Formula and preparation method of porous noodle product

Abstract

The invention relates to the technical field of flour food, in particular to a formula and a making method of a porous noodle product. Specifically, the invention provides the method for improving the porosity of the hollow fine dried noodles, and the method comprises the following steps: rolling a dough containing pregelatinized starch to obtain a dough sheet with the thickness of less than or equal to 1.0 mm, cutting the dough sheet into strips to obtain noodles with the width of more than two times of the thickness of the dough sheet, and preparing the hollow fine dried noodles, wherein the gelatinization degree of the pregelatinized starch is at least 30%; the content of the pregelatinized starch in the dough is at least 3wt% based on the total weight of the dry powder or the dry material required for preparing the dough. The fermented hollow fine dried noodles disclosed by the invention are attractive in appearance and high in porosity, and the cooking time is shortened.

Description

Technical Field

[0001] The present invention relates to the technical field of flour-based foods, and particularly relates to a formula and a manufacturing method for porous (hollow) noodle products. Background Art

[0002] In the market, there is a non-extruded hollow noodle product, "fermented hollow dried noodles". By adding active yeast, fermentation metabolism occurs in the noodles during the noodle drying process to generate air holes. At the same time, the drying surface hardening is used to stabilize the outer structure of the dried noodles, maintain the smoothness of the outer surface, and enclose the internal air cavities. For example, CN109984294A discloses that the porosity range of the cross-section of fermented noodles is between 5% and 30%, with 30% being the optimal upper limit. Zhang Yunhua et al. studied the effects of different yeasts and addition amounts on the expansion index of fermented dried noodles. However, when the current fermented hollow dried noodles become thinner in thickness or narrower in width, the hollow structure will completely disappear, and there will be no corresponding unique appearance.

[0003] There are two types of examples where the pore size is visually insufficient or non-existent:

[0004] a) The noodle rolling is too thin, resulting in too fast a water evaporation rate, where the plastic deformation resistance of the noodles is greater than the positive air pressure generated by the yeast (such as Figure 1 );

[0005] b) The noodles are thick enough to retain moisture, but due to the uniform geometry, the air pressure distribution is uniform, and the yeast air holes are very small or microscopically visible (such as Figure 2 ).

[0006] Therefore, there is an urgent need in the art for a fermented hollow dried noodle. When the noodles start to dry, a limited degree of internal structural stress fracture of the noodles is required to generate large pores visible to the naked eye, and the cross-section of the noodles needs to be rectangular to promote non-uniform gas pressure distribution. Summary of the Invention

[0007] The purpose of the present invention is to produce a porous hollow noodle product with a relatively thin strip shape and a relatively thin thickness.

[0008] The first aspect of the present invention provides a method for increasing the porosity of hollow dried noodles. The method includes the steps of rolling a dough containing pregelatinized starch to obtain a sheet with a thickness ≤ 1.0 mm, cutting the sheet into noodles with a width more than twice the thickness of the sheet, and fermenting to prepare hollow dried noodles; wherein: the gelatinization degree of the pregelatinized starch is at least 30%; based on the total weight of the dry powder or dry materials required for preparing the dough, the content of pregelatinized starch in the dough is at least 3 wt%.

[0009] In one or more embodiments, the cross-section of the noodles is rectangular.

[0010] In one or more embodiments, the gelatinization degree of the pregelatinized starch is at least 50%, preferably at least 70%.

[0011] In one or more embodiments, based on the total weight of the dry powder or dry materials required for preparing the dough, the content of the pregelatinized starch in the dough is at least 5 wt%, preferably at least 10 wt%, such as 3 - 5 wt% or 5 - 10 wt%.

[0012] In one or more embodiments, the width of the noodles obtained by cutting the noodle sheets is ≥ 1.5 mm.

[0013] In one or more embodiments, the pregelatinized starch is mixed with flour and then water is added to knead the dough; alternatively, the pregelatinized starch is added to water, stirred evenly and then mixed with flour to knead the dough; alternatively, the pregelatinized starch is added to a mixture containing flour and water to knead the dough.

[0014] In one or more embodiments, the method further includes a step of preparing the pregelatinized starch. Preferably, the pregelatinized starch is prepared by heating in a water bath.

[0015] In one or more embodiments, heating in a water bath at 60 - 65 °C for 10 - 20 min gives pregelatinized starch with a gelatinization degree of 25 - 30%.

[0016] In one or more embodiments, heating in a water bath at 65 - 70 °C for 10 - 20 min gives pregelatinized starch with a gelatinization degree of 30 - 35%.

[0017] In one or more embodiments, heating in a water bath at 70 - 75 °C for 10 - 20 min gives pregelatinized starch with a gelatinization degree of 65 - 70%.

[0018] In one or more embodiments, heating in a water bath at 90 - 95 °C for 10 - 20 min gives pregelatinized starch with a gelatinization degree of 95 - 100%.

[0019] In one or more embodiments, the dough for preparing the hollow dried noodles further contains flour, starch, yeast, water and optional auxiliary materials and / or additives.

[0020] In one or more embodiments, the flour is selected from one or more of low - gluten flour, medium - gluten flour and high - gluten flour.

[0021] In one or more embodiments, the starch is selected from one or more of tuber starches, legume starches, and cereal starches; preferably, the tuber starch is selected from one or more of sweet potato starch, potato starch, cassava starch, and batata starch; preferably, the legume starch is selected from mung bean starch, pea starch, and combinations thereof; preferably, the cereal starch is selected from wheat starch, corn starch, and combinations thereof; preferably, the starch is potato starch, cassava starch, or a mixture of potato starch and cassava starch.

[0022] In one or more embodiments, the excipients include salt and / or vital gluten.

[0023] In one or more embodiments, the additives are selected from one or more of flour treatment agents, stabilizers, and emulsifiers; preferably, the flour treatment agent is L-cysteine hydrochloride; preferably, the stabilizer or emulsifier is sodium stearoyl lactylate and / or calcium stearoyl lactylate.

[0024] In one or more embodiments, based on the total weight of the dry powder or dry materials required for preparing the dough, the content of salt may be 0.01 - 2 wt% or 0.7 - 1.5 wt%.

[0025] In one or more embodiments, based on the total weight of the dry powder or dry materials required for preparing the dough, the content of vital gluten may be 1.5 - 2.5 wt% or 1 - 2 wt%.

[0026] In one or more embodiments, based on the total weight of the dry powder or dry materials required for preparing the dough, the content of yeast is 0.5 - 2 wt%, preferably 1.5 - 2 wt%.

[0027] In one or more embodiments, based on the total weight of the dry powder or dry materials required for preparing the dough, the content of the additives is 0.01 - 0.5 wt%, preferably 0.01 - 0.2 wt% or 0.01 - 0.025 wt%.

[0028] The second aspect of the present invention provides hollow dried noodles prepared by the method according to any one of the embodiments herein.

[0029] The third aspect of the present invention provides a food product, which is obtained by freezing the hollow dried noodles according to any one of the embodiments herein.

[0030] In one or more embodiments, the food product is a quick-frozen flour product.

[0031] The fourth aspect of the present invention also provides the use of pregelatinized starch in increasing the porosity of fermented flour products; wherein, the dough for preparing the fermented flour products contains at least 3 wt% of pregelatinized starch, and the gelatinization degree of the pregelatinized starch is at least 30%, preferably at least 50% or at least 70%; based on the total weight of the dry powder or dry materials required for preparing the dough, the content of pregelatinized starch in the dough is at least 5 wt%, preferably at least 10 wt%, for example 3 - 5 wt% or 5 - 10 wt%.

[0032] In one or more embodiments, the fermented flour product is hollow hanging noodles.

[0033] In one or more embodiments, the cross-section of the noodles of the hollow hanging noodles before fermentation is rectangular.

[0034] In one or more embodiments, the thickness of the noodles of the hollow hanging noodles before fermentation is ≤ 1.0 mm.

[0035] In one or more embodiments, the ratio of the width to the length of the noodles of the hollow hanging noodles before fermentation is ≥ 2. In one or more embodiments, the width of the noodles of the hollow hanging noodles before fermentation is ≥ 1.5 mm. Description of the Drawings

[0036] Figure 1 It is a schematic diagram of the disappearance of the pore appearance caused by the excessive thinness of ordinary fermented hanging noodles.

[0037] Figure 2 It is a schematic diagram of the disappearance of the pore appearance caused by the excessive uniformity of the thickness of ordinary fermented hanging noodles.

[0038] Figure 3 It is the influence result of the starch gelatinization degree on the porosity of fermented hanging noodles. Among them, from left to right are Comparative Example 1, Comparative Example 2, Example 1, Example 2 and Example 3.

[0039] Figure 4 It is the influence result of the addition amount of pregelatinized starch on the porosity and cooking time of fermented hanging noodles. Among them, the upper part of the picture is the first row, and the lower part of the picture is the second row; from left to right in the first row are Comparative Example 3, Comparative Example 4, Comparative Example 5, and from left to right in the second row are Example 4, Example 5, Example 6.

[0040] Figure 5 It is the influence result of the diameter ratio of fermented noodles on the porosity. Among them, the upper part of the picture is the first row, and the lower part of the picture is the second row; from left to right in the first row are Comparative Example 6, Comparative Example 7, Example 7, and from left to right in the second row are Comparative Example 8, Comparative Example 9.

[0041] Figure 6The results of the influence of different noodle strip shapes on the appearance of noodles are shown. Among them, the upper part of the picture is the first row, and the lower part of the picture is the second row; from left to right in the first row are Comparative Example 10 and Comparative Example 11, and from left to right in the second row are Example 5 and Example 7.

[0042] Figure 7 They are different noodle pressing knife types. Figure 7 (A) is a round knife tooth roller noodle pressing knife (round knife type), Figure 7 (B) is a flat knife tooth roller noodle pressing knife (flat knife type). Detailed implementation manners

[0043] To enable those skilled in the art to understand the features and effects of the present invention, the following is a general description and definition of the terms and phrases mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meanings understood by those skilled in the art for the present invention. When there are conflicts, the definitions in this specification shall prevail.

[0044] The theories or mechanisms described and disclosed herein, whether correct or incorrect, shall not limit the scope of the present invention in any way, that is, the content of the present invention can be implemented without being limited by any specific theory or mechanism.

[0045] In this article, terms such as "comprising", "including", "containing" and similar terms cover the meanings of "consisting essentially of" and "consisting of". For example, when this article discloses "A comprises B and C", it should be considered that "A consists essentially of B and C" and "A consists of B and C" have been disclosed herein.

[0046] In this article, all features defined in the form of numerical ranges or percentage ranges, such as numerical values, quantities, contents and concentrations, are only for the sake of simplicity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be regarded as having covered and specifically disclosed all possible sub-ranges and individual numerical values within the range (including integers and fractions).

[0047] In this article, unless otherwise specified, the percentage refers to the mass percentage, and the ratio refers to the mass ratio.

[0048] In this article, the sum of the percentage contents of the components of the composition is 100%.

[0049] In this article, the porosity is measured according to the ratio of the volume difference before and after the fermentation of the hanging noodles to the volume of the fermented hanging noodles.

[0050] In this article, pre-gelatinization is a process in which starch granules swell and split in water at an appropriate temperature (generally 60 - 80 °C) to form a uniform paste solution. Its essence is that the hydrogen bonds between starch molecules are broken and dispersed in water to become a colloidal solution.

[0051] In this text, the gelatinization degree has the commonly used definition in the art and is an index for measuring the cooking degree of grains or foods, which is derived from the morphological change of starch. In this text, a differential scanning calorimeter (DSC) is used to detect the gelatinization degree, and the gelatinization degree of unheated starch is 0%.

[0052] In this text, when describing the embodiments or examples, it should be understood that they are not used to limit the present invention to these embodiments or examples. On the contrary, all alternatives, modifications, and equivalents of the methods and materials described in the present invention can be covered within the scope defined by the claims.

[0053] In this text, for the sake of brevity of description, not all possible combinations of all technical features in each embodiment or example are described. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each embodiment or example can be combined arbitrarily, and all possible combinations should be considered to be within the scope described in this specification.

[0054] The inventors found that the porosity of thin hollow dried noodles with a thickness of less than 1 mm will decrease or even the pores will disappear, and porous hollow dried noodles cannot be obtained. However, using pregelatinized starch with a certain gelatinization degree to replace part of the flour and controlling the thickness of the noodle sheet, the width of the noodles, and the ratio between the two during the calendering and cutting process can increase its porosity. The thin hollow dried noodles prepared thereby not only have a beautiful appearance, but also their porous hollow structure can increase the water absorption area of the noodles and reduce the cooking time of the noodles. Thus, the present invention is completed.

[0055] Therefore, the present invention provides a method for the porosity of hollow dried noodles, or a method for preparing hollow dried noodles with increased porosity. The method includes the steps of calendering a dough containing pregelatinized starch to obtain a noodle sheet with a thickness ≤ 1.0 mm, cutting the noodle sheet into noodles with a width more than 2 times the thickness of the noodle sheet, and fermenting to prepare hollow dried noodles.

[0056] In one or more embodiments, the cross-section of the noodles is rectangular.

[0057] In this text, based on the total weight of the dry powder or dry materials required for preparing the dough, the content of pregelatinized starch in the dough is at least 3 wt%, preferably at least 5 wt% or 10 wt%, such as 3 - 5 wt% or 5 - 10 wt%.

[0058] In this text, the gelatinization degree of the pregelatinized starch is at least 30%, preferably at least 50%, at least 70%, such as 100%.

[0059] In some embodiments, the width of the noodles obtained by cutting the noodle sheet is ≥ 1.5 mm.

[0060] In some embodiments, the method of the present invention further includes the step of preparing pregelatinized starch.

[0061] Pregelatinization is a commonly used method in the art, such as water bath heating, steam gelatinization, and enzymatic gelatinization. Usually, starch can be heated in a water bath with water added to break the starch molecular chains, causing swelling and gelatinization to form colloidal gelatinized starch. The mixing ratio of starch and water can be selected according to the actual amount of pregelatinized starch required and the type of starch, such as (0.5 - 5):1 or (1 - 1.5):1. In an exemplary embodiment, pregelatinization is carried out by water bath heating, and pregelatinized starch is obtained after mixing wheat starch and water in equal volumes and heating in a water bath. It should be understood that the degree of pregelatinization is related to the time and temperature of the pregelatinization treatment and is selected according to actual needs. For the same water bath time, the higher the heating temperature, or for the same water bath temperature, the longer the water bath heating time, the higher the gelatinization degree of the starch. The water bath heating temperature is usually 60 - 99 °C, and the water bath heating time can be 10 - 60 min or 10 - 20 min. In some embodiments, pregelatinized starch with a gelatinization degree of 25 - 30% is obtained by heating in a water bath at 60 - 65 °C for 10 - 20 min. In some embodiments, pregelatinized starch with a gelatinization degree of 30 - 35% is obtained by heating in a water bath at 65 - 70 °C for 10 - 20 min. In some embodiments, pregelatinized starch with a gelatinization degree of 65 - 70% is obtained by heating in a water bath at 70 - 75 °C for 10 - 20 min. In some embodiments, pregelatinized starch with a gelatinization degree of 95 - 100% is obtained by heating in a water bath at 90 - 95 °C for 10 - 20 min.

[0062] Herein, the starch can be various edible starches known in the art, especially various starches conventionally used in the art for preparing noodles, including but not limited to one or more of tuber starches, legume starches, and cereal starches. The tuber starch can be one or more of sweet potato starch, potato starch, cassava starch, and sweet potato starch. The legume starch is selected from mung bean starch and / or pea starch, and the cereal starch can be wheat starch and / or corn starch. In some embodiments, the starch is selected from one or more of wheat starch, corn starch, cassava starch, sweet potato starch, or potato starch.

[0063] The complete method for preparing hollow dried noodles includes the steps of dough mixing, rolling, cutting, fermentation, and drying.

[0064] In the method of the present invention, when preparing the dough for hollow hanging noodles, there are no particular restrictions on the timing and manner of adding the pregelatinized starch. For example, the pregelatinized starch can be mixed with flour and then water is added to knead the dough. Or, the pregelatinized starch can be added to water, stirred evenly and then mixed with flour to knead the dough. Or, the pregelatinized starch can be added to a mixture containing flour and water to knead the dough. Conventional methods can be used for kneading the dough, and the obtained dough can be prepared into corresponding noodle products. In the kneading step, flavoring agents or auxiliary materials can be first added to water, and then the remaining raw materials such as flour are added and stirred into evenly granulated noodle flocs. In the rolling step, the noodle sheet can be gradually thinned and the gluten extended from the wide noodle roller spacing to the narrow noodle roller spacing in sequence. For example, the dough can be sheeted at a noodle roller spacing of 3.5 - 0.75 mm or 3.5 - 1.0 mm to make corresponding noodle sheets.

[0065] The methods of fermentation and drying can be those commonly used in the art, such as adopting a step of gradient temperature increase. The temperature, humidity and time of fermentation can be selected according to the size and water content of the dough. Generally, the fermentation temperature is 35 - 38 °C, the fermentation humidity is 70 - 80%, and the fermentation time is 1.5 - 3 h or 2 - 3 h. In an exemplary embodiment, the noodles are fermented at 30 - 38 °C or 33 - 38 °C and a humidity of 70 - 80% for 2 - 3 h, then dried at 40 - 45 °C and a humidity of 70 - 75% for 1.5 - 2 h, and finally dried at 30 - 35 °C and a humidity of 60 - 65% for 1.5 - 2 h to make hollow hanging noodles.

[0066] The fermented dough for preparing hollow hanging noodles usually contains flour, yeast, pregelatinized starch and water.

[0067] In this article, the flour can be flour from wheat sources and / or non - wheat sources commonly used in the art for preparing various noodle products, especially hanging noodles. Non - wheat source flours include, but are not limited to, cereal flours such as buckwheat flour, corn flour, potato flour, rice flour, glutinous rice flour, sorghum flour, rye flour, soybean flour, and vegetable flours such as pumpkin flour, spinach flour, carrot flour, broccoli flour, cauliflower flour, kale flour, purple sweet potato flour, tomato flour, onion flour, etc. Preferably, it is one or more of buckwheat flour and spinach flour. According to the protein content in the flour, the flour can be divided into low - gluten flour, medium - gluten flour and high - gluten flour. In this article, the flour includes one or more of low - gluten flour, medium - gluten flour and high - gluten flour. The low - gluten flour, medium - gluten flour and high - gluten flour have well - known meanings in the art. For example, the crude protein content of low - gluten flour is usually below 8.5%, the crude protein content of medium - gluten flour is usually 8.5 - 11.5%, and the crude protein content of high - gluten flour is above 11.5%.

[0068] In some embodiments, the flour also contains starch. The types of starch are as described herein, and the content of starch can be determined according to the properties of the dough or noodles as actually required. In some embodiments, based on the total weight of the dry powder or dry ingredients required for preparing the dough, the content of starch is 10-20 wt%, preferably 15-20 wt%.

[0069] The amounts of the components in the fermented dough vary depending on the flour, and those skilled in the art can determine them according to conventional technical means. For example, based on the total weight of the dry powder or dry ingredients required for preparing the dough, the amount of water is usually 25-35 wt%, preferably 30-35 wt% or 32-35 wt%, and the amount of yeast can be 0.5-2 wt%, preferably 1.5-2 wt%.

[0070] In the dough of the present invention, in addition to the dry powder (dry ingredients) such as flour, yeast and pregelatinized starch, and water, it may also contain common auxiliary materials and / or additives for noodle products.

[0071] For example, the auxiliary materials include salt and / or vital gluten. The addition amount of the auxiliary materials can be adjusted according to the types of fresh wet noodle products and actual requirements. In some embodiments, based on the total weight of the flour, the content of salt can be 0.01-2 wt% or 0.7-1.5 wt%. In some embodiments, based on the total weight of the flour, the content of vital gluten can be 1.5-2.5 wt% or 1-2 wt%.

[0072] The additives may include one or more components among flour treatment agents (L-cysteine hydrochloride), stabilizers, and emulsifiers (sodium stearoyl lactate, calcium stearoyl lactate).

[0073] In some embodiments, the present invention also provides a hollow hanging noodle, which is prepared by the method described in any one of the embodiments herein.

[0074] In some embodiments, the present invention also provides a food, which is a quick-frozen noodle product or a quick-frozen food prepared from the hollow hanging noodle described herein.

[0075] In some embodiments, the present invention also provides the use of pregelatinized starch in increasing the porosity of fermented flour products; wherein, the dough for preparing the fermented flour products contains at least 3 wt% of pregelatinized starch, and the gelatinization degree of the pregelatinized starch is at least 30%, preferably at least 50% or at least 70%; based on the total weight of the dry powder or dry materials required for preparing the dough, the content of pregelatinized starch in the dough is at least 5 wt%, preferably at least 10 wt%, such as 3 - 5 wt% or 5 - 10 wt%. Preferably, the fermented flour product is hollow hanging noodles; preferably, the cross-section of the noodles before fermentation of the hollow hanging noodles is rectangular; preferably, the thickness of the noodles before fermentation of the hollow hanging noodles is ≤ 1.0 mm; preferably, the ratio of the width to the length of the noodles before fermentation of the hollow hanging noodles is ≥ 2.

[0076] The present invention has the following beneficial effects:

[0077] The present invention uses a composition of flour, pregelatinized starch and active yeast to produce a thin strip-shaped fermented hollow hanging noodles. In the operating range where obvious pores cannot be formed by the existing fermented flour process (the noodles are made thinner and finer), the present invention can generate pores, and the porosity can reach 20 - 40%. The cross-section of the noodles before fermentation is rectangular, and the shape after fermentation is a hexagonal shape with sharp corners, including pores that are clearly visible to the naked eye. In addition to the beautiful appearance of the fermented hollow hanging noodles of the present invention, the cooking time is also reduced. Compared with the cooking time of ordinary fermented hollow hanging noodles, which is 7.5 - 8 minutes, the cooking time of the thin strip fermented hollow hanging noodles is 4.5 - 5 minutes.

[0078] The present invention will be further described below by way of specific examples. It should be understood that these examples are merely illustrative and not intended to limit the scope of the present invention. The methods and reagents used in the examples are conventional methods and reagents in the art unless otherwise specified.

[0079] Instruments and equipment

[0080] Yeast: Purchased from Angel Yeast Co., Ltd. "Yanshan" low-sugar dry yeast, Yantai, Shandong;

[0081] Dough mixer: Hobart mixer, with a flaky mixing head, adjustable speed;

[0082] Noodle machine: JMTD 168 / 140 type test noodle machine, Beijing Oriental Fude, the roll gap is adjustable between 0.5 mm - 6.0 mm;

[0083] Intelligent hanging noodle drying system: China National Packaging and Food Machinery Corporation, fully automatic intelligent hanging noodle drying system, temperature and humidity controlled in sections;

[0084] Induction cooker: The minimum power is 1600 W.

[0085] Noodle porosity

[0086] The calculation of the noodle porosity refers to CN109984294A, and the porosity = (V0 - V1) / V0, where V0 is the volume of the porous dried noodle, and V1 is the volume of the non-fermented ordinary dried noodle.

[0087] Calculation of gelatinization degree

[0088] The gelatinization degree was detected using a differential scanning calorimeter (DSC). The detection method refers to W.-C. Wang, S.K. Sastry, Starch gelatinization in ohmic heating, Journal of Food Engineering, 34(3)(1997), pp. 225 - 242. The formula for calculating the gelatinization degree is as follows:

[0089] DSG(%) = (1 - △H 样品 / △H 原淀粉 )×100%

[0090] In the formula, DSG is the gelatinization degree; △H is the enthalpy value; the native starch is the starch of the same type as the starch sample to be measured without gelatinization, and its gelatinization degree is 0%.

[0091] Noodle making method

[0092] Dough kneading: Weigh 0.7 wt% of salt based on the mass of flour. First, dissolve the edible salt in water, then add the flour and salt water to the dough kneading tank in sequence to start kneading. Stir at speed 5 for 5 min and then at speed 7 for 5 min to form dough flakes with uniform particles and appropriate dryness and humidity. The temperature of the dough flakes is between 25°C ± 5°C.

[0093] Sheet rolling: Adjust the roller spacing between the two rollers to 3.5 mm, and perform a single rolling on the above-mentioned compounded sheet. Then perform rolling at roller spacings of 3 mm, 2.5 mm, 2 mm, and 1.5 mm in sequence to gradually thin the sheet and gradually extend the gluten to form a sheet with uniform thickness and smooth surface. Adjust the roller spacing between the two rollers of the noodle machine to 0.75 - 1.5 mm (corresponding to the noodle thickness in each example and comparative example), and perform the final rolling of the sheet at this roller spacing. Then slowly feed the sheet into a flat knife tooth roller noodle cutter with a width of 1 - 3 mm (corresponding to the noodle width in each example and comparative example) to cut the noodles with a consistent width.

[0094] Fermentation and drying: Dry the noodles to obtain dried noodles. The fermentation and drying procedures are shown in the following table:

[0095] Table 1: Dried noodle drying procedure

[0096] Step Time min Temperature °C Humidity % 1 120 33 75 2 60 38 75 3 120 40 72 4 60 35 60

[0097] Preparation Example 1

[0098] Mix wheat starch and water in an equal volume ratio of 1:1, heat in a water bath at 64 °C for 15 minutes, then freeze-dry and pulverize, and conduct DSC gelatinization degree detection to obtain pregelatinized starch with a gelatinization degree of 25.1%.

[0099] Preparation Example 2

[0100] Mix wheat starch and water in an equal volume ratio of 1:1, heat in a water bath at 68 °C for 15 minutes, then freeze-dry and pulverize, and conduct DSC gelatinization degree detection to obtain pregelatinized starch with a gelatinization degree of 30.4%.

[0101] Preparation Example 3

[0102] Mix wheat starch and water in an equal volume ratio of 1:1, heat in a water bath at 72 °C for 15 minutes, then freeze-dry and pulverize, and conduct DSC gelatinization degree detection to obtain pregelatinized starch with a gelatinization degree of 68.4%.

[0103] Preparation Example 4

[0104] Mix wheat starch and water in an equal volume ratio of 1:1, heat in a water bath at 90 °C for 15 minutes, then freeze-dry and pulverize, and conduct DSC gelatinization degree detection to obtain pregelatinized starch with a gelatinization degree of 100%.

[0105] (I) Influence of starch gelatinization degree on the porosity of the fermentation hanging surface

[0106] Comparative Example 1

[0107] Prepare dough according to the following formula: The dry materials are medium gluten flour (11.0% protein), unheated starch (gelatinization degree of 0%), and yeast. Based on the total weight of the dry materials, the flour is 93.5 wt%, the unheated starch is 5 wt%, the yeast is 1.5 wt%, and the water is 32 wt%.

[0108] Comparative Example 2

[0109] Prepare dough according to the following formula: The dry materials are medium gluten flour (11.0% protein), the pregelatinized starch in Preparation Example 1, and yeast. Based on the total weight of the dry materials, the flour is 93.5 wt%, the pregelatinized starch is 5 wt%, the yeast is 1.5 wt%, and the water is 32 wt%.

[0110] Example 1

[0111] Prepare dough according to the following formula: The dry materials are medium gluten flour (11.0% protein), the pregelatinized starch in Preparation Example 2, and yeast. Based on the total weight of the dry materials, the flour is 93.5 wt%, the pregelatinized starch is 5 wt%, the yeast is 1.5 wt%, and the water is 32 wt%.

[0112] Example 2

[0113] Prepare the dough according to the following formula: The dry ingredients are medium gluten flour (11.0% protein), the pregelatinized starch in Preparation Example 3, and yeast. Based on the total weight of the dry ingredients, the flour is 93.5 wt%, the pregelatinized starch is 5 wt%, the yeast is 1.5 wt%, and the water is 32 wt%.

[0114] Example 3

[0115] Prepare the dough according to the following formula: The dry ingredients are medium gluten flour (11.0% protein), the pregelatinized starch in Preparation Example 4, and yeast. Based on the total weight of the dry ingredients, the flour is 93.5 wt%, the pregelatinized starch is 5 wt%, the yeast is 1.5 wt%, and the water is 32 wt%.

[0116] Detect the dough in the above-mentioned examples and comparative examples by rolling and cutting the strips with a flat knife tooth roller with a size of 2×1 mm( Figure 7 (B)), and ferment and dry to obtain hollow noodles. The porosity results are shown in the following table, and the cross-sectional appearance of the noodles is as Figure 3 shown.

[0117] Table 2: Pasting degree and porosity after fermentation of noodles

[0118] Add 5 wt% pregelatinized starch Gelatinization degree (%) Porosity (%) Comparative Example 1 0 0 Comparative Example 2 25.1 21.4 Example 1 30.4 30.7 Example 2 68.4 36.3 Example 3 100 35.5

[0119] The results show that when the addition amount of pregelatinized starch is 5 wt%, the pregelatinized starch with a pasting degree above 30% can enhance the porosity of the fermented dough, and the pregelatinized starch with a pasting degree of 68-100% has the best effect.

[0120] (II) Influence of the addition amount of pregelatinized starch on fermented noodles

[0121] Prepare the noodles of Examples 4-6, Comparative Example 3-5 and Comparative Example 12-13 according to the noodle formula and the size of the noodle rolling knife shown in the following table. Among them, the pregelatinized starch is the pregelatinized starch with a pasting degree of 100% in Preparation Example 4, and the remaining formula, dough mixing, rolling, fermentation and drying procedures are the same as those in “(I) Influence of starch pasting degree on the porosity of fermented noodles”.

[0122] Detect the porosity and cooking time of the noodles after rolling, cutting and fermenting the dough in the above-mentioned examples and comparative examples. The results are shown in the following table, and the cross-sectional appearance of the noodles is as Figure 4 shown.

[0123] Table 3: Noodle ingredients, porosity after fermentation, cooking time

[0124]

[0125]

[0126] *Note: The data of the cut noodles in the table are the width and thickness of the cross-section of the fermented noodles. For example, "Cut noodles: 3×1mm" means that the width of the cross-section of the noodles is 3mm and the thickness is 1mm, that is, the width of the noodles is 3mm and the thickness is 1mm.

[0127] The results show that when making thick noodles (thickness greater than 1mm, Comparative Examples 12, 13 and 3), due to the action of yeast, hollow hanging noodles with a relatively high porosity can be obtained regardless of whether the dough contains pregelatinized starch. When making thinner fermented noodles (noodle thickness ≤ 1mm), even if yeast is contained, the pores in the dough will disappear and hollow hanging noodles cannot be obtained (Comparative Example 4); while adding pregelatinized starch to the fermented dough can not only increase the porosity of the thin noodles, but also the higher the addition amount, the higher the porosity of the thin noodles (Comparative Example 5, Examples 4-6). In addition, the results also show that the steaming time of the noodles is not directly proportional to the porosity and the addition amount of pregelatinized starch (Comparative Example 5, Examples 4 and 6 are all 4.5mm, Comparative Examples 13 and 3 are all 7.5mm), and the thickness of the noodles may have a greater impact on the steaming time of the noodles (thick noodles ≥ 7.5min, thin noodles ≤ 5.5min).

[0128] (III) Effective limit of the noodle knife type diameter

[0129] Adjust the width: thickness diameter ratio of the fermented noodles downward from 3:1. Prepare the hanging noodles of Examples 7 and Comparative Examples 6-9 according to the noodle press knife types and sizes shown in the following table, and compare them with Examples 3 and 5. Among them, the pregelatinized starch is the pregelatinized starch with a gelatinization degree of 100% in Preparation Example 4, and the rest of the formula, dough mixing, calendering, fermentation and drying procedures are the same as those in "(I) Influence of starch gelatinization degree on the porosity of fermented hanging noodles".

[0130] Detect the porosity of the hollow hanging noodles prepared in the above examples and comparative examples. The results are as follows in the table, and the appearance of the noodle cross-section is as Figure 5 shown.

[0131] Table 4: Influence of noodle diameter ratio on porosity

[0132]

[0133]

[0134] The results show that the hollow hanging noodles prepared with a noodle cutter type having a width ≥ 1.5 mm and a thickness ≤ 1.0 mm have a higher porosity (Examples 3, 5, and 7). Further, the width-to-thickness ratio of the noodle strip prone to generating pores is 2:1. When the width-to-thickness ratio of the noodle cutter type ≥ 2:1, the increase in width has no negative impact on the porosity (Examples 3 and 5); when the width-to-thickness ratio of the noodle cutter type < 2:1, the porosity of the hollow hanging noodles will decrease (Comparative Examples 6 - 9).

[0135] (IV) Influence of Noodle Shape on Fermentation Appearance

[0136] Prepare the hanging noodles of Comparative Examples 10 - 11 and Example 3 according to the noodle cutter types shown in the following table. Among them, the pregelatinized starch is the pregelatinized starch with a gelatinization degree of 100% in Preparation Example 4, and the remaining formulations, noodle making, rolling, fermentation, and drying procedures are the same as those in "(I) Influence of Starch Gelatinization Degree on the Porosity of Fermented Hanging Noodles".

[0137] Detect the porosity of the hollow hanging noodles prepared in the comparative examples and compare them with those of Example 3, Example 5, and Example 7. The results are shown in the following table, and the cross-sectional appearance of the noodles is as Figure 6 shown.

[0138] Table 5: Influence of Different Shapes on the Appearance of Air Pores

[0139] Noodle shape before drying Strip shape Porosity (%) Comparative Example 10 1.5×1.5 mm round knife Round 3 Comparative Example 11 1.5×1.5 mm flat knife Square 5 Comparative Example 12 1.8x1 mm round knife Oval 12 Example 5 3×1 mm flat knife Rectangular 35 Example 7 1.5×0.75 mm flat knife Rectangular 24 Example 3 2×1 mm flat knife Rectangular 35.5

[0140] Combining the above table and the results of (III), before fermentation and drying, the noodles with a rectangular shape having a width-to-thickness ratio ≥ 2, that is, the noodle cutter type is a flat knife, have a higher porosity. The inventor speculates that part of the mechanism for forming large visible air pores includes stress fracturing, and the elliptical noodle strips will expand to a nearly 1:1 circle after fermentation. The circular shape will increase the structural integrity, uniform air pressure distribution, and reduce stress fracture. Therefore, the porosity of the fermented holes of circular or elliptical noodle strips is less than 20%, only micro pores, which are not obvious sensually.

Claims

1. A method for increasing the porosity of a hollow hanging hole, characterized in that, The method includes the steps of rolling a dough containing pregelatinized starch to obtain a sheet with a thickness ≤ 1.0 mm, cutting the sheet into strips to obtain noodles with a width more than twice the thickness of the sheet, and fermenting to prepare hollow dried noodles; wherein: The gelatinization degree of the pregelatinized starch is at least 30%; Based on the total weight of the dry powder or dry materials required for preparing the dough, the content of pregelatinized starch in the dough is at least 3 wt%.

2. The method according to claim 1, wherein: The gelatinization degree of the pregelatinized starch is at least 50%, preferably at least 70%; and / or Based on the total weight of the dry powder or dry materials required for preparing the dough, the content of pregelatinized starch in the dough is at least 5 wt%, preferably at least 10 wt%, such as 3 - 5 wt% or 5 - 10 wt%.

3. The method according to claim 1 or 2, characterized in that, The width of the noodles obtained by cutting the sheet is ≥ 1.5 mm.

4. The method according to any one of claims 1 to 3, characterized in that Mix the pregelatinized starch with flour and then add water to knead the dough; or, add the pregelatinized starch to water, stir evenly and then mix with flour to knead the dough; or, add the pregelatinized starch to a mixture containing flour and water and knead the dough.

5. The method according to any one of claims 1 - 4, the method further includes the step of preparing pregelatinized starch, preferably, preparing the pregelatinized starch by water bath heating; Preferably, heat in a water bath at 60 - 65 °C for 10 - 20 min to obtain pregelatinized starch with a gelatinization degree of 25 - 30%; Preferably, heat in a water bath at 65 - 70 °C for 10 - 20 min to obtain pregelatinized starch with a gelatinization degree of 30 - 35%; Preferably, heat in a water bath at 70 - 75 °C for 10 - 20 min to obtain pregelatinized starch with a gelatinization degree of 65 - 70%; Preferably, heat in a water bath at 90 - 95 °C for 10 - 20 min to obtain pregelatinized starch with a gelatinization degree of 95 - 100%.

6. The method according to any one of claims 1-5, characterized in that, The dough for preparing the hollow dried noodles further contains flour, starch, yeast, water and optional auxiliary materials and / or additives; Preferably, the flour is selected from one or more of low - gluten flour, medium - gluten flour and high - gluten flour; Preferably, the starch is selected from one or more of: potato starch, bean starch and cereal starch; preferably, the potato starch is selected from one or more of sweet potato starch, potato starch, tapioca starch and sweet potato starch; preferably, the bean starch is selected from mung bean starch, pea starch and their combination; preferably, the cereal starch is selected from wheat starch, corn starch and their combination; preferably, the starch is potato starch, tapioca starch, or a mixture of potato starch and tapioca starch; Preferably, the auxiliary materials include salt and / or vital gluten; Preferably, the additives are selected from one or more of flour treatment agents, stabilizers, emulsifiers; preferably, the flour treatment agent is L - cysteine hydrochloride; preferably, the stabilizer or emulsifier is sodium stearoyl lactate and / or calcium stearoyl lactate.

7. The method according to claim 6, wherein The dough for preparing the hollow dried noodles has one or more of the following characteristics: Based on the total weight of the dry powder or dry materials required for preparing the dough, the content of salt can be 0.01 - 2 wt% or 0.7 - 1.5 wt%; Based on the total weight of the dry powder or dry ingredients required for preparing the dough, the content of gluten can be 1.5 - 2.5 wt% or 1 - 2 wt%; Based on the total weight of the dry powder or dry ingredients required for preparing the dough, the content of yeast is 0.5 - 2 wt%, preferably 1.5 - 2 wt%; and Based on the total weight of the dry powder or dry ingredients required for preparing the dough, the content of the additive is 0.01 - 0.5 wt%, preferably 0.01 - 0.2 wt% or 0.01 - 0.025 wt%.

8. The hollow dried noodles prepared by the method according to any one of claims 1 - 7.

9. A food product, which is obtained by freezing the hollow dried noodles according to claim 8; preferably, the food product is a quick-frozen flour product.

10. Use of pregelatinized starch in increasing the porosity of fermented flour products; wherein, The dough for preparing the fermented flour product contains at least 3 wt% of pregelatinized starch, and the degree of gelatinization of the pregelatinized starch is at least 30%, preferably at least 50% or at least 70%; based on the total weight of the dry powder or dry ingredients required for preparing the dough, the content of pregelatinized starch in the dough is at least 5 wt%, preferably at least 10 wt%, such as 3 - 5 wt% or 5 - 10 wt%; Preferably, the fermented flour product is hollow dried noodles; Preferably, the cross-section of the noodles of the hollow dried noodles before fermentation is rectangular; Preferably, the thickness of the noodles of the hollow dried noodles before fermentation is ≤ 1.0 mm; Preferably, the ratio of the width to the length of the noodles of the hollow dried noodles before fermentation is ≥ 2; Preferably, the width of the noodles of the hollow dried noodles before fermentation is ≥ 1.5 mm.

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