TECHNICAL FIELD OF THE INVENTION

The present invention relates to filled farinaceous bakery products, notably filled farinaceous bakery products that are usually produced by means of frying, such as filled doughnuts. The present invention provides an improved process for the preparation of such filled bakery products.

BACKGROUND OF THE INVENTION

If the production of filled bakery products comprises frying, the filling is usually introduced after frying, e.g. by injecting the filling into the fried product. This is because the filling may be 'fried out' of the product during frying and because undesirable losses of filling material into the frying medium are hard to avoid.

US 2005/0186316 describes a process for preparing fried bakery products, comprising the steps of:

• preparing a dough;

• subjecting thus obtained dough to preliminary fermenting and to dividing and molding, and

• fermenting the dough to obtain fermented molded products;

· partial-baking the fermented molded products to obtain partial-baked products;

• frying the partial-baked products to obtain fried bakery products.

Examples 11, 12 and 14 of the US patent application describe the preparation of bean jam doughnuts in which the filling is introduced into the fermented molded products before partial-baking and frying.

WO 2011/025370 describes a method of preparing a ready-to-eat farinaceous food product, said method comprising the successive steps of: • preparing a farinaceous dough by mixing flour, water and optionally one or more other bakery ingredients;

• dividing the dough into one or more dough portions;

• shaping the one or more dough portions into one or more shaped dough pieces; d)

contacting 30-70% of the total surface area of the one or more shaped dough pieces with hot oil during a period of at least 10 seconds to produce one or more partially fried dough pieces comprising a fried surface area and a non- fried surface area; and

• baking said one or more partially fried dough pieces to produce one or more baked dough pieces;

wherein a layer of edible material is applied to 40-70% of the surface area of the shaped dough pieces, the partially fried dough pieces or the baked dough pieces and wherein the surface area of the final ready-to-eat product that is not covered by the layer of edible material is fried surface area. US 4, 171,380 describes a method for the manufacture of edible filled products comprising:

• forming uncooked cereal dough into a sheet of predetermined dimensions,

• applying a layer of backing material on one side of the dough sheet, leaving perimeter margins of the dough sheet extending beyond the perimeter of the backing layer, the backing layer being of material capable of serving as a thermal barrier,

· depositing a mass of filling material on the backing layer,

• enclosing the filling within the dough sheets with the backing layer interposed between the filling and the layer of dough, and with margins of the dough layer overlapping, and

• pressing the overlapping margins directly together to form seals for the envelope, the layer of backing material being applied to the dough sheet in such a manner that its perimeter does not extend between the overlapping margins.

The patent teaches to subject the filled product to deep fat frying. The US patent describes an embodiment in which the filling is a frozen dessert, and in which the product is cooked by immersion in hot oil, thereafter chilled to freeze the same, stored in frozen condition, and thereafter surface warmed before eating.

WO 2000/076321 describes a method of forming a filled dough product by extruding a mixture comprising flour, water and chemical leavener and coextruding a filling. Leavening of the dough product is achieved by the extrusion. The extruded product may be cooked by frying, boiling, baking or microwave cooking. The Examples of the patent application describe filled dough products that have been fried.

The title of US 7,282,231 suggests that this patent relates to doughnut like dumplings covered with sesame seeds. However, sesame seeds are nowhere mentioned in the Examples and also no specific embodiment of such sesame seed covered products are provided. Examples 2 and 4 describe the preparation of a doughnut that contains a filling. The filling is introduced before frying. US 2010/0297301 describes a method of producing a filled food product, comprising at least the steps of:

• heat-processing one or more filling ingredients,

• mixing the heat-processed filling ingredients with water-soluble cellulose ether which is gelable during heating, to thereby obtain a filling; and

· wrapping the filling with a dough skin, followed by subjecting to any one of heating, baking, and frying.

EP-A 1 832 172 describes a method of preparing a ready-to-eat foodstuff, said method comprising the steps of:

· applying a fat-based coating to the exterior of an uncooked or incompletely cooked

foodstuff; and

• contacting the fat coated foodstuff with superheated steam having a temperature of 120- 300 °C for a period of 0.3-15 minutes, preferably of 1 -10 minutes to obtain the ready-to- eat foodstuff.

The uncooked or incompletely cooked foodstuff contains at least 40 wt.% of a flour-based dough or batter and optionally up to 80 wt.% of a filling based on the weight of the uncooked or incompletely cooked foodstuff. Example 6 describes the preparation of a ring doughnuts by dipping proofed doughnuts for 10 seconds in hot oil having a temperature of 180°C, followed by contacting with superheated steam.

US 3,479, 188 describes a process for cooking bakery products, such as doughnuts, by first subjecting it to microwave energy for a sufficient period of time to allow it to expand and to set a crumb structure of the dough without the presence of a crust followed by subjecting the bakery product to deep fat frying. In column 5, lines 20-21 it is observed that fruits such as raisins or blueberries and the like can be added if desired.

SUMMARY OF THE INVENTION

The inventors have developed a process for the preparation of filled farinaceous bakery products that employs frying of a filled farinaceous product and that offers the advantage that loss of filling material during frying is minimized. More particularly, the present invention provides a process of preparing a ready-to-eat bakery product comprising:

• preparing filled pieces of dough or batter by homogeneously dispersing pieces of a non- farinaceous filling material through dough or batter;

• contacting the filled pieces with hot oil having a temperature of 150-350°C for 1-80

seconds to partially cook the filled pieces; and

· baking said one or more partially cooked filled pieces to produce the ready-to-eat bakery product.

This process offers the advantage that the pieces of the filling material that end up embedded in the surface of the filled pieces are not 'fried out' of the filled pieces.

The invention further relates to a ready-to-eat bakery product that is obtained by the aforementioned process.

DETAILED DESCRIPTION OF THE INVENTION

One aspect of the present invention relates to a process of preparing a ready-to-eat bakery product comprising:

• preparing filled pieces of dough or batter by homogeneously dispersing pieces of a non- farinaceous filling material through dough or batter, said pieces of non-farinaceous filling material having a piece volume of 1 mm ³ to 4 cm ³ , said filled pieces containing 50-95 wt.% of a matrix of dough or batter and 5-50 wt.% of the pieces of filling material, wherein at least 30 wt.% of said pieces of filled material is completely enveloped by the matrix of dough or batter and at least 5 wt.% of these pieces of filling material is not fully enveloped by the matrix of dough or batter;

• contacting the filled pieces with hot oil having a temperature of 150-350°C for 1-80

seconds to partially cook the filled pieces; and

· baking said one or more partially cooked filled pieces to produce a fully cooked ready-to- eat bakery product.

The terminology "non-farinaceous filling material" as used herein refers to a filling material that is neither a dough nor a batter.

The "combining dough or batter with a non-farinaceous filling material" in the present process may be achieved by first preparing the dough or batter and then combining it with the filling material. Alternatively, this is achieved by combining one or more of the dough or batter ingredients with the filling material and further processing the combination of filling material and ingredients to produce the filled pieces of dough or batter.

Throughout this document the terms "oil" and "fat" are used interchangeably and encompass triglycerides, diglycerides, monoglycerides, phospholipids and combinations thereof. The term "baking" as used herein refers to the prolonged cooking of the partially cooked filled pieces by dry heat, as opposed to e.g. boiling or frying. It should be understood that besides conventional oven baking the term "baking" encompasses the contacting of the partially cooked filled pieces with superheated steam as well as the exposure of said dough pieces to hot air impingement or infrared radiation.

The non-farinaceous filling material is suitably selected from chocolate, fruit, nuts, fruit preparations, fruit jam, jelly, custard, cream, meat products, cheese, ragu, cereals and combinations thereof. Here the term "cereal" refers to non-milled cereal grain. The present process advantageously employs a dough or a batter that contains a leavening agent. Preferably, the dough or batter contains 0.5-20%, more preferably 1-15% by weight of flour of a leavening agent selected from yeast, chemical leavener and combinations thereof. The present process is particularly suitable for preparing ready-to-eat products that have been leavened with the help of yeast and/or a chemical leavening agent prior to the contacting with the hot oil. Advantageously the matrix of dough or batter of the filled pieces has a specific volume of at least 1.2 ml/g, more preferably of at least 2.0 ml/g before the filled pieces are contacted with the hot oil.

According to a particularly preferred embodiment, the filled pieces are prepared by combining a dough with the filling material. Typically, said dough contains 40-80% water by weight of flour and 10-65%, preferably 20-60%) of other edible ingredients by weight of flour.

Advantageously, the dough contains active yeast and the filled pieces are proofed before being contacted with the hot oil.

In accordance with one preferred embodiment of the present process, the pieces of filling material have a piece volume of 0.01-1 cm ³ .

Preferably, the pieces of filling are selected from dry fruit, nuts, chocolate, cereals and combinations thereof.

The benefits of the present process are particularly appreciated in case a significant amount of the filling material is located at the surface of the filled pieces. Accordingly, preferably at least 10wt.%, more preferably at least 20 wt.% and more preferably at least 30 wt.% of the pieces of filling material contained in the filled pieces are not fully enveloped by dough or batter. In the present process the filled pieces are preferably contacted with the hot oil for 2-60 seconds, even more preferably for 4-40 seconds and most preferably for 6-30 seconds. The hot oil that is employed to partially cook the filled pieces preferably has a temperature of 160- 250°C, most preferably of 170-210°C. The contacting with hot oil can be achieved in many different ways, e.g. by partly or completely immersing the filled pieces in hot oil, by spraying the shaped dough pieces with hot oil or by placing the shaped dough pieces onto a hot layer of oil (shallow frying).

Preferably, the contacting with the hot oil is achieved by partly or completely immersing the filled pieces in hot oil. The filled pieces typically have a weight of 2-200 g before they are contacted with the hot oil. Preferably, said filled pieces have a weight of 4-150 g, most preferably of 10-130g before they are contacted with the hot oil.

Typically, at least 50 wt.% of the starch contained in the partially cooked filled pieces is non- gelatinized at the beginning of the baking. Most preferably, at least 60% of said starch is non- gelatinized at the beginning of the baking. Best results are obtained with the present process if the partially cooked filled pieces are baked quickly after the frying. Preferably, the baking of the one or more partially cooked filled pieces commences within 5 minutes, more preferably within 3 minutes and most preferably within 1 minutes after the contacting with the hot oil has ended. The present process can employ a variety of baking techniques to fully cook the partially cooked filled pieces. In accordance with a preferred embodiment of the present invention the partially cooked filled pieces are baked by subjecting the pieces to one or more of the following heat treatments:

• holding said dough pieces in an oven having an oven temperature of at least 150°C for at least 1 minute;

• contacting said dough pieces to superheated steam,

• exposing said dough pieces to hot air impingement;

• exposing said dough pieces to infrared radiation having a wavelength in the range of 0.7- 10 μιη.

The terms "superheated steam" as used herein refers to steam having a (static) pressure that is below the saturated vapour pressure of said steam. The saturated vapour pressure of steam varies with temperature. The higher the temperature, the higher the saturated vapour pressure. Because the pressure of the superheated steam employed in the present process is lower than the saturated vapour pressure, the steam is capable of drying, that is, vaporising the water out of the partially cooked filled pieces with which the superheated steam flow is contacted. The term "infrared radiation" as used herein refers to electromagnetic radiation having a wavelength of 0.7 μιη to 1 mm. Whenever reference is made herein to infrared radiation having a wavelength within a certain range, what is meant is that more than 50%, preferably more than 80% of the energy content of the infrared radiation stems from infrared radiation having a wavelength within said range.

The term "air" as used in relation to impingement with hot air should not be construed narrowly, as impingement with gases or gas mixtures other than air may produce similar results. Preferably, the hot air employed in the present process contains at least 50 wt.% of air. Most preferably, the hot air employed consists of air.

If the partially cooked filled pieces are baked in an oven, advantageously an oven temperature in the range of 150-350°C, most preferably in the range of 180-320°C is used. Typically, the partially cooked filled pieces will be held in an oven at the indicated oven temperature for a period of 2-20 minutes, most preferably for 4-10 minutes.

The temperature of the superheated steam employed in the present process can vary within a broad range. In order to obtain a ready-to-eat foodstuff with a slightly browned skin and a fully cooked interior an adequate combination of steam temperature and contact time should be chosen. Generally speaking, the higher the steam temperature, the shorter the contact time. Preferably, the superheated steam employed in the present process has a temperature in the range of 130-280°C, most preferably of 150-250°C. The partially cooked filled pieces are suitably contacted with the superheated steam for at least 30 seconds, more preferably for 75- 150 seconds.

The partially cooked filled pieces are advantageously contacted with superheated steam having a pressure that is substantially below its saturated vapour pressure.

According to a particularly preferred embodiment, the superheated steam has a pressure of 0.15 to 0.95 times, preferably of 0.3 to 0.8 times the water vapour pressure of the superheated steam.

The contacting of the partially cooked filled pieces with the superheated steam is suitably achieved by passing a steady flow of superheated steam over the partially cooked pieces. In order to ensure that the cooking process will proceed at an adequate rate it is preferred to pass superheated steam over the dough pieces at a flow rate of at least 1 m/s, preferably of at least 3 m/s. Usually, the flow rate does not exceed 50 m/s, preferably it does not exceed 30 m/s. Direct contact between the superheated steam and the partially cooked filled pieces is required to achieve the desired product characteristics. Direct contact is particularly relevant for achieving adequate surface browning and moisture reduction. Hence, if the dough pieces are contacted with the superheated steam while being placed on a tray or being held in a basket, it is essential that superheated steam can penetrate through such a tray or basket to reach the surface of the dough pieces. Typically, in the present process at least 80%, preferably at least 90% of the surface of the partially cooked filled pieces is exposed directly to the superheated steam.

In the present process the infrared radiation can suitably be provided by any type of infrared heater that is capable of producing infrared radiation with the right wavelength. The latter wavelength is dependent on the temperature of the emitting body. Most commercially available infrared heaters employ a flame or an electrically heated filament as the emitting body. The present process advantageously employs a infrared heater that contains an electrically heated filament as the emitting body. This filament may be protected by a heat- resistant quartz glass tube. Furthermore, said quartz tube may be filled with inert gas to prevent filament degradation. In the present process the infrared radiation is advantageously provided by infrared tube heaters.

The present process preferably employs infrared radiation having a very high energy content. Consequently, in a particularly preferred embodiment, the infrared radiation employed has a wavelength of 0.7-5.0 μπι.

Preferably, in the present process the infrared radiation to which the partially cooked filled pieces are exposed has a high power density. Advantageously, the partially cooked filled pieces are exposed to a heat flux of at least 2 kW/m ² , more preferably of at least 5 kW/m ² and most preferably of 8-80 kW/m ² for at least 20 seconds.

Advantageously, the total time period during which the partially cooked filled pieces are exposed to the aforementioned heat flux is at least 40 seconds, more preferably at least 60 seconds and most preferably at least 90 seconds. Typically, the time period during which the partially cooked pieces are exposed to the earlier mentioned heat flux does not exceed 700 seconds. Preferably, said time period does not exceed 500 seconds.

Also the hot air impingement employed in the present process advantageously is used to achieve a very intense heat transfer into the partially cooked filled pieces.

Accordingly, the filled pieces are preferably exposed to impingement with hot air having a temperature of 180-340°C, more preferably of 200-320°C. The effectiveness of the impingement with hot air depends on the temperature of the hot air, but also on the flow rate of said hot air. Advantageously, the impingement with hot air comprises impinging the filled pieces with hot air having a velocity of at least 1 m/s, preferably of 5-20 m/s.

Typically, the dough employed in the present process contains 40-60% of water by weight of flour and 0-50% of other bakery ingredients by weight of flour.

Another aspect of the invention relates to a ready-to-eat food product that is obtained by a process as described herein.

The ready-to-eat farinaceous product is preferably selected from the group consisting of doughnuts, fried noodles, lardy cakes, Spritzkuchen, Krapfen, churros, bunuelos and xuxos. Most preferably, the ready-to-eat product is a doughnut.

The invention is further illustrated by means of the following, non-limiting examples.

EXAMPLES

Example 1 Ring doughnuts (45 grams) were prepared using the following recipe:

The doughnuts were proofed by placing them in a proofing cabinet for 60 minutes (35 °C, 70% relative humidity).

The proofed doughnuts were pre-fried on one side in a travelling fryer (20 sec. in oil with a temperature of 180°C) and transferred into a travelling infrared oven that had been additionally equipped with hot air impingement nozzles.

The oven consisted of a moving wire mesh belt the speed of which could be controlled. The hot air impingement nozzles were mounted at the front end of the oven both above and below the moving belt. The temperature of the hot air was adjustable. Four sets of infrared heating lamps were mounted above the moving belt and one set below. Each set of infrared heating lamps consisted of 4 lamps that were mounted at such angles that an even colouring of the products was obtained. The intensity of each heating set could be adjusted independently. The sets of lamps were evenly distributed across the length of the moving belt.

An experiment was carried out using the lamp intensities and impingement

temperatures depicted in Table I (zone 1 representing the first and zone 5 representing the last zone of the oven that the belt passes through). Average heat flow from the infrared heating lamps in Zone 2 - 5 was 15 kW/m ² . The average heat transfer coefficient in the hot air impingement section was 120 W/m ² .°C. Total residence time in the oven was 90 seconds. Residence time in impingement zone 1 was 15 seconds. Table I

Upon leaving the oven, the fully cooked doughnuts had a core temperature of about 95 °C. The baking loss observed during the cooking process was around 1 wt.%. In terms of appearance and eating quality the fully cooked doughnuts so obtained clearly show the chocolate chips at the surface of the doughnuts. The oil after frying did not show significant contamination.

Comparative Example 1 Ring doughnuts (45 grams) were prepared in the same way as described in Examples 1

The doughnuts were proofed by placing them in a proofing cabinet for 60 minutes (35 °C, 70% relative humidity).

The proofed doughnuts were fried on both sides in a travelling fryer (In total 120 sec. in oil with a temperature of 180°C). In terms of appearance and eating quality the fully cooked doughnuts so obtained lost all the chocolate chips at the surface of the doughnuts. The oil after frying showed significant contamination.