Methods for making grill-type smoked food ingredients

Abstract

A method for making a liquid (e.g. water or oil)-based food ingredient, having grill flavour properties, comprises: combusting in the presence of oxygen, an intimate mixture of (i) 2-15 parts by weight smoke source and (ii) 1 part by weight flavour source, to generate smoke; and combining the smoke with a liquid carrier, yielding the food ingredient, wherein the flavour source comprises a lipid having an oleic acid content (whether free or esterified) of 20% or higher.

Claims

1. A method of making a food ingredient, comprising: providing a homogenous mixture of (i) smoke source and (ii) flavour source; combusting the homogenous mixture to generate smoke; and combining the smoke with a carrier, yielding the food ingredient, wherein the flavour source comprises a lipid.

2. The method of claim 1, wherein the smoke source is in finely divided, particulate form.

3. The method of claim 1, wherein the smoke source is in powdered form.

4. The method of claim 1, wherein the carrier is a liquid carrier.

5. The method of claim 1, wherein the carrier is an oil having a saturated fat content of 10% or above.

6. The method of claim 1, wherein the flavour source is a lipid that contains oleic acid.

7. The method of claim 6, wherein the lipid is selected from animal fats, and oils, wherein the animal fat is selected from pig fat, beef fat, mutton fat, bacon dripping, chicken fat, turkey fat, and mixtures thereof.

8. The method of claim 6, wherein the lipid is selected from olive oil, pecan oil, canola oil, peanut oil, macadamia oil, sunflower oil, grape seed oil, sea buckthorn oil, sesame oil, poppyseed oil, safflower oil, pumpkin seed oil, rice bran oil, almond oil, rapeseed oil, and mixtures thereof.

9. The method of claim 1 comprising combusting the mixture in the presence of oxygen.

10. The method of claim 1, wherein the smoke source comprises combustion material selected from: (1) wood chips, wood dust, wood shavings, wood briquettes, logs, smoke-free solid fuel, charcoal, and charcoal briquettes; and (2) mixtures of two or more of (1); and also comprises (3) filter material that selectively reduces the PAH content of the smoke, by selectively removing therefrom one or more PAHs that contain 4 or more benzene rings.

11. The method of claim 10, wherein the combustion material comprises: (1) 1-20 parts by weight of smoke-free fuel; and (2) 20-1 part by weight of the smoke generating fuel; and (3) 2-30% by weight of the total of (1)+(2) of filter material.

12. The method of claim 1 wherein the mixture comprises from 1:10 to 1:150 flavour source:smoke source by weight.

13. The method of claim 1 for making an oil-based food ingredient, comprising: combusting at a temperature of from 200 to 380 degrees C., in the presence of oxygen, a mixture of (i) 5-150 parts by weight smoke source and (ii) 1 part by weight flavour source, to generate smoke; and combining the smoke with an oil-based carrier, yielding the food ingredient, wherein the flavour source comprises a lipid having an oleic acid content (whether free or esterified) of 20% or higher.

14. The method of claim 13, wherein the smoke source comprises a substantially homogenous mixture of wood dust:charcoal dust at a ratio of 1-3:3-1 by weight and wherein the flavour source comprises sunflower oil or lard or tallow and the carrier comprises sunflower oil.

15. The method of claim 1, wherein: the homogenous mixture further comprises a zeolite; the carrier is a liquid carrier; and the lipid is an oil or a fat.

16. The method of claim 15, wherein the liquid carrier is an oil having a saturated fat content of 10% or above.

17. The method of claim 15, wherein the intimate homogenous mixture comprises: (1) 1-20 parts by weight smoke-free fuel; and (2) 20-1 part by weight of the smoke generating fuel; and (3) 2-30% by weight of the total of (1)+(2) zeolite.

18. The method of claim 15, wherein the mixture comprises from 1:10 to 1:150 oil or fat:smoke-generating source by weight.

19. A method of making an oil-based food ingredient, comprising: combusting at a temperature of from 200 to 380 degrees C., in the presence of oxygen, a mixture of (i) 5-150 parts by weight smoke-generating source and (ii) 1 part by weight oil or fat, to generate smoke; and combining the smoke with an oil-based carrier, yielding the food ingredient, wherein the oil or fat comprises a lipid having an oleic acid content (whether free or esterified) of 20% or higher.

20. The method of claim 19, wherein the smoke-generating source comprises a substantially homogenous mixture of wood dust:charcoal dust at a ratio of 1-3:3-1 by weight and the carrier comprises sunflower oil.

Description

(1) The invention is now described in specific examples with reference to the accompanying drawings in which:

(2) FIG. 1 shows a schematic diagram of apparatus for making flavoured oil; and

(3) FIG. 2 shows a schematic diagram of apparatus for making flavoured water.

EXAMPLES

Example 1—Preparation of Flavoured Oil

(4) A grill flavour was prepared by combustion of high oleic acid sunflower oil (smoke point—323° C., flash point—315° C., fire point—371° C.).

(5) Materials

(6) Charcoal dust (particle size up to approx. 1 mm)—4500 g

(7) Oak sawdust—4500 g

(8) Combustion oil (flavour source): High Oleic Sunflower Oil—180 g

(9) Carrier oil: High Oleic Sunflower Oil—2 L

(10) Apparatus

(11) Combustion apparatus, shown schematically in FIG. 1 was made up of a smoke furnace 2 into which air was pumped from fan 1. Smoke exiting the chamber passed via silicon tube 5 into mixing vessel 4 with continuous agitation by low-shear mixer 3.

(12) Method

(13) The 4500 g of charcoal and 4500 g of oak sawdust were weighed and mixed thoroughly to produce a homogenous blend. The blend was transferred into the smoke furnace. Two litres of high oleic sunflower oil were measured and transferred in the mixer vessel. The smoke furnace and the mixing vessel were connected using a silicon pipe. Afterwards, a small amount of hot ash was added to the wood-charcoal blend to start the smoking process. An air fan was connected to the furnace to control the air supply to the burning mix.

(14) The air supply was regulated using a probe targeted at the centre of the combustion mass so that the temperature of the burning mix was maintained at about 320-380 degrees and did not reach 400° C. A total of 180 g of the same high oleic sunflower oil was added in small amounts, at regular intervals to the wood-charcoal blend during burning. The wood blend was stirred at regular intervals to promote the production of smoke. This agitation also helped to keep the temperature in the desired range, and to avoid it reaching 400° C.

(15) The evolved smoke was continuously passed into carrier oil, with constant gentle mixing thereof, for 21 hours. The flavoured oil was tested and found to have a pleasant grill-type flavour. Testing for consumer reaction and comparison with known grill flavours is planned.

Example 2—Preparation of Flavoured Oil

(16) A grill flavour was prepared by combustion of high oleic acid sunflower oil (smoke point—323° C., flash point—315° C., fire point—371° C.).

(17) Materials

(18) Charcoal dust (particle size up to approx. 1 mm)—4500 g

(19) Oak sawdust—4500 g

(20) Combustion oil (flavour source): High Oleic Sunflower Oil—180 g

(21) Carrier oil: High Oleic Sunflower Oil—2 L

(22) Apparatus

(23) Combustion apparatus, shown schematically in FIG. 1 was made up of a smoke furnace 2 into which air was pumped from fan 1. Smoke exiting the chamber passed via silicon tube 5 into mixing vessel 4 with continuous agitation by low-shear mixer 3.

(24) Method

(25) The 4500 g of charcoal, 4500 g of oak sawdust and 180 g of combustion oil were weighed and mixed thoroughly to produce a homogenous blend. The blend was transferred into the smoke furnace. Two litres of high oleic sunflower oil were measured and transferred in the mixer vessel. The smoke furnace and the mixing vessel were connected using a silicon pipe. Afterwards, a small amount of hot ash was added to the wood-charcoal-oil blend to start the smoking process. An air fan was connected to the furnace to control the air supply to the burning mix.

(26) The air supply was regulated using a probe targeted at the centre of the combustion mass so that the temperature of the burning mix was maintained at about 320-380 degrees and did not reach 400° C. The combustion mass was stirred at regular intervals to promote the production of smoke. This agitation also helped to keep the temperature in the desired range, and to avoid it reaching 400° C.

(27) The evolved smoke was continuously passed into carrier oil, with constant gentle mixing thereof, for 21 hours. The flavoured oil was tested and found to have a pleasant grill-type flavour. Testing for consumer reaction and comparison with known grill flavours is planned.

Example 3—Preparation of Flavoured Oil

(28) A grill flavour was prepared by combustion of beef dripping.

(29) Materials

(30) Charcoal dust (particle size up to approx. 1 mm)—4500 g

(31) Oak sawdust—4500 g

(32) Combustion oil (flavour source): Beef dripping—180 g

(33) Carrier oil: High Oleic Sunflower Oil—2 L

(34) Apparatus and Method

(35) The procedure was repeated as for, and using the apparatus of, Examples 1 and 2 using the different combustion oil—in this case beef dripping.

(36) After the same period of continuous smoking, the carrier oil was tested and also found to have a pleasant grill-type flavour. Similarly detailed testing of this oil is planned.

Example 4—Preparation of Flavoured Water

(37) As shown schematically in FIG. 2, we used a water smoker 10 for preparation of flavoured water from oil and dripping (as per Examples 1 and 2 above).

(38) A compressor 12 was linked by pipe 14 to airtight smoke chamber (approx. 100 litres) 16, containing combustible material 20 (4500 g oak dust plus 4500 g charcoal dust plus 900 g clinoptilolite and then 450 g sunflower oil (run 1) or beef dripping (run 2)).

(39) The chamber smoke output was in turn linked to the stator portion of mixing head 28 of a YTRON® Y-ByPass mixer 24 via silicone rubber linking tube 22 and bypass pipe 26. The mixer is approximately 0.6 m tall with a power of 4.5 KW. The mixing head 28 is submerged during operation in water in a circular cross-section water pan (approx. 15 litres) 30.

(40) Calibration had been carried out based on smoking of water with various mixtures of wood dust and clinoptilolite, as a result of which the apparatus was set with the parameters: air was flowed into the smoke chamber 16 at approximately 127 litres per minute. Combustion material was placed in the bottom of the chamber as a single batch and electrical heat source 18 was switched on to ignite the dust, producing smoke. The air flow directed smoke to the mixing head via the linking tube and the bypass pipe. The mixer was turned on and also exerted a low level of suction, thus drawing smoke down the bypass pipe and into the water in the pan. The bypass pipe exit was of diameter approx. 25 mm and was located approximately 6 mm above the spinning impellers (set to approx. 60 Hz) of the mixer inside the mixing head, delivering the chamber output smoke right into the centre of the mixing; as the impellers span the smoke was intimately homogenised into tiny bubbles at the centre of the mixing head, with frothing seen at and around the head and at the water surface. Tiny bubbles were also seen dispersed throughout the water, swirling in the mixed water, having long residence times before rising to the surface. The few bubbles of smoke passing through the solution escaped into the atmosphere directly.

(41) Flavouring of the water was continued for 6 hours, to a pH of approx. 4 in the water and then the compressor and mixer switched off and the remaining dust left to extinguish by cutting off the air supply.

(42) Both runs produced water with recognisable grill flavour qualities and comparable with industry-standard “grill flavour”. In initial testing, some tasters described the ingredient as having a “savoury fatty flavour, with mild smokiness, better than grill flavour(s)”.

PARTS LIST FOR APPARATUS

(43) 1 fan 2 smoke furnace 3 mixer 4 mixing vessel 5 silicon tube 10 water flavouring apparatus 12 compressor 14 connection pipe 16 smoking chamber 18 heat source 20 combustible material 22 connection tube 24 homogeniser 26 bypass pipe 28 mixing head 30 water pan

Example 5—PAH Analysis

(44) A number of samples were smoked using the methods of the invention and, of these, four were sent away for PAH analysis at Eurofins Foods Testing UK Ltd.

(45) The samples analysed for PAH content were given internal references “S0035”, “S0048”, “S0094” and “S0207”. All four samples being smoked were high oleic sunflower oil, but each was smoked differently, as described below.

(46) S0035 (comparative example) was smoked from a burning composition comprising 15% oak wood, 1% cherry wood, 15% beech wood, 59% charcoal and 5% clinoptilolite, with unrefined sunflower oil (5%) being dripped onto the burning mixture.

(47) S0048 (comparative example) was smoked from a burning composition comprising 1% cherry wood, 15% mesquite wood, 15% beech wood, 59% charcoal and 5% clinoptilolite, with unrefined sunflower oil (5%) being dripped onto the burning mixture.

(48) S0094 was smoked from a burning composition comprising 3.5% oak wood, 1% cherry wood, 3.5% mesquite wood, 77% charcoal, 10% clinoptilolite, and 5% unrefined sunflower oil intimately mixed with the other components prior to burning.

(49) S0207 (comparative example) was smoked from a burning composition comprising 3.5% oak wood, 1% cherry wood, 3.5% mesquite wood, 77% charcoal and 10% clinoptilolite, with unrefined sunflower oil (5%) being dripped onto the burning mixture.

(50) The smoking conditions, e.g. smoking temperature, smoking duration and smoking apparatus, were controlled for samples S0094 and S0207 so that the only difference between those two samples was the method of applying the unrefined sunflower oil, i.e. intimately mixing prior to combustion (S0094) or dripping/spraying during combustion (S0207).

(51) The samples were then analysed for PAH content. Following European Commission Regulation 835/2011, the maximum acceptable level of PAHs in oils to be used as foodstuffs is 2.0 μg/kg for benzo(a)pyrene and 10 μg/kg for the sum of benzo(a)pyrene, benz(a)anthracene, benzo(b)fluoranthene and chrysene (sum of 4).

(52) Table 1 provides the results of the PAH analysis:—

(53) TABLE-US-00001 Sample Benzo(a)pyrene (μg/kg) Sum of 4 (μg/kg) S0035 4.8 39.5 S0048 4.3 31.1 S0094 1.1 9.9 S0207 2.9 27.4

(54) Levels of PAHs were significantly reduced by intimately mixing the flavour source, i.e. the unrefined sunflower oil, with the other components, i.e. the smoke source (in this case, various types of wood and charcoal) and the filter material (in this case, clinoptilolite), prior to combustion.

(55) It is seen that S0094, as per the invention, met both criteria of Regulation 835/2011 and the three comparative examples (S0035, S0048 and S0207) failed both criteria.

(56) The invention thus provides methods of preparing food ingredients, and the food ingredients thus produced.