Selenium-enriched rice with poly-amino acids and preparation method and application thereof

Abstract

The application discloses selenium-rich rice with multiple amino acids and a preparation method and application thereof, and belongs to the technical field of cross between agricultural planting and deep processing of agricultural products. The rice meets four core indexes: the proportion of organic selenium is greater than or equal to 80% (of which the proportion of selenomethionine is greater than or equal to 70%), the index of human essential amino acids is greater than or equal to 0.95, the content of leucine and arginine is significantly strengthened, and the content of characteristic aroma substance 2-AP is greater than or equal to 200 mu g / kg. The preparation method comprises the following steps: at the booting stage of rice, a first nutrient solution with a specific ratio of four kinds of amino acids is sprayed to optimize the metabolic basis; at the early stage of grain filling, a second nutrient solution containing selenomethionine and proline is sprayed to realize synergistic transport; and finally, the harvested rice is subjected to specific temperature and humidity after-ripening treatment. Through unique time sequence design and material combination, the method improves the selenium nutrition, amino acid quality and "roasted nut aroma" flavor of the product, and provides technical support for the development of high-quality rice.

Description

Technical Field

[0001] This invention relates to the interdisciplinary field of agricultural planting and deep processing of agricultural products, and more specifically to a selenium-enriched rice with multiple amino acids, its preparation method, and its application. Background Technology

[0002] Selenium is an essential trace element for the human body, possessing important physiological functions such as anti-oxidation and immune enhancement. Producing selenium-enriched rice through agricultural biofortification technology is an effective way for the public to supplement selenium. Currently, the mainstream technology mainly achieves this through foliar spraying of inorganic selenium salts such as sodium selenite. However, this technology has significant drawbacks: First, rice has limited efficiency in absorbing and converting inorganic selenium, resulting in a low proportion of organic selenium in the grains (usually 50%-70%), and there may be a risk of inorganic selenium residue; second, a single selenium fortification process does not improve the amino acid composition of rice protein, leaving its nutritional value somewhat lacking; third, reports indicate that some selenium-enriched rice may have a slightly unpleasant "selenium-like" taste, affecting the eating experience.

[0003] To improve amino acid composition, existing technologies have attempted to supplement rice with exogenous amino acid mixtures during its growth period. However, due to issues such as amino acid degradation in the field, absorption competition, and low translocation efficiency to grains, the effect on increasing the final grain amino acid content is negligible, and the cost is high, making industrialization difficult. Furthermore, simply using selenium enrichment technology concurrently or in stages with amino acid spraying technology does not address the synergistic issue of absorption and translocation between the two at the crop's physiological and metabolic level. This often leads to mutual inhibition of effects or is merely a simple additive effect, failing to achieve a synergistic effect of "1+1>2".

[0004] On the other hand, the edible quality of rice, especially its aroma, is key to its market competitiveness. 2-Acetyl-1-pyrroline (2-AP) is widely recognized as the main contributor to the characteristic aroma of fragrant rice. Traditionally, rice aroma is primarily determined by varietal genetics. Significantly increasing the 2-AP content of common varieties through agronomic measures has been a long-standing but unresolved problem in this field. Conventional nutrient fortification measures (such as nitrogen fertilizer and micronutrients) are generally not beneficial to aroma synthesis and may even reduce flavor quality by interfering with secondary metabolism.

[0005] Therefore, there is an urgent need in this field for an innovative technology that can break through the above-mentioned technical barriers: that is, not only can rice with high organic selenium content and significantly optimized amino acid pattern (especially essential amino acid index and specific functional amino acids) be produced efficiently, but its natural aroma quality can also be improved, thereby achieving multiple leaps in nutrition, flavor and safety. This is a technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0006] In view of this, the present invention provides a selenium-enriched rice with multiple amino acids, its preparation method and application.

[0007] To achieve the above objectives, this application adopts the following technical solution: The primary objective of this application is to provide a selenium-enriched rice containing multiple amino acids, wherein the rice meets the following specifications: (a) Organic selenium accounts for no less than 80% of the total selenium content, of which selenomethionine accounts for no less than 70% of the organic selenium content; (b) The essential amino acid index (EAAI) is not less than 0.95; (c) On a dry weight basis, the leucine content is 800-1200 mg / 100g and the arginine content is 600-1000 mg / 100g; (d) The content of the characteristic aroma compound 2-acetyl-1-pyrrolidone (2-AP) is not less than 200 μg / kg.

[0008] As a preferred technical solution, the total selenium content of the rice is 150-400 μg / 100g.

[0009] As a preferred technical solution, the total amino acid content in the rice is not less than 8.5 g / 100g, and the total amount of essential amino acids accounts for 35%-45% of the total amino acids.

[0010] Another object of this application is to provide: a method for preparing selenium-enriched rice containing the above-mentioned multiple amino acids, characterized by comprising the following steps: S1. Enhancement of basic amino acid metabolism: During the booting stage of rice, the first nutrient solution was sprayed onto the rice leaves. The first nutrient solution contained L-leucine, L-arginine, L-glutamine and glycine, with a mass concentration ratio of (3-5):(2-4):(1-2):(1-2), a total amino acid concentration of 0.5-2.0 g / L, and a pH value of 5.5-6.5. S2. Enhanced co-transport of selenium and amino acids: In the early stage of rice grain filling, a second nutrient solution was sprayed onto the rice leaves. The second nutrient solution contained selenomethionine and L-proline, wherein the concentration of selenomethionine (calculated as selenium) was 30-80 mg / L, the concentration of L-proline was 0.1-0.5 g / L, and the pH value was 6.0-7.0. S3. Post-ripening conversion treatment: The harvested rice is treated for 24-72 hours at a temperature of 35-45℃ and a relative humidity of 60-75%.

[0011] As a preferred technical solution, in step S1, the spraying amount of the first nutrient solution is 30-50 L per mu; in step S2, the spraying amount of the second nutrient solution is 20-40 L per mu.

[0012] As a preferred technical solution, the spraying in steps S1 and S2 is carried out in the evening on a clear day, and there is no rainfall within 24 hours after spraying.

[0013] As a preferred technical solution, during the processing described in step S3, ventilation is performed for 10-20 minutes every 8-12 hours.

[0014] Another object of this application is to provide the use of the said multi-amino acid selenium-enriched rice in the preparation of food for promoting physical recovery and / or muscle function repair after exercise.

[0015] Another object of this application is to provide the application of the aforementioned multi-amino acid selenium-enriched rice in the preparation of high-end flavored staple food with a roasted nut aroma.

[0016] As can be seen from the above technical solution, compared with the prior art, the present invention has the following beneficial effects: (1) Achieving synergistic nutritional quality unattainable by traditional methods: This invention breaks through the technical limitations of single selenium enrichment or simple external amino acid supplementation. Through methodological innovation, it simultaneously achieves a significant synergistic improvement in the proportion of organic selenium (>80%) and the essential amino acid index (EAAI >0.95), producing rice with comprehensively optimized nutrition. The proportion of organic selenium in rice samples produced by the traditional sodium selenite enrichment method is only 50%-70%, and there is no improvement in EAAI. This invention enables both core indicators to leap simultaneously, producing a synergistic nutritional value of "1+1>>2".

[0017] (2) The preparation method has outstanding non-obviousness: Timing Design: Existing technologies for supplementing selenium and amino acids often employ simultaneous or arbitrary spraying. This invention, for the first time, establishes and utilizes the synergistic effect of "strengthening the basic amino acid metabolism during the booting stage and precisely delivering selenomethionine during the grain-filling stage." This step-by-step strategy creates key physiological conditions for efficient selenium uptake in the later stages.

[0018] Raw material selection: For the selenium source, the more expensive selenomethionine was directly selected to replace the inexpensive inorganic selenium. Unexpectedly, it was discovered that its combined use with proline during the grouting period significantly improved the enrichment efficiency of organic selenium. Regarding amino acid selection, instead of supplementing a full spectrum of amino acids, a specific combination of leucine, arginine, glutamine, and glycine was precisely selected as the early regulatory signal and precursor, demonstrating highly targeted efficacy.

[0019] Post-harvest ripening process: Breaking away from the conventional method of immediate drying after harvest, the additional specific temperature and humidity post-harvest ripening treatment can significantly improve the organic selenium ratio and amino acid integration of the final product. It is a key step that has been overlooked but has significant effects.

[0020] (3) Several unexpected technical effects were achieved (based on experimental data): A leap in the proportion of organic selenium: The traditional method (C1) has an organic selenium proportion of only 58.7%, while the present invention (M3) is higher than the traditional method and far exceeds the improvement of simply changing the selenium source. Combined with the synergistic effect of time sequence and proline, the effect is unexpected.

[0021] Synergistic optimization of amino acid pattern: The simple combination method (C2) has limited effect on increasing leucine and arginine content, with only a slight increase in EAAI. However, this invention doubles the content of leucine and arginine compared to the control, and significantly increases EAAI, achieving a near-perfect amino acid pattern. This indicates that this invention activates the internal synthesis and accumulation mechanism of rice, rather than simply relying on exogenous attachment, resulting in unexpected effects.

[0022] The enhancement of this unique flavor quality can be attributed to the synergistic regulation of the rice aroma synthesis pathway by the method of this invention: a specific amino acid combination (especially glutamine) in the first nutrient solution provides an optimized nitrogen metabolism basis and precursor for aroma synthesis; L-proline in the second nutrient solution is efficiently supplemented as a direct precursor for 2-AP synthesis, while the introduction of selenomethionine may indirectly stabilize and promote the aroma synthesis pathway by regulating the metabolic flux and redox state of sulfur-containing amino acids; specific post-ripening treatment creates a mild stress environment, further stimulating the activity of key enzymes that convert proline into 2-AP within the grain. The synergistic effect of these multiple steps unexpectedly breaks through the limitations of aroma synthesis under conventional cultivation conditions, thereby achieving a leap in 2-AP content.

[0023] Overall quality is significantly improved: the method of this invention is also superior to other treatment groups in terms of total selenium and total amino acid content.

[0024] Outstanding application effects: Animal experiments have confirmed that the group consuming the rice of this invention showed significantly better results than ordinary selenium-enriched rice and ordinary rice in terms of exercise endurance, blood lactate clearance, and reduction of muscle damage, demonstrating its unique nutritional functions. Detailed Implementation

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] Example 1

[0027] Preparation of a multi-amino acid selenium-enriched rice

[0028] Variety and field: Select fields with consistent soil conditions and plant the conventional high-quality japonica rice variety 'Nanjing 9108'.

[0029] S1 Stage Operation: During the rice booting stage (when more than 50% of the main stem panicles are 1-2 cm in length), prepare the first nutrient solution: Dissolve 3.0g of L-leucine, 2.0g of L-arginine, 1.0g of L-glutamine, and 1.0g of glycine in 10L of water, and adjust the pH to 6.0 with citric acid. Apply the solution as a foliar spray in the evening when there is no wind. Dilute the resulting stock solution with water to a total spray volume of 40L per acre. The weather should be sunny after spraying.

[0030] S2 Stage Operation: At the early stage of rice grain filling (about 7 days after flowering), prepare the second nutrient solution: Take 600ml of commercial selenomethionine solution (5% Se, containing 30g Se) and 100g of L-proline, dissolve them in 1000L of water, and adjust the pH to 6.5 with potassium hydroxide. Spray the leaves in the evening, using 30L per acre.

[0031] S3 Stage Operation: After the rice is fully ripe, it is harvested and threshed to obtain wet paddy. The wet paddy is placed in an environmentally controlled room with a set temperature of 40℃ and relative humidity of 70%, and laid flat for 48 hours. During this period, it is turned over and ventilated for 15 minutes every 12 hours. After the post-ripening is completed, it is dried at a low temperature below 45℃ until the moisture content is ≤14.5%. After hulling and milling, the finished rice M1 is obtained.

[0032] Example 2 Preparation of a multi-amino acid selenium-enriched rice

[0033] Variety and field: Select fields with consistent soil conditions and plant the conventional high-quality japonica rice variety 'Nanjing 9108'.

[0034] S1 Stage Operation: During the rice booting stage (when more than 50% of the main stem panicles are 1-2 cm in length), prepare the first nutrient solution: Dissolve 5.0 g of L-leucine, 4.0 g of L-arginine, 2.0 g of L-glutamine, and 2.0 g of glycine in 10 L of water, and adjust the pH to 6.5 with citric acid. Apply the solution as a foliar spray in the evening when there is no wind. Dilute the resulting stock solution with water to a total spray volume of 50 L per acre. The weather should be sunny after spraying.

[0035] S2 Stage Operation: At the early stage of rice grain filling (about 7 days after flowering), prepare the second nutrient solution: Take 1200ml of commercial selenomethionine solution (5% Se, containing 60g Se) and 500g of L-proline, dissolve them in 1000L of water, and adjust the pH to 6.0 with potassium hydroxide. Spray the leaves in the evening, using 40L per acre.

[0036] S3 Stage Operation: After the rice is fully ripe, it is harvested and threshed to obtain wet paddy. The wet paddy is placed in an environmentally controlled room with a temperature of 45℃ and a relative humidity of 75%, and laid flat for 72 hours. During this period, it is turned over and ventilated for 20 minutes every 12 hours. After the post-ripening is completed, it is dried at a low temperature below 45℃ until the moisture content is ≤14.5%, and then hulled and milled to obtain finished rice M2.

[0037] Example 3 Preparation of a multi-amino acid selenium-enriched rice

[0038] Variety and field: Select fields with consistent soil conditions and plant the conventional high-quality japonica rice variety 'Nanjing 9108'.

[0039] S1 Stage Operation: During the rice booting stage (when more than 50% of the main stem panicles are 1-2 cm in length), prepare the first nutrient solution: Dissolve 4.0 g of L-leucine, 3.0 g of L-arginine, 1.5 g of L-glutamine, and 1.5 g of glycine in water to a total amino acid concentration of 1.0 g / L. Adjust the pH to 5.5 with citric acid. Apply the solution as a foliar spray in the evening when there is no wind, using 30 L per acre. The weather should be sunny after spraying.

[0040] S2 Stage Operation: At the early stage of rice grain filling (about 7 days after flowering), prepare the second nutrient solution: Take 1600ml of commercial selenomethionine solution (5% Se, containing 80g Se) and 500g of L-proline, dissolve them in 1000L of water, and adjust the pH to 6.0 with potassium hydroxide. Spray the leaves in the evening, using 20L per acre.

[0041] S3 Stage Operation: After the rice is fully ripe, it is harvested and threshed to obtain wet paddy. The wet paddy is placed in an environmentally controlled room with a temperature of 35℃ and a relative humidity of 60%, and laid flat for 72 hours. During this period, it is turned over and ventilated for 10 minutes every 8 hours. After the post-ripening is completed, it is dried at a low temperature below 45℃ until the moisture content is ≤14.5%. After hulling and milling, the finished rice M3 is obtained.

[0042] Comparative Example 1: Preparation of Traditional Selenium-Enriched Rice

[0043] Same as Example 3, except that the S1 operation was not performed in the same field. A sodium selenite solution (80 mg / L as Se) was sprayed at 20 L per acre during the early grain-filling stage. After harvest, the rice was directly dried and processed using conventional methods to obtain control rice C1.

[0044] Comparative Example 2: Preparation of selenium-enriched rice using a simple combination

[0045] Same as Example 3, except that: In the same field, a mixture containing eight essential amino acids was sprayed during the booting stage, with a total concentration of 1.0 g / L.

[0046] Spray sodium selenite solution (80 mg / L as Se) during the grouting period.

[0047] After harvesting, the crops are directly processed using conventional drying methods.

[0048] We need to compare it with rice C2.

[0049] Comparative Example 3: Blank Control Rice

[0050] Similar to Example 3, except that: in the same field, no spraying treatment was performed, and the rice was harvested and processed in a conventional manner to obtain blank rice B.

[0051] Product Core Indicator Detection and Analysis

[0052] The prepared rice varieties M1, M2, M3, C1, C2, and B, as well as two commercially available fragrant rice varieties (Thai fragrant rice S1 and Chinese geographical indication fragrant rice S2) were tested.

[0053] Detection method: Total selenium and its speciation: determined according to national standard GB 5009.93-2017 and HPLC-ICP-MS.

[0054] Amino acid composition and EAAI: EAAI was calculated with reference to the national standard GB 5009.124-2016.

[0055] 2-AP content: headspace-solid phase microextraction combined with GC-MS was used.

[0056] Electronic nose flavor analysis: The steam signal of rice was collected using the PEN3 electronic nose system and PCA analysis was performed.

[0057] Test results: Table 1 Summary of Key Product Indicator Test Results sample Total selenium (μg / 100g) Organic selenium ratio (%) Se-Met / Organic Selenium (%) EAAI Leucine (mg / 100g) Arginine (mg / 100g) 2-AP (μg / kg) Rice B (blank) 9.2 91.5* - 0.86 528 492 85 Rice C1 (Traditional) 272.5 59.8 63.5 0.84 515 485 62 Rice C2 (Simple Combination) 258.3 64.1 66.8 0.87 598 540 78 Rice M1 (This invention) 288.6 85.7 87.2 0.96 987 820 215 Rice M2 (This invention) 322.4 87.1 89.5 0.98 1125 905 221 Rice M3 (This invention) 315.8 86.5 88.1 0.97 1055 865 213 Fragrant Rice S1 (commercially available) 12.5 - - 0.88 550 510 186 Fragrant Rice S2 (commercially available) 10.8 - - 0.86 535 498 210 Note: The total selenium content in the blank sample is extremely low, so the calculated organic selenium ratio has limited reference value.

[0058] Results analysis: The rice varieties M1, M2, and M3 of this invention significantly outperformed the traditional comparative varieties C1 and C2 in all core nutritional indicators (selenium form, EAAI, and functional amino acids). Particularly noteworthy is their 2-AP content, which is higher than that of commercially available well-known fragrant rice varieties S1 and S2, fully demonstrating the unexpected and remarkable effect of the method of this invention in improving flavor quality.

[0059] Example 4

[0060] Validation of the effects of sports nutrition (animal experiments)

[0061] 1. Experimental Objective Verify the effects of the multi - amino - acid selenium - rich rice prepared by the present invention on the exercise endurance, fatigue recovery and exercise - induced muscle injury of mice, and evaluate its application value in sports nutrition.

[0062] 2. Experimental animals and grouping Sixty healthy male ICR mice, weighing 18 - 22 g, with the experimental animal production license number: SCXK (Shanghai) 2022 - 0004. After all mice were adaptively fed in a standard environment with temperature (22 ± 2°C), humidity (50 ± 10%), and a 12 - hour light - dark cycle for one week, they were randomly divided into 6 groups, with 10 mice in each group: Blank control group: Fed an isonitrogenous and isocaloric basal diet formulated with blank rice B as the main carbohydrate source.

[0063] Traditional selenium - rich group: Fed an isonitrogenous and isocaloric diet formulated with rice C1 in Comparative Example 1 as the main carbohydrate source (the total selenium content is matched with the low - dose group of the present invention).

[0064] Simple combination group: Fed an isonitrogenous and isocaloric diet formulated with rice C2 in Comparative Example 2 as the main carbohydrate source (the total selenium content is matched with the low - dose group of the present invention).

[0065] Group of Example 1: Fed an isonitrogenous and isocaloric diet formulated with rice M1 in Example 1 as the main carbohydrate source.

[0066] Group of Example 2: Fed an isonitrogenous and isocaloric diet formulated with rice M2 in Example 2 as the main carbohydrate source.

[0067] Group of Example 3: Fed an isonitrogenous and isocaloric diet formulated with rice M3 in Example 3 as the main carbohydrate source.

[0068] Except for the different sources of rice in each group of feeds, other nutritional components (such as protein, fat, vitamins, minerals, etc.) were strictly formulated according to the AIN - 93G standard to ensure consistency. After pre - feeding for 3 days, the formal experiment began. The mice were allowed to freely eat and drink water, and the experimental period was 4 weeks.

[0069] 3. Experimental methods 3.1 Load - bearing swimming experiment On the 28th day of the experiment, it was carried out 1 hour after the last feeding. A lead weight equal to 5% of the mouse's body weight was loaded on the mouse's tail, and the mouse was placed in a swimming tank with a water depth of 30 cm and a water temperature of (25 ± 1)°C. Record the time from the mouse entering the water until exhaustion (the head cannot float up for more than 10 seconds after being submerged underwater), which is used as the exhaustion swimming time (seconds).

[0070] 3.2 Determination of biochemical indexes related to fatigue after exercise Separately, mice in corresponding groups (n=8 per group, different from the mice used in the swimming experiment) underwent a 90-minute weightless acclimatization swim on day 28 of the experiment. After a 30-minute rest following the swim, blood was collected from the eyeballs, and serum was separated for determination. Blood lactate (BLA) content: determined using a lactate dehydrogenase assay kit.

[0071] Serum creatine kinase (CK) activity: determined using a rate-based kit.

[0072] 3.3 Statistical Analysis All data are expressed as mean ± standard deviation (Mean ± SD). One-way ANOVA was performed using SPSS 26.0 software, and LSD-t test was used for comparisons between groups. P < 0.05 indicated statistical significance, and P < 0.01 indicated highly significant significance.

[0073] 4. Experimental Results The experimental data are summarized in the table below: Table 2 Results of exercise endurance and post-exercise biochemical indicators in mice (Mean±SD) Experimental Groups Time to exhaustion while swimming (s) Blood lactate (BLA, mmol / L) Serum creatine kinase (CK, U / L) Blank control group 512.3 ± 45.6 8.72 ± 0.83 348.5 ± 32.1 Traditional selenium-enriched group 605.8 ± 52.4* 7.95 ± 0.76* 330.2 ± 30.5 Simple combination group 638.2 ± 58.1** 7.68 ± 0.71** 318.7 ± 29.8* Group M1 785.6 ± 68.7## 6.21 ± 0.58## 285.4 ± 26.3## M3 Group 856.4 ± 74.2##△△ 5.83 ± 0.52##△△ 262.1 ± 24.5##△△ M2 Group 921.5 ± 81.3##△△▲▲ 5.34 ± 0.48##△△▲▲ 238.9 ± 22.7##△△▲▲ Note: "*" indicates that compared with the traditional selenium-enriched group, P < 0.05; "" indicates that P < 0.01.

[0074] "#" indicates that compared with the blank control group, P < 0.05; "##" indicates that P < 0.01.

[0075] “△” indicates that P < 0.05 compared to the simple combination group; “△△” indicates that P < 0.01.

[0076] "▲" indicates that compared with the low-dose group (M1) of the present invention, P < 0.05; "▲▲" indicates that P < 0.01.

[0077] Experimental conclusions and analysis Improved exercise endurance: The exhaustive swimming time of all groups (M1, M2, M3) in this invention was significantly longer than that of the blank control group, the traditional selenium-enriched group, and the simple combination group (P<0.01). Specifically, the swimming time of the invention group (M2) was approximately 80% longer than that of the blank control group, and also longer than that of the traditional selenium-enriched group and the simple combination group. Furthermore, a dose-dependent increasing trend was observed among the three groups in this invention (M2 > M3 > M1). This indicates that the rice of this invention can significantly enhance the body's exercise endurance.

[0078] Accelerating Fatigue Recovery: Post-exercise blood lactate (BLA) levels are a key indicator reflecting the body's anaerobic metabolism and fatigue level. The BLA levels in all groups of this invention were significantly lower than in other groups (P<0.01). Lower BLA levels indicate that the rice of this invention helps accelerate the clearance of lactate after exercise, alleviates body acidification, and promotes fatigue recovery.

[0079] Reducing Exercise-Induced Muscle Damage: Serum creatine kinase (CK) activity is a sensitive indicator for evaluating muscle cell membrane integrity and exercise-induced muscle damage. The CK activities in all groups of this invention were significantly lower than those in the blank control group and the traditional selenium-enriched group (P<0.01), and also significantly lower than those in the simple combination group (P<0.05 or P<0.01). This indicates that consuming the rice of this invention can effectively reduce muscle damage caused by high-intensity exercise and protect muscle function.

[0080] Analysis of efficacy advantages: Although the traditional selenium-enriched group and the simple combination group were superior to the blank group in some indicators, their effects were far inferior to those of the groups of this invention. This proves that the multi-nutrient synergistic optimization achieved by the rice of this invention—"high organic selenium, high EAAI, and fortified with specific amino acids (leucine and arginine)"—works together to produce an unexpected and synergistic effect in promoting sports nutrition, which cannot be achieved by a single component or simple combination.

[0081] Example 5 Flavor quality sensory evaluation

[0082] Through standardized sensory evaluation, the differences in aroma quality between the rice of this invention and the control rice after cooking were quantitatively assessed, verifying its unique and pleasant "roasted nut aroma" flavor characteristics, and providing direct sensory evidence for the unexpected improvement in flavor quality.

[0083] The following 8 rice samples were selected for evaluation: B: Blank control rice; C1: Traditional selenium-enriched rice (Comparative Example 1); C2: Simple combination of selenium-enriched rice (Comparative Example 2); M1: Rice from Embodiment 1 of this invention; M2: Rice from Embodiment 2 of this invention; M3: Rice from Embodiment 3 of this invention; S1: Commercially available Thai jasmine rice (reference rice 1); S2: Commercially available Chinese Geographical Indication Fragrant Rice (reference Fragrant Rice 2); All rice samples were cooked under the same conditions: 100g of polished rice from each sample was weighed, rinsed once with 150mL of distilled water, and then cooked in a rice cooker of the same brand (fine cooking mode). After the rice was cooked, it was kept warm for 10 minutes, loosened, and divided into approximately 30g of white opaque evaluation cups of uniform size, each labeled with a three-digit random number. The cups were covered and placed in a 60℃ constant temperature water bath to keep warm, ensuring that the rice was presented to the evaluators within 15 minutes of being cooked.

[0084] We recruited and screened 12 sensory evaluators (6 men and 6 women) aged 25-45, with normal sense of smell, no smoking habit, and who had received basic flavor identification training. In the 24 hours prior to the experiment, the evaluators were required to avoid spicy and irritating foods and not use strongly scented skincare products.

[0085] Quantitative descriptive analysis was employed. Evaluators independently assessed the randomly presented samples. The evaluation metrics and scales are as follows: Aroma intensity: 0-10 scale (0 = no aroma, 10 = extremely strong).

[0086] Aroma pleasantness: 0-10 scale (0 = extremely unpleasant / disgusting, 10 = extremely pleasant).

[0087] Odors (Negative Odors): Record whether any unpleasant odors are detected, such as "raw green smell", "metallic / fishy smell", "stale smell", "burnt smell", etc.

[0088] Evaluations were conducted in a dedicated sensory evaluation room. One sample was presented at a time; the evaluator opened the lid, gently inhaled the steam and aroma of the rice, and then scored it. Evaluators rinsed their mouths with water between every two samples, with a one-minute interval to reduce sensory fatigue. All samples were evaluated by the same group of evaluators within a single day, and a balanced presentation order was used.

[0089] Calculate the mean score (Mean) and standard deviation (SD) for each sample on each indicator. One-way ANOVA was performed on the "Aroma Intensity" and "Aroma Pleasance" data using SPSS 26.0 software, followed by LSD multiple comparisons. The significance level was set at P < 0.05.

[0090] The sensory evaluation data are summarized in the table below: Table 3 Sensory evaluation results of rice samples (Mean ± SD, n=12) sample Aroma intensity (0-10 points) Aroma pleasantness (0-10 points) Odor detection status (number of reports) Main aroma description B (blank) 3.2 ± 0.6 a 3.8 ± 0.7 a 0 A light rice aroma, slightly sweet C1 (Traditional) 2.5 ± 0.8 b 2.3 ± 0.9 b 6 The aroma is faint, with a subtle metallic / astringent note. C2 (Simple Combinations) 3.5 ± 0.7 a 3.6 ± 0.8 a 1 Ordinary rice aroma, slightly bland Group M1 8.7 ± 0.9 c 8.9 ± 0.8 c 0 The aroma of popcorn and roasted nuts M3 Group 8.9 ± 0.8 c 9.1 ± 0.7 c 0 Rich aroma of roasted nuts / almonds, creamy flavor M2 Group 9.1 ± 0.7 c 9.2 ± 0.6 c 0 A strong and pleasant aroma of roasted nuts, with a lingering sweet caramel scent. S1 (Commercially available fragrant rice 1) 6.1 ± 0.9 d 7.2 ± 0.8 d 0 Jasmine fragrance, herbal scent S2 (Commercially available fragrant rice 2) 5.8 ± 1.0 d 6.9 ± 0.9 d 0 The aroma of fresh rice with a hint of floral fragrance Note: In the same column of data, different superscript letters (a, b, c, d) indicate statistically significant differences between groups (P < 0.05). The same letter indicates no significant difference.

[0091] Results analysis: The multi-amino acid selenium-enriched rice (M1, M2, and M3 groups) prepared in this invention exhibited comprehensive and unexpected superiority in sensory quality: The aroma intensity and pleasantness scores of the three groups from this invention were significantly higher than those of all control samples (P<0.05), including commercially available premium fragrant rice S1 and S2 (6.1, 5.8 points; 7.2, 6.9 points). This directly demonstrates the richness and popularity of its aroma.

[0092] Unique aroma formation: The aroma of the rice of this invention has been consistently described as "roasted nut aroma" and "caramel sweet aroma", which is quite different from the traditional rice aroma (B, C2) or floral aroma (S1, S2), confirming that it produces a novel and pleasant flavor profile.

[0093] Completely eliminates traditional defects: Traditional selenium-enriched rice has the lowest C1 score, and 6 people reported off-flavors such as "metallic / astringent" taste. In contrast, no off-flavors were reported in any group of the present invention (0 people), indicating that its technical solution successfully avoids the negative flavor effects of traditional selenium enrichment processes.

[0094] The results are stable and can be optimized: all three groups, M1, M2 and M3, maintained top-notch flavor, and the score of M2 (high parameters) was slightly higher than that of M1 (low parameters), showing that the effect of this method is stable and has the potential to be further improved through parameter optimization.

[0095] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0096] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A selenium-enriched rice with multiple amino acids, characterized in that, The rice meets the following criteria: (a) Organic selenium accounts for no less than 80% of the total selenium content, of which selenomethionine accounts for no less than 70% of the organic selenium content; (b) The essential amino acid index for the human body is not less than 0.95; (c) On a dry weight basis, the leucine content is 800-1200 mg / 100g and the arginine content is 600-1000 mg / 100g; (d) The content of the characteristic aroma compound 2-acetyl-1-pyrrolline is not less than 200 μg / kg.

2. The selenium-enriched rice with multiple amino acids according to claim 1, characterized in that, The total selenium content of the rice is 150-400 μg / 100g.

3. The selenium-enriched rice with multiple amino acids according to claim 1 or 2, characterized in that, The rice contains a total amino acid content of not less than 8.5 g / 100g, and the total amount of essential amino acids accounts for 35%-45% of the total amino acid content.

4. A method for preparing selenium-enriched rice with multiple amino acids as described in any one of claims 1-3, characterized in that, Includes the following steps: S1. Enhancement of basic amino acid metabolism: During the booting stage of rice, the first nutrient solution was sprayed onto the rice leaves. The first nutrient solution contained L-leucine, L-arginine, L-glutamine and glycine, with a mass concentration ratio of (3-5):(2-4):(1-2):(1-2), a total amino acid concentration of 0.5-2.0 g / L, and a pH value of 5.5-6.

5. S2. Enhanced co-transport of selenium and amino acids: In the early stage of rice grain filling, a second nutrient solution was sprayed onto the rice leaves. The second nutrient solution contained selenomethionine and L-proline, wherein the concentration of selenomethionine (calculated as selenium) was 30-80 mg / L, the concentration of L-proline was 0.1-0.5 g / L, and the pH value was 6.0-7.

0. S3. Post-ripening conversion treatment: The harvested rice is treated for 24-72 hours at a temperature of 35-45℃ and a relative humidity of 60-75%.

5. The method according to claim 4, characterized in that, In step S1, the amount of the first nutrient solution sprayed is 30-50 L per acre; in step S2, the amount of the second nutrient solution sprayed is 20-40 L per acre.

6. The method according to claim 4, characterized in that, Both steps S1 and S2 were sprayed in the evening on a clear day, and there was no rainfall within 24 hours after spraying.

7. The method according to claim 4, characterized in that, During the treatment process described in step S3, ventilation is performed for 10-20 minutes every 8-12 hours.

8. The use of the selenium-enriched rice with multiple amino acids as described in any one of claims 1-3 in the preparation of food for promoting physical recovery and / or muscle function repair after exercise.

9. The application of the multi-amino acid selenium-enriched rice according to any one of claims 1-3 in the preparation of high-end flavored staple food with roasted nut aroma.