A purple sweet potato wine brewed rice cake enriched with anthocyanins and a method of preparing the same

Abstract

The application discloses a kind of anthocyanin-rich purple cabbage wine brewing rice cakes and preparation method thereof.The raw materials of the anthocyanin-rich purple cabbage wine brewing rice cake include purple cabbage powder, wine brewing juice, rice wine lees, glutinous rice powder, low-gluten flour, white granulated sugar, edible oil and water.The mass ratio of the purple cabbage powder, rice wine lees, glutinous rice powder, low-gluten flour and white granulated sugar is 1:0.08-0.2:5-8:1.6-2:0.4-0.85.The mass-volume ratio of the purple cabbage powder and wine brewing juice is 1:1-3 g / mL.The volume ratio of the wine brewing juice, edible oil and water is 1:0.08-0.2:0.2-1.6.The anthocyanin-rich purple cabbage wine brewing rice cake prepared by the application realizes the fortification of functional ingredients such as anthocyanin, improves the shortcomings of traditional rice cake, such as hard taste and single flavor, and endows the rice cake with unique wine brewing aroma.

Description

Technical Field

[0001] This invention relates to the fields of food processing technology and food health technology, specifically to anthocyanin-rich purple cabbage rice cake and its preparation method. Background Technology

[0002] Rice cakes are a traditional grain-based food, made primarily from glutinous rice through processes such as fermentation, kneading, shaping, molding, and cooking. They have a sweet and soft texture and are widely popular. However, traditional rice cakes have a simple ingredient composition, with carbohydrates being the main nutritional component. They lack functional nutrients such as anthocyanins, and the processing lacks methods for preserving and fortifying these functional components, resulting in low nutritional added value.

[0003] Purple cabbage is rich in nutrients such as anthocyanins, vitamins, minerals, dietary fiber, and glucosinolates. Anthocyanins, belonging to the flavonoid branch of polyphenols, exert antioxidant effects by scavenging free radicals and inhibiting oxidase activity, exhibiting strong antioxidant properties. However, the anthocyanins in purple cabbage are relatively unstable and easily decompose and are lost under high-temperature and light-exposed processing conditions, limiting the application of purple cabbage in food processing. Fermented glutinous rice (jiuniang) is a traditional fermented food made from glutinous rice through microbial fermentation. It contains abundant sugars, amino acids, organic acids, and other flavor compounds, giving food a unique mellow and fragrant taste.

[0004] Currently, there are no detailed reports on the technical solutions for combining purple cabbage and fermented rice in rice cake processing. Therefore, developing a purple cabbage and fermented rice cake that combines nutrition and flavor is of great invention significance and value for enriching the variety of rice cakes, improving the nutritional value of rice cakes, and expanding the application scenarios of purple cabbage processing. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide anthocyanin-rich purple cabbage rice cakes and their preparation method. This invention combines purple cabbage with fermented rice to prepare rice cakes, researching and ultimately clarifying the process parameters for each step in preparing anthocyanin-rich purple cabbage rice cakes. The anthocyanin-rich purple cabbage rice cakes prepared by this invention achieve enhanced functional components such as anthocyanins, improving the shortcomings of traditional rice cakes that are too hard and have a monotonous flavor, and endowing the rice cakes with a unique fermented rice aroma.

[0006] To achieve the above objectives, the technical solution designed by the present invention is as follows: This invention provides an anthocyanin-rich purple cabbage rice cake made with fermented rice wine. The ingredients of the anthocyanin-rich purple cabbage rice cake include purple cabbage powder, fermented rice wine juice, rice wine lees, glutinous rice flour, low-gluten flour, white sugar, edible oil and water. The mass ratio of purple cabbage powder, rice wine lees, glutinous rice flour, low-gluten flour, and white sugar is 1:0.08~0.2:5~8:1.6~2:0.4~0.85; The mass-to-volume ratio of purple cabbage powder to fermented rice juice is 1:1~3 g / mL; The volume ratio of the fermented rice juice, edible oil and water is 1:0.08~0.2:0.13~1.6.

[0007] Furthermore, the alcohol content of the fermented rice juice is ≤3% vol, and the total acidity is 0.5~0.8 g / 100 mL.

[0008] Furthermore, the mass ratio of the purple cabbage powder, rice wine lees, glutinous rice flour, low-gluten flour, and white sugar is 1:0.125:6.25:1.875:0.4375; The mass-to-volume ratio of the purple cabbage powder to the fermented rice juice is 1:1.1875 g / mL; The volume ratio of the fermented rice juice, edible oil, and water is 1:0.1053:1.4947.

[0009] The present invention also provides a method for preparing the anthocyanin-rich purple cabbage rice cake, comprising the following steps: (1) Weigh out purple cabbage powder, rice wine juice, rice wine lees, glutinous rice flour, low-gluten flour, white sugar, cooking oil and water according to the above mass ratio, mass-volume ratio and volume ratio; (2) Mix the weighed purple cabbage powder with 1 / 2 of the fermented rice juice and sonicate to obtain purple cabbage fermented rice premix; (3) Mix the weighed glutinous rice flour, low-gluten flour and white sugar evenly, add purple cabbage rice wine premix, the remaining 1 / 2 of the rice wine juice, rice wine lees and water, knead into a dough, and let it rest and rise. (4) Divide the proofed dough into small dough balls and press them into round discs; (5) Preheat the frying pan, brush the top and bottom surfaces of the round cake-shaped dough with cooking oil, fry it, and cool it after frying to obtain anthocyanin-rich purple cabbage rice cake.

[0010] Furthermore, in step (1), the preparation process of purple cabbage powder is as follows: Ⅰ. Slice the purple cabbage, soak it in citric acid solution, take it out, wash it, drain the water, blanch it in boiling water, take it out and put it in an ice water bath to cool it. II. After draining, spread the purple cabbage slices flat and pre-freeze them at a low temperature of -20℃ to -40℃, then freeze-dry them under vacuum to obtain purple cabbage crisps; Ⅲ. Crush the purple cabbage chips and sieve them to obtain purple cabbage powder.

[0011] Furthermore, in step I, the concentration of the citric acid solution is 0.1~0.2 g / 100mL, the soaking time is 15~20 min, and the blanching time is 30~60 s; In step II, the low-temperature pre-freezing time is 11-12 h, the vacuum degree of vacuum freeze-drying is 10-30 Pa, and the vacuum freeze-drying time is 18-24 h. In step III, the sieve mesh size is 80-100 mesh.

[0012] Furthermore, in step (1), the preparation process of the fermented rice juice and rice wine lees is as follows: ① Inoculate glutinous rice with a compound microbial culture and carry out constant temperature fermentation. The compound microbial culture consists of Rhizopus and Saccharomyces cerevisiae. ②After fermentation, the fermented material is filtered through a plate and frame filter to obtain a clear liquid and a solid. The solid is rice wine lees, and the clear liquid is clarified to obtain rice wine juice.

[0013] Furthermore, in step ①, the Rhizopus content is 1×10⁻⁶. 8 ~1×10 9 CFU / g, Rhizopus inoculation amount in glutinous rice was 0.3~0.4% (w / w); Saccharomyces cerevisiae content was 1×10 8 ~1×10 9 The inoculation amount of brewing yeast in glutinous rice was 0.1~0.2% (w / w) CFU / g; the constant temperature fermentation temperature was 28~30℃, and the constant temperature fermentation time was 45~50 h; In step ②, the clarification treatment temperature is 4~6℃ and the clarification treatment time is 8~10 h.

[0014] Furthermore, in step (2), the ultrasonic treatment power is 200~300 W, the ultrasonic treatment temperature is 20~25℃, the ultrasonic treatment frequency is 20~25 kHz, the ultrasonic treatment time is 10~15 min, and the device is stirred once every 3~3.5 min during the ultrasonic treatment. In step (3), the temperature for static fermentation is 25~30℃, and the time for static fermentation is 20~30 min; In step (4), the mass of the small dough ball is 15~20 g, and the thickness of the round cake blank is 0.8~1.2 cm; In step (5), the frying pan is preheated to 160~180℃, and the frying time is 1.5~2.5 min for the upper and lower surfaces respectively.

[0015] Furthermore, in step (2), the ultrasonic treatment power is 220 W, the ultrasonic treatment temperature is 22℃, the ultrasonic treatment frequency is 20 kHz, the ultrasonic treatment time is 12 min, and the device is stirred once every 3 min during the ultrasonic treatment. In step (3), the temperature for resting and proofing is 27°C and the time for resting and proofing is 25 min. In step (4), the mass of the small dough ball is 17 g, and the thickness of the round cake blank is 1 cm; In step (5), the frying pan is preheated to 170°C and the frying time is 2 minutes for each of the upper and lower surfaces.

[0016] The beneficial effects of this invention are: 1. Significant nutritional fortification effect: This invention prepares purple cabbage powder through vacuum freeze-drying and combines it with ultrasonic pretreatment, which effectively preserves the anthocyanins in purple cabbage. The anthocyanin content of the finished rice cake is >2mg / 100g, which solves the problem of anthocyanin loss during the processing of purple cabbage and improves the nutritional added value of the rice cake.

[0017] 2. Significantly improved taste and flavor: This invention uses fermented rice juice to replace part of the water in the dough preparation. The sugars, amino acids, organic acids and other flavor substances in the fermented rice juice give the rice cakes a unique mellow taste. At the same time, the components in the fermented rice juice improve the softness of the dough and improve the traditional rice cakes' hard texture.

[0018] 3. The process is feasible for industrialization: The preparation steps of this invention are clear, the parameters of each step are well-defined and easy to control, and the ultrasonic equipment, molding equipment and frying equipment used are all conventional equipment in the food processing field, which are suitable for large-scale industrial production. The product has both nutrition and flavor and has broad market application prospects. Attached Figure Description

[0019] Figure 1 A flowchart illustrating the preparation process of anthocyanin-rich purple cabbage rice cakes. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to specific embodiments, so that those skilled in the art can understand it.

[0021] Example 1 Preparation of raw materials for anthocyanin-rich purple cabbage rice cakes 1. Preparation of purple cabbage powder (1) Using laboratory vacuum freeze drying method, first select fresh purple cabbage without rot or mold, wash and drain the surface moisture of the purple cabbage, and cut the purple cabbage into thin slices.

[0022] (2) Prepare a citric acid solution of 0.1~0.2 g / 100mL, soak the purple cabbage slices in the citric acid solution for 15~20 min to inhibit polyphenol oxidase activity and prevent browning.

[0023] (3) After soaking, take it out, rinse it once under clean water, drain the water, then put it into boiling water for 30~60 seconds, take it out and quickly put it into an ice water bath to cool to room temperature.

[0024] (4) After draining, spread the purple cabbage slices flat on a tray, put the tray into a low temperature freezer at -20℃~-40℃ for 12 hours, and then use a vacuum freeze dryer to freeze dry in a vacuum environment. Set the vacuum degree to 10~30 Pa and dry for 18~24 hours to obtain purple cabbage crisps.

[0025] (5) Take out the dried purple cabbage chips and crush them. Use an 80-100 mesh standard sieve to screen the purple cabbage powder to ensure uniform particle size and improve the anthocyanin dissolution stability, and obtain purple cabbage powder.

[0026] 2. Preparation of Fermented Rice Juice and Rice Wine Grains (1) The fermented rice juice was prepared by directional fermentation using a compound microbial strain. Xiaogan Zhuhu glutinous rice was used as the fermentation substrate, inoculated with the compound microbial strain, and fermented in a constant temperature incubator at 28-30℃ for 48 h. The compound microbial strain consisted of Angel Yeast food-grade Rhizopus (Rhizopus content 1×10⁻⁶). 8 ~1×10 9 CFU / g) and Angel Yeast Saccharomyces cerevisiae (The yeast count is 1×10⁻⁶) 8 ~1×10 9 The composition was CFU / g, with Rhizopus inoculated at 0.3% (w / w) in glutinous rice and Saccharomyces cerevisiae inoculated at 0.2% (w / w) in glutinous rice.

[0027] (2) After fermentation, the fermented material is filtered through a plate and frame filter (filter membrane pore size 0.45 μm) to obtain clear liquid and solid. The solid is rice wine lees. The clear liquid is treated by low temperature clarification (4℃ standing for 8 h) to obtain rice wine juice. The prepared rice wine juice has an alcohol content ≤3%vol and a total acid (calculated as lactic acid) of 0.5~0.8 g / 100 mL.

[0028] Example 2: Preparation of an anthocyanin-rich purple cabbage rice cake (high-ratio strong aroma type) The ingredients for the anthocyanin-rich purple cabbage rice cake 1 in this embodiment are as follows: 120g purple cabbage powder, 250mL rice wine juice, 10g rice wine lees, 600g glutinous rice flour, 200g low-gluten flour, 80g white sugar, 50mL cooking oil, and 144.4mL water.

[0029] Its preparation method includes the following steps: 1. According to the ingredient ratio in this embodiment, weigh out purple cabbage powder, fermented rice juice, rice wine lees, glutinous rice flour, low-gluten flour, white sugar, cooking oil and water; 2. Pretreatment: Place purple cabbage powder and 1 / 2 of the fermented rice juice (125mL) in an ultrasonic device and ultrasonically treat for 15min at a power of 300W, a temperature of 25℃ and an ultrasonic frequency of 20 kHz, stirring once every 3min during the process, so that the uniformity of the purple cabbage powder and fermented rice juice mixture is ≥90%, reducing the oxidation and degradation of anthocyanins, and obtaining purple cabbage fermented rice premix; 3. Dough preparation: Mix glutinous rice flour, low-gluten flour and white sugar evenly, add purple cabbage rice wine premix, the remaining 1 / 2 of the rice wine juice (125mL), rice wine lees and water, knead into a dough with a moisture content of 35%, let it stand and rise at 30℃ for 30 minutes, and use the components in the rice wine juice to improve the softness of the dough. 4. Shaping: Divide the proofed dough into small dough balls weighing 20g each, and press them into round discs with a thickness of 1.2cm using a pressing device; 5. Cooking: Preheat a frying pan to 180℃, brush the surface of the round cake with cooking oil, place it in the frying pan, and fry for 2.5 minutes on each side until the surface of the cake is golden brown and crispy. Remove it and cool it to room temperature to obtain anthocyanin-rich purple cabbage rice cake 1.

[0030] Example 3: Preparation of an anthocyanin-rich purple cabbage rice cake (balanced classic type) The ingredients for the anthocyanin-rich purple cabbage rice cake 2 in this embodiment are as follows: 80g purple cabbage powder, 200mL rice wine juice, 10g rice wine lees, 500g glutinous rice flour, 150g low-gluten flour, 50g white sugar, 30mL cooking oil, and 70mL water.

[0031] Its preparation method includes the following steps: 1. According to the ingredient ratio in this embodiment, weigh out purple cabbage powder, fermented rice juice, rice wine lees, glutinous rice flour, low-gluten flour, white sugar, cooking oil and water; 2. Pretreatment: Place purple cabbage powder and 1 / 2 of the fermented rice juice (100mL) in an ultrasonic device and ultrasonically treat for 12 minutes at a power of 250W, a temperature of 22℃ and an ultrasonic frequency of 20 kHz, stirring once every 3 minutes during the process, so that the uniformity of the purple cabbage powder and fermented rice juice mixture is ≥90%, reducing the oxidation and degradation of anthocyanins, and obtaining purple cabbage fermented rice premix; 3. Dough preparation: Mix glutinous rice flour, low-gluten flour, and white sugar evenly. Add purple cabbage rice wine premix, the remaining 1 / 2 of the rice wine juice (100mL), rice wine lees, and water. Knead into a dough with a moisture content of 32%. Let it rest and rise at 28℃ for 25 minutes. 4. Shaping: Divide the proofed dough into small dough balls weighing 18g each, and press them into round discs with a thickness of 1.0cm using a pressing device; 5. Cooking: Preheat a frying pan to 170℃, brush the surface of the round cake with cooking oil, place it in the frying pan, and fry for 2 minutes on each side until the surface of the round cake is golden brown and crispy. Remove it and cool it to room temperature to obtain anthocyanin-rich purple cabbage rice cake 2.

[0032] Example 4: Preparation of an anthocyanin-rich purple cabbage rice cake (low-ratio light aroma type) The ingredients for the anthocyanin-rich purple cabbage rice cake 3 in this embodiment are as follows: 50g purple cabbage powder, 150mL rice wine juice, 10g rice wine lees, 400g glutinous rice flour, 100g low-gluten flour, 30g white sugar, 20mL cooking oil, and 20mL water.

[0033] Its preparation method includes the following steps: 1. According to the ingredient ratio in this embodiment, weigh out purple cabbage powder, fermented rice juice, rice wine lees, glutinous rice flour, low-gluten flour, white sugar, cooking oil and water; 2. Pretreatment: Place purple cabbage powder and 1 / 2 of the fermented rice juice (75mL) in an ultrasonic device and ultrasonically treat for 10 minutes at a power of 200W, a temperature of 20℃ and an ultrasonic frequency of 20 kHz, stirring once every 3 minutes during the process, so that the uniformity of the purple cabbage powder and fermented rice juice mixture is ≥90%, reducing the oxidation and degradation of anthocyanins, and obtaining purple cabbage fermented rice premix. 3. Dough preparation: Mix glutinous rice flour, low-gluten flour and white sugar evenly, add purple cabbage rice wine premix, the remaining 1 / 2 of the rice wine juice (75mL), rice wine lees and water, knead into a dough with a moisture content of 30%, and let it rest and rise at 25℃ for 20 minutes. 4. Shaping: Divide the proofed dough into small dough balls weighing 15g each, and press them into round discs with a thickness of 0.8cm using a pressing device; 5. Cooking: Preheat a frying pan to 160℃, brush the surface of the round cake with cooking oil, place it in the frying pan, and fry for 1.5 minutes on each side until the surface of the round cake is golden brown and crispy. Remove it and cool it to room temperature to obtain anthocyanin-rich purple cabbage rice cake 3.

[0034] Example 5: Preparation of an anthocyanin-rich purple cabbage rice cake (high purple cabbage aroma type) The ingredients for the anthocyanin-rich purple cabbage rice cake 4 in this embodiment are as follows: 110g purple cabbage powder, 115mL rice wine juice, 10g rice wine lees, 550g glutinous rice flour, 180g low-gluten flour, 60g white sugar, 10mL cooking oil, and 184mL water.

[0035] Its preparation method includes the following steps: 1. According to the ingredient ratio in this embodiment, weigh out purple cabbage powder, fermented rice juice, rice wine lees, glutinous rice flour, low-gluten flour, white sugar, cooking oil and water; 2. Pretreatment: Place purple cabbage powder and 1 / 2 of the fermented rice juice (57.5mL) in an ultrasonic device and ultrasonically treat for 14 minutes at a power of 280W, a temperature of 24℃ and an ultrasonic frequency of 20 kHz, stirring once every 3 minutes during the process, so that the uniformity of the purple cabbage powder and fermented rice juice mixture is ≥90%, reducing the oxidation and degradation of anthocyanins, and obtaining purple cabbage fermented rice premix; 3. Dough preparation: Mix glutinous rice flour, low-gluten flour and white sugar evenly, add purple cabbage rice wine premix, the remaining 1 / 2 of the rice wine juice (57.5mL), rice wine lees and water, knead into a dough with a moisture content of 34%, and let it stand and rise for 28 minutes at 29℃. 4. Shaping: Divide the proofed dough into small dough balls weighing 19g each, and press them into round discs with a thickness of 1.1cm using a pressing device; 5. Cooking: Preheat a frying pan to 175℃, brush the surface of the round cake with cooking oil, place it in the frying pan, and fry for 2.3 minutes on each side until the surface of the round cake is golden brown and crispy. Remove it and cool it to room temperature to obtain anthocyanin-rich purple cabbage rice cake 4.

[0036] Example 6: Preparation of an anthocyanin-rich purple cabbage rice cake (balanced, slightly sweet type) The ingredients for the anthocyanin-rich purple cabbage rice cake 5 in this embodiment are as follows: 90g purple cabbage powder, 110mL rice wine juice, 10g rice wine lees, 520g glutinous rice flour, 160g low-gluten flour, 40g white sugar, 10mL cooking oil, and 160mL water.

[0037] Its preparation method includes the following steps: 1. According to the ingredient ratio in this embodiment, weigh out purple cabbage powder, fermented rice juice, rice wine lees, glutinous rice flour, low-gluten flour, white sugar, cooking oil and water; 2. Pretreatment: Place purple cabbage powder and 1 / 2 of the fermented rice juice (55mL) in an ultrasonic device and ultrasonically treat for 11 minutes at a power of 230W, a temperature of 22℃ and an ultrasonic frequency of 20 kHz. Stir once every 3 minutes during the treatment to ensure that the uniformity of the purple cabbage powder and fermented rice juice mixture is ≥90%, thereby reducing the oxidation and degradation of anthocyanins and obtaining purple cabbage fermented rice premix. 3. Dough preparation: Mix glutinous rice flour, low-gluten flour and white sugar evenly, add purple cabbage rice wine premix, the remaining 1 / 2 of the rice wine juice (55mL), rice wine lees and water, knead into a dough with a moisture content of 31%, and let it rest and rise at 26℃ for 22 minutes. 4. Shaping: Divide the proofed dough into small dough balls weighing 16g each, and press them into round discs with a thickness of 0.9cm using a pressing device; 5. Cooking: Preheat a frying pan to 165℃, brush the surface of the round cake with cooking oil, place it in the frying pan, and fry for 1.7 minutes on each side until the surface of the cake is golden brown and crispy. Remove it and cool it to room temperature to obtain anthocyanin-rich purple cabbage rice cake.

[0038] Example 7: Preparation of an anthocyanin-rich purple cabbage rice cake (rich and mellow type) The ingredients for the anthocyanin-rich purple cabbage rice cake 6 in this embodiment are as follows: 85g purple cabbage powder, 120mL rice wine juice, 10g rice wine lees, 580g glutinous rice flour, 170g low-gluten flour, 70g white sugar, 10mL cooking oil, and 184.4mL water.

[0039] Its preparation method includes the following steps: 1. According to the ingredient ratio in this embodiment, weigh out purple cabbage powder, fermented rice juice, rice wine lees, glutinous rice flour, low-gluten flour, white sugar, cooking oil and water; 2. Pretreatment: Place purple cabbage powder and 1 / 2 of the fermented rice juice (60mL) in an ultrasonic device and ultrasonically treat for 15min at a power of 290W, a temperature of 25℃ and an ultrasonic frequency of 20 kHz, stirring once every 3min during the process, so that the uniformity of the purple cabbage powder and fermented rice juice mixture is ≥90%, reducing the oxidation and degradation of anthocyanins, and obtaining purple cabbage fermented rice premix. 3. Dough preparation: Mix glutinous rice flour, low-gluten flour and white sugar evenly, add purple cabbage rice wine premix, the remaining 1 / 2 of the rice wine juice (60mL), rice wine lees and water, knead into a dough with a moisture content of 35%, and let it stand and rise for 30 minutes at 30℃. 4. Shaping: Divide the proofed dough into small dough balls weighing 20g each, and press them into round discs with a thickness of 1.2cm using a pressing device; 5. Cooking: Preheat the frying pan to 180℃, brush the surface of the round cake with cooking oil, place it in the frying pan, and fry for 2.5 minutes on each side until the surface of the round cake is golden brown and crispy. Remove it and cool it to room temperature to obtain anthocyanin-rich purple cabbage rice cake.

[0040] Example 8: Preparation of an anthocyanin-rich purple cabbage rice cake (crispy and low-fat type) The ingredients for the anthocyanin-rich purple cabbage rice cake 7 in this embodiment are as follows: 80g purple cabbage powder, 95mL rice wine juice, 10g rice wine lees, 500g glutinous rice flour, 150g low-gluten flour, 35g white sugar, 10mL cooking oil, and 142mL water.

[0041] Its preparation method includes the following steps: 1. According to the ingredient ratio in this embodiment, weigh out purple cabbage powder, fermented rice juice, rice wine lees, glutinous rice flour, low-gluten flour, white sugar, cooking oil and water; 2. Pretreatment: Place purple cabbage powder and 1 / 2 of the fermented rice juice (47.5mL) in an ultrasonic device and ultrasonically treat for 12 minutes at a power of 220W, a temperature of 22℃ and an ultrasonic frequency of 20 kHz, stirring once every 3 minutes during the process, so that the uniformity of the purple cabbage powder and fermented rice juice mixture is ≥90%, reducing the oxidation and degradation of anthocyanins, and obtaining purple cabbage fermented rice premix; 3. Dough preparation: Mix glutinous rice flour, low-gluten flour and white sugar evenly, add purple cabbage rice wine premix, the remaining 1 / 2 of the rice wine juice (47.5mL), rice wine lees and water, knead into a dough with a moisture content of 32%, and let it rest and rise at 27℃ for 25 minutes. 4. Shaping: Divide the proofed dough into small dough balls weighing 17g each, and press them into round discs with a thickness of 1.0cm using a pressing device; 5. Cooking: Preheat the frying pan to 170℃, brush the surface of the round cake with cooking oil, place it in the frying pan, and fry for 2.0 minutes on each side until the surface of the round cake is golden brown and crispy. Remove it and cool it to room temperature to obtain anthocyanin-rich purple cabbage rice cake 7.

[0042] Comparative Example 1: Preparation of Purple Cabbage Rice Cake D1 Rice cakes made using traditional methods, without the addition of purple cabbage powder, were prepared using the same raw material ratios and preparation steps as in Example 2, resulting in purple cabbage rice cake D1. Testing revealed that the rice cakes obtained in the comparative example did not contain anthocyanins, had a hard texture, and a monotonous flavor, showing significant differences in nutritional composition, texture, and flavor compared to the anthocyanin-rich purple cabbage rice cakes prepared using the method of this invention.

[0043] Performance testing The anthocyanin-rich purple cabbage rice cakes 1-7 prepared in Examples 2-8 were subjected to multi-dimensional performance tests, including anthocyanin content, moisture content, and sensory quality. The results are shown in Table 1.

[0044] Table 1. Physicochemical and sensory test results of anthocyanin-rich purple cabbage rice cakes. Note: ND indicates not detected.

[0045] Testing and calculations revealed that the anthocyanin-rich purple cabbage rice cake 1 has an anthocyanin content of 2.09 mg / 100g, a moisture content of 32.1%, a hardness of 1210, and an elasticity of 0.88. It has a soft and full-bodied texture, with a high degree of integration between the rich aroma of fermented rice and the flavor of purple cabbage. The anthocyanin-rich purple cabbage rice cake 2 has an anthocyanin content of 2.37 mg / 100g, a moisture content of 31.8%, a hardness of 1180, and an elasticity of 0.89. It has a soft and crisp texture, with a rich aroma of fermented rice and a subtle fragrance of purple cabbage. The anthocyanin-rich purple cabbage rice cake 3 has an anthocyanin content of 2.12 mg / 100g, a moisture content of 32.5%, a hardness of 1200, and an elasticity of 0.87. It has a crisp texture with a sweet fermented rice flavor and a refreshing aroma of purple cabbage. Anthocyanin-rich purple cabbage rice cake 4 has an anthocyanin content of 2.61 mg / 100g, a moisture content of 31.5%, a hardness of 1150, and an elasticity of 0.90. It has a rich purple cabbage flavor, a mellow aroma of fermented rice, and a soft yet chewy texture. Anthocyanin-rich purple cabbage rice cake 5 has an anthocyanin content of 3.13 mg / 100g, a moisture content of 30.9%, a hardness of 1080, and an elasticity of 0.91. It has a balanced flavor, a moderate sweetness, and a harmonious blend of fermented rice and purple cabbage flavors. Anthocyanin-rich purple cabbage rice cake 6 has an anthocyanin content of 2.48 mg / 100g, a moisture content of 31.7%, a hardness of 1160, and an elasticity of 0.89. It has a rich and intense fermented rice flavor, with purple cabbage as a secondary aroma, and a soft and creamy texture. Anthocyanin-rich purple cabbage rice cake 7 has an anthocyanin content of 6.26 mg / 100g, a moisture content of 30.2%, a hardness of 950, an elasticity of 0.93, and low fat content. It has an exceptionally crisp texture, and the flavors of the fermented rice and purple cabbage are refreshing and not greasy. The total sensory evaluation score for all examples was above 85 points, with anthocyanin-rich purple cabbage rice cake 7 achieving the highest score (93 points). Its blend of the rich aroma of fermented rice and the delicate fragrance of purple cabbage was optimal, with a crispy exterior and soft interior, a moderate sweetness, and no sourness or astringency. The flavors and textures of anthocyanin-rich purple cabbage rice cakes 1-6 were also superior to traditional rice cakes.

[0046] As shown in Table 1, the properties of the anthocyanin-rich purple cabbage rice cakes prepared in each embodiment differ significantly. The relationship between the anthocyanin content and the raw material ratio is discussed below: Firstly, purple cabbage powder is the primary source of anthocyanins in the finished product, providing a basic substrate for the functional components of rice cakes. In Example 1, the highest amount of purple cabbage powder was used, but due to poor compatibility with the pH and moisture conditions of the formula, anthocyanins suffered severe oxidative degradation during processing, resulting in a final anthocyanin content of only 2.09 mg / 100g. In Example 7, the amount of purple cabbage powder added was moderate, and the overall formula components were highly compatible. The weakly acidic environment created by fermentation and the low moisture conditions significantly inhibited anthocyanin decomposition and loss, resulting in a significantly improved anthocyanin retention rate and a detected content of 6.26 mg / 100g, far exceeding the other samples. Therefore, the anthocyanin content of the finished product is not solely determined by the amount of purple cabbage powder added, but rather by the combined effect of the raw material ratio and the stable environment of the system. Optimizing the overall compatibility of the compound formula and simultaneously improving the supply and retention rate of anthocyanin raw materials are the core keys to enhancing the functionality of rice cakes.

[0047] Secondly, the amount of fermented rice used and the control of moisture content have a synergistic protective effect on the stability of anthocyanins. When the amount of purple cabbage powder added is similar, the anthocyanin retention rate of purple cabbage fermented rice cake 7 is higher. This is related to the weakly acidic environment (pH 4.0~5.0) and low moisture content (30.2%) provided by the fermented rice in its raw material ratio, which can effectively inhibit the degradation and hydrolysis of anthocyanins and improve their stability.

[0048] Then, the fermented rice system can significantly improve the textural properties of rice cakes, reducing product hardness and increasing elasticity. Compared with the comparative example, the rice cakes in each embodiment of the present invention show significantly reduced hardness and significantly improved elasticity, indicating that the organic acids, sugars and small molecules in the fermented rice juice and rice wine lees can soften the starch structure, reduce dough hardness, and enhance the fluffiness and resilience of the rice cakes, making the product softer and chewier, effectively solving the problem of traditional rice cakes being too hard and lacking elasticity.

[0049] Finally, the ingredient ratio must balance functional enhancement and sensory quality. As the proportion of purple cabbage powder increased, the anthocyanin content and total sensory evaluation score of the rice cake increased simultaneously. The anthocyanin-rich purple cabbage rice cake 7 had the highest sensory score (93 points) and anthocyanin content, indicating that the optimal ratio of the present invention achieved a synergistic improvement in functional enhancement and eating quality, avoiding flavor defects caused by solely pursuing functional components.

[0050] In summary, by optimizing the proportions of raw materials such as the amount of purple cabbage powder, the amount of rice wine, and the control of moisture content, the content and stability of anthocyanins in rice cakes can be significantly improved. At the same time, the sensory quality of the product can be improved, which solves the defects of traditional rice cakes that are hard in texture and have a single flavor. This provides a reliable formula basis for the industrial production of anthocyanin-rich rice cakes.

[0051] All other parts not described in detail are existing technologies. Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A purple cabbage rice cake rich in anthocyanins, characterized in that: The ingredients of the anthocyanin-rich purple cabbage rice cake include purple cabbage powder, rice wine juice, rice wine lees, glutinous rice flour, low-gluten flour, white sugar, cooking oil and water; The mass ratio of purple cabbage powder, rice wine lees, glutinous rice flour, low-gluten flour, and white sugar is 1:0.08~0.2:5~8:1.6~2:0.4~0.85; The mass-to-volume ratio of purple cabbage powder to fermented rice juice is 1:1~3 g / mL; The volume ratio of the fermented rice juice, edible oil and water is 1:0.08~0.2:0.13~1.

6.

2. The anthocyanin-rich purple cabbage rice cake according to claim 1, characterized in that: The alcohol content of the fermented rice juice is ≤3% vol, and the total acidity is 0.5~0.8 g / 100 mL.

3. The anthocyanin-rich purple cabbage rice cake according to claim 1, characterized in that: The mass ratio of purple cabbage powder, rice wine lees, glutinous rice flour, low-gluten flour, and white sugar is 1:0.125:6.25:1.875:0.4375; The mass-to-volume ratio of the purple cabbage powder to the fermented rice juice is 1:1.1875 g / mL; The volume ratio of the fermented rice juice, edible oil, and water is 1:0.1053:1.4947.

4. A method for preparing anthocyanin-rich purple cabbage rice cake according to any one of claims 1 to 3, characterized in that: Includes the following steps: (1) Weigh out purple cabbage powder, rice wine juice, rice wine lees, glutinous rice flour, low-gluten flour, white sugar, cooking oil and water according to the above mass ratio, mass-volume ratio and volume ratio; (2) Mix the weighed purple cabbage powder with 1 / 2 of the fermented rice juice and sonicate to obtain purple cabbage fermented rice premix; (3) Mix the weighed glutinous rice flour, low-gluten flour and white sugar evenly, add purple cabbage rice wine premix, the remaining 1 / 2 of the rice wine juice, rice wine lees and water, knead into a dough, and let it rest and rise. (4) Divide the proofed dough into small dough balls and press them into round discs; (5) Preheat the frying pan, brush the top and bottom surfaces of the round cake-shaped dough with cooking oil, fry it, and cool it after frying to obtain anthocyanin-rich purple cabbage rice cake.

5. The preparation method according to claim 4, characterized in that: In step (1), the preparation process of purple cabbage powder is as follows: Ⅰ. Slice the purple cabbage, soak it in citric acid solution, take it out, wash it, drain the water, blanch it in boiling water, take it out and put it in an ice water bath to cool it. II. After draining, spread the purple cabbage slices flat and pre-freeze them at a low temperature of -20℃ to -40℃, then freeze-dry them under vacuum to obtain purple cabbage crisps; Ⅲ. Crush the purple cabbage chips and sieve them to obtain purple cabbage powder.

6. The preparation method according to claim 5, characterized in that: In step I, the concentration of the citric acid solution is 0.1~0.2 g / 100mL, the soaking time is 15~20 min, and the blanching time is 30~60 s; In step II, the low-temperature pre-freezing time is 11-12 h, the vacuum degree of vacuum freeze-drying is 10-30 Pa, and the vacuum freeze-drying time is 18-24 h. In step III, the sieve mesh size is 80-100 mesh.

7. The preparation method according to claim 4, characterized in that: In step (1), the preparation process of the fermented rice juice and rice wine lees is as follows: ① Inoculate glutinous rice with a compound microbial culture and carry out constant temperature fermentation. The compound microbial culture consists of Rhizopus and Saccharomyces cerevisiae. ②After fermentation, the fermented material is filtered through a plate and frame filter to obtain a clear liquid and a solid. The solid is rice wine lees, and the clear liquid is clarified to obtain rice wine juice.

8. The preparation method according to claim 7, characterized in that: In step ①, the Rhizopus content is 1×10⁻⁶. 8 ~1×10 9 CFU / g, Rhizopus inoculation amount in glutinous rice was 0.3~0.4% (w / w); Saccharomyces cerevisiae content was 1×10 8 ~1×10 9 The inoculation amount of brewing yeast in glutinous rice was 0.1~0.2% (w / w) CFU / g; the constant temperature fermentation temperature was 28~30℃, and the constant temperature fermentation time was 45~50 h; In step ②, the clarification treatment temperature is 4~6℃ and the clarification treatment time is 8~10 h.

9. The preparation method according to claim 4, characterized in that: In step (2), the ultrasonic treatment power is 200~300 W, the ultrasonic treatment temperature is 20~25℃, the ultrasonic treatment frequency is 20~25 kHz, the ultrasonic treatment time is 10~15 min, and the device is stirred once every 3~3.5 min during the ultrasonic treatment. In step (3), the temperature for static fermentation is 25~30℃, and the time for static fermentation is 20~30 min; In step (4), the mass of the small dough ball is 15~20 g, and the thickness of the round cake blank is 0.8~1.2 cm; In step (5), the frying pan is preheated to 160~180℃, and the frying time is 1.5~2.5 minutes for the upper and lower surfaces respectively.

10. The preparation method according to claim 9, characterized in that: In step (2), the ultrasonic power is 220 W, the ultrasonic temperature is 22℃, the ultrasonic frequency is 20 kHz, the ultrasonic time is 12 min, and the device is stirred once every 3 min during ultrasonic treatment. In step (3), the temperature for resting and proofing is 27°C and the time for resting and proofing is 25 min. In step (4), the mass of the small dough ball is 17 g, and the thickness of the round cake blank is 1 cm; In step (5), the frying pan is preheated to 170°C and the frying time is 2 minutes for each of the upper and lower surfaces.

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