TECHNICAL FIELD

The present invention relates to the food processing technical field and particularly to a flour product, a preparation method thereof, and an application thereof.

BACKGROUND

Fried flour products refer to various food made using flour as the main ingredient and involve processes such as mixing, letting rise, shaping, and frying. These fried flour products include not only traditional snacks, such as Tianjin large fried dough twists and fried Sanzi, but also include leisure food produced by modem large industries such as flour-made polished glutinous rice strips, Sachima, and small fried dough twists.

Most flour products mentioned in the prior art are fried flour products. For example, cold- processed pastries such as Sachima mainly involve processes such as dough mixing, letting rise, cutting, frying, mixing with syrup, and shaping. As the dough needs to be cooked through frying, a considerable amount of oil enters into the dough during the process of frying and puffing and causes the product to have a higher fat content. Moreover, most manufacturers use palm oil because of the high frying stability and low costs, but palm oil also has a higher saturated fatty acid content, making up approximately 46% of the oil. At present, most studies are geared towards reducing fat absorption during frying using different methods. While these methods can reduce the fat content, they also affect the texture and cause Sachima to be hard and crunchy, which differs from the tender texture preferred by consumers.

Among existing non-fried flour products, breakthroughs have only occurred in the production of instant noodles. Progress is yet to be made in other non-fried flour products. The application of non- fried flour products in cold-processed pastries is an even rarer development.

SUMMARY

In order to overcome the disadvantages and drawbacks of the prior art, a first objective of the present invention is to provide a preparation method of a flour product, which employs a microwave puffing method instead of the existing frying method so as to reduce the flour product oil content and to avoid excessive intake of deep fried cooking oil by customers. The flour product made through microwave puffing has a porous structure. In an application of the flour product, the flour product has a tender texture comparable to fried cold-processed pastries such as Sachima when the flour product is mixed with syrup The preparation method is simple in operation, convenient in control, high in production efficiency, low in oil consumption, and can be used in large-scale production.

A second objective of the present invention is to provide a flour product, the flour product is prepared without frying and has a puffed volume that is 5-25 times the original volume. The flour product formed has a fine porous structure. In an application of the flour product, the flour product has a tender texture comparable to fried cold-processed pastries such as Sachima when the flour product is mixed with syrup

A third objective of the present invention is to provide an application of a flour product. The cold- processed pastry made from the flour product can serve as a substitute for existing cold-processed pastries that are processed again after fried. Furthermore, the cold-processed pastry made from the flour product has significantly lower oil content than traditional pastries and yet preserves the tender texture and egg aroma of cold-processed pastries. When the same amount of cold-processed pastries are consumed by a consumer, the cold-processed pastry of the present invention results in lower fat intake.

The first objective of the present invention is achieved through the following technical solution: a preparation method of a cold-processed pastry, comprising the following steps:

(51): resting the dough after cutting the dough to obtain a semi-finished product; and

(52) : microwaving the semi-finished product obtained in the step (S 1 ) so that the semi-finished product is puffed until the volume thereof becomes 5-25 times of the original volume, followed by discharging so as to obtain the flour product.

In the preparation method of a flour product according to the present invention, a microwave puffing method is employed instead of the existing frying method so as to lower the flour product oil content and reduce consumer intake of deep fried oil, which is conducive to healthy eating. The flour product made through microwave puffing has a porous structure (namely, fine compact pores). In an application of the flour product, the flour product has a tender texture comparable to fried cold-processed pastries such as Sachima when the flour product is mixed with syrup The preparation method is simple in operation, convenient in control, high in production efficiency, low in oil consumption, and can be used in large-scale production. In the step (SI), the resting is the last letting rise process of the dough. The resting enhances the dough malleability and facilitates full expansion of the dough volume, improves the internal structure of the dough such that the dough is light and porous after microwave puffing, and provides the necessary conditions for the step (S2) in which the semi-finished product is puffed until the volume thereof becomes several times of the original volume. More preferably, in the step (SI), the cutting the dough means cutting and/or shaping the dough into a specific shape, which is a regular pattern or an irregular pattern. The dough may be cut into, but not limited to, a strip or cake shape. The dough may also be shaped into, but not limited to, a granular, columnar, or star shape. In the step (S2), the puffed semi-finished product must be par-cooked before the flour product is discharged, so as to avoid overcooking the flour product which can lead to overbrowning. More preferably, in the step (S2), the semi-finished product obtained in the step (SI) is microwaved so that the semi finished product is puffed until the volume thereof becomes 5-15 times of the original volume, followed by discharging so as to obtain the flour product.

Preferably, in the step (S2), a microwave power of the microwaving is 50-500 kW.

Preferably, in the step (S2), the microwave power of the microwaving is 50-450 kW.

Preferably, in the step (S2), the microwave power of the microwaving is 100-400 kW.

Preferably, in the step (S2), the microwave power of the microwaving is 100-300 kW.

Preferably, in the step (S2), the microwave power of the microwaving is 50-200 kW.

Preferably, in the step (S2), a process duration of the microwaving is 15-90 s.

Preferably, in the step (S2), the process duration of the microwaving is 15-45 s.

Preferably, in the step (S2), the process duration of the microwaving is 40-80 s.

Preferably, in the step (S2), the process duration of the microwaving is 35-65 s.

Through the above technical solution, the semi-finished product is quickly puffed under the microwave power condition of 50-500 kW, and the semi-finished product expands within 15- 90 s until the volume thereof becomes 5-25 times of the original volume. More preferably, the microwave power of the microwaving is, but not limited to, 50-450 kW, 100-400 kW, 100-300 kW, 200-300 kW, 300-400 kW, or 50-200 kW; the process duration of the microwaving is, but not limited to, 15-90 s, 15-45 s, 35-50 s, 40-80 s or 35-65 s. The present invention is mainly applicable to industrialized production. The expansion factor of the flour product correlates with the microwave power, process duration, and the feed amount of the semi-finished product. The higher the feed amount of the semi-finished product, the higher the microwave power and longer the process duration, hence allowing the semi-finished product to expand to 5-25 times and preferably 5-15 times the original volume. If the feed amount of the semi-finished product is low, the microwave power is high, and the process duration is long, then the semi-finished product will easily become charred. In this process, the semi-finished product absorbs microwave energy, and the rapid internal temperature increase of the semi-finished product rapidly gasifies the moisture in the semi-finished product and expands the dough rapidly. In addition, because of the resting in the step (SI), the microwave-puffed flour product becomes light and porous. In the prior art, noodles absorb the heat energy of oil during the frying process, which gasifying the moisture in the noodles rapidly and thereby achieving expansion of the noodles. The duration of the frying process is longer than that of the microwave puffing in the present invention. High-temperature heating easily causes cis-fatty acids in the oil to isometrically transform into trans-fatty acids, which is harmful to consumers’ physical health. Further, in the step (S2), the environment where the puffing takes place is continuously dehumidified throughout the microwave puffing process to lower the humidity. The dehumidification is conducive to improved puffing efficiency and prevents water vapour from remaining in the flour product which can affect shaping and moisture removal.

Preferably, the step (S2) further comprises drying the puffed semi-finished product such that the water content thereof is lower than 10% of the total mass thereof after the discharging.

By drying and controlling the water content of the flour product to be lower than 10% of its total mass, shelf life is prolonged and spoilage and resulting odours are avoided. More preferably, the step (S2) further comprises drying the puffed semi-finished product such that the water content thereof is lower than 7% of the total mass thereof after the discharging. Most preferably, the step (S2) further comprises drying the puffed semi-finished product such that the water content thereof is lower than 5% of the total mass thereof after the discharging. Further, a drying condition is air drying for 5-10 min at a temperature of 105-110°C. In an embodiment, the process of the present invention comprises a set of step of subjecting the flour product to a treatment with a hot gas. In an embodiment, the gas is preferably air. In an embodiment the gas is at a temperature of 75-200°C, preferably 100-175°C, more preferably 110- 150°C and more preferably 125-140°C. In an embodiment, the gas is blown over the flour product, preferably at a speed of 1000-25000 m ³ /h, preferably 5000-20000 m ³ /h, more preferably 8000- 18000 m ³ /h. In a preferred embodiment, the microwave treatment is used in conjunction with a hot gas treatment step, wherein the gas is at a temperature of75-200°C at a speed of 1000-25000 m ³ /h. This treatment step improves the puffing process of the present invention.

Preferably, in the step (SI), a temperature of the resting is 25-38°C.

Preferably, in the step (SI), the temperature of the resting is 28-35°C.

Preferably, in the step (SI), a relative humidity during the resting is 80-90%.

Preferably, in the step (SI), the relative humidity during the resting is 85-90%.

Preferably, in the step (SI), the relative humidity during the resting is 80-86%.

Preferably, in the step (SI), a duration of the resting is 1-5 h.

Preferably, in the step (SI), the duration of the resting is 2-4 h.

In the above technical solution, the last letting rise process is implemented to the dough to enhance dough malleability and facilitates full expansion of the dough volume, improve the internal structure of the dough such that the dough is light and porous after microwave puffing, and provide the necessary conditions for the step (S2) in whicn the semi-finished product is puffed until the volume thereof becomes several times of the original volume. The temperature of the resting is controlled at 25-38°C, and more preferably at 28-35°C, 25-30°C, 32-38°C or 30-32°C to avoid slowing down the letting rise process and a reduced puffed dough volume caused by an overly low temperature. Reduction or loss of the letting rise effect caused by an overly high temperature is also avoided. The relative humidity during the resting is controlled at 80-90% and is more conducive to the letting rise of the dough; more preferably, the resting is controlled at 85-90%, 80-86%, 83-86%, or 85-90%. Controlling the time of the resting is equally important, because it directly influences the puffing ratio of the flour product. When the time of the resting is inadequate, the puffing ratio is lower than 2 times of the original volume and the puffing effect fails to meet the industrialization requirements for the flour product of the present invention, and the texture is severely impacted. More preferably, the time of the resting is 2-4 h, 3-4 h or 3-5 h.

Preferably, the step (SI) further comprises the following: first pressing the dough into a sheet, followed by letting rise, and then pressing the dough into a sheet again prior to cutting the dough.

More preferably, the dough is first pressed into a sheet, then the dough is let rise for 1 -3 h at 28- 35°C, followed by pressing the dough again prior to cutting the dough such that the dough has a thickness of 1 -2 mm, thereby relaxing the dough and enhancing the air holding capacity. Further, after pressing the dough into a sheet, the sheet can continue to rise for 1-2 h at a temperature of 28-35°C. Most preferably, the dough is first pressed into a sheet, then is let rise for 1 -2 h at a temperature of 30-32°C, followed by pressing the dough again prior to cutting the dough such that the dough has a thickness of 1 -2 mm.

Preferably, in the step (SI), the dough comprises the following ingredients in parts by weight:

Flour 420-450 parts

Beaten egg liquid 160-270 parts

Gluten powder 20-28 parts Yeast powder 3-7 parts

Leavening agent 3-5 parts

Other auxiliary ingredients 8-20 parts

Water 70-90 parts.

The dough of the present invention uses flour and beaten egg liquid as the main ingredients; gluten powder, yeast powder, leavening agent, other auxiliary ingredients, and water are added therein and mixed to form the dough. The flour product prepared with the dough in combination with the operations in the steps (SI) and (S2) can achieve the effects of 5-25 times volume expansion, tender and melty texture, and rich egg aroma. Gluten powder has excellent malleability and improves processability of the dough. When mixed with flour, gluten powder can improve the following for the dough: gluten content; mixability; processability; air preservation used for expansion control; volume; evenness; and texture. Yeast powder releases carbon dioxide during the processes of dough letting rise, resting, or microwave puffing, which is condusive to puffing of the flour product and imparts a light and porous effect to the flour product without affecting the flavour of the products. The synergistic effect of the puffing agent and the yeast powder promotes puffing of the flour product so that the dough develops a compact porous structure in the process of microwave puffing. Further, the flour is bread flour; the dough also comprises 0.002-0.008 part by weight of food enzymes, which at least include amylase, hemicellulase and lipase. The food enzymes can improve the dough malleability and significantly improve the quality of the dough product. During the letting rise and resting of the dough, macromolecular substances in the dough are degraded into micromolecular substances that are convenient for absorption by human bodies, which promote nutrients absorption of the flour product by human bodies. More preferably, in the step (SI), the dough comprises the following ingredientin parts by weight:

Flour 440-450 parts

Beaten egg liquid 200-230 parts

Gluten powder 22-25 parts

Yeast powder 4-6 parts

Leavening agent 3-4 parts

Other auxiliary ingredients 8-15 parts

Water 80-90 parts.

Preferably, the leavening agent is sodium bicarbonate and/or ammonium bicarbonate.

More preferably, the leavening agent is sodium bicarbonate mixed with ammonium bicarbonate in a ratio by weight of 1.5-2.0:2.5-3.0. Sodium carbonate, water, carbon dioxide and ammonia gas are produced through thermal decomposition during the microwave heating process. Water is further heated to become steam. Together with carbon dioxide and ammonia gas, the steam makes flour product more fluffy and improves the texture. The leavening agent is made by mixing sodium bicarbonate with ammonium bicarbonate according to the above ratio. The above ratio prevents an excessive amount of sodium carbonate from remaining in the flour product, which can cause the flour product to have an alkaline taste and affects the texture of the flour product.

Preferably, the other auxiliary ingredients are sweetening agents and/or fruit-vegetable powders. Sweetening agents are added to improve the texture. Fruit-vegetable powders are added to provide colours and tastes of various fruits and vegetables to the flour product, so as to prevent the flour product from discoloring due to prolonged deep frying. More preferably, the sweetening agent is high malt syrup, maltitol, white granulated sugar, or trehalose. The dough further comprises 1 -20 parts by weight of cereal flour, which at least includes oat flour, buckwheat flour, quinoa flour, chickpea flour, purple potato flour or red bean flour, to improve the nutritional value of flour product. The dough further comprises 20-28 parts by weight of skimmed milk powder, which not only improves the milk aroma and nutritional value of the flour product, but also improves water absorption power of the dough, thereby reducing the possibility that the dough is not agglomerated, improving the dough resistance and strength, and lessening the phenomenon of overmixing. Moreover, the fat content of the skim milk powder is about 1%, which is much lower than that of ordinary milk powder, such that fat intake is reduced.

Preferably, the preparation method of the dough further comprises the following steps:

(Tl): weighing the flour, beaten egg liquid, gluten powder, yeast powder, leavening agent, other auxiliary ingredients, and water in parts by weight for later use; and

(T2): dry mixing the flour, gluten powder, yeast powder, and leavening agent for a certain duration, followed by adding and stirring the beaten egg liquid, other auxiliary ingredients, and water to form a lump, so as to obtain the dough.

The dough prepared through the above solution has more uniformly distributed ingredients. In the step (T2), dry mixing is performed first to allow the ingredients to be distributed uniformly in advance. Doing so prevents adding all the ingredients at once directly into the lump, which can greatly reduce the distribution uniformity of the dough. Further, in the step (T2), the dry mixing condition is mixing for 1 -2 min at a rotation speed of 18-40 rpm; the stirring agglomeration condition is pre-stirring for 1 - 3 min at a rotation speed of 18-40 rpm, and then further stirring for 3-5 min at an increased rotation speed of 40-100 rpm.

The second objective of the present invention is achieved through the following technical solution: a flour product, the flour product prepared through the above preparation method of the flour product. The flour product of the present invention is prepared without oil, so the oil content in the flour product is lower and excessive intake of deep fried oil by consumers is avoided. The volume after puffing is 5-25 times the original volume. The flour product formed has a fine porous structure. In an application of the flour product, the flour product has a tender texture comparable to fried cold-processed pastries such as Sachima when the flour product is mixed with syrup.

The third objective of the present invention is achieved through the following technical solution: an application of the flour product prepared through the above preparation method of the flour product, wherein the flour product is applied to a cold-processed pastry.

In an application of a flour product of the present invention, the flour product is applied to a cold-processed pastry and can serve as a substitute for existing cold-processed pastries that are processed again after being fried, and can greatly reduce the oil content of the traditional pastries while maintaining the tender texture and egg aroma of cold-processed pastries. When the same amount of cold-processed pastries are consumed by a consumer, the cold-processed pastry of the present invention results in lower fat intake.

Preferably, the preparation method of the cold-processed pastry comprises the following steps:

(Rl): acquiring cooking oil, flavoured syrup, and the flour product for later use;

(R2): heating the cooking oil and then adding the cooking oil to the flour product; and

(R3): heating the flavoured syrup, followed by mixing the flavoured syrup with the flour product processed in the step (R2) to coat surfaces of the flour product with the flavoured syrup, so as to obtain the cold-processed pastry.

Preferably, in the step (R2), the cooking oil is heated to 30-65°C.

Preferably, in the step (R2), the cooking oil is heated to 40-60°C.

Preferably, in the step (R2), the cooking oil is heated to 55-65°C.

Preferably, in the step (R2), the cooking oil is added in an amount that is 25-100% of the weight of the flour product from the step (Rl).

Preferably, in the step (R2), the cooking oil is added in an amount that is 25-30% of the weight of the flour product from the step (Rl). Preferably, in the step (R2), the cooking oil is added in an amount that is 35-45% of the weight of the flour product from the step (Rl).

The cold-processed pastry prepared with the above preparation method has a tender and melty texture comparable with the existing Sachima. Moreover, this method can greatly reduce the oil content of traditional pastries while maintaining the tender texture and egg aroma of cold- processed pastries. When the same amount of cold-processed pastries are consumed by a consumer, the cold-processed pastry of the present invention results in lower fat intake. In the step (R2), the temperature of the cooking oil is up to 65 °C as the maximum, and is preferably 30-65°C, 40-60°C, 45-50°C or 55-65°C. The purpose of heating is to allow the oil to have improved fluidity compared with that at room temperature and allow the oil to more easily adhere to the surface of the flour product. The amount of oil added in the present invention is controllable, which is different from the existing fried flour product with a large amount of oil infdtrated therein; the reduced oil intake into the body is more conducive to human well-being. More preferably, the cooking oil is added by spraying; the cooking oil is a vegetable oil that can be selected from the group consisting of rice oil, corn oil, sunflower seed oil, peanut oil, olive oil, flaxseed oil, or tea seed oil. The vegetable oils mentioned above have low saturated fatty acid content and high unsaturated fatty acid content. Cis-fatty acids of the unsaturated fatty acids essentially does not isometrically transform into trans-fatty acids below 65°C, and thus the flour product would be healthier to eat. The application amount of cooking oil is 25-100%, preferably 25-30%, 28-32%, 50-60%, 65-80%, 90-100%, or 35-45% with respect to the weight of the flour product in the step (Rl). The application amount of the cooking oil is controllable; choosing to use less cooking oil not only ensures the texture, but also reduces cooking oil intake and is more beneficial to consumers’ health. In the step (R3), the flavoured syrup is heated to 60-100°C to improve the fluidity of the flavoured syrup so that it can be more easily coated on the surface of the flour product. More preferably, the flavoured syrup is mixed with the flour product processed in the step (R2) at a ratio by weight of 7-8:10.

The microwave puffing of the dough according to the present invention is essentially different from the existing starch puffing. According to the present invention, a cold-processed pastry is made from a flour product obtained through microwave puffing a dough which uses flour as the main ingredient. Although puffing is difficult and many factors need to be taken into account during puffing, the cold- processed pastry made from the puffed flour product of the present invention has a tenderer texture and a lower oil content compared with flour products puffed by frying. If the flour used in the invention is simply replaced with starch and then the dough is processed with microwave according to the steps of the present invention, the puffing effect would not be obvious; only a cooked outcome can be achieved. Even after processing, a cold-processed pastry with a tender texture of the invention still cannot be obtained. The existing stach products requires extrusion puffing to achieve the puffing effect, but it is completely different from the microwave puffing technology of the present invention.

Beneficial effects of the present invention include of the following: the preparation method of the flour product of the present invention employs a microwave puffing method instead of the existing frying method so as to reduce the flour product oil content and to avoid excessive intake of deep fried cooking oil by customers. The flour product made through microwave puffing has a porous structure. In an application of the flour product, the flour product has a tender texture comparable to fried cold-processed pastries such as Sachima when the flour product is mixed with syrup The preparation method is simple in operation, convenient in control, high in production efficiency, low in oil consumption, and can be used in large-scale production.

The flour product of the present invention is prepared without frying and has a puffed volume that is 5-25 times the original volume. The flour product formed has a fine porous structure. In an application of the flour product, the flour product has a tender texture comparable to fried cold-processed pastries such as Sachima when the flour product is mixed with syrup

In an application of a flour product of the present invention, the flour product is applied to a cold- processed pastry and can serve as a substitute for the existing cold-processed pastries that are processed again after frying, and can greatly reduce the oil content of traditional pastries while maintaining the tender texture and egg aroma of cold-processed pastries. When the same amount of cold-processed pastries are consumed by a consumer, the cold-processed pastry of the present invention results in lower fat intake.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a first comparison photograph of the flour product according to the present invention before and after puffing;

FIG. 2 is a comparison photograph from another perspective of the flour product before and after puffing; FIG. 3 is a second comparison photograph of the flour product according to the present invention before and after puffing;

FIG. 4 is a third comparison photograph of the flour product according to the present invention before and after puffing;

FIG. 5 is a fourth comparison photograph of the flour product according to the present invention before and after puffing;

FIG. 6 is a fifth comparison photograph of the flour product according to the present invention before and after puffing;

FIG. 7 is a sixth comparison photograph of the flour product according to the present invention before and after puffing;

FIG. 8 is a seventh comparison photograph of the flour product according to the present invention before and after puffing;

FIG. 9 is an eighth comparison photograph of the flour product according to the present invention before and after puffing;

FIG. 10 is a ninth comparison photograph of the flour product according to the present invention before and after puffing;

FIG. 11 is a tenth comparison photograph of the flour product according to the present invention before and after puffing;

FIG. 12 is an eleventh comparison photograph of the flour product according to the present invention before and after puffing; and

FIG. 13 is a puffed outcome photograph of the flour product prepared with different resting durations according to Embodiment 1 of the present invention.

DETAILED DESCRIPTION

To facilitate understanding by those skilled in the art, the present invention is further described below in combination with embodiments and accompanying drawings; the contents mentioned in the embodiments do not limit the present invention.

Embodiment 1 A preparation method of a flour product, comprising the following steps:

(51): resting the dough after cutting the dough to obtain a semi-finished product; and

(52) : microwaving the semi-finished product obtained in the step (S 1 ) so that the semi-finished product is puffed until the volume thereof becomes 5-15 times of the original volume, followed by discharging so as to obtain the flour product.

In the step (SI), the cutting the dough was cutting the dough into strips; and the step (SI) further comprises: first pressing the dough into a sheet, then letting rise for 1.5 h at a temperature of33°C, and then pressing the dough again prior to cutting the dough such that the dough has a thickness of 1.5 mm.

In the step (S2), the puffed semi-finished product should be par-cooked before discharging.

In the step (S2), the microwave power of the microwaving was 150 kW.

In the step (S2), the process duration of the microwaving was 50 s.

In the step (S2), the puffing environment was continuously dehumidified throughout the microwave puffing process.

The step (S2) further comprises drying the puffed semi-finished product such that the water content thereof is lower than 7% of the total mass thereof after the discharging. The drying condition was air drying for 8 min at 108°C.

In the step (SI), the temperature of the resting was 33°C.

In the step (SI), the relative humidity during the resting was 85%.

In the step (SI), the duration of the resting was 3 h.

In the step (SI), the dough comprises the following ingredients in parts by weight:

Flour 430 parts

Beaten egg liquid 230 parts

Gluten powder 24 parts

Yeast powder 5 parts

Leavening agent 4 parts

Other auxiliary ingredients 14 parts Water 80 parts.

The flour was bread flour.

The leavening agent was a mixture of sodium bicarbonate and ammonium bicarbonate at a ratio by weight of 1.8:2.8; and the other auxiliary ingredients were mixtures of sweetening agents and fruit- vegetable powders at a ratio by weight of 9:5.

The sweetening agent was high malt syrup.

The preparation method of the dough comprised the following steps:

(Tl): weighing the flour, beaten egg liquid, gluten powder, yeast powder, leavening agent, other auxiliary ingredients, and water in parts by weight for later use; and

(T2): dry mixing the flour, gluten powder, yeast powder, and leavening agent for a certain duration, followed by adding and stirring the beaten egg liquid, other auxiliary ingredients, and water to form a lump, so as to obtain the dough.

In the step (T2), the dry mixing condition was mixing for 1.5 min at a rotation speed of 30 rpm; the stirring agglomeration condition was pre-stirring for 2 min at a rotation speed of 30 rpm, and then further stirring for 4 min at an increased rotation speed of 70 rpm.

As shown in FIG. 4, FIG. 1 1 or FIG. 12, a flour product was prepared through the above preparation method of a flour product.

The application of a flour product prepared through the above preparation method thereof; the flour product being applied in a cold-processed pastry.

The preparation method of the cold-processed pastry comprised the following steps of:

(Rl): acquiring cooking oil, flavoured syrup, and the flour product for later use;

(R2): heating the cooking oil and then spraying the cooking oil onto the flour product; and

(R3): heating the flavoured syrup, followed by mixing the flavoured syrup with the flour product processed in the step (R2) to coat surfaces of the flour product with the flavoured syrup, so as to obtain the cold-processed pastry.

In the step (R2), the cooking oil was heated to 60°C. The cooking oil was added in an amount that was 50% of the weight of the flour product in the step (Rl).

In the step (R3), the flavoured syrup was heated to 80°C, and the flavoured syrup was mixed with the flour product processed in the step (R2) at a weight ratio of 7.5: 10.

Embodiment 2

A preparation method of a flour product, comprising the following steps:

(51): resting the dough after cutting the dough to obtain a semi-finished product; and

(52) : microwaving the semi-finished product obtained in the step (S 1 ) so that the semi-finished product is puffed until the volume thereof becomes 5-15 times of the original volume, followed by discharging so as to obtain the flour product.

In the step (SI), the cutting the dough was cutting the dough into cake shapes; and the step (SI) further comprising: first pressing the dough into a sheet, then letting rise for 2 h at a temperature of 28°C, and then pressing the dough again prior to cutting the dough such that the dough has a thickness of 1 mm.

In the step (S2), the puffed semi-finished product should be par-cooked before discharging.

In the step (S2), the microwave power of the microwaving was 50 kW.

In the step (S2), the process duration of the microwaving was 65 s.

In the step (S2), the puffing environment was continuously dehumidified throughout the microwave puffing process.

The step (S2) further comprises drying the puffed semi-finished product such that the water content thereof is lower than 7% of the total mass thereof after the discharging. The drying condition was air drying for 10 min at 105°C.

in the step (SI), the temperature of the resting was 28°C.

In the step (SI), the relative humidity during the resting was 80%.

In the step (SI), the duration of the resting was 5 h.

In the step (SI), the dough comprises the following ingredients in parts by weight:

Flour 420 parts Beaten egg liquid 220 parts

Gluten powder 28 parts

Yeast powder 3 parts

Leavening agent 3 parts

Other auxiliary ingredients 8 parts

Water 70 parts.

The flour was bread flour.

The leavening agent was a mixture of sodium bicarbonate and ammonium bicarbonate at a ratio by weight of 1.5:3.0, and the other auxiliary ingredients were sweetening agents.

The sweetening agent was maltitol.

The preparation method of the dough comprised the following steps:

(Tl): weighing the flour, beaten egg liquid, gluten powder, yeast powder, leavening agent, other auxiliary ingredients, and water in parts by weight for later use; and

(T2): dry mixing the flour, gluten powder, yeast powder, and leavening agent for a certain duration, followed by adding and stirring the beaten egg liquid, other auxiliary ingredients, and water to form a lump, so as to obtain the dough.

In the step (T2), the dry mixing condition was mixing for 2 min at a rotation speed of 18 rpm; and the stirring agglomeration condition was pre-stirring for 3 min at a rotation speed of 18 rpm, and then further stirring for 5 min at a rotation speed of 40 rpm.

As shown in FIGs. 1 to 2, a flour product was prepared through the above preparation method of the flour product.

The application of a flour product prepared through the above preparation method thereof, the flour product being applied in a cold-processed pastry.

The preparation method of the cold-processed pastry comprised the following steps:

(Rl): acquiring cooking oil, flavoured syrup, and the flour product for later use;

(R2): heating the cooking oil and then adding the cooking oil to the flour product; and (R3): heating the flavoured syrup, followed by mixing the flavoured syrup with the flour product processed in the step (R2) to coat surfaces of the flour product with the flavoured syrup, so as to obtain the cold-processed pastry.

In the step (R2), the cooking oil was heated to 55°C.

The cooking oil was added in an amount that was 25% of the weight of the flour product of the step (Rl).

In the step (R3), the flavoured syrup was heated to 60°C; and the flavoured syrup was mixed with the flour product processed in the step (R2) at a weight ratio of 7: 10.

Embodiment 3

A preparation method of a flour product, comprising the following steps:

(51): resting the dough after cutting the dough to obtain a semi-finished product; and

(52): microwaving the semi-finished product obtained in the step (SI) so that the semi-finished product is puffed until the volume thereof becomes 5-15 times of the original volume, followed by discharging so as to obtain the flour product.

In the step (SI), the cutting the dough was cutting the dough and then shaping into particles; and the step (SI) further comprising: first pressing the dough into a sheet, then letting rise for 1 h at a temperature of 35°C, and then pressing the dough again prior to cutting the dough such that the dough has a thickness of 2 mm.

In the step (S2), the puffed semi-finished product should be par-cooked before discharging.

In the step (S2), the microwave power of the microwaving was 200 kW.

In the step (S2), the process duration of the microwaving was 35 s.

In the step (S2), the puffing environment was continuously dehumidified throughout the microwave puffing process.

The step (S2) further comprises drying the puffed semi-finished product such that the water content thereof is lower than 7% of the total mass thereof after the discharging. The drying condition was air drying for 5 min at 110°C.

In the step (SI), the temperature of the resting was 35°C. In the step (SI), the relative humidity during the resting was 90%.

In the step (SI), the duration of the resting was 1.2 h.

In the step (SI), the dough comprises the following ingredients in parts by weight:

Flour 450 parts

Beaten egg liquid 240 parts

Gluten powder 20 parts

Yeast powder 7 parts

Leavening agent 5 parts

Other auxiliary ingredients 20 parts

Water 90 parts.

The flour was bread flour.

The leavening agent was a mixture of sodium bicarbonate and ammonium bicarbonate at a ratio by weight of 2.0:2.5; and the other auxiliary ingredients were fruit-vegetable powders.

The preparation method of the dough comprised the following steps:

(Tl): weighing the flour, beaten egg liquid, gluten powder, yeast powder, leavening agent, other auxiliary ingredients, and water in parts by weight for later use; and

(T2): dry mixing the flour, gluten powder, yeast powder, and leavening agent for a certain duration, followed by adding and stirring the beaten egg liquid, other auxiliary ingredients, and water to form a lump, so as to obtain the dough.

In the step (T2), the dry mixing condition was mixing for 1 min at a rotation speed of 40 rpm; and the stirring agglomeration condition was pre-stirring for 1 min at a rotation speed of 40 rpm, and then further stirring for 3 min at an increased rotation speed of 100 rpm.

A flour product, prepared through the above preparation method of a flour product.

The application of a flour product prepared through the above preparation method thereof, the flour product being applied in a cold-processed pastry.

The preparation method of the cold-processed pastries comprised the following steps of: (Rl): acquiring cooking oil, flavoured syrup, and the flour product for later use;

(R2): heating the cooking oil and then adding the cooking oil to the flour product; and

(R3): heating the flavoured syrup, followed by mixing the flavoured syrup with the flour product processed in the step (R2) to coat surfaces of the flour product with the flavoured syrup, so as to obtain the cold-processed pastry.

In the step (R2), the cooking oil was heated to 65°C.

The cooking oil was added in an amount that was 100% of the weight of the flour product of the step (Rl).

In the step (R3), the flavoured syrup was heated to 100°C; and the flavoured syrup was mixed with the flour product processed in the step (R2) at a weight ratio of 8: 10.

Embodiment 4

A preparation method of a flour product, comprising the following steps:

(51): resting the dough after cutting the dough to obtain a semi-finished product; and

(52) : microwaving the semi-finished product obtained in the step (S 1 ) so that the semi-finished product is puffed until the volume thereof becomes 5-15 times of the original volume, followed by discharging so as to obtain the flour product.

In the step (S 1 ), the cutting the dough means cutting the dough and shaping into a pentagram shape. In the step (S2), the microwave power of the microwaving was 150 kW.

In the step (S2), the process duration of the microwaving was 40 s.

The step (S2) further comprises drying the puffed semi-finished product such that the water content thereof is lower than 7% of the total mass thereof after the discharging.

In the step (SI), the temperature of the resting was 34°C.

The relative humidity during the resting was 88%.

In the step (SI), the duration of the resting was 3 h.

In the step (SI), the dough comprises the following ingredients in parts by weight:

Flour 440 parts Beaten egg liquid 225 parts

Gluten powder 23 parts

Yeast powder 6 parts

Leavening agent 5 parts

Other auxiliary ingredients 16 parts

Water 78 parts.

The flour was bread flour.

The leavening agent was a mixture of sodium bicarbonate and ammonium bicarbonate at a ratio by weight of 1.6:2.8; and the other auxiliary ingredients were sweetening agents.

The sweetening agent was trehalose.

The preparation method of the dough comprised steps of:

(Tl): weighing the flour, beaten egg liquid, gluten powder, yeast powder, leavening agent, other auxiliary ingredients, and water in parts by weight for later use; and

(T2): dry mixing the flour, gluten powder, ferment powder, and leavening agent for 2 min, followed by addition of beaten egg liquid, other auxiliary ingredients, and water and stirring for agglomeration so as to obtain the dough.

As shown in FIG. 3, a flour product was prepared through the above preparation method of a flour product.

The application of a flour product prepared through the above preparation method thereof, the flour product being applied in a cold-processed pastry.

The preparation method of the cold-processed pastry comprised the following steps of:

(Rl): acquiring cooking oil, flavoured syrup and the flour product for later use;

(R2): heating the cooking oil and then adding the cooking oil to the flour product; and

(R3): heating the flavoured syrup, then mixing the flavored syrup with the flour product processed in the step (R2) to coat the surfaces of the flour product with the flavoured syrup, so as to obtain the cold-processed pastry. In the step (R2), the cooking oil was heated to 58°C.

The cooking oil was added in an amount that was 30% of the weight of the flour product of the step (Rl).

Embodiment 5

A preparation method of a flour product, comprising the following steps:

(51): resting the dough after cutting the dough to obtain a semi-finished product; and

(52) : microwaving the semi-finished product obtained in the step (S 1 ) so that the semi-finished product is puffed until the volume thereof becomes 5-25 times of the original volume, followed by discharging so as to obtain the flour product.

In the step (SI), the cutting the dough meant cutting the dough and shaping into a gear shape.

In the step (S2), the microwave power of the microwaving was 450 kW.

In the step (S2), the process duration of the microwaving was 90 s.

Step (S2) further comprises drying the puffed semi-finished product such that the water content thereof is lower than 10% of the total mass thereof after the discharging.

In the step (S2), the puffed semi-finished product should be par-cooked before discharging.

In the step (SI), the temperature of the resting was 38°C.

In the step (SI), the relative humidity during the resting was 82%.

In the step (SI), the duration of the resting was 4.5 h.

Step (SI) further comprising: first pressing the dough into a sheet, followed by leavening for 1.9 h at a temperature of 28°C, and then pressing the dough into a sheet again prior to cutting the dough.

In the step (SI), the dough comprises the following ingredients in parts by weight:

Flour 425 parts

Beaten egg liquid 160 parts

Gluten powder 21 parts Yeast powder 4 parts

Leavening agent 3.2 parts

Other auxiliary ingredients 9 parts

Water 72 parts.

The flour was bread flour; and the food enzyme formulation was a mixture of amylase, hemicellulase and lipase at an enzyme activity ratio of 4:2: 1.

The leavening agent was sodium bicarbonate.

The other auxiliary ingredients were mixtures of sweetening agents and fruit-vegetable powders at a ratio by weight of 9:5.

The sweetening agent was high malt syrup. The dough further comprised 5 parts by weight of cereal flour; the cereal flour was oat flour.

The dough further comprised 25 parts by weight of skimmed milk powder.

The dough further comprised 0.008 part by weight of a food enzyme formulation.

The preparation method of the dough comprised the following steps:

(Tl): weighing the flour, beaten egg liquid, gluten powder, ferment powder, leavening agent, food enzyme formulation, cereal flour, skimmed milk powder, other auxiliary ingredients, and water in parts by weight for later use; and

(T2): dry mixing the flour, gluten powder, ferment powder, and leavening agent for a certain duration, followed by addition of beaten egg liquid, food enzyme formulation, cereal flour, skimmed milk powder, other auxiliary ingredients and water and stirring for agglomeration so as to obtain the dough.

In the step (T2), the dry mixing condition was mixing for 1.2 min at a rotation speed of 19 rpm; and the stirring agglomeration condition was pre-stirring for 1.2 min at a rotation speed of 39 rpm, and then further stirring for 3.2 min at an increased rotation speed of 90 rpm.

A flour product, prepared through the above preparation method of the flour product.

The application of the above flour product, wherein the flour product is applied to a cold- processed pastry.

The preparation method of the cold-processed pastry comprised the following steps: (Rl): acquiring cooking oil, flavoured syrup and the flour product for later use;

(R2): heating the cooking oil and then adding the cooking oil to the flour product; and

(R3): heating the flavoured syrup, followed by mixing the flavoured syrup with the flour product processed in the step (R2) to coat surfaces of the flour product with the flavoured syrup, so as to obtain the cold-processed pastry.

In the step (R2), the cooking oil was heated to 56°C.

The cooking oil was added in an amount that was 42% of the weight of the flour product of the step (Rl).

In the step (R3), the flavoured syrup was heated to 62°C; and the flavoured syrup was mixed with the flour product processed in the step (R2) at a weight ratio of 7.2: 10.

Embodiment 6

A preparation method of a flour product, comprising the following steps:

(51): resting the dough after cutting the dough to obtain a semi-finished product; and

(52) : microwaving the semi-finished product obtained in the step (S 1 ) so that the semi-finished product is puffed until the volume thereof becomes 5-25 times of the original volume, followed by discharging so as to obtain the flour product.

In the step (SI), the cutting the dough meant shaping the dough into a cat's claw shape.

In the step (S2), the microwave power of the microwaving was 500 kW.

In the step (S2), the process duration of the microwaving was 15 s.

Step (S2) further comprises drying the puffed semi-finished product such that the water content thereof is lower than 10% of the total mass thereof after the discharging.

In the step (S2), the puffed semi-finished product should be par-cooked before discharging.

In the step (SI), the temperature of the resting was 25°C.

In the step (SI), the relative humidity during the resting was 88%.

In the step (SI), the duration of the resting was 1.5 h. Step (SI) further comprising: first pressing the dough into a sheet, followed by letting rise for 1.2 h at a temperature of 34°C, and then pressing the dough into a sheet again prior to cutting the dough.

In the step (SI), the dough comprises the following ingredients in parts by weight:

Flour 445 parts

Beaten egg liquid 270 parts

Gluten powder 27 parts

Yeast powder 6.8 parts

Leavening agent 4.8 parts

Other auxiliary ingredients 19 parts

Water 88 parts.

The flour was bread flour; and the food enzyme formulation was a mixture of amylase, hemicellulase, and lipase at an enzyme activity ratio of 4:2:1.

The leavening agent was ammonium bicarbonate.

The other auxiliary ingredients were sweetening agents.

The sweetening agent was maltitol. The dough further comprised 1 part by weight of cereal flour; the cereal flour was red bean powder.

The dough further comprised 20 parts by weight of skimmed milk powder.

The dough further comprised 0.006 part by weight of a food enzyme formulation.

The preparation method of the dough comprised steps of:

(Tl): weighing the flour, beaten egg liquid, gluten powder, ferment powder, leavening agent, food enzyme formulation, skimmed milk powder, cereal flour, other auxiliary ingredients and water in parts by weight for later use; and

(T2): dry mixing the flour, gluten powder, ferment powder and leavening agent for a certain duration, followed by addition of beaten egg liquid, food enzyme formulation, skimmed milk powder, cereal flour, other auxiliary ingredients, and water and stirring for agglomeration so as to obtain the dough. In the step (T2), the dry mixing condition was mixing for 1.8 min at a rotation speed of 38 rpm; and the stirring agglomeration condition was pre-stirring for 2.8 min at a rotation speed of 20 rpm, and then further stirring for 4.8 min at an increased rotation speed of 45 rpm.

A flour product, prepared through the above preparation method of a flour product.

The application of the above flour product, wherein the flour product is applied to a cold- processed pastry.

The preparation method of the cold-processed pastry comprised the following steps:

(Rl): acquiring cooking oil, flavoured syrup, and the flour product for later use;

(R2): heating the cooking oil and then adding the cooking oil to the flour product; and

(R3): heating the flavoured syrup, followed by mixing the flavoured syrup with the flour product processed in the step (R2) to coat surfaces of the flour product with the flavoured syrup, so as to obtain the cold-processed pastry.

In the step (R2), the cooking oil was heated to 30°C.

The cooking oil was added in an amount that was 60% of the weight of the flour product of the step (Rl).

In the step (R3), the flavoured syrup was heated to 98°C; and the flavoured syrup was mixed with the flour product processed in the step (R2) at a weight ratio of 7.8 : 10.

Embodiment 7

A preparation method of a flour product, comprising the following steps:

(51): resting the dough after cutting the dough to obtain a semi-finished product; and

(52): microwaving the semi-finished product obtained in the step (S 1) so that the semi-finished product is puffed until the volume thereof becomes 5-25 times of the original volume, followed by discharging so as to obtain the flour product.

In the step (SI), the cutting the dough meant cutting the dough into a strip shape.

In the step (S2), the microwave power of the microwaving was 400 kW.

In the step (S2), the process duration of the microwaving was 80 s. Step (S2) further comprises drying the puffed semi-finished product such that the water content thereof is lower than 10% of the total mass thereof after the discharging.

In the step (S2), the puffed semi-finished product should be par-cooked before discharging.

In the step (SI), the temperature of the resting was 29°C.

In the step (SI), the relative humidity during the resting was 83%.

In the step (SI), the duration of the resting was 4 h.

Step (SI) further comprising: first pressing the dough into a sheet, followed by letting rise for 1.6 h at a temperature of 33°C, and then pressing the dough into a sheet again prior to cutting the dough.

In the step (SI), the dough comprises the following ingredients in parts by weight:

Flour 445 parts

Beaten egg liquid 180 parts

Gluten powder 26 parts

Yeast powder 8 parts

Leavening agent 2 parts

Food enzyme formulation 0.006 part

Other auxiliary ingredients 12 parts

Water 83 parts.

The flour was bread flour; and the food enzyme formulation was a mixture of amylase, hemicellulase, and lipase at an enzyme activity ratio of 4:3 :1.

The leavening agent is comprised of sodium bicarbonate and ammonium bicarbonate at a ratio by weight of 1 : 1.

The other auxiliary ingredients were fruit-vegetable powders.

The dough further comprised 20 parts by weight of cereal flour; the cereal flour was a mixture of oat flour, buckwheat flour, and purple potato flour at a ratio by weight of 3 :1 :1.

The dough further comprised 28 parts by weight of skimmed milk powder. The dough further comprised 0.002 part by weight of a food enzyme formulation.

The preparation method of the dough comprised steps of:

(Tl): weighing the flour, beaten egg liquid, gluten powder, ferment powder, leavening agent, food enzyme formulation, other auxiliary ingredients, and water in parts by weight for later use; and

(T2): dry mixing the flour, gluten powder, ferment powder, and leavening agent for a certain duration, followed by addition of beaten egg liquid, food enzyme formulation, other auxiliary ingredients, and water and stirring for agglomeration so as to obtain the dough.

In the step (T2), the dry mixing condition was mixing for 1.4 min at a rotation speed of 37 rpm; and the stirring agglomeration condition was pre-stirring for 2.2 min at a rotation speed of 28 rpm, and then further stirring for 4.6 min at an increased rotation speed of 75 rpm.

A flour product, prepared through the above preparation method of a flour product.

The application of the above flour product, wherein the flour product is applied to a cold- processed pastry.

The preparation method of the cold-processed pastry comprised the following steps:

(Rl): acquiring cooking oil, flavoured syrup, and the flour product for later use;

(R2): heating the cooking oil and then adding the cooking oil to the flour product; and

(R3): heating the flavoured syrup, followed by mixing the flavoured syrup with the flour product processed in the step (R2) to coat surfaces of the flour product with the flavoured syrup, so as to obtain the cold-processed pastry.

In the step (R2), the cooking oil was heated to 50°C.

The cooking oil was added in an amount that was 91% of the weight of the flour product of the step (Rl).

In the step (R3), the flavoured syrup was heated to 70°C; and the flavoured syrup was mixed with the flour product processed in the step (R2) at a weight ratio of 7.6: 10.

Comparative Example 1

This comparative example differs from Embodiment 1 in that the step (SI) does not involve the process of resting. Comparative Example 2

This comparative example differs from Embodiment 1 in that, the step (S2) employed frying in place of microwaving; in the frying, a noodle was fried in palm oil at a frying temperature of 160°C. In the frying process, color changes and oil-bath bubbles were observed, and the noodle was taken out in time so as to obtain a flour product.

Comparative Example 3

This comparative example differs from Embodiment 1 in that the dough was prepared by mixing 430 parts by weight of flour and 80 parts by weight of water.

Embodiment 8 Performance Test

I. Flour products prepared in Embodiments 1 to 4 and Comparative Examples 1 to 3 were acquired and tested for the moisture, volume puffing factors, total count of bacterial colony, and coliform group thereof, and observed for expansion effects thereof The total count of bacterial colony was determined according to total count of microorganism colony of food in GB 4789.2-2016, the coliform group was determined according to the plate count method in GB 4789.3-2016, and standard ranges of the total count of bacterial colony and the coliform group were based on the stipulations of hygienic standards of pastries and bread in GB 7099-20155. Test results are as shown in Table 1 :

Table 1

invention all achieved puffing effects. However, in Comparative Example 1, the puffed volume was merely 1.5 times the original volume; the flour product could not adequately expand, and no significant puffing effects could be achieved. In Comparative Example 2, the puffed volume was less than those in Embodiments 1 to 4. With consideration that the dough ingredients used in the present invention are suitable for the microwave puffing according to the present invention, frying provides slightly poorer effects. In Comparative Example 3, no significant change was found, indicating that the present invention needs to employ particular ingredients and parts according to the present invention to thereby obtain an effect of puffing until the volume thereof becomes several times of the original volume, and that puffing cannot be achieved if the dough is prepared only with flour and water.

II. Cold-processed pastries prepared in Embodiments 1 to 4 and Comparative Examples 1 to 2 were acquired and tested for the moisture, heavy metal lead content, fat content, acid value and peroxide value thereof, where standard ranges of the acid value and the peroxide value were based on stipulations of hygienic standards of pastries and bread in GB 7099-20155. Test results are as shown in Table 2:

Table 2

It can be seen from Table 2 above that, the cold-processed pastries prepared in the present invention had water contents between 9.5% and 1 1.0%. Fat contents were only between 18.0% and 19.5%, which are much lower than cold-processed pastries prepared by using fried flour products. Thus, the cold-processed pastries prepared in the present inventionare are more beneficial to consumer health. In Comparative Example 2, the peroxide value is on the higher side and is considered to be caused by oil reaction in the frying process.

It can be seen from FIGs. 1 to 12 that the volume after puffing of the flour product prepared through the preparation method of a flour product according to the present invention changed significantly as compared with the volume before puffing. With the strip flour product in the middle of FIG. 4 as an example, the ratio of the area of the dough before puffing to that of the flour product after puffing was about 8:48 (namely, 1 :6), and the puffing effect was significant.

III. Based on the technical solution of preparing flour products in Embidoment 1, six experimental groups were set up to observe the puffing effects, taking“the duration of the resting in the step (SI)” as a variable. The resting time employed in the 6 experimental groups were respectively 30 min, 60 min, 90 min, 120 min, 150 min and 180 min, and the flour products prepared were as shown in FIG. 13. It can be seen from FIG. 13 that the flour products with the resting time of 30 min or 60 min did not show significant puffing, and there was no significant light and porous structure; nonuniform expansion was found in the flour products. The flour products with the resting time of 90 min, 120 min, 150 min or 180 min had significant puffing; light and porous structures with uniform expansion of the flour products could be found. Within the range from 90 to 180 min, the longer the resting time was, the better the puffing effect.

Embodiment 9

The procedure of Embodiment 1 was followed with and without additional hot gas being blown over the flour product. The air was at a temperature of 135°C and a maximum speed of 18000 m ³ /h. The use of the hot air in combination with the microwave was found to increase the puffing ratio of the flour product.

The above embodiments are preferred solutions to implement the present invention. In addition to these embodiments, the present invention can also be implemented in other ways. Without departing from the design of the present invention, any obvious replacement falls within the protection scope of the present invention.