System for the production of multi-strained yogurt

• US 10,638,770 B2
• Filed: 07/17/2014
• Issued: 05/05/2020
• Est. Priority Date: 07/18/2013
• Status: Active Grant

• Current Assignee: Delta S.A. Industrial And Commercial Company Of Food Products
• Original Assignee: Delta S.A. Industrial And Commercial Company Of Food Products
• Inventors: Anastasiadis, Achilleas, Koumanoudis, Nicolaos, Pitsinis, Nicolaos, Hatzigeorgiou, Artemis
• Primary Examiner(s): Wong, Leslie A
• Application Number:
  US14/905,897
• Publication Number:
  US 20160150800A1
• Time in Patent Office: 2,119 Days
• Field of Search: 426478, 426490, 426491, 426580, 426583, 99485, 99495
• CPC Class Codes: A23C 2260/05 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 Class Codes: A23C 9/122 Apparatus for preparing or treating fermented milk products
• CPC Class Codes: A23C 9/123 using only microorganisms of the genus lactobacteriaceae; Yoghurt A23C9/13 takes precedence

Abstract

The invention describes a system of industrial production of strained yogurt which enables the natural straining by means of separation means, with the optimal use of the raw material, with the least possible stressing of the raw material and with the minimum possible loss of useful ingredients in the whey which is removed after straining and with the optimal stability of the characteristics of the final product, in each production batch. The invention describes the critical conditions of processes upstream of (namely before) the straining process, such as the physiochemical features of the raw milk, conditions of pasteurization and homogenization, conditions of incubation etc and the stacks of suitably selected and positioned membranes that are used for the straining, so that the final strained yogurt has the desired physiochemical features (proteins, fat, total solids) upon its exit from the straining rig. During the straining process, the yogurt is consecutively strained at least twice and the process is complemented by the stages downstream of (namely after) the straining, such as the conditions of cooling, storage before packaging, packaging conditions etc., which also are critical factors in order to realize the final outcome.

Claims

1. A system for the production of strained yoghurt on an industrial scale, which comprises:

a first pump which is fed with incubated yoghurt with a fat content dependent on a predetermined fat type of strained yoghurt,

second and third pumps which transfer the yoghurt in order for it to be strained,

the yoghurt is introduced in a first stage of straining (A) through the second pump, the first stage of straining includes at least one first filter that is made of at least one straining membrane and a whey collection tube,

the whey is collected in the whey collection tube, after the first stage of straining,

after the first stage of straining (A), the strained yoghurt goes through a second stage of straining (B) by means of the third pump, the second stage of straining includes at least one second filter that is made of at least one straining membrane and a whey collection tube, and

wherein;

the straining process taking place at least twice,

each of the at least one straining membranes are wound spirally around the respective whey collection tube, in such a way so that the yoghurt that is inserted is pressurized by means of pressure of the second and third pumps and the whey enters through the at least one straining membranes in an adjacent whey collection compartment, the respective compartment leads the whey to the respective collection tube,

after the first stage of straining, the yoghurt is led by means of the second pump, to the second stage of straining, where is repeated the same process of straining and removal of the whey collected wherein the at least one membranes have semi-permeable walls having pores which allow substances of molecular weight up to 25.000 Da to exit to the whey collection compartment and the whey collection compartment at the center of the spiral wound communicates with the whey collection tube, by holes of the whey collection tube.

2. The system according to claim 1, wherein:

the multiple straining comprises eight stages (A, B, C, D, E, F, G, H), one after the other, and

from the second stage of straining (B) onwards and during the next stages of straining (C, D, E, F, G, H) the features and conditions of the second stage of straining (B) are repeated.

3. The system according to claim 1 wherein each of the straining stages comprises at least three straining membranes which function simultaneously and in parallel.

4. The system according to claim 1 wherein during the first stage of straining (A) as compared to the second stage of straining (B) and to every subsequent stage of straining (C, D, E, F, G, H)

the at least one straining membranes are wrapped in a first spiral in the first stage of straining (A), a second spiral in the second stage of straining (B) a subsequent spiral in the every subsequent stage of straining (C, D, E, F, G, H), the first spiral has a first distance between each wrapping of the first spiral, the second spiral has a second distance between each wrapping of the second spiral, the subsequent spirals have a subsequent distance between each wrapping of the subsequent spirals, the first distance is narrower than the second distance and each of the subsequent distances and

the straining membranes are divided by first layers in the first stage of straining (A), second layers in the second stage of straining (B) and subsequent layers in the every subsequent stage of straining (C, D, E, F, G, H), the first layers are thinner than the second layers and each of the subsequent layers,

wherein a first separation grid during the first stage of straining (A) is formed of the straining members of the first stage of straining (A), a second separation grid during the second stage of straining (A) is formed of the straining members of the second stage of straining (B), a subsequent grid during the every subsequent stage of straining (C, D, E, F, G, H) is formed of the straining members of the every subsequent stage of straining (C, D, E, F, G, H) and the first separation grid is thicker than the second separation grid and each of the subsequent e subsequent separation grids.

5. The system according to claim 1 wherein the third pump that is used from the second stage of straining (B) and at each of the subsequent stages (C, D, E, F, G, H) always applies more pressure in comparison to each one used in the previous stage.

6. The system according to claim 1 wherein the predetermined fat content of the final product is 2%, the concentration ratio of the yoghurt feed is 3 to 2 and when the predetermined fat content of the final product is 10%, the concentration ratio of the yoghurt feed is 2 to 3.

11. The system according to claim 1 wherein the incubated yoghurt introduced in the first stage of straining (A) comprises a raw material of treated as follows:

milk is pasteurized at a temperature between 90 and 97 C, for a time period ranging from 1 to 7 min,

the homogenization of the milk as a raw material has taken place at a temperature between 60 and 80 C, under pressure conditions of 50 to 350 bar and

the incubation has taken place at a temperature between 37 and 45 C,

when the incubation ceases, the yoghurt has a pH ranging from 4.3 to 4.7,

before the yoghurt reaches the at least one straining membrane, it is heated at a temperature between 50 and 60 C for a time period ranging from 1 to 3 min.

7. A method of producing strained yoghurt on an industrial range comprising:

feeding a first pump with incubated yoghurt which contains an amount of fat that is a function of the desired final fat content of the strained yoghurt,

transferring with a second pump a portion of the yoghurt to a first stage of straining (A),

yoghurt which has been submitted to a primary straining, and whey are produced during the first stage of straining (A),

collecting the whey,

feeding the strained yoghurt after having been submitted to the first stage of straining to a second stage of straining (B) by means of a third pump,

wherein;

the straining process is a multiple taking place at least twice,

every straining stage comprises at least one filter made of at least one straining membrane and a whey collection tube,

the at least one straining membrane is wound in spiral around the whey collection tube in such a way so that the yoghurt inserted by means of the pressure of the second pump is pressurized and its whey enters through the at least one straining membrane in an adjacent whey collection compartment layer which compartment leads the whey to the respective collection tube,

after the first stage of straining (A), the strained yoghurt is lead into the second stage of straining stage by the third pump, where is repeated the same process of straining and removal of the whey collected.

8. The method according to claim 7, wherein the multiple straining process involves eight stages (A, B, C, D, E, F, G, H), the straining takes place eight consecutive times, and wherein the characteristics and conditions of the second stage of straining are repeated from the third stage and to every consecutive stage.

9. The method according to claim 7 wherein each of the straining stages involves at least three straining membranes, which function simultaneously and in parallel,

during the first stage of straining (A) in comparison to the stages from the second stage of straining (B) onwards and to each subsequent stage of straining (C, D, E, F, G, H) the straining membranes are wrapped in a first spiral in the first stage of straining (A), a second spiral in the second stage of straining (B) a subsequent spiral in the every subsequent stage of straining (C, D, E, F, G, H), the first spiral has a first distance between each wrapping of the first spiral, the second spiral has a second distance between each wrapping of the second spiral, the subsequent spirals have a subsequent distance between each wrapping of the subsequent spirals, the first distance is narrower than the second distance and each of the subsequent distances, the straining members are divided by first layers in the first stage of straining (A), second layers in the second stage of straining (B) and subsequent layers in the every subsequent stage of straining (C, D, E, F, G, H), the first layers are thinner than the second layers and each of the subsequent layers,

during the first stage of straining (A) a first separation grid is formed of the straining members of the first stage of straining (A), a second separation grid during the second stage of straining (A) is formed of the straining members of the second stage of straining (B), a subsequent grid during the every subsequent stage of straining (C, D, E, F, G, H) is formed of the straining members of the every subsequent stage of straining (C, D, E, F, G, H) and the first separation grid is thicker than the second separation grid and each of the subsequent e subsequent separation grids,

the third pump of the second stage of straining (B) and of each of the subsequent stages (C, D, E, F, G, H) always applies more pressure in comparison to the previous pump of the previous stage.

10. The method according to claim 7 wherein when the predetermined content of fat of the final product is 2%, the yoghurt feed concentration ratio is 3 to 2 and in the case that the predetermined content of fat of the final product is 10%, the yoghurt feed concentration ratio is 2 to 3.