PROCESS FOR PRODUCING EXPANDED BAKED FOOD PRODUCTS

Abstract

A process for producing expanded baked food products. comprises: preparing a food dough (4), placing the food dough (4) in an oven (1), solubilising under pressure at least one foaming agent in the food dough (4) placed in the oven (1), releasing the pressure so as to obtain an expanded food dough (4), baking the food dough (4) in the oven (1) to obtain an expanded baked food product and lastly removing the expanded baked food product from the oven (1).

Claims

1. A process for producing an expanded baked food product, comprising: i. placing a food dough (4) in an oven (1); ii. solubilising under pressure at least one foaming agent in the food dough (4) placed in said oven (1); iii. releasing the pressure so as to obtain an expanded food dough (4); iv. extracting the expanded baked food product from said oven (1); wherein the process further comprises: baking the food dough (4) in said oven (1) to obtain an expanded baked food product.

2. The process according to claim 1, wherein said baking the food dough (4) in the oven (1) is at least partially concurrent with step ii. and/or step iii.

3. The process according to claim 1, wherein steps ii. and iii. are repeated at least once.

4. The process according to claim 3, wherein steps ii. and iii. are repeated using different foaming agents and/or different working conditions in terms of time and/or pressure.

5. The process according to claim 1, wherein step ii. and/or step iii. is/are performed with a pressure profile of said at least one foaming agent variable in time and/or space.

6. The process according to claim 5, wherein the pressure profile comprises a pressurisation from a minimum pressure (P.sub.min) to a maximum pressure (P.sub.max) in a rising time (t.sub.1), an isobar phase at the maximum pressure (P.sub.max) for a dwell time (t.sub.2) and a de-pressurisation phase to the minimum pressure (P.sub.min) in a decreasing time (t.sub.3).

7. The process according to claim 6, wherein the minimum pressure (P.sub.min) is the atmospheric pressure (P.sub.atm) and the maximum pressure (P.sub.max) is comprised between 3 bar and 200 bar.

8. The process according to claim 6, wherein the rising time (t.sub.1) is comprised between 3 s and 600 s and/or wherein the dwell time (t.sub.2) is comprised between 10 s and 600 s and/or wherein the decreasing time (t.sub.3) is comprised between 10 s and 600 s.

9. The process according to claim 6, wherein the rising time (t.sub.1) is comprised between 3 s and 80 s and/or wherein the dwell time (t.sub.2) is comprised between 50 s and 200 s and/or wherein the decreasing time (t.sub.3) is comprised between 50 s and 100 s.

10. The process according to claim 1, wherein the foaming agent is a gas selected from the group comprising air, nitrogen, carbon dioxide, helium or a mixture of at least two of said gases.

11. The process according to claim 1, wherein the step of baking the food dough (4) in the oven (1) is performed at a baking temperature (T.sub.c) of the oven comprised between 100? C. and 300? C., optionally between 100?? C. and 200? C.

12. The process according to claim 1, wherein the step of baking the food dough (4) in the oven (1) is performed at a baking temperature (T.sub.c) of the oven comprised between 100? C. and 200? C.

13. The process according to claim 1, wherein the food dough (4) is prepared avoiding the use of any yeast or leavening agent.

14. The process according to claim 1, wherein placing the food dough (4) in the oven (1) comprises: positioning the food dough (4) on a support plane (6) of the oven (1).

15. The process according to claim 14, wherein solubilising under pressure said at least one foaming agent in the food dough (4) comprises: putting said at least one foaming agent under pressure in a solubilisation and baking chamber (3) of the oven (1) containing the food dough (4) until the foaming agent penetrates into the food dough (4) and saturates said food dough (4), so that, when in step iii. the pressure of the foaming agent is released, bubbles are formed and grow in the food dough (4) and said food dough (4) expands like foam.

16. An oven, comprising: a casing (2) delimiting a solubilisation and baking chamber (3) that can be sealed tightly; heating devices (5) operationally active in the solubilisation and baking chamber (3); pressurisation and de-pressurisation devices (8, 9, 10, 11, 12) operationally active in the solubilisation and baking chamber (3); at least one temperature sensor (13) and at least one pressure sensor (14) configured to detect at least one temperature and at least one pressure in the solubilisation and baking chamber (3); a control unit (15) operatively connected to the heating devices (5), to the pressurisation and de-pressurisation devices (8, 9, 10, 11, 12), to said at least one temperature sensor (13) and to said at least one pressure sensor (14); wherein the control unit (15) is configured and programmed/able to perform the process according to claim 1.

17. The process according to claim 6, wherein the minimum pressure (P.sub.min) is the atmospheric pressure (P.sub.atm) and the maximum pressure (P.sub.max) is from 5 bar to 20 bar.

Description

DESCRIPTION OF THE DRAWINGS

[0096] Such description will be outlined hereinafter with reference to the attached drawings, provided solely for by way of non-limiting example, wherein:

[0097] FIG. 1 schematically shows an oven configured to carry out the process of the present invention;

[0098] FIG. 2 is a flow chart of the process according to the present invention; and

[0099] FIG. 3 shows examples of tests conducted by applying the process according to the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0100] In FIG. 1, an oven configured to carry out the process for producing expanded baked food products (for example: bread, focaccia, pizza, baked pastry food products such as cakes, panettones, pandoros, colombas, etc.) according to the present invention, is indicated in its entirety with number 1.

[0101] The oven 1 comprises a casing 2 delimiting a solubilisation and baking chamber 3 that can be sealed tightly. The casing 2 comprises an opening so as to allow the introduction of the food dough 4 into the solubilisation and baking chamber 3 and a door associated with the opening to sealingly close said opening. The structure of the casing, the opening and the door have not been shown, given that they can be made in various ways, all within the reach of the person skilled in the art. The structure of the casing may be that of an autoclave given that it should guarantee the sealing of the solubilisation and baking chamber 3.

[0102] Heating devices 5 are operationally active in the solubilisation and baking chamber 3. In FIG. 1 such heating devices 5 are electric resistors arranged above and below a plane 6 for supporting the food dough 4, which may be possibly contained in a basket 7.

[0103] Furthermore, pressurisation and de-pressurisation devices are operationally active in the solubilisation and baking chamber 3.

[0104] The pressurisation and de-pressurisation devices comprise a source of pressurised gas 8 connected to an inlet 9 of the solubilisation and baking chamber 3 controlled through an inlet valve 10 associated with the inlet 9. The source of pressurised gas 8 may for example be a compressor configured for compressing atmospheric air or a reservoir containing a pressurised gas, such as for example the air or nitrogen, carbon dioxide, helium or a mixture of said gases, which is selected as a function of the food dough 4 to be baked, of the food product to be prepared and of the characteristics of said food product intended to be obtained.

[0105] In further variant embodiments, the foaming agent may be selected from hydrocarbons, chlorofluorocarbons, hydrochlorofluorocarbons.

[0106] The pressurisation and de-pressurisation devices further comprise an outlet 11 of the solubilisation and baking chamber 3 controlled through an outlet valve 12 associated with such outlet 11.

[0107] The oven 1 is further provided with a temperature sensor 13 and a pressure sensor 14 which are configured to respectively detect a temperature and a pressure within the solubilisation and baking chamber 3.

[0108] The oven 1 comprises a power supply unit, not shown, configured to guarantee the operation thereof and connected/which can be connected to the power mains.

[0109] A control unit 15 of the electric or electronic type is operatively connected to the electric resistors, to the source of pressurised gas 8, to the inlet valve 10, to the outlet valve 12, to the temperature sensor 13, to the pressure sensor 14, to the power supply unit and it is configured and/or programmed/able to manage the oven 1.

[0110] In particular, the control unit 15 is configured and programmed/able to carry out part of the process described below.

[0111] According to the process of the present invention, the food dough 4 is firstly prepared by combining and kneading the required ingredients, for example in a mixer, for example of the known type and not shown, that is before introducing it into the oven 1.

[0112] The food dough 4 is prepared without using any yeast or leavening agent. In particular, the entire process described herein is carried out avoiding the use of any yeast or leavening agent.

[0113] Once through with the preparation, the food dough 4 is placed in the basket 7 and positioned on the plane 6 for supporting the solubilisation and baking chamber 3 of the oven 1 previously brought to a baking temperature (T.sub.c) for example comprised between 100? C. and 300? C., optionally between 100? C. and 200? C.

[0114] In this non-limiting example, the baking starts right away and continues during the subsequent steps described below.

[0115] The door of the solubilisation and baking chamber 3 is closed and said solubilisation and baking chamber 3 is pressurised and subsequently de-pressurised through the source of pressurised gas 8, the inlet valve 10 and the outlet valve 12 and according to a pressure profile variable with time and previously set and managed by the control unit 15. As previously mentioned, the gas introduced into the solubilisation and baking chamber 3 is selected as a function of the food dough 4 to be baked, of the food product to be prepared and of the characteristics of said food product intended to be obtained.

[0116] The gas acts as a foaming agent given that, introduced under pressure into the oven 1 which already contains the food dough 4, penetrates into the food dough 4 and saturates said food dough 4 (i.e., the food dough 4 absorbs the gas) and, as a result, when the pressure of the gas is released (by opening the outlet valve 12 controlled by the control unit 15), bubbles are formed and grow within the food dough 4 and the latter expands like a sort of foam. In other words, the gas is solubilised in the food dough 4 under pressure so as to obtain an expanded food dough 4 once the pressure is released.

[0117] For example, the pressure profile comprises a pressurisation from a minimum pressure P.sub.min, for example from the atmospheric pressure P.sub.atm, to a maximum pressure P.sub.max. for example comprised between 3 bar and 200 bar, optionally between 5 bar and 20 bar, in a rising time t.sub.1, for example comprised between 3 s and 600 s, optionally between 3 s and 80 s, an isobar phase at the maximum pressure P.sub.max for a dwell time t.sub.2, for example comprised between 10 s and 600 s, optionally between 50 s and 200 s, and a de-pressurisation phase once again up to the minimum pressure P.sub.min in a decreasing time t.sub.3, for example comprised between 10 s and 600 s, optionally between 50 s and 100 s.

[0118] The pressure profile may also take values lower than the atmospheric pressure. Such pressure profile allows to generate an even expansion of the food dough. The conditions variable with time of the solubilisation step may also be calculated to generatein the food doughuneven profiles of the concentrations of gases which, upon the expansion, generate differentiated density and morphologies in the expanded food product.

[0119] During the pressurisation and de-pressurisation, the baking continues and it can also continue even after releasing the pressure. At the end of baking, the expanded baked food product is removed from the oven 1.

[0120] The aforementioned pressure profile and also a temperature profile may be defined as a function of the product to be prepared.

[0121] For example, the solubilisation under pressure (pressurisation and maintenance of the pressure, step ii.) and/or the release of the pressure (step iii.) may be fully or partly overlapped with the baking or the baking may be carried out at the end of step iii. (releasing the pressure).

[0122] The solubilisation and release cycle (steps ii. and iii.) may also be repeated several times during the process, with the same gas or also changing the gas used and/or with the same operating conditions or with different operating conditions in terms of pressure and/or time.

[0123] In an embodiment of the present invention, the oven 1 may be provided with bulkheads arranged/which can be arranged in the solubilisation and baking chamber 3 so as to partition said solubilisation and baking chamber 3 into partitions such to delimit areas of the food dough 4 subjected to different pressure values and/or on which different gases act. To this end, the oven 1 is provided with several inlets connected to respective sources of gas and with several outlets. Each inlet/outlet pair is placed in fluid communication with one of the aforementioned partitions. Therefore, the pressure takes values which vary, besides with time, also in the space as a function of the portion of the food dough.

[0124] Examples of tests conducted to verify the process according to the invention are shown below.

EXAMPLE 1PRIOR ART FOR COMPARISON

[0125] A food dough for pizzas was prepared in a mixer (5L, HAUSWIRT? Planetary Mixer) using 100 g of flour 0(Nuvola, CAPUTO?), 2.5 g of sea salt (GEMMA DI MARE Iodised Sea Salt) and 60 ml of water and 0.15 g of yeast (LIEVITAL Fresh Brewer's Yeast), following the recommendations laid down in the European Regulation No 97/2010 dated 4 Feb. 2010 (Pizza Napoletana as a Traditional Speciality Guaranteed). The food dough was used after 4 hours of leavening. A mini-batch system capable of reaching high pressure values and high temperatures, described in the work by D. Tammaro, V. Contaldi, M G Pastore Carbone, E. Di Maio, S. lannace, A novel lab-scale batch foaming equipment: The mini-batch, Journal of Cellular Plastics, 2016, was used as reactor (oven). An almost spherical sample with an approximately 10 mm diameter was introduced into the reactor at a temperature of 146?? C. and maintained for 240 s at atmospheric pressure, after which the reactor was opened and the foam (expanded food product) was removed for characterisation.

EXAMPLE 2INVENTION

[0126] A food dough for pizzas was prepared in a mixer (5L, HAUSWIRT? Planetary Mixer) using 100 g of flour 0 (Nuvola, CAPUTO?), 2.5 g of sea salt (GEMMA DI MARE lodised Sea Salt) and 60 ml of water following the recommendations laid down in the European Regulation No 97/2010 dated 4 Feb. 2010 (Pizza Napoletana as Traditional Speciality Guaranteed), avoiding the use of any type of yeast or leavening agent. The same reactor described in example 1 was used. After introducing an almost spherical sample with an approximately 10 mm diameter into the reactor (oven) previously brought to a temperature of 146? C., a pressure history using carbon dioxide was imposed using a control system provided with a pressure reader and actuated valves. In particular, the pressure history envisages a step of pressurising from atmospheric pressure to 15 bar in a rising time (t.sub.1) of 5 s, an isobar phase for a dwell time (t.sub.2) of 150 s and a de-pressurisation phase down to atmospheric pressure in a decreasing time (t.sub.3) of 90 s. At the end of the pressure program, the reactor was opened and the foam (expanded food product) was removed for characterisation.

[0127] EXAMPLE 3INVENTION

[0128] This example is identical to example 2 except for the fact that helium was used instead of carbon dioxide.

[0129] FIG. 3 shows a comparison of three examples shown above, in which lines 1, 2 and 3 show samples of the doughs according to examples 1, 2 and 3 while columns A, B and C respectively show: [0130] A initial condition of the dough samples seen through a sapphire window of the reactor/oven; [0131] B samples at the end of the process seen through the aforementioned window; and [0132] C internal morphology of the produced samples

[0133] The final density of the samples produced in the two examples of the invention (example 2 and 3) are similar (about 0.9 g/cm.sup.3) to the case of the comparison example (example 1). Also the analysis of the morphology shows comparable results, with porosity with diameters of about 300 ?m for the dough with yeast (example 1) and about 500 ?m for the samples obtained through physical foaming with carbon dioxide (example 2) and helium (example 3). Lastly, the helium (example 3) also allows to observe the formation of the typical crust not observed with carbon dioxide.

EXAMPLE 4PRIOR ART FOR COMPARISON

[0134] A food dough for cakes was prepared by mixing-with a hand whip-40 g of flour 0 (Nuvola, CAPUTO?), 40 g of sugar, 1 egg and 2 g of pastry yeast. The same reactor/oven described in example 1 was used. A sample of about 1 g of the liquid dough was poured into an aluminium container and placed in the reactor at a temperature of 120? C. and maintained for 360 s at atmospheric pressure, after which the reactor was opened and the foam (expanded food product) was removed for characterisation.

EXAMPLE 5-INVENTION

[0135] A food dough for cakes was prepared by mixing-with a hand whip-40 g of flour 0 (Nuvola, CAPUTO?), 40 g of sugar and 1 egg. The same reactor/oven described in example 1 was used. A sample of about 1 g of liquid dough was poured into an aluminium container and placed in the reactor at a temperature of 120? C. After closing the reactor, a pressure history was imposed using compressed air, through a control system provided with pressure reader and actuated valves. In particular, the pressure history envisages a step of pressurising from atmospheric pressure to 6 bar in a rising time (t.sub.1) of 60 s, an isobar phase to 6bar for a dwell stationary (t.sub.2) of 60 s and a de-pressurisation phase down to atmospheric pressure in a decreasing time (t.sub.3) of 60 s. At the end of the pressure program, the reactor is opened and the foam removed for characterisation.

[0136] In the comparison between the results of the experiment described in examples 4 and 5, the achievement of comparable densities is observed, in the order of 0.7-0.8 g/cm.sup.3 and comparable morphologies, with bubbles with diameter in the range of 0.1-0.5 mm.