Method of producing a fermented milk product with improved control of post acidification

Patent metadata

Field	Value
Publication number	US-10813367-B2
Application number	US-201515317682-A
Country	US
Kind code	B2
Filing date	Jun 18, 2015
Priority date	Jun 19, 2014
Publication date	Oct 27, 2020
Grant date	Oct 27, 2020

Abstract

The present invention provides methods of producing a fermented milk product comprising a step wherein milk is fermented, wherein: (a) the fermentation is initiated by a starter culture, which starter culture comprises lactic acid bacteria capable of metabolizing one or several carbohydrates present in the milk, (b) the fermentation is terminated by a decrease of the concentration of the one or several carbohydrates during fermentation, and (c) the decrease is at least also caused by the metabolic activity of the lactic acid bacteria. The invention further provides respective methods comprising a step, wherein at least part of the whey is separated from the fermented milk product.

First claim

The invention claimed is:

1. A method of producing a fermented milk product with a stable pH, comprising:
(a) initiating milk fermentation by adding to milk a starter culture comprising lactose -deficient lactic acid bacteria capable of metabolizing one or more fermentable carbohydrates other than lactose, wherein the lactose-deficient lactic acid bacteria comprise lactose-deficient Streptococcus thermophilus that has completely lost the ability to use lactose as a source for cell growth or maintaining cell viability, and lactose-deficient Lactobacillus delbrueckii subsp. bulgaricus , and wherein the milk comprises one or more fermentable carbohydrates other than lactose metabolized by the lactose-deficient lactic acid bacteria, and
(b) fermenting the milk at a temperature between 22° C. and 45° C., wherein termination of the milk fermentation and the pH value of the fermented milk product at the termination of milk fermentation are controlled by the concentration of the one or more fermentable carbohydrates other than lactose present in the milk, and the milk fermentation terminates when the concentration decreases to a level that can no longer be metabolized by the lactose-deficient lactic acid bacteria to produce a significant amount of lactic acid, wherein the decrease is at least partly caused by the lactic acid bacteria metabolizing the one or more fermentable carbohydrates,
thereby obtaining a fermented milk product with a stable pH.

2. The method of claim 1 , wherein the pH of the fermented milk product is stable such that, upon storage at the fermentation temperature for 20 hours after termination of fermentation, the pH is maintained within a range of 0.3 pH units.

3. The method of claim 1 , wherein the pH of the fermented milk product is stable such that, upon storage at the fermentation temperature for 20 hours after termination of fermentation, the pH is maintained within a range of 0.1 pH units.

4. The method of claim 1 , wherein the milk comprises lactose at a concentration of from 5 to 100 mg/g at the start of the fermentation.

5. The method of claim 1 , further comprising packaging the fermented milk product at a temperature between 15 and 45° C.

6. The method of claim 1 , wherein the lactose-deficient lactic acid bacteria are not capable of metabolizing lactose and wherein, prior to adding the starter culture, the milk comprises fermentable carbohydrates that can be metabolized by the lactic acid bacteria at a total concentration of below 45 mg/g.

7. The method of claim 1 , wherein the fermentation is carried out in the presence of lactase at an initial concentration of 500 to 5000 NLU/1.

8. The method of claim 1 , wherein the fermentation temperature is between 30 and 45° C.

9. The method of claim 1 , wherein the pH of the fermented milk product is stable such that upon storage after termination of fermentation for a period of 6 months, the pH is maintained within a range of 0.3 pH units.

10. The method of claim 1 , further comprising at least partly separating whey from the fermented milk product, wherein the pH of the fermented milk product prior to separating whey is stable such that, upon storage, processing or maintenance at the fermentation temperature after termination of fermentation for 20 hours, the pH is maintained within a range of 0.3 pH units.

11. The method of claim 10 , wherein the pH of the fermented milk product prior to separating whey is stable such that, upon storage, processing or maintenance at the fermentation temperature after termination of fermentation for 20 hours, the pH is maintained within a range of 0.1 pH units.

12. A fermented milk product obtained by the method of claim 1 .

13. The fermented milk product of claim 12 , wherein the fermented milk product is a yoghurt, a fruit yoghurt, a yoghurt beverage or a cheese.

14. The method of claim 1 , wherein the pH of the fermented milk product is stable such that upon storage after termination of fermentation for a period of 12 months, the pH is maintained within a range of 0.3 pH units.

15. The method according to claim 1 , wherein the one or more fermentable carbohydrates other than lactose comprises one or more selected from sucrose, galactose and glucose.

16. The method according to claim 1 , wherein the one or more fermentable carbohydrates other than lactose comprises sucrose.

17. The method according to claim 1 , further comprising adding to the milk the one or more fermentable carbohydrates other than lactose.

18. The method according to claim 1 , further comprising adding sucrose to the milk.

19. The method according to claim 1 , wherein the milk fermentation terminates when the concentration of the one or more fermentable carbohydrates other than lactose decreases to within a range from 5 mg/g to 0.01 mg/g.

20. The method of claim 1 , wherein the lactose-deficient Streptococcus thermophilus strain is selected from:
(i) the strain deposited with Deutsche Sammlung von Mikroorganismen and Zellkulturen GmbH (DSMZ) under accession no. DSM 28952; and
(ii) the strain deposited with DSMZ under accession no. DSM 28953.

21. The method of claim 1 , wherein the lactose-deficient Streptococcus thermophilus strain is the strain deposited with DSMZ under accession no. DSM 28952.

22. The method of claim 1 , wherein the lactose-deficient Streptococcus thermophilus strain is the strain deposited with DSMZ under accession no. DSM 28953.

23. The method of claim 1 , wherein the lactose-deficient Lactobacillus delbrueckii ssp. bulgaricus strain is the strain deposited with DSMZ under accession no. DSM 28910.

Assignees

• Chr Hansen As

Inventors

• Garrigues Christel
• Gilleladen Christian
• Curic-Bawden Mirjana
• Janzen Thomas
• Birkelund Mimi
• Buchhorn Gäelle Lettier
• Soerensen Kim Ib
• Christensen Nanna
• Svane Claus
• Riis Soeren
• Pedersen Martin Bastian
• Odinot Jean-Marie
• Jimenez Luciana
• Lanciaux Pascal
• Hamm Duncan
• Siew Choon Ming

Classifications

• A23C2260/05

  Concentrated yoghurt products, e.g. labneh, yoghurt cheese, non-dried non-frozen solid or semi-solid yoghurt products other than spreads; Strained yoghurt; Removal of whey from yoghurt · CPC title

• A23C9/123

  using only microorganisms of the genus lactobacteriaceae; Yoghurt (A23C9/13 takes precedence) · CPC title

• A23C9/1206 Primary

  Lactose hydrolysing enzymes, e.g. lactase, beta-galactosidase · CPC title

• A23C9/1238 Primary

  using specific L. bulgaricus or S. thermophilus microorganisms; using entrapped or encapsulated yoghurt bacteria; Physical or chemical treatment of L. bulgaricus or S. thermophilus cultures; Fermentation only with L. bulgaricus or only with S. thermophilus · CPC title

• A23Y2220/15

  Human Necessities · mapped topic