Method for producing frozen noodles

Abstract

To provide frozen noodles causing little evaporation of water from the noodles after boiled while improving the production efficiency of the frozen noodles, having firm texture to such an extent that the core does not remain when eaten, and having smooth texture on the surface.SOLUTION: It has been found that when a lysyl oxidase derived from an eggshell membrane is used, noodles having no remaining core and having firm texture are obtained even after a short boiling time, the noodles hardly spread even after a prolonged boiling time, and the surface of the noodles after washing with water is smooth without unevenness and excellent in slipperiness.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for shortening the boiling time of frozen noodles and a method for improving the texture and physical properties of frozen noodles. [Background technology]

[0002] Frozen noodles are made by boiling fresh or dried noodles and then freezing them. The processing steps from boiling to freezing not only affect flavor and texture, but are also important for increasing production efficiency. If freshly boiled noodles are immediately placed in a freezer, the temperature inside the freezer rises, putting a heavy load on the freezer. Furthermore, the noodles are maintained at a high temperature for a while inside the freezer, which promotes evaporation of water from the surface of the noodles, gradually drying them out and causing the noodles to stick together, making them difficult to separate. For this reason, the manufacturing process generally involves rinsing the noodles with water after boiling and lowering the temperature of the boiled noodles before placing them in the freezer. However, frozen noodles that have been washed and cooled in this way lose the unique flavor of fresh noodles because the components on the surface of the noodles are washed away. Furthermore, the rapid cooling causes the noodles to become firm, resulting in a texture that is different from that of noodles immediately after boiling.

[0003] In response to these issues, Patent Document 1 discloses a method for producing frozen noodles in which fresh or dried noodles are boiled so that the water content is lower than that of boiled noodles obtained by conventional methods, water is applied to the surface of the boiled noodles, and the noodles are packed into a freezing container together with ice blocks. This production method solves the problems of shortening the boiling time, suppressing water evaporation from the surface of the noodles after boiling, reducing the load on the freezing machine, suppressing adhesion of noodles to each other, and maintaining flavor and texture. However, frozen noodles produced by this technology require a configuration that includes ice blocks and a freezing container, which places strict restrictions on the sales and distribution formats.

[0004] On the other hand, a desirable texture for noodles in general, not just frozen noodles, is one that has a moderate firmness when eaten, does not leave a core, and has a smooth surface. Although there is a lot of knowledge about how to strengthen the firmness in particular, it has been difficult to achieve a balanced improvement in quality, as problems such as the core remaining in the mouth, the loss of flexibility of the noodles making them brittle, or the occurrence of unevenness, roughness, or dullness on the surface of the noodles have occurred.

[0005] In this context, Patent Document 2 discloses that adding α-amylase and transglutaminase to cooked noodles improves the noodle's loosening properties, hardness, flexibility, and surface smoothness. Furthermore, Patent Document 3 discloses that adding lysyl oxidase to fresh udon noodles improves the firmness and smooth texture. Both the transglutaminase in Patent Document 2 and the lysyl oxidase in Patent Document 3 are enzymes that form cross-linked structures in proteins, and the former has been put to practical use as a food additive. However, when applying these findings to frozen noodles, the noodles become firmer but are more likely to retain their core, which requires extending the boiling time, making it difficult to improve production efficiency. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2023-019315 [Patent Document 2] Patent Publication No. 2021-129523 [Patent Document 3] JP 2-245145 [Patent Document 4] Patent Publication No. 4-094670 [Patent Document 5] International Publication No. 2003-056016 [Patent Document 6] International Publication No. 2008-113799 Summary of the Invention [Problem to be solved by the invention]

[0007] The problem to be solved by the present invention is to provide frozen noodles that are firm enough that no core remains when eaten and have a smooth surface texture, while increasing the production efficiency of frozen noodles. [Means for solving the problem]

[0008] In order to solve the above problems, the inventors added a certain amount of lysyl oxidase to the raw materials for frozen noodles and found that this increased the production efficiency of frozen noodles and resulted in good sensory evaluation.

[0009] That is, the present invention provides: (1) A method for producing quick-cooking frozen noodles, comprising adding 0.5 to 5.0 parts by weight of lysyl oxidase having a lysyl oxidase activity of 0.1 unit / g or more to 0.5 unit / g per 100 parts by weight of grain flour; (2) A method for producing quick-boiling frozen noodles, comprising adding 0.5 to 5.0 parts by weight of an eggshell membrane composition having a lysyl oxidase activity of 0.1 unit / g or more to 0.5 unit / g or more per 100 parts by weight of grain flour; (3) Quick-cooking frozen noodles containing lysyl oxidase or an eggshell membrane composition having lysyl oxidase activity, (4) The quick-cooking frozen noodles according to (3) above, in which the breaking stress ratio, expressed by the following formula, is 1.0 or more and less than 1.5 before freezing and 1.2 or more and less than 1.7 after re-boiling under the measurement conditions (a) to (c). (a) Measuring equipment: rheometer or texture analyzer (b) Plunger: wedge-shaped (c) Compression speed: 60 mm / min Breaking stress ratio (N1 / N2) = Breaking stress (N1) of frozen noodles obtained by the production method described in (1) or (2) above / Breaking stress (N2) of frozen noodles to which the lysyl oxidase described in (1) above or the eggshell membrane composition described in (2) above has not been added (5) The quick-cooking frozen noodles according to (3) above, in which the water absorption ratio, expressed by the following formula, is 0.85 or more and 0.95 or less before freezing and 0.81 or more and 0.86 or less after re-boiling. Water absorption ratio = Water absorption (%) of frozen noodles obtained by the manufacturing method described in (1) or (2) above / Water absorption (%) of frozen noodles to which the lysyl oxidase described in (1) above or the eggshell membrane composition described in (2) above has not been added (6) A method for shortening the boiling time of frozen noodles, comprising adding 0.5 to 5.0 parts by weight of a lysyl oxidase or eggshell membrane composition having a lysyl oxidase activity of 0.1 unit / g or more to 0.5 unit / g per 100 parts by weight of grain flour; (7) A method for suppressing boiled soggy noodles, comprising adding 0.5 to 5.0 parts by weight of a lysyl oxidase or eggshell membrane composition having a lysyl oxidase activity of 0.1 unit / g or more to 0.5 unit / g per 100 parts by weight of grain flour; This provides: [Effects of the Invention]

[0010] According to the present invention, an eggshell membrane composition prepared by drying and pulverizing eggshell membranes contains lysyl oxidase, and adding this eggshell membrane composition to frozen noodles makes it possible to produce noodles with a strong texture without a core even with a short boiling time, thereby improving production efficiency. Furthermore, frozen noodles to which this eggshell membrane composition has been added have a smooth, even surface after rinsing with water, with little water evaporation from the surface, and excellent slipperiness and loosening properties. Furthermore, frozen noodles to which lysyl oxidase has been added maintain excellent noodle firmness and slipperiness even with a long boiling time, are stable even with changes in boiling time, and are inhibited from becoming too soft when boiled. [Brief explanation of the drawings]

[0011] [Figure 1] Comparison of breaking stress [Figure 2] Comparison of microscope images of boiled noodle surfaces DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an embodiment of the present invention will be described.

[0013] The lysyl oxidase of the present invention is an enzyme also known as lysyl oxidase. Furthermore, the eggshell membrane composition of the present invention is a composition having lysyl oxidase activity, obtained from eggshell membrane. Eggshell membrane is a thin film found inside the eggshell, and is a fibrous insoluble protein containing elastin-like proteins and collagen. Eggshell membrane is produced in the thoracic region of the oviduct in the body of poultry such as chickens through cross-linking with lysyl oxidase. Eggshell membrane is composed of eggshell membrane fibers with a diameter of 1 to 4 μm. The eggshell membrane may be from any egg, such as chicken, quail, duck, ostrich, or pigeon, but chicken eggs are preferred due to their ease of availability.

[0014] The lysyl oxidase activity of the lysyl oxidase or eggshell membrane composition of the present invention is now described. Lysyl oxidase is a type of amine oxidase that oxidatively deaminates the ε-amino groups of lysine residues in proteins to generate aldehydes, resulting in crosslinking of proteins such as collagen and elastin. Lysyl oxidase is known to be immobilized on the eggshell membrane fibers that make up the eggshell membrane.

[0015] Eggshell membranes are obtained by peeling them off from eggshells after cracking. Preferably, the eggshell membranes are further washed to remove nutrients such as egg white and egg yolk. The eggshell membranes may be raw eggshell membranes (water content approximately 75%) peeled off from eggshells after cracking, or dried eggshell membranes obtained by drying raw eggshell membranes, but dried eggshell membranes are preferred. Dried eggshell membranes have a low water content and are less susceptible to microbial growth. Furthermore, the reduced volume and mass of the eggshell membranes make them more convenient to use.

[0016] Dried eggshell membranes can be produced by drying raw eggshell membranes. Raw eggshell membranes can be dried by known methods. Known drying methods include, for example, heat drying, low-temperature drying, vacuum drying, reduced-pressure drying, freeze drying, drum drying, fluidized-bed drying, and spray drying.

[0017] An eggshell membrane composition can be produced by pulverizing eggshell membranes. The method for pulverizing eggshell membranes is not particularly limited, and a planetary ball mill, cutter mill, hammer mill, jet mill, or the like can be used. However, to prevent microbial contamination of the eggshell membranes, it is preferable to use a closed-type pulverization method such as a planetary ball mill. The pulverization means and the container for containing the eggshell membranes are preferably made of plastic or coated with various coatings. The above-mentioned processing can prevent heat generation during pulverization due to frictional heat. To suppress heat generation during pulverization of eggshell membranes, the apparatus used for pulverization may further be equipped with a cooling mechanism. The method for pulverizing eggshell membranes is not particularly limited, and either dry pulverization, in which pulverization is performed in a dry state, or wet pulverization, in which pulverization is performed in a wet state with the addition of a liquid, can be used.

[0018] The lysyl oxidase derived from eggshell membranes or of other origins, or the eggshell membrane composition of the present invention, added to the quick-cooking frozen noodles of the present invention is preferably a lysyl oxidase or eggshell membrane composition that satisfies an activity value of preferably 0.1 to 35 units / g, more preferably 0.1 to 10 units / g, even more preferably 0.1 to 1 unit / g, and even more preferably 0.1 to 0.5 units / g, as measured by the plate assay method described below in paragraph 0019. If the activity is below 0.1 unit / g, it will be impossible to impart texture-improving effects such as firmness and smoothness to the frozen noodles, while if the activity exceeds 35 units / g, the activity value per volume and weight will be high, making fine adjustments for texture improvement impossible. Therefore, although it is possible to increase the firmness of the frozen noodles, if the boiling time is not extended, the core will tend to remain, the noodle strings will lose their suppleness, and the physical properties will become brittle, making this unsuitable for the production of quick-cooking frozen noodles. Lysyl oxidases other than those derived from eggshell membranes include those derived from calf thoracic aorta, as described in Patent Document 4, and those derived from microorganisms such as fungi and filamentous fungi, as described in Patent Documents 5 and 6. When using lysyl oxidases derived from these sources, it is sufficient that the activity value falls within the above-mentioned range.

[0019] Lysyl oxidase activity can be measured by any method, including, for example, a plate assay. The eggshell membrane composition is preliminarily solubilized as an eggshell membrane extract. The eggshell membrane extract is then reacted with n-butylamine, a substrate. The hydrogen peroxide generated in this reaction is then reacted with 4-aminoantipyrine and phenol in the presence of peroxidase. The absorbance at 500 nm of the resulting red quinone pigment is measured using a spectrophotometer, and the lysyl oxidase activity in the eggshell membrane extract is determined from this absorbance. A color-developing solution is prepared by adding 0.013 wt% 4-aminoantipyrine and 0.175 wt% phenol to potassium phosphate buffer (pH 7.0). To 890 μL of the color-developing solution, 10 μL of 1 M n-butylamine and 100 μL of 70 u / mL peroxidase are added, and purified water is added to this to make a total volume of 1 mL. This is the reaction solution. 200 μL of the reaction solution was added to 20 μL of the measurement sample obtained by each extraction method, and the mixture was placed in a thermomixer. The mixture was allowed to react at 37°C for 60 minutes, and the increase in absorbance at a wavelength of 500 nm was measured from 0 to 60 minutes. The lysyl oxidase activity value was calculated using the following formula: Activity u / mL(g)={(A5-A2)-(Ab5-Ab2)-(B5-B2)} / 3×3.1×1 / 12.88×n / 0.1×2 ={(A5-A2)-(Ab5-Ab2)-(B5-B2)}×1.605×n However, the following values ​​are optional, and the elapsed time can be changed as appropriate. A5: absorbance value after 5 minutes of reaction, A2: absorbance value after 2 minutes of reaction, Ab5: absorbance value after 5 minutes of blank (no enzyme), Ab2: absorbance value after 2 minutes of blank (no enzyme), B5: absorbance value after 5 minutes of blank (no substrate), B2: absorbance value after 2 minutes of blank (no substrate), 12.88: millimolar extinction coefficient of quinoneimine dye, 2: conversion factor (1 mole of quinoneimine dye corresponds to 2 moles of n-butylamine), n: dilution factor of target sample, 3.1: total volume (mL or g), 0.1: volume of target sample (mL or g).

[0020] The type of frozen noodles produced in the present invention is not particularly limited, and may be any type generally known in the art, such as Chinese noodles, udon, soba, and pasta.

[0021] Ordinary noodle ingredients can be used for the frozen noodles of the present invention. Specifically, grain flours include wheat flour (including durum flour), buckwheat flour, barley flour, rice flour, and various starches such as potato starch, tapioca starch, and corn starch, and these can be used alone or in combination. The starch can also be raw starch, pregelatinized starch, acetylated starch, etherified starch, cross-linked starch, and other processed starches. Commonly used ingredients in noodle production, such as salt, alkaline agents, various thickeners, noodle quality improvers, edible oils and fats, and various pigments such as carotene pigments, can be added to these grain flours. These can be added in powder form together with the raw material flour, or dissolved or suspended in the mixing water before addition.

[0022] The method for adding the eggshell membrane composition or lysyl oxidase of the present invention to frozen noodles is not particularly limited, but it is preferable that the composition be uniformly distributed throughout the noodle dough, and the composition can be added to the noodle dough together with other ingredients. For example, the composition can be premixed with grain flour or other powdered ingredients to form a noodle dough, or the composition can be predissolved in kneading water and then mixed.

[0023] The amount of the eggshell membrane composition or lysyl oxidase of the present invention added to frozen noodles is not particularly limited, but is generally 0.5 to 5 parts by weight, preferably 0.5 to 3 parts by weight, and more preferably 0.5 to 1 part by weight, per 100 parts by weight of grain flour. If the amount added is 0.5 parts by weight or less, the frozen noodles will not develop firmness. On the other hand, if the amount added is more than 5 parts by weight, the boiling process will take longer, the noodles will have a core, or they will lose their flexibility and become brittle.

[0024] The above ingredients are kneaded to produce noodle dough. More specifically, auxiliary ingredient flours such as noodle quality improvers are added to main ingredient flours such as wheat flour or starch, and the powder mixture is then mixed. After this, kneading water, which is water in which auxiliary ingredients such as salt and alkali agents have been dissolved, is added, and the ingredients are thoroughly kneaded in a mixer to uniformly mix them to produce dough.

[0025] Next, noodle strands are produced from the dough produced in the kneading step. Production methods may be conventional, including a method in which the dough is extruded using an extruder or the like to produce noodle strands, or a method in which the dough is formed into a noodle sheet by compounding or the like, and then rolled multiple times using a roll to produce a predetermined noodle sheet thickness, and then the noodle sheet is cut out using a cutting roll or knife cutter known as a cutting blade to produce noodle strands. In this case, the noodle sheet may be produced using an extruder, and then rolled and cut out, or multiple noodle sheets may be combined to produce a noodle sheet with a multilayer structure, and then rolled and cut out. When producing extruded noodle sheets or extruded noodle strands using an extruder or the like, it is preferable to do so under reduced pressure. The produced noodle strands are then cut to an appropriate length to produce fresh noodles.

[0026] Furthermore, the present invention can be used not only for fresh noodles, but also for dried noodles such as pasta, udon, soba, and Chinese noodles. Conventional noodle ingredients can be used for the dried noodles of the present invention, and additives such as cereal flour starch, modified starch, salt, alkaline agents, thickeners, noodle quality improvers, edible oils and fats, and colorings can be added. These can be added as powders together with the raw material flour, or dissolved or suspended in the kneading water. The method for adding the eggshell membrane composition or lysyl oxidase of the present invention to dried noodles is not particularly limited, as long as it is uniformly distributed within the noodle dough. It can be added to the noodle dough together with other ingredients. For example, it can be premixed or predissolved in powdered raw materials or kneading water. When adding the eggshell membrane composition or lysyl oxidase of the present invention to dried noodles, there are no particular limitations, but the composition can be added in an amount of 0.5 to 5 parts by weight, preferably 0.5 to 3 parts by weight, and more preferably 0.5 to 1 part by weight per 100 parts by weight of grain flour. The ingredients are kneaded to produce a noodle dough, and noodle strands are then prepared. The noodle strands may be produced according to standard methods, and may be rolled or cut depending on the production method. The produced noodle strands are cut to an appropriate length and dried either naturally or mechanically to form dried noodles.

[0027] The prepared fresh or dried noodles are then packed into a bucket and boiled before the freezing step to produce boiled noodles. The preferred boiling temperature and time vary depending on the type and thickness of the noodles, so a suitable temperature can be set appropriately to suit the desired texture, with a preferred temperature of approximately 90 to 100°C being preferred. The addition of the eggshell membrane composition or lysyl oxidase of the present invention is effective in reducing the boiling time. The boiling time can be set appropriately depending on the type, thickness, and amount of noodles to be boiled, but it is possible to shorten the boiling time compared to normal boiling times; for example, a reduction of 30% or more is possible compared to when the eggshell membrane composition or lysyl oxidase is not added. Specifically, for noodles that normally require 8 minutes of boiling time, a reduction of 3 minutes or more is possible. As with the boiling time, the reduction time can be adjusted depending on the type, thickness, and amount of noodles to be boiled. By shortening the boiling time, the noodles can be easily transferred to the next step, the water-washing step, and the temperature of the noodles can be easily lowered, lowering the temperature before the start of freezing and reducing the load on the freezing machine. In other words, the present invention also includes a method for shortening the boiling time before freezing in the production of frozen noodles.

[0028] The preferred water absorption rate of boiled noodles after boiling varies depending on the type of noodle, but it is preferably 40 to 55% lower by weight than the water absorption rate of the noodles at the time of consumption (after reboiling). For example, in the case of frozen udon, the water absorption rate of noodles at the time of consumption is in the 130% weight range, while the water absorption rate of noodles after boiling (before freezing) is preferably around 90% by weight. If the water absorption rate after boiling is too low, the core is likely to remain and the noodle strands will lose their flexibility. If the water absorption rate is too high, there is a high possibility that the noodles will melt during boiling and reboiling. Note that the water absorption rate in this invention is expressed as the ratio of the amount of water absorbed after boiling to the weight of the raw or dried noodles before boiling, and a detailed calculation method is described in the Examples. Furthermore, normally, as the boiling time is extended, the amount of water absorbed by noodles increases, and the noodles are likely to become stretched. However, according to this invention, even when the boiling time is extended, the noodles are less likely to stretch, and the firmness and softness of the noodles are easily maintained.

[0029] After the boiling process, the boiled noodles are drained and then rinsed and cooled. If the noodles are left as they are after the boiling process, the moisture on the surface of the noodles will evaporate and dry, causing the noodles to stick together, and the moisture inside the noodles will become increasingly homogenized, resulting in a stretched texture. Therefore, by rapidly cooling and tightening the noodles by rinsing and cooling, it is possible to suppress the homogenization of the moisture and prevent deterioration of the texture, as well as to remove the slime on the surface of the noodles and prevent the noodle strands from sticking together. However, rapid tightening of the noodles can sometimes harden the surface texture. For udon and other noodles, the texture of frozen noodles that have been rinsed and cooled is often preferred, but for noodles such as Chinese noodles, which have a soft surface and a springy, hard core, frozen noodles that have been rinsed and cooled are undesirable in terms of noodle texture.

[0030] Next, the boiled noodles are suitably filled, wrapped, inspected for foreign matter, and then frozen in a freezer. The method of freezing is not particularly limited, but may be an air blast spiral freezer, tunnel freezer, quick freezer, etc. It is preferable to rapidly freeze the frozen product at a temperature of about -30 to -60°C.

[0031] The frozen noodles frozen in the freezing process can be further packaged in plastic packaging, and if necessary, soup, oil, condiments, etc. can be added separately and sold as a frozen food (frozen noodles).

[0032] The frozen noodles produced according to the present invention can be easily consumed by cooking them in a pot with hot water or by cooking them in a microwave oven. When re-boiling in hot water, the boiling time and temperature are not particularly limited, but boiling in water at 90 to 100°C for about 1 minute per 100 to 300 g is preferred.

[0033] Based on the above aspects, frozen noodles containing an eggshell membrane composition having lysyl oxidase activity can be produced as quick-cook frozen noodles, which shortens the boiling process before freezing, thereby improving production efficiency. Despite being quick-cooked, these frozen noodles produce noodles that are firm and have no core. Furthermore, since the noodles do not absorb excessive water when reboiled before eating, the texture of the noodles remains the same as before freezing, allowing for a satisfying eating experience. The texture of such noodles can be confirmed by their breaking stress. Specifically, a rheometer or texture analyzer (plunger: wedge-shaped) is used to compare noodles with and without the addition of an eggshell membrane composition or lysyl oxidase. Detailed methods can be found in the Examples section.

[0034] The present embodiment will be described in more detail below with reference to examples.

[0035] (Method for preparing eggshell membrane composition) Eggshell membranes were peeled from chicken eggshells, freeze-dried, and pulverized in a blender to prepare an eggshell membrane composition. The enzyme activity of lysyl oxidase contained in the eggshell membrane was measured by the plate assay method described in paragraph 0015, and was found to be 0.25 units / g.

[0036] (Preparation of comparison samples) Transglutaminase was used as a comparative sample to compare with the eggshell membrane composition containing lysyl oxidase. The test sample used was a product manufactured by SOBOL. The enzymatic activity of the transglutaminase was measured and found to be 35.5 units / g. The activity of the transglutaminase was measured according to the following method. Reagent A: Substrate solution 30mM benzyloxycarbonyl-L-glutaminylglycine 100mM hydroxylamine 10mM reduced glutathione 200mM Tris-HCl buffer (pH 6.0) Reagent B: Stop solution 3N hydrochloric acid 12% trichloroacetic acid 5% FeCl3·6H2O (dissolved in 0.1N HCl) A 1:1:1 mixture of the above solutions is designated as Reagent B. 500 μL of reagent A was added to 50 μL of the test sample, mixed, and reacted for 10 minutes at 37°C. Reagent B was added to the reaction mixture to stop the reaction, and the Fe complex was generated. The absorbance at 525 nm was measured. For the control group, the absorbance was measured in the same manner using a test sample that had been heat-inactivated in advance, and the difference in absorbance between the two test groups was calculated. A calibration curve was prepared using L-glutamic acid γ-monohydroxamic acid, and the amount of hydroxamic acid produced was calculated from the absorbance difference. The enzyme activity required to produce 1 μmol of hydroxamic acid per minute was defined as 1 unit.

[0037] (Making frozen udon) The raw material composition and manufacturing process of the frozen udon are shown in Tables 1 and 2, respectively.

[0038] [Table 1]

[0039] [Table 2]

[0040] The evaluation items of the frozen udon noodles were the breaking stress, water absorption rate, and surface observation of the noodle strings.

[0041] (breaking stress) Measurement method The rupture stress was measured for udon noodles after boiling treatments in the frozen noodle manufacturing process shown in Table 2: "Boiling (1)": before freezing (boiling time 8 minutes) and "Boiling (2)": after freezing (boiling time 1 minute after boiling). A rheometer was used to measure the rupture stress, and the measurement conditions were set as follows: Plunger: Wedge-shaped Compression speed: 60mm / min

[0042] result Figure 1 shows the breaking stress of udon noodles after boiling and before freezing. In "Boiling (1)," the breaking stress of comparison group 1 was significantly higher than that of the control, suggesting that the udon noodles had a firmer texture. No significant difference was observed between comparison group 1 and the control. In "Boiling (2)," the breaking stress of both comparison group 1 and test group 1 was significantly higher than that of the control, indicating that firmness was maintained even after reboiling after freezing. Sensory evaluation of the "Boiling (2)" udon noodles revealed that the control noodles had a fuzzy appearance, tended to stick to the strainer after boiling, and had a soggy texture. Comparison group 1 had a firmer texture, but was somewhat hard-cored and lacked elasticity. Furthermore, the test group had a powdery and rough surface. Test group 1 had a moderate firmness, a chewy texture, and a glossy surface. Breaking stress ratio for comparison group 1 (boiled (1)) = 0.85 (N) / 0.56 (N) = 1.5 Breaking stress ratio for "boiling (1)" in test area 1 = 0.59 (N) / 0.56 (N) = 1.1 Breaking stress ratio for comparison group 1 (boiled (2)) = 0.55 (N) / 0.32 (N) = 1.7 Breaking stress ratio for "boiling (2)" in Experimental Area 1 = 0.59 (N) / 0.56 (N) = 1.3

[0043] (Water absorption rate) Measurement method The water absorption rate was measured for the udon noodles "boiled (1)" and "boiled (2)" in the frozen noodle manufacturing process shown in Table 2. The water absorption rate was calculated using the following formula. Water absorption = Weight of raw or dried noodles after boiling (g) - Weight of raw or dried noodles before boiling (g) Water absorption rate = Water absorption amount (g) / Weight of raw or dried noodles before boiling (g) x 100

[0044] result Table 3 shows the water absorption rates of udon noodles in "Boiling (1)" and "Boiling (2)" before and after freezing. After "Boiling (1)," the control had the highest water absorption rate, followed by Experimental Group 1 and Comparative Group 1. After "Boiling (2)," only the control showed a high water absorption rate. The control, which underwent "boiling (1)," "freezing," and "boiling (2)" after "boiling (1)," demonstrated that the noodles themselves rapidly absorbed the boiling water. Comparative Group 1 and Experimental Group 1 did not show a rapid absorption of boiling water between "boiling (1)" and "boiling (2)." However, Experimental Group 1 had a higher water absorption rate in "boiling (1)," indicating a tendency for it to absorb boiling water more easily. In particular, boiling before freezing indicated that it absorbed a moderate amount of boiling water. However, Experimental Group 1 did not show as rapid absorption of boiling water as the control, from before to after freezing. Water absorption ratio in comparison group 1 (boiled (1)) = 83 (%) / 101 (%) = 0.82 Water absorption ratio in "boiling (1)" in test area 1 = 94(N) / 101(N) = 0.93 Water absorption ratio in "Boiling (2)" of comparison group 1 = 0.55(N) / 0.32(N) = 0.80 Water absorption ratio for "boiling (2)" in test area 1 = 0.59(N) / 0.56(N) = 0.85

[0045] [Table 3]

[0046] (Observation of the surface of the noodle strings) Observation method The surface of the udon noodles before eating (after freezing and re-boiling) was observed under a microscope.

[0047] result Microscope images of the udon noodles from each test group are shown in Figure 2. Only in test area 1 was the surface of the udon noodles shiny.

[0048] Summary of results The control results showed that, using conventional ingredients and manufacturing methods, freezing after boiling (1) weakened the noodle structure, resulting in a soggy, loss of firmness at the time of eating. Under these conditions, the effects of freezing damage were significant, and sensory characteristics were also poor. The results of comparison group 1 and experimental group 1 indicated that adding an enzyme that forms cross-linking structures in proteins significantly improved the freezing damage observed in the control. The addition of an eggshell membrane composition containing transglutaminase or lysyl oxidase reduced water absorption throughout the entire process, with little effect from freezing and boiling. Comparing comparison group 1 and experimental group 1 revealed significant differences in sensory evaluation. Even after two boiling processes, comparison group 1 retained a core, lost flexibility, and retained a powdery and rough surface, while experimental group 1 maintained a moderate firmness and a smooth, glossy surface. Furthermore, experimental group 1 showed little difference in water absorption between boiling (1) and boiling (2). Comparison group 1 retained a firm texture even after multiple boiling processes, but experimental group 1 absorbed water appropriately even at the "boiling (1)" stage, retaining an easy-to-eat texture, and the noodle structure did not break down or become soggy even after multiple boiling processes. Therefore, it was determined that lysyl oxidase is capable of producing frozen noodles with a firm core and a suitable texture, even with a short boiling time or number of times, and is suitable for quick-cooking frozen noodles.

[0049] (Boiling time comparison) A comparison was made of the quick-boiling times for frozen udon noodles containing an eggshell membrane composition containing transglutaminase and lysyl oxidase. The frozen udon noodles were made using the same ingredient composition ratios as in Table 1, and were produced under the same conditions as in Table 2 except for the boiling time. The boiling times were 5, 7.5, and 10 minutes.

[0050] Sensory evaluation was conducted using a 5-point scale to assess the firmness and smoothness of the noodles. Each sensory evaluation item was defined as follows, with the closer the evaluation score was to 5, the more the evaluation sample (udon noodles) exhibited the defined properties, and the closer the score was to 1, the more different it was from the defined properties. "Noodle firmness": The noodles have no core, are moderately chewy or elastic, and are flexible. "Smooth": The surface of the noodles is free of unpleasant slime or roughness, does not stick to each other, and is easy to separate.

[0051] (result) The results of the sensory evaluation for each test group are shown in Table 4. In comparison group 1, where transglutaminase was added, the noodles were hard and felt a bit firm. As the boiling time increased, the noodles became more elastic, but they remained hard even after 10 minutes. The surface of the noodles was also rough, resulting in poor palatability. On the other hand, in experimental group 1, where an eggshell membrane composition containing lysyl oxidase was added, noodles with a moderate firmness were obtained after 5 minutes, and the noodles also showed desirable properties of being firm. Furthermore, these properties remained unchanged from 5 to 10 minutes, allowing for the production of noodles with a stable, highly palatable taste, and preventing them from becoming too soft when boiled. [Table 4]

Claims

1. A method for producing quick-cooking frozen noodles, comprising the step of adding 0.5 to 5.0 parts by weight of lysyl oxidase having a lysyl oxidase activity of 0.1 unit / g or more to 0.5 unit / g per 100 parts by weight of grain flour.

2. A method for producing quick-cooking frozen noodles, comprising the step of adding 0.5 to 5.0 parts by weight of an eggshell membrane composition having a lysyl oxidase activity of 0.1 unit / g or more to 0.5 unit / g or more per 100 parts by weight of grain flour.

3. Quick-boil frozen noodles containing lysyl oxidase or an eggshell membrane composition having lysyl oxidase activity.

4. The quick-cooking frozen noodles according to claim 3, wherein under measurement conditions (a) to (c), the breaking stress ratio, represented by the following formula, is 1.0 or more and less than 1.5 before freezing, and is 1.2 or more and less than 1.7 after re-boiling. (a) Measuring equipment: rheometer or texture analyzer (b) Plunger: Wedge-shaped (c) Compression speed: 60 mm / min Breaking stress ratio (N1 / N2) = Breaking stress (N1) of frozen noodles obtained by the production method described in claim 1 or claim 2 / Breaking stress (N2) of frozen noodles to which the lysyl oxidase described in claim 1 or the eggshell membrane composition described in claim 2 has not been added

5. 4. The quick-cooking frozen noodles according to claim 3, wherein the water absorption ratio, represented by the following formula, is 0.85 or more and 0.95 or less before freezing and 0.81 or more and 0.86 or less after re-boiling. Water absorption ratio = Water absorption (%) of frozen noodles obtained by the manufacturing method of claim 1 or claim 2 / Water absorption (%) of frozen noodles to which the lysyl oxidase of claim 1 or the eggshell membrane composition of claim 2 has not been added

6. A method for shortening the boiling time of frozen noodles, characterized by adding 0.5 to 5.0 parts by weight of a lysyl oxidase or eggshell membrane composition having a lysyl oxidase activity of 0.1 unit / g or more to 0.5 unit / g per 100 parts by weight of grain flour.

7. A method for inhibiting boiled soggy noodles, comprising adding 0.5 to 5.0 parts by weight of a lysyl oxidase or eggshell membrane composition having a lysyl oxidase activity of 0.1 unit / g or more to 0.5 unit / g per 100 parts by weight of grain flour.

Images