Enzymatic processing technology of camellia oleosa seed oil

Abstract

The invention relates to the technical field of camellia oleosa seed oil processing, in particular to an enzymatic processing technology of camellia oleosa seed oil. The invention provides a low-consumption and high-efficiency camellia oleosa seed oil enzymic method processing technology, by screening a domestic enzyme preparation, adding an oil extraction auxiliary agent before grinding and performing microwave pretreatment, the dosage of water and enzyme is remarkably reduced, the production cost is reduced, the generation of emulsion is inhibited from the source, the de-emulsification process is simplified, and the quality of camellia oleosa seed oil is improved. The method greatly improves the quality and yield of grease and by-products, realizes efficient enzymatic oil extraction of camellia oleifera seeds and high-valued utilization of by-products through pilot-scale test of 40-80 kg / batch of products, improves the overall economic benefit and environmental sustainability of camellia oleifera seed oil processing, and has wide application prospects. The invention provides a solid technical foundation for industrial production and comprehensive utilization of byproducts under green processing of the camellia oleosa seed oil enzyme method.

Description

Technical Field

[0001] The invention relates to the technical field of camellia oil processing, in particular to an enzymatic processing technology of camellia oil. Background Art

[0002] The nutritional value of camellia oil depends largely on its extraction and processing technology. The conventional processing methods currently suitable for industrialization are still pressing, solvent extraction and pre-pressing extraction. However, the pressing method has a low oil extraction rate, a high risk of toxin pollution, and severe protein denaturation; the extraction method has a high solvent residue and over-refining of the five de-refining steps, which leads to the production of trans fatty acids and polycyclic aromatic hydrocarbons, which is not conducive to the subsequent comprehensive utilization of by-products. As a new green technology, the aqueous enzyme method uses the activity of enzymes to catalyze substrate reactions to separate oils. Its production process is gentle, efficient, and environmentally friendly, with no toxin residues. By-products can be extracted at the same time, which is conducive to the value-added utilization of resources.

[0003] CN115232669A mentions a method for preparing tea oil containing squalene, by using 0.5% to 5% of one or more of protease, amylase, pectinase or cellulase, and performing two enzymatic hydrolysis for 4 to 12 hours to obtain an extraction rate of 36.8% to 70.3%. CN113667532A mentions a method for preparing tea oil containing squalene, by adding 0.5% to 2% NaHCO 3 CN102550659A mentions a method for extracting edible oil by microwave pretreatment water, wherein 0-90% ethanol, 0-10% NaHCO 3 In the presence of a leavening agent, microwave pretreatment of oil plants such as camellia seeds at 300-60000 W for 1-15 min can fully destroy the cell structure of oil plants, but the oil extraction rate is not mentioned. Our CN101906350A mentions a method for extracting oil from camellia seeds and recovering saponins and carbohydrate active substances, using a solid-liquid ratio of 1:3-6 g / mL, and the imported Novozymes pectinase is expensive.

[0004] In general, the existing camellia oil water enzymatic extraction process has problems such as high energy consumption, serious nutrient loss, low extraction rate and comprehensive utilization of by-products, and there are still many technical difficulties in industrial application, including: efficient crushing pretreatment technology based on the subcellular level of oil, large-scale oil separation equipment and multi-phase continuous separation technology, development of special enzyme preparations and process improvement technology to reduce enzyme costs, and green simultaneous extraction and value-added utilization technology of by-products and functional factors. These problems restrict the healthy development of the camellia oil industry. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides an enzymatic processing technology for camellia oil, comprising: mixing crushed camellia kernels with an oil extraction auxiliary agent, subjecting the mixture to microwave treatment, and then grinding the mixture into a slurry; mixing the slurry with water and pectinase, extracting the mixture, and centrifuging to obtain a first oil phase and an emulsion phase; standing and freezing the emulsion phase for demulsification, and then centrifuging to obtain a second oil phase, and combining the first oil phase and the second oil phase to obtain camellia oil; the oil extraction auxiliary agent is NaCl and NaHCO 3 .

[0006] The enzymatic processing technology of the present invention is a low-consumption and high-efficiency processing technology. By using an oil extraction auxiliary agent and microwave pretreatment before grinding, it is beneficial to reduce the formation of emulsion in the subsequent enzymatic extraction process. The process of the present invention reduces the amount of emulsion from the source, effectively solving the technical problem of severe emulsification. At the same time, by efficiently degrading the cell wall through domestic pectinase, it can promote the large-scale release of oil in the camellia seed kernel, greatly improve the quality and yield of oil and by-products, thereby reducing production costs and realizing enzymatic oil extraction of camellia seeds and high-value utilization of by-products.

[0007] In some embodiments, the total oil content is greater than 90%.

[0008] In some embodiments, the retention rate of nutrients is above 70%.

[0009] In some embodiments, the amount of NaCl added is 0.5% to 2% of the mass of the camellia oleifera seed kernel, preferably 0.8% to 1.2%.

[0010] In some embodiments, NaHCO 3 The added amount is 0.05% to 0.5% of the mass of the camellia seed kernel, preferably 0.08% to 0.12%.

[0011] In some embodiments, the microwave treatment is performed at 800-1200 W for more than 90 s, preferably at 800-900 W for 90-150 s.

[0012] In some embodiments, the crushing is performed three times or more, and after the first crushing, the product is sieved through a mesh of less than 2 mm; preferably, sieved through a mesh of 1-2 mm.

[0013] In some embodiments, the grinding is performed 2 to 4 times, preferably 4 times.

[0014] In some embodiments, the mass volume ratio of the slurry to water is 1 kg: 2~5 L, preferably 1 kg: 2.5~3.5 L.

[0015] In some embodiments, the pectinase is Xiasheng brand pectinase, preferably FFY-0654 plant extraction-specific or FDG-2259 pectinase with 300,000 enzyme activity.

[0016] In some embodiments, the amount of pectinase added is 1% to 1.25% of the mass of camellia oleifera seed kernel.

[0017] In some embodiments, the specific steps of the extraction include: mixing the slurry with water and pectinase, adjusting the pH to 3.5-5.5 (preferably 4.5-5.5), extracting at 40-60°C (preferably 55±3°C) for 1-8 h (preferably 2-4 h), and then inactivating the enzyme at above 80°C (preferably inactivating the enzyme at 80°C for 5-15 min).

[0018] In some embodiments, the centrifugal separation is performed by intermittent separation using a floor-standing centrifuge, or by continuous separation using a three-phase horizontal screw centrifuge or a disc centrifuge.

[0019] Preferably, the centrifugal speed is 4000-9000 rpm, preferably 4000-5000 rpm for intermittent separation and 6000-8000 rpm for continuous separation.

[0020] Preferably, the separation time is 30-40 min in intermittent separation, preferably 3 separations, each time for 10 min, and the continuous separation feed rate is 5-20 kg / min, preferably 10-15 kg / min.

[0021] In some embodiments, the processing technology further includes: after obtaining the camellia oil, extracting tea saponins from the residue phase using an ultrasonic-assisted deep eutectic solvent, and then drying the residue phase by microwaves to prepare detoxified feed; and spray drying the aqueous phase to obtain saccharide terpenoids.

[0022] Compared with the prior art, the present invention has the following beneficial effects: The invention provides a low-consumption and high-efficiency enzymatic processing technology for camellia oil. By screening domestic enzyme preparations, adding oil extraction aids before grinding and subjecting to microwave pretreatment, the dosage of water and enzyme is significantly reduced, the production cost is reduced, the formation of emulsion is effectively suppressed at the source, the subsequent de-emulsification process is simplified, the quality and yield of oil and by-products are greatly improved, and after a pilot test of 40-80 kg / batch of products, high-efficiency enzymatic oil extraction of camellia seeds and high-value utilization of by-products are achieved, the overall economic benefit and environmental sustainability of camellia oil processing are improved, and the invention provides a solid technical foundation for industrial production and comprehensive utilization of by-products under green enzymatic processing of camellia oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is the influence of centrifugal speed and centrifugal time on oil extraction rate.

[0024] Figure 2 It is the effect of crushing and grinding times on oil extraction rate.

[0025] Figure 3 It is the influence of oil extraction additives on the oil extraction yield.

[0026] Figure 4 It is the effect of microwave pretreatment on oil extraction rate.

[0027] Figure 5 It is the effect of enzyme preparations on oil extraction yield.

[0028] Figure 6 It is the main single factor affecting the oil extraction rate.

[0029] Figure 7 This is the process flow chart of the pilot production line. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution in the present invention will be described clearly and completely below. Obviously, the described embodiments are 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 creative work are within the scope of protection of the present invention. Except for Table 3, different lowercase letters in the same row in other figures and tables represent significant differences at the 0.05 level.

[0031] In the examples provided in this specification, if no specific techniques or conditions are specified, the techniques or conditions described in the literature in this field or the product instructions are used. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased through regular channels.

[0032] Example 1 Effect of centrifugal speed and centrifugal time on oil extraction rate The camellia oleifera seed kernel raw material was crushed three times by laboratory equipment, each time for 30 s, and 5.00 g of camellia oleifera seed kernel powder was passed through an 80-mesh sieve. At a solid-liquid ratio of 1:3.5 g / mL, Novozymes 3 pectinase (Table 1) was added at 1%, the pH was adjusted to 4.5, and the mixture was extracted at 50°C for 2 h, the enzyme was inactivated at 80°C for 10 min, and the mixture was centrifuged at 2000-12000 rpm for 10-60 min to separate the clear oil and the emulsion phase, and the clear oil rate was calculated. The emulsion phase was frozen at -18°C for 24 h, thawed at room temperature, and centrifuged at 8000 rpm for 20 min to separate the clear oil, and the total oil rate was calculated.

[0033] Experimental findings ( Figure 1), when the centrifugal speed increased from 2000 to 10000 rpm, the clear oil rate increased significantly, the latter was 1.25 times of the former, and then slightly decreased, but there was no significant difference; the total oil rate had two extremely high values ​​at the centrifugal speeds of 4000 and 10000 rpm, respectively. Although the latter was higher, the difference between the two was not significant. Considering the maximum speed of 5000 rpm of the laboratory intermittent separation centrifuge, 4000~5000 rpm was preferred for subsequent experiments. When the centrifugal time increased from 10 to 30 min, the clear oil rate and the total oil rate both increased rapidly, the latter was 1.33 and 1.13 times of the former, respectively, while from 30 to 50 min, the clear oil rate increased slightly and the total oil rate decreased slightly, but there was no significant difference. The subsequent experiment determined that the centrifugal time was 30 min, and it was actually centrifuged 3 times, each time for 10 min.

[0034] Example 2 Effect of crushing and grinding times on oil extraction yield The raw materials were crushed 1 to 4 times (passed through a 2 mm sieve after the first crushing) and ground 0 to 4 times by the pilot equipment to form a slurry. 100.00 g of the slurry was weighed, extracted at a solid-liquid ratio of 1:3.5 g / mL and 60°C for 2 h, centrifuged 3 times at 4000 rpm for 10 min each time, and the upper clear oil was collected to calculate the clear oil rate; the emulsion phase was frozen at -18°C for 24 h, thawed at room temperature, centrifuged 2 times at 4000 rpm for 10 min each time, and the clear oil was separated to calculate the total oil rate.

[0035] Depend on Figure 2 It can be seen that when only crushing without grinding, the clear oil rate and total oil rate are particularly low, but they increase significantly with the increase of crushing times, from 2.3% and 10.7% when crushing once to 43.3% and 52.4% when crushing four times, respectively, an increase of about 41%. In terms of the number of crushing, the clear oil rate and total oil rate both increase significantly with the number of grinding times, with only a few exceptions. During the entire experiment, the clear oil rate and total oil rate were the highest when crushing three times and grinding four times, which were 85.2% and 88.7% respectively, and the difference between the two was only 3.5%, indicating that the milk content under this state is also the lowest, so crushing three times and grinding four times was selected for the experiment.

[0036] Example 3 Effects of oil extraction additives and microwave pretreatment on oil extraction yield In order to reduce the emulsification phenomenon from the source, oil extraction additives and microwave pretreatment experiments were carried out. The raw material of camellia oleifera kernel was crushed three times by pilot equipment (after the first crushing, it was sieved with a 2 mm sieve), and 0%~3% NaCl and 0~0.5% NaHCO were added. 3 The oil extraction aid was microwaved at 0-1200 W for 90-150 s at a spreading thickness of 2 cm, and then ground 4 times into a slurry. Other steps were the same as in Example 2.

[0037] Figure 3 The results show that as the amount of NaCl added increases from 0% to 1%, the clear oil rate and total oil rate both increase significantly, and then decrease rapidly from 1% to 3%, and at 3%, they are only 90.1% and 98.6% of those at 0%, respectively, indicating that the appropriate amount of NaCl added can increase the oil extraction rate, but at a higher amount, it reduces the oil extraction rate. 3 With the increase of the addition amount, although the total oil rate reaches the highest value at 0.1%, the oil clearance rate decreases significantly, reaching the lowest at 0.2%, which is only 85.2% of 0%. Therefore, when the two oil extraction additives are used alone, 1% NaCl or 0.1% NaHCO 3 On this basis, 1% NaCl was fixed and different proportions of NaHCO were added. 3 , considering the oil extraction effect of the combined use of two oil extraction additives. The results showed that 1% NaCl + 0.1% NaHCO 3 Used together, it has the highest oil clearance rate and total oil rate, followed by NaHCO 3 The increase in NaHCO 3 Only when used in lower amounts can better oil extraction auxiliary effects be achieved.

[0038] Depend on Figure 4 It can be seen that at microwave powers ranging from 0 to 1200 W, both the clear oil rate and the total oil rate increased significantly with the increase of power, reaching the highest at 1200 W and 800 W, which were 1.15 and 1.12 times of that at 0 W, respectively, and decreased significantly at 1600 W. In terms of microwave time, the clear oil rate and the total oil rate were the highest at 90 to 150 s, and then decreased significantly, with the total oil rate decreasing more significantly.

[0039] Finally, we designed a composite oil extraction agent and microwave pretreatment and found that 1% NaCl+0.1% NaHCO 3 The oil removal rate and total oil rate of the treatment with 1% NaCl + 800 W 90 s were the highest, reaching 73.6% and 85.0%, respectively. The treatment with 1% NaCl + 800 W 90 s was the second highest, while the treatment with 0.1% NaHCO 3 + 800 W 90 s was the lowest, indicating that different combinations of oil extraction additives and microwave pretreatment had a significant effect on the oil extraction rate of camellia oil. The subsequent optimal solution was 1% NaCl + 0.1% NaHCO 3 + 800 W 90 s Combo.

[0040] Example 4 Effect of enzyme preparation on oil extraction yield The raw material of camellia oleifera kernel was crushed 3 times (passed through a 2 mm sieve after the first crushing) and ground 4 times by a pilot plant to form a slurry. 100.00 g of the slurry was weighed, and 1% of 9 brands of pectinase (Table 1) were added at a solid-liquid ratio of 1:3.5 g / mL, extracted at an optimal pH and temperature for 2 h, and inactivated at 80°C for 10 min. Others were the same as in Example 2.

[0041] Table 1 Specific parameters of enzyme preparations used

[0042] Experimental findings ( Figure 5 ), the oil clearance rate of the control group (CK) without enzyme was the lowest, only 55.6%, while Xiasheng 2 had the highest oil clearance rate, reaching 88.6%, followed by Novozymes 3 and Xiasheng 5, also reaching more than 85%. The total oil rates of Novozymes 1 and Xiasheng 2 were the lowest and highest (76.6% vs 90.4%), respectively, followed by Xiasheng 5 and Novozymes 3, reaching more than 86%, indicating that Xiasheng 2 and Xiasheng 5 can be used as domestic substitutes for Novozymes 3 enzyme preparations. Taking the prices on the scientific research materials management platform as an example (https: / / www.cassbuy.com), the average price of Novozymes 3 is 482.4 yuan / 50 mL (336-630 yuan / 50 mL), Xiasheng 2 and Xiasheng 5 are 150 yuan / kg and 875 yuan / kg respectively. Calculated based on the enzyme addition amount of 1.25%, the minimum production amount is 40 kg / batch, and each batch requires 0.5 kg of enzyme. The enzyme preparation alone can reduce the cost by 2337 yuan and more than 1974.5 yuan respectively (50 mL of Novozymes 3 is approximately calculated as 50 g).

[0043] Example 5 Effect of main single factor on oil extraction yield The oil-tea camellia kernel raw material was crushed 3 times (passed through a 2 mm sieve after the first crushing) and ground 4 times by a pilot plant to form a slurry. Weigh 100.00 g of the slurry, add 0.5% to 2% Xiasheng No. 2 pectinase, adjust the pH to 3.5 to 5.5, extract at 40 to 60°C for 1 to 8 h, and inactivate the enzyme at 80°C for 10 min. Other conditions were the same as in Example 2.

[0044] Figure 6 The results show that as the solid-liquid ratio increases from 1:2 to 1:3.5, the clear oil rate and total oil rate both reach the highest point, which are 1.33 and 1.10 times of that at a solid-liquid ratio of 1:2, respectively, and decrease significantly at a solid-liquid ratio of 1:4. The preferred solid-liquid ratio is 1:3.5, which can obtain the highest clear oil rate and total oil rate at the same time. If only the total oil rate is considered, the solid-liquid ratio can be expanded to 1:2.5-3.5, because within this solid-liquid ratio range, there is no significant difference in the total oil rate.

[0045] In terms of enzyme dosage, the changes in clear oil rate and total oil rate tend to be consistent. As the enzyme dosage increases from 0.5% to 1.25%, the content increases significantly. The latter is 1.27 and 1.31 times of the former, respectively. Then it decreases significantly. When the enzyme dosage is 2%, it is only 1.17 and 1.16 times of that when the enzyme dosage is 0.5%, respectively. Therefore, the preferred enzyme dosage is 1%~1.25%.

[0046] In terms of pH value, the clear oil rate and total oil rate at high pH (4.5-5.5) were significantly higher than those at low pH (3.5-4), with little difference overall (86.8%-88.6% vs 80.7%-81.3% and 89.2%-90.4% vs 80.9%-81.6%), but there was no significant difference within their respective ranges, so pH 4.5-5.5 was preferred.

[0047] In terms of extraction temperature, the clear oil rate and total oil rate have different changing trends. For example, the clear oil rate is the highest at 45℃, decreases at 50℃, and then increases again, while the total oil rate increases significantly with increasing temperature, but there is no significant difference in the respective ranges of 45~50℃ and 55~60℃. However, compared with other single factors, the clear oil rate and total oil rate ranges are the highest (88.6%~91.8% and 88.7%~93.3%). Considering that the activity of enzyme is greatly affected by temperature, 55±3℃ is preferred.

[0048] The extraction time had different changing trends from other factors. Within 1-4 h, the clear oil rate increased slowly, but there was no significant difference between them. It decreased significantly at 6-8 h, while the total oil rate had no significant difference within 1-8 h. Considering the energy consumption of heating and stirring during the extraction time, 2-4 h was selected in the subsequent period.

[0049] Example 6 Optimization of enzymatic orthogonal test On the basis of single factor experiment, we further optimized the enzymatic oil extraction process through orthogonal experiment, and selected solid-liquid ratio (A), enzyme dosage (B), pH value (C) and extraction temperature (D) as the investigation factors. Each factor was set with 3 levels (Table 2). The oil clearance rate and total oil rate were used as evaluation indicators, and the optimal process conditions were determined by range analysis. From the orthogonal experiment results in Table 2, it can be seen that the influence of the four factors on the oil clearance rate and the total oil rate is: A>D>B>C and B>A>D>C, indicating that the two evaluation indicators have a large difference in the influence of each factor. For the oil clearance rate, the solid-liquid ratio is the main influencing factor, followed by the extraction temperature and the enzyme dosage, and the pH value has the least effect; for the total oil rate, the enzyme dosage is the main influencing factor, followed by the solid-liquid ratio and the extraction temperature, and the pH value has the least effect. However, the optimal combination of the two is consistent, both are A 2 B 2 C 1 D 3The optimal process conditions obtained were: solid-liquid ratio 1:3 (g / mL), enzyme addition amount 1.25%, pH value 4.5, and extraction temperature 55°C.

[0050] Table 2 Orthogonal experimental design and results of enzymatic oil extraction

[0051] Example 7 Enzyme method verification test We verified the optimal process conditions obtained by orthogonal optimization, and added oil extraction additives and microwave pretreatment conditions. By comparing No. 1 to No. 4 in Table 3, it was found that before adding oil extraction additives, No. 3 and No. 2 obtained the highest oil clearance rate and total oil rate, reaching 88.7% and 92.0%, respectively, and No. 2 was consistent with the orthogonal test results. On the basis of No. 3, oil extraction additives were added. Except for a slight increase in the total oil rate of No. 7, the oil clearance rate and total oil rate of other conditions decreased slightly, but there was no significant difference compared with No. 3. After adding microwave pretreatment again, the oil clearance rate and total oil rate increased slightly, and No. 8 had a better effect than No. 9, with its oil clearance rate and total oil rate reaching 89.8% and 92.9%, respectively, indicating that 0.1% NaHCO 3 Relative to 0.2% NaHCO 3 , which can better cooperate with NaCl and microwave pretreatment, and is conducive to the dissolution of camellia oil in the process of aqueous enzymatic oil production. On the basis of No. 2, adding oil extraction additives and microwave pretreatment, the clear oil rate and total oil rate were slightly reduced, but there was no significant difference compared with No. 8. From the difference between the total oil rate and the clear oil rate, the difference of No. 9 was only 1.3%, indicating that oil extraction additives and microwave pretreatment can improve the clear oil rate and total oil rate of enzymatic camellia oil, and can significantly reduce the emulsification amount, which provides the possibility of reducing demulsification operations.

[0052] Table 3 Enzyme method validation

[0053] Example 8 Pilot Line Design and Verification The raw material of camellia kernel was crushed three times by pilot equipment (after the first crushing, it was sieved with 2 mm sieve), with or without the addition of oil extraction aids and microwave pretreatment, and then ground four times into slurry. The solid-liquid ratio was 1:2.5~3.5 kg / L, the amount of Xiasheng No. 2 enzyme was 1%~1.25%, pH 4.5, and the extraction was carried out at 55±3℃ for 4 h. The enzyme was inactivated at 80℃ for 10 min, and the mixture was separated continuously by a three-phase horizontal screw centrifuge or a disc centrifuge at a feed rate of 10~15kg / min. The oil emulsion phase was subjected to static stratification, frozen demulsification, and vacuum dehydration to obtain camellia seed oil; the residue phase was subjected to ultrasonic-assisted deep eutectic solvent extraction of tea saponin, and then microwave drying to prepare detoxified feed; the aqueous phase was spray-dried to obtain saccharoterpenoids. The process flow chart of the pilot line is shown below: Figure 7 shown.

[0054] Considering the actual capacity of the pilot line enzymatic hydrolysis tank of 300 L, the oil content of camellia kernel was used as the calculation basis, and batch production was carried out according to the optimized combination parameters. In order to cover different solid-liquid ratios, the pilot verification was carried out three times. The main parameters of the first test were: 40 kg of camellia kernel raw material, solid-liquid ratio of 1:3.5, enzyme addition amount of 1.25%, pH 4.5, 55±3℃ 3.5 h; the main parameters of the second test were: 60 kg of camellia kernel raw material, oil extraction additive (1% NaCl + 0.1% NaHCO 3 ), microwave pretreatment (800 W 90 s), solid-liquid ratio 1:3, enzyme addition amount 1%, pH 4.5, 55±3℃ 4 h; the third main parameters: 80 kg of camellia kernel raw material, addition of oil extraction additives (1% NaCl + 0.1% NaHCO 3 ), solid-liquid ratio 1:2.5, enzyme addition amount 1.25%, pH 4.5, 55±3℃ 4 h. The total oil rates of camellia oil obtained in the three pilot productions were 91.3%, 92.8% and 91.7% respectively.

[0055] Example 9 Nutritional Quality Evaluation 1. Nutritional components of camellia oil We further analyzed the nutritional components of the obtained camellia oil and compared it with the company's production line and two commercially available oils. Among them, W1, company production line; W2, Example 7, No. 2; W3, Example 7, No. 10; W4, pressing (50℃ hydraulic pressure for 1h); W5, commercially available 1 (a water-enzyme oil from a company in Anhui); W6, commercially available 2 (a water-enzyme oil from a company in Jiangxi).

[0056] As shown in Table 4, except for the acid value of sample W1 from the enterprise production line, which reaches the crude oil standard compared with GB / T 11765, the acid value and peroxide value of other samples reach the first-level standard of the water enzyme method, and the peroxide value of our enzymatic method W2~W3 camellia oil is lower than that of the pressed camellia oil W4. The fatty acid composition of all samples is within the standard requirements. The linoleic acid in our samples is slightly higher than that of the enterprise production line samples (8.1%~8.2% vs 7.8%), while the palmitic acid is slightly lower (8.5%~8.6% vs 8.8%). On this basis, our samples have a higher content of unsaturated fatty acids (89.0%~89.1% vs 88.6%), which is equivalent to the pressing method (89.1%). In terms of triglyceride composition, OOO accounted for the highest percentage (59.2%~65.1%), followed by SOLi and OOLi, accounting for 19.2%~19.6% and 9.4%~11.6% respectively. The OOO and SOLi of the two commercially available oils were higher than our W3 samples, while OOLi was lower than our samples. The W1 samples from the company's production line were not much different from our samples.

[0057] In terms of nutritional ingredients, the total polyphenol content of our W3 sample (19.9 mg / kg) is higher than that of the enterprise production line (17.3 mg / kg) and commercial oil (10.6~14.4 mg / kg), but slightly lower than that of the pressed oil (21.0 mg / kg), and squalene has a similar change pattern. The total amount of tocopherol and tocotrienol in the commercial oil is higher, reaching 210.9~308.5 mg / kg, followed by the pressing method and our samples, which are 185.3~195.4 mg / kg, while the sample of the enterprise production line has the lowest content, only 161.5 mg / kg, mainly from the contribution of α-tocopherol. However, the total amount of sterols in the commercial oil is the lowest, at 471.2~522.8 mg / kg, which is only 41.0%~45.5% of the highest value of 1149.7 mg / kg in our W3 sample, mainly due to the difference in the composition of Δ7-stigmasterol, β-sitosterol, cholesterol and erythrostosterol.

[0058] Table 4 Basic physical and chemical indicators and nutritional components of camellia oil

[0059] 2. Nutritional composition of camellia oil cake Finally, we compared the basic nutritional components in the oil-making tea cake after oil extraction and compared it with the pressing method. The retention rate / %=(100-crude fat in the raw material)%×the content of this component in the cake / the content in the raw material. Among them, W1, enterprise production line; W2, serial number 2 of Example 7; W3, serial number 10 of Example 7; W4, pressing (hydraulic pressing at 50℃ for 1 h); W5, W4+oil extraction additive (1%NaCl+0.1% NaHCO 3 ) + microwave pretreatment (800 W 90 s).

[0060] As shown in Table 5, the moisture content of the enzyme method and the pressing method after adding oil extraction additives + microwave pretreatment was slightly higher than that before addition (9.3% vs 8.7% and 8.2% vs 7.5%), but there was no significant difference between them. The change of crude fat was just the opposite, and it was the lowest in the enzyme method (5.5%~5.6%), indicating that the enzyme method obtained a higher oil extraction rate. The crude protein content of the pressing method was significantly the highest, while the crude fiber was the lowest in the pressing method and the highest in the enzyme method (4.3%~4.7% vs 2.2%), with a difference of about 2 times. The total polysaccharide was the lowest in the pressing method W5 and the enterprise production line (5.1%~5.7%), and the other change trends were similar to those of crude fat.

[0061] We further compared and calculated the nutritional components of the camellia kernel raw materials before oil extraction and the camellia cake after oil extraction, and obtained the retention rate of each major nutrient after oil extraction (Table 6). The results showed that the change trend of crude protein, crude fiber and total polysaccharides was generally the same as that of cake, such as the highest crude protein retention rate (>89%) and the lowest crude fiber retention rate (<38%) in the pressing method, while the retention rate of the enzyme method was more stable, with all three parameters greater than 72%, the highest reaching 84.7%, and the enterprise production line was slightly lower.

[0062] Table 5 Basic physical and chemical indicators and nutritional components of camellia oleifera cake (dry matter)

[0063] Table 6 Nutritional retention rate of tea oil cake

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An enzymatic processing technology for camellia oil, characterized in that: include: The crushed camellia oil seed kernels are mixed with an oil extraction aid, subjected to microwave treatment, and then ground into a slurry; The slurry is mixed with water and pectinase for extraction, and a first oil phase and an emulsion phase are obtained after centrifugal separation; the emulsion phase is allowed to stand and is frozen to break the emulsion, and then centrifuged to obtain a second oil phase, and the first oil phase and the second oil phase are combined to obtain camellia seed oil; the oil extraction auxiliary agent is NaCl and NaHCO3.

2. The processing technology according to claim 1, characterized in that: The amount of NaCl added is 0.5% to 2% of the mass of the camellia oleifera kernel, preferably 0.8% to 1.2%.

3. The processing technology according to claim 1, characterized in that: The amount of NaHCO3 added is 0.05% to 0.5% of the mass of the camellia oleifera seed kernel, preferably 0.08% to 0.12%.

4. The processing technology according to claim 1, characterized in that: The microwave treatment is performed at 800-1200 W for more than 90 s, preferably at 800-900 W for 90-150 s; And / or, the number of times of pulverization is more than 3 times, and after the first pulverization, the product is sieved through a mesh of less than 2 mm; preferably, sieved through a mesh of 1-2 mm; And / or, the grinding is performed 2 to 4 times, preferably 4 times.

5. The processing technology according to claim 1, characterized in that: The mass volume ratio of the slurry to water is 1 kg:2~5 L, preferably 1 kg: 2.5~3.5 L.

6. The processing technology according to claim 1, characterized in that: The pectinase is Xiasheng brand pectinase, preferably FFY-0654 plant extraction-specific or FDG-2259 pectinase with 300,000 enzyme activity.

7. The processing technology according to claim 6, characterized in that: The added amount of pectinase is 1% to 1.25% of the mass of camellia oleifera seed kernel.

8. The processing technology according to claim 1, characterized in that: The specific steps of the extraction include: mixing the slurry with water and pectinase, adjusting the pH to 3.5-5.5, preferably 4.5-5.5, extracting at 40-60°C for 1-8 h, preferably extracting at 55±3°C for 2-4 h, and then inactivating the enzyme at above 80°C, preferably inactivating the enzyme at 80°C for 5-15 min.

9. The processing technology according to claim 1, characterized in that: The centrifugal separation is performed by intermittent separation using a floor-standing centrifuge, or continuous separation using a three-phase horizontal screw centrifuge or a disc centrifuge; The centrifugal speed is 4000-9000 rpm, preferably 4000-5000 rpm for intermittent separation and 6000-8000 rpm for continuous separation; The separation time is 30-40 min in intermittent separation, preferably 3 separations, each time for 10 min, and the continuous separation feed rate is 5-20 kg / min, preferably 10-15 kg / min.

10. The processing technology according to claim 1, characterized in that: Also includes: After the camellia oil is obtained, the residue phase is subjected to ultrasound-assisted deep eutectic solvent extraction of tea saponin, and then subjected to microwave drying to prepare detoxified feed; The aqueous phase was spray-dried to obtain saccharide terpenoids.

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