ACID WHEY WITH STABLE LACTOSE CONTENT

Abstract

The invention relates to improved acid whey compositions, having an improve lactose content and stability. The invention also relates to processes of making such compositions.

Claims

1. An acid whey composition comprising lactose and lactic acid bacteria, wherein: the lactose content is of at least 3.20% by weight, the lactic acid bacteria are at least partly in an alive state, the lactose stability is of higher than 85%, during a storage of 7 days at 32? C.

2. The acid whey according to claim 1, wherein the lactose stability is of higher than 90%.

3. The acid whey according to claim 1, having a pH of from 3.50 to 4.70.

4. The acid whey according to claim 1, having: from 0.0% to 0.4% of protein, from 3.20% to 4.70% of lactose, and from 92.0% to 95.0% of water.

5. The acid whey according to claim 1, wherein the lactic acid bacteria comprise at least one lactic acid bacteria having a low lactose metabolization capacity is the acid whey.

6. A process for the manufacture of an acid whey composition according to claim 1, comprising: a) heat treatment of a dairy material comprising lactose, b) fermentation with lactic acid bacteria, and c) separation to obtain a strained fermented dairy product and the acid whey composition comprising lactose.

7. A process according to claim 6, wherein the lactic acid bacteria comprise at least one lactic acid bacteria having a low lactose metabolization capacity in the acid whey.

8. The process according to 7, wherein the at least one lactic acid bacteria comprises a Lactobacillus bulgaricus strain.

9. The process according to claim 6, wherein the fermentation step b) is carried out with a culture comprising at least one Streptococcus thermophilus strain and at least one Lactobacillus bulgaricus strain.

10. The process according to claim 8, wherein the Lactobacillus bulgaricus strain is strain CNCM I-2787.

11. The process according to claim 10, wherein: the at least one Streptococcus thermophilus strain comprises at least one Streptococcus thermophilus strain selected from the group consisting of strain CNCM I-2784, strain CNCM I-2835, strain CNCM I-2773 and mixtures or associations thereof, and the Lactobacillus bulgaricus strain is strain CNCM I-2787.

12. The process according to claim 6, wherein: step a) is performed at a temperature of from 80? C. to 99? C., step b) is performed at a temperature of from 30? C. to 45? C., and/or step c) is performed at a temperature of from 30? C. to 45? C.

13. The process according to claim 6, comprising a homogenization step before or after the heat treatment step a).

14. The process according to claim 6, wherein at step c) an amount of from 10% to 30% by weight, with reference to the amount of dairy material, of acid-whey composition is recovered.

15. The process according to claim 6, comprising at least one cooling step, wherein the at least one cooling step comprises: e1) cooling the fermented dairy product, and/or e2) cooling the acid whey composition.

16. The process according to claim 15, comprising the at least one cooling step e2) wherein cooling is performed to a temperature of from 15? C. to 25? C.

17. The process according to claim 6, wherein a thermoshocking heat treatment step at a temperature of from 50? C. to 75? C. is performed: between the fermentation step b) and the separation step c), or after the separation step c), on the acid whey composition.

18. The process according to claim 17, wherein thermoshocking heat treatment step is performed at a temperature of from 50? C. to 60? C.

19. A process of using the acid whey composition according to any of claims 1 comprising valorizing to lactose comprised therein.

20. A process according to claims 19, wherein the valorization is: Isolation and purification of lactose to produce crystalline lactose, Transformation of lactose into glucose, galactose or other sugars through enzymatic treatments, Transformation of lactose into polysaccharides through enzymatic treatments, Utilization as a medium to grow biomass with micro-organisms, or Fermentation with yeasts to produce ethanol.

Description

EXAMPLES

Example 1

Manufacture of Strained Fermented Dairy Products and Acid Whey By-Products

[0118] Strained fermented dairy products are manufactured at pilot scale with using the following ingredients: [0119] Milk: Skimmed milk having 3.17% protein, 0% fat and 8.8% dry matter [0120] Cultures: [0121] Culture 1: Yo-Mix? 495, marketed by Dupont [0122] Culture 2: Mixture of the following bacterial strains: Streptococcus thermophilus [0123] DN-001640, Streptococcus thermophilus DN-001336, Streptococcus thermophilus [0124] DN-001236, and Lactobacillus bulgaricus DN-100290.

[0125] The procedure involves the following steps: [0126] heat treatment of milk at a temperature of 95? C. during 6.5 minutes, [0127] homogenization at a temperature of 60? C., at a pressure of 69 bars, [0128] inoculation of milk at 40? C. with 0.02% by weight of culture, [0129] fermentation at a temperature of 40? C. to reach a breaking pH of 4.65, [0130] optionally: temperature increase (fermented mix thermoshock) to a temperature of 59.5? C. during 2.5 minutes, [0131] separation, at a temperature of 41.5? C., of 72% of whey, with a Westphalia KNA3 pilot scale centrifuge separator, to obtain: [0132] A) a strained fermented dairy product, and [0133] B) an acid whey by-product, and [0134] dynamic smoothing, performed on the strained fermented dairy product.

Example 2

Acid-Whey

[0135] The acid whey is collected as aliquot to sterile specimen cups. Separate samples are collected: [0136] A reference sample which is aliquot and immediately frozen by placing it in a chamber to stop any lactose metabolization, [0137] A 32? C. storage sample which is aliquot and placed in a 32? C. chamber, [0138] A 4? C. storage sample which is aliquot and placed in a 4? C. chamber, [0139] An Acid whey thermoshock sample which is heat treated at 58? C. during 2.5 minutes using a metal beaker and a hot plate, and then aliquot and placed in a 4? C. chamber.

[0140] All acid whey samples are kept in their respective chambers for 7 days before they are frozen in the ?4? C. chamber and then analyzed within 24 hours of chamber transfer.

Acid Whey Analysis

[0141] The lactose content and Streptococcus bacteria populations are analyzed (National Food Lab, Livermore, Calif.).

[0142] Lactose analysis results are reported on tables 1 and 2 below: [0143] Remaining lactose in the acid whey (g of lactose per 100 g of acid whey) [0144] Steptococcus thermophilus count (CFU per g) [0145] Lactose loss, compared to the reference sample: [0146] Lactose loss=(sample value?reference reference)/reference value Here a negative value indicates a loss.

TABLE-US-00001 TABLE 1 Culture 1 Culture 2 32? C. Storage 3.16 3.87 Remaining lactose (%) 32? C. Storage ?22% ?6.5% Lactose loss Acid whey thermoshock <?2% ?1.0% Lactose loss

[0147] This shows that Culture 2 allows higher conservation of lactose in acid whey.

TABLE-US-00002 TABLE 2 Remaining S. thermophilus lactose (%) (CFU/g) Lactose Loss Culture 1 4? C. Storage 3.81 6.0 ? 10{circumflex over ()}7 ?6% 32? C. Storage 3.16 9.6 ? 10{circumflex over ()}6 ?22% Culture 2* Acid whey 3.98 6.9 ? 107 ?1.0% thermoshock 4? C. Storage 3.87 1.4 ? 10{circumflex over ()}8 ?3.5% 32? C. Storage 3.76 8.0 ? 10{circumflex over ()}3 ?6.5% * average on 2 productions

[0148] As there is a CFU count (Colony Forming Units) is shows that at least part of the lactic acid bacteria are alive, even after a thermoshock treatment. As the lactose loss is reduced with this treatment, it suggests that this treatment places the bacteria into an alive form with reduced lactose metabolism.

[0149] Under 32? C. chamber conditions, the highest level of biomass available is found with Culture 2. Interestingly and surprisingly, Culture 2 also has the lowest level of lactose at those conditions which means a lesser amount of biomass is needed to consume lactose. This shows that a culture selection can play a role in the stabilization of lactose in the acid whey.

Example 3

Strained Fermented Dairy Product

[0150] The strained fermented dairy products, also referred to as White Mass (WM), are processed as finished products. For plain products 6 oz of White Mass are conditioned in cups.

[0151] For Strawberry Fruit On the Bottom (FOB) products, 2 oz (25%) of a strawberry preparation and then 4 oz (75%) of White Mass are dosed in a cup.

[0152] The products obtained with Culture 1 and with Culture 2 are compared for overall balance by a trained panel, at D28 (28 days of storage at 4? C. after preparation) and D55 (55 days of storage at 4? C. after preparation). Most significant and important differences in attributes are reported on table 3 below.

[0153] Overall balance attributes: Evaluation of the roundness of flavor, of the lack of spike from any tastes or flavor, and of the lack of overpowering notes

TABLE-US-00003 TABLE 3 Culture 2, with reference to Culture 1 Plain Product D28 More overall balance (score difference 0.6) Plain Product D55 More overall balance (score difference 0.8) Strawberry FOB Product D28 More overall balance (score difference 0.6) (stirred before tasting) Strawberry FOB Product D55 More overall balance (score difference 0.6) (stirred before tasting)

[0154] These results show that the products obtained with Culture 2 have an improved overall balance, and that the difference is even higher for the White Mass part after an extended shelf-life of 55 days.

Example 4

Post-Acidification

[0155] The post-acidification of the white mass is evaluated by pH measurements at D0 (after preparation), and D7 (7 days of storage at 4? C. after preparation). The results are reported on table 4 below.

TABLE-US-00004 TABLE 4 Plain Product with Culture 1 Plain Product with Culture 2 pH at D0 4.50 4.45 pH at D7 4.45 4.40 Loss of pH from ?1.1% ?1.1% D0 to D7

[0156] This shows that the post-acidification of the strained fermented dairy product is similar with Culture 1 (pH drop of 1.1%) and Culture 2 (pH drop of 1.1%). However, surprisingly, the lactose stability in the corresponding acid whey by-products it very different with Culture 1 (lactose loss of 22%) and Culture 2 (lactose loss of 6.5%), as shown on table 1 and table 2. This shows that the lactose metabolization capacity of the cultures in acid whey is not directly correlated to post-acidification capacity in the strained fermented dairy product.