Preparation method and application of high-dispersity fried millet

Abstract

The invention belongs to the field of functional food processing, and particularly relates to a preparation method and application of high-dispersity fried millet. By treating millet, millet starch can be pre-gelatinized, and a porous structure is formed, so that on one hand, the bioavailability can be improved, and on the other hand, the loading of functional components can be increased, and the functional components are slowly released through the porous structure, so that the intestinal absorption efficiency is improved; maillard reaction products generated in the frying process can have a synergistic effect with components in the compound spleen-tonifying nutrient solution through segmented frying of the millet, so that the effects of tonifying the spleen and nourishing the stomach are improved, and the intestinal health is improved; and the treated millet can reduce particle aggregation, and can be dispersed more uniformly during subsequent application, so that the stability and the taste are improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of functional food processing, and particularly relates to a preparation method of high-dispersibility stir-fried foxtail millet and application thereof. BACKGROUND

[0002] In view of the problems in the prior art, the application provides a preparation method of high-dispersibility stir-fried foxtail millet.

[0003] Another purpose of the application is to provide application of the high-dispersibility stir-fried foxtail millet in a functional food for invigorating the spleen and nourishing the stomach.

[0004] The application adopts the technical scheme for realizing the above purpose: The application provides a preparation method of high-dispersibility stir-fried foxtail millet, comprising the following steps: (1) raw material pretreatment: the foxtail millet is soaked and then steamed, and then rapidly cooled to 0 DEG C and subjected to freezing treatment, and then dehydrated after being taken out; (2) enzyme treatment: the foxtail millet after dehydration is sprayed with a mixed enzyme solution, and then subjected to pulse treatment; (3) dynamic stir-frying: the foxtail millet after enzyme treatment is subjected to dynamic stir-frying; (4) structure puffing and pore forming: the foxtail millet after stir-frying is subjected to microwave treatment and steam treatment in sequence, and subjected to microwave-steam alternating cycle treatment to form foxtail millet with a hierarchical porous structure; (5) nutrition strengthening: a compound spleen-invigorating nutrient solution is coated on the surface of the foxtail millet with a hierarchical porous structure by using a fluidized bed bottom spraying technology, the air inlet temperature is 40 DEG C, and the atomization pressure is 0.8 MPa.

[0005] Preferably, in step (1), the soaking time is 4-5 h; the steaming is carried out at 80-85 DEG C for 15-18 min; the freezing treatment is carried out at a temperature of-5-0 DEG C for 1-2 h; and the dehydration is to a water content of 30%-35%.

[0006] Preferably, in step (2), the mixed enzyme solution contains 0.5% alpha-amylase, 0.3% beta-amylase and 0.5% pepsin, and the balance is water; the addition amount of the mixed enzyme solution accounts for 10-15% of the mass of the foxtail millet; and the pulse treatment is carried out at a pulse electric field with a strength of 20 kV / cm, a pulse width of 10 mu s and a frequency of 200 Hz at 40 DEG C for 1 h.

[0007] Preferably, in step (3), the specific process of the dynamic stir-frying is as follows: the first stage is 120 DEG C for 5 min, the second stage is 150 DEG C for 2 min, and the third stage is 180 DEG C for 3 min.

[0008] Preferably, in step (4), the microwave treatment is 1 minute at a power of 800 W; and the steam treatment is 30 seconds at a temperature of 100 DEG C; and the microwave-steam alternating cycle treatment is 3 times.

[0009] Preferably, in step (5), the preparation process of the compound spleen-nourishing nutrient solution is as follows: (a) dissolving of functional components: uniformly mix the yam polysaccharide solution, the triterpene of Poria cocos and the soybean phospholipid, and magnetically stir until transparent; (b) wall material compounding: homogenize the oat beta-glucan, chitosan and water in a 50 DEG C water bath to obtain a wall material solution; (c) mixing and emulsifying: mix the functional components and the wall material solution, and high-pressure homogenize to obtain an emulsion.

[0010] Preferably, the mass concentration of the yam polysaccharide solution is 1.5%; the mass ratio of the triterpene of Poria cocos and the soybean phospholipid is 1:3; the mass concentration of the yin chen peptide solution is 0.8%; the mass ratio of the yam polysaccharide, the triterpene of Poria cocos and the yin chen peptide is 1.5:0.5:0.8; in the wall material solution, the mass concentration of the oat beta-glucan is 3%, and the mass concentration of the chitosan is 1%; the mass ratio of the oat beta-glucan and the chitosan is 3-4:1; the mass ratio of the functional components and the wall material solution is 1:20-30; and the high-pressure homogenization is 40 MPa for 3 cycles.

[0011] Preferably, in step (5), the mass ratio of the compound spleen-nourishing nutrient solution and the millet with a hierarchical porous structure is 1:10-20.

[0012] The application further provides application of the high-dispersibility roasted millet prepared by the preparation method to a spleen-nourishing and stomach-nourishing functional food.

[0013] The millet used in the application is millet with high amylopectin content, low starch gelatinization temperature and delicate taste (for example, Shanxi millet).

[0014] The application has the following beneficial effects: (1) The application can pre-gelatinize millet starch and form a porous structure by treating the millet, which can improve bioavailability and increase the loading of functional components, and the functional components are slowly released through the porous structure, thereby increasing the intestinal absorption efficiency. (2) The Maillard reaction products generated during the roasting of the millet can synergistically act with the components in the compound spleen-nourishing nutrient solution, thereby improving the spleen-nourishing and stomach-nourishing effects and improving intestinal health; and the treated millet can reduce particle agglomeration, and can be more uniformly dispersed during subsequent application, thereby improving stability and taste. DETAILED DESCRIPTION

[0015] The technical solutions of the present application are further explained and described below through specific examples.

[0016] In some embodiments, the millet used by the present application is Shanxi millet, and the amylopectin content accounts for about 75-80% of the total starch content.

[0017] In the raw materials used by the present application: oat beta-glucan is purchased from Henan Pu Hui Biology; Pachyman triterpenoids are purchased from Boson Biological Technology; Coix seed peptide (Yi rice oligopeptide, 98%) is purchased from Shaanxi Yanhe Biology Technology Co., Ltd.; Dioscorea polysaccharide (effective polysaccharide content 30%) is purchased from Shanxi Ruisi Biology Technology Co., Ltd.; α-amylase (EnzymoPure™, 240 KNU-S / g), β-amylase (Type II-B, 20-80 units / mg protein (biuret)) and pepsin (EnzymoPure™, ≥15000 NF. units / mg) are purchased from Shanghai Aladdin Biochem Technology.

[0018] The preparation process of the compound spleen nourishing nutrient solution is as follows: (1) Dissolution of functional components: 1) Dioscorea polysaccharide (mass concentration 1.5%): dissolved in 60℃ deionized water, and magnetically stirred until transparent; 2) Pachyman triterpenoids (mass concentration 0.5%): pre-emulsified with soybean phospholipids (1:3), then add water, and ultrasonic treatment (200W, 10min); 3) Coix seed peptide (mass concentration 0.8%): dissolved in 60℃ deionized water, and magnetically stirred until transparent.

[0019] (2) Wall material compounding: mix oat beta-glucan and chitosan according to the mass ratio of 3:1, then add water to the mass concentration of oat beta-glucan is 3%, and the mixed solution is homogenized (10000 rpm, 5min) in 50℃ water bath.

[0020] (3) Mixing and emulsifying: mix the functional components (the mass ratio of Dioscorea polysaccharide, Pachyman triterpenoids and Coix seed peptide is 1.5:0.5:0.8) uniformly, then mix with the wall material solution (the volume ratio of functional component solution to wall material solution is 1:25), high-pressure homogenization (40MPa, 3 cycles), and get the emulsion.

[0021] Example 1 (1) Raw material pretreatment: after soaking the millet for 4 hours, steam at 80℃ for 15 minutes, then quickly cool to 0℃, and treat at-5℃ for 1h; dry and dehydrate by cold air to the water content of 35%; (2) Enzymatic treatment: the pretreated millet was sprayed with a mixed enzyme solution containing 0.5% a-amylase, 0.3% b-amylase and 0.5% pepsin (15% of the mass of the millet), and then treated for 1 hour at 40°C under the synergistic effect of a pulsed electric field (intensity 20 kV / cm, pulse width 10 μs, frequency 200 Hz); (4) Dynamic stir-frying: the millet after enzymatic treatment was placed in a frying pan, and the first stage was 5 minutes of stir-frying at 120°C, the second stage was 2 minutes of fragrance explosion at 150°C, and the third stage was 3 minutes of charring at 180°C, with the standard deviation of the surface temperature field of the materials in the pan controlled to be ≤1.8°C; (5) Structural puffing and pore forming: the millet after stir-frying was sequentially subjected to microwave treatment (power 800W, time 1 minute) and steam treatment (temperature 100°C, time 30 seconds), and the microwave-steam alternating cycle was repeated 3 times to form a hierarchical porous structure containing 10-50 μm large pores and 1-2 μm mesopores; (6) Nutrient fortification: a compound spleen-strengthening nutrient solution was prepared, and the compound spleen-strengthening nutrient solution was coated on the surface of the pretreated millet by using a fluidized bed bottom spraying technique, with the inlet air temperature being 40°C and the atomization pressure being 0.8 MPa.

[0022] Comparative Example 1 (1) Raw material pretreatment: the millet was soaked for 4 hours and then steamed at 80°C for 15 minutes; and then dehydrated by cold air blowing to a water content of 35%; The other steps were the same as in Example 1.

[0023] Comparative Example 2 (1) Raw material pretreatment: the millet was soaked for 4 hours and then steamed at 80°C for 15 minutes, and then quickly cooled to 0°C and treated at -5°C for 1 hour; and then dehydrated by cold air blowing to a water content of 35%; (2) Enzymatic treatment: the pretreated millet was sprayed with a mixed enzyme solution containing 0.5% a-amylase, 0.3% b-amylase and 0.5% pepsin, and then treated for 1 hour at 40°C under the synergistic effect of a pulsed electric field (intensity 20 kV / cm, pulse width 10 μs, frequency 200 Hz); (4) Dynamic stir-frying: the millet after enzymatic treatment was placed in a frying pan, and the first stage was 5 minutes of stir-frying at 120°C, the second stage was 2 minutes of fragrance explosion at 150°C, and the third stage was 3 minutes of charring at 180°C, with the standard deviation of the surface temperature field of the materials in the pan controlled to be ≤1.8°C; (5) Structural puffing: the millet after stir-frying was sequentially subjected to microwave treatment for 3 minutes to obtain puffed millet; (6) Nutrient fortification: a compound spleen-strengthening nutrient solution was prepared, and the compound spleen-strengthening nutrient solution was coated on the surface of the puffed millet by using a fluidized bed bottom spraying technique, with the inlet air temperature being 40°C and the atomization pressure being 0.8 MPa.

[0024] Example 1 In order to prove the superiority of the present application in solubility, functionality, nutrition, etc., the above properties of the present application are evaluated.

[0025] (I) Dispersing time and other indicators are evaluated by the following specific method: 1. Dispersing time: 1 g of sample is added to 100 mL of warm water (60°C), and the time (seconds) required for complete dispersion without clumping is recorded. 2. Specific surface area: a specific surface area analyzer is used for analysis, and nitrogen gas is used as the adsorption gas.

[0026] 3. Protein retention rate: the Kjeldahl method is used to analyze the protein content of the sample, and the untreated millet sample is used for comparison. (II) Animal experiments (1) Spleen index SPF level Kunming mice are selected, with half male and half female, weighing 18-22 g (6-8 weeks old), and adapted to the environment for 5 days (temperature 22±2°C, humidity 50%-60%, 12 h light-dark cycle, free feeding and drinking water). Sample size: 8 mice per group.

[0027] Grouping: control group (fed with untreated millet), Example 1 group, Comparative Example 1 and Comparative Example 2 groups (all according to 40% fried millet + basic feed); the daily food intake of mice is 3-5 g per mouse, and the nutritional composition of the basic feed in each group is consistent. Raising for 8 weeks.

[0028] Spleen index determination: 12 h before the end of the experiment, the mice were fasted but not watered, weighed (recorded the weight of the mice, unit: g). The mice were sacrificed by cervical dislocation, the abdominal cavity was opened aseptically, and the spleen was completely stripped (attention should be paid to avoid damaging the spleen tissue, and the surrounding fat and connective tissue were removed). The surface blood of the spleen was washed with physiological saline, and the water was absorbed with filter paper, and then immediately weighed (recorded the weight of the spleen, unit: mg) with an electronic balance (accuracy 0.1 mg).

[0029] The calculation formula is as follows: Spleen index = Spleen weight (mg) / Mouse weight (g) (2) Activated carbon propulsion rate determination (end of experiment operation, which can be performed synchronously with the spleen index) Activated carbon marker suspension: 5 g of activated carbon powder (particle size 200 mesh) is added to 100 mL of carboxymethylcellulose sodium (CMC-Na) solution (0.5% as a suspending agent), stirred uniformly, and degassed by ultrasonic to prepare a ready-to-use solution (freshly prepared).

[0030] 24 h before the end of the experiment, the mice in each group were fasted but not watered (to avoid interference of intestinal contents).

[0031] Active charcoal suspension was administered orally at 0.2 mL / 10 g body weight (using 1 mL gavage needle to gently operate, avoiding aspiration into the lung). 30 min after gavage, the mice were sacrificed by cervical dislocation, and the abdominal cavity was quickly opened, and the entire digestive tract (from the pylorus to the end of the rectum) was isolated. The small intestine (from the starting end of the duodenum to the ileocecal junction) was gently removed without pulling (to prevent the length of the intestinal tract from being stretched) and laid flat on filter paper.

[0032] The distance from the pylorus to the front end of the active charcoal in the small intestine was measured (unit: cm).

[0033] The total length of the small intestine was measured (unit: cm).

[0034] Active charcoal propulsion rate (%) = (active charcoal front propulsion distance ÷ small intestine total length) x 100% The present application significantly improves the dispersibility, functionality and nutrient retention of millet through the combined process of "multi-step enzymatic hydrolysis-dynamic roasting-microwave / steam alternation-functional nutrient liquid embedding". Compared with traditional roasted millet, the dispersing time of the product is shortened to 24 seconds, the specific surface area is increased by nearly 5 times, and better water reconstitution and instant properties are exhibited; at the same time, the protein retention rate is increased to 86.7%, which is significantly higher than that of the traditional process (65.5%); in the functional evaluation, the mouse spleen index and active charcoal propulsion rate are significantly improved, reaching 2.5 mg / g and 32.6% respectively, which reflects good spleen-strengthening and transportation-aiding effects. The product has the functions of quick infusion, nutrient retention and spleen-strengthening, and is suitable for the instant nutritional needs of the elderly, people with weak gastrointestinal function and people with fast-paced life.

Claims

1. A method for preparing highly dispersible fried millet, characterized in that: The following steps are involved: (1) Raw material pretreatment: millet is soaked and steamed, then quickly cooled to 0°C, frozen, and then dehydrated; (2) Enzymatic treatment: spraying the dehydrated millet with a mixed enzyme solution and then performing a pulse treatment; (3) Dynamic frying: Dynamic frying of the enzymatically hydrolyzed millet; (4) Structural expansion and pore formation: The millet after frying is subjected to microwave treatment and steam treatment in sequence, and the microwave-steam alternating cycle treatment is used to form millet with a hierarchical porous structure; (5) Nutritional enhancement: The fluidized bed bottom spraying technology was used to coat the spleen-strengthening compound nutrient solution on the surface of the millet with a graded porous structure. The inlet air temperature was 40°C and the atomization pressure was 0.8 MPa.

2. The preparation method according to claim 1, characterized in that In step (1), the soaking time is 4-5 hours; the steaming is performed at 80-85°C for 15-18 minutes; the freezing treatment is performed at -5-0°C for 1-2 hours; and the dehydration is performed to a water content of 30%-35%.

3. The preparation method according to claim 1 or 2, characterized in that In step (2), the mixed enzyme solution contains 0.5% α-amylase, 0.3% β-amylase and 0.5% pepsin, with the remainder being water; the amount of the mixed enzyme solution added is 10-15% of the mass of the millet; and the pulse treatment is carried out at 40°C for 1 hour under a pulsed electric field with an intensity of 20 kV / cm, a pulse width of 10 μs and a frequency of 200 Hz.

4. The preparation method according to claim 1, characterized in that In step (3), the specific process of dynamic frying is as follows: stir-frying at 120°C for 5 minutes in the first stage, sautéing at 150°C for 2 minutes in the second stage, and caramelizing at 180°C for 3 minutes in the third stage.

5. The preparation method according to claim 1, characterized in that In step (4), the microwave treatment is carried out at a power of 800 W for 1 minute; the steam treatment is carried out at a temperature of 100° C. for 30 seconds; and the microwave-steam alternating cycle treatment is repeated 3 times.

6. The preparation method according to claim 1, characterized in that In step (5), the preparation process of the composite spleen-strengthening nutrient solution is as follows: (a) Dissolution of functional components: Mix the yam polysaccharide solution, Poria triterpenoid-soybean lecithin solution, and coix seed peptide solution evenly and stir magnetically until transparent; (b) Wall material preparation: oat β-glucan, chitosan, and water were homogenized in a 50°C water bath to obtain a wall material solution; (c) Mixing and emulsification: The functional components are mixed with the wall material solution and homogenized under high pressure to obtain an emulsion.

7. The preparation method according to claim 6, characterized in that The mass concentration of the yam polysaccharide solution is 1.5%; the mass ratio of the Poria triterpenes and soybean lecithin is 1:3; the mass concentration of the coix seed peptide solution is 0.8%; the mass ratio of the yam polysaccharide: Poria triterpenes and coix seed peptide is: 1.5:0.5:0.8; in the wall material solution, the mass concentration of oat β-glucan is 3%, and the mass concentration of chitosan is 1%; the mass ratio of oat β-glucan and chitosan is 3-4:1; the mass ratio of the functional component and the wall material solution is 1:20-30; the high-pressure homogenization is at 40MPa and 3 cycles.

8. The preparation method according to claim 1, 6 or 7, characterized in that: In step (5), the mass ratio of the composite spleen-strengthening nutrient solution to the millet with a graded porous structure is 1:10-20.

9. Use of the highly dispersible fried millet prepared by the preparation method according to any one of claims 1 to 8 as a functional food for strengthening the spleen and stomach.

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