Extrusion process for making infant formula with large lipid globules

Abstract

The present invention concerns a process for manufacturing an infant formula product comprising lipid globules having a volume-weighted mode diameter of at least 1.0 μm, wherein the process comprises: (a) subjecting an aqueous mixture having a protein component and a carbohydrate component to a heat treatment step; (b) mixing the aqueous mixture with a lipid component to obtain a oil-in-water emulsion having a total solids content in the range of 45-80 wt %; (d) conveying the homogenized emulsion into an extruder, independently adding digestible carbohydrates and optionally dietary fibres to the extruder and extruding the contents of the extruder to obtain an extruded material; (e) preparing an infant formula product from the extruded material, wherein step (e) involves a step wherein the extruded material is subjected to drying, wherein the drying may be selected from flash drying, vacuum drying, belt drying, microwave drying, IR drying and spray-drying, provided that the spray-drying uses an atomization system employing a two-fluid nozzle or a rotary atomization system, to obtain a spray-dried composition comprising lipid globules having a volume-weighted mode diameter of at least 1.0 μm. Alternatively, the process according to the invention does not employ a mixing step (b), but instead a lipid component is independently added during step (d). The invention further concerns Infant formula product obtainable by the process according to the invention and to a modular system suitable for performing the process according to the invention.

Claims

1. Process for manufacturing an infant formula product comprising lipid globules having a volume-weighted mode diameter of at least 1.0 μm, wherein the process comprises the following steps: (a) subjecting an aqueous mixture having a protein component and a carbohydrate component to a heat treatment step, (b) mixing the aqueous mixture with a lipid component, to obtain an oil-in-water emulsion having a total solids content in the range of 45-80 wt %; (d) conveying the emulsion into an extruder, independently adding digestible carbohydrates (e.g. lactose) and optionally dietary fibres to the extruder and extruding the contents of the extruder to obtain an extruded material; (e) preparing an infant formula product from the extruded material, wherein step (e) involves a step wherein the extruded material is subjected to drying, wherein the drying may be selected from flash drying, vacuum drying, belt drying, microwave drying, IR drying and spray-drying, provided that the spray-drying uses an atomization system employing a two-fluid nozzle or a rotary atomization system, to obtain a spray-dried composition comprising lipid globules having a volume-weighted mode diameter of at least 1.0 μm.

2. The process according to claim 1, wherein step (e) involves a spray-drying step, which is preferably performed at a pressure of at most 10 bar.

3. The process according to claim 1, wherein the protein component of the infant formula has a weight ratio of whey protein to casein in the range of 9/1 to 1/9.

4. The process according to claim 1, wherein the total solids content of the oil-in-water emulsion of step (b) is in the range of 45-73 wt %.

5. The process according to claim 1, wherein the digestible carbohydrates, such as lactose and/or maltodextrin, are added in step (d) as a dry powder and the dietary fibres are added as a dry powder or as a concentrated liquid.

6. The process according to claim 1, wherein the extrusion of step (d) is performed at a temperature below 75° C.

7. The process according to claim 1, wherein the heat treatment of step (a) is designed to obtain a microbial safe protein component and preferably is carried out by pasteurization, UHT, HTST or ESL, more preferably by pasteurization.

8. The process according to claim 1, wherein the aqueous mixture of step (a) has a total solids content in the range of 15-40 wt %.

9. The process according to claim 1, wherein the aqueous mixture subjected to step (b) has a total solids content in the range of 35-60 wt % prior to the mixing with the lipid component.

10. The process according to claim 1, wherein the total solids content of the aqueous mixture obtained in step (a) is increased, preferably by an evaporation step, prior to mixing with the lipid component.

11. The process according to claim 1, wherein skim milk and/or whey protein concentrate (WPC) are used as source of the protein component and carbohydrate component of the aqueous mixture subjected to step (a).

12. The process according to claim 1, wherein the carbohydrate component in step (a) comprises lactose, which lactose constitutes between 15 and 75 wt % of the total lactose contents of the infant formula product prepared in step (e).

13. The process according to claim 1, wherein the digestible carbohydrate that is added during step (d) comprises lactose and the amount of lactose added during step (d) lies between 0 and 80 wt % (on dry weight basis) of the total amount of lactose contained in the infant formula product obtained in step (e), preferably between 25 and 50 wt %.

14. The process according to claim 1, wherein the digestible carbohydrate that is added during step (d) comprises lactose and the amount of lactose that is added during step (d) lies between 0 and 40 wt % of the total dry weight of the infant formula product obtained in step (e), preferably between 0 and 30 wt %.

15. Infant formula product obtainable by the process according to claim 1.

16. The infant formula product according to claim 15, which is an infant formula, a follow-on formula, a toddler milk or a growing-up milk.

17.-18. (canceled)

19. Process for manufacturing an infant formula product comprising the following steps: (a) subjecting an aqueous mixture having a protein component and a carbohydrate component to a heat treatment step, (d) conveying the heat-treated aqueous mixture into an extruder, independently adding a lipid component, digestible carbohydrates (e.g. lactose) and optionally dietary fibres to the extruder and extruding the contents of the extruder to obtain an extruded material; (e) preparing an infant formula product from the extruded material.

20.-36. (canceled)

Description

FIGURES

[0219] The invention is illustrated by FIG. 1, depicting a preferred embodiment of the process according to the invention.

[0220] FIG. 1 depicts a preferred embodiment of the process according to the invention, wherein (a), (b), (d) and (e) represent steps (a), (b), (d) and (e) as defined herein. (1)=introduction of a source of protein and digestible carbohydrate; (2)=optional introduction of a second source of protein and digestible carbohydrate; (3)=introduction of a lipid component (4) introduction of a digestible carbohydrate component; (5)=optional introduction of a dietary fiber component; (6)=discharge of the infant formula product. In the process according to aspect 2 of the invention, module (b) is optional.

EXAMPLES

[0221] The following examples illustrate the invention.

Example 1

[0222] A process flow was generated for production of an infant formula intended for infants with an age of between 0 and 6 months. In a first step, demineralized whey (Demin Whey, flowrate 3166 kg/h), liquid whey protein concentrate 80 (WPC80, flowrate 430 kg/h), water (flowrate 677.2 kg/h) and the required amounts of micronutrients (i.e. vitamins and minerals) were compounded into an aqueous liquid with a total solids content (% TS) of 25 at a temperature of 35° C., and processed at a flowrate of 4419 kg/h.

[0223] The aqueous liquid was subsequently heat treated at 121.0° C. with a residence time of 2.89 seconds to achieve an F.sub.0 of 2.4. After cooling, the heated solution is subsequently fed into an evaporator for concentration purposes during which water was removed at a flowrate of 1943.5 kg/h. After evaporation, the aqueous solution has a % TS of 44.6 and is conveyed with a flowrate of 2475.5 at a temperature of 60° C. to the oil injector. Oils necessary to produce the infant formula are injected into the aqueous stream at a flowrate of 2337.32 kg/h to reach a % TS of 71.5. The solution is subsequently mixed at 60° C. using a flowrate of 4812 kg/h. The oil-in-water emulsion is conveyed to the extruder.

[0224] During extrusion, whey protein concentrate (WPC35, flowrate 388.8 kg/h), whey protein concentrate powder (WPC80, flowrate 91.2 kg/h), skim milk powder (SMP, flowrate 1349.3 kg/h), lactose (1417.4 kg/h) and GOS (Vivinal GOS; concentrated liquid at 75 wt %, flowrate 1685.9 kg/h) were added. GOS is added as the final ingredient during the extrusion process. Extrusion is performed at 63° C. at a flowrate of 9745.6 kg/h. The extrudate as obtained contained 80%TS and was ready for drying using known technologies, such as flash or vacuum belt drying, to end up with a nutritional composition with a % TS of 97.5 which was produced at a flowrate of 7996.4 kg/h. No dry blending of further ingredients is required. A powdered composition was obtained that was ready for packaging.

Example 2

[0225] A process flow was generated for production of an infant formula intended for infants with an age of between 6 and 12 months. In a first step, liquid whey protein concentrate 35 (WPC35, flowrate 1019.4 kg/h), water flowrate 3140.7 kg/h) and the required amounts of micronutrients (i.e. vitamins and minerals) were compounded into an aqueous liquid with a total solids content (% TS) of 25 ata temperature of 35° C., and processed ata flowrate of 4236.5 kg/h. Protein content of the aqueous liquid was 8.44 wt %.

[0226] The aqueous liquid was subsequently heat treated at 121.0° C. with a residence time of 2.89 seconds to achieve an F.sub.0 of 2.4. After cooling, the heated solution is subsequently fed into an evaporator for concentration purposes. After evaporation, during which water was removed with a flowrate of 1703.1 kg/h, the aqueous solution has a % TS of 41.8 and is conveyed with a flowrate of 2533.4 at a temperature of 60° C. to the oil injector. Oils necessary to produce the infant formula are injected with a flowrate of 2029.82 kg/h into the aqueous stream to reach a % TS of 67.69. The solution is mixed at 60° C. using a flowrate of 4563.2 kg/h. The oil-in-water emulsion is conveyed to the extruder.

[0227] During extrusion, skim milk powder (SMP, flowrate 1633.45 kg/h), lactose (2472.24 kg/h) and GOS (Vivinal GOS; concentrated liquid at 75 wt %, flowrate 1084.8 kg/h) were added. GOS is added as the final ingredient during the extrusion process. Extrusion is performed at 65° C. at a flowrate of 9753.68 kg/h. The extrudate as obtained contained 80%TS and was ready for drying using known technologies, such as flash or vacuum belt drying, to end up with a nutritional composition with a % TS of 97.5 which was produced at a flowrate of 8003.0 kg/h. No dry blending of further ingredients was required. A powdered composition was obtained that was ready for packaging.

Example 3

[0228] Data mentioned in example 1 and 2 were generated using the gPROMS gFormulatedProducts 1.2.2 simulation model from Process Systems Enterprise (PSE). Mass balance models used were steady state, meaning no accumulation in time is applied. Models were applied on a macro level without applying any discretization method.

[0229] For evaporation/concentration the mass balance of equation (1) was applied.

[00001]$\begin{array}{cc}0={\phi }_m^{in}-{\phi }_m^{out}-{\phi }_m^{evap}& \left(1\right)\end{array}$

It states that the amount of evaporated water or water otherwise removed

[00002]$\left(\frac{\mathrm{kg}}{s}\right)$

from a stream, plus the outlet from a stream should be equal to an inlet stream. From this perspective the outlet total solids

[00003]$\left(\frac{\mathrm{kg}}{\mathrm{kg}}\right)$

were calculated via equation (2):

[00004]$\begin{array}{cc}{x}_{\mathrm{solids}}^{out}=\frac{x_{\mathrm{solids}}^{in}{\phi }_m^{in}}{{\phi }_m^{out}}& \left(2\right)\end{array}$

This was applied under the assumption that extracted water, extracted via evaporation or any other technology, is pure water.

[0230] The same approach was used for mixing of different streams either within compounding (i.e. preparation of an aqueous mixture prior to heat treatment step a), fat injection (i.e. step b) or extrusion (step d). Equation (3) applies for the total mass balance:

[00005]$\begin{array}{cc}{\phi }_m^{out}=\underset{i=1}{\overset{N_{\mathrm{streams}}}{.Math.}}{\phi }_{m_i}^{in}& \left(3\right)\end{array}$

The solids outlet of any mixer and/or extruder was calculated by adapting equation (3) in case multiple inlet streams were applied:

[00006]$\begin{array}{cc}{x}_{\mathrm{solids}}^{out}=\frac{\underset{i=1}{\overset{N_{\mathrm{streams}}}{.Math.}}{x}_{\mathrm{solids},i}^{in}{\phi }_{m_i}^{in}}{{\phi }_m^{out}}& \left(4\right)\end{array}$

For the drying step, independent of the drying technology, equations 1 and 2 were applied to calculate the water evaporation capacity.

[0231] These equations were applied in a flowsheet construction. The information passed between models in a product flow are the mass flowrate and the composition (kg/kg).