Extraction method of symplocos paniculata kernel oil

Abstract

The invention discloses an extraction method of symplocos paniculata kernel oil, which comprises the following steps: putting symplocos paniculata kernel powder into a conical flask, adding an ethanol aqueous solution according to a material-liquid ratio of 1: (3-10), sealing the conical flask with a sealing film, and putting into a microwave oven with set time, power and temperature; and after microwave treatment, adjusting the pH value of the solution in the whole conical flask to 8-10 by using a sodium hydroxide solution, then adding a certain amount of sodium chloride, when the water bath kettle reaches a set temperature, putting the solution into the water bath kettle, carrying out an extraction reaction for a certain period of time, carrying out centrifugal separation, collecting supernatant oil, centrifuging the remaining water phase and slag phase again, and merging the supernatant oil obtained in the two times. According to the method for extracting the symplocos paniculata kernel oil by adopting the ethanol water extraction method, the process is relatively simple, green and environment-friendly, the quality of the extracted oil is better, and a theoretical basis and basic data can be provided for subsequent extraction of the symplocos paniculata kernel oil.

Description

Technical Field

[0001] The invention relates to separation, in particular to a method for extracting sandalwood kernel oil from sandalwood kernels. Background Art

[0002] White sandalwood is a tree species that can be used as a raw material for biodiesel and vegetable edible oil. It has a high fruit yield every year. The maximum fruit yield of a white sandalwood tree can reach 20kg, and the oil content of white sandalwood fruit can reach more than 36%. The fatty acid components of white sandalwood oil are mainly palmitic acid, stearic acid, oleic acid, linoleic acid and linolenic acid. The content of unsaturated fatty acids is more than 76.74%, and the physical and chemical properties are excellent. The three major industrial oil plant retrieval systems already have relevant data on white sandalwood. [4] It can be seen that sandalwood oil has great development prospects in food and industry.

[0003] So far, most of the reports on sandalwood research are about the biological characteristics of sandalwood, seedling technology, oil fatty acid composition and amino acids, physical and chemical properties of oils and fats, and the preparation of biodiesel from sandalwood raw material oil, but lack research on the extraction process of sandalwood oil. Ethanol water extraction is a green and environmentally friendly extraction technology compared to traditional extraction methods, and the extraction process is simple, safe, and the extracted oil has good quality. At the same time, studies have reported that microwave-assisted treatment has the effect of breaking cells and improving the extraction rate. Therefore, the inventors used single factor experiments, orthogonal experimental methods and response surface optimization methods to explore the effects of ethanol concentration and microwave pretreatment on the extraction of sandalwood kernel oil, and determined the optimal extraction process conditions for extracting sandalwood kernel oil by ethanol water extraction, providing technical references for the subsequent mass production of sandalwood kernel oil in the oil production industry. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method for extracting sandalwood kernel oil from sandalwood kernels in view of the deficiencies in the prior art, so as to achieve the purpose of improving the oil extraction rate.

[0005] The technical solution of the present invention is a method for extracting sandalwood kernel oil, characterized in that the extraction steps are as follows: (1) Shell the sandalwood seeds, dry and crush them, seal them and place them in a cool place for later use; (2) Put the sandalwood kernel powder in a conical flask and add ethanol water solution in a ratio of 1:3-10, seal the conical flask with a sealing film, and then put it in a microwave oven with set time, power and temperature for microwave treatment; (3) Use sodium hydroxide solution to adjust the pH value of the solution in the entire conical flask to 8-10, then add a certain amount of sodium chloride and place it in a water bath for extraction; (4) The extract is centrifuged to collect the clear oil on the upper layer, and the remaining water phase and residue phase are centrifuged again, and the two clear oils are combined to obtain the final product.

[0006] In step (2) of the above method, the ethanol volume fraction of the ethanol aqueous solution is 5-40%. Preferably, the ethanol volume fraction of the ethanol aqueous solution is 10%.

[0007] In step (2) of the above method, the microwave temperature is 55°C, the microwave power is 400-850W, and the microwave treatment time is 30-90min. More preferably, the microwave power is 700W, and the microwave treatment time is 75min.

[0008] In step (3) of the above method, the concentration of the sodium hydroxide solution is 0.1-0.5 mol / L. Preferably, the concentration of the sodium hydroxide solution is 0.3 mol / L.

[0009] In step (3) of the above method, the water bath temperature is 40-60°C, and the water bath extraction time is 1-4 h. Preferably, the water bath temperature is 60°C, and the water bath extraction time is 1 h.

[0010] In step (4) of the above method, the centrifugal speed is 6000-12000 r·min -1 , the centrifugation time was 15 min.

[0011] In step (1) of the above method, the solid-liquid ratio of the sandalwood kernel powder to the ethanol aqueous solution is 1:5.

[0012] The principle of the present invention is to summarize the optimal conditions for extracting sandalwood kernel oil by ethanol water extraction through single factor and orthogonal optimization of ethanol water bath extraction conditions and response surface optimization of microwave pretreatment conditions. The experimental results show that the optimal combination conditions for extracting sandalwood kernel oil by ethanol water extraction are: adding 10% ethanol at a solid-liquid ratio of 1 to 5, treating at a microwave temperature of 55°C and a microwave power of 700W for 75 minutes, adding 0.3 mol / L sodium chloride, and extracting in a water bath at 60°C for 1 hour. Under this condition, the oil extraction rate of sandalwood kernel oil is 29.78%.

[0013] The beneficial effects of the present invention are as follows: compared with traditional methods for extracting edible oil such as pressing and pre-pressing leaching, the extraction process of the ethanol-water extraction method is relatively simple, green and environmentally friendly, and the quality of the extracted oil is also better. Under the process conditions of the present invention, the oil extraction rate of the sandalwood kernel oil is high, and the method is suitable for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is the effect of ethanol volume fraction on the extraction rate of sandalwood kernel oil; Figure 2 This is the effect of microwave temperature on the oil extraction rate of sandalwood kernel oil; Figure 3 This is the effect of microwave time on the oil extraction rate of sandalwood kernel oil; Figure 4 This is the effect of microwave power on the oil extraction rate of sandalwood kernel oil; Figure 5 This is the effect of sodium chloride concentration on oil extraction rate; Figure 6 The contour map and response surface of the interaction between microwave temperature and time on oil extraction rate; Figure 7 The contour map and response surface of the interaction between microwave power and time on oil extraction rate; Figure 8 Contour map and response surface of the interaction between microwave power and temperature on oil extraction rate. DETAILED DESCRIPTION

[0015] 1. Experimental Methods 1. Pretreatment of sandalwood seeds Shell the sandalwood seeds, dry and crush them, seal them and place them in a cool place for later use.

[0016] 2. Process flow of extracting sandalwood kernel oil by ethanol-water extraction Sandalwood kernel → crush → ethanol aqueous solution → microwave treatment → add sodium chloride → heat extraction → centrifugal separation → collect the upper clear oil → centrifugal separation again → collect the upper clear oil → combine the two clear oils to obtain sandalwood kernel oil.

[0017] 3. Single factor test on the extraction of sandalwood kernel oil The solid-liquid ratio was set at 1:5 and the system pH was set at 9.

[0018] a. When the amount of sodium chloride added was 0.3 mol / L, the microwave treatment conditions were 500 W, 50 °C, 75 min, the water bath extraction temperature was 60 °C, and the water bath extraction time was 1 h, the effect of different ethanol volume fractions on the oil extraction rate of white sandalwood kernels was investigated; b. In the conditions of 10% ethanol, microwave treatment power of 500W, microwave treatment temperature of 50℃, sodium chloride addition of 0.3mol / L, water bath extraction temperature of 60℃, and water bath extraction time of 1h, the effect of different microwave treatment times on the oil extraction rate of white sandalwood kernels was investigated; c. The effect of different microwave treatment powers on the oil extraction rate of white sandalwood kernels was investigated under the conditions of 10% ethanol, microwave treatment time of 75 min, microwave treatment temperature of 50 °C, sodium chloride addition of 0.3 mol / L, water bath extraction temperature of 60 °C, and water bath extraction time of 1 h. d. Under the conditions of 10% ethanol, microwave treatment time of 75 min, microwave treatment power of 500 W, sodium chloride addition of 0.3 mol / L, water bath extraction temperature of 60 ° C, and water bath extraction time of 1 h, the effect of different microwave treatment temperatures on the oil extraction rate of sandalwood kernels was investigated.

[0019] e. Under the conditions of 10% ethanol, microwave treatment time of 75 min, microwave treatment temperature of 50°C, microwave treatment power of 800 W, water bath extraction temperature of 60°C, and water bath extraction time of 1 h, the effect of different amounts of sodium chloride addition on the oil extraction rate of sandalwood kernels was investigated.

[0020] 4. Orthogonal test method to optimize water bath extraction conditions According to the analysis of the test results, water bath extraction time (X1) and water bath extraction temperature (X2) were used as test factors, and the oil extraction rate of sandalwood was used as an indicator. Three groups of orthogonal experiments were carried out respectively. The design scheme of the orthogonal experiment method is shown in Table 1.

[0021]

[0022] (5) Optimization of microwave-assisted processing conditions using response surface methodology On the basis of the single factor experiment, a three-factor and three-level response surface experimental design was carried out with the sandalwood kernel oil extraction rate (Y) as the indicator and microwave treatment time (A), microwave treatment temperature (B) and microwave treatment power (C) as factors. The design scheme is shown in Table 2.

[0023]

[0024] (6) Data processing Design Expert 8.0.6 software was used for statistical analysis. P The difference was significant when the value was less than 0.05, and the graph was drawn using Excel software. The experimental data were obtained through 3 parallel experiments, and the results were expressed as mean value or ± standard deviation.

[0025] 2. Results and Analysis

[0026] like Figure 1 As shown in the figure, with the increase of ethanol concentration, the extraction rate of sandalwood kernel oil first increased to a maximum value and then decreased gradually. When the volume fraction of ethanol reached 10%, the extraction rate of sandalwood kernel oil reached a maximum of 26%. This is because the addition of ethanol can reduce the oil content in the emulsion and residue phase, which can have a good demulsification effect, thereby improving the extraction rate of sandalwood kernel oil.

[0027] (1) Effect of microwave treatment temperature on the oil extraction rate of sandalwood kernel oil The sandalwood kernel oil extraction experiment was carried out under the conditions of microwave time 75min, microwave power 500w and different microwave temperatures. The results are as follows Figure 2 shown.

[0028] See Figure 2It can be seen that with the increase of microwave temperature, when it reaches 50℃, the oil extraction rate of sandalwood kernel oil is the highest, reaching 27.30%. Thereafter, with the increase of microwave treatment temperature, the oil extraction rate decreases.

[0029] (2) Effect of microwave time on the oil extraction rate of sandalwood kernel oil Under the conditions of microwave temperature of 50℃ and power of 500W, the oil extraction experiment was carried out with different microwave treatment times. Figure 3 shown.

[0030] Depend on Figure 3 It can be seen that with the increase of microwave treatment time, the oil extraction rate of sandalwood kernel oil gradually increased. When the treatment time was 75 minutes, the oil extraction rate reached the highest value of 27.30%. However, as the microwave treatment time was increased thereafter, the oil extraction rate did not increase but decreased.

[0031] (3) Effect of microwave power on the oil extraction rate of sandalwood kernel oil Under the conditions of microwave treatment temperature of 50℃ and microwave treatment time of 75min, the oil extraction experiment of sandalwood kernel was carried out with different microwave powers. The results are as follows: Figure 4 shown.

[0032] according to Figure 4 It can be seen that the oil extraction rate in the test increases with the increase of microwave power, reaching the maximum value when the power is 800W. When the power is further increased, the oil extraction rate decreases instead.

[0033] The results of the microwave treatment of sandalwood kernel oil with different sodium chloride additions were as follows: 10% ethanol, microwave treatment time of 75 min, temperature of 50 °C, power of 800 W, water bath temperature of 60 °C, water bath extraction time of 1 h, and extraction of sandalwood kernel oil with different sodium chloride additions were as follows: Figure 5 shown.

[0034] Depend on Figure 5 It can be seen that with the increase of sodium chloride content, the growth trend of the oil extraction rate shows a trend of first rising and then falling. When the concentration of sodium chloride reaches 0.3 mol / L, the extraction rate of sandalwood kernel oil reaches the maximum value of 31.55%.

[0035] From the orthogonal test results in Table 3, it can be seen that the main and secondary factors affecting the oil extraction rate are X1>X2, and the best water bath conditions are a water bath temperature of 60°C, a water bath time of 1h, and an oil extraction rate of 31.55%. The oil extraction rate of sandalwood kernels was 30.07% after three repeated tests under the best water bath conditions, which is slightly lower than the oil extraction rate under the best conditions of the orthogonal test, proving that the best water bath conditions are available.

[0036]

[0037] 5. Optimization of Microwave Treatment Conditions by Response Surface Method According to the above single factor test results, the response surface test design was used to carry out the following response surface test with the extraction rate of sandalwood kernel oil (Y) as the index and microwave time (A), microwave temperature (B) and microwave power (C) as the factors. The experimental results are shown in Tables 4 and 5.

[0038]

[0039] The experimental results in Table 4 were analyzed using Design Expert 8.0.6 software, and multiple regression fitting was performed on the three factors of microwave time (A), microwave temperature (B) and microwave power (C), and the quadratic polynomial regression equation was obtained: Y=-609.745+3.48A+8.04B+0.798C-0.0063AB-0.000047AC-0.0059BC-0.020A 2 -0.028B 2 -0.00032C 2

[0040] Note: “*” indicates significant difference (0.01< P <0.05); “**” indicates extremely significant difference ( P <0.01).

[0041] According to the F value in Table 5, the factors affecting the extraction rate of sandalwood kernel oil are as follows: A microwave time > B microwave temperature > C microwave power. P The value is 0.0017, the lack of fit term is 0.0709, which is greater than 0.05, and the coefficient of determination of the model (R 2 ) was 0.9396, and the adjusted coefficient of determination (R Adj 2 ) is 0.8620, indicating that the model is extremely significant, the degree of fitting is relatively good, the regression effect of the equation is good, the model is credible, and its error is small. It can better predict the oil extraction rate of sandalwood kernel powder in the change of various microwave factors.

[0042] According to the response surface and contour shape, we can share the effects of microwave time, temperature and power on the oil extraction rate of sandalwood kernels. When the contour map is elliptical, it means that the interaction between the two factors is strong, and when it is circular, the interaction is weak. Figure 6 , 7 The contour plots in 8 show that the interactions between microwave temperature and microwave time, microwave power and microwave time are strong, while the interactions between microwave power and microwave time are weak. Figure 6The response surface in Figure 2 shows that when the microwave power is 800W, as the microwave time and temperature increase, the oil extraction rate of sandalwood kernel oil increases first and then decreases. In the range of microwave time of 69-79min and microwave temperature of 47-53℃, sandalwood kernel oil has a higher oil extraction rate. Figure 7 From the response surface, we can see that when the microwave temperature is 50℃, as the microwave time and power increase, the oil extraction rate in the response surface reaches a maximum value, and the sandalwood kernel has a higher oil extraction rate in the range of microwave time 70~81min and microwave power 710~805W. Figure 8 It can be seen that when the microwave time is 60 minutes, when the microwave power and temperature increase, the oil extraction rate of sandalwood kernels tends to first increase and then decrease. In the range of microwave power 700~800W and microwave temperature 47~55℃, sandalwood kernels have a higher oil extraction rate.

[0043] Through the analysis of Design Expert 8.0.6 software, it can be obtained that the optimal microwave conditions for microwave-assisted extraction of sandalwood kernel oil are: microwave treatment time of 74.21min, temperature of 55℃, and power of 711.48W. At this time, the extraction rate of sandalwood kernel oil is 30.382%. Considering the operability of the actual experiment, the optimal microwave treatment conditions are adjusted to: microwave time of 75min, microwave temperature of 55℃, and microwave power of 700W. After three repeated experiments under the adjusted conditions, the average oil extraction rate is 29.78%, which is close to the predicted oil extraction rate before adjustment. Therefore, it can be proved that the condition parameters for microwave treatment of sandalwood kernel oil after optimization by the above regression model are available.

[0044] Previous studies have shown that ethanol has a good demulsification effect. In this experiment, as the volume fraction of ethanol increases, the oil extraction rate tends to increase, reaching a maximum at 10%, and then decreasing. When the volume fraction of ethanol is 40%, the oil extraction rate increases. Considering the cost saving and avoiding reagent waste, this study selected the ethanol volume fraction of 10%.

[0045] In the single-factor experiment of microwave pretreatment, too high microwave temperature, too long microwave time, and too large microwave power will lead to the loss of ethanol solvent and reduce the oil extraction rate; the microwave treatment conditions are: treatment time 75min, microwave temperature 55℃, and microwave power 700W.

[0046] In the subsequent water bath experiment, in order to accelerate the salting out of the protein and increase the oil yield, sodium chloride was added. As the concentration of sodium chloride increased, the oil yield first increased and then decreased. When the concentration of sodium chloride exceeded 0.3 mol / L, the protein precipitated and was not easy to precipitate, which also reduced the oil extraction rate. Therefore, the concentration of sodium chloride was finally determined to be 0.3 mol / L.

[0047] Summarizing the experimental process and analyzing the results, it was found that the oil extraction rate of sandalwood kernel oil was significantly improved after adding microwave-assisted treatment and sodium chloride treatment, indicating that microwave treatment and sodium chloride salting-out do have the effect of improving the extraction rate of sandalwood kernel oil.

[0048] In this experiment, the optimal conditions for extracting sandalwood kernel oil by ethanol-water extraction were explored by single factor and orthogonal optimization of ethanol-water extraction conditions and response surface optimization of microwave pretreatment conditions. The results showed that the optimal combination of conditions for extracting sandalwood kernel oil by ethanol-water extraction was: adding 10% ethanol at a solid-liquid ratio of 1 to 5, treating at a microwave temperature of 55°C and a microwave power of 700W for 75 minutes, adding 0.3 mol / L sodium chloride, and extracting in a water bath at 60°C for 1 hour. Under these conditions, the oil extraction rate of sandalwood kernel oil was 29.78%.

Claims

1. A method for extracting sandalwood kernel oil, characterized in that: The extraction steps are as follows: Shell the white sandalwood seeds, dry and crush them, seal them and store them in a cool place for later use; Put the sandalwood kernel powder in a conical bottle and add ethanol water solution in a ratio of 1:3-10, seal the conical bottle mouth with a sealing film, and then put it in a microwave oven with set time, power and temperature for microwave treatment; Use sodium hydroxide solution to adjust the pH value of the solution in the entire conical flask to 8-10, then add a certain amount of sodium chloride and put it in a water bath for leaching; The extract is centrifuged to collect the clear oil on the upper layer, the remaining water phase and residue phase are centrifuged again, and the two clear oils are combined to obtain the final product.

2. The method for extracting sandalwood kernel oil according to claim 1, wherein: The ethanol volume fraction of the ethanol aqueous solution is 5-40%.

3. The method for extracting sandalwood kernel oil according to claim 1, wherein: The microwave temperature is 55°C, the microwave power is 400-850W, and the microwave treatment time is 30-90min.

4. The method for extracting sandalwood kernel oil according to claim 1, wherein: The concentration of the sodium hydroxide solution is 0.1-0.5 mol / L.

5. The method for extracting sandalwood kernel oil according to claim 1, characterized in that: The water bath temperature is 40-60°C, and the water bath extraction time is 1-4 h.

6. The method for extracting sandalwood kernel oil according to claim 1, characterized in that: Centrifugal speed is 6000-12000r·min -1 , the centrifugation time was 15 min.

7. The method for extracting sandalwood kernel oil according to claim 1, characterized in that: The solid-liquid ratio of the step (1) white sandalwood kernel powder to the ethanol aqueous solution is 1:5.

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