following base in powder form containing in particular the following components expressed as % by weight on the total weight of said base:

Sucrose 52 Dextrose 17

Skim milk powder 17 vegetable fats 7

Rice starch 2

Inulin 2 stabilizer ( carob seed meal E410 ) 2 in the following weight ratio 3 parts by weight of fermented milk : 1 part by weight of said base in powder form .

21. Filler for cold confectionery according to claim 17 comprising the fermented milk according to claim 17 and

/or the fermented cream according to claim 18.