LEAVEN

Abstract

This product based on leaven comprises a package containing living leaven closed with a gas tight seal. The leaven is in a nitrogen atmosphere.

Claims

1. A product consisting of leaven or the like, living, having a percentage by weight of dry material of less than 90%, characterised in that the product is contained in an atmosphere of nitrogen with a purity of greater than 97% by volume in a package of a material with a high gas barrier and with a gas tight seal.

2. A product according to claim 1, characterised in that the packaging material has a permeability coefficient to O.sub.2 of less than 10 cm.sup.3/m.sup.2/24 h.

3. A product according to claim 1, characterised in that the packaging material is a barrier to water vapour.

4. A product according to claim 1, characterised in that the material consists of one or more layers of PVDC, OPA, EVOH or aluminium or a mixture of these.

5. A product according to claim 1, characterised in that the material consists of glass, silica and/or aluminium.

6. A product according to claim 1, characterised in that the material is anti-UV.

7. A process of manufacturing the product claim 1, characterised in that the living leaven or the like, is placed in a container made of a gas barrier material in an atmosphere of more than 97% pure nitrogen by volume and the container is closed with a gas tight seal.

8. A process according to claim 7, characterised in that nitrogen with a purity of between 99 and 100% by volume is used.

9. A product according to claim 1, wherein the purity of nitrogen is between 99 and 100% by volume.

10. A method for keeping lactic bacteria in leaven in a cultivable state comprising packaging leaven in a package of a material with gas barrier filled with nitrogen with a purity greater than 97% by volume and tightly sealing the package.

11. The method of claim 10, wherein the purity of nitrogen is between 99% and 100% by volume.

12. The method of claim 10, wherein the material has a permeability coefficient to O.sub.2 of less than 10 cm.sup.3/m.sup.2/24 h.

13. A method for maintaining the content of unsaturated fatty acids in leaven comprising packaging leaven in a package of a material with gas barrier filled with nitrogen with a purity greater than 97% by volume and tightly sealing the package.

14. The method of claim 13, wherein the purity of nitrogen is between 99% and 100% by volume.

15. The method of claim 13, wherein the material has a permeability coefficient to O.sub.2 of less than 10 cm.sup.3/m.sup.2/24 h.

Description

EXAMPLE NO. 1

[0032] 500 g of wheat germ leaven whose MS was 32.5% (fresh living leaven) were packaged in a PET pack coated with PVDC-PE with a permeability coefficient to O.sub.2 of <10 cm.sup.3/m.sup.2/24 h.bar, in a protective atmosphere consisting of 100% nitrogen (MESSER (manufacturer's trade name)) for food use in accordance with CE rule no. 1333/2008. The packaging was done using a compensated vacuum jar CON (manufacturer's trade name) series BORA 550 Dual Gas according to the following the parameters: 8 seconds pulling vacuum, 8 seconds injection of gas at a pressure of 3 bar, 5 seconds heat sealing. The volume occupied by the protective atmosphere (head space) represented 40% of the total volume in the pack.

[0033] The packed leaven was then kept in a classical cold chamber at a temperature of 4-6 C. in a normal air atmosphere (consisting of about 20 to 21% O.sub.2).

EXAMPLE NO. 2: COMPARATIVE

[0034] 5kg of wheat germ leaven with a MS of <32.5% % (fresh living leaven) was packed in a polypropylene bucket with a permeability coefficient to O.sub.2 of 40 cm.sup.3/m.sup.2/24 h.bar. The packaging was carried out under normal air conditions, no protective atmosphere, nor placing under vacuum was applied. The volume of the head space in the bucket was 20% of the total volume of the bucket. The leaven in the bucket was then kept in a classical cold chamber at a temperature of 4-6 C. in a normal air atmosphere (consisting of about 20 to 21% O2).

[0035] The dry material (MS) was measured by the infrared method with a Radwag (manufacturer's trade name) halogen dessiccator model MAC 50/1. Three measurements were made for 2.00.1 g of the product, then averaged. The analysis program applied a temperature of 130 C. until the weight changed by 1 mg in 25 s. The values were expressed as a percentage of MS contained in the leaven or the like.

[0036] The gaseous composition in O.sub.2 and CO.sub.2 of the head space was measured with an Oxybaby (manufacturer's trade name) O.sub.2/CO.sub.2 model 6.0 analyser (WITT). For each measurement point, two packs were analysed by the destructive method (puncturing the package and analysing the gas in the head space of the pack).

[0037] For example 1: the colour was measured for the leaven previously homogenised in the pack (by manual pressure on the pack).

[0038] For example 2: a sample was taken of the leaven contained in the PP bucket. 50 g of the top layer of the leaven in contact with the head space (about 2 cm in height) were taken and 50 g of the lower layer then they were mixed. The colour measurement was made on this mixture.

[0039] Results in Table 1

TABLE-US-00001 Example 1 Example 2 Residual level of 3 days 1.2 O.sub.2 in the head 0.5 months 0.1 space (in %) 1 months 0 1.5 Months 0.4 Colour parameter L* 3 days 67.16 65.59 0.5 months 67.93 43.46 1 months 68.08 46.44 1.5 months 68.11 44.91 Colour parameter a* 3 days 4.12 2.72 0.5 months 4.08 0.88 1 months 4.36 1.23 1.5 months 4.32 0.84 Colour parameter b* 3 days 20.83 19.01 0.5 months 20.32 2.12 1 months 20.67 0.5 1.5 months 20.92 0.87

[0040] The results obtained show that in example 1 the residual level of oxygen inside the package was <2%, as recommended in the invention, and that that is sufficient to maintain a stable colour throughout the preservation of the leaven. There were only small variations in the colorimetric parameters L*a*b*, as the leaven retained its original light brown colour.

[0041] On the other hand, in example 2 the atmosphere in the package was not changed, the head space therefore consisted of normal air during packaging (the air consisting of 20-21% O2) and the PP bucket was not an adequate barrier to oxygen. This was translated into a significant change in the colouring (brown/black) of the leaven during preservation), mainly for the colorimetric parameter L* whose measurement exceeded 65.59 (fairly light leaven) at 44.91 after 1.5 months storage (leaven very dark grey/black). The leaven also changed towards green and blue for the parameters a* and b.

[0042] Examples 3A and 3C (Comparative) and 3B According to the Invention:

[0043] Tests Conducted in Air or Hydrogen Compared with Nitrogen:

[0044] 500 g of wheat germ leaven with an MS of 32.5% by weight (fresh living leaven) were packed in an OPP/PE-EVOH-PE pack whose permeability coefficient to O2 is 2 cm3/m2/24 h.bar in an unmodified atmosphere consisting of air (example 3A) or in a modified atmosphere consisting of 100% nitrogen (MESSER (manufacturer's trade name)) (example 3B) or consisting of 4.5% H2/95.5% N2 (LINDE (manufacturer's trade name) (example 3C). Packing was carried out with a compensated CCM (manufacturer's trade name) vacuum jar series BORA 550 Dual Gas according to the following parameters: 8 seconds pulling vacuum, 8 seconds injection of gas at a pressure of 3 bar, then 3 or 4 seconds heat sealing.

[0045] The volume occupied by the protective atmosphere (head space) represented 40 to 50% of the total volume in the pack.

[0046] The packed leaven was then kept in a classical cold chamber at a temperature of 4-6 C. in an atmosphere of normal air (containing about 20 to 21% O2).

[0047] The leaven was monitored for 8 weeks, in particular the gaseous composition of the head space in the packs, the colour of the leaven, its composition in lactic bacteria and its composition in fatty acids.

[0048] Changes in Gaseous Composition

TABLE-US-00002 Storage Level Level Other gases = time in of O2 of CO2 level of N2 weeks in % in % or N2 + H2 In air 0 21.13 0.4 78.5 (3A) 0.5 19.1 5.4 75.5 1 18.4 7.3 74.3 2 17 8.2 74.8 3 16.1 11.1 72.8 4 20.3 2.4 77.3 6 9.1 13.5 77.4 8 12.5 5.2 82.3 In 100% N2 0 0.33 0.5 99.2 (3B) 0.5 2.3 2.8 94.9 1 0.5 7.1 92.4 2 1.4 6.3 92.3 3 0.4 13.3 86.3 4 1 9.7 89.3 6 0.6 9.6 89.8 8 0.6 7.4 92 In 4.5% H2 + 0 0.2 0.2 99.6 95.5% N2 0.5 0 4.2 95.8 (3C) 1 1.4 7.9 90.7 2 0.1 5.2 94.7 3 0 9.2 90.8 4 0.5 10.6 88.9 6 1.2 10.4 88.4 8 0.5 7.4 92.1

[0049] The results obtained showed that the levels of residual oxygen inside the packs in a modified protective atmosphere of 100 % N2 or 4.5% H2/95.5% N2 complied with the recommendations of the invention. These are <5% residual O2 and predominantly <2% residual O2, while the packs packed in air showed residual levels of O2 in the head space in the pack of >9%, mostly >15% O2.

[0050] Leaven being a living product, the microorganisms, lactic bacteria and yeasts it contains have their metabolic activity greatly slowed down but not totally deactivated.

[0051] This may explain the production of CO2 in the packs in a protective atmosphere due to the fermentation metabolism of the microflora. In air, part of the oxygen was also consumed by the microorganisms.

[0052] Change in Colour

TABLE-US-00003 Storage time in weeks L* a* b* In air 0.5 61.65 2.13 16.72 1 57.29 0.14 11.31 2 59.76 0.88 14.52 3 56.21 0.21 10.13 4 56.45 0.27 20.42 6 56.73 0.09 11.28 8 54.25 0.08 9.15 In 100% 0.5 62.43 2.86 17.89 N2 1 62.55 3.16 18.38 2 63.85 3.86 19.72 3 63.29 3.61 18.89 4 63.24 3.42 18.75 6 62.58 3.39 18.74 8 62.78 3.89 18.86 In 4.5% 0.5 63.4 4.22 20.77 H2 + 1 63.63 4.04 19.92 95.5% N2 2 64.23 4.22 20.25 3 64.03 4.19 19.85 4 64.07 4.19 20.17 6 63.96 4.26 20.22 8 62.26 3.84 18.73

[0053] The modified 10.0% N2 and 4.5% H2/95.5% N2 atmospheres had an equivalent effect on the colour of the leaven. Both of them permitted the colour properties of the leaven to be retained, thus preventing oxidation of the leaven, while there was a significant change in colour in air. The diagram above shows the effect on colour parameter L* in the L*a*b * system in which the value reduces rapidly as shown by colouration of the leaven which tends significantly to black, making the leaven unfit for sale, while in the 100% N2 and 4.5% H2/95.5% N2 modified atmospheres the parameter L* remained stable, like the ether parameters a* and b*.

[0054] Change in the Lactic Microflora

TABLE-US-00004 Level of lactic bacteria in log (ufc)/g In 4.5% Number In 100% H2 + of weeks In air N2 95.5% N2 0.5 7.11 7.65 7.58 1 7.38 7.48 7.62 2 7.32 7.00 7.30 3 7.52 7.40 7.30 4 5.30 7.18 6.78 6 4.04 6.85 5.08 8 4.85 6.96 5.28

[0055] Change in the Fatty Acids Content

TABLE-US-00005 Storage Profile of fatty acids in % Difference from t0 time in Total MG AG AG mono- AG poly- AG AG mono- AG poly- weeks g/100 g saturated unsaturated unsaturated saturated unsaturated unsaturated Before 0 3.5 +/ 0.5 18.9 14.8 66.3 packing 100% N2 2 wks 3.8 +/ 0.6 19.82 15.92 64.15 +0.92 +1.12 2.15 H2 + N2 3.4 +/ 0.6 25.98 14.46 59.56 +7.08 0.34 6.74 100% N2 4 wks 3.5 +/ 0.6 18.7 15.16 66.14 0.2 +0.36 0.16 H2 + N2 3.5 +/ 0.6 23.19 12.45 64.36 +4.29 2.35 1.94 MG: fatty materials AG: Fatty acids

[0056] The modified 4.5% H2/95.5% N2 atmosphere impacted the profile of the fatty acids in the leaven by increasing the composition in saturated fatty acids and proportionately reducing the composition in unsaturated fatty acids while packaging in 100% N2 completely stabilised the composition in fatty acids in the leaven.

[0057] Saturated fatty acids are lipids with no double link in their chemical structure. In foods, they are mainly found in products of animal origin (butter, meats, etc), while unsaturated fatty acids have one or more double links in their structure and are found mainly in oily fish and foods of vegetable origin, as is the case with wheat leaven in this example. Unsaturated fatty acids are to be preferred in foods as they are recognised for their beneficial effects on health, in particular for their contribution to healthy functioning of the cardiovascular system.

[0058] Packaging in 100% N2 acording to the invention, thus allows the nutritional properties of leaven to be well preserved, while an atmosphere containing hydrogen tends to encourage transformation into saturated fatty acids.

[0059] Unexpectedly, packaging in nitrogen not only preserves the intrinsic characteristics of leaven (colour, physico-chemical and nutritional composition), but also prolongs the life of its microflora, in particular preserving the longest living lactic bacteria, compared with classical packaging in air.