Manufacture of strained fermented dairy products

Abstract

The invention relates to the manufacture of strained fermented dairy products. The invention allows improvements in the use of the materials and by-products as well as in the properties of the product obtained. A lactic acid bacteria having a low lactose metabolization capacity in acid whey is used.

Claims

1. A process for manufacturing a strained fermented dairy product, comprising: a) heating a dairy material comprising lactose, b) fermenting with lactic acid bacteria comprises at least three of strain CNCM I-2784, strain CNCM I-2835, strain CNCM I-2773, and strain CNCM I-2787, c) separating to obtain a strained fermented dairy product and an acid whey by-product comprising lactose, wherein the acid whey by-product comprises: 92.0% to 95% water by weight, 2.80% to 4.7% lactose by weight, 0.1% to 0.4% protein by weight, at least one lactic acid having a low lactose metabolization capacity, wherein the lactose has a stability that is higher than 85% during 7 days of storage at 32 C., and d) heating at a temperature of from 50 C. to 75 C. to thermoshock the acid whey by-product, wherein the heating to a temperature of from 50 C. to 75 C. stabilizes a plurality of organoleptic properties associated with the strained fermented dairy product to form at least one valorization, wherein the heating to a temperature of from 50 C. to 75 C. preserves the lactic acid bacteria comprising the at least three of strain CNCM I-2784, strain CNCM I-2835, strain CNCM I-2773, and strain CNCM I-2787, wherein the heating to a temperature of from 50 C. to 75 C. extends a shelf-life of the acid whey by-product for 15 days and capable of oral administration.

2. The process according to claim 1, wherein the at least three of strains include the lactic acid bacteria is strain CNCM I-2787.

3. The process according to claim 1, wherein: the lactic acid bacteria 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 strain CNCM I-2787.

4. The process according to claim 1, wherein: heating step a) is performed at a temperature of from 80 C. to 99 C., fermenting step b) is performed at a temperature of from 30 C. to 45 C., and/or separation step c) is performed at a separation temperature of from 30 C. to 45 C.

5. The process according to claim 1, comprising a homogenization step before or after the heating step a).

6. The process according to claim 1, wherein at step c) an amount of from 10% to 30% by weight, with reference to the amount of dairy material, of acid-whey by-product is recovered.

7. The process according to claim 1, further comprising a smoothing step e), wherein the smoothing step e) is a dynamic smoothing step including agitation and/or shear.

8. The process according to claim 7, comprising at least one cooling step f), wherein the at least one cooling step f) comprises: f1) cooling the fermented dairy product, and/or f2) cooling the acid whey by-product.

9. The process according to claim 8, comprising the at least one cooling the step f1) wherein cooling is performed to a temperature of from 4 C. to 10 C.

10. The process according to claim 8, comprising the at least one cooling step f2) wherein cooling is performed to a temperature of from 15 C. to 25 C.

11. The process according to claim 1, wherein the heating step d) is performed at a temperature of from 50 C. to 60 C.

Description

EXAMPLES

Example 1Manufacture of Strained Fermented Dairy Products and Acid Whey By-Products

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

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

Example 2Acid-Whey

(3) The acid whey is collected as aliquot to sterile specimen cups. Separate samples are collected: A reference sample which is aliquot and immediately frozen by placing it in a chamber to stop any lactose metabolization, A 32 C. storage sample which is aliquot and placed in a 32 C. chamber, A 4 C. storage sample which is aliquot and placed in a 4 C. chamber,

(4) 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.

(5) Acid Whey Analysis

(6) The lactose content and Streptococcus bacteria populations are analyzed (National Food Lab, Livermore, California).

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

(8) 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

(9) This shows that Culture 2 allows higher conservation of lactose in acid whey.

(10) TABLE-US-00002 TABLE 2 Remaining S. thermophilus Lactose lactose (%) (CFU/g) 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* 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

(11) 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 3Strained Fermented Dairy Product

(12) 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.

(13) 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.

(14) 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.

(15) 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.

(16) 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)

(17) 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 4Post-Acidification

(18) 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.

(19) TABLE-US-00004 TABLE 4 Plain Product Plain Product with Culture 1 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

(20) 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.