A process for the cyclone separation of rice bran

Abstract

The present application relates to a kind of rice bran cyclone separation process.First, rice bran is crushed, is treated by ultrasonic wave, vacuum filtration, drying, and defatted rice bran is obtained;Defatted rice bran is placed in constant temperature and humidity box, its moisture content is adjusted, is separated by cyclone, and target product is obtained.The present application obtains the optimization condition of rice bran cyclone separation process through experiment: when flow rate is 9kg / h, fan frequency is 60Hz, and the moisture content of rice bran is 6.18%, the recovery rate of cyclone separator secondary port reaches 7.38%.The physical properties of different rice bran components obtained by cyclone separation are more uniform, and the difference of chemical components is more significant, which is beneficial to the grading processing and utilization of rice bran, and provides technical support for the industrial production of rice bran.

Description

Technical Field

[0001] This invention relates to a rice bran cyclone separation process, which belongs to the field of food processing. Background Technology

[0002] Rice bran contains various bioactive substances and nutrients, including vitamins, proteins, phenolic compounds, and trace minerals. For a long time, rice bran has often been used as animal feed or discarded directly, resulting in a high-value utilization rate of less than 20%. This not only causes a significant waste of rice bran resources but also limits the development of its potential value. Currently, domestic research mainly combines rice processing quality with the nutritional composition of rice bran, typically involving centralized recycling and mixed utilization. However, grading rice bran is key to improving its value for subsequent processing and utilization.

[0003] Air classification systems separate coarse and fine rice bran for separate utilization, improving utilization efficiency and product quality. Air classification can be used for grading wheat flour and separating protein-rich components from soybean flour. Cyclone separation, a type of air classification, uses the centrifugal force generated by a high-speed rotating airflow to separate materials from the airflow by particles of different sizes or densities with different settling velocities. Cyclone separation is widely used in the food and chemical industries, but research on cyclone separation of rice bran is extremely limited both domestically and internationally.

[0004] Therefore, it is necessary to further explore and study the separation of rice bran components using cyclone separation in order to promote practical applications. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the present invention provides a rice bran cyclone separation process.

[0006] The technical solution adopted in this invention is as follows:

[0007] A rice bran cyclone separation process includes the following steps:

[0008] (1) After the rice bran is crushed and sieved, the crushed rice bran is weighed and placed in a container. Anhydrous ethanol is added at a ratio of 1:10-15 g / mL. The mixture is then subjected to ultrasonic treatment, vacuum filtration, and drying to obtain defatted rice bran.

[0009] (2) Place defatted rice bran in a constant temperature and humidity chamber, adjust its moisture content, and then separate it by cyclone to obtain the target product.

[0010] The conditions for defatting rice bran in step (1) are as follows: material-to-liquid ratio 1:10-15 g / mL, ultrasonic treatment time 30-50 min, ultrasonic temperature 50-70℃, ultrasonic power 100-175 W, vacuum degree during vacuum filtration 0.08-0.12 MPa, and drying conditions at 100-105℃ for 10-20 min.

[0011] The optimal conditions for degreasing rice bran are: a material-to-liquid ratio of rice bran to anhydrous ethanol of 1:15 g / mL, ultrasonic treatment time of 40 min, treatment temperature of 70℃, ultrasonic power of 175 W, vacuum degree of 0.1 MPa, and drying conditions of 105℃ for 15 min.

[0012] The conditions for step (2) of defatted rice bran cyclone separation are: rice bran flow rate of 5.4-12.6 kg / h, fan frequency of 40-60 Hz, and rice bran moisture content of 3.11-9.05%.

[0013] The optimal conditions for defatted rice bran cyclone separation are: rice bran flow rate of 9 kg / h, blower frequency of 60 Hz, and moisture content of rice bran before processing of 6.18%.

[0014] Beneficial effects of the present invention

[0015] (1) This invention uses ultrasonic-anhydrous ethanol to degrease rice bran, and then separates the degreased rice bran into different components through cyclone separation, which is beneficial for the graded processing and utilization of rice bran. This cyclone separation process is simple to operate, convenient and fast, and has a certain reference value for the precise grading and research of rice bran. It will promote the structural adjustment and overall efficiency improvement of rice bran in the rice processing industry.

[0016] (2) Compared with raw rice bran, the rice bran obtained by cyclone separation in this invention has significantly higher protein and total dietary fiber content (46.02% and 34.26%, respectively). 50 The particle size decreased from 220.00 μm to 12.60 μm; the water solubility index and swelling power increased by 70.06% and 99.53%, respectively; the content of flavonoids and polyphenols with antioxidant properties also increased.

[0017] (3) This invention significantly improves the physical properties of rice bran and effectively enhances its nutritional value through cyclone separation. This not only benefits the subsequent processing and utilization of rice bran in the food industry, but also provides technical support for the industrial production of rice bran. Attached Figure Description

[0018] Figure 1 The effect of the material-to-liquid ratio on the degreasing rate of rice bran;

[0019] Figure 2 The effect of ultrasonic time on the degreasing rate of rice bran;

[0020] Figure 3 The effect of ultrasonic temperature on the degreasing rate of rice bran;

[0021] Figure 4 The effect of ultrasonic power on the degreasing rate of rice bran;

[0022] Figure 5The effect of rice bran flow rate on the recovery rate of the secondary inlet of a cyclone separator;

[0023] Figure 6 The effect of fan frequency on the recovery rate of the secondary inlet of a cyclone separator;

[0024] Figure 7 The effect of rice bran moisture content on the recovery rate of the secondary inlet of a cyclone separator;

[0025] Figure 8 Comparison of water-holding capacity, oil-holding capacity, water solubility index, and swelling power of graded rice bran samples. Detailed Implementation

[0026] The technical solution of the present invention will be further described in detail below with reference to specific embodiments.

[0027] Example 1: Optimization of Ultrasonic Degreasing Process for Rice Bran

[0028] 1.1 Single-factor experiment on ultrasonic degreasing of rice bran

[0029] Weigh the pulverized rice bran and add anhydrous ethanol to it in beakers according to different material-to-liquid ratios (1:5, 1:7.5, 1:10, 1:12.5, 1:15 g / mL). Perform ultrasonic degreasing of rice bran under the conditions of ultrasonic time (20, 30, 40, 50, 60 min), ultrasonic temperature (30, 40, 50, 60, 70℃), and ultrasonic power (100, 125, 175, 225, 250 W). Investigate the effects of these four factors on the degreasing effect of rice bran.

[0030] Rice bran was vacuum filtered and dried to obtain degreased rice bran. The vacuum degree of filtration was 0.1 MPa, and the drying was carried out at 105℃ for 15 minutes.

[0031] The results of the single-factor experiment are as follows Figures 1-4 As shown, within the material-to-liquid ratio range of 1:5-1:12.5 g / mL, the degreasing rate increased with the increase of anhydrous ethanol dosage. The maximum degreasing rate of 88.97% was achieved when the material-to-liquid ratio reached 1:12.5 g / mL. With the extension of ultrasonic time, the degreasing rate showed a trend of first increasing and then decreasing. The best degreasing rate was achieved when the ultrasonic time was 40 min, reaching 89.04%. The maximum degreasing rate of 86.26% was achieved when the ultrasonic temperature was 60℃. The best degreasing rate of 93.81% was achieved when the ultrasonic power was 125 W.

[0032] Therefore, the preliminary suitable conditions for ultrasonic treatment of rice bran are: material-to-liquid ratio of 1:10-15 g / mL, ultrasonic time of 30-50 min, ultrasonic temperature of 50-70℃, and ultrasonic power of 100-175 W.

[0033] 1.2 Orthogonal Optimization Experiment

[0034] Based on the single-factor experiment in 1.1, the material-liquid ratio (A), ultrasonic time (B), ultrasonic temperature (C) and ultrasonic power (D) were selected as factors, and the degreasing rate was used as the index to conduct an orthogonal optimization experiment. The results are shown in Table 1.

[0035] Table 1. Factors and levels in the orthogonal experimental design of ultrasonic degreasing of rice bran.

[0036]

[0037] Based on the single-factor experiment, L9(4) was selected. 3 The orthogonal experimental design table was used to optimize the ultrasonic degreasing process of rice bran. The experimental results are shown in Table 2.

[0038] Table 2. Results of the orthogonal experiment on ultrasonic degreasing of rice bran.

[0039]

[0040] Note: The K value represents the sum of the indicators at each level of each factor.

[0041] According to the range analysis of the orthogonal experiment, the order of importance of the influencing factors of ultrasonic degreasing is: material-liquid ratio (A) > ultrasonic temperature (C) > ultrasonic power (D) > ultrasonic time (B).

[0042] Table 2 shows that the optimal experimental combination for the degreasing process is A3B2C3D3, which means adding anhydrous ethanol at a material-to-liquid ratio of 1:15 g / mL, treating for 40 min under ultrasonic power of 175 W and ultrasonic temperature of 70 °C, and performing three parallel measurements. The resulting degreasing rate was 96.22%, which is higher than the degreasing rate of experiment No. 8.

[0043] Example 2: Optimization of the defatted rice bran cyclone separation process

[0044] 2.1 Defatted Rice Bran Cyclone Separation Process

[0045] The prepared defatted rice bran was placed in a constant temperature and humidity chamber (temperature 25℃, relative humidity 80%) to adjust the moisture content. Under the conditions of rice bran flow rate (1.8, 5.4, 9.0, 12.6 kg / h), fan frequency (30, 40, 50, 60 Hz), and rice bran moisture content (3.11, 6.18, 9.05, 12.10%), the defatted rice bran was subjected to cyclone separation for 2 minutes to investigate the effects of these three factors on the efficiency of defatted rice bran cyclone separation.

[0046] The results of the single-factor experiment are as follows Figures 5-7As shown, within the flow rate range of 1.8-12.6 kg / h, the recovery rate of the secondary inlet of the cyclone separator first increases and then decreases with increasing flow rate; when the flow rate reaches 9.0 kg / h, the recovery rate of the secondary inlet of the cyclone separator is the highest at 6.13%. With the continuous increase of the fan frequency, the recovery rate of the secondary inlet of the cyclone separator gradually increases, and when the fan frequency reaches 60 Hz, the recovery rate gradually stabilizes, at which point the recovery rate of the secondary inlet of the cyclone separator reaches 6.70%. When the moisture content increases, the recovery rate of the secondary inlet of the cyclone separator first increases and then decreases, with the optimal recovery rate of 6.88% at a moisture content of 6.18%.

[0047] Therefore, the suitable conditions for cyclone separation of defatted rice bran were initially obtained as follows: flow rate 5.4-12.6 kg / h, fan frequency 40-60 Hz, and rice bran moisture content 3.11-9.05%.

[0048] 2.2 Orthogonal Optimization Experiment

[0049] Based on the single-factor experiment in 2.1, flow rate (A), fan frequency (B) and moisture content (C) were selected as factors, and the recovery rate of the secondary inlet of the cyclone separator was used as the index to conduct an orthogonal optimization experiment. The results are shown in Table 3.

[0050] Table 3. Factors and levels in the orthogonal experimental design of defatted rice bran cyclone separation.

[0051]

[0052] Based on the single-factor experiment, L9(4) was selected. 3 The orthogonal experimental design table was used to optimize the process of defatted rice bran cyclone separation. The experimental results are shown in Table 4.

[0053] Table 4. Results of the orthogonal experiment for cyclone separation of defatted rice bran.

[0054]

[0055] Note: The K value represents the sum of the indicators at each level of each factor.

[0056] Range analysis of the orthogonal experiment shows that the order of importance of the influencing factors in defatted rice bran cyclone separation is: moisture content (C) > fan frequency (B) > flow rate (A) > blank (D). Blank (D) represents the comparison without any experimental factors in the orthogonal table.

[0057] Therefore, the optimal experimental theoretical combination for the defatted rice bran cyclone separation process is A2B3C2D3. Under the conditions of a flow rate of 9.0 kg / h, a moisture content of 6.18%, and a fan frequency of 60 Hz, the rice bran was graded using a cyclone separator. After three parallel measurements, the recovery rate of the secondary inlet of the cyclone separator was 7.38%, which is higher than the recovery rate of the secondary inlet of the cyclone separator in experiment No. 9.

[0058] Example 3: Performance of rice bran treated with ultrasonic degreasing and cyclone separation

[0059] 3.1 Basic Components of Rice Bran Graded Samples

[0060] The basic components of the graded rice bran were determined, and the results are shown in Table 5.

[0061] Table 5. Basic component content (%) of graded rice bran samples

[0062]

[0063] Note: 1. Different lowercase letters in the upper right corner of the same column indicate significant differences (P<0.05).

[0064] 2. All component contents in the table are on a dry basis.

[0065] In Table 5, rice bran treated differently is represented by codes. Z represents rice bran that passed through a 40-mesh standard sieve; X0 represents rice bran degreased by ultrasound and anhydrous ethanol; X1 represents rice bran collected at the first stage of a cyclone separator; and X2 represents rice bran collected at the second stage of a cyclone separator.

[0066] Table 5 shows that, compared with rice bran Z, the fat content of rice bran decreased from 14.37% to 1.19% after ultrasonic treatment, while the protein, ash, and total dietary fiber contents of rice bran all increased significantly. The protein, ash, and total dietary fiber contents of rice bran X2 collected in the secondary hopper increased by 46.02%, 202.08%, and 34.26%, respectively, compared with rice bran Z. Compared with Z, the starch content of both X0 and X1 increased significantly, with X1 having the highest starch content at 34.96%.

[0067] 3.2 Determination of the physical properties of rice bran

[0068] 3.2.1 Particle size determination

[0069] The particle size and distribution of the sample were measured using a laser particle size analyzer. The particle size distribution curve was used to obtain the D... 10 D 50 D 90 Particle size, which represents the particle size corresponding to the cumulative particle size distribution percentage of the sample reaching 10%, 50%, and 90%, respectively.

[0070] Formula for calculating the particle size span of rice bran grading samples: Particle size span = (D...) 90 -D 10 ) / D 50 The measurement results are shown in Table 6.

[0071] Table 6. Particle size of rice bran samples after grading

[0072]

[0073] Note: Different lowercase letters in the upper right corner of the same column indicate significant differences (P<0.05).

[0074] As shown in Table 6, the particle size of X2 is significantly smaller than that of other samples, D 90 Reaching 43.90μm, D 50 The particle size span reached 12.60 μm. The particle size span reflects the uniformity of the particle size distribution; the smaller the value, the more uniform the particle size distribution. X2's span is significantly larger than other samples, indicating a less uniform particle size distribution. However, X2's specific surface area is significantly increased, from 156.70 μm compared to Z. 2 / kg reached 650.30m 2 / kg indicates good particle dispersibility and more uniform mixing with other powders or additives.

[0075] 3.2.2 Measurement of hydration characteristics

[0076] (1) Water holding capacity / oil holding capacity measurement

[0077] The rice bran sample was dispersed in deionized water and corn oil at a ratio of 0.05:1 (w:v) and incubated in a water bath at 60℃ for 30 min. The samples were then centrifuged at 4000 rpm for 20 min, the supernatant was removed, and the mass of the centrifuge tube containing the precipitate was determined.

[0078] The formulas for calculating water-holding capacity and oil-holding capacity are as follows:

[0079] In the formula: m0 is the sample mass (g), m1 is the centrifuge tube mass (g), and m2 is the centrifuge tube mass containing precipitate (g).

[0080] (2) Determination of water solubility index

[0081] The water solubility index was determined according to AACC 44-15A. Rice bran samples and deionized water were dispersed in centrifuge tubes at a ratio of 1:50 (w:v), mixed thoroughly, and then placed in an 80℃ water bath for 30 min. The mixture was then centrifuged at 4000 rpm for 20 min, and the supernatant was poured into a pre-weighed evaporating dish and dried at 105℃ to constant weight.

[0082] Formula for calculating water solubility index:

[0083] In the formula: m0 is the sample mass (g), m1 is the evaporating dish mass (g), and m2 is the evaporating dish mass containing precipitate (g).

[0084] (3) Expansion force

[0085] Take 0.3g of rice bran sample and place it in a 10mL graduated test tube. Add 6mL of deionized water, mix thoroughly, and let stand at room temperature for 20 hours. Formula for calculating expansion force:

[0086] In the formula: m0 is the sample mass (g), V1 is the sample volume (mL), and V2 is the volume of the sample after absorbing water and swelling (mL).

[0087] The results of the hydration characteristics determination of rice bran graded samples are as follows: Figure 8 As shown.

[0088] Depend on Figure 8 It can be seen that the water-holding capacity of the four different rice bran samples differed significantly. Water-holding capacity reflects water retention ability; from Z to X2, the water-holding capacity increased from 3.06 g / g to 4.21 g / g. However, there was no significant difference in the oil-holding capacity of the four different rice bran samples. The water solubility index and swelling power of the rice bran samples separated by cyclone separation increased significantly. From Z to X2, the water solubility index increased from 20.91% to 35.56%, meaning that the water solubility index of X2 increased by 70.06%. Compared with Z, the swelling power of X2 increased by 99.53%. Different lowercase letters in the figure represent significant differences (P<0.05).

[0089] 3.3 Determination of mineral content in rice bran

[0090] (1) Heavy metal determination

[0091] Cadmium, chromium, and lead were determined according to GB5009.268-2016, and the results are shown in Table 7.

[0092] Table 7. Heavy metal content (mg / kg) in graded rice bran samples.

[0093]

[0094] Note: 1. Different lowercase letters in the upper right corner of the same column indicate significant differences (P<0.05).

[0095] 2. Standard GB 2762-2022 stipulates that the maximum residue limits for cadmium and chromium in milled grain products are 0.1 mg / kg and 1 mg / kg, respectively, and the maximum residue limit for lead in grains and their products is 0.2 mg / kg.

[0096] As shown in Table 7, according to the above standards, the cadmium content of the four different rice bran samples did not exceed the maximum residue limit. Compared with Z, the lead content of X0, X1, and X2 was significantly reduced, and the lead content of X2 was within the safe range.

[0097] (2) Determination of trace element and macro element content

[0098] According to GB5009.268-2016 standard, the elements selenium, zinc, copper, iron, calcium, magnesium and potassium in graded rice bran samples were determined, and the results are shown in Table 8.

[0099] Table 8. Trace and macro element contents (mg / kg) of graded rice bran samples.

[0100]

[0101] Note: Different lowercase letters in the upper right corner of the same column indicate significant differences (P<0.05).

[0102] Table 8 shows that the magnesium and potassium contents of the graded rice bran samples differed significantly. After cyclone separation, the contents of the six essential elements (zinc, copper, calcium, iron, magnesium, and potassium) in X0, X1, and X2 were significantly increased compared to Z, with X2 showing the highest content. The contents of zinc, copper, calcium, iron, magnesium, and potassium in X2 were 1.36, 1.54, 1.98, 2.35, 3.40, and 2.77 times those in Z, respectively.

[0103] (3) Determination of flavonoids and polyphenols

[0104] Weigh 0.1 g of sample into a 2 mL centrifuge tube, add 1 mL of methanol (analytical grade), and extract at 60 °C for 4 h. Take 0.5 mL of crude extract, add 4.5 mL of methanol; then add 0.3 mL of 5% NaNO2 solution, and let stand at room temperature for 5 min; then add 0.3 mL of 10% AlCl3 solution, and let stand for 6 min; finally add 4 mL of 1 mol / L NaOH, add water to make up to 10 mL, let stand for 15 min, and finally measure the absorbance at 510 nm.

[0105] Weigh 0.25 g of rice bran, add 0.5 mL of 80% methanol aqueous solution (containing 0.2% vitamin C), mix well, and extract by ultrasonication at room temperature for 30 min. Centrifuge at 12000 rpm for 10 min, collect the supernatant, and repeat the extraction twice. Combine the two supernatants and mix well. If necessary, dilute or concentrate, and collect the supernatant for analysis. Analyze the polyphenol content in the extract using ultra-high performance liquid chromatography (UPLC). The chromatographic column was a Waters HSS T3 (50 × 2.1 mm, 1.8 μm), the flow rate was 0.3 mL / min, the column temperature was 40 ℃, the injection volume was 2 μL, and the mobile phase was: phase A was ultrapure aqueous solution (containing 0.1% formic acid), and phase B was acetonitrile solution (containing 0.1% formic acid), with gradient elution.

[0106] The results of the determination of flavonoid and polyphenol content in graded rice bran samples are shown in Table 9.

[0107] Table 9 Flavonoid and Polyphenol Content in Graded Rice Bran Samples

[0108]

[0109] Note: Different lowercase letters in the upper right corner of the same line indicate significant differences (P<0.05).

[0110] As shown in Table 9, compared with Z, the total flavonoid and total polyphenol contents of X2 increased by 9.1% and 89.45%, respectively. After cyclone separation, the contents of protocatechuic acid, protocatechuic aldehyde, vanillin, syringaldehyde, rutin, and daidzein were all significantly increased. In particular, the contents of protocatechuic aldehyde and rutin in X2 were 3.00 and 2.59 times that of Z, respectively.

Claims

1. A rice bran cyclone separation process, characterized in that, Includes the following steps: (1) After the rice bran is crushed and sieved, the crushed rice bran is weighed and placed in a container. Anhydrous ethanol is added at a ratio of 1:10-15 g / mL. The mixture is then subjected to ultrasonic treatment, vacuum filtration, and drying to obtain defatted rice bran. The ultrasonic treatment time is 30-50 min, the ultrasonic temperature is 50-70 ℃, the ultrasonic power is 100-175 W, the vacuum degree during vacuum filtration is 0.08-0.12 MPa, and the drying conditions are drying at 100-105 ℃ for 10-20 min. (2) Place defatted rice bran in a constant temperature and humidity chamber, adjust its moisture content, and then separate it by cyclone to obtain the target product; The flow rate of rice bran during cyclone separation is 5.4-12.6 kg / h, the fan frequency is 40-60 Hz, and the moisture content of rice bran is 3.11-9.05%.

2. The process as described in claim 1, characterized in that, The conditions for defatting rice bran in step (1) are as follows: The ratio of rice bran to anhydrous ethanol was 1:15 g / mL. The ultrasonic treatment time was 40 min, the ultrasonic temperature was 70 ℃, the ultrasonic power was 175 W, the vacuum degree was 0.1 MPa, and the drying conditions were 105 ℃ for 15 min.

3. The process as described in claim 1, characterized in that, The conditions for step (2) of defatted rice bran cyclone separation are: rice bran flow rate of 9 kg / h, fan frequency of 60 Hz, and rice bran moisture content of 6.18%.

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