Highland barley curing method and application thereof

Abstract

The invention relates to the technical field of food processing, and discloses a highland barley curing method and application thereof.The method comprises the steps that highland barley and water are mixed according to the infiltration proportion for infiltration treatment, and after infiltration treatment, drying treatment is conducted to complete curing of the highland barley; the infiltration ratio is that the weight percentage of the water and the highland barley is equal to the highland barley water absorption rate corresponding to the infiltration treatment time, and the infiltration treatment time is 3-5 hours. According to the highland barley curing method provided by the invention, the loss of nutritional ingredients in the highland barley is reduced, the hardness of highland barley particles is reduced, the chewing resistance is reduced, and the taste and eating quality of the highland barley are improved, the highland barley cured by the method disclosed by the invention can be cooked together with rice, and the cooking adaptability of the highland barley is improved; the eating experience of cooking the highland barley and the rice at the same time is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of food processing, and particularly relates to a method for ripening highland barley and its application. Background Art

[0002] Highland barley belongs to the annual herbaceous plants of the genus Hordeum in the tribe Triticeae of the family Poaceae. It is not only the most dominant food crop on the Qinghai-Tibet Plateau, but also has the component characteristics of "high three and low two", namely high protein, high fiber, high vitamin and low fat, low sugar. It is a high-quality cereal crop and has become an important part of modern healthy diet. However, the texture of highland barley is relatively hard, the cooking time is relatively long, and the cooking adaptability is poor. When preparing highland barley rice, it is very difficult to cook highland barley and rice together at the same time, and the eating experience of cooking highland barley and rice together is poor.

[0003] Ripening refers to the process of improving the performance, stability or quality of a substance through natural or artificial means under certain conditions for a period of time. In food processing, the ripening of grains is the process of changing the structures of components such as starch and protein in grains through physical, chemical or biological methods, so as to improve their edible quality, digestibility and flavor. The core of ripening is the gelatinization of starch, that is, the starch granules absorb water, swell and rupture to form a colloidal structure, making it easier to be decomposed by human digestive enzymes. By pre-treating and ripening highland barley, the cooking adaptability of highland barley can be improved to achieve the effect of cooking highland barley and rice together at the same time. When people prepare highland barley rice, they can heat the pre-ripened highland barley and rice together without additional time adjustment, so as to adapt to the fast pace of modern life. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a method for ripening highland barley and its application, so as to solve the problem of poor cooking adaptability of highland barley, and at the same time improve the quality and nutritional value of the ripened highland barley.

[0005] To achieve the above purpose, the present invention provides the following technical solutions.

[0006] In the first aspect, the present invention provides a method for ripening highland barley, which is to mix highland barley and water according to the infiltration ratio for infiltration treatment, and after the infiltration treatment, perform drying treatment to complete the ripening of highland barley; the infiltration ratio is that the weight percentage of the water to the highland barley is equal to the water absorption rate of highland barley corresponding to the infiltration treatment time, and the infiltration treatment time is 3-5 h, preferably 4 h.

[0007] Further, in some embodiments of the present invention, the infiltration treatment includes primary infiltration and secondary infiltration, and the detailed operations include the following steps:

[0008] Step 1: Mix highland barley and water in a first ratio for a primary soaking treatment. The first ratio is such that the weight percentage of water to highland barley is equal to the water absorption rate of highland barley corresponding to the primary soaking treatment time. The primary soaking treatment time is 3 - 5 h, preferably 4 h. After the primary soaking treatment, perform a drying treatment to obtain primary soaked highland barley.

[0009] Step 2: Mix the primary soaked highland barley and water in a second ratio for a secondary soaking treatment. The second ratio is such that the weight percentage of water to the primary soaked highland barley is equal to the water absorption rate of highland barley corresponding to the secondary soaking treatment time. The secondary soaking treatment time is 3 - 5 h, preferably 4 h. After the secondary soaking treatment, perform a drying treatment to obtain secondary soaked highland barley.

[0010] Through the soaking treatment (control of water addition amount and soaking time), taking the water absorption rate of highland barley as the control standard for the water addition amount during soaking, the present invention precisely controls the contact situation between highland barley and water, enabling the water absorption amount of highland barley during the soaking process to be exactly the added water amount. In this way, it can not only make highland barley fully absorb water and soften its texture, but also enable the water to evenly penetrate into the interior of highland barley, activating the biological enzymes and life activities inside highland barley, providing a good foundation for the subsequent gelatinization of starch. At the same time, compared with soaking, it can also avoid excessive water causing excessive loss of water-soluble nutrients in highland barley. Further, compared with the primary soaking, through two soakings, the present invention enhances the water absorption ability of highland barley, improves the gelatinization degree of highland barley, enhances the adaptability of highland barley in food processing. At the same time, the secondary soaking promotes the uniform distribution of water, can effectively reduce the particle hardness, reduce the chewing resistance, and significantly improve the taste and edible quality of cooked highland barley.

[0011] Preferably, in some embodiments of the present invention, the technical solution for highland barley ripening further includes the step of constructing a dynamic curve of highland barley water absorption, and obtaining the water absorption rate values of highland barley corresponding to different time nodes through the constructed dynamic curve of highland barley water absorption.

[0012] Specifically, the method for constructing the dynamic curve of highland barley water absorption includes the following steps: Take highland barley and soak it in water. Set multiple time nodes to take out the highland barley for weight measurement, and calculate the water absorption rate of highland barley according to formula (Ⅰ). Plot a curve with the water absorption rate of highland barley as the vertical axis and the time node as the horizontal axis, which is the dynamic curve of highland barley water absorption.

[0013] The formula (Ⅰ) is where Wt is the water absorption rate of highland barley, Mt is the mass of highland barley taken out at the set time node, and Mo is the mass of highland barley before soaking.

[0014] Furthermore, the process parameters of the drying treatment are as follows: the drying temperature is 80-100°C, and the drying time is 90-120 min. More preferably, the process parameters of the drying treatment are as follows: the drying time is 120 min at a drying temperature of 80°C or the drying time is 90 min at a drying temperature of 100°C. Under the optimal infiltration conditions, by optimizing the drying temperature and drying time, the present invention can further improve the nutritional quality of the ripened hulless barley.

[0015] Furthermore, in some embodiments of the present invention, the hulless barley variety is preferably Kangding black hulless barley, the water addition for infiltrating the Kangding black hulless barley is 21.05-25.14%, and the infiltration time is 3-5 h; the more preferable water addition is 24.23%, and the infiltration time is 4 h.

[0016] Second, the present invention also provides an application of the above-mentioned hulless barley ripening method in ripened rice products. Specifically, the twice-infiltrated hulless barley can be cooled and vacuum-packed to become a ripened rice product and put on the market. Ripened rice products are a type of cereal product that can be cooked and eaten with short cooking time and low temperature. It has the characteristics of convenience, quickness, easy digestion, and good storage, showing broad prospects in the convenient food market.

[0017] In summary, compared with the prior art, the hulless barley ripening method provided by the present invention reduces the loss of nutrients in hulless barley, reduces the hardness of hulless barley grains, reduces the chewing resistance, improves the taste and edible quality of hulless barley. The hulless barley ripened by the method of the present invention can achieve the effect of being cooked and cooked together with rice, improves the cooking adaptability of hulless barley, and improves the edible experience of cooking hulless barley and rice together. Description of the Drawings

[0018] Figure 1 The hulless barley water absorption dynamic curve constructed for Example 1 of the present invention. Detailed Embodiments

[0019] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to specific embodiments and drawings.

[0020] The materials, instruments, and detection methods used in the following examples are introduced as follows:

[0021] I. Hulless barley variety: Kangding black hulless barley, provided by the Key Laboratory of Agricultural and Rural Miscellaneous Grain Processing.

[0022] II. Main test reagents: See Table 1.

[0023] Table 1. Main materials and reagents

[0024]

[0025] III. Instruments and equipment: See Table 2.

[0026] Table 2. Main Instruments and Equipment

[0027]

[0028] IV. Detection Methods

[0029] 1. Sensory Scoring

[0030] The sensory scoring criteria were modified with reference to GB / T 15682—2008 "Inspection of Cereals and Oils - Sensory Evaluation Method for Cooking and Eating Quality of Paddy and Rice". A scoring panel consisting of 10 people with a food professional background was selected. According to Table 3 (Scoring Criteria Table), scores were given to the color of the cooked highland barley, and the aroma, taste, chewiness, and adhesiveness after cooking with rice for each index, with a full score of 100 points.

[0031] Table 3. Scoring Criteria Table

[0032]

[0033] 2. Content of Basic Nutritional Components

[0034] Determination of moisture content: Refer to GB5009.3 - 2016 "National Food Safety Standard - Determination of Moisture in Foods";

[0035] Determination of fat content: Refer to GB5009.6 - 2016 "National Food Safety Standard - Determination of Fat in Foods";

[0036] Determination of starch content: Refer to GB5009.9 - 2016 "National Food Safety Standard - Determination of Starch in Foods";

[0037] Determination of protein content: Refer to GB5009.5 - 2016 "National Food Safety Standard - Determination of Protein in Foods".

[0038] 3. Texture of Cooked Highland Barley

[0039] After cooking the cooked highland barley with rice (the cooking time is the same as that of rice cooking), three moderately sized and evenly textured highland barley grains were selected and placed on the texture analyzer platform. In the TPA mode, the P36R probe was selected, the pressure was set to 5 g for two - cycle compression, the compression degree was 75%, the pre - test and post - test speeds were 5 mm / min, the compression speed was 1 mm / s, and the interval time was 5 s.

[0040] 4. Gelatinization Degree of Cooked Highland Barley

[0041] Grind the highland barley after slaking and prepare highland barley slaking rice flour, weigh 0.2g dry highland barley slaking rice flour, add in 98mL distilled water, then add 2mL10mol / L KOH solution, and stir gently for 5min. Gained suspension is centrifuged, takes 1mL supernatant, adds 0.4mL0.5mol / L HCl solution to neutralize, and is settled to 10mL with distilled water. Then add 0.1mL iodine reagent (prepared by being dissolved in 100mL water by 1g iodine and 4g potassium iodide), after fully mixing, use spectrophotometer to measure absorbance A1 at 600nm wavelength, with reagent blank as control.

[0042] Take another 0.2g of cooked highland barley rice flour, treat the sample with 95mL of distilled water and 5mL of 10mol / L KOH solution, and neutralize it with 1.0mL of 0.5M HCl solution. The remaining steps are the same as above, and the absorbance A2 is measured.

[0043] The degree of gelatinization was calculated according to formula (II).

[0044] Formula (II) is:

[0045] 5. Total phenol content of cooked highland barley: Determined using a plant total phenol content detection kit.

[0046] 6. β-glucan content of cooked highland barley: The β-glucan content was determined by Megazyme mixed β-glucan detection kit.

[0047] 7. Flavonoid content of cooked highland barley: The total flavonoid content was determined by aluminum salt colorimetric method.

[0048] 8. Reducing sugar content of cooked highland barley: The reducing sugar content was determined by DNS method.

[0049] 9. Intelligent sensory analysis of cooked barley: using electronic tongue and electronic nose for intelligent sensory analysis.

[0050] (1) Electronic tongue program parameters: electrode cleaning 90s; buffer cleaning 120s; buffer cleaning 120s; stabilization 30s; test sample 30s; buffer cleaning 3s; buffer cleaning 3s; aftertaste measurement 30s. Each sample was measured 5 times in a cycle, and the data of the middle three times were used for result analysis. The taste indexes measured by the electronic tongue include sourness, sweetness, bitterness, saltiness, and umami. The performance of the electronic tongue sensor is shown in Table 4.

[0051] Table 4. Electronic tongue sensor performance table

[0052]

[0053]

[0054] (2) Electronic nose detection parameters: cleaning time 90 s; detection time 150 s; carrier gas 500 mL / min. Each sample was repeated 5 times, and the average value of the middle three experiments was taken for calculation. Different electronic nose sensors were used to measure the flavor, and the performance of the electronic nose sensors is shown in Table 5.

[0055] Table 5. Performance table of electronic nose sensors

[0056] Number Name Sensor response characteristics 1 W1C Sensitive to aromatic compounds 2 W5S Sensitive to nitrogen oxides 3 W3C Sensitive to ammonia and aromatic compounds 4 W6S Selective to hydrides 5 W5C Sensitive to alkanes and aromatic compounds 6 W1S Sensitive to methyl groups 7 W1W Sensitive to inorganic sulfides 8 W2S Sensitive to alcohols and some aromatic compounds 9 W2W Sensitive to aromatics and organic sulfides 10 W3S Sensitive to long-chain alkanes

[0057] Example 1: Construction of the water absorption dynamic curve of hulless barley

[0058] Select hulless barley seeds with uniform size and no diseases, place them in distilled water at room temperature, and set multiple time nodes (0 h, 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h) to measure the water absorption of hulless barley. At each time node, the seeds were taken out, the surface moisture was blotted dry with blotting paper and then weighed. The water absorption rate of hulless barley at different time nodes was calculated according to formula (Ⅰ), and then a curve was plotted with the water absorption rate of hulless barley as the vertical axis and the time node as the horizontal axis, which is the water absorption dynamic curve of hulless barley ( Figure 1 ).

[0059]

[0060] Among them, Wt——Water absorption rate of hulless barley;

[0061] Mt——Mass of hulless barley taken out at the set time node;

[0062] Mo——Mass of hulless barley before soaking.

[0063] See Figure 1 , it can be obtained that the water addition percentage (water / hulless barley) of hulless barley soaked for 1 h is 12.1%, for 2 h is 18.42%, for 3 h is 21.05%, and for 4 h is 24.23%. The water addition amount during soaking is controlled according to this ratio in the following examples.

[0064] Figure 1 It reflects the change of the water absorption rate of hulless barley with the soaking time and reveals the dynamic change process of water absorption of hulless barley. From Figure 1 it can be seen that the water absorption rate of hulless barley gradually increases with the increase of soaking time, showing a trend of being fast first and then slow. At the initial stage of soaking, the water absorption rate is fast, indicating that hulless barley has a strong ability to absorb water; between 3 - 5 h, the water absorption rate gradually slows down; after 4 h, the water absorption rate tends to be stable. Since too long soaking time is not suitable for actual production and difficult to meet the application requirements, 3 - 5 h is selected as the soaking treatment time, and 4 h is the optimal soaking treatment time.

[0065] Example 2. Optimization of the soaking time and times of hulless barley

[0066] Take equal amounts of highland barley and carry out the ripening treatment of highland barley according to the test conditions shown in Table 6 below. Then, evaluate the obtained ripened highland barley from aspects such as sensory, texture, and gelatinization degree (see Tables 7 and 8). Finally, it is obtained that "soaking for 4 hours for the first time and soaking for 4 hours for the second time" is the optimal ripening process parameters for highland barley. The ripening treatment process of highland barley is carried out according to the process of "soaking for the first time, drying, soaking for the second time, drying". The drying process parameters are: temperature 100 °C, time 90 min.

[0067] Table 6. Test conditions table for highland barley soaking

[0068]

[0069] Table 7. Sensory scores and gelatinization degrees of ripened highland barley under different soaking conditions

[0070]

[0071]

[0072] Table 8. Texture characteristics of ripened highland barley under different soaking conditions

[0073] Test number Hardness / g Elasticity / mm Chewiness / g Test 1 15483.91±367.91 0.07±0.00 136.57±15.40 Test 2 15372.17±447.34 0.08±0.01 127.26±6.91 Test 3 15661.08±164.77 0.08±0.01 121.75±18.88 Test 4 14886.55±574.69 0.11±0.06 128.76±13.57 Test 5 14543.90±391.50 0.09±0.00 111.84±16.02 Test 6 13886.60±163.54 0.09±0.00 98.27±14.68 Test 7 10717.10±593.99 0.09±0.00 78.85±15.47 Test 8 9845.98±120.97 0.08±0.00 56.53±7.20

[0074] Referring to Table 7, it can be seen that the sensory score and gelatinization degree generally show an upward trend with the extension of the soaking time. When the soaking time for the first time and the second time is relatively short, the score and gelatinization degree are relatively low. However, with the appropriate extension of the soaking time, the score and gelatinization degree gradually increase and finally reach the highest value when soaking for 4 hours for the second time (Test 8). This indicates that Test 8 significantly improves the sensory quality and gelatinization degree of highland barley.

[0075] Table 8 shows that the extension of soaking time gradually reduces the hardness of hulless barley, and it is the lowest when soaked twice for 4 h, indicating that long-term soaking promotes water penetration and softens the cell wall. When soaked once for 1 h and 2 h, water penetration is insufficient and the hardness is relatively high. At 3 h, water enters but is unevenly distributed, and the compact structure leads to a temporary increase in hardness. After 4 h, the water is evenly distributed and the hardness decreases slightly. Secondary soaking further balances the water, makes the structure of hulless barley more evenly softened, and effectively reduces the hardness. The overall change in elasticity is relatively small. Affected by water distribution and protein structure, the protein absorbs insufficient water during short-term soaking and the elasticity is relatively low. As water penetrates, the protein hydration is enhanced and the elasticity is improved. Secondary soaking balances the water, avoids the decrease in elasticity caused by local over-hydration, and at the same time maintains good texture and processing performance. The chewiness decreases overall. The chewiness of the sample soaked once for 1 h is 136.75 g, which drops to 121.75 g at 3 h, and slightly rises to 128.76 g at 4 h. It is the lowest when soaked twice for 4 h, which is 56.53 g, a 58.6% decrease compared with that soaked once for 1 h. It may be that the water mainly concentrates on the surface layer during short-term soaking, resulting in greater chewing resistance. As time prolongs, the water penetrates into the interior, causing the starch to expand, the texture to soften, and the chewiness to decrease. Secondary soaking promotes the even distribution of water, makes the rice grains softer, effectively reduces the chewing resistance, and significantly improves the taste and edible quality of cooked rice.

[0076] Example 3. Comparison between soaking and immersing of hulless barley

[0077] Take equal amounts of hulless barley, process the hulless barley according to the treatment methods shown in Table 9, and then evaluate the results of the processed hulless barley in terms of sensory, basic nutritional components, texture, gelatinization degree, polyphenols, flavonoids, β-glucan content, etc. See Table 10 for details.

[0078] Table 9. Treatment methods of hulless barley

[0079]

[0080] Table 10. Determination results of hulless barley after different treatments

[0081]

[0082] It can be obtained from Table 10 that the sensory score of the 1# treatment group (raw material group) is 61, the sensory score of the 2# treatment group (immersion group) is 73, and the sensory score of the 3# treatment group (soaking group) is 68, indicating that the untreated hulless barley has obvious defects in taste and texture, probably due to uneven water distribution resulting in relatively high hardness of the rice grains; while the immersion process improves the water uniformity of the rice grains, making the texture and taste of the rice grains after cooking better, and the soaking process is not as good as the immersion process in terms of taste and texture uniformity.

[0083] In terms of moisture content, compared with the raw highland barley with 13.49%, after the second infiltration and the second soaking treatments, the moisture contents were reduced to 8.65% and 8.68% respectively, indicating that the combination of infiltration or soaking and drying treatment can effectively reduce the moisture content and improve the storage stability of the product. There was no significant difference in the fat content among different treatments. The fat contents after the second infiltration and the second soaking were 1.78% and 1.58% respectively, slightly lower than 1.80% of the raw highland barley, probably due to the loss of trace water-soluble lipids. The protein content decreased after different treatments. The protein contents after the second infiltration and the second soaking were 10.67% and 10.23% respectively, showing a decrease compared with 11.50% of the raw highland barley. This may be related to the dissolution and loss of some water-soluble proteins during the infiltration or soaking process. The starch content was reduced to 60.2% and 60.5% after the second infiltration and the second soaking respectively, significantly lower than 64.80% of the raw highland barley, indicating that during the water penetration process, some oligosaccharides may dissolve out, resulting in a decrease in the starch content. Through comprehensive analysis, both the second infiltration and the second soaking can lead to a decrease in the moisture, protein and starch contents of the cooked highland barley rice, while the change in the fat content is relatively small. The second infiltration process is superior to the second soaking in terms of maintaining nutritional components, indicating that the infiltration process can effectively reduce the loss of water-soluble nutrients and improve the nutritional quality of the cooked rice.

[0084] In the 1# treatment group, since the raw material was untreated, its internal structure could not be effectively gelatinized, and the gelatinization degree was the lowest; the gelatinization degree of the 3# treatment group was improved, but due to insufficient water absorption uniformity and efficiency, the effect was inferior to that of the 2# treatment group. This shows that the second infiltration treatment can better improve the gelatinization efficiency of highland barley and provide a better raw material basis for subsequent processing.

[0085] In terms of texture characteristics, the raw material had the highest hardness, reaching 18290.24 ± 420.52 g, with a hard texture, which was not conducive to consumption. The secondary infiltration treatment for 4 h significantly reduced the hardness to 9845.98 ± 120.97 g, showing the best softening effect. In contrast, the hardness of the secondary soaking treatment for 4 h was 11937.74 ± 305.24 g. Although it decreased to some extent, it was still higher than that of the secondary infiltration, indicating that the infiltration process could more effectively promote the uniform distribution of moisture inside the rice grains, thereby enhancing the softening effect. The elasticity changed slightly among different treatments, all within the range of 0.08 to 0.10 mm, indicating that the influence of infiltration and soaking on elasticity was relatively limited. However, the secondary infiltration for 4 h could maintain an appropriate elasticity while reducing the hardness, making the texture of the rice grains more stable. The chewiness of the raw material was the highest, reaching 136.19 ± 45.4 g, indicating that untreated highland barley rice required greater chewing force. The secondary infiltration treatment for 4 h significantly reduced the chewiness to 56.53 ± 7.20 g, showing a consistent downward trend with the hardness. The chewiness of the secondary soaking treatment for 4 h was 137.68 ± 14.4 g. Although it decreased compared to the raw material, it was still much higher than that of the secondary infiltration, indicating that the infiltration process had more advantages in reducing chewing resistance. The secondary infiltration treatment for 4 h reduced the hardness and chewiness while maintaining an appropriate elasticity, making the texture of the rice grains more uniform and stable, which was the best process for improving the edible quality of cooked highland barley rice.

[0086] The polyphenol content of the raw material was the highest, reaching 162.97 mg / 100 g, indicating that unprocessed highland barley could retain the most natural polyphenols. After the secondary infiltration treatment for 4 h, the polyphenol content decreased to 130.73 mg / 100 g because some water-soluble polyphenols dissolved into the infiltration liquid. However, the infiltration process could better control the water penetration and reduce the loss of polyphenols. In contrast, after the secondary soaking treatment for 4 h, the polyphenol content decreased to 118.35 mg / 100 g. The soaking process led to the free penetration of water, damaged the cell structure, released more polyphenols, and might activate polyphenol oxidase (PPO) to accelerate degradation. In summary, the secondary infiltration could better retain the polyphenol components of highland barley compared to the soaking process, mainly due to its more effective control of the loss of water-soluble components and better maintenance of cell integrity.

[0087] The flavonoid content of the raw material was the highest, reaching 77.16 mg / 100 g, indicating that unprocessed highland barley could retain more natural flavonoids. Flavonoids have strong antioxidant properties, but the migration, dissolution loss, and oxidative degradation of water during the processing will affect their content. After the secondary infiltration treatment for 4 h, the flavonoid content decreased to 50.01 mg / 100 g, mainly because some flavonoids dissolved and were lost during the infiltration process. The infiltration process could accurately control the water absorption rate, reduce the damage to the cell structure caused by water migration, and effectively retain flavonoids. In contrast, after the secondary soaking treatment for 4 h, the flavonoid content decreased to 44.41 mg / 100 g, indicating that the soaking process caused a more significant loss of flavonoids, which might be related to the free penetration of water and the increase in the activity of oxidase.

[0088] The content of raw material β-glucan is the highest, which is 3.99%, indicating that unprocessed highland barley can better retain its natural dietary fiber. During the processing, β-glucan decreases due to dissolution and loss, enzymatic degradation, and temperature effects. After secondary infiltration for 4 hours, the content drops to 2.96%, indicating that part of the β-glucan enters the aqueous phase due to its water-soluble characteristics. However, the infiltration process can better control the water penetration and reduce the loss. In contrast, the β-glucan content after secondary soaking for 4 hours drops to 2.40%, with more serious loss. This may be because the free penetration of water leads to the dissolution of the cell wall and the loosening of the structure, making β-glucan more easily dissolved. In addition, microbial or enzymatic degradation may occur during the soaking process, further accelerating the degradation of β-glucan. Generally speaking, the loss of β-glucan is greatly affected by its water-soluble characteristics and the water migration rate. The secondary infiltration process can effectively reduce the loss of water-soluble components, better maintain the β-glucan content than secondary soaking, and retain the dietary fiber functional characteristics of highland barley.

[0089] Example 4. Optimization of the drying process after secondary infiltration

[0090] Take equal amounts of highland barley and carry out the ripening treatment according to the process flow of "primary infiltration for 4 hours - drying - secondary infiltration for 4 hours - drying". Change the drying process parameters (drying temperature and time), and detect the measurement indexes (moisture content, sensory score, gelatinization degree, texture) of the ripened highland barley obtained under different drying process parameters, so as to screen out the optimal drying process parameters.

[0091] The experimental design of the drying process parameters is as follows:

[0092] Drying temperature: 80°C, 100°C, 120°C, 140°C, 160°C;

[0093] Drying time: At each drying temperature, three drying times are set, specifically:

[0094] 80°C: 90 min, 120 min, 180 min;

[0095] 100°C: 60 min, 90 min, 120 min;

[0096] 120°C: 50 min, 80 min, 110 min;

[0097] 140°C: 40 min, 60 min, 80 min;

[0098] 160°C: 30 min, 50 min, 70 min.

[0099] Through preliminary temperature-time screening (sensory evaluation, gelatinization degree, texture), the optimal drying time corresponding to each temperature was determined (80°C for 120 min, 100°C for 90 min, 120°C for 80 min, 140°C for 40 min, 160°C for 30 min). Then, based on this, these five parameters were analyzed and compared (sensory evaluation, flavonoid content, polyphenol content, reducing sugar content, β-glucan content, electronic tongue analysis, and electronic nose analysis). The results showed that the sensory quality and texture of the samples treated at 80°C for 120 min and 100°C for 90 min were the best. Subsequently, the determination of nutritional and functional components found that low-temperature drying (80 - 100°C) was more conducive to the retention of polyphenols and flavonoids (up to 230 mg / 100 g and 45 mg / 100 g respectively), while high-temperature and short-time treatment led to their degradation. The β-glucan content was the highest (about 3.1%) at 80°C for 120 min and 100°C for 90 min, and the reducing sugar content reached 482.84 mg / 100 g at 80°C for 120 min, indicating that low-temperature and long-time drying could reduce the degradation of sugars and maintain better nutritional value. Considering comprehensive indicators such as sensory, texture, gelatinization degree, and nutritional and functional components, the optimal drying conditions for hulless barley cooked rice were finally determined to be 80 - 100°C and 90 - 120 min. This process improved the processing efficiency while maximizing the retention of the nutritional and functional characteristics of hulless barley, providing technical support for improving the quality and market competitiveness of hulless barley products.

[0100] In summary, the experimental results of the above embodiments showed that the technical solution of "primary infiltration for 4 h and secondary infiltration for 4 h" could effectively improve the texture of hulless barley rice and simultaneously increase the retention rate of functional components such as polyphenols, flavonoids, and β-glucan. Among them, the polyphenol content after infiltration treatment was 130.73 mg / 100 g, the flavonoid content was 50.01 mg / 100 g, and the β-glucan content was 2.96%, all of which were significantly better than the traditional soaking process. In addition, by further optimizing the drying conditions, the optimal drying process of 80 - 100°C and 90 - 120 min was screened out, enabling the hulless barley cooked rice to maximize the retention of functional components while ensuring sensory quality. Under these conditions, the highest polyphenol content could reach 128.46 mg / 100 g, flavonoid 50.78 mg / 100 g, and β-glucan 3.15%, effectively improving the nutritional value and processing performance of the cooked rice. This optimized process reduced the damage to functional components caused by traditional high-temperature and short-time drying, providing a feasible technical solution for the large-scale production of hulless barley cooked rice.

[0101] The above are only the preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be construed as limiting the present invention, and the protection scope of the present invention should be defined by the scope of the claims. For those of ordinary skill in the art, without departing from the spirit and scope of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as within the protection scope of the present invention.

Claims

1. A highland barley ripening method, characterized in that: The highland barley is mixed with water according to an infiltration ratio for infiltration treatment, and then dried to complete the maturation of the highland barley; the infiltration ratio is that the weight percentage of the water to the highland barley is equal to the water absorption rate of the highland barley corresponding to the infiltration treatment time, and the infiltration treatment time is 3 to 5 hours.

2. The highland barley ripening method according to claim 1, characterized in that: The infiltration process includes primary infiltration and secondary infiltration.

3. The highland barley ripening method according to claim 1, characterized in that: The method also includes the step of constructing a dynamic curve of highland barley water absorption, and obtaining highland barley water absorption rate values ​​corresponding to different time nodes through the constructed dynamic curve of highland barley water absorption.

4. The highland barley ripening method according to claim 1, characterized in that: The process parameters of the drying treatment are: drying temperature is 80-100° C., and drying time is 90-120 min.

5. The highland barley ripening method according to claim 4, characterized in that: The process parameters of the drying treatment are: the drying time is 120 minutes at a drying temperature of 80° C. or the drying time is 90 minutes at a drying temperature of 100° C.

6. The highland barley ripening method according to claim 1, characterized in that: The infiltration treatment time is 4 hours.

7. The highland barley ripening method according to claim 1, characterized in that: The highland barley is Kangding black highland barley, and the infiltration ratio is 21.05-25.14%.

8. The highland barley ripening method according to claim 7, characterized in that: The infiltration ratio was 24.23%.

9. Application of the highland barley ripening method according to any one of claims 1 to 8 in ripening rice products.

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