Method for improving quality of dry rice noodles based on in-situ damp-heat recombination drying technology

Abstract

The invention discloses a method for improving the quality of dry rice noodles based on an in-situ damp-heat recombination drying technology, and relates to the technical field of food processing. By regulating and controlling the water content and the treatment temperature of the rice noodles and optimizing the multi-scale structure of the starch, the cooking performance, the texture property and the microstructure uniformity of the dry rice noodles are improved, and the quality defects of traditional dry rice noodles are overcome; the cooking loss of the dry rice noodles is reduced from 17.15% to 6.19%, starch dissolution is greatly reduced, and the yield is improved; the tensile strength is improved by 44.5%, and the chewiness is improved by 1.68 times, so that the rice noodles are chewy in taste, resistant to boiling and not burnt; the microstructure is more uniform, the phenomena of loose edge and hard core in the center after rehydration are reduced, and the eating experience is improved; chemical reagents do not need to be added, the label cleaning requirement is met, the method can be integrated on an existing drying production line (the transformation cost is smaller than or equal to 15%), the pilot plant test yield reaches 98.7% and is improved by 13.4% compared with a traditional process, and the production period is shortened by 20%.

Description

Technical Field

[0001] The invention relates to the technical field of food processing, and in particular to a method for improving the quality of dry rice noodles based on in-situ moist heat recombinant drying technology. Background Art

[0002] Rice noodles are a traditional staple food in Asian countries. Fresh rice noodles are susceptible to microbial contamination and spoilage due to their high moisture content (>50g / 100g). Therefore, fresh rice noodles are usually dried to make dry rice noodles to extend their shelf life. However, the dry rice noodles made by traditional drying methods have poor edible quality after rehydration. The main manifestations are: severe starch dissolution during steaming and cooking, high cooking loss rate, and loose texture and lack of elasticity after cooking.

[0003] In order to improve the rehydration quality of dry rice noodles, additives (such as adding colloids or other starches) or chemically modified starch are often used, but these methods have food safety risks and high costs.

[0004] Therefore, a new solution to the above problems needs to be proposed. Summary of the Invention

[0005] The object of the present invention is to provide a method for improving the quality of dry rice noodles based on in-situ moist heat reorganization drying technology, so as to solve the technical problems raised in the background technology.

[0006] To achieve the above object, the present invention provides the following technical solution: a method for improving the quality of dry rice noodles based on in-situ moist heat reorganization drying technology, comprising at least the following steps:

[0007] S1: preparing fresh wet rice noodles, soaking indica rice and grinding it into rice slurry, and extruding it into fresh rice noodles through a screw extruder;

[0008] S2: Pre-drying to control moisture content;

[0009] S3: in situ moist heat reorganization (ITHR) treatment;

[0010] S4: final drying and stabilization are performed to obtain dry rice noodles.

[0011] Furthermore, the S1 at least includes the following steps:

[0012] Add indica rice with a starch content of ≥75% and a protein content of 8.5% to 9.0% to deionized water at a mass ratio of 1:1 and soak at 4°C for 12 hours;

[0013] The rice pulp was ground into a 55% moisture content using a JP-828A type refiner;

[0014] The product was extruded by a SZ-30 single-screw extruder (3 mm sieve hole, 95-100° C., screw speed 120 r / min), and aged at 4° C. for 24 hours.

[0015] Furthermore, the S2 at least includes the following steps: drying the fresh rice noodles in an oven at 45° C. to a moisture content of 20% to 35%.

[0016] Furthermore, the step S3 at least includes the following steps:

[0017] Place the rice noodles in a sealed pressure vessel, introduce saturated steam at a rate of 5 L / min, increase the pressure to 0.14 MPa within 3 minutes, and maintain at 110±2°C and 0.14 MPa for 120 minutes;

[0018] This process maintains pressure through an automatic pressure-stabilizing valve, promoting the rearrangement of starch molecules in rice flour, enhancing intermolecular interactions, and strengthening the starch gel network.

[0019] Furthermore, the S4 at least includes the following steps:

[0020] First, the rice noodles processed in S3 are cooled and depressurized;

[0021] After cooling and depressurizing, dry the mixture at 60°C and 50%±5% relative humidity to a moisture content of 13%±1%.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The present invention optimizes the multi-scale structure of starch by regulating the moisture content and processing temperature of rice noodles, thereby improving the cooking performance, texture characteristics and microstructure uniformity of dry rice noodles, and solving the quality defects of traditional dry rice noodles.

[0024] The cooking loss of dry rice noodles was reduced from 17.15% to 6.19%, significantly reducing starch dissolution and improving the yield rate. The tensile strength was increased by 44.5%, and the chewiness was increased by 1.68 times, making the rice noodles more chewy and resistant to cooking. The microstructure was more uniform, reducing the loose edges and hard core after rehydration, improving the eating experience.

[0025] No chemical reagents are required, meeting clean label requirements, and can be integrated into existing drying production lines (renovation costs ≤ 15%). The pilot yield reaches 98.7%, an increase of 13.4% over traditional processes, and the production cycle is shortened by 20%. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 is the XRD pattern of the present invention;

[0028] Figure 2 It is a comparison diagram of the present invention. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0030] Example 1:

[0031] See also Figure 1-Figure 2 A method for improving the quality of dry rice noodles based on in-situ moist heat reorganization drying technology comprises at least the following steps:

[0032] S1: preparing fresh wet rice noodles, soaking indica rice and grinding it into rice slurry, and extruding it into fresh rice noodles through a screw extruder;

[0033] S2: Pre-drying to control moisture content;

[0034] S3: in situ moist heat reorganization (ITHR) treatment;

[0035] S4: final drying and stabilization are performed to obtain dry rice noodles.

[0036] Said S1 at least comprises the following steps:

[0037] Add indica rice with a starch content of ≥75% and a protein content of 8.5% to 9.0% to deionized water at a mass ratio of 1:1 and soak at 4°C for 12 hours;

[0038] The rice pulp was ground into a 55% moisture content using a JP-828A type refiner;

[0039] The product was extruded by a SZ-30 single-screw extruder (3 mm sieve hole, 95-100° C., screw speed 120 r / min), and aged at 4° C. for 24 hours.

[0040] S2 at least comprises the following steps: drying the fresh rice flour in an oven at 45° C. to a moisture content of 20% to 35%.

[0041] S3 includes at least the following steps:

[0042] Place the rice noodles in a sealed pressure vessel, introduce saturated steam at a rate of 5 L / min, increase the pressure to 0.14 MPa within 3 minutes, and maintain at 110±2°C and 0.14 MPa for 120 minutes;

[0043] This process maintains pressure through an automatic pressure-stabilizing valve, promoting the rearrangement of starch molecules in rice flour, enhancing intermolecular interactions, and strengthening the starch gel network.

[0044] S4 includes at least the following steps:

[0045] First, the rice noodles processed in S3 are cooled and depressurized;

[0046] After cooling and depressurizing, dry the mixture at 60°C and 50%±5% relative humidity to a moisture content of 13%±1%.

[0047] In situ heat and moisture reorganization (ITHR) is introduced during the drying process, using the synergistic effect of saturated steam, pressure and high temperature (110°C) to promote the rearrangement of starch molecules, enhance the hydrogen bonding between molecules, and form a more ordered crystalline structure and a dense semi-crystalline layer. Specifically, the high temperature of 110°C destroys the hydrogen bonds in the amorphous region of starch, and the pressure of 0.14MPa ensures uniform heat conduction, forming a more ordered crystalline network during the cooling process (XRD shows a 31.7% increase in relative crystallinity), while strengthening the three-dimensional structure of the gel network (SEM observation pore size is reduced from 12.6μm to 4.2μm). This structural change limits the dissolution of starch during the rehydration process, reduces the cooking loss rate, and at the same time improves the deformation resistance and elasticity of rice noodles and improves texture properties.

[0048]

[0049] Note: Data in the same column with different lowercase letters indicate significant differences (p<0.05). ITHR-20% means the moisture content of rice flour before ITHR treatment was 20%, and the same applies to the following data.

[0050] Example 2:

[0051] This embodiment proposes a specific processing process based on the above embodiment 1:

[0052] 500g of indica rice was soaked in 468.5mL of deionized water at 4°C for 12 hours. The soaked rice was ground into rice slurry using a pulp grinder, and the moisture content of the rice slurry was 55g / 100g. Rice noodles were extruded using a single-screw extruder with an extrusion mesh diameter of 3mm and an extrusion temperature of 95-100°C. The extruded wet rice noodles were aged in a 4°C environment for 24 hours. The wet rice noodles were then dried to a moisture content of 20%, placed in an in-situ wet heat recombinant treatment device, saturated steam was introduced, and the ambient temperature was maintained at 110°C for 2 hours. The treated sample was placed in a constant temperature and humidity incubator at 60°C and a relative humidity of 50% to balance the moisture to about 13%, thereby obtaining dry rice noodles.

[0053] Based on the above embodiment, a comparison of ITHR processing with different aging times is proposed

[0054] Aging 12 hours group: The steps were the same as in Example 1, except that the aging time was changed to 12 hours and the other conditions remained unchanged to obtain ITHR-12h dry rice noodles.

[0055] Aging 36 h group: The aging time was changed to 36 h, and the other conditions remained unchanged to prepare ITHR-36h dry rice noodles.

[0056] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A method for improving the quality of dry rice noodles based on in-situ moist heat reorganization drying technology, characterized in that: At least the following steps are included: S1: preparing fresh wet rice noodles, soaking indica rice and grinding it into rice slurry, and extruding it into fresh rice noodles through a screw extruder; S2: Pre-drying to control moisture content; S3: In-situ wet heat reorganization treatment; S4: final drying and stabilization are performed to obtain dry rice noodles.

2. A method for improving the quality of dry rice noodles based on in-situ moist heat reorganization drying technology according to claim 1, characterized in that: Said S1 at least comprises the following steps: Add indica rice with a starch content of ≥75% and a protein content of 8.5% to 9.0% to deionized water at a mass ratio of 1:1 and soak at 4°C for 12 hours; The rice pulp was ground into a 55% moisture content using a JP-828A type refiner; The product was extruded by a SZ-30 single-screw extruder and aged at 4°C for 24 hours.

3. A method for improving the quality of dry rice noodles based on in-situ moist heat reorganization drying technology according to claim 1, characterized in that: The step S2 at least comprises the following steps: drying the fresh rice flour in an oven at 45° C. to a moisture content of 20% to 35%.

4. A method for improving the quality of dry rice noodles based on in-situ moist heat reorganization drying technology according to claim 1, characterized in that: The S3 at least includes the following steps: Place the rice noodles in a sealed pressure vessel, introduce saturated steam at a rate of 5 L / min, increase the pressure to 0.14 MPa within 3 minutes, and maintain at 110±2°C and 0.14 MPa for 120 minutes; This process maintains pressure through an automatic pressure-stabilizing valve, promoting the rearrangement of starch molecules in rice flour, enhancing intermolecular interactions, and strengthening the starch gel network.

5. A method for improving the quality of dry rice noodles based on in-situ moist heat reorganization drying technology according to claim 1, characterized in that: The S4 at least includes the following steps: First, the rice noodles processed in S3 are cooled and depressurized; After cooling and depressurizing, dry the mixture at 60°C and 50%±5% relative humidity to a moisture content of 13%±1%.

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