Application of composite dietary fiber composition in improving cooking quality of sea rice

Abstract

The invention discloses an application of a composite dietary fiber composition in improving the cooking quality of sea rice. The composite dietary fiber composition is prepared by granulating raw materials including polydextrose, inulin and fructo-oligosaccharide. The composite dietary fiber composition has a microstructure similar to a sphere, and the dissolving property of the composite dietary fiber composition is remarkably improved. Aiming at harder sea rice, the composite dietary fiber composition is added into the sea rice during cooking, and statistical analysis according to a general linear model proves that the cooking time of the sea rice can be effectively shortened, the hardness of the rice is reduced, and the softness and taste of the rice are improved, so that the planting of the sea rice is promoted.

Description

Technical Field

[0001] The present invention belongs to the technical field of dietary fiber application, and more specifically, relates to the application of a composite dietary fiber composition in improving the cooking quality of sea rice. Background Art

[0002] Rice is the staple food for two-thirds of the world's population. It is estimated that by 2050, the global population will grow to 9.1 billion, and food production needs to increase by about 70% on the basis of current production, of which rice production needs to increase by at least 60%. To maintain a stable supply of food, one solution is to reduce the post-harvest losses of major food crops, and another potential solution is to increase the yield of food crops by promoting high-yield food varieties and their corresponding planting techniques in arable land. The new seawater-adaptable and salt-tolerant rice variety 86 (seawater rice) discovered by Chinese rice breeding experts in 1986 has the ability to tolerate 0.6% alkaline soil. Seawater rice can grow normally around saline-alkali land and salt lakes, has salt tolerance, can soil organic matter, and improve saline-alkali land. If seawater rice planting is promoted to 6.67 million hectares, the yield will reach 300kg per mu, increasing 300 million tons of food. Promoting seawater rice planting can effectively alleviate global food security issues. However, due to the dense seed coat structure of sea rice grains, consumers need to soak the rice for a long time when making rice, and the cooking time is long, and the rice tastes rough, which hinders the consumption of sea rice and the development of the industry.

[0003] Therefore, it is imperative to develop an effective method to solve the cooking quality of sea rice. Summary of the invention

[0004] Based on the problems existing in the prior art, the purpose of the present invention is to provide an application of a composite dietary fiber composition in improving the cooking quality of sea rice, which can shorten the cooking time of sea rice, effectively improve the harder texture of sea rice, and enhance the softness and taste of rice.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The invention provides an application of a composite dietary fiber composition in improving the cooking quality of sea rice. The composite dietary fiber composition is obtained by granulating polydextrose, inulin and oligofructose as raw materials.

[0007] Furthermore, in terms of mass percentage, the raw materials contain 30%-40% polydextrose, 30%-35% inulin, and 30%-35% oligofructose.

[0008] Furthermore, in terms of mass percentage, the raw materials contain 34% polydextrose, 33% inulin and 33% oligofructose.

[0009] Furthermore, the composite dietary fiber composition is prepared by uniformly mixing polydextrose, inulin and oligofructose raw materials, and then adding a small amount of water vapor or alcohol as a binder for granulation.

[0010] Furthermore, the improvement of the cooking quality of sea rice includes one or more of the following:

[0011] (1) Reduce the cooking time of sea rice;

[0012] (2) Increase the dissolution of cooked sea rice solids;

[0013] (3) Reduce the hardness, stickiness and chewiness of cooked sea rice while maintaining adhesion, cohesion and elasticity;

[0014] (4) Inhibiting starch retrogradation and aging of cooked sea rice;

[0015] (5) Improve the softness of rice cooked from sea rice.

[0016] Furthermore, the method of improving the softness of cooked sea rice includes affecting the starch structure, protein secondary structure and microstructure of the rice.

[0017] Furthermore, the composite dietary fiber composition is added to the washed sea rice, mixed evenly, and then the rice is cooked in an electric rice cooker.

[0018] Furthermore, the added amount of the composite dietary fiber composition is 3-10% of the mass of the sea rice.

[0019] The beneficial effects of the present invention are as follows:

[0020] The composite dietary fiber composition of the present invention can reduce the cooking time of sea rice, reduce the hardness and texture of rice, inhibit starch retrogradation and prolong the shelf life. In addition, it can also improve the taste of rice made from sea rice, increase the dietary fiber content of rice food, reduce the incidence of type II diabetes among rice consumers, and thus promote the cultivation of sea rice. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0022] Figure 1 The scanning electron microscope microstructure of the composite dietary fiber composition is shown (1000 times);

[0023] Figure 2A diagram showing the effect of adding a composite dietary fiber composition on the microstructure of cooked rice (5000 times); wherein A, C and E are NJ variety rice, B, D and F are sea rice SQ rice; A and B are control samples, C and D are added with 5% of the composite dietary fiber composition; E and F are added with 10% of the composite dietary fiber composition. DETAILED DESCRIPTION

[0024] In order to more clearly illustrate the present invention, the present invention is further described below in conjunction with preferred embodiments and accompanying drawings. It should be understood by those skilled in the art that the content specifically described below is illustrative and non-restrictive, and should not be used to limit the scope of protection of the present invention. The preparation methods in the present invention are conventional methods unless otherwise specified. The raw materials used can be obtained from public commercial channels or prepared according to the prior art unless otherwise specified.

[0025] Example 1 Composite dietary fiber composition formula

[0026] The formula of the composite dietary fiber composition of the present invention mainly comprises the following components in percentage by weight: 30%-40% of polydextrose, 30%-35% of inulin and 30%-35% of oligofructose. After the raw materials are evenly mixed, a small amount of water vapor or alcohol is added as a binder for granulation to obtain the composite dietary fiber composition of the present invention.

[0027] Table 1. Formula of composite dietary fiber composition

[0028] Figure 1 The figure is a schematic diagram of the scanning electron microscope microstructure of the composite dietary fiber composition No. 1 (1000 times). Figure 1 It can be seen from the figure that the composite dietary fiber composition of the present invention is approximately spherical, and the small spheres can be bonded and aggregated into larger spheres. Compared with the amorphous powder polydextrose, the granulated composite dietary fiber composition dissolves quickly and dissolves immediately after a little stirring, while polydextrose dissolves in lumps, requiring the water temperature to be increased and vigorously stirred.

[0029] In addition, the No. 2 and No. 3 composite dietary fiber compositions also have the same microstructure.

[0030] Example 2 Effect of the composite dietary fiber composition on the cooking characteristics, rice texture, starch gelatinization, and the molecular structure and microstructure of rice starch and protein

[0031] Newly harvested japonica rice NJ5 was used as a control sample, and sea rice stored at low temperature in a test warehouse was used as a test sample. They were processed into rice on the same rice polishing machine, and then the composite dietary fiber composition was added to their rice grains or processed rice flour at a mass ratio of 0%, 3%, 5%, 7%, and 10%, and the influence of the composite dietary fiber composition on rice cooking characteristics, rice texture, starch gelatinization, and the molecular structure and microstructure of rice starch and protein was evaluated. In order to deeply analyze the influence of the two factors of rice variety and the amount of composite dietary fiber composition added on rice cooking characteristics and other measured indicators, the present invention adopts a general linear model and a univariate method for analysis, and analyzes the main effect interaction results.

[0032] 1. Effect of composite dietary fiber composition (No. 1) on cooking time and dissolution of cooking solids in sea rice

[0033] The method for determining the cooking time of rice is to weigh a rice sample (2 g) into a hard glass test tube (20 cm long × 2.5 cm diameter) and add 20 mL of distilled water. The glass test tube is then placed in a 16-grid test tube rack (16 cm long × 16 cm wide × 6.5 cm high) made of stainless steel wire and cooked in a boiling tap water bath. The optimal cooking time is determined by extracting individual rice grains at 0.5 min intervals during the cooking process, placing them on a glass plate, and pressing them one by one with the bottom of a spoon head until the white core disappears.

[0034] According to the above method, the rice sample (2g, m0) was cooked in 20mL distilled water for the optimal cooking time, after which the rice soup and the contents were transferred to a weighed 50ml round-bottom centrifuge tube (m1) for centrifugal cooling. The supernatant rice soup was drained, and the water seal on the surface of the contents was removed with filter paper. The total mass of the centrifuge tube and the contents (m2) was weighed, and the water absorption ratio was calculated using formula (1):

[0035] Moisture absorption ratio = (m2-m1-m0) / m0(1)

[0036] According to the above method, the rice sample (2g, m0) was cooked in 20mL distilled water for the optimal cooking time. The rice soup and the contents were transferred to a 50ml round-bottom centrifuge tube and centrifuged (4000r / min, 6min) to cool. The weight of the aluminum box (m3) was weighed, the supernatant of the centrifuge tube was transferred to the aluminum box, and 5ml of deionized water was added to the contents of the centrifuge tube and gently shaken. After centrifugation, the supernatant was transferred to the aluminum box. After drying at 110℃ for 15 hours, the weight of the aluminum box (m4) was weighed. The solid content of the rice soup was calculated using formula (2):

[0037] Cooking solid loss (mg / g) = (m4-m3) / m0×1000(2)

[0038] Table 2 Effect of the amount of composite dietary fiber composition added on rice cooking parameters

[0039]

[0040]

[0041] Note: Cooking time was measured in 5 parallels, and water absorption ratio and cooking solid dissolution were measured in 3 parallels. Different lowercase superscripts in the same column of the table indicate significant differences for the same rice sample (p < 0.05).

[0042] As can be seen from Table 2, the optimal cooking time of rice processed from newly harvested japonica rice NJ5 is shorter than that of sea rice SQ stored at low temperature for 3 years, and the cooking solid dissolution of the two is similar. As the addition amount of the composite dietary fiber composition of the present invention increases, the cooking time of both types of rice is reduced, and the cooking solid dissolution is increased. It can be seen that the composite dietary fiber composition of the present invention can not only improve the cooking time of japonica rice, but also improve the cooking time of sea rice.

[0043] Table 3 General linear model analysis (GLM) of the effect of the addition amount of composite dietary fiber composition on cooking parameters

[0044]

[0045] Note: Different lowercase superscripts in the same column indicate significant differences (p<0.05).

[0046] The results of the general linear model and univariate method analysis are shown in Table 3. Compared with the parameter values ​​when the composite dietary fiber composition is not added (control), the cooking time of japonica rice NJ5 is significantly shorter than that of the control, while the cooking time of sea rice SQ is higher than that of the control. The water absorption ratio of both types of rice is lower than that of the control, and the cooking solid dissolution is higher than that of the control. When 3-10% of the composite dietary fiber composition is added to a 2-gram rice sample, as the amount of the composite dietary fiber composition added increases, the rice cooking time and water absorption ratio are significantly reduced, and the loss of cooking solids increases. It can be seen that the hard texture of sea rice cooked rice can be improved by adding a composite dietary fiber composition, so as to achieve the purpose of a cooking time equivalent to that of NJ5 rice.

[0047] 2. Effect of composite dietary fiber composition (No. 1) on the texture characteristics of cooked sea rice

[0048] The method for determining the texture parameters of rice is to weigh 15g of rice into a 60ml aluminum box, add 20ml of distilled water to soak for 20min, place it in a boiling water pot and steam it for 40min, and then use it for texture determination immediately after 10min of simmering. The P / 36 probe is selected, and the test parameters are set as follows: the speed before the experiment is 1.0mm / s, the compression distance is 80mm, the test speed is 1.0mm / s, the dwell time is 2s, and the return speed is 2.0mm / s.

[0049] Table 4 Effect of the addition amount of composite dietary fiber composition on the texture characteristics of rice

[0050]

[0051]

[0052] Note: All the indicators in the table were measured in triplicate. Different lowercase superscripts in the same column of the table indicate significant differences for the same rice variety (p < 0.05).

[0053] As can be seen from Table 4, the hardness, adhesion, elasticity, gelatinization and chewiness of sea rice SQ rice are higher than those of polished round-grained rice NJ5 rice. The addition of the composite dietary fiber composition significantly reduces the hardness of NJ5 rice and can maintain other texture parameters; the addition of 3-10% of the composite dietary fiber composition significantly reduces the hardness, gelatinization and chewiness of sea rice SQ rice, can maintain elasticity, and maintain or even increase cohesion.

[0054] Table 5 General linear model analysis of the effect of the addition amount of composite dietary fiber composition on the texture parameters of rice

[0055]

[0056] Note: All the indicators in the table were measured in triplicate. Different lowercase superscripts in the same column of the table indicate significant differences (p < 0.05).

[0057] The general linear model and univariate method analysis showed the effect of rice variety and the amount of composite dietary fiber composition added on the texture of rice (Table 5). Compared with the values ​​of various parameters when no composite dietary fiber composition was added (control), the hardness of sea rice was significantly lower than that of the control, but the cohesion was significantly higher than that of the control; the hardness, adhesion, elasticity, gelatinization and chewiness of japonica rice NJ5 rice were significantly lower than those of sea rice. The addition of 3-10% composite dietary fiber composition significantly reduced the hardness, gelatinization and chewiness of the two types of rice, and was able to maintain adhesion, cohesion and elasticity. This shows that the addition of composite dietary fiber composition can improve the hard texture of sea rice.

[0058] 3. Effect of composite dietary fiber composition (No. 1) on the gelatinization characteristics of sea rice

[0059] The rapid viscosity tester (RVA) was used to measure the viscosity according to the method of GB / T 24852-2010. The program conditions were as follows: the mixture was kept at 50°C for 1 min, the initial speed was 960 r / min, and it was reduced to 160 r / min within 20 s; it was heated to 95°C (speed 12°C / min), and kept for 2.5 min; then it was cooled to 50°C (speed 18°C / min), and kept for 2 min.

[0060] Table 6 Effect of the addition amount of composite dietary fiber composition on the gelatinization characteristics of rice flour

[0061]

[0062]

[0063] Note: All the indicators in the table were measured in triplicate. Different lowercase superscripts in the same column of the table indicate significant differences for the same rice sample (p < 0.05).

[0064] It can be seen from Table 6 that the peak viscosity, attenuation value, regeneration value and gelatinization temperature of sea rice SQ rice flour are higher than those of japonica rice NJ5 rice flour. The composite dietary fiber composition with an addition amount of 3-10% can reduce the peak viscosity, attenuation value and regeneration value of rice flour paste, but increase the gelatinization temperature.

[0065] Table 7 General linear model analysis of the effect of the addition amount of composite dietary fiber composition on the gelatinization parameters of rice flour

[0066]

[0067] Note: All the indicators in the table were measured in triplicate. Different lowercase superscripts in the same column of the table indicate significant differences (p < 0.05).

[0068] The general linear model and univariate method analysis showed that the effect of rice variety and the amount of composite dietary fiber composition added on the gelatinization of rice flour (Table 7) was that compared with the values ​​of various parameters when the composite dietary fiber composition was not added (control), the peak viscosity, attenuation value, recovery value and gelatinization temperature of sea rice SQ rice flour gelatinization were significantly higher than the control, while the peak viscosity, attenuation value, final viscosity, recovery value and gelatinization temperature of japonica rice NJ5 rice flour were significantly lower than the control. The addition of 3-7% composite dietary fiber composition significantly reduced the peak viscosity, attenuation value, final viscosity and recovery value of rice flour paste, but increased the gelatinization temperature. This shows that the addition of composite dietary fiber composition can inhibit the starch recovery and aging of sea rice and prolong the shelf life.

[0069] 4. Effect of composite dietary fiber composition (No. 1) on starch structure and protein secondary structure of cooked sea rice

[0070] The cooked rice was first freeze-dried in a freeze dryer, and then the freeze-dried cooked rice sample was ground into powder. The powder sample was mixed with potassium bromide and ground, pressed into tablets, and Fourier infrared spectrometer was used in the range of 400-4000cm -1 All measurements were analyzed using OMNIC software.

[0071] Table 8 Effect of adding composite dietary fiber composition on the crystal structure of cooked rice starch

[0072]

[0073]

[0074] Note: All the indicators in the table were measured in triplicate. Different lowercase superscripts in the same column of the table indicate significant differences for the same rice variety (p < 0.05).

[0075] R 1022 / 995 , R 1047 / 1022 and R 1068 / 1022 They represent the short-range order of the amorphous region and the crystalline region on the surface of starch granules, and the interaction between protein and starch. As can be seen from Table 8, the addition of the composite dietary fiber composition reduces the short-range order of the amorphous region of starch granules, and increases the short-range order of the crystalline region of starch granules and the interaction between protein and starch, indicating that during the cooking process, the composite dietary fiber composition promotes the interaction between water molecules and protein and starch in rice grains, and the amylose leaks into the rice soup.

[0076] Table 9 General linear model analysis of the effect of composite dietary fiber composition addition on the crystal structure of cooked rice starch

[0077]

[0078] Note: All the indicators in the table were measured in triplicate. Different lowercase superscripts in the same column of the table indicate significant differences (p < 0.05).

[0079] The general linear model analysis results in Table 9 confirm that the addition of the composite dietary fiber composition reduces the short-range order of the amorphous region of starch granules, and increases the short-range order of the crystalline region of starch granules and the interaction between protein and starch.

[0080] Table 10 Effect of adding composite dietary fiber composition on the secondary structure of cooked rice protein

[0081]

[0082] Note: All the indicators in the table were measured in triplicate. Different lowercase superscripts in the same column of the table indicate significant differences (p < 0.05).

[0083] As can be seen from Table 10, there are four types of protein secondary structures in the cooked rice grains, namely α-helix, β-fold, β-turn and random curl. The addition of the composite dietary fiber composition basically maintained the α-helix conformation of NJ5 japonica rice and SQ sea rice; maintained the β-fold conformation of SQ rice, but reduced the β-fold of NJ5 rice; significantly increased the β-turn conformation of NJ5 rice, maintained the β-turn conformation of SQ rice; and significantly reduced the random curl conformation of both rices.

[0084] Table 11 General linear model analysis of the effect of composite dietary fiber composition addition on the secondary structure of cooked rice protein

[0085]

[0086] Note: All the indicators in the table were measured in triplicate. Different lowercase superscripts in the same column of the table indicate significant differences (p < 0.05).

[0087] The general linear model and univariate method were used to deeply analyze the effects of rice varieties and the amount of composite dietary fiber composition added on the secondary structure of rice protein. As shown in Table 11, compared with the control without the addition of composite dietary fiber composition, the percentage of α-helix and β-fold conformation of NJ5 and SQ rice remained unchanged; the addition of composite dietary fiber composition significantly increased the percentage of β-turn of sea rice SQ rice, significantly reduced the percentage of random curl, but maintained the percentage of β-turn and random curl of japonica rice NJ5 rice. After the addition of composite dietary fiber composition to sea rice, the addition of composite dietary fiber composition had the greatest impact on β-turn and random curl, with β-turn significantly increased, while random curl significantly decreased at an addition amount of 5-10%, indicating that the spatial random curl of polylysine was restricted, and the increase of β-turn on the surface of rice glutenin molecules changed the direction of the polypeptide chain, which helped the amylose to leak out of starch granules and the rice grains became soft.

[0088] 5. Effect of the composite dietary fiber composition (No. 1) on the microstructure of sea rice grains after cooking

[0089] After the steamed rice grains were freeze-dried, the longitudinal section of the endosperm close to the cortex was cut, and the cut surface of the grain was glued to a sample stand with conductive glue, and then platinum was sprayed in an ion sputtering instrument. The surface structure morphology of the sample was observed using a scanning electron microscope with an accelerating voltage of 4.0 kV and a magnification of 100-5000 times.

[0090] from Figure 2It can be seen that the cooked sea rice SQ rice has more pores and filaments, while the NJ5 rice has larger pores and thicker starch bodies. As the concentration of the composite dietary fiber composition increases, the honeycomb structure in the rice grains is gradually destroyed, making the pores larger and the holes shallower, indicating that the starch recrystallization degree decreases, the rice is soft and evenly expanded, and the chewiness decreases. Adding a composite dietary fiber composition can promote the interaction between rice grains and water molecules, starch is easy to gelatinize, and amylose is easy to leak into the rice soup, shortening the cooking time and significantly improving the softness of the rice.

[0091] We also conducted relevant experimental studies of Example 2 on the No. 2 and No. 3 composite dietary fiber compositions prepared in Example 1, and the results were consistent with those of Example 2.

[0092] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. Application of a composite dietary fiber composition in improving the cooking quality of sea rice, characterized in that: The composite dietary fiber composition is obtained by granulating polydextrose, inulin and oligofructose as raw materials.

2. The use according to claim 1, characterized in that: Calculated by mass percentage, the raw materials contain 30%-40% polydextrose, 30%-35% inulin, and 30%-35% oligofructose.

3. The use according to claim 1, characterized in that: Calculated by mass percentage, the raw materials contain 34% polydextrose, 33% inulin and 33% oligofructose.

4. The use according to any one of claims 1 to 3, characterized in that: The composite dietary fiber composition is prepared by uniformly mixing polydextrose, inulin and oligofructose raw materials, and then adding a small amount of water vapor or alcohol as a binder for granulation.

5. The use according to claim 1, characterized in that: The method for improving the cooking quality of sea rice includes one or more of the following: (1) Reduce the cooking time of sea rice; (2) Increase the dissolution of cooked sea rice solids; (3) Reduce the hardness, stickiness and chewiness of cooked sea rice while maintaining adhesion, cohesion and elasticity; (4) Inhibiting starch retrogradation and aging of cooked sea rice; (5) Improve the softness of cooked sea rice.

6. The use according to claim 5, characterized in that: The method of improving the softness of cooked sea rice includes influencing the starch structure, protein secondary structure and microstructure of the rice.

7. The use according to claim 1, characterized in that: The composite dietary fiber composition is added to the washed sea rice, mixed evenly, and then the rice is cooked in an electric rice cooker.

8. The use according to claim 7, characterized in that: The added amount of the composite dietary fiber composition is 3-10% of the mass of the sea rice.

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