A kind of preparation method of spicy yellow fermented bean curd

Abstract

The invention relates to the technical field of food fermentation, and in particular to a method for preparing spicy yellow fermented bean curd. S1.1, weighing the following raw materials in parts by weight: 10-15 parts by weight of soybeans, 30-45 parts by weight of water, 0.1-0.3 parts by weight of gypsum powder, 0.5-0.8 parts by weight of mucor, 0.1-0.3 parts by weight of lactobacillus bulgaricus, 0.4-1.2 parts by weight of composite multifunctional particles, 1-10 parts by weight of salt water, 1-5 parts by weight of chili powder, 1-3 parts by weight of star anise, 0.4-0.6 parts by weight of cinnamon, and 0.5-0.7 parts by weight of pepper. parts by weight, 0.1-0.3 parts by weight of ginger, 0.8-1.2 parts by weight of salt, 1-2 parts by weight of rice wine and 0.6-0.8 parts by weight of vegetable oil; S1.2, pretreatment of raw materials and preparation of tofu blocks; S1.3, flavor fermentation to obtain spicy yellow fermented bean curd; the antioxidant effect and natural pigment effect of cryptoxanthin are used to give the product rich flavor quality, visual appeal and antioxidant effect, and acetylated distarch phosphate is used to improve the stability of cryptoxanthin and prolong the antioxidant effect of cryptoxanthin, so that it can stably exert its antioxidant effect during and after the fermentation process.

Description

Technical Field

[0001] The invention relates to the technical field of food fermentation, in particular to a method for preparing spicy yellow fermented bean curd. Background Art

[0002] Fermented bean curd, a traditional fermented food originating from ancient China, uses soybeans as its main raw material and is made through a series of tedious and delicate process including careful selection, cleaning, soaking, grinding, boiling, brine preparation, pressing, cutting, fermentation, etc. In the key link of fermentation, the fermented bean curd undergoes a transformation from bean fragrance to mellowness, from single to complex flavor. Through the action of specific microorganisms, the protein in tofu is broken down into a variety of amino acids and peptides, and the fat is partially hydrolyzed into glycerol and fatty acids. These changes give the fermented bean curd a delicious, delicate and smooth taste, as well as a unique aroma and color. It is an indispensable soul seasoning in many local specialty dishes.

[0003] However, during the fermentation process of fermented bean curd, since Mucor is an aerobic microorganism, oxidation will destroy the nutrients in the fermented bean curd, causing flavor changes and browning. In view of this, we propose a preparation method for spicy yellow fermented bean curd. Summary of the invention

[0004] The object of the present invention is to provide a method for preparing spicy yellow fermented bean curd to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides a method for preparing spicy yellow fermented bean curd, comprising the following steps: weighing the following raw materials in parts by weight: 10-15 parts by weight of soybeans, 30-45 parts by weight of water, 0.1-0.3 parts by weight of gypsum powder, 0.5-0.8 parts by weight of Mucor, 0.1-0.3 parts by weight of Lactobacillus bulgaricus, 0.4-1.2 parts by weight of composite multifunctional particles, 1-10 parts by weight of salt water, 1-5 parts by weight of chili powder, 1-3 parts by weight of star anise, 0.4-0.6 parts by weight of cinnamon bark, 0.5-0.7 parts by weight of pepper, 0.1-0.3 parts by weight of ginger, 0.8-1.2 parts by weight of salt, 1-2 parts by weight of rice wine and 0.6-0.8 parts by weight of vegetable oil; S1.2, soak soybeans in warm water at 30-40℃ for 8-12h, and use ultrasonic treatment for 5-10min every 2-3h to accelerate water penetration, grind the soaked soybeans into soy milk, filter to remove residue, boil the soy milk for sterilization, cool to 70-80℃, add gypsum powder, stir evenly and let stand for 15-20min, then pour into a mold covered with gauze, wrap the gauze tightly, place a heavy object to press into shape, and continue pressing for 30-50min to obtain tofu blocks; S1.3. Under sterile conditions, pre-culture and expand culture of Mucor and Lactobacillus bulgaricus to prepare Mucor liquid and Lactobacillus bulgaricus liquid, mix them in proportion to obtain a mixed liquid, spray the mixed liquid evenly on the surface of the cut tofu blocks, and sprinkle with composite multifunctional particles. The fermentation temperature is 25-27°C, the humidity is 87-90%, the pH value is 4.5-5.5, and the solid-state fermentation lasts for 5-6 days. Subsequently, spray saline with a mass fraction of 15-22% to convert it into partial liquid fermentation, and continue fermenting for 3-4 days. After the fermentation is completed, add chili powder, star anise, cinnamon, pepper, ginger, salt, rice wine and vegetable oil into the container, mix them thoroughly and evenly to obtain a mixed seasoning, then add the tofu blocks to the mixed seasoning, and turn them over so that the surface of the tofu blocks is evenly covered with the mixed seasoning. The pickling time is 12-24 hours. Finally, pasteurization is used to terminate the fermentation and fix the flavor to obtain a spicy yellow fermented bean curd.

[0006] Preferably, in S1.3, the concentration of the Mucor species in the Mucor liquid is 3 to 4.5×10 4 cfu / mL.

[0007] Preferably, in S1.3, the concentration of Lactobacillus bulgaricus is 0.5 to 1×10 4 cfu / mL.

[0008] Preferably, in S1.3, the Mucor bacterial solution and the Lactobacillus bulgaricus bacterial solution are mixed in a volume ratio of 5:2.5-3.

[0009] Preferably, in S1.3, the mass ratio of the mixed bacterial liquid to the tofu blocks is 1:8-13.

[0010] Preferably, the steps for preparing the composite multifunctional particles are as follows: The cryptoxanthin is dissolved in ethanol to form a core material solution, and then the acetylated distarch phosphate is dispersed in deionized water to form a wall material solution, and then a citric acid solution is added to adjust the pH of the wall material solution, Tween 20 is added to the wall material solution, and the mixture is stirred thoroughly until completely mixed, and the core material solution is added to the wall material solution containing Tween 20 at 5000-8000 rpm of a high-speed shear mixer, and stirring is continued for 10-15 minutes until a stable emulsion is formed, and the emulsion is poured into a shallow dish, and placed in a refrigerator precooled to minus 70-85°C, and the emulsion is quickly frozen for 20-30 minutes, and the frozen emulsion is transferred to a freeze dryer, and the freeze dryer parameters are set. After freeze drying, the powder is collected and placed in a dryer, and dried at room temperature for 4-6 hours to obtain composite multifunctional particles.

[0011] As an antioxidant, cryptoxanthin helps protect the raw materials from oxidative stress in the early stages of fermentation, especially when exposed to oxygen. This is because the unsaturated fatty acids in soybeans are easily oxidized, resulting in deterioration of flavor and odor. Secondly, after fermentation, cryptoxanthin can also serve as a natural pigment, giving the product a brighter yellow hue and enhancing the product's visual appeal. Finally, cryptoxanthin can be converted into vitamin A in the body, which can improve the nutritional value of yellow fermented bean curd. However, due to its instability during fermentation, cryptoxanthin is easily affected by environmental factors or partially degraded by microorganisms, resulting in weakened antioxidant and natural pigment effects of cryptoxanthin. Therefore, acetylated distarch phosphate is added for modification, and acetylated distarch phosphate is used for microencapsulation to improve the stability of cryptoxanthin, so that cryptoxanthin can tolerate fermentation conditions and remain stable, provide color to the product after fermentation, and continue to exert its antioxidant effect.

[0012] Acetylated distarch phosphate has good water retention. Since the fermentation of Mucor requires a higher humidity, the volatilization of water can be effectively controlled. In addition, Mucor can produce amylase, which can decompose acetylated distarch phosphate, providing more nutrients for the growth of Mucor. Therefore, in terms of the growth environment and nutrient supply, it provides Mucor with more suitable growth conditions, effectively promotes the growth of Mucor, and improves the fermentation effect and efficiency.

[0013] Preferably, the concentration of the citric acid solution is 0.1-1 M, and the pH of the wall material solution is 5-7.

[0014] Preferably, the added amount of Tween 20 is 0.1-5% of the mass of acetylated distarch phosphate.

[0015] Preferably, the parameters of the freeze dryer include a cold trap temperature of -45-55°C, a vacuum degree of 0.1-0.5 Pa, a primary drying time of 12-24 hours, and a secondary drying time of 6-12 hours.

[0016] Preferably, the composite multifunctional particles are prepared by mixing cryptoxanthin and acetylated distarch phosphate in a mass ratio of 1:4-6.

[0017] Compared with the prior art, the present invention has the following beneficial effects: In the preparation method of the spicy yellow fermented bean curd, cryptoxanthin is used as an antioxidant to ensure that the raw materials in the preparation process of the yellow fermented bean curd are protected from oxidative stress, and nutritional loss, flavor deterioration and browning are avoided. Acetylated distarch phosphate is used to improve the stability of cryptoxanthin, so that it can tolerate fermentation conditions and remain stable until the end of fermentation, providing natural pigments for the product, giving the product a brighter yellow hue, and enhancing the visual appeal of the product. At the same time, acetylated distarch phosphate has good water retention capacity, can provide a suitable growth environment for Mucor, and additionally provide more nutrients for the growth of Mucor, thereby effectively promoting the fermentation effect and efficiency. DETAILED DESCRIPTION

[0018] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0019] A method for preparing spicy yellow fermented bean curd of the present invention comprises the following steps: S1.1, weigh the following raw materials in parts by weight: 10-15 parts by weight of soybeans, 30-45 parts by weight of water, 0.1-0.3 parts by weight of gypsum powder, 0.5-0.8 parts by weight of Mucor, 0.1-0.3 parts by weight of Lactobacillus bulgaricus, 0.4-1.2 parts by weight of composite multifunctional particles, 1-10 parts by weight of salt water, 1-5 parts by weight of chili powder, 1-3 parts by weight of star anise, 0.4-0.6 parts by weight of cinnamon, 0.5-0.7 parts by weight of pepper, 0.1-0.3 parts by weight of ginger, 0.8-1.2 parts by weight of salt, 1-2 parts by weight of rice wine and 0.6-0.8 parts by weight of vegetable oil; S1.2, soak soybeans in warm water at 30-40℃ for 8-12h, and use ultrasonic treatment for 5-10min every 2-3h to accelerate water penetration, grind the soaked soybeans into soy milk, filter to remove residue, boil the soy milk for sterilization, cool to 70-80℃, add gypsum powder, stir evenly and let stand for 15-20min, then pour into a mold covered with gauze, wrap the gauze tightly, place a heavy object to press into shape, and continue pressing for 30-50min to obtain tofu blocks; S1.3. Under sterile conditions, pre-culture and expand culture of Mucor and Lactobacillus bulgaricus to prepare Mucor culture liquid and Lactobacillus bulgaricus culture liquid, mix them according to proportion to obtain a mixed culture liquid, spray the mixed culture liquid evenly on the surface of the cut tofu blocks, and sprinkle with composite multifunctional particles, the fermentation temperature is 25-27°C, the humidity is 87-90%, the pH value is 4.5-5.5, the solid-state fermentation lasts for 5-6 days, then spray saline with a mass fraction of 15-22% to convert to partial liquid fermentation, and continue fermentation for 3-4 days. After the fermentation is completed, add chili powder, star anise, cinnamon, pepper, ginger, salt, rice wine and vegetable oil into the container, mix them thoroughly and evenly to obtain a mixed seasoning, then add the tofu blocks into the mixed seasoning, and turn them over so that the surface of the tofu blocks is evenly covered with the mixed seasoning, the pickling time is 12-24 hours, and finally the fermentation is terminated by pasteurization and the flavor is fixed to obtain a spicy yellow fermented bean curd; Embodiment 1: A method for preparing spicy yellow fermented bean curd, comprising the following steps: S1.1, weigh the following raw materials in parts by weight: 15 parts by weight of soybean, 45 parts by weight of water, 0.3 parts by weight of gypsum powder, 0.8 parts by weight of Mucor, 0.3 parts by weight of Lactobacillus bulgaricus, 1.2 parts by weight of composite multifunctional microparticles, 10 parts by weight of salt water, 5 parts by weight of chili powder, 3 parts by weight of star anise, 0.6 parts by weight of cinnamon, 0.7 parts by weight of pepper, 0.3 parts by weight of ginger, 1.2 parts by weight of salt, 2 parts by weight of rice wine and 0.8 parts by weight of vegetable oil; the composite multifunctional microparticles are prepared by mixing cryptoxanthin and acetylated distarch phosphate in a mass ratio of 1:4; S1.2, soak soybeans in 40℃ warm water for 12h, and use ultrasonic treatment for 5min every 2h to accelerate water penetration, grind the soaked soybeans into soy milk, filter to remove residue, boil the soy milk for sterilization, cool to 80℃, add gypsum powder, stir evenly and let stand for 15min, then pour into a mold covered with gauze, wrap the gauze tightly, place a heavy object to press into shape, and continue pressing for 50min to obtain tofu blocks; The cryptoxanthin is dissolved in ethanol to form a core material solution, and then the acetylated distarch phosphate is dispersed in deionized water to form a wall material solution, and then a 0.5M citric acid solution is added to adjust the pH of the wall material solution to 6, and Tween 20 is added to the wall material solution, wherein the amount of Tween 20 added is 1% of the mass of the acetylated distarch phosphate, and the mixture is stirred thoroughly until completely mixed. At 8000rpm of a high-speed shear mixer, the core material solution is added to the wall material solution containing Tween 20, and stirring is continued for 15 minutes until a stable emulsion is formed, the emulsion is poured into a shallow dish, and placed in a refrigerator precooled to minus 80°C, and the emulsion is quickly frozen for 30 minutes, and the frozen emulsion is transferred to a freeze dryer, and the freeze dryer parameters are set, the cold trap temperature is minus 55°C, the vacuum degree is 0.3Pa, the primary drying time is 24 hours, and the secondary drying is 12 hours. After freeze drying, the powder is collected and placed in a dryer, and dried at room temperature for 4 hours to obtain composite multifunctional particles; S1.3. Under sterile conditions, pre-culture and expand the culture of Mucor and Lactobacillus bulgaricus to prepare Mucor culture liquid and Lactobacillus bulgaricus culture liquid, wherein the concentration of Mucor species in the Mucor culture liquid is 3.5×10 4 cfu / mL, and the strain concentration of Lactobacillus bulgaricus was 0.8×10 4 cfu / mL, Mucor culture liquid and Lactobacillus bulgaricus culture liquid were mixed in a volume ratio of 5:3 to obtain a mixed culture liquid, and the mixed culture liquid was evenly sprayed on the surface of the cut tofu blocks, wherein the mass ratio of the mixed culture liquid to the tofu blocks was 1:13, and the composite multifunctional particles were sprinkled, the fermentation temperature was 26°C, the humidity was 90%, the pH value was 5, the solid-state fermentation lasted for 5 days, and then 15% mass fraction of brine was sprayed to convert it into partial liquid fermentation, and the fermentation was continued for 3 days. After the fermentation was completed, chili powder, star anise, cinnamon, pepper, ginger, salt, rice wine and vegetable oil were added to the container, and after fully mixing, a mixed seasoning was obtained, and the tofu blocks were added to the mixed seasoning, and turned over so that the surface of the tofu blocks was evenly covered with the mixed seasoning. The pickling time was 24 hours, and finally the fermentation was terminated by pasteurization and the flavor was fixed to obtain a spicy yellow fermented bean curd.

[0020] Embodiment 2: A method for preparing spicy yellow fermented bean curd, comprising the following steps: S1.1, weigh the following raw materials in parts by weight: 15 parts by weight of soybean, 45 parts by weight of water, 0.3 parts by weight of gypsum powder, 0.8 parts by weight of Mucor, 0.3 parts by weight of Lactobacillus bulgaricus, 1.2 parts by weight of composite multifunctional microparticles, 10 parts by weight of salt water, 5 parts by weight of chili powder, 3 parts by weight of star anise, 0.6 parts by weight of cinnamon, 0.7 parts by weight of pepper, 0.3 parts by weight of ginger, 1.2 parts by weight of salt, 2 parts by weight of rice wine and 0.8 parts by weight of vegetable oil; the composite multifunctional microparticles are prepared by mixing cryptoxanthin and acetylated distarch phosphate in a mass ratio of 1:5; S1.2, soak soybeans in 40℃ warm water for 12h, and use ultrasonic treatment for 5min every 2h to accelerate water penetration, grind the soaked soybeans into soy milk, filter to remove residue, boil the soy milk for sterilization, cool to 80℃, add gypsum powder, stir evenly and let stand for 15min, then pour into a mold covered with gauze, wrap the gauze tightly, place a heavy object to press into shape, and continue pressing for 50min to obtain tofu blocks; The cryptoxanthin is dissolved in ethanol to form a core material solution, and then the acetylated distarch phosphate is dispersed in deionized water to form a wall material solution, and then a 0.5M citric acid solution is added to adjust the pH of the wall material solution to 6, and Tween 20 is added to the wall material solution, wherein the amount of Tween 20 added is 1% of the mass of the acetylated distarch phosphate, and the mixture is stirred thoroughly until completely mixed. At 8000rpm of a high-speed shear mixer, the core material solution is added to the wall material solution containing Tween 20, and stirring is continued for 15 minutes until a stable emulsion is formed, the emulsion is poured into a shallow dish, and placed in a refrigerator precooled to minus 80°C, and the emulsion is quickly frozen for 30 minutes, and the frozen emulsion is transferred to a freeze dryer, and the freeze dryer parameters are set, the cold trap temperature is minus 55°C, the vacuum degree is 0.3Pa, the primary drying time is 24 hours, and the secondary drying is 12 hours. After freeze drying, the powder is collected and placed in a dryer, and dried at room temperature for 4 hours to obtain composite multifunctional particles; S1.3. Under sterile conditions, pre-culture and expand the culture of Mucor and Lactobacillus bulgaricus to prepare Mucor culture liquid and Lactobacillus bulgaricus culture liquid, wherein the concentration of Mucor species in the Mucor culture liquid is 3.5×10 4 cfu / mL, and the strain concentration of Lactobacillus bulgaricus was 0.8×10 4 cfu / mL, Mucor culture liquid and Lactobacillus bulgaricus culture liquid were mixed in a volume ratio of 5:3 to obtain a mixed culture liquid, and the mixed culture liquid was evenly sprayed on the surface of the cut tofu blocks, wherein the mass ratio of the mixed culture liquid to the tofu blocks was 1:13, and the composite multifunctional particles were sprinkled, the fermentation temperature was 26°C, the humidity was 90%, the pH value was 5, the solid-state fermentation lasted for 5 days, and then 15% mass fraction of brine was sprayed to convert it into partial liquid fermentation, and the fermentation was continued for 3 days. After the fermentation was completed, chili powder, star anise, cinnamon, pepper, ginger, salt, rice wine and vegetable oil were added to the container, and after fully mixing, a mixed seasoning was obtained, and the tofu blocks were added to the mixed seasoning, and turned over so that the surface of the tofu blocks was evenly covered with the mixed seasoning. The pickling time was 24 hours, and finally the fermentation was terminated by pasteurization and the flavor was fixed to obtain a spicy yellow fermented bean curd.

[0021] Embodiment 3: A method for preparing spicy yellow fermented bean curd, comprising the following steps: S1.1, weigh the following raw materials in parts by weight: 15 parts by weight of soybean, 45 parts by weight of water, 0.3 parts by weight of gypsum powder, 0.8 parts by weight of Mucor, 0.3 parts by weight of Lactobacillus bulgaricus, 1.2 parts by weight of composite multifunctional microparticles, 10 parts by weight of salt water, 5 parts by weight of chili powder, 3 parts by weight of star anise, 0.6 parts by weight of cinnamon, 0.7 parts by weight of pepper, 0.3 parts by weight of ginger, 1.2 parts by weight of salt, 2 parts by weight of rice wine and 0.8 parts by weight of vegetable oil; the composite multifunctional microparticles are prepared by mixing cryptoxanthin and acetylated distarch phosphate in a mass ratio of 1:6; S1.2, soak soybeans in 40℃ warm water for 12h, and use ultrasonic treatment for 5min every 2h to accelerate water penetration, grind the soaked soybeans into soy milk, filter to remove residue, boil the soy milk for sterilization, cool to 80℃, add gypsum powder, stir evenly and let stand for 15min, then pour into a mold covered with gauze, wrap the gauze tightly, place a heavy object to press into shape, and continue pressing for 50min to obtain tofu blocks; The cryptoxanthin is dissolved in ethanol to form a core material solution, and then the acetylated distarch phosphate is dispersed in deionized water to form a wall material solution, and then a 0.5M citric acid solution is added to adjust the pH of the wall material solution to 6, and Tween 20 is added to the wall material solution, wherein the amount of Tween 20 added is 1% of the mass of the acetylated distarch phosphate, and the mixture is stirred thoroughly until completely mixed. At 8000rpm of a high-speed shear mixer, the core material solution is added to the wall material solution containing Tween 20, and stirring is continued for 15 minutes until a stable emulsion is formed, the emulsion is poured into a shallow dish, and placed in a refrigerator precooled to minus 80°C, and the emulsion is quickly frozen for 30 minutes, and the frozen emulsion is transferred to a freeze dryer, and the freeze dryer parameters are set, the cold trap temperature is minus 55°C, the vacuum degree is 0.3Pa, the primary drying time is 24 hours, and the secondary drying is 12 hours. After freeze drying, the powder is collected and placed in a dryer, and dried at room temperature for 4 hours to obtain composite multifunctional particles; S1.3. Under sterile conditions, pre-culture and expand the culture of Mucor and Lactobacillus bulgaricus to prepare Mucor culture liquid and Lactobacillus bulgaricus culture liquid, wherein the concentration of Mucor species in the Mucor culture liquid is 3.5×10 4 cfu / mL, and the strain concentration of Lactobacillus bulgaricus was 0.8×10 4cfu / mL, Mucor culture liquid and Lactobacillus bulgaricus culture liquid were mixed in a volume ratio of 5:3 to obtain a mixed culture liquid, and the mixed culture liquid was evenly sprayed on the surface of the cut tofu blocks, wherein the mass ratio of the mixed culture liquid to the tofu blocks was 1:13, and the composite multifunctional particles were sprinkled, the fermentation temperature was 26°C, the humidity was 90%, the pH value was 5, the solid-state fermentation lasted for 5 days, and then 15% mass fraction of brine was sprayed to convert it into partial liquid fermentation, and the fermentation was continued for 3 days. After the fermentation was completed, chili powder, star anise, cinnamon, pepper, ginger, salt, rice wine and vegetable oil were added to the container, and after fully mixing, a mixed seasoning was obtained, and the tofu blocks were added to the mixed seasoning, and turned over so that the surface of the tofu blocks was evenly covered with the mixed seasoning. The pickling time was 24 hours, and finally the fermentation was terminated by pasteurization and the flavor was fixed to obtain a spicy yellow fermented bean curd.

[0022] Embodiment 4: A method for preparing spicy yellow fermented bean curd, comprising the following steps: S1.1, weigh the following raw materials in parts by weight: 10 parts by weight of soybean, 30 parts by weight of water, 0.1 parts by weight of gypsum powder, 0.5 parts by weight of Mucor, 0.1 parts by weight of Lactobacillus bulgaricus, 1.2 parts by weight of composite multifunctional microparticles, 1 part by weight of salt water, 1 part by weight of chili powder, 1 part by weight of star anise, 0.4 parts by weight of cinnamon, 0.5 parts by weight of pepper, 0.1 parts by weight of ginger, 0.8 parts by weight of salt, 1 part by weight of rice wine and 0.6 parts by weight of vegetable oil; the composite multifunctional microparticles are prepared by mixing cryptoxanthin and acetylated distarch phosphate in a mass ratio of 1:6; S1.2, soak soybeans in 40℃ warm water for 12h, and use ultrasonic treatment for 5min every 2h to accelerate water penetration, grind the soaked soybeans into soy milk, filter to remove residue, boil the soy milk for sterilization, cool to 80℃, add gypsum powder, stir evenly and let stand for 15min, then pour into a mold covered with gauze, wrap the gauze tightly, place a heavy object to press into shape, and continue pressing for 50min to obtain tofu blocks; The cryptoxanthin is dissolved in ethanol to form a core material solution, and then the acetylated distarch phosphate is dispersed in deionized water to form a wall material solution, and then a 0.5M citric acid solution is added to adjust the pH of the wall material solution to 6, and Tween 20 is added to the wall material solution, wherein the amount of Tween 20 added is 1% of the mass of the acetylated distarch phosphate, and the mixture is stirred thoroughly until completely mixed. At 8000rpm of a high-speed shear mixer, the core material solution is added to the wall material solution containing Tween 20, and stirring is continued for 15 minutes until a stable emulsion is formed, the emulsion is poured into a shallow dish, and placed in a refrigerator precooled to minus 80°C, and the emulsion is quickly frozen for 30 minutes, and the frozen emulsion is transferred to a freeze dryer, and the freeze dryer parameters are set, the cold trap temperature is minus 55°C, the vacuum degree is 0.3Pa, the primary drying time is 24 hours, and the secondary drying is 12 hours. After freeze drying, the powder is collected and placed in a dryer, and dried at room temperature for 4 hours to obtain composite multifunctional particles; S1.3. Under sterile conditions, pre-culture and expand the culture of Mucor and Lactobacillus bulgaricus to prepare Mucor culture liquid and Lactobacillus bulgaricus culture liquid, wherein the concentration of Mucor species in the Mucor culture liquid is 3.5×10 4 cfu / mL, and the strain concentration of Lactobacillus bulgaricus was 0.8×10 4 cfu / mL, Mucor culture liquid and Lactobacillus bulgaricus culture liquid were mixed in a volume ratio of 5:3 to obtain a mixed culture liquid, and the mixed culture liquid was evenly sprayed on the surface of the cut tofu blocks, wherein the mass ratio of the mixed culture liquid to the tofu blocks was 1:13, and the composite multifunctional particles were sprinkled, the fermentation temperature was 26°C, the humidity was 90%, the pH value was 5, the solid-state fermentation lasted for 5 days, and then 15% mass fraction of brine was sprayed to convert it into partial liquid fermentation, and the fermentation was continued for 3 days. After the fermentation was completed, chili powder, star anise, cinnamon, pepper, ginger, salt, rice wine and vegetable oil were added to the container, and after fully mixing, a mixed seasoning was obtained, and the tofu blocks were added to the mixed seasoning, and turned over so that the surface of the tofu blocks was evenly covered with the mixed seasoning. The pickling time was 24 hours, and finally the fermentation was terminated by pasteurization and the flavor was fixed to obtain a spicy yellow fermented bean curd.

[0023] Embodiment 5: A method for preparing spicy yellow fermented bean curd, comprising the following steps: S1.1, weigh the following raw materials in parts by weight: 15 parts by weight of soybean, 45 parts by weight of water, 0.3 parts by weight of gypsum powder, 0.8 parts by weight of Mucor, 0.3 parts by weight of Lactobacillus bulgaricus, 0.4 parts by weight of composite multifunctional microparticles, 10 parts by weight of salt water, 5 parts by weight of chili powder, 3 parts by weight of star anise, 0.6 parts by weight of cinnamon, 0.7 parts by weight of pepper, 0.3 parts by weight of ginger, 1.2 parts by weight of salt, 2 parts by weight of rice wine and 0.8 parts by weight of vegetable oil; the composite multifunctional microparticles are prepared by mixing cryptoxanthin and acetylated distarch phosphate in a mass ratio of 1:6; S1.2, soak soybeans in 40℃ warm water for 12h, and use ultrasonic treatment for 5min every 2h to accelerate water penetration, grind the soaked soybeans into soy milk, filter to remove residue, boil the soy milk for sterilization, cool to 80℃, add gypsum powder, stir evenly and let stand for 15min, then pour into a mold covered with gauze, wrap the gauze tightly, place a heavy object to press into shape, and continue pressing for 50min to obtain tofu blocks; The cryptoxanthin is dissolved in ethanol to form a core material solution, and then the acetylated distarch phosphate is dispersed in deionized water to form a wall material solution, and then a 0.5M citric acid solution is added to adjust the pH of the wall material solution to 6, and Tween 20 is added to the wall material solution, wherein the amount of Tween 20 added is 1% of the mass of the acetylated distarch phosphate, and the mixture is stirred thoroughly until completely mixed. At 8000rpm of a high-speed shear mixer, the core material solution is added to the wall material solution containing Tween 20, and stirring is continued for 15 minutes until a stable emulsion is formed, the emulsion is poured into a shallow dish, and placed in a refrigerator precooled to minus 80°C, and the emulsion is quickly frozen for 30 minutes, and the frozen emulsion is transferred to a freeze dryer, and the freeze dryer parameters are set, the cold trap temperature is minus 55°C, the vacuum degree is 0.3Pa, the primary drying time is 24 hours, and the secondary drying is 12 hours. After freeze drying, the powder is collected and placed in a dryer, and dried at room temperature for 4 hours to obtain composite multifunctional particles; S1.3. Under sterile conditions, pre-culture and expand the culture of Mucor and Lactobacillus bulgaricus to prepare Mucor culture liquid and Lactobacillus bulgaricus culture liquid, wherein the concentration of Mucor species in the Mucor culture liquid is 3.5×10 4 cfu / mL, and the strain concentration of Lactobacillus bulgaricus was 0.8×10 4 cfu / mL, Mucor culture liquid and Lactobacillus bulgaricus culture liquid were mixed in a volume ratio of 5:3 to obtain a mixed culture liquid, and the mixed culture liquid was evenly sprayed on the surface of the cut tofu blocks, wherein the mass ratio of the mixed culture liquid to the tofu blocks was 1:13, and the composite multifunctional particles were sprinkled, the fermentation temperature was 26°C, the humidity was 90%, the pH value was 5, the solid-state fermentation lasted for 5 days, and then 15% mass fraction of brine was sprayed to convert it into partial liquid fermentation, and the fermentation was continued for 3 days. After the fermentation was completed, chili powder, star anise, cinnamon, pepper, ginger, salt, rice wine and vegetable oil were added to the container, and after fully mixing, a mixed seasoning was obtained, and the tofu blocks were added to the mixed seasoning, and turned over so that the surface of the tofu blocks was evenly covered with the mixed seasoning. The pickling time was 24 hours, and finally the fermentation was terminated by pasteurization and the flavor was fixed to obtain a spicy yellow fermented bean curd.

[0024] Embodiment 6: A method for preparing spicy yellow fermented bean curd, comprising the following steps: S1.1, weigh the following raw materials in parts by weight: 15 parts by weight of soybean, 45 parts by weight of water, 0.3 parts by weight of gypsum powder, 0.8 parts by weight of Mucor, 0.3 parts by weight of Lactobacillus bulgaricus, 0.8 parts by weight of composite multifunctional microparticles, 10 parts by weight of salt water, 5 parts by weight of chili powder, 3 parts by weight of star anise, 0.6 parts by weight of cinnamon, 0.7 parts by weight of pepper, 0.3 parts by weight of ginger, 1.2 parts by weight of salt, 2 parts by weight of rice wine and 0.8 parts by weight of vegetable oil; the composite multifunctional microparticles are prepared by mixing cryptoxanthin and acetylated distarch phosphate in a mass ratio of 1:6; S1.2, soak soybeans in 40℃ warm water for 12h, and use ultrasonic treatment for 5min every 2h to accelerate water penetration, grind the soaked soybeans into soy milk, filter to remove residue, boil the soy milk for sterilization, cool to 80℃, add gypsum powder, stir evenly and let stand for 15min, then pour into a mold covered with gauze, wrap the gauze tightly, place a heavy object to press into shape, and continue pressing for 50min to obtain tofu blocks; The cryptoxanthin is dissolved in ethanol to form a core material solution, and then the acetylated distarch phosphate is dispersed in deionized water to form a wall material solution, and then a 0.5M citric acid solution is added to adjust the pH of the wall material solution to 6, and Tween 20 is added to the wall material solution, wherein the amount of Tween 20 added is 1% of the mass of the acetylated distarch phosphate, and the mixture is stirred thoroughly until completely mixed. At 8000rpm of a high-speed shear mixer, the core material solution is added to the wall material solution containing Tween 20, and stirring is continued for 15 minutes until a stable emulsion is formed, the emulsion is poured into a shallow dish, and placed in a refrigerator precooled to minus 80°C, and the emulsion is quickly frozen for 30 minutes, and the frozen emulsion is transferred to a freeze dryer, and the freeze dryer parameters are set, the cold trap temperature is minus 55°C, the vacuum degree is 0.3Pa, the primary drying time is 24 hours, and the secondary drying is 12 hours. After freeze drying, the powder is collected and placed in a dryer, and dried at room temperature for 4 hours to obtain composite multifunctional particles; S1.3. Under sterile conditions, pre-culture and expand the culture of Mucor and Lactobacillus bulgaricus to prepare Mucor culture liquid and Lactobacillus bulgaricus culture liquid, wherein the concentration of Mucor species in the Mucor culture liquid is 3.5×10 4 cfu / mL, and the strain concentration of Lactobacillus bulgaricus was 0.8×10 4cfu / mL, Mucor culture liquid and Lactobacillus bulgaricus culture liquid were mixed in a volume ratio of 5:3 to obtain a mixed culture liquid, and the mixed culture liquid was evenly sprayed on the surface of the cut tofu blocks, wherein the mass ratio of the mixed culture liquid to the tofu blocks was 1:13, and the composite multifunctional particles were sprinkled, the fermentation temperature was 26°C, the humidity was 90%, the pH value was 5, the solid-state fermentation lasted for 5 days, and then 15% mass fraction of brine was sprayed to convert it into partial liquid fermentation, and the fermentation was continued for 3 days. After the fermentation was completed, chili powder, star anise, cinnamon, pepper, ginger, salt, rice wine and vegetable oil were added to the container, and after fully mixing, a mixed seasoning was obtained, and the tofu blocks were added to the mixed seasoning, and turned over so that the surface of the tofu blocks was evenly covered with the mixed seasoning. The pickling time was 24 hours, and finally the fermentation was terminated by pasteurization and the flavor was fixed to obtain a spicy yellow fermented bean curd.

[0025] Comparative Example 1: The method of Example 3 was adopted without adding composite multifunctional particles.

[0026] Comparative Example 2: The method of Example 3 was adopted, and cryptoxanthin was directly used without modifying cryptoxanthin through acetylation of distarch phosphate.

[0027] Comparative Example 3: The method of Example 3 was adopted, and acetylated distarch phosphate was directly used without modifying the acetylated distarch phosphate by cryptoxanthin.

[0028] The present invention adopts composite multifunctional particles to prepare spicy yellow fermented bean curd, wherein the performance index inspection items and inspection standards of the spicy yellow fermented bean curd are as follows: 20 sensory assessors were selected to evaluate and score the spicy yellow fermented bean curd prepared in Examples 1-6 and Comparative Examples 1-3, and the color, flavor and taste of the spicy yellow fermented bean curd were evaluated respectively. The lowest score for each item was 0 and the highest score was 10. The highest and lowest scores for each item were removed, and the average score was calculated. The samples were then placed in a constant temperature box at 40°C to observe the time when black spots or green spots appeared, so as to characterize the antioxidant effect of cryptoxanthin in the spicy yellow fermented bean curd.

[0029] According to the above standards, the preparation method of a spicy yellow fermented bean curd prepared in the above Examples 1-6 and Comparative Examples 1-3 was tested, and the obtained data are shown in Table 1: Table 1 Performance data of Examples 1-6 and Comparative Examples 1-3 The above data fully demonstrate that compared with Comparative Examples 1-3, Examples 1-6 can fully demonstrate the effect of the composite multifunctional particles on the flavor quality and antioxidant properties of spicy yellow fermented bean curd.

[0030] Since the present invention uses composite multifunctional particles to prepare spicy yellow fermented bean curd, the composite multifunctional particles effectively improve the flavor quality and antioxidant effect of the spicy yellow fermented bean curd, as follows: It can be seen from Examples 1-3 that as the proportion of components in the composite multifunctional particles continues to increase, the flavor quality and antioxidant effect of the spicy yellow fermented bean curd gradually improve. Acetylated distarch phosphate can improve the stability of the active ingredient of cryptoxanthin by forming a protective film, thereby preventing cryptoxanthin from being destroyed or inactivated during the fermentation process. In addition, the microcapsules prepared from acetylated distarch phosphate have a sustained-release property, which enables cryptoxanthin to be slowly released during storage, thereby continuously improving the flavor and providing an antioxidant effect, and increasing the oxidation time, thereby protecting the nutritional components from oxidation and avoiding flavor changes or browning of the yellow fermented bean curd.

[0031] It can be seen from Examples 3 and 4 that with the continuous change of the content of other components, the flavor quality and antioxidant effect of the spicy yellow fermented bean curd do not change significantly, indicating that small changes in other components within a certain range are not enough to significantly affect the flavor quality and antioxidant effect of the yellow fermented bean curd. It also shows that the key factor that determines the flavor quality and antioxidant effect of the yellow fermented bean curd is the composite multifunctional particles.

[0032] It can be seen from Examples 3, 5 and 6 that as the content of the composite multifunctional particles continues to change, the flavor quality and antioxidant effect of the spicy yellow fermented bean curd continue to change. Since the content of the composite multifunctional particles increases, the more cryptoxanthin is present, the better its antioxidant effect is, thereby better ensuring that the raw materials in the preparation process of the yellow fermented bean curd are protected from oxidative stress. At the same time, cryptoxanthin can also provide natural pigments, giving the product a brighter color, so the flavor quality and antioxidant effect of the spicy yellow fermented bean curd are better.

[0033] According to the above test experiments, the spicy yellow fermented bean curd prepared according to Example 3 has the best performance, so Example 3 is taken as the best example; By comparing Example 3 with Comparative Examples 1-3, it can be seen that: In Comparative Example 1, no composite multifunctional particles were added, and the flavor quality and antioxidant effect of the spicy yellow fermented bean curd were poor. Although soybeans contain antioxidant components, a large amount of antioxidant components were lost due to high-temperature cooking. Therefore, no additional composite multifunctional particles were added, and the adverse reactions caused by lipids and other easily oxidized components exposed to the air further damaged the quality of the fermented bean curd, resulting in the weakening of the flavor quality and antioxidant effect of the spicy yellow fermented bean curd.

[0034] In Comparative Example 2, cryptoxanthin was directly used without modifying it through acetylated distarch phosphate. The flavor quality and antioxidant effect of the spicy yellow fermented bean curd were poor. Cryptoxanthin is extremely sensitive to external conditions such as light, oxygen and pH value, especially without additional protection. These factors will accelerate its decomposition and reduce its stability and functional performance. This also illustrates the necessity of acetylated distarch phosphate to protect cryptoxanthin. Therefore, the flavor quality and antioxidant effect of the spicy yellow fermented bean curd are poor.

[0035] Comparative Example 3 directly uses acetylated distarch phosphate without modifying the acetylated distarch phosphate with cryptoxanthin. The flavor quality and antioxidant effect of the spicy yellow fermented bean curd are poor. Although acetylated distarch phosphate can prevent water loss and provide additional nutritional components for Mucor, it itself does not have obvious flavor quality contribution or antioxidant capacity. Therefore, it lacks the functional active component of cryptoxanthin and is difficult to achieve ideal flavor quality and antioxidant effect.

[0036] In summary, through the synergistic effect of cryptoxanthin and acetylated distarch phosphate, the antioxidant effect and natural pigment effect of cryptoxanthin are utilized to give the product rich flavor quality, visual appeal and antioxidant effect. Acetylated distarch phosphate is used to improve the stability of cryptoxanthin and prolong the antioxidant effect of cryptoxanthin, so that it can stably exert its antioxidant effect during and after fermentation. At the same time, acetylated distarch phosphate can be decomposed by amylase secreted by Mucor, which provides additional nutrients, thereby effectively promoting the fermentation effect and efficiency.

[0037] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and the above embodiments and descriptions are only preferred examples of the present invention, and are not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A method for preparing spicy yellow fermented bean curd, characterized in that: The following steps are involved: S1.1, weigh the following raw materials in parts by weight: 10-15 parts by weight of soybeans, 30-45 parts by weight of water, 0.1-0.3 parts by weight of gypsum powder, 0.5-0.8 parts by weight of Mucor, 0.1-0.3 parts by weight of Lactobacillus bulgaricus, 0.4-1.2 parts by weight of composite multifunctional particles, 1-10 parts by weight of salt water, 1-5 parts by weight of chili powder, 1-3 parts by weight of star anise, 0.4-0.6 parts by weight of cinnamon, 0.5-0.7 parts by weight of pepper, 0.1-0.3 parts by weight of ginger, 0.8-1.2 parts by weight of salt, 1-2 parts by weight of rice wine and 0.6-0.8 parts by weight of vegetable oil; S1.2, soak soybeans in warm water at 30-40℃ for 8-12h, and use ultrasonic treatment for 5-10min every 2-3h to accelerate water penetration, grind the soaked soybeans into soy milk, filter to remove residue, boil the soy milk for sterilization, cool to 70-80℃, add gypsum powder, stir evenly and let stand for 15-20min, then pour into a mold covered with gauze, wrap the gauze tightly, place a heavy object to press into shape, and continue pressing for 30-50min to obtain tofu blocks; S1.

3. Under sterile conditions, pre-culture and expand culture of Mucor and Lactobacillus bulgaricus to prepare Mucor liquid and Lactobacillus bulgaricus liquid, mix them in proportion to obtain a mixed liquid, spray the mixed liquid evenly on the surface of the cut tofu blocks, and sprinkle with composite multifunctional particles. The fermentation temperature is 25-27°C, the humidity is 87-90%, the pH value is 4.5-5.5, and the solid-state fermentation lasts for 5-6 days. Subsequently, spray saline with a mass fraction of 15-22% to convert it into partial liquid fermentation, and continue fermenting for 3-4 days. After the fermentation is completed, add chili powder, star anise, cinnamon, pepper, ginger, salt, rice wine and vegetable oil into the container, mix them thoroughly and evenly to obtain a mixed seasoning, then add the tofu blocks to the mixed seasoning, and turn them over so that the surface of the tofu blocks is evenly covered with the mixed seasoning. The pickling time is 12-24 hours. Finally, pasteurization is used to terminate the fermentation and fix the flavor to obtain a spicy yellow fermented bean curd.

2. The method for preparing spicy yellow fermented bean curd according to claim 1, characterized in that: In S1.3, the concentration of the Mucor species in the Mucor liquid is 3 to 4.5×10 4 cfu / mL.

3. The method for preparing spicy yellow fermented bean curd according to claim 1, characterized in that: In S1.3, the concentration of Lactobacillus bulgaricus is 0.5 to 1×10 4 cfu / mL.

4. The method for preparing spicy yellow fermented bean curd according to claim 1, characterized in that: In the S1.3, the Mucor bacterial solution and the Lactobacillus bulgaricus bacterial solution are mixed in a volume ratio of 5:2.5-3.

5. The method for preparing spicy yellow fermented bean curd according to claim 1, characterized in that: In S1.3, the mass ratio of the mixed bacterial liquid to the tofu blocks is 1:8-13.

6. The method for preparing spicy yellow fermented bean curd according to claim 1, characterized in that: The steps of preparing the composite multifunctional particles are specifically as follows: The cryptoxanthin is dissolved in ethanol to form a core material solution, and then the acetylated distarch phosphate is dispersed in deionized water to form a wall material solution, and then a citric acid solution is added to adjust the pH of the wall material solution, Tween 20 is added to the wall material solution, and the mixture is stirred thoroughly until completely mixed, and the core material solution is added to the wall material solution containing Tween 20 at 5000-8000 rpm of a high-speed shear mixer, and stirring is continued for 10-15 minutes until a stable emulsion is formed, and the emulsion is poured into a shallow dish, and placed in a refrigerator precooled to minus 70-85°C, and the emulsion is quickly frozen for 20-30 minutes, and the frozen emulsion is transferred to a freeze dryer, and the freeze dryer parameters are set. After freeze drying, the powder is collected and placed in a dryer, and dried at room temperature for 4-6 hours to obtain composite multifunctional particles.

7. The method for preparing spicy yellow fermented bean curd according to claim 6, characterized in that: The concentration of the citric acid solution is 0.1-1M, and the pH of the wall material solution is 5-7.

8. The method for preparing spicy yellow fermented bean curd according to claim 6, characterized in that: The added amount of Tween 20 is 0.1-5% of the mass of acetylated distarch phosphate.

9. The method for preparing spicy yellow fermented bean curd according to claim 6, characterized in that: The parameters of the freeze dryer are as follows: the cold trap temperature is minus 45-55°C, the vacuum degree is 0.1-0.5Pa, the primary drying time is 12-24h, and the secondary drying time is 6-12h.

10. The method for preparing spicy yellow fermented bean curd according to claim 6, characterized in that: The composite multifunctional particles are prepared by mixing cryptoxanthin and acetylated distarch phosphate in a mass ratio of 1:4-6.

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