Fresh and wet brown rice noodles capable of prolonging freshness by cooperating with composite fence technology and preparation method of fresh and wet brown rice noodles

Abstract

The invention discloses fresh and wet brown rice noodles capable of prolonging freshness by cooperating with a composite fence technology and a preparation method of the fresh and wet brown rice noodles, and relates to the technical field of food freshness preservation. Comprising the following steps: treating brown rice flour by using superheated steam, then transferring the treated brown rice flour into double-screw extrusion equipment, performing curing and extrusion forming, performing standing and aging treatment, soaking the treated brown rice flour in an acid solution, performing vacuum packaging, and performing high-temperature sterilization to obtain the fresh and wet brown rice noodles. The fresh and wet brown rice noodles are subjected to fresh-keeping treatment by adopting a multi-element physical-chemical fresh-keeping method cooperating with a composite fence technology, so that growth and reproduction of microorganisms in the storage process of the fresh and wet brown rice noodles can be effectively inhibited, the shelf life of the fresh and wet brown rice noodles is further prolonged, and meanwhile, the eating quality of the fresh and wet brown rice noodles is improved; the noodles have the advantages of being good in texture performance, good in taste and low in breaking rate and cooking loss rate.

Description

Technical Field

[0001] The invention relates to the technical field of food preservation, in particular to fresh wet brown rice noodles using a coordinated composite fence technology to extend the preservation time and a preparation method thereof. Background Art

[0002] Rice noodles, also known as rice vermicelli, etc., are mainly made from rice and are processed into strips or threads through a series of processes. As a functional staple food rich in dietary fiber, vitamins and minerals, fresh wet brown rice noodles have been favored by the market in recent years due to their health properties. However, brown rice has a high fat content (about 2.5-3.5%) and strong lipase activity, which can easily cause oxidative rancidity. At the same time, fresh wet rice noodles, as a typical high-moisture, high-starch-based food system, are extremely susceptible to microbial contamination during production, transportation and storage, causing product spoilage, short storage time and poor storage quality, which seriously restricts the development of the fresh wet brown rice noodle industry.

[0003] Currently, fresh wet rice noodles are typically preserved through physical or chemical methods. However, physical methods require high temperatures and prolonged heat treatment, significantly reducing the noodles' edible quality. Chemical methods, on the other hand, suffer from poor antibacterial efficacy and food safety concerns. Traditional preservation techniques have limited effectiveness in extending the shelf life of brown rice noodles, severely restricting their industrial production and market distribution. Therefore, new, combined preservation methods are needed to better extend the shelf life of fresh wet brown rice noodles. Summary of the Invention

[0004] The invention provides fresh wet brown rice noodles with extended freshness by using a synergistic composite barrier technology and a preparation method thereof, so as to effectively extend the shelf life of the fresh wet brown rice noodles, improve the texture performance, and improve the edible quality of the fresh wet brown rice noodles.

[0005] In order to solve the above technical problems, one of the objects of the present invention is to provide a method for preparing fresh wet brown rice noodles with extended shelf life using a composite barrier technology, comprising the following steps:

[0006] (1) brown rice powder is placed in superheated steam equipment and processed, controlled temperature is 110-130 ℃, processing time 3-10min, and drying obtains superheated steam and processes brown rice powder;

[0007] (2) the superheated steam treated brown rice powder is transferred to a twin-screw extruder for slaking, and extrusion molding obtains shaped rice noodles;

[0008] (3) subjecting the shaped rice noodles to a static aging treatment to obtain aged rice noodles;

[0009] (4) dipping the aged rice noodles in an acid solution comprising an acid having a mass concentration of 1% to 5% and a balance of water, wherein the acid is lactic acid and / or citric acid, and the dipping time is 1 to 8 minutes to obtain acid-soaked rice noodles;

[0010] (5) vacuum-packing the acid-soaked rice noodles and then sterilizing them at high temperature to obtain fresh wet brown rice noodles.

[0011] The present invention adopts a synergistic composite fence technology in the preparation process of fresh wet brown rice noodles. Through superheated steam treatment, the microbial cell protein is denatured and the enzyme is inactivated, and the total bacterial count and mold in the raw material are completely killed, thereby avoiding the reproduction of microorganisms in the subsequent long-term constant temperature and humidity aging stage and delaying fat oxidation and rancidity. At the same time, acid immersion changes the pH of the fresh wet rice noodle system to inhibit the growth and reproduction of microorganisms without affecting the texture and properties of the rice noodles. Vacuum packaging is used to remove the air in the packaging bag to inhibit the growth and reproduction of microorganisms. High-temperature sterilization uses high temperature to inhibit the growth and reproduction or kill heat-resistant microorganisms. A multi-physical-chemical preservation method is used to effectively inhibit the growth and reproduction of microorganisms during the storage of fresh wet brown rice noodles, thereby extending the shelf life of fresh wet brown rice noodles.

[0012] At the same time, superheated steam treatment can promote partial gelatinization of starch molecules and form amylose-lipid complexes, enhance the stability of the rice noodle gel network structure, and improve hardness, elasticity and tensile strength. Superheated steam treatment can cross-link rice protein to form a denser gel network structure, thereby further improving the hardness, elasticity and taste of rice noodles, and improving the edible quality of fresh wet brown rice noodles. It has the advantages of good texture performance, good taste, low breakage rate and cooking loss rate.

[0013] As a preferred embodiment, in step (4), the acid is lactic acid and citric acid in a mass ratio of 1:(1-3).

[0014] The present application adopts a composite acid immersion of lactic acid and citric acid to treat rice noodles. The composite acid immersion can avoid affecting the texture of rice noodles and has a higher sterilization effect. The total colony count and mold count of the prepared fresh wet rice noodles in the 28-day microbial test can be further reduced, far below the local standard requirements, and the hardness, chewiness and tensile strength of the fresh wet rice noodles are further improved, and the texture performance is excellent.

[0015] As a preferred embodiment, in step (1), the mesh size of the brown rice flour is above 50 meshes.

[0016] As a preferred embodiment, in step (1), the method for preparing brown rice flour comprises the following steps: shelling brown rice, then adding water to wash, draining at room temperature, then grinding, and passing through a 50-200 mesh sieve to obtain brown rice flour.

[0017] As a preferred embodiment, in step (1), the brown rice is indica rice of the "Yongxian 409" variety.

[0018] As a preferred solution, in step (1), the steam consumption during the treatment by the superheated steam equipment is 40-50 kg / h.

[0019] As a preferred embodiment, in step (2), the twin-screw extruder has a total of 8 temperature zones, and the temperatures of the 8 temperature zones are 55-65°C, 75-85°C, 95-105°C, 105-115°C, 105-115°C, 75-85°C, 65-75°C, and 55-65°C, respectively; the screw speed is 150-250r / min, the solid feed rate is 6-9kg / h, the liquid feed rate is 1-4kg / h, and the moisture mass fraction in the feed liquid is 20%-60%.

[0020] As a preferred solution, in step (3), the static aging temperature is 20° C., the static aging humidity is 90%, and the static time is 6 h.

[0021] As a preferred solution, in step (5), the temperature of high temperature sterilization is 85-95°C and the time is 20-40 minutes.

[0022] In order to solve the above technical problems, one of the purposes of the present invention is to provide a preparation method of fresh wet brown rice noodles with synergistic composite barrier technology to extend the shelf life.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The present application adopts a multi-physical-chemical preservation method in conjunction with a composite barrier technology to carry out a preservation treatment on fresh wet brown rice noodles, which can effectively inhibit the growth and reproduction of microorganisms during the storage of fresh wet brown rice noodles, thereby extending the shelf life of the fresh wet brown rice noodles and improving the edible quality of the fresh wet brown rice noodles. The noodles have the advantages of good texture performance, good taste, low breakage rate and cooking loss rate.

[0025] 2. The preparation process of the fresh wet brown rice noodles of the present application adopts a collaborative composite fence technology. The microbial cell protein is denatured and the enzyme is inactivated by superheated steam treatment, and the total colony count and mold in the raw material are completely killed to avoid the reproduction of microorganisms in the subsequent long-term constant temperature and humidity aging stage. At the same time, acid leaching is used to change the pH value of the fresh wet rice noodle system to inhibit the growth and reproduction of microorganisms without affecting the texture and properties of the rice noodles. Vacuum packaging is used to remove the air in the packaging bag to inhibit the growth and reproduction of microorganisms. High-temperature sterilization utilizes high temperature to inhibit the growth and reproduction or kill heat-resistant microorganisms, ultimately achieving the effect of extending the shelf life.

[0026] 3. The pre-superheated steam treatment of the brown rice flour of the present application can promote the partial gelatinization of starch molecules and form an amylose-lipid complex, enhance the stability of the rice noodle gel network structure, and improve the hardness, elasticity and tensile strength. The superheated steam treatment can also cross-link the rice protein to form a denser gel network structure, thereby further improving the hardness, elasticity and mouthfeel of the rice noodles and improving the edible quality of the fresh wet brown rice noodles. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 : A schematic flow diagram of a method for preparing fresh wet brown rice noodles with extended shelf life using a collaborative composite barrier technology in an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0029] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value within any stated value or stated range, and each smaller range between any other stated value or intermediate value within the stated range, is also encompassed within the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0030] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0031] To further illustrate the present invention, the present invention is described in detail below with reference to the following examples, but they should not be construed as limiting the scope of protection of the present invention. Unless otherwise specified, the raw materials used in the following examples and comparative examples of the present application are all commercially available, and the same raw materials are used in parallel experiments.

[0032] Example 1

[0033] A preparation method of fresh wet brown rice noodles with extended shelf life using a synergistic composite fence technology, such as Figure 1 As shown, the following steps are included:

[0034] (1) brown rice raw material is pulverized: select " Yongxian 409 " kind indica rice and adopt rice huller to carry out shelling, obtain brown rice raw material, add distilled water subsequently and clean to remove impurity, be placed under room temperature and drain, adopt disintegrator to pulverize after draining, and cross 100 mesh sieve to obtain brown rice powder;

[0035] (2) superheated steam treatment: brown rice powder is placed in superheated steam equipment, steam consumption 45kg / h, temperature 120 ℃, time 5min, subsequently brown rice powder is placed in baking oven 40 ℃ of drying 2h after, obtain superheated steam treatment brown rice powder;

[0036] (3) screw extrusion slaking: superheated steam is processed brown rice powder and is transferred in the twin screw extruder, twin screw extruder has 8 temperature zones, and the temperature in 8 temperature zones is respectively 60 ℃, 80 ℃, 100 ℃, 110 ℃, 110 ℃, 80 ℃, 70 ℃, 60 ℃, screw speed is 200r / min, solid feed rate is 7.5kg / h, and liquid feed rate is 2.5kg / h, and moisture mass fraction is 40% in the feed liquid, makes it slaking under hot environment, extrusion moulding, obtains shaped rice noodles;

[0037] (4) Static aging: The formed rice noodles were transferred to a constant temperature and humidity incubator for aging at 20° C. and 90% humidity for 6 h until the rice noodles were free of adhesion and translucent, thereby obtaining aged rice noodles.

[0038] (5) acid soaking: the aged rice noodles were immersed in an acid solution containing 3.0% lactic acid and the balance water at room temperature for 3 min to obtain acid soaked rice noodles;

[0039] (6) Vacuum packaging and thermal sterilization: The acid-soaked rice noodles were packaged in ziplock bags, sealed with a vacuum packaging machine, and then placed in a water bath for sterilization at a temperature of 90°C for 30 min to obtain the finished brown rice noodles. The sample was named SS120-LA-VP-TS.

[0040] Example 2

[0041] A method for preparing fresh wet brown rice noodles with extended shelf life using a synergistic composite barrier technology, wherein each step and the reagents, equipment, and process parameters used in each step are the same as those in Example 1, except that, in step (5), the acid solution comprises lactic acid with a mass concentration of 1%, citric acid with a mass concentration of 2%, and water as the remainder; and in step (6), the final brown rice noodle product is named SS120-LC-VP-TS.

[0042] Comparative Example 1

[0043] A method for preparing fresh wet brown rice noodles with extended freshness preservation by using a synergistic composite fence technology comprises the following steps:

[0044] (1) brown rice raw material is pulverized: select " Yongxian 409 " kind indica rice and adopt rice huller to carry out shelling, obtain brown rice raw material, add distilled water subsequently and clean to remove impurity, be placed under room temperature and drain, adopt disintegrator to pulverize after draining, and cross 100 mesh sieve to obtain brown rice powder;

[0045] (2) screw extrusion slaking: brown rice flour is transferred in the twin screw extruder, twin screw extruder has 8 temperature zones, and the temperature in 8 temperature zones is respectively 60 ℃, 80 ℃, 100 ℃, 110 ℃, 110 ℃, 80 ℃, 70 ℃, 60 ℃, screw speed is 200r / min, solid feed rate is 7.5kg / h, and liquid feed rate is 2.5kg / h, and moisture mass fraction is 40% in the feed liquid, makes it slaking under hot environment, extrusion moulding, obtains shaped rice noodles;

[0046] (3) Static aging: The formed rice noodles were transferred to a constant temperature and humidity incubator for static aging at 20°C and 90% humidity for 6 h, until the rice noodles were free of adhesion and translucent, and the finished brown rice noodles were obtained. The sample was named Control.

[0047] Comparative Example 2

[0048] A method for preparing fresh wet brown rice noodles with extended freshness preservation by using a synergistic composite fence technology comprises the following steps:

[0049] (1) brown rice raw material is pulverized: select " Yongxian 409 " kind indica rice and adopt rice huller to carry out shelling, obtain brown rice raw material, add distilled water subsequently and clean to remove impurity, be placed under room temperature and drain, adopt disintegrator to pulverize after draining, and cross 100 mesh sieve to obtain brown rice powder;

[0050] (2) screw extrusion slaking: brown rice flour is transferred in the twin screw extruder, twin screw extruder has 8 temperature zones, and the temperature in 8 temperature zones is respectively 60 ℃, 80 ℃, 100 ℃, 110 ℃, 110 ℃, 80 ℃, 70 ℃, 60 ℃, screw speed is 200r / min, solid feed rate is 7.5kg / h, and liquid feed rate is 2.5kg / h, and moisture mass fraction is 40% in the feed liquid, makes it slaking under hot environment, extrusion moulding, obtains shaped rice noodles;

[0051] (3) Static aging: The formed rice noodles were transferred to a constant temperature and humidity incubator for aging at 20° C. and 90% humidity for 6 h until the rice noodles were free of adhesion and translucent, thereby obtaining aged rice noodles.

[0052] (4) re-steaming: re-steaming the aged rice noodles at a re-steaming temperature of 100° C. for 10 min to obtain re-steamed rice noodles;

[0053] (5) acid soaking: the re-steamed rice noodles were immersed in an acid solution at room temperature, wherein the acid solution comprised lactic acid with a mass concentration of 3.0% and the balance of water for 3 minutes to obtain acid soaked rice noodles;

[0054] (6) Vacuum packaging and thermal sterilization: The acid-soaked rice noodles were packaged in ziplock bags, sealed with a vacuum packaging machine, and then placed in a water bath for sterilization at a temperature of 90 °C for 30 min to obtain the finished brown rice noodles. The sample was named LA-VP-TS.

[0055] Comparative Example 3

[0056] A method for preparing fresh wet brown rice noodles with extended freshness preservation by using a synergistic composite fence technology comprises the following steps:

[0057] (1) brown rice raw material is pulverized: select " Yongxian 409 " kind indica rice and adopt rice huller to carry out shelling, obtain brown rice raw material, add distilled water subsequently and clean to remove impurity, be placed under room temperature and drain, adopt disintegrator to pulverize after draining, and cross 100 mesh sieve to obtain brown rice powder;

[0058] (2) superheated steam treatment: brown rice powder is placed in superheated steam equipment, steam consumption 45kg / h, temperature 120 ℃, time 5min, subsequently brown rice powder is placed in baking oven 40 ℃ of drying 2h after, obtain superheated steam treatment brown rice powder;

[0059] (3) screw extrusion slaking: superheated steam is processed brown rice powder and is transferred in the twin screw extruder, twin screw extruder has 8 temperature zones, and the temperature in 8 temperature zones is respectively 60 ℃, 80 ℃, 100 ℃, 110 ℃, 110 ℃, 80 ℃, 70 ℃, 60 ℃, screw speed is 200r / min, solid feed rate is 7.5kg / h, and liquid feed rate is 2.5kg / h, and moisture mass fraction is 40% in the feed liquid, makes it slaking under hot environment, extrusion moulding, obtains shaped rice noodles;

[0060] (4) Static aging: The formed rice noodles were transferred to a constant temperature and humidity incubator for aging at 20°C and 90% humidity for 6 h until the noodles were free of adhesion and in a translucent state. The finished brown rice noodles were obtained and the sample was named SS120.

[0061] Comparative Example 4

[0062] A method for preparing fresh wet brown rice noodles with extended freshness preservation by using a synergistic composite fence technology comprises the following steps:

[0063] (1) brown rice raw material is pulverized: select " Yongxian 409 " kind indica rice and adopt rice huller to carry out shelling, obtain brown rice raw material, add distilled water subsequently and clean to remove impurity, be placed under room temperature and drain, adopt disintegrator to pulverize after draining, and cross 100 mesh sieve to obtain brown rice powder;

[0064] (2) screw extrusion slaking: brown rice flour is transferred in the twin screw extruder, twin screw extruder has 8 temperature zones, and the temperature in 8 temperature zones is respectively 60 ℃, 80 ℃, 100 ℃, 110 ℃, 110 ℃, 80 ℃, 70 ℃, 60 ℃, screw speed is 200r / min, solid feed rate is 7.5kg / h, and liquid feed rate is 2.5kg / h, and moisture mass fraction is 40% in the feed liquid, makes it slaking under hot environment, extrusion moulding, obtains shaped rice noodles;

[0065] (3) Static aging: The formed rice noodles were transferred to a constant temperature and humidity incubator for aging at 20° C. and 90% humidity for 6 h until the rice noodles were free of adhesion and translucent, thereby obtaining aged rice noodles.

[0066] (4) Organic acid pickling: The aged rice noodles were placed in an acid solution at room temperature for immersion. The acid solution included 3.0% lactic acid and the balance water. The immersion time was 3 min to obtain the finished brown rice noodles. The sample was named LA.

[0067] Comparative Example 5

[0068] A method for preparing fresh wet brown rice noodles with extended freshness preservation by using a synergistic composite fence technology comprises the following steps:

[0069] (1) brown rice raw material is pulverized: select " Yongxian 409 " kind indica rice and adopt rice huller to carry out shelling, obtain brown rice raw material, add distilled water subsequently and clean to remove impurity, be placed under room temperature and drain, adopt disintegrator to pulverize after draining, and cross 100 mesh sieve to obtain brown rice powder;

[0070] (2) screw extrusion slaking: brown rice flour is transferred in the twin screw extruder, twin screw extruder has 8 temperature zones, and the temperature in 8 temperature zones is respectively 60 ℃, 80 ℃, 100 ℃, 110 ℃, 110 ℃, 80 ℃, 70 ℃, 60 ℃, screw speed is 200r / min, solid feed rate is 7.5kg / h, and liquid feed rate is 2.5kg / h, and moisture mass fraction is 40% in the feed liquid, makes it slaking under hot environment, extrusion moulding, obtains shaped rice noodles;

[0071] (3) Static aging: The formed rice noodles were transferred to a constant temperature and humidity incubator for aging at 20° C. and 90% humidity for 6 h until the rice noodles were free of adhesion and translucent, thereby obtaining aged rice noodles.

[0072] (4) Vacuum packaging: The aged rice noodles were packaged in ziplock bags and sealed using a vacuum packaging machine to obtain the finished brown rice noodles. The sample was named VP.

[0073] Comparative Example 6

[0074] A method for preparing fresh wet brown rice noodles with extended freshness preservation by using a synergistic composite fence technology comprises the following steps:

[0075] (1) brown rice raw material is pulverized: select " Yongxian 409 " kind indica rice and adopt rice huller to carry out shelling, obtain brown rice raw material, add distilled water subsequently and clean to remove impurity, be placed under room temperature and drain, adopt disintegrator to pulverize after draining, and cross 100 mesh sieve to obtain brown rice powder;

[0076] (2) screw extrusion slaking: brown rice flour is transferred in the twin screw extruder, twin screw extruder has 8 temperature zones, and the temperature in 8 temperature zones is respectively 60 ℃, 80 ℃, 100 ℃, 110 ℃, 110 ℃, 80 ℃, 70 ℃, 60 ℃, screw speed is 200r / min, solid feed rate is 7.5kg / h, and liquid feed rate is 2.5kg / h, and moisture mass fraction is 40% in the feed liquid, makes it slaking under hot environment, extrusion moulding, obtains shaped rice noodles;

[0077] (3) Static aging: The formed rice noodles were transferred to a constant temperature and humidity incubator for aging at 20° C. and 90% humidity for 6 h until the rice noodles were free of adhesion and translucent, thereby obtaining aged rice noodles.

[0078] (4) Thermal sterilization: The acid-soaked rice noodles were packaged in ziplock bags and then placed in a water bath for sterilization at a temperature of 90 °C for 30 min to obtain the finished brown rice noodles. The sample was named TS.

[0079] Comparative Example 7

[0080] A method for preparing fresh wet brown rice noodles with extended freshness-keeping by using a synergistic composite fence technology, wherein each step and the reagents, equipment and process parameters used in each step are the same as those in Example 1, except that, in step (2), brown rice flour is placed in a superheated steam device with a steam consumption of 45 kg / h, a temperature of about 100 DEG C and a time of 5 min, and then the brown rice flour is placed in an oven at 40 DEG C and dried for 2 h to obtain superheated steam-treated brown rice flour; and in step (6), the final brown rice noodle product is named SS100-LA-VP-TS.

[0081] Performance testing

[0082] 1. Microbial colony index of fresh wet brown rice noodles, the experimental method is as follows:

[0083] (1) The method for determining the total colony count shall refer to GB 4789.2-2016 “National Food Safety Standard - Determination of the Total Colony Count by Microbiological Examination of Foods”;

[0084] (2) The mold determination method refers to GB 4789.15-2016 "National Food Safety Standard Food Microbiological Examination Mold and Yeast Enumeration";

[0085] Evaluation of experimental results: The most intuitive and powerful evidence of whether food is spoiled and edible is whether the number of microorganisms exceeds the standard. Referring to local standards such as Guangxi (DBS 45 / 050-2021) and Yunnan (DBS 53 / 017-2014), it is considered that when the total colony count exceeds 61g CFU / g or the total mold count exceeds 2.21g CFU / g, it is used as the end point of the shelf life of the microbial index. The microbial indicators of fresh wet brown rice noodles prepared in the embodiment and comparative example are shown in Table 1.

[0086] 2. The cooking quality of fresh wet brown rice noodles, the experimental method is as follows:

[0087] (1) Broken rice noodles: 20 fresh wet brown rice noodles with a length greater than 20 cm were selected and placed in a 1000 mL beaker. 600 mL of boiling water was added thereto, followed by heating on an electric stove. After the optimal cooking time (2 min 30 s) was completed, the noodles were cooled in water for 30 s and then placed in a test sieve to drain for 5 min. Fresh wet brown rice noodles with a length less than or equal to 10.0 cm and greater than 10.0 cm were selected and weighed as M1 and M2, respectively. The broken rice noodles were calculated according to the following formula. Each sample was measured three times.

[0088]

[0089] Where M1 is the mass of fresh wet brown rice noodles with a length less than or equal to 10.0 cm, g; M2 is the mass of fresh wet brown rice noodles with a length greater than 10.0 cm, g.

[0090] (2) Cooking loss rate: The moisture content of fresh wet brown rice noodle samples was measured and recorded as M. Ten fresh wet brown rice noodles with a length of 20 cm were selected and weighed as M0. The fresh wet brown rice noodles were placed in a 1000 mL beaker and 600 mL of boiling water was added. After steaming for the optimal cooking time (2 min 30 s), the cooked rice noodles were placed in a drying dish and dried at 105°C to a constant weight M1. The cooking loss rate was calculated according to the following formula. The measurement was repeated three times for each sample.

[0091]

[0092] Wherein, M is the moisture content of fresh wet brown rice noodles, %; M0 is the mass of fresh wet brown rice noodles before cooking, g; M1 is the dry weight of fresh wet brown rice noodles after cooking, g.

[0093] Experimental Results Evaluation: Cooking quality is an important criterion for measuring rice noodle quality, and breakage rate and cooking loss are commonly used to indicate the cooking quality of fresh wet rice noodles. According to the Hunan local standard (DB43 / 156-2007), the shelf life of fresh wet rice noodles is considered to end when the breakage rate is ≥15% and the cooking loss is ≥20%. The cooking quality of fresh wet brown rice noodles prepared in the Examples and Comparative Examples is shown in Table 2.

[0094] 3. Texture characteristics of fresh wet brown rice noodles. The experimental method is as follows:

[0095] (1) Texture Profile Analysis (TPA) Experiment: Fifteen fresh wet brown rice noodles of approximately 20 cm in length were selected and steamed for the optimal cooking time (2 min 30 s). The noodles were then placed on a test sieve to drain for 5 min. Five fresh wet brown rice noodles of approximately 5 cm in length were then selected and placed on a texture analyzer using a probe model P / 36R. The pre-test speed was 2 mm / s, the mid-test speed was 1 mm / s, the post-test speed was 1 mm / s, the compression ratio was 50%, the compression interval was 3 s, and the trigger force was 0.04905 N. Each sample was tested three times and the average value was taken.

[0096] (2) Tensile properties test: Fifteen fresh wet brown rice noodles, approximately 20 cm in length, were selected and steamed for the optimal cooking time (2 min 30 s). The noodles were then placed on a test sieve to drain for 5 min. Five fresh wet brown rice noodles, approximately 5 cm in length, were then placed on a texture analyzer using probe model A / SPR, a test speed of 2 mm / s, a post-test speed of 10 mm / s, and a distance of 80 mm. Each sample was tested three times, and the average value was taken.

[0097] Experimental results: Texture properties are one of the key quality indicators that determine product acceptance. By performing texture profile analysis (TPA) and tensile testing on fresh wet rice noodles, the texture changes of fresh wet brown rice noodles during storage were studied. The test results of the texture properties of the fresh wet brown rice noodles prepared in the examples and comparative examples are shown in Table 3.

[0098] Table 1 - Microbial indicators of fresh wet brown rice noodles prepared in the present application examples and comparative examples

[0099]

[0100]

[0101] Table 2 - Cooking quality results of fresh wet brown rice noodles prepared in the present application examples and comparative examples

[0102]

[0103]

[0104] Table 3 - Test results of texture characteristics of fresh wet brown rice noodles prepared in Examples and Comparative Examples of the present application

[0105]

[0106]

[0107]

[0108] As shown in Table 1, with the extension of storage time, the total colony count and mold count of each group of fresh wet rice noodles showed an upward trend; compared with Comparative Example 1, the total colony count and mold count of fresh wet rice noodles in Comparative Example 3, which used superheated steam treatment (SS120), Comparative Example 4, which used lactic acid pickling (LA), Comparative Example 5, which used vacuum packaging (VP), and Comparative Example 6, which used thermal sterilization (TS), were significantly reduced. Compared with the single treatments of Comparative Examples 3-6, Example 1 of the present application, based on the multi-element physical-chemical fresh-keeping composite barrier technology, combined superheated steam treatment, lactic acid pickling, vacuum packaging, and thermal sterilization, further significantly reduced the total colony count and mold count of fresh wet rice noodles. This may be due to the superheated steam treatment denaturing microbial cell proteins and inactivating enzymes, completely eliminating the total bacterial count and mold in the raw material while also delaying fat oxidative rancidity. The organic acid pickling process changes the pH of the fresh wet rice noodle system, inhibiting microbial growth and reproduction. Vacuum packaging removes air from the packaging bag, inhibiting microbial growth and reproduction. The high temperature of thermal sterilization inhibits the growth and reproduction of heat-resistant microorganisms, thereby extending the shelf life of the rice noodles. This demonstrates that the multi-physical-chemical preservation method can synergistically produce a composite barrier effect, effectively inhibiting the growth and reproduction of microorganisms during storage and extending the shelf life of fresh wet brown rice noodles. Sample SS120-LC-VP-TS from Example 2, treated with composite acid pickling, produced the lowest total bacterial count and mold counts. After 28 days of storage, the total bacterial count and mold count were 1.57 lg CFU / g and <1 lg CFU / g, respectively, far below local standards.

[0109] As shown in Table 2, the breakage rate and cooking loss rate of each group of fresh wet rice noodles showed an upward trend with the extension of storage time. Compared with Comparative Example 1, the breakage rate and cooking loss rate of the fresh wet rice noodles in Comparative Example 3, which used superheated steam treatment (SS120), Comparative Example 4, which used lactic acid pickling (LA), Comparative Example 5, which used vacuum packaging (VP), and Comparative Example 6, which used thermal sterilization (TS), were significantly reduced. Compared with the single treatments of Comparative Examples 3-6, the breakage rate and cooking loss rate of the fresh wet rice noodles in Example 1, based on the multi-element physical-chemical preservation composite barrier technology, were further significantly reduced. This demonstrates that the multi-element physical-chemical preservation method can synergistically produce a composite barrier effect, which not only extends the shelf life of the fresh wet rice noodles, but also enhances the gel strength of the fresh wet rice noodles, thereby maintaining the cooking quality of the fresh wet rice noodles during storage. The breakage rate and cooking loss of fresh wet rice noodles increased during storage. This may be due to the growth and metabolism of microorganisms, which degrades starch and disrupts the starch gel structure within the rice noodles. Furthermore, this may be due to the long-term aging of the starch system within the rice noodles. Sample SS120-LC-VP-TS from Example 2 had the lowest breakage rate and cooking loss, reaching 7.35% and 9.06% after 28 days of storage, respectively, significantly below local standards.

[0110] As shown in Table 3, the hardness, chewiness, and tensile strength of the fresh rice noodles in each group increased with extended storage time. Compared with Comparative Example 1, the hardness, chewiness, and tensile strength of the fresh rice noodles in Comparative Example 3, which used superheated steam treatment (SS120), Comparative Example 4, which used lactic acid pickling (LA), Comparative Example 5, which used vacuum packaging (VP), and Comparative Example 6, which used thermal sterilization (TS), all showed significant improvements. Compared with the single treatments in Comparative Examples 3-6, the hardness, chewiness, and tensile strength of the fresh rice noodles in Example 1, which utilizes the multi-element physical-chemical preservation composite barrier technology, were further significantly improved. This demonstrates that the multi-element physical-chemical preservation method can synergistically create a composite barrier effect, not only extending the shelf life of the fresh rice noodles but also enhancing their gel strength, thereby maintaining their texture during storage. The increasing hardness, chewiness, and tensile strength of the fresh rice noodles during storage may be due to the long-term aging of the starch in the rice noodles and the recrystallization of amylopectin. Among them, the sample SS120-LC-VP-TS fresh wet rice noodles of Example 2 had the highest hardness, chewiness and tensile strength. When stored for 28 days, the hardness, chewiness and tensile strength were 2598.48g, 2130.80g and 255.40g respectively.

[0111] As shown in Table 1-2, compared with Example 1, the sample LA-VP-TS of Comparative Example 2 is not subjected to superheated steam treatment, but is subjected to 100 DEG C of re-steaming after standing for aging treatment. The superheated steam treatment of the present application embodiment 1 has instantaneous high temperature and low moisture characteristics, and namely, brown rice powder is subjected to high temperature treatment in the raw material processing stage, can quickly penetrate the brown rice powder particles, destroy microbial cell structure, make microbial cell protein denaturation, enzyme inactivation, thoroughly kill the total bacterial count and the mold in the raw material, avoid breeding microorganisms in the aging stage of subsequent long-term constant temperature and humidity. Although re-steaming can kill microorganisms to a certain extent after the aging of the rice flour of Comparative Example 2, the long-term constant temperature and humidity conditions of the early stage aging stage are easily suitable for microbial reproduction, so that the total bacterial count and the mold quantity of the final prepared fresh wet brown rice noodle are improved, and the storage time is reduced.

[0112] As shown in Table 3, the superheated steam treatment of Example 1 of the present application can promote the partial gelatinization of starch molecules and form amylose-lipid complexes, enhance the stability of the rice noodle gel network structure, and improve hardness, elasticity and tensile strength; secondly, the superheated steam treatment can crosslink rice protein to form a denser gel network structure, thereby further improving the hardness, elasticity and mouthfeel of rice noodles. The starch in the aging stage of Comparative Example 2 will recrystallize, and the high temperature and high humidity environment of the re-steaming process easily causes excessive gelatinization of starch, thereby destroying the crystalline region of starch molecules, making the rice noodle structure loose and easy to break, resulting in a reduction in its hardness, elasticity and tensile strength; secondly, the denaturation of rice protein in the re-steaming process after aging is easily soluble in the hydrothermal environment, and the supporting effect of the gel network structure formed is weakened, resulting in the hardness, chewiness and tensile strength of the rice noodles of Comparative Example 2 being not as good as those of Example 1.

[0113] In addition, the steam temperature of sample SS120-LA-VP-TS in Example 1 was controlled at about 120°C during the superheated steam treatment, while the steam temperature of sample SS100-LA-VP-TS in Comparative Example 7 was controlled at about 100°C during the superheated steam treatment. These temperatures were lower than those in Example 1, resulting in the total bacterial count and mold count of the rice noodles in Comparative Example 7 being higher than those in Example 1, shortening the storage time, and the hardness, chewiness, and tensile strength of the rice noodles in Comparative Example 7 being inferior to those in Example 1. This indicates that the higher the temperature at which the brown rice flour is treated with superheated steam, the higher the degree of microbial cell protein denaturation and enzyme inactivation in a short period of time, and the better the effect of enhancing the gel network structure of the rice noodles, thereby achieving the effects of reducing microorganisms and extending shelf life, and maximizing the hardness, chewiness, and tensile strength of the rice noodles.

[0114] The specific embodiments described above are intended to limit the scope of protection of the present invention, including the objectives, technical solutions, and beneficial effects of the present invention. It is particularly noted that any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention by those skilled in the art should be included within the scope of protection of the present invention.

Claims

1. A method for preparing fresh wet brown rice noodles with extended shelf life using a synergistic composite barrier technology, characterized in that: The following steps are involved: (1) brown rice powder is placed in superheated steam equipment and processed, controlled temperature is 110-130 ℃, processing time 3-10min, and drying obtains superheated steam and processes brown rice powder; (2) the superheated steam treated brown rice powder is transferred to a twin-screw extruder for slaking, and extrusion molding obtains shaped rice noodles; (3) subjecting the shaped rice noodles to a static aging treatment to obtain aged rice noodles; (4) dipping the aged rice noodles in an acid solution comprising an acid having a mass concentration of 1% to 5% and a balance of water, wherein the acid is lactic acid and / or citric acid, and the dipping time is 1 to 8 minutes to obtain acid-soaked rice noodles; (5) vacuum-packing the acid-soaked rice noodles and then sterilizing them at high temperature to obtain fresh wet brown rice noodles.

2. The method for preparing fresh wet brown rice noodles with extended freshness preservation by the collaborative composite barrier technology as claimed in claim 1, wherein In step (4), the acid is lactic acid and citric acid in a mass ratio of 1:(1-3).

3. The preparation method of fresh wet brown rice noodles with extended freshness preservation by the collaborative composite barrier technology as claimed in claim 1, characterized in that, In step (1), the mesh size of the brown rice flour is above 50 meshes.

4. The method for preparing fresh wet brown rice noodles with extended freshness preservation by the collaborative composite barrier technology as claimed in claim 1, wherein In step (1), the method for preparing brown rice flour comprises the following steps: shelling brown rice, then washing it with water, draining it at room temperature, then grinding it, and passing it through a 50-200 mesh sieve to obtain brown rice flour.

5. The method for preparing fresh wet brown rice noodles with extended freshness preservation by the collaborative composite barrier technology as claimed in claim 4, characterized in that, In step (1), the brown rice is indica rice of the "Yongxian 409" variety.

6. The method for preparing fresh wet brown rice noodles with extended freshness preservation by using the collaborative composite barrier technology as claimed in claim 1, wherein: In step (1), the steam consumption during the treatment by the superheated steam equipment is 40-50 kg / h.

7. The method for preparing fresh wet brown rice noodles with extended freshness preservation by using the collaborative composite barrier technology as claimed in claim 1, wherein: In step (2), the twin-screw extruder has 8 temperature zones, and the temperatures of the 8 temperature zones are 55-65°C, 75-85°C, 95-105°C, 105-115°C, 105-115°C, 75-85°C, 65-75°C, and 55-65°C, respectively. The screw speed is 150-250r / min, the solid feed rate is 6-9kg / h, the liquid feed rate is 1-4kg / h, and the moisture mass fraction in the liquid is 20%-60%.

8. The method for preparing fresh wet brown rice noodles with extended freshness preservation by using the collaborative composite barrier technology as claimed in claim 1, characterized in that: In step (3), the static aging temperature is 20° C., the static aging humidity is 90%, and the static time is 6 hours.

9. The method for preparing fresh wet brown rice noodles with extended freshness preservation by using the collaborative composite barrier technology as claimed in claim 1, wherein: In step (5), the temperature of high temperature sterilization is 85-95°C and the time is 20-40 minutes.

10. Fresh wet brown rice noodles with extended freshness-keeping using the synergistic composite barrier technology, prepared by the method for preparing fresh wet brown rice noodles with extended freshness-keeping using the synergistic composite barrier technology as claimed in any one of claims 1 to 9.

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