Method for rapidly preparing instant slow-digesting yellow waxy rice

Abstract

The application discloses a quick preparation method of instant slow-digesting yellow waxy rice, and belongs to the technical field of food processing.The method comprises the following steps: preparing high-pressure homogenized multi-fruit juice, asparagus setaceus water extract freeze-dried powder and liquid extract of liquidambar formosanum leaves; preparing a composite yellow dyeing solution; placing waxy rice in a mesh packaging bag, sealing the mesh packaging bag, and then placing the mesh packaging bag in a dyeing and sealing bag; injecting the composite yellow dyeing solution into the dyeing and sealing bag, and vacuumizing the dyeing and sealing bag; placing the dyeing and sealing bag at room temperature for a certain period of time, and then performing ultrahigh-pressure treatment on the dyeing and sealing bag, and then placing the dyeing and sealing bag at room temperature for a certain period of time; opening the dyeing and sealing bag, taking out the mesh packaging bag, and then draining the excess dyeing solution in the mesh packaging bag; placing the waxy rice in the mesh packaging bag in a high-temperature steaming box, and then placing the high-temperature steaming box in an outer packaging and sealing bag to steam for 40-50 min; taking out the outer packaging and sealing bag after steaming, and immediately vacuumizing and packaging the outer packaging and sealing bag, and then refrigerating. The application shortens the preparation time of the waxy rice and prolongs the storage time of the waxy rice.

Description

Technical Field

[0001] This invention relates to the field of food processing technology. More specifically, this invention relates to a rapid preparation method for ready-to-eat, slow-digesting yellow glutinous rice. Background Technology

[0002] Flowered glutinous rice is a traditional delicacy. It typically comes in seven colors: orange, yellow, blue, green, purple, black, and white. These different colors are achieved by using natural pigments extracted from the flowers, stems, and leaves of various edible plants. Common natural dyes used in flowered glutinous rice include sappanwood, buddleja flower, butterfly pea flower, Nyonya flower, and purslane. Nyonya flower dye is made by mixing buddleja flower and butterfly pea flower in a 1:1 ratio.

[0003] The traditional method for making patterned glutinous rice involves extracting dye from the flowers, stems, and leaves of various plants using hot water. The glutinous rice is then mixed with the dye and soaked for at least 12 hours. After draining the dye, the dyed rice is placed on a steamer lined with gauze and steamed for about 50 minutes to obtain fresh patterned glutinous rice. However, this traditional method has drawbacks: a long preparation time, a short shelf life, and a rapid rise in blood sugar during digestion. Summary of the Invention

[0004] The purpose of this invention is to provide a rapid preparation method for ready-to-eat, slow-digesting yellow glutinous rice. By adding a compound natural dye extract to the glutinous rice, and using a specially designed mesh packaging bag for dyeing, ultra-high pressure, and high-temperature steam treatment, the excellent quality characteristics of the glutinous rice are guaranteed. Compared to the traditional 12-hour production process, the production time is shortened by more than 60%, while simultaneously achieving flexible control over the textural properties of the glutinous rice, reducing the rate of blood glucose rise during digestion, and mitigating the potential adverse effects of microbial growth on the quality of the glutinous rice during storage.

[0005] To achieve these objectives and other advantages of the present invention, a rapid preparation method for ready-to-eat slow-digesting yellow glutinous rice is provided, comprising:

[0006] S1. After washing and removing the pits from the fruit, the fruit is sliced ​​and juiced. The juice is then homogenized under high pressure and stored in an oxygen-free, sealed container. After washing the Osmanthus fragrans, a certain amount of purified water is added and juiced. The juice is then filtered and quick-frozen with liquid nitrogen. The juice is then transferred to a vacuum freeze dryer for freeze-drying to obtain freeze-dried Osmanthus fragrans water extract powder for later use. After washing the Liquidambar formosana leaves, a certain amount of purified water is added and juiced. The leaf residue is then filtered out using a filter screen to obtain a clear Liquidambar formosana leaf extract for later use.

[0007] S2. After washing the Buddleja officinalis flower, extract the Buddleja officinalis flower dye extract. Add a certain amount of tea polyphenols, Liquidambar formosana leaf extract, high-pressure homogenized Duoyi fruit juice and freeze-dried Osmanthus fragrans water extract powder to the Buddleja officinalis flower dye extract to obtain a compound yellow dye solution.

[0008] S3. Place the glutinous rice in a mesh packaging bag and seal it. Then place the mesh packaging bag in a dyeing and sealing bag, inject the compound yellow dye into the dyeing and sealing bag, and vacuum the dyeing and sealing bag.

[0009] S4. After vacuuming, place the dyed and sealed bags at room temperature for a certain period of time. Then place the dyed and sealed bags in a food ultra-high pressure processing equipment for ultra-high pressure processing. After the ultra-high pressure processing is completed, place them at room temperature for a certain period of time to complete the dyeing process of glutinous rice.

[0010] S5. Open the dyeing bag, take out the mesh packaging bag, and drain the excess dye extract from the mesh packaging bag. Then place the glutinous rice in the mesh packaging bag into the high-temperature steaming box. Next, put the high-temperature steaming box into the outer packaging bag and steam together for 40-50 minutes. After steaming, take out the high-temperature steaming box along with the outer packaging bag, vacuum pack immediately, and refrigerate to obtain the finished flower glutinous rice.

[0011] Preferably, in the rapid preparation method of the ready-to-eat slow-digesting yellow glutinous rice, in step S1, after washing the Osmanthus fragrans, 20% of its weight of purified water is added to extract the juice, which is then filtered through a 400-mesh filter. After washing the Liquidambar formosana leaves, 30% of its weight of purified water is added to extract the juice, which is then filtered through a 400-mesh filter.

[0012] Preferably, in the rapid preparation method of the ready-to-eat slow-digesting yellow glutinous rice, in step S2, the Buddleja officinalis dye extract is prepared by hot water extraction at a temperature of 100°C, with a single extraction time of 10-15 minutes and the extraction is performed twice.

[0013] Preferably, in the rapid preparation method of the ready-to-eat slow-digesting yellow glutinous rice, in step S2, the amount of tea polyphenols added is 2% of the total mass of the compound yellow dye solution, the amount of Liquidambar formosana leaf extract added is 2.5% of the total mass of the compound yellow dye solution, after the juice of the fruit is extracted, it is subjected to high-pressure homogenization treatment at 300 MPa, the amount of high-pressure homogenized fruit juice added is 8% of the total mass of the compound yellow dye solution, and the amount of freeze-dried Osmanthus fragrans water extract added is 1.5% of the total mass of the compound yellow dye solution.

[0014] Preferably, in the rapid preparation method of the ready-to-eat slow-digesting yellow glutinous rice, both the mesh packaging bag and the dyed sealing bag are made of polypropylene material, and the mesh of the mesh packaging bag is square with a size of 1.5mm × 1.5mm.

[0015] Preferably, in the rapid preparation method of the ready-to-eat slow-digesting yellow glutinous rice, in step S4, the dyed and sealed bag after vacuuming is placed at room temperature for 30 minutes, and then the dyed and sealed bag is placed in a food ultra-high pressure processing device and processed under ultra-high pressure of 400, 500, or 600 MPa for 15 minutes.

[0016] Preferably, in the rapid preparation method of the ready-to-eat slow-digesting yellow glutinous rice, the outer packaging bag and the high-temperature cooking box are both made of polypropylene material.

[0017] Preferably, in the rapid preparation method of the ready-to-eat slow-digesting yellow glutinous rice, in step S3, a compound yellow dye solution of 2.5 times the weight of the rice is injected into the dyeing sealing bag.

[0018] Preferably, in the rapid preparation method of the ready-to-eat slow-digesting yellow glutinous rice, in step S4, after the ultra-high pressure treatment, the rice is left at room temperature for 2 hours.

[0019] Preferably, in the rapid preparation method of the ready-to-eat slow-digesting yellow glutinous rice, the refrigeration temperature in step S5 is 4°C.

[0020] The present invention has at least the following beneficial effects:

[0021] (1) The preparation method provided by the present invention involves adding a composite yellow dye solution composed of Buddleja officinalis dye extract, tea polyphenols, Liquidambar formosana leaf extract, high-pressure homogenized Duoyi fruit juice and freeze-dried Osmanthus fragrans water extract to glutinous rice, and introducing ultra-high pressure treatment during the dyeing stage before steaming, which greatly shortens the production time of glutinous rice and successfully prepares a ready-to-eat slow-digest glutinous rice with a long storage period.

[0022] (2) In the preparation method provided by the present invention, by adding natural tea polyphenols and intervening in ultra-high pressure treatment, the combined control of the texture characteristics of glutinous rice by "chemical method + physical method" is achieved, so that the glutinous rice produced can better meet the dietary preferences of different groups of people.

[0023] (3) The preparation method provided by the present invention fully explores some functional and processing characteristics of traditional glutinous rice raw materials—Liquidambar formosana leaves, Duoyi juice and Osmanthus fragrans water extract freeze-dried powder. It innovatively selects to introduce the Liquidambar formosana leaf extract obtained in the production process of black glutinous rice, Duoyi juice after high pressure homogenization and Osmanthus fragrans water extract freeze-dried powder into the raw materials for the production of yellow glutinous rice of the present invention, and adds an appropriate amount of natural tea polyphenols to prepare a compound yellow dyeing solution, so that the quality characteristics and digestibility characteristics of the finished yellow glutinous rice are beneficially changed without the addition of artificial synthetic ingredients.

[0024] (4) The specially designed mesh packaging bag in this invention greatly reduces unnecessary direct contact with rice grains during manual operation, simplifies the manual operation process, reduces the potential risk of microbial growth during production and storage, and ensures the safety and hygiene of the finished glutinous rice product to meet the quality inspection standards.

[0025] (5) The glutinous rice product prepared by the present invention can be eaten directly after being heated by microwave or steam, or it can be combined with bean paste, candied fruit, jam and other ingredients to make eight-treasure rice.

[0026] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the mesh packaging bag of the present invention;

[0028] Figure 2 This is a schematic diagram of the dyed sealing bag of the present invention, and the structure of the combination of the mesh packaging bag and the dyed sealing bag;

[0029] Figure 3 This is a schematic diagram of the high-temperature cooking box and the finished product outer packaging sealing bag of the present invention, as well as the structure when the two are used together;

[0030] In the diagram: 1-Open end of mesh packaging bag, 2-Sealing area of ​​mesh packaging bag, 3-Sealing strip of mesh packaging bag, 4-Heat-sealing area of ​​dyed sealing bag, 5-Open end of dyed sealing bag, 6-Open end of outer packaging sealing bag, 7-High temperature retort box, 8-Heat-sealing area of ​​outer packaging sealing bag. Detailed Implementation

[0031] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0032] It should be noted that, unless otherwise specified, the experimental methods described in the following implementation plan are all conventional methods, and the reagents and materials described are all commercially available unless otherwise specified.

[0033] This invention provides a rapid preparation method for ready-to-eat, slow-digesting yellow glutinous rice, comprising:

[0034] S1. After washing and removing the pits from the fruit, the fruit is sliced ​​and juiced. The juice is then homogenized under high pressure and stored in an oxygen-free, sealed container. After washing the Osmanthus fragrans, a certain amount of purified water is added and juiced. The juice is then filtered and quick-frozen with liquid nitrogen. The juice is then transferred to a vacuum freeze dryer for freeze-drying to obtain freeze-dried Osmanthus fragrans water extract powder for later use. After washing the Liquidambar formosana leaves, a certain amount of purified water is added and juiced. The leaf residue is then filtered out using a filter screen to obtain a clear Liquidambar formosana leaf extract for later use.

[0035] S2. After washing the Buddleja officinalis flower, extract the Buddleja officinalis flower dye extract. Add a certain amount of tea polyphenols, Liquidambar formosana leaf extract, high-pressure homogenized Duoyi fruit juice and freeze-dried Osmanthus fragrans water extract powder to the Buddleja officinalis flower dye extract to obtain a compound yellow dye solution.

[0036] S3. Place the glutinous rice in a mesh packaging bag (e.g., Figure 1 Seal the mesh bag in the dyed sealing bag (as shown), then place the mesh bag inside the dyed sealing bag (as shown). Figure 2 (As shown), inject the compound yellow dye solution into the dyeing bag and then evacuate the dyeing bag;

[0037] S4. After vacuuming, place the dyed and sealed bags at room temperature for a certain period of time. Then place the dyed and sealed bags in a food ultra-high pressure processing equipment for ultra-high pressure processing. After the ultra-high pressure processing is completed, place them at room temperature for a certain period of time to complete the dyeing process of glutinous rice.

[0038] S5. Open the dyeing bag, remove the mesh packaging bag, and drain the excess dye extract from the mesh packaging bag. Then place the glutinous rice from the mesh packaging bag into the high-temperature cooking box 7, and then place the high-temperature cooking box into the outer packaging bag (e.g., Figure 3 Steam together (as shown) for 40-50 minutes. After steaming, remove the high-temperature steaming box along with the outer packaging bag and immediately vacuum pack and refrigerate to obtain the finished glutinous rice.

[0039] The mesh packaging bag has an open end 1, a sealing area 2, a sealing strip 3, and the main body of the mesh packaging bag.

[0040] The dyed sealing bag has a dyed sealing bag heat sealing area 4, a dyed sealing bag opening end 5, and a dyed sealing bag body.

[0041] The outer packaging bag has an opening end 6, a heat-sealing area 8, and the body of the outer packaging bag.

[0042] Buddleja officinalis, also known as yellow rice flower, small brocade flower, and chicken bone flower, is a shrub belonging to the genus Buddleja in the family Loganiaceae. Its flower buds and inflorescences are the main dye used in the production of yellow-flowered glutinous rice. The chemical components of Buddleja officinalis mainly consist of flavonoids, phenylethyl alcohols, terpenes, alkaloids, and volatile oils. Related studies have shown that these chemical components have anti-diabetic, antioxidant, antibacterial, and anti-inflammatory effects. The yellow pigment in Buddleja officinalis is the main coloring substance, mainly composed of crocin, crocinic acid, and crocin glycoside. It belongs to the carotenoid pigment class, is not sensitive to light and heat environments, and has good stability.

[0043] Tea polyphenols, mainly including (-)epigallocatechin gallate (EGCG), (-)epigallocatechin (EGC), (-)epicatechin gallate (ECG), and (-)epicatechin (EC), possess a variety of biological functions. In regulating carbohydrate metabolism, tea polyphenols not only reduce the proportion of rapidly digested starch (RDS) and alleviate oxidative stress caused by postprandial hyperglycemia, but also affect the activity of starch-digesting enzymes. This is crucial for slowing the release of glucose from starch or other glycemic carbohydrates. Therefore, as a representative of phenolic compounds, tea polyphenols are beneficial in maintaining glucose homeostasis in the body.

[0044] Liquidambar formosana, a species of tree belonging to the genus Liquidambar in the family Hamamelidaceae, is widely distributed in southern my country. In traditional Chinese medicine, the entire Liquidambar formosana plant can be used medicinally. Liquidambar leaves are an important resource derived from the plant and are one of the raw materials for making black glutinous rice. Modern research shows that Liquidambar leaves contain volatile oils, tannins, flavonoids, shikimic acid, and other active ingredients, possessing numerous effects such as antibacterial, antioxidant, hypoglycemic, anti-inflammatory, and antiseptic properties.

[0045] Osmanthus fragrans is a perennial fern with significant nutritional, health, and medicinal value. In my country, it is mainly distributed in warm temperate and subtropical regions. Components in Osmanthus fragrans possess anti-tumor, anti-cancer, antioxidant, hypoglycemic, antibacterial, and anti-inflammatory properties, indicating great potential for development.

[0046] Duoyi fruit is the fruit of *Castanopsis yunnanensis*, a tropical economic fruit tree belonging to the genus *Castanopsis* in the family Rosaceae. It contains active ingredients such as flavonoids and polyphenols, possessing various bioactive functions including aiding digestion, lowering blood lipids, lowering blood pressure, and lowering blood sugar. Currently, the utilization of Duoyi fruit in food processing mainly involves simple, preliminary processing, producing products such as fruit vinegar beverages, fruit wines, dried fruit, and jams. Its application in the research and development of functional foods is relatively limited, thus indicating significant potential for development and utilization.

[0047] This invention involves washing the flowers of Buddleja officinalis to obtain a dye extract, placing a specially made mesh bag containing glutinous rice into a dyeing and sealing bag, and injecting a certain amount of compound yellow dye into the dyeing and sealing bag. Subsequently, the product is obtained through pre-soaking, ultra-high pressure treatment, dyeing, steaming, and packaging.

[0048] This invention ensures the excellent quality characteristics of glutinous rice by adding a compound natural dye extract to the rice and using a specially designed mesh packaging bag for dyeing, ultra-high pressure, and high-temperature steam treatment. Compared to the traditional 12-hour production process, this method, through the intervention of ultra-high pressure treatment and the addition of a compound yellow dye, shortens the production time by more than 60%, achieves flexible control over the textural properties of the glutinous rice, reduces the rate of blood glucose rise during digestion, and mitigates the potential adverse effects of microbial growth on the quality of the glutinous rice. Simultaneously, the specially designed mesh packaging bag simplifies the operation process, avoids hygiene problems caused by direct manual contact, and helps extend the storage time while ensuring the quality of the glutinous rice.

[0049] The rapid production method of ready-to-eat slow-digesting yellow glutinous rice provided by this invention significantly shortens the production cycle, simplifies the process, inhibits the rate of glucose rise during digestion, reduces the potential risk of microbial growth during production, achieves flexible control over the texture characteristics of the finished product, and has a storage period of more than six months, thus having good application prospects.

[0050] In the rapid preparation method of the ready-to-eat slow-digesting yellow glutinous rice, in step S1, after washing the Osmanthus fragrans, add 20% of the weight of the Osmanthus fragrans to purified water and juice it, then filter it through a 400-mesh filter. After washing the Liquidambar formosana leaves, add 30% of the weight of the Liquidambar formosana leaves to purified water and juice it, then filter it through a 400-mesh filter.

[0051] In the rapid preparation method of the ready-to-eat slow-digesting yellow glutinous rice, in step S2, the Buddleja officinalis dye extract is prepared by hot water extraction at a temperature of 100℃, with a single extraction time of 10-15 min and two extractions.

[0052] In the rapid preparation method of the ready-to-eat slow-digesting yellow glutinous rice, in step S2, the amount of tea polyphenols added is 2% of the total mass of the compound yellow dye solution, the amount of Liquidambar formosana leaf extract added is 2.5% of the total mass of the compound yellow dye solution, after the juice of the fruit is extracted, it is subjected to high-pressure homogenization treatment at 300 MPa, the amount of high-pressure homogenized fruit juice added is 8% of the total mass of the compound yellow dye solution, and the amount of freeze-dried Osmanthus fragrans water extract added is 1.5% of the total mass of the compound yellow dye solution.

[0053] In the rapid preparation method of the ready-to-eat slow-digesting yellow glutinous rice, both the mesh packaging bag and the dyed sealing bag are made of polypropylene material. The mesh of the mesh packaging bag is square and has a size of 1.5mm × 1.5mm.

[0054] In the rapid preparation method of the instant slow-digesting yellow glutinous rice, in step S4, the dyed and sealed bag after vacuuming is placed at room temperature for 30 minutes, and then the dyed and sealed bag is placed in a food ultra-high pressure processing device and processed under ultra-high pressure of 400, 500 and 600 MPa for 15 minutes, which correspond to the three hardness states of the glutinous rice: hard, medium and soft, respectively.

[0055] In the rapid preparation method of the ready-to-eat slow-digesting yellow glutinous rice, the outer packaging bag and the high-temperature cooking box are both made of polypropylene material.

[0056] In the rapid preparation method of the ready-to-eat slow-digesting yellow glutinous rice, in step S3, a compound yellow dye solution with a weight of 2.5 times that of the rice is injected into the dyeing sealing bag.

[0057] In the rapid preparation method of the instant slow-digesting yellow glutinous rice, in step S4, the rice is left to stand at room temperature for 2 hours.

[0058] In the rapid preparation method of the ready-to-eat slow-digesting yellow glutinous rice, the refrigeration temperature in step S5 is 4℃.

[0059] The traditional method for storing glutinous rice is mainly room-temperature air-drying. Specifically, steamed glutinous rice is placed in a bamboo basket to cool to room temperature, then broken into small pieces by hand and continued to air-dry for 6-7 days, rubbing the rice 2-3 times daily during this period to ensure each grain is distinct. After air-drying, the rice is sealed in bags and stored in a cool, dry place, but the storage time is relatively short. The glutinous rice prepared by this invention can be stored for more than six months when refrigerated at 4℃.

[0060] Example 1

[0061] (1) After washing the fruit, remove the pits, slice and juice it. Then, homogenize it under high pressure at 300 MPa and store it in an oxygen-free sealed container. After washing the Osmanthus fragrans, add 20% of its weight in purified water and juice it. Filter out the leaf residue using a 400-mesh filter. Then, quick-freeze the filtered Osmanthus fragrans juice with liquid nitrogen and transfer it to a vacuum freeze dryer for freeze-drying to obtain freeze-dried Osmanthus fragrans water extract powder. After washing the Liquidambar formosana leaves, add 30% of its weight in purified water and juice it. Filter out the leaf residue using a 400-mesh filter to obtain a clear Liquidambar formosana leaf extract.

[0062] (2) Place 80 times the weight of the Buddleja officinalis flower in a clean container, add the washed Buddleja officinalis flower to the above purified water, heat for 15-20 minutes, and then filter out the residue using a 200-mesh filter to obtain dye solution A. Add 2% tea polyphenols, 2.5% Liquidambar formosana leaf extract, 8% of Duoyi fruit juice homogenized under 300MPa pressure and 1.5% freeze-dried Osmanthus fragrans water extract powder to dye solution A to obtain compound yellow dye solution B.

[0063] (3) Place a certain amount of glutinous rice in a specially made mesh packaging bag, then place the mesh packaging bag in a sealed bag, inject about 2.5 times the weight of the glutinous rice into the sealed bag, and then vacuum the sealed bag;

[0064] (4) After vacuuming, place the sealed bag at room temperature for 30 minutes, then perform ultra-high pressure treatment. The treatment pressure is set to 400 MPa and the treatment time is set to 15 minutes. After the ultra-high pressure treatment, place it at room temperature for about 2 hours to further complete the dyeing process of the glutinous rice.

[0065] (5) After dyeing, open the sealed bag, take out the mesh packaging bag containing the dyed yellow glutinous rice, and drain the excess dye extract from the mesh packaging bag. Then place the dyed glutinous rice in the mesh packaging bag into a high-temperature steaming box. Finally, put the high-temperature steaming box containing the glutinous rice into the outer sealed bag and steam together for 40-50 minutes. After steaming, take it out and vacuum pack it immediately. Refrigerate it at 4℃ to cool down and obtain the finished yellow glutinous rice.

[0066] Example 2

[0067] (1) After washing the fruit, remove the pits, slice and juice it. Then, homogenize it under high pressure at 300 MPa and store it in an oxygen-free sealed container. After washing the Osmanthus fragrans, add 20% of its weight in purified water and juice it. Filter out the leaf residue using a 400-mesh filter. Then, quick-freeze the filtered Osmanthus fragrans juice with liquid nitrogen and transfer it to a vacuum freeze dryer for freeze-drying to obtain freeze-dried Osmanthus fragrans water extract powder. After washing the Liquidambar formosana leaves, add 30% of its weight in purified water and juice it. Filter out the leaf residue using a 400-mesh filter to obtain a clear Liquidambar formosana leaf extract.

[0068] (2) Place 80 times the weight of the Buddleja officinalis flower in a clean container, add the washed Buddleja officinalis flower to the above purified water, heat for 15-20 minutes, and then filter out the residue using a 200-mesh filter to obtain dye solution A. Add 2% tea polyphenols, 2.5% Liquidambar formosana leaf extract, 8% of Duoyi fruit juice homogenized under 300MPa pressure and 1.5% freeze-dried Osmanthus fragrans water extract powder to dye solution A to obtain compound yellow dye solution B.

[0069] (3) Place a certain amount of glutinous rice in a specially made mesh packaging bag, then place the mesh packaging bag in a sealed bag, inject about 2.5 times the weight of the glutinous rice into the sealed bag, and then vacuum the sealed bag;

[0070] (4) After vacuuming, place the sealed bag at room temperature for 30 minutes, then perform ultra-high pressure treatment. The treatment pressure is set to 500 MPa and the treatment time is set to 15 minutes. After the ultra-high pressure treatment, place it at room temperature for about 2 hours to further complete the dyeing process of the glutinous rice.

[0071] (5) After dyeing, open the sealed bag, take out the mesh packaging bag containing the dyed yellow glutinous rice, and drain the excess dye extract from the mesh packaging bag. Then place the dyed glutinous rice in the mesh packaging bag into a high-temperature steaming box. Finally, put the high-temperature steaming box containing the glutinous rice into the outer sealed bag and steam together for 40-50 minutes. After steaming, take it out and vacuum pack it immediately. Refrigerate it at 4℃ to cool down and obtain the finished yellow glutinous rice.

[0072] Example 3

[0073] (1) After washing the fruit, remove the pits, slice and juice it. Then, homogenize it under high pressure at 300 MPa and store it in an oxygen-free sealed container. After washing the Osmanthus fragrans, add 20% of its weight in purified water and juice it. Filter out the leaf residue using a 400-mesh filter. Then, quick-freeze the filtered Osmanthus fragrans juice with liquid nitrogen and transfer it to a vacuum freeze dryer for freeze-drying to obtain freeze-dried Osmanthus fragrans water extract powder. After washing the Liquidambar formosana leaves, add 30% of its weight in purified water and juice it. Filter out the leaf residue using a 400-mesh filter to obtain a clear Liquidambar formosana leaf extract.

[0074] (2) Place 80 times the weight of the Buddleja officinalis flower in a clean container, add the washed Buddleja officinalis flower to the above purified water, heat for 15-20 minutes, and then filter out the residue using a 200-mesh filter to obtain dye solution A. Add 2% tea polyphenols, 2.5% Liquidambar formosana leaf extract, 8% of Duoyi fruit juice homogenized under 300MPa pressure and 1.5% freeze-dried Osmanthus fragrans water extract powder to dye solution A to obtain compound yellow dye solution B.

[0075] (3) Place a certain amount of glutinous rice in a specially made mesh packaging bag, then place the mesh packaging bag in a sealed bag, inject about 2.5 times the weight of the glutinous rice into the sealed bag, and then vacuum the sealed bag;

[0076] (4) After vacuuming, place the sealed bag at room temperature for 30 minutes, then perform ultra-high pressure treatment. The treatment pressure is set to 600 MPa and the treatment time is set to 15 minutes. After the ultra-high pressure treatment, place it at room temperature for about 2 hours to further complete the dyeing process of the glutinous rice.

[0077] (5) After dyeing, open the sealed bag, take out the mesh packaging bag containing the dyed yellow glutinous rice, and drain the excess dye extract from the mesh packaging bag. Then place the dyed glutinous rice in the mesh packaging bag into a high-temperature steaming box. Finally, put the high-temperature steaming box containing the glutinous rice into the outer sealed bag and steam together for 40-50 minutes. After steaming, take it out and vacuum pack it immediately. Refrigerate it at 4℃ to cool down and obtain the finished yellow glutinous rice.

[0078] Ultra-high pressure processing is a typical non-thermal processing method. In the processing of glutinous rice, ultra-high pressure promotes the penetration of water in the dye solution into the rice grains. The moisture content inside the rice grains is directly related to the hardness of the cooked rice. The higher the moisture content inside the rice grains, the softer the rice will be after steaming, and vice versa.

[0079] The moisture content inside the rice grains after different treatments was determined by the drying and weighing method. Specifically, after removing excess moisture from the surface of the glutinous rice samples after different treatments with paper towels, the samples were weighed for the first time to obtain the weight of the samples before drying. After weighing, the samples were transferred to desiccators and placed in an oven at 105℃ to dry to constant weight to obtain the weight of the samples after drying. The difference between the weights of the samples before and after drying is the moisture content of the samples. The results are shown in Table 1.

[0080] The moisture distribution in the samples was analyzed using low-field nuclear magnetic resonance (LF-NMR) with a CPMG sequence. The measurement parameters were set to 7.52 μs (P1), 2000 ms (TW), and 14 μs (P2), and a total of 16 scans were performed. The T2 curves were obtained and inverse Laplace transforms were performed using the instrument's auxiliary software. The results are shown in Table 1.

[0081] By combining color difference, texture and sensory evaluation, the quality characteristics of the finished glutinous rice were studied.

[0082] Color difference was measured using a HunterLab colorimeter under a D65 light source and a 10° viewing angle. For each measurement, 20g of finished glutinous rice was spread evenly on the bottom of a quartz cup, and the measured L*, a*, and b* values ​​were recorded. The measurement was repeated three times, and the results are shown in Table 2.

[0083] Texture determination was performed using the P / 36R probe of the TA.XT-Plus texture analyzer. Three whole, plump rice grains were placed radially in the center of the test platform. The test parameters were set as follows: compression deformation 70%, pre-test and post-test speed 5 mm / s, and full texture testing of the finished glutinous rice at a test speed of 1 mm / s. The measurement was repeated six times. The texture results of glutinous rice produced by traditional process and ultra-high pressure process described in this invention are shown in Table 3. The effect of different amounts of tea polyphenols added on the texture characteristics of glutinous rice was studied using a single-factor experimental method. The amount of tea polyphenols added to the composite yellow dye solution was set to 0%, 1%, 2%, and 3%, and the other substances were added according to the optimal addition amount. Ultra-high pressure treatment was not involved in the processing. After the product was completed, the texture determination method described above was used for measurement, and the results are shown in Table 4.

[0084] During the sensory evaluation process, 20 people were randomly selected to taste the flower glutinous rice prepared with different processing parameters, and the sensory evaluation results were given according to the sensory evaluation criteria in Table 5. The sensory evaluation results of the yellow flower glutinous rice obtained according to the traditional process and the production process provided by this invention are shown in Table 6.

[0085] In this invention, the addition amounts of tea polyphenols, Liquidambar formosana leaf extract, high-pressure homogenized Duoyi juice, and freeze-dried Osmanthus fragrans water extract in the composite yellow dye solution were determined using a single-factor experimental method based on the final sensory evaluation results of the glutinous rice. The single-factor experimental scheme is as follows: Under the condition of adding 2% tea polyphenols, 2.5% Liquidambar formosana leaf extract, and 8% high-pressure homogenized Duoyi juice, 0.5%, 1%, 1.5%, 2%, and 2.5% freeze-dried Osmanthus fragrans water extract were added respectively to study the effect of different amounts of freeze-dried Osmanthus fragrans water extract on the sensory characteristics of the glutinous rice and to determine the optimal amount of freeze-dried Osmanthus fragrans water extract. Under the condition of adding 2% tea polyphenols, 2.5% Liquidambar formosana leaf extract, and 1.5% freeze-dried Osmanthus fragrans water extract, 4%, 6%, 8%, 10%, and 12% high-pressure homogenized Duoyi juice were added respectively to study the effect of different high-pressure homogenized Duoyi juice on the sensory characteristics of the glutinous rice. The effects of different amounts of *Ligustrum lucidum* leaf extract on the sensory characteristics of glutinous rice were investigated to determine the optimal amount. Under the conditions of adding 2% tea polyphenols, 8% high-pressure homogenized *Ligustrum lucidum* juice, and 1.5% freeze-dried *Osmanthus fragrans* water extract, the effects of adding 1.5%, 2%, 2.5%, 3%, and 3.5% of *Ligustrum lucidum* leaf extract on the sensory characteristics of glutinous rice were studied to determine the optimal amount. Under the conditions of adding 2.5% *Ligustrum lucidum* leaf extract, 8% high-pressure homogenized *Ligustrum lucidum* juice, and 1.5% freeze-dried *Osmanthus fragrans* water extract, the effects of adding 1%, 1.5%, 2%, 2.5%, and 3% of tea polyphenols on the sensory characteristics of glutinous rice were studied to determine the optimal amount. The single-factor experimental results of the addition amounts of each component in the compound yellow dye solution are shown in Table 7.

[0086] The changes in blood glucose during the digestion of glutinous rice were evaluated by in vitro simulated digestion, which indirectly reflected the inhibitory effect of glutinous rice dyed with compound yellow dye on starch digestive enzymes. The results were presented as the ratio of rapidly digestible starch (RDS), slowly digestible starch (SDS), and resistant starch (RS), as shown in Table 8.

[0087] The specific procedure involves uniformly dispersing 200 mg of lyophilized and ground rice flour sample in a centrifuge tube containing 15 mL of sodium acetate buffer (0.2 mol / L, pH 5.2). Then, six glass bulbs (8 mm in diameter) and a mixed enzyme solution of porcine pancreatin (290 U / mL) and amylase (15 U / mL) are added. The mixture is incubated at 37°C with shaking at 120 rpm / min. At 0, 20, and 120 min, 0.5 mL of the digested sample is mixed with 4 mL of anhydrous ethanol and centrifuged at 4000 × g for 10 min. The supernatant is collected. The glucose content in the supernatant is determined using a glucose assay kit, and the determination is repeated three times. The formulas for calculating the RDS, SDS, and RS content in the finished glutinous rice product are as follows:

[0088]

[0089]

[0090] RS(%) = [1 - (RDS + SDS)]

[0091] In the formula, TS is the sample weight, G0, G 20 and G 120 The glucose content in the hydrolysis products at 0 min, 20 min and 120 min are respectively.

[0092] By employing ultra-high pressure treatment and steaming processes for double sterilization, the quality characteristics of the yellow glutinous rice are well preserved while achieving the expected goal of extending its shelf life without additives. The microbial index determination methods for yellow glutinous rice products during storage refer to the "National Food Safety Standard for Microbiological Examination of Food - Total Colony Count" (GB 4789.2-2022) and "National Food Safety Standard for Microbiological Examination of Food - Coliform Count" (GB 4789.3-2016). The test results are shown in Table 9.

[0093] The method for evaluating the inhibitory activity of phenolic components in lyophilized powders of Duoyi fruit juice and Osmanthus fragrans aqueous extracts against α-glucosidase was as follows: 10–100 μg / mL of phenolic samples extracted from lyophilized powders of Duoyi fruit juice and Osmanthus fragrans aqueous extracts, 50–500 μg / mL of phenolic standards, 4 mM of 4-nitrophenyl-β-D-glucopyranoside (PNPG) solution, and 1 U / mL of α-glucosidase solution were dissolved in phosphate buffer at pH 6.8. 80 μL of the phenolic solution was mixed with 100 μL of PNPG solution and 20 μL of α-glucosidase solution and reacted in a 37°C water bath for 10 min. Phosphate buffer and acarbose solution (0.05–1 μg / mL) were used as negative and positive controls, respectively, instead of the phenolic sample solution. Then, the absorbance of the solution at 405 nm was detected using a microplate reader. The formula for calculating α-glucosidase inhibition is as follows:

[0094]

[0095] Among them OD 对照 and OD 样品 The absorbance values ​​are for the control group and the sample group, respectively. IC 50 The value represents the sample concentration at which the inhibition rate is 50%. The results are shown in Tables 10 and 11. In Table 10, the untreated group refers to the group where, compared to Examples 1, 2, and 3, the Duoyi juice was not subjected to high-pressure homogenization; the HPH-50MPa and HPH-200MPa treated groups refer to the groups where, compared to Examples 1, 2, and 3, only the high-pressure homogenization pressure (50MPa and 200MPa) of the Duoyi juice differed. Based on the final obtained IC... 50 The value was selected as 300 MPa as the condition for high-pressure homogenization of Duoyi juice in this invention.

[0096] Table 1. Moisture content and distribution index of glutinous rice produced by traditional process and this invention

[0097]

[0098]

[0099] Note: "ad" indicates that there is a significant difference (p<0.05) between the same moisture index between the traditional process and the ultra-high pressure process described in this invention.

[0100] As shown in Table 1, the glutinous rice prepared by different embodiments differs to varying degrees in terms of moisture content and distribution compared to the traditional 12h process. This is a very important parameter for obtaining glutinous rice with different textural properties.

[0101] Table 2. Color difference index of cooked glutinous rice produced by traditional process and this invention

[0102] Handling method L* a* b* ΔE Traditional process 12 hours <![CDATA[58.24±0.65 b ]]> <![CDATA[10.58±0.04 a ]]> <![CDATA[68.09±0.12 ab ]]> - Example 1 <![CDATA[58.25±0.05 b ]]> <![CDATA[8.99±0.07 b ]]> <![CDATA[68.35±0.15 a ]]> <![CDATA[1.61±0.61 c ]]> Example 2 <![CDATA[57.20±0.16 c ]]> <![CDATA[8.52±0.16 c ]]> <![CDATA[65.65±0.28 c ]]> <![CDATA[3.36±0.53 b ]]> Example 3 <![CDATA[59.53±0.06 a ]]> <![CDATA[5.90±0.04 d ]]> <![CDATA[62.42±0.30 d ]]> <![CDATA[7.46±0.62 a ]]>

[0103] Note: ΔE was calculated with reference to traditionally made glutinous rice; "ad" indicates that there is a significant difference (p<0.05) between the same color index between the traditional process and the ultra-high pressure process described in this invention.

[0104] As shown in Table 2, the glutinous rice produced by different embodiments differs in color from that produced by the traditional 12h process to some extent, but the difference is almost imperceptible to the human eye.

[0105] Table 3. Texture properties of cooked glutinous rice produced by traditional process and this invention

[0106]

[0107] Note: “ac” indicates that there is a significant difference (p<0.05) between the same texture indexes of the traditional process and the ultra-high pressure process described in this invention.

[0108] As shown in Table 3, the texture characteristics of the glutinous rice prepared in different embodiments are different from those of the traditional 12h process. This difference can better meet the preferences of different groups of people for the texture of rice.

[0109] Table 4. Texture characteristics of cooked glutinous rice with and without added tea polyphenols

[0110]

[0111]

[0112] Note: "ac" indicates that there is a significant difference in the same textural index among different amounts of tea polyphenols (p<0.05).

[0113] As shown in Table 4, compared with glutinous rice without added tea polyphenols, adding a certain amount of tea polyphenols will cause a significant change in the texture of glutinous rice, especially the hardness of the rice. This is the most obvious texture parameter that people perceive during chewing. As the amount of added tea polyphenols increases, the hardness of glutinous rice gradually decreases. This change allows different groups of people to satisfy their preferences for rice texture.

[0114] Table 5. Sensory evaluation criteria for glutinous rice produced using traditional methods and the present invention.

[0115]

[0116] Table 6. Sensory evaluation results of the glutinous rice produced by traditional process and this invention.

[0117]

[0118] Note: “ad” indicates that there is a significant difference (p<0.05) between the same sensory indicators of the traditional process and the ultra-high pressure process described in this invention.

[0119] As shown in Table 6, the glutinous rice prepared in different embodiments showed varying degrees of difference in sensory evaluation results compared to the traditional 12h process. This difference reflects people's preference for the glutinous rice prepared in different embodiments, and therefore the sensory evaluation results are meaningful for this invention.

[0120] Table 7. Effects of the amount of different components added to the compound yellow dye on the sensory properties of glutinous rice.

[0121]

[0122] Note: “ae” indicates that the total score of the same added component is significantly different (p<0.05).

[0123] Table 7 shows the sensory evaluation results of glutinous rice, reflecting the influence of different component addition amounts in the compound yellow dye solution on the sensory characteristics of glutinous rice. This provides an important reference for determining the final addition amounts of different components in the compound yellow dye solution. The addition amounts of different components in the compound yellow dye solution were: 2% tea polyphenols, 2.5% Liquidambar formosana leaf extract, 8% lyophilized fruit juice (homogenized at 300 MPa), and 1.5% freeze-dried Osmanthus fragrans water extract.

[0124] Table 8. In vitro digestion results of yellow glutinous rice products prepared by traditional methods and the method described in this invention.

[0125] Handling method SDS / % RDS / % RS / % Traditional process 12 hours <![CDATA[25.70±0.02 c ]]> <![CDATA[35.46±0.27 a ]]> <![CDATA[41.83±0.28 b ]]> 400MPa <![CDATA[31.38±0.16 b ]]> <![CDATA[26.99±0.10 b ]]> <![CDATA[41.63±0.26 c ]]> 500MPa <![CDATA[32.53±0.02 b ]]> <![CDATA[25.20±0.59 c ]]> <![CDATA[42.26±0.60 a ]]> 600MPa <![CDATA[37.43±0.17 a ]]> <![CDATA[24.79±0.27 c ]]> <![CDATA[37.77±0.43 d ]]>

[0126] Note: SDS represents slow-digesting starch, RDS represents fast-digesting starch, and RS represents resistant starch; "ad" indicates that there is a significant difference in the composition of the same type of starch between the conventional process and the ultra-high pressure process described in this invention (p<0.05).

[0127] As shown in Table 8, the results of in vitro simulated digestion of the glutinous rice prepared according to different embodiments differed to varying degrees from those obtained by the traditional process of 12 hours. This reflects that the glutinous rice prepared according to the embodiments of the present invention can reduce the rate of blood sugar rise to a certain extent during digestion.

[0128] Table 9. Microbiological indicators of yellow glutinous rice products made using traditional methods and the present invention after 180 days of storage.

[0129]

[0130] As shown in Table 9, although the glutinous rice produced by the traditional process of 12h and the different embodiments of the present invention did not deteriorate during storage, affecting food safety, the glutinous rice produced by the different embodiments of the present invention showed better performance in various microbial indicators during storage.

[0131] Table 10. Inhibition of α-glucosidase by phenolic components in Duoyi fruit juice after high-pressure homogenization

[0132] Handling method Free phenol Esterified phenol Conjugated phenol Unprocessed group <![CDATA[44.12±1.04 Aa ]]> <![CDATA[7.27±0.02 Ca ]]> <![CDATA[12.59±0.40 Bb ]]> HPH-50MPa <![CDATA[26.90±0.38 Ab ]]> <![CDATA[5.90±0.35 Cb ]]> <![CDATA[15.27±0.81 Ba ]]> HPH-200MPa <![CDATA[29.68±0.35 Ab ]]> <![CDATA[3.88±0.10 Cc ]]> <![CDATA[12.81±1.12 Bb ]]> HPH-300MPa <![CDATA[16.14±0.64 Ac ]]> <![CDATA[3.39±0.68 Cc ]]> <![CDATA[7.90±0.76 Bc ]]>

[0133] Note: "AC" indicates that there are significant differences in different phenolic components among the same treated Duoyi juice, and "ac" indicates that there are significant differences in the same phenolic components between untreated and high-pressure homogenized Duoyi juice (p<0.05).

[0134] As shown in Table 10, the inhibitory effects of the same phenolic components on α-glucosidase differ between untreated and high-pressure homogenized Duoyi juice. Based on the results of the differences, HPH-300MPa was selected as the optimal treatment condition of this invention.

[0135] Table 11. Inhibition of α-glucosidase by phenolic components in freeze-dried Osmanthus fragrans aqueous extract powder

[0136] Free phenol Esterified phenol Conjugated phenol Freeze-dried powder of Osmanthus fragrans water extract 35.62±0.82 15.27±0.69 10.34±0.31

[0137] As shown in Table 11, the phenolic components in the freeze-dried powder of Osmanthus fragrans water extract have a certain inhibitory effect on α-glucosidase, and therefore it is used as a raw material in this invention.

[0138] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and embodiments shown and described herein.

Claims

1. A rapid preparation method for ready-to-eat, slow-digesting yellow glutinous rice, characterized in that, include: S1. After washing the fruit, remove the pits, slice and juice it. Then, it is homogenized under high pressure and stored in an oxygen-free and sealed environment. After washing the Osmanthus fragrans, a certain amount of purified water was added and juiced. The juice was then filtered, and the filtered Osmanthus fragrans juice was quickly frozen using liquid nitrogen and transferred to a vacuum freeze dryer for freeze drying to obtain freeze-dried Osmanthus fragrans water extract powder for later use. After washing the Liquidambar formosana leaves, a certain amount of purified water was added and juiced. The leaf residue was then filtered out using a filter screen to obtain a clear Liquidambar formosana leaf extract for later use. S2. After washing the Buddleja officinalis flower, extract the Buddleja officinalis flower dye extract. Add a certain amount of tea polyphenols, Liquidambar formosana leaf extract, high-pressure homogenized Duoyi fruit juice and freeze-dried Osmanthus fragrans water extract powder to the Buddleja officinalis flower dye extract to obtain a compound yellow dye solution. S3. Place the glutinous rice in a mesh packaging bag and seal it. Then place the mesh packaging bag in a dyeing and sealing bag, inject the compound yellow dye into the dyeing and sealing bag, and vacuum the dyeing and sealing bag. S4. After vacuuming, place the dyed and sealed bags at room temperature for a certain period of time. Then place the dyed and sealed bags in a food ultra-high pressure processing equipment for ultra-high pressure processing. After the ultra-high pressure processing is completed, place them at room temperature for a certain period of time to complete the dyeing process of glutinous rice. S5. Open the dyeing bag, take out the mesh bag, and drain the excess dye extract from the mesh bag. Then place the glutinous rice in the mesh bag into the high-temperature steaming box. Next, put the high-temperature steaming box into the outer packaging bag and steam together for 40-50 minutes. After steaming, take out the high-temperature steaming box along with the outer packaging bag, vacuum pack immediately, and refrigerate to obtain the finished flower glutinous rice. In S2, the amount of tea polyphenols added is 2% of the total mass of the compound yellow dye solution, the amount of maple leaf extract added is 2.5% of the total mass of the compound yellow dye solution, the amount of *Daucus edulis* juice added after juicing is subjected to high-pressure homogenization at 300 MPa is 8% of the total mass of the compound yellow dye solution, and the amount of freeze-dried Osmanthus fragrans water extract added is 1.5% of the total mass of the compound yellow dye solution. In S4, the dyed and sealed bags after vacuuming are placed at room temperature for 30 minutes, and then placed in a food ultra-high pressure processing device and processed under ultra-high pressure of 400, 500 or 600 MPa for 15 minutes.

2. The rapid preparation method of ready-to-eat slow-digesting yellow glutinous rice as described in claim 1, characterized in that, In S1, after washing the Osmanthus fragrans, add 20% of its weight in purified water to extract the juice, and then filter it through a 400-mesh filter. After washing the Liquidambar formosana leaves, add 30% of its weight in purified water to extract the juice, and then filter it through a 400-mesh filter.

3. The rapid preparation method of ready-to-eat slow-digesting yellow glutinous rice as described in claim 1, characterized in that, In S2, the Buddleja officinalis dye extract was obtained by hot water extraction at 100℃, with a single extraction time of 10-15 min and two extractions.

4. The rapid preparation method of ready-to-eat slow-digesting yellow glutinous rice as described in claim 1, characterized in that, Both the mesh packaging bags and the dyed sealing bags are made of polypropylene material. The mesh of the mesh packaging bags is square, with a size of 1.5mm × 1.5mm.

5. The rapid preparation method of ready-to-eat slow-digesting yellow glutinous rice as described in claim 1, characterized in that, The outer packaging bags and high-temperature retort boxes of the finished product are both made of polypropylene.

6. The rapid preparation method of ready-to-eat slow-digesting yellow glutinous rice as described in claim 1, characterized in that, In step S3, a compound yellow dye solution with a mass of 2.5 times the weight of rice is injected into the dyeing bag.

7. The rapid preparation method of ready-to-eat slow-digesting yellow glutinous rice as described in claim 1, characterized in that, In S4, after the ultra-high pressure treatment is completed, it is left at room temperature for 2 hours.

8. The rapid preparation method of ready-to-eat slow-digesting yellow glutinous rice as described in claim 1, characterized in that, In S5, the refrigeration temperature is 4℃.

Images