Preparation method of high-resveratrol peanut oil

Abstract

The invention discloses a preparation method of high-resveratrol peanut oil, and belongs to the technical field of edible oil processing. The method comprises the following steps: pretreating peanuts and peanut root powder; the solubility saturation value of resveratrol in squeezed crude oil is measured, the target content is set, and the adding proportion of the peanut root powder is accurately determined by measuring the resveratrol dissolution concentration of the treated peanut root powder under a preset extraction process and combining the residual oil mass of the peanut cake meal; mixing the peanut cake meal with the treated peanut root powder in proportion to obtain a mixed raw material; carrying out extraction operation of at least two polarity increasing stages on the mixed raw material; and finally, carrying out solid-liquid separation and desolventizing treatment on the leached mixture to obtain the high-resveratrol peanut oil. According to the method, the resveratrol is efficiently and stably enriched in the peanut oil through accurate material ratio and gradient extraction, and technical support is provided for development of high-value-added functional peanut oil products.

Description

Technical Field

[0001] This invention relates to the field of edible oil processing technology. More specifically, this invention relates to a method for preparing high-resveratrol peanut oil. Background Technology

[0002] Resveratrol, a natural active ingredient with significant health benefits, represents a key technological direction for the efficient and stable enrichment of in edible oils in the development of functional oils. Current technologies for preparing high-resveratrol peanut oil by mixing and extracting resveratrol-rich peanut root powder with peanut meal containing residual oil mainly face the following interrelated technical bottlenecks: First, in terms of differentiated and synergistic pretreatment of raw materials, there is a contradiction between achieving high extraction efficiency and preserving activity. Peanuts and peanut roots have vastly different physical properties: peanuts require pretreatment to improve pressing characteristics and protect oil quality; peanut roots require thorough cell disruption to release intracellular resveratrol, but this component is heat-sensitive. Existing methods often employ similar or single pretreatment methods (such as conventional microwave or ultrasonic treatment) for both, making simultaneous optimization difficult. For peanuts, continuous microwave treatment can easily lead to localized overheating, triggering oil oxidation; for peanut root powder, increasing the treatment intensity to improve extraction rate (such as increasing ultrasonic power or extending microwave time) makes it difficult to avoid localized temperature rise in the material, leading to the degradation of heat-sensitive resveratrol. The fundamental reason is the lack of a physical field synergistic pretreatment strategy that can differentiate and refine pretreatment based on material characteristics and provide real-time temperature control.

[0003] Secondly, there is a lack of quantitative models for determining the proportion of active ingredient fortification sources, moving from "empirical estimation" to "precise design." To achieve stable and controllable resveratrol content in finished oil products, the amount of exogenous peanut root powder added must be precisely calculated. This calculation must simultaneously meet two core boundaries: first, the target concentration of the finished oil must not exceed the solubility saturation value of resveratrol in that batch of base oil to prevent precipitation; second, the total amount of resveratrol that can be extracted from the added root powder by the actual process should be precisely dissolved and carried by the residual oil contained in the oil cake. Existing methods mostly rely on fixed formulas or rough experience, failing to establish a quantitative calculation model that correlates the target concentration, the solubility capacity of the carrier oil (solubility saturation value), the actual dissolution capacity of the raw material after specific pretreatment, and the process transfer efficiency. Because the pretreatment process significantly affects the dissolution rate, and the residual oil rate of different batches of oil cake fluctuates, the finished product content varies greatly between production batches relying on fixed proportions, resulting in poor stability.

[0004] Third, the core enrichment and separation processes present a complex challenge in terms of extraction adequacy, selectivity, and protection of active ingredients. In the extraction stage, to achieve full transfer of the target component from root powder to the oil carrier, multi-stage extraction using solvents with increasing polarity is necessary. However, traditional methods are prone to fluctuations in temperature and concentration during solvent switching, potentially leading to re-dissolution of already dissolved resveratrol or incomplete extraction, affecting the final enrichment efficiency and batch stability. Furthermore, the extraction endpoint often depends on a fixed time, making it difficult to adapt to differences in raw materials with varying pretreatment levels. In the desolventizing stage, the key challenge lies in ensuring that while completely removing industrial solvents to meet safety standards, subsequent changes in solvent composition and the relative concentration of resveratrol can prevent oxidation, degradation, or isomerization due to continuous heating. Conventional single-condition desolventizing operations lack a mechanism for dynamic adjustment based on the desolventizing process, making it difficult to achieve an optimal balance between thorough removal and active ingredient retention.

[0005] In summary, existing technologies for preparing high-resveratrol peanut oil have significant shortcomings in areas such as differentiated and precise pretreatment of raw materials, scientific quantitative calculation of active ingredient addition, and dynamic optimization control of the enrichment and separation process, which restrict the efficient, stable, and standardized production of the product. Therefore, there is an urgent need to develop a novel integrated preparation method to systematically solve the above problems. Summary of the Invention

[0006] One object of the present invention is to provide a method for preparing high resveratrol peanut oil, which can obtain peanut oil products with significantly increased resveratrol content.

[0007] To achieve these objectives and other advantages of the present invention, according to one aspect of the present invention, a method for preparing high-resveratrol peanut oil is provided, comprising the following steps: Step 1: Take peanut root powder and subject it to segmented ultrasonic treatment and microwave treatment in sequence. The segmented ultrasonic treatment includes at least two stages with different power or modes, and the material temperature is controlled during the treatment. Take peanuts and microwave them, then press them to obtain crude oil and peanut cake containing 8-12% residual oil. Step 2: Determine the solubility saturation value S of resveratrol in the pressed crude oil, and set the resveratrol content Co of the target finished oil, where Co = k × S, and k is a coefficient of 0.5~0.95; Based on Co and S, determine the addition ratio of peanut root powder in the mixed raw materials in the following way: Measure the resveratrol dissolution concentration Ce of the peanut root powder treated in Step 1 under the preset extraction process; based on material balance, calculate the required root powder mass W according to the target concentration Co, residual oil mass Mo, dissolution concentration Ce, and solvent volume Vs, and determine the addition ratio P accordingly; then mix the peanut cake and the peanut root powder treated in Step 1 according to the calculated addition ratio to obtain the mixed raw materials; Step 3: Use a series extraction system to extract the mixed raw materials. The extraction operation includes at least two stages, and the polarity of the extraction solvent used in the subsequent stages is higher than that in the previous stage. Step 4: Perform solid-liquid separation on the extracted mixture to obtain a supernatant. Perform solvent removal treatment on the supernatant. The solvent removal treatment includes: a first stage to remove most of the solvent under vacuum conditions; a second stage when the ethanol content in the distillate exceeds 80% of the total solvent mass, switching to a protection stage with lower absolute pressure (higher vacuum degree) and lower temperature to continue solvent removal until the solvent residue meets the standard, thereby obtaining the high resveratrol peanut oil.

[0008] The above method constructs an integrated process chain that combines resource synergy and precise process control. Its core lies in: systematically using peanut oil-containing cake after pressing as a lipid carrier, and combining it with peanut root powder treated by segmented ultrasound and microwave as an exogenous fortifier, thus achieving functional coupling and high-value utilization of processing by-products; abandoning the traditional empirical addition method, a calculation model was established with the target product concentration (Co), carrier oil solubility (solubility saturation value S), and actual raw material dissolution rate (dissolution concentration Ce) as core parameters. By setting Co=k×S (k=0.5~0.95), while pursuing high content, a safety margin was reserved for process fluctuations and storage stability, fundamentally avoiding the problems of resveratrol precipitation and product turbidity during storage caused by excessive addition. By scientifically determining the addition ratio based on the residual oil quality (Mo) of the oil cake, a fundamental shift from "experience-based addition" to "quantitative design" has been achieved. In terms of process, by performing extraction operations on the mixed raw materials in at least two polarity-increasing stages, the target components have been efficiently and directionally transferred and enriched from root powder to the oil matrix.

[0009] The method for determining the solubility saturation value (S) of resveratrol in crude pressed oil is as follows: Take the crude pressed oil prepared in this batch, and first centrifuge to remove trace solid impurities to obtain a clear oil sample as the solvent medium. Weigh an excess (usually 2-3 times the predicted solubility) of pure resveratrol standard and add it to a known mass (e.g., 10.00 g) of the above-mentioned crude pressed oil. Place the mixture in a constant-temperature shaker and shake at a suitable speed (e.g., 150 rpm) in the dark at 25°C. Continue shaking for a sufficient time (usually 24-48 hours) to ensure that dissolution reaches equilibrium. Subsequently, centrifuge the mixture at the same temperature at high speed (e.g., 10000 rpm, 20 min), or filter it using a 0.22 μm organic phase filter membrane to completely separate undissolved resveratrol solids and obtain a clear saturated oil solution. Accurately weigh a certain mass of the saturated oil solution and quantitatively determine the concentration of resveratrol using high-performance liquid chromatography (HPLC). To ensure accuracy, multiple parallel experiments can be performed. The resveratrol concentration measured after equilibrium is reached is the solubility saturation value S of resveratrol in this batch of crude pressed oil at the experimental temperature, usually expressed in mg / kg.

[0010] Additionally, k is a pre-defined safety factor, with a value range limited to 0.5 to 0.95. This range is set based on a comprehensive trade-off between product functionality, stability, and process robustness, for the following reasons: The upper limit of 0.95 is set to provide a safety margin to prevent precipitation during storage, ensuring that the actual concentration (Co) of resveratrol in the finished oil is always significantly lower than its immediate theoretical saturation point (S) in the oil, thus providing a safety margin for potential fluctuations in conditions during storage, transportation, and use. The lower limit of 0.5 is set to guarantee the product's functional value and commercial viability. It ensures that the finished oil has a significantly increased resveratrol content, thereby possessing clear functional claim value and market competitiveness. If the k value is too low (e.g., <0.5), the absolute resveratrol content (Co) in the finished oil may have limited improvement. Setting the lower limit of k to 0.5 ensures that each unit of edible oil provides a meaningful intake of resveratrol. This value range resolves the contradiction between "pursuing high content" and "preventing precipitation during storage."

[0011] Preferably, the microwave treatment process of peanuts in step one is as follows: Spread the peanuts evenly on a microwave-safe tray with a layer thickness of 2-4 cm, place them in a microwave device, and process them under microwave power of 2-4 kW. The microwave processing is carried out in an intermittent and segmented manner, specifically: after each continuous processing for 3-5 minutes, pause for 1-2 minutes, with a total microwave processing time of 10-20 minutes. After the microwave processing is completed, allow the peanuts to cool naturally to room temperature.

[0012] The above steps utilize the volumetric heating effect of microwaves to rapidly heat the internal moisture and oil of peanuts, loosening the cell structure and increasing oil fluidity, thus facilitating subsequent pressing and oil extraction. Simultaneously, forced intermittent operation, with pauses inserted between microwave radiation segments, provides time for even heat transfer to the material's interior and avoids localized high temperatures caused by continuous heating. Specific parameters were designed for the peanut material, including layer thickness, microwave power, and an intermittent rhythm of "3-5 min processing - 1-2 min pause" with a total duration of 10-20 min. This combination of parameters constitutes an optimized processing regime that effectively promotes oil extraction while significantly reducing the risk of oxidative deterioration due to heat accumulation, thereby achieving a balance between improving efficiency and ensuring the quality of the base oil.

[0013] Preferably, the segmented ultrasonic treatment process of peanut root powder in step one is as follows: The first stage involves continuous treatment with an ultrasonic power of 200-400 W for 5-10 minutes. The second stage uses an ultrasonic power of 300-400 W and is treated in an intermittent mode for 5-10 minutes. The working cycle of the intermittent mode is 30 seconds of ultrasonic treatment followed by a 15-second interval. The third stage involves continuous treatment with ultrasonic power of 150~300 W for 3~5 minutes; During the segmented ultrasonic treatment process, the material temperature is monitored in real time. When the material temperature exceeds 65°C, the ultrasonic treatment is paused and air cooling is started. The ultrasonic treatment is resumed when the material temperature drops below 55°C.

[0014] The above steps employ a "stepped energy input and dynamic thermal management" strategy to progressively achieve physical cell disruption, enhanced mass transfer, and ultimately system stabilization: the first stage uses medium-to-high power continuous ultrasound to stimulate cavitation and initiate cell structure disruption; the second stage switches to a high-power intermittent mode, maintaining strong cavitation while preventing excessive energy accumulation through regular intermittent cycles, thus facilitating deeper material disruption and promoting component dissolution; the third stage switches to medium-to-low power continuous processing to gently complete the final extraction and promote the dispersion of released components. A systematic combination of specific power parameters, processing time, and a "continuous-intermittent-continuous" working mode constitutes an optimized energy application program. Simultaneously, a real-time monitoring and air-cooling linkage control mechanism based on a specific temperature threshold (pausing above 65℃ and resuming below 55℃) is introduced. This effectively avoids overheating caused by prolonged ultrasound processing while fully leveraging the mechanical effects of ultrasound to improve extraction efficiency, ensuring the stable activity of heat-sensitive target components.

[0015] Preferably, the microwave treatment process of the peanut root powder in step one is as follows: The ultrasonically treated peanut root powder is spread evenly on a microwave-specific support tray, with the layer thickness controlled between 1 and 3 cm, and then placed in a microwave device equipped with an infrared temperature sensor. Start microwave processing, with the initial power set to 2~3 kW and the target control temperature range set to 55~60℃; During microwave processing, an infrared temperature sensor monitors the surface temperature of the material in real time at 10-second intervals. When the material temperature is detected to be below 55℃, the microwave equipment operates continuously at a power of 3~4 kW. When the material temperature is detected to rise to between 55 and 60°C, the microwave equipment switches to pulse working mode, with its working power adjusted to 2 to 3 kW and a working cycle of 30 seconds on and 30 seconds off. When the material temperature is detected to exceed 60°C, the microwave equipment immediately stops heating and starts air cooling until the material temperature drops below 55°C, then heating is resumed according to the above rules. The total duration of the microwave processing is controlled within the range of 8 to 15 minutes.

[0016] This step utilizes the rapid volumetric heating characteristics of microwaves to provide a gentle follow-up treatment to root powder that has already undergone ultrasonic pretreatment. The aim is to further disrupt cell structure and promote component dissolution. Its core is precise closed-loop control of the heating process through real-time temperature feedback, ensuring that the bulk temperature of the material is consistently maintained within an effective and safe window of 55-60°C. The real-time monitoring signal from the infrared temperature sensor (intervals of 10 s) is dynamically and automatically linked to the microwave equipment's operating modes (continuous heating, pulse heating, heating stopped and air-cooled), with specific and clear control logic and parameters set: when the temperature is below 55°C, higher power (3-4 kW) is used for continuous operation to rapidly raise the temperature; when the temperature enters the target range, it automatically switches to a lower power (2-3 kW) pulse mode (30 s operation, 30 s interval) to maintain a constant temperature; once the temperature exceeds the safe upper limit of 60°C, heating is immediately stopped and forced air cooling is initiated. This microwave processing strategy, based on precise temperature control and automatic switching of multiple modes, achieves efficient processing while minimizing the risk of degradation of the heat-sensitive active ingredient resveratrol due to localized overheating.

[0017] In this invention, the pretreatment of peanut root powder employs a combination of segmented ultrasonic and microwave treatments. The temperature control parameters for both are not set independently but rather form a progressive and synergistic temperature control system to jointly ensure the activity of heat-sensitive resveratrol. The core of ultrasonic treatment lies in utilizing cavitation to break cell walls, with temperature control focusing on preventing localized instantaneous overheating. The core of microwave treatment lies in utilizing bulk heating to further promote component dissolution, with temperature control focusing on maintaining a uniform and suitable temperature overall. Ultrasonic treatment sets a pause threshold of 65°C to intercept any instantaneous high temperatures that may be generated by high-intensity ultrasound; its recovery threshold of 55°C provides a safe base temperature for the material to enter subsequent microwave treatment. Microwave treatment precisely sets the target temperature range to 55-60°C and maintains it using closed-loop control. Together, these methods ensure that the main temperature of the material throughout the pretreatment stage is effectively constrained within the optimal window of 55-60°C. This synergistic strategy of "ultrasonic overshoot prevention and microwave constant temperature maintenance" not only maximizes the destruction of cell structure and improves dissolution efficiency, but also systematically avoids the risk of degradation of heat-sensitive components that may be caused by improper treatment of a single physical field or inaccurate temperature control, laying a key foundation for the subsequent efficient enrichment of highly active resveratrol.

[0018] Preferably, the proportion of peanut root powder added to the mixed raw materials in step two is determined by the following method: The solubility saturation value S of resveratrol in the pressed crude oil was determined; the resveratrol content Co of the target finished high-resveratrol peanut oil was set, where Co = k × S, and k is a coefficient of 0.5 to 0.95. Weigh the peanut root powder processed in step one as a sample, with a mass of Ws (kg); perform an experimental extraction operation on the sample using a preset extraction process, with an extraction solvent volume of Vs (mL); perform solid-liquid separation on the mixture after experimental extraction to obtain an extract; determine the concentration of resveratrol Ce (mg / mL) in the extract. Obtain the mass Mc (kg) of the peanut meal obtained in step one; and calculate the mass of residual oil Mo = Mc × R based on its residual oil content R, where R ranges from 8% to 12%. Through formula Calculate the required peanut root powder mass W, kg; where η is the resveratrol process transfer coefficient preset based on historical production data, and its value range is 0 < η ≤ 1; Calculate the proportion P of peanut root powder in the mixed raw materials, P=W / (W+Mc).

[0019] This method for determining the addition ratio is based on precise material balance and dissolution equilibrium theory to achieve predictable and controllable resveratrol content in finished oil. Its core lies in constructing a quantitative calculation model that links the target product concentration, the solubility of the carrier oil, the actual dissolution performance of the raw materials, and the process transfer efficiency. First, by measuring the solubility saturation value S of resveratrol in crude pressed oil, a theoretical upper limit is set for the target resveratrol concentration Co in the finished oil, ensuring Co ≤ S to avoid precipitation during storage. Simultaneously, a proportionality coefficient k (Co = k × S, k = 0.5~0.95) is introduced to reserve a safety margin for process fluctuations while pursuing high content, balancing target specificity and robustness. Second, the actual dissolution capacity of peanut root powder after specific pretreatment is quantified through a pre-designed extraction experiment, and the dissolution concentration Ce is measured. This quantitative parameter truly reflects the comprehensive effect of complex pretreatment processes (ultrasound, microwave), incorporating raw material differences and pretreatment efficiency into the calculation system. Finally, the calculation model uses the mass Mo of residual oil contained in peanut cake as the matrix carrying the target component, and uses the formula... The required peanut root powder mass W is calculated by reverse calculation. This formula is derived from the following material balance: the total mass M of resveratrol that needs to be supplied by the root powder and ultimately dissolved in the finished oil is Co × Mo; and the mass of resveratrol that each gram of root powder can provide in the simulation experiment and is expected to transfer to the oil phase is (η × Ce × Vs) / Ws; dividing these two gives the required root powder mass W. The introduction of the process transfer coefficient η (0 < η ≤ 1) is crucial. It is preset based on historical production data to correct for systematic differences between ideal laboratory conditions and actual efficiency in large-scale production, making the model more engineering-guided. Finally, the mixing ratio is determined by P = W / (W + Mc).

[0020] Explanation of the process transfer coefficient η: In the aforementioned calculation model, the preset process transfer coefficient η is a key empirical parameter. Its physical essence reflects the overall transfer and loss efficiency of resveratrol from the predicted value of laboratory-simulated extraction to the final product in large-scale production. Theoretically, if Cr represents the actual resveratrol concentration detected in the final product and Co represents the preset target concentration, then η can be characterized as the ratio of the actual result to the theoretical target, i.e., η approaches Cr / Co. This ratio comprehensively covers the efficiency discounts caused by many factors such as production scale-up, differences in extraction kinetics, incomplete solid-liquid separation, heat-sensitive losses during desolventizing, and detection errors. It is a core indicator for evaluating the stability and reproducibility of the entire process chain.

[0021] However, in the computational model used to guide new batch production, η must be a pre-defined input value. Therefore, η is not determined by working backward from the results of the current batch production, but rather by pre-setting and calibrating based on historical production data or pilot-scale experiments. Specifically, by analyzing data from multiple previous production batches, a stable relationship is established between the simulated extraction concentration Ce, the calculated addition amount W, and the final product concentration Cr, thereby statistically deriving a representative range of η values ​​(e.g., 0.85~0.95). During initial production or significant adjustments to process conditions, a pilot-scale experiment is required, using the same complete process path as this invention, to directly calibrate the coefficient from the measured Cr to Co ratio. This method ensures that the η value embodies both the physical meaning of "target achievement rate" and the operability of serving as a pre-defined parameter to guide production, thus bridging laboratory measurement and large-scale production, and is a crucial guarantee for achieving precise control of product content.

[0022] This method completely abandons the traditional extensive model that relies on fixed formulas or empirical estimations, achieving a scientific leap from "experience-based judgment" to "quantitative design" in the addition ratio. By correlating the target concentration Co with the upper limit of solubility S and performing precise calculations based on the actual dissolution capacity Ce of the raw materials, it ensures from the source that the resveratrol content in the finished oil consistently reaches the preset target, significantly improving the consistency between production batches and the reliability of product quality. Simultaneously, this method achieves efficient utilization of the raw material (peanut root powder), avoiding insufficient or wasted active ingredients by precisely matching the addition amount with the residual oil carrying capacity. Furthermore, the model possesses good adaptability and guidance, responding to the natural differences between different batches of raw materials (different root powder dissolution rates Ce) and oilseed cakes (fluctuating residual oil rate R). Through dynamic adjustment of the ratio based on actual measurements of key parameters, it enhances the robustness of the entire process chain. Finally, this precise calculation model, organically combined with the aforementioned differentiated pretreatment and polar gradient extraction steps, constitutes a complete, precisely controlled technical solution, providing a core guarantee for the stable production of high-content, high-stability functional oil products.

[0023] Preferably, the extraction operation in step three is performed through a system consisting of a first extraction unit and a second extraction unit connected in series; each of the first and second extraction units includes an extraction tank, a circulating pump, and a heat exchanger; the specific steps of the extraction operation are as follows: All the mixed raw materials are loaded into the extraction tank of the first extraction unit; a first extraction solvent is injected into the extraction tank of the first extraction unit, the first extraction solvent being prepared by mixing No. 6 extraction solvent oil and ethanol at a volume ratio of 1:2 to 1:3; at the same time, a second extraction solvent is injected into the extraction tank of the second extraction unit, the second extraction solvent being prepared by mixing No. 6 extraction solvent oil and ethanol at a volume ratio of 1:3 to 1:4; Start the circulation pump of the first extraction unit to circulate the material in the first extraction unit between the extraction tank and the heat exchanger, maintain the temperature at 30~50℃, and the circulation flow rate is 4~7 times the effective volume of the extraction tank per hour, and circulate for 20~30 minutes; at the same time, start the circulation pump of the second extraction unit to circulate the second extraction solvent independently between the extraction tank and the heat exchanger of the second extraction unit, and maintain the temperature at 30~50℃ as well. After the first extraction unit completes the cyclic extraction, all the liquid in the extraction tank of the first extraction unit is pumped out and used as the extracted mixture for subsequent processing. Then, the preheated second extraction solvent in the extraction tank of the second extraction unit is pumped into the extraction tank of the first extraction unit, mixed with the mixed raw materials, and the above cyclic extraction steps are repeated for 20-30 minutes. After this extraction is completed, all the liquid in the extraction tank of the first extraction unit is pumped out and combined with the previously pumped liquid to form a mixture for further processing.

[0024] This step constructs a continuous extraction system with "serialized equipment and parallel operation." Its core is the parallel tasks of immediate extraction and solvent preheating, performed by two independent extraction units: the first unit uses a mixed solvent with lower polarity for the first extraction, while the second unit independently circulates and preheats the solvent with higher polarity for the second extraction. This transforms the "heating waiting time" necessary in typical sequential operations into a parallel, usable "effective preheating time." This equipment layout and process design eliminates the solvent switching gaps that are unavoidable in traditional multi-stage extraction processes, ensuring that the solvent is at its optimal operating temperature at the start of the second extraction. This significantly improves overall process efficiency and thermal energy utilization, and by maintaining a stable temperature in the extraction system, it ensures the consistency of extraction results and the stability of the active ingredient dissolution process.

[0025] Preferably, the extraction process preset in step two is consistent with the extraction operation in step three.

[0026] The pre-set extraction process in Step Two (calculating the addition ratio) is consistent with the extraction operation in Step Three (actual production). Its design principle lies in constructing a "deviation-free process mapping bridge between the experimental and production scales." The core of this method is that the experimental extraction used to obtain the key calculation parameter—the resveratrol dissolution concentration (Ce) of peanut root powder—must be completely consistent with the extraction operation used in subsequent large-scale production in all key process conditions, including solvent system, temperature, mixing method, and even equipment operating mode. This consistency ensures that the Ce value measured from the small-scale sample can truly and directly reflect the dissolution behavior of a specific batch of peanut root powder in the subsequent actual production extraction unit. Therefore, the peanut root powder addition ratio (W) calculated based on the Ce value has high predictive accuracy and production guidance value. It eliminates systematic errors introduced by differences between laboratory and production line conditions, allowing the precise calculation model established in Step Two to be built on a reliable data foundation.

[0027] This fundamentally ensures the accuracy and effectiveness of the aforementioned calculation model, transforming "quantitative design" from a theoretical model into a reproducible production practice. It is a key support for ensuring that the resveratrol content in the finished oil product accurately reaches the preset target (Co). Secondly, it significantly improves the robustness and repeatability of the entire process. Different batches of raw materials can obtain their own specific Ce values ​​tailored to the production line simply through this standardized "simulated extraction-detection" procedure, thereby calculating the optimal addition amount and giving the process good adaptability. Finally, this requirement strengthens the integration and internal logical rigor of the process, ensuring that the two core links of "calculation" and "production" are no longer isolated steps, but are tightly coupled into an organic whole through unified process parameters. This avoids disconnect between technical solutions and enhances the clarity and stability of the patent protection scope.

[0028] Preferably, the solvent removal process in step four specifically includes two consecutive stages: In the first stage, under the conditions of system absolute pressure of 0.05~0.08 MPa and temperature of 55~65℃, more than 90% of No. 6 extraction solvent oil and some ethanol are removed from the supernatant. In the second stage, when the ethanol content in the distillate exceeds 80% of the total solvent mass, a protection stage is entered. The absolute pressure of the system is reduced to 0.01~0.03 MPa, the temperature is reduced to 40~50℃, and water vapor or inert gas is continuously introduced into the system at a flow rate of 0.1~1.0 L / min until the total residual solvent is less than 10 mg / kg, thus obtaining the high resveratrol peanut oil.

[0029] This desolventizing process adopts a phased strategy of "strong first, then gentle, dynamic response" based on the differences in physical properties of different solvents and the dynamic changes in the system composition during the desolventizing process. In the first stage, utilizing the boiling point difference between No. 6 extraction solvent oil and ethanol, under relatively high system absolute pressure (0.05~0.08 MPa) and appropriate temperature (55~65℃), most of the low-boiling-point No. 6 extraction solvent oil and a portion of ethanol are preferentially, rapidly, and efficiently evaporated. At this stage, the total amount of solvent in the system is large, and the concentration of resveratrol is relatively low. Using strong conditions, most of the desolventizing task can be completed in a short time, improving efficiency. Its key innovation lies in the setting of the switching conditions in the second stage: using "the ethanol content in the distillate accounting for more than 80% of the total solvent mass" as the intelligent criterion for process conversion. This signal indicates that the volatile No. 6 extraction solvent oil in the system has been basically removed, and the residue is mainly ethanol and heat-sensitive resveratrol, with a relatively increased heat intensity on the material. At this point, the conditions are immediately switched to a milder protective phase: the system absolute pressure is reduced to 0.01~0.03 MPa to decrease the driving force of ethanol evaporation, while the temperature is lowered (40~50℃) to directly reduce the heat load. A trace amount of water vapor or inert gas is introduced to reduce solvent partial pressure, provide an inert atmosphere, and potentially form an azeotropic reaction to promote the removal of residual ethanol. This series of adjustments constitutes a closed-loop control system responding to changes in the system's state, aiming to remove the last remaining, difficult-to-remove solvent while minimizing the risk of resveratrol being exposed to high temperature and high vacuum conditions.

[0030] This method resolves the conflict between efficiency and active ingredient protection during the desolventizing process. By automatically switching to milder conditions in the later stages, it significantly reduces the risk of resveratrol oxidation, degradation, or isomerization due to continuous heating, ensuring the content and stability of active ingredients in the final product. Secondly, the entire desolventizing process is more intelligent and efficient. The strong conditions in the early stages guarantee the desolventizing speed, while the precise switching based on component detection in the later stages avoids over-processing or wasted time, optimizing overall energy consumption. Finally, through the synergistic effect of the two stages and the final introduction of protective gas, it ensures that the total residual solvent in the finished oil remains consistently below the stringent safety standard of 10 mg / kg. Simultaneously, the process exhibits high reliability and reproducibility, providing crucial technical support for the continuous and standardized production of high-quality functional oils.

[0031] Preferably, the peanut root powder in step one is obtained through the following steps: Take fresh peanut roots, remove impurities and diseased parts, spray and wash with an aqueous solution containing 0.05-0.15% w / v vitamin C, and then drain. Place the drained peanut roots in a circulating hot air at 40-50℃ for 40-70 minutes to rapidly dehydrate them, reducing their moisture content to 25-35%. Then, under a nitrogen protective atmosphere, slowly dry them at 55-65℃ until the final moisture content is less than 8%. Crush the dried peanut roots to 200-300 mesh to obtain the peanut root powder.

[0032] The design of this peanut root powder preparation method follows a systematic raw material pretreatment logic that combines "source antioxidant protection, gentle gradient dehydration, and extreme physical cell wall disruption." During the washing stage, an aqueous solution containing a low concentration of vitamin C (0.05~0.15%) is sprayed on the material. The principle is to utilize the reducing properties of vitamin C to effectively inhibit polyphenol oxidase activity and simultaneously form a preliminary antioxidant protective layer on the material surface, reducing the oxidative loss of phenolic substances such as resveratrol from the very beginning. The subsequent drying process employs a two-stage strategy: the first stage (40-50℃ hot air, 40-70 min) aims to gently and rapidly reduce the moisture content of the high-moisture fresh raw materials from their initial state to 25-35%. The main purpose of this stage is to significantly reduce the energy consumption and time of subsequent drying by removing most of the free water, while simultaneously inhibiting microbial activity. The second stage involves slow drying at a lower temperature (55-65℃) under an inert nitrogen protective atmosphere until the moisture content is below 8%. The principle behind this is to create an oxygen-deficient and temperature-controlled environment, fundamentally avoiding thermal oxidation and Maillard reactions that may be triggered by high temperatures and aerobic conditions, and maximizing the preservation of the chemical integrity of the heat-sensitive active ingredients. The final pulverization stage requires grinding to 200-300 mesh (i.e., an extremely fine powder state). The core principle is to completely break down the physical barrier of plant cell walls by creating a huge specific surface area and an extremely high cell wall disruption rate, thus creating the optimal mass transfer and reaction interface for subsequent ultrasonic, microwave treatment, and solvent extraction, allowing the active ingredients to be released efficiently and fully.

[0033] This method maximizes the preservation of resveratrol's original content from the source of raw material processing. Through antioxidant cleaning and inert drying, it significantly reduces oxidative degradation losses during pretreatment, laying the material foundation for the high activity content of the final product. Secondly, the staged drying strategy ensures both drying effectiveness and efficiency and safety, avoiding the "burnt outside, raw inside" or component damage problems easily caused by traditional high-temperature single-stage drying. The resulting dry material has a uniform texture, making it easier to pulverize. Most importantly, the final ultrafine powder (200-300 mesh) has excellent physical properties. Its extremely high cell breakage rate significantly improves the efficiency of subsequent physical field treatments (ultrasound, microwave) and solvent extraction aimed at releasing components, essentially "empowering" the entire subsequent process chain. This directly increases the resveratrol dissolution rate per unit of raw material and may shorten the extraction time. This series of interconnected steps ensures that the prepared peanut root powder is a high-quality, highly active, and highly reactive standardized raw material, which is an important prerequisite for the stable and efficient operation of the entire high-resveratrol peanut oil preparation process.

[0034] This invention offers at least the following beneficial effects: The method for preparing high-resveratrol peanut oil described in this invention achieves significant comprehensive benefits through a series of synergistic effects. Firstly, this method creatively realizes the high-value comprehensive utilization of peanut processing by-products. It organically combines peanut meal containing residual oil as a lipid carrier for functional components with specially activated peanut root powder, constructing a "carrier-active substance" synergistic extraction system, significantly improving resource utilization efficiency and product added value. In the raw material pretreatment stage, differentiated and refined physical field treatments are applied to peanuts and peanut root powder, particularly staged, real-time temperature-controlled ultrasonic and microwave combined treatments. This not only promotes cell structure rupture and increases the release rate but also reduces the degradation risk of the heat-sensitive component resveratrol. A balance is achieved between extraction efficiency and activity protection. Its core innovation lies in establishing a precise mathematical model based on dissolution equilibrium and material balance. By measuring the solubility saturation value, simulating the extraction dissolution concentration, and combining it with the residual oil content in the cake, it achieves quantitative and scientific calculation of the proportion of active ingredients added. This fundamentally ensures that the resveratrol content in the finished oil can accurately and stably reach the preset target, overcoming the batch fluctuation problem caused by traditional experience-based addition. In the enrichment and separation stage, the parallel design of series extraction units and solvent preheating achieves efficient and continuous polar gradient extraction, eliminating the temperature lag and waiting time in traditional processes. At the same time, the two-stage dynamic control strategy for solvent removal based on real-time analysis of distillate components ensures safe residue removal while providing targeted protection for the later heat-sensitive stage, effectively preventing the destruction of active ingredients. In addition, the antioxidant cleaning, segmented drying under inert atmosphere protection, and ultra-fine pulverization of peanut roots from the source provide a standardized raw material basis with high quality and high cell damage rate for the entire process. Ultimately, the systematic integration of these technological elements enables the entire process to stably and efficiently produce functional peanut oil products with high resveratrol content, clarity, good stability, and food safety, achieving a leap from low-cost raw materials to high-value-added products.

[0035] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Detailed Implementation

[0036] The present invention will now be described in further detail with reference to specific embodiments, so that those skilled in the art can implement it based on the description.

[0037] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0038] It should be noted that, unless otherwise specified, the experimental methods described in the following implementation plan are all conventional methods, and the reagents and materials described are all commercially available unless otherwise specified.

[0039] In the description of this invention, the terms "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the shown orientation or positional relationship, and are only for the convenience of describing this invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0040] Definition, calibration, and determination method of the process transfer coefficient η The process transfer coefficient η is the core calibration parameter for achieving precise quantitative control in this method. Its physical essence is the ratio of the measured concentration (Cr) of resveratrol in the final finished oil to the preset target concentration (Co) after large-scale production, i.e., η = Cr / Co. It comprehensively reflects the overall efficiency reduction caused by differences in extraction kinetics, separation losses, thermosensitive degradation during desolventizing, and detection errors throughout the entire process from laboratory-scale prediction to large-scale production.

[0041] 1. Definition and Core Calculation Formulas Based on the above-mentioned essence, the definition of η is: η = Cr / Co; In the formula: Cr is the measured concentration of resveratrol (mg / kg) in the final finished oil after large-scale production.

[0042] Co is the target resveratrol concentration (mg / kg) preset for this batch of production, and Co = k × S (k is the safety factor, and S is the solubility saturation value).

[0043] In the model used to guide production material input calculations, η needs to be used as a preset input value. This calculation model is based on material balance, and its derivation process is as follows: a. The total mass of resveratrol required to be supplied by peanut root powder and ultimately dissolved in the residual oil (mass Mo) is: Co × Mo.

[0044] b. According to the laboratory's "pre-set extraction process", the mass of resveratrol that can be dissolved per gram of peanut root powder is: (Ce×Vs) / Ws.

[0045] c. Considering the overall efficiency loss (i.e., η) from laboratory dissolution to the final product, the actual amount of resveratrol that each gram of root powder can contribute to the finished oil is: η×(Ce×Vs) / Ws.

[0046] d. Therefore, the formula for calculating the required peanut root powder mass W is: .

[0047] 2. Method for determining (calibrating) the value of η The preset value of η must be determined through prior calibration experiments, mainly through the following methods: Based on statistical determination of historical production data After the process is stabilized, collect data from multiple consecutive production batches (recommended ≥5 batches). For each batch, record the preset target Co and the measured result Cr, and calculate the single batch η value according to the following formula: η=Cr / Co.

[0048] Take the average value of η for all batches as the preset value for subsequent production.

[0049] 3. Application and Iterative Optimization In actual production, the preset η value obtained from calibration can be substituted into the material feeding calculation formula to achieve accurate material feeding. Simultaneously, the result (Cr) of each batch of formal production serves as a verification of the η value. It is recommended to establish a continuous monitoring mechanism. When the measured Cr / Co ratio (i.e., actual η) of multiple consecutive batches deviates continuously from the preset η value, the calibration procedure should be restarted to update the preset η value, ensuring the long-term accuracy of the model.

[0050] 4. Typical range of values ​​and their significance Under the optimized process conditions described in this invention, the value of η can typically be stabilized between 0.85 and 0.98. The high value within this range demonstrates the efficiency and stability of this process system in achieving "quantitative design." η is a precise bridge connecting "theoretical design (Co)" and "production practice (Cr)," and is key to distinguishing this method from traditional empirical methods in achieving stable and controllable product content.

[0051] Calibration Example: For a pilot-scale batch, the target Co was set at 89.8 mg / kg. Based on a small-scale test result of Ce = 0.40 mg / mL and a temporary preset η' = 0.90, W was calculated. After completing the pilot-scale production, the measured Cr in the finished oil was 85.3 mg / kg. Therefore, the η value for this calibration batch is: η = Cr / Co = 85.3 / 89.8 ≈ 0.95. This value can be used as the preset η for subsequent production.

[0052] Example 1 A method for preparing high-resveratrol peanut oil includes the following steps: Step 1: Peanut pretreatment: 10 kg of peanuts in their shells were shelled to obtain peanut kernels. The kernels were spread evenly on a microwave-safe tray, with the layer thickness strictly controlled to 2 cm. The tray was placed in a microwave oven with a power setting of 2 kW. Intermittent, segmented processing was used: each processing session lasted 3 minutes, followed by a 1-minute pause; this cycle was repeated for a total microwave processing time of 10 minutes. After processing, the peanuts were allowed to cool naturally to room temperature. They were then pressed using a screw press to separate crude oil and peanut meal. The residual oil content of this batch of peanut meal was determined to be 8%.

[0053] Step 2: Preparation and activation treatment of peanut root powder: Raw material processing: Take 5 kg of fresh peanut roots and remove impurities. Wash with a 0.05% w / v vitamin C aqueous solution and drain. Place the drained peanut roots in a 40℃ circulating hot air chamber for rapid dehydration for 40 min, reducing the moisture content to approximately 35%. Then transfer to a nitrogen-filled drying oven and slowly dry at 55℃ until the final moisture content is below 8%. Ultrafinely pulverize the dried peanut roots and pass them through a 200-mesh sieve to obtain peanut root powder.

[0054] Segmented ultrasonic treatment: Weigh an appropriate amount of peanut root powder and mix it with deionized water at a material-to-liquid ratio of 1:10 to obtain a slurry, which is then transferred to an ultrasonic treatment container (the slurry temperature is approximately 25℃ at this point). Start the ultrasonic treatment: The first stage involves continuous treatment at 200 W for 5 minutes; the second stage involves treatment at 300 W with an intermittent mode of "30 seconds on, 15 seconds off" for 5 minutes; the third stage involves continuous treatment at 150 W for 3 minutes. Monitor the temperature in real time during the treatment process. When the material temperature exceeds 65℃, pause the ultrasonic treatment and start air cooling, resuming treatment once the temperature drops below 55℃.

[0055] Microwave treatment: The ultrasonically treated slurry undergoes solid-liquid separation, and the resulting wet material is spread evenly on a microwave-safe tray with a layer thickness of 1 cm. The microwave equipment equipped with infrared thermometry is started, with an initial power of 2 kW and a target temperature of 55-60℃. When the infrared sensor (monitoring interval 10 seconds) shows a temperature below 55℃, the equipment operates continuously at 3 kW; when the temperature rises to 55-60℃, it switches to a 2 kW pulse mode (on for 30 seconds, off for 30 seconds); if the temperature exceeds 60℃, heating is immediately stopped and air cooling is initiated, resuming according to the established rules once the temperature drops below 55℃. The total processing time is controlled within 8 minutes. After processing, the material is dried at 55℃ until the moisture content is below 8%, yielding activated peanut root powder.

[0056] Step 3: Precise Calculation and Mixing Determine key parameters: The solubility saturation value S of resveratrol in the crude oil pressed in this study was determined to be 350.0 mg / kg.

[0057] The target resveratrol content in the finished oil is set as Co = k × S, where k is taken as 0.5. The calculated Co is 175.0 mg / kg (Co <S)。

[0058] Accurately weigh 0.1 kg of the activated peanut root powder sample (Ws) and place it in the experimental apparatus. A laboratory-simulated extraction process, identical to that used in subsequent step four (production extraction), was performed to determine the Ce value. Specifically, the simulated extraction followed the parameters described in step four of this embodiment: using the same ratio of the first extraction solvent (extraction solvent oil No. 6:ethanol = 1:2, v / v), at the same temperature of 30°C, using a small laboratory circulating apparatus to simulate the same mixed extraction process, and for the same extraction time of 25 minutes. After extraction, solid-liquid separation was performed to obtain the extract. The concentration of resveratrol in the extract, Ce = 0.35 mg / mL, was determined using high-performance liquid chromatography.

[0059] The total mass of peanut cake obtained from this pressing is Mc = 0.6 kg. Based on its residual oil rate R = 8.0%, the residual oil content Mo is calculated to be Mo = Mc × 8.0% = 0.048 kg.

[0060] Based on historical production data, the process transfer coefficient η for this batch of resveratrol is pre-set to be 0.95.

[0061] Calculate the required root powder mass: Through formula Calculate the required mass W of peanut root powder.

[0062] Substitute the parameter values: Co=175.0 mg / kg; Mo=0.048 kg; Ws=0.1kg; eta=0.95; Ce=0.35mg / mL; Vs=50 mL; The result was W≈50.53 g.

[0063] Determine the mixing ratio and mix: Calculate the addition ratio of peanut root powder in the mixed raw materials P=W / (W+Mc)≈7.77%.

[0064] Based on this calculation, weigh approximately 50.53 g of peanut root powder and 600 g of peanut meal and mix them evenly to obtain the mixed raw materials.

[0065] Step 4: Gradient Extraction All the mixed raw materials are loaded into the extraction tank of the first extraction unit. The first extraction solvent (extraction solvent No. 6: ethanol = 1:2) is injected into the first extraction tank, and the second extraction solvent (extraction solvent No. 6: ethanol = 1:3) is injected into the second extraction tank at the same time.

[0066] Start the circulation pump and heat exchanger of the first extraction unit, control the extraction temperature at 30°C, and the circulation flow rate at 4 times the tank volume per hour. At the same time, start the circulation pump and heat exchanger of the second extraction unit to independently circulate and preheat the second extraction solvent to 30°C.

[0067] After the first stage of extraction is completed, all the liquid in the first extraction tank is pumped out and collected as extract A. Then, all the preheated second extraction solvent in the second extraction tank is pumped into the first extraction tank and mixed with the raw materials. The circulation pump is restarted, and the second stage of extraction is carried out at the same temperature and flow rate. The second stage of extraction lasts for the same time (approximately 25 minutes). After completion, all the liquid in the tank is pumped out and collected as extract B.

[0068] Combine extracts A and B to obtain the total extract mixture.

[0069] Step 5, Two-stage solvent removal: The extraction mixture is separated into solid and liquid components, and the supernatant is used for solvent removal.

[0070] First stage: Solvent removal is carried out under the conditions of system absolute pressure of 0.08 MPa and temperature of 55℃ until the proportion of ethanol in the distillate increases significantly.

[0071] Second stage: When the ethanol content in the distillate exceeds 80% of the total solvent mass, it automatically switches to the protection stage: the absolute pressure of the system is adjusted to 0.03 MPa, the temperature is reduced to 40℃, and nitrogen is continuously introduced into the system at a flow rate of 0.5 L / min.

[0072] The solvent was continuously removed until the total residual solvent was less than 10 mg / kg as determined by headspace gas chromatography, thus obtaining high resveratrol peanut oil.

[0073] Example 2 A method for preparing high-resveratrol peanut oil, comprising: Step 1: Peanut pretreatment: Take 1.0 kg of peanut kernels and spread them evenly on a microwave-safe tray to a thickness of 3 cm. Place the tray in a microwave oven, set the microwave power to 3 kW, and use an intermittent mode of "processing for 4 min, then pausing for 1.5 min," for a total microwave processing time of 15 min. After processing, allow the mixture to cool naturally to room temperature and then press it. The resulting peanut cake weighed 0.58 kg, and its residual oil content was determined to be 10.0%.

[0074] Step 2: Preparation and activation treatment of peanut root powder: Raw material processing: Take 0.100 kg of fresh peanut roots, spray and wash them with an aqueous solution containing 0.1% w / v vitamin C, and drain them. Place them in a 45℃ circulating hot air chamber for 55 min to dehydrate them to a moisture content of about 30%, and then dry them at 60℃ under a CO2 atmosphere until the moisture content is <8%. Grind them into ultrafine powder and pass them through a 250-mesh sieve to obtain peanut root powder.

[0075] Segmented ultrasonic treatment: Weigh the above-mentioned peanut root powder and mix it with deionized water at a material-to-liquid ratio of 1:10 to obtain a slurry, which is then transferred to an ultrasonic treatment container. Start the ultrasonic treatment: First stage: continuous treatment at 300 W for 7.5 min; Second stage: intermittent treatment at 350 W with a "30 s working, 15 s rest" mode for 7.5 min; Third stage: continuous treatment at 225 W for 4 min. Monitor the temperature in real time during treatment. When the material temperature exceeds 65℃, pause the ultrasonic treatment and start air cooling, resuming treatment once the temperature drops below 55℃.

[0076] Microwave treatment: The ultrasonically treated slurry was separated into solid and liquid components. The wet material was spread evenly on a microwave-safe tray with a layer thickness of 2 cm. In a microwave device equipped with infrared thermography, the temperature control logic of Example 1 was followed: initial power 2.5 kW; continuous operation at 3.5 kW when the temperature was below 55°C; switching to a 2.5 kW pulse mode (on for 30 seconds, off for 30 seconds) when the temperature was between 55 and 60°C; stopping heating and air cooling when the temperature exceeded 60°C. The total processing time was controlled within 11 minutes. After processing, the material was dried at 60°C until the moisture content was below 8%, yielding activated peanut root powder.

[0077] Step 3: Precise Calculation and Mixing Determine key parameters: The solubility saturation value S of resveratrol in the crude oil pressed in this study was determined to be 291.1 mg / kg.

[0078] The target resveratrol content in the finished oil is set as Co = k × S, where k is taken as 0.725. The calculated Co is 211.0 mg / kg (Co <S)。

[0079] Weigh 0.1 kg of the activated peanut root powder sample (Ws) and perform simulated extraction using the same solvent and conditions as in step four. The extraction solvent volume was 50 mL. After solid-liquid separation, the resveratrol concentration Ce in the extract was measured to be 0.40 mg / mL.

[0080] The total mass of peanut meal obtained this time Mc=0.580 kg. Based on its residual oil rate R=10.0%, the residual oil content Mo=Mc×10.0% = 0.058 kg.

[0081] Based on historical production data, the process transfer coefficient η for this batch of resveratrol is pre-set to be 0.95.

[0082] Calculate the required root powder mass: Through formula Calculate the required mass W of peanut root powder.

[0083] Substituting the parameter values, we calculate W≈64.41g.

[0084] Determine the mixing ratio and mix: The proportion of peanut root powder added to the mixed raw materials is calculated as P = W / (W+Mc)≈10.0%.

[0085] Based on this calculation, weigh out 64.41g of peanut root powder and 580g of peanut meal and mix them evenly to obtain the mixed raw materials.

[0086] Step 4: Gradient Extraction All the mixed raw materials were loaded into the extraction tank of the first extraction unit. Solvent preparation: The first extraction solvent was prepared by mixing No. 6 extraction solvent oil and ethanol at a volume ratio of 1:2.5; the second extraction solvent was prepared by mixing No. 6 extraction solvent oil and ethanol at a volume ratio of 1:3.5.

[0087] Start the circulation pump and heat exchanger of the first extraction unit, control the extraction temperature at 40°C, the circulation flow rate at 5.5 times the tank volume / hour, and circulate for 25 minutes. Simultaneously, start the circulation pump and heat exchanger of the second extraction unit to independently circulate and preheat the second extraction solvent to 40°C.

[0088] After the first stage of extraction is completed, all the liquid in the first extraction tank is pumped out and collected as extract A. Then, all the preheated second extraction solvent in the second extraction tank is pumped into the first extraction tank and mixed with the raw materials. The circulation pump is restarted, and the second stage of extraction is carried out for 28 minutes at the same temperature and flow rate.

[0089] Combine extracts A and B to obtain the total extract mixture.

[0090] Step 5, Two-stage solvent removal: The extraction mixture is separated into solid and liquid components, and the supernatant is used for solvent removal.

[0091] First stage: Remove most of the solvent under the conditions of system absolute pressure of 0.065 MPa and temperature of 60℃.

[0092] Second stage: When the ethanol content in the distillate exceeds 80% of the total solvent mass, the system automatically switches to the protection stage: the absolute pressure of the system is adjusted to 0.02 MPa, the temperature is reduced to 45℃, and water vapor is continuously introduced into the system at a flow rate of 0.3 L / min.

[0093] The solvent was continuously removed until the total residual solvent was less than 10 mg / kg, yielding high resveratrol peanut oil with a mass of approximately 65.3 g (calculated based on residual oil from the oil cake).

[0094] Example 3 A method for preparing high-resveratrol peanut oil, comprising: Step 1: Peanut pretreatment: Take 1.0 kg of peanut kernels and spread them evenly on a microwave-safe tray to a thickness of 4 cm. Place the tray in a microwave oven, set the microwave power to 4 kW, and use an intermittent mode of "processing for 5 minutes, then pausing for 2 minutes" for a total microwave processing time of 20 minutes. After processing, allow the mixture to cool naturally to room temperature and then press it. The resulting peanut cake weighed 0.56 kg, and its residual oil content was determined to be 12.0%.

[0095] Step 2: Preparation and activation treatment of peanut root powder: Raw material processing: Take 0.100 kg of fresh peanut roots, spray and wash them with an aqueous solution containing 0.15% w / v vitamin C, and drain them. Place them in a 50℃ circulating hot air chamber for 70 min to dehydrate them to a moisture content of about 25%, and then dry them at 65℃ under nitrogen protection until the moisture content is <8%. After pulverizing, pass them through a 300-mesh sieve to obtain peanut root powder.

[0096] Segmented ultrasonic treatment: Weigh the above-mentioned peanut root powder and mix it with deionized water at a material-to-liquid ratio of 1:10 to obtain a slurry, which is then transferred to an ultrasonic treatment container. Start the ultrasonic treatment: First stage: continuous treatment at 400 W for 10 min; Second stage: intermittent treatment at 400 W with a "30 s working, 15 s rest" mode for 10 min; Third stage: continuous treatment at 300 W for 5 min. Monitor the temperature in real time during the treatment. When the material temperature exceeds 65℃, pause the ultrasonic treatment and start air cooling, resuming treatment once the temperature drops below 55℃.

[0097] Microwave treatment: The ultrasonically treated slurry was separated into solid and liquid components. The wet material was spread evenly on a microwave-safe tray with a layer thickness of 3 cm. In a microwave device equipped with infrared thermography, the temperature control logic of Example 1 was followed: initial power 3.0 kW; continuous operation at 4.0 kW when the temperature was below 55°C; switching to a 3.0 kW pulse mode (on for 30 seconds, off for 30 seconds) when the temperature was between 55 and 60°C; stopping heating and air cooling when the temperature exceeded 60°C. The total processing time was controlled within 15 minutes. After processing, the material was dried at 65°C until the moisture content was below 8%, yielding activated peanut root powder.

[0098] Step 3: Precise Calculation and Mixing Determine key parameters: The solubility saturation value (S) of resveratrol in the crude oil pressed in this study was determined to be 92.6 mg / kg.

[0099] The target resveratrol content in the finished oil is set as Co = k × S, where k is taken as 0.95. The calculated Co is 88.0 mg / kg (Co <S)。

[0100] Weigh 1 kg of the activated peanut root powder sample (Ws) and perform a simulated extraction using the same solvent and conditions as in step four. The extraction solvent volume was 50.0 mL. After solid-liquid separation, the resveratrol concentration Ce in the extract was measured to be 2.0 mg / mL.

[0101] The total mass of peanut meal obtained this time is Mc=0.560 kg. Based on its residual oil rate R=12.0%, the residual oil content Mo=Mc×12.0% = 0.0672 kg.

[0102] Based on historical production data, the process transfer coefficient η for this batch of resveratrol is pre-set to be 0.95.

[0103] Calculate the required root powder mass: Through formula Calculate the required mass W of peanut root powder.

[0104] Substituting the parameter values, we calculate W≈62.25 g.

[0105] Determine the mixing ratio and mix: The proportion of peanut root powder added to the mixed raw materials is calculated as P = W / (W+Mc)≈10.0%.

[0106] Based on this calculation, weigh 62.25 g of activated peanut root powder and 560 g of peanut meal and mix them evenly to obtain the mixed raw materials.

[0107] Step 4: Gradient Extraction All the mixed raw materials were loaded into the extraction tank of the first extraction unit. Solvent preparation: The first extraction solvent was prepared by mixing No. 6 extraction solvent oil and ethanol at a volume ratio of 1:3; the second extraction solvent was prepared by mixing No. 6 extraction solvent oil and ethanol at a volume ratio of 1:4.

[0108] Start the circulation pump and heat exchanger of the first extraction unit, control the extraction temperature at 50°C, the circulation flow rate at 7.0 times the tank volume / hour, and circulate for 28 minutes. Simultaneously, start the circulation pump and heat exchanger of the second extraction unit to independently circulate and preheat the second extraction solvent to 50°C.

[0109] After the first stage of extraction is completed, all the liquid in the first extraction tank is pumped out and collected as extract A. Then, all the preheated second extraction solvent in the second extraction tank is pumped into the first extraction tank and mixed with the raw materials. The circulation pump is restarted, and the second stage of extraction is carried out for 32 minutes at the same temperature and flow rate.

[0110] Combine extracts A and B to obtain the total extract mixture.

[0111] Step 5, Two-stage solvent removal: The extraction mixture is separated into solid and liquid components, and the supernatant is used for solvent removal.

[0112] First stage: Remove most of the solvent under the conditions of system absolute pressure of 0.05 MPa and temperature of 65℃.

[0113] Second stage: When the ethanol content in the distillate exceeds 80% of the total solvent mass, the system automatically switches to the protection stage: the absolute pressure of the system is adjusted to 0.01 MPa, the temperature is reduced to 50℃, and nitrogen is continuously introduced into the system at a flow rate of 0.8 L / min.

[0114] The solvent was continuously removed until the total residual solvent was less than 10 mg / kg, yielding high resveratrol peanut oil with a mass of approximately 78.5 g (calculated based on residual oil from the oil cake).

[0115] Comparative Example 1 A method for preparing peanut oil, wherein steps one and two are the same as in Example 2.

[0116] Addition ratio determination: Solubility saturation value determination and preset extraction process were not performed. Based on previous immature experience, the addition ratio of peanut root powder was fixed at 10% of the peanut meal mass. 6.0 kg of peanut meal was weighed, and 0.60 kg of activated peanut root powder was added accordingly, and the mixture was mixed to obtain the mixed raw material.

[0117] Extraction operation: The operation is carried out using a single extraction tank.

[0118] All the mixed raw materials were loaded into the extraction tank and the first extraction solvent (extraction solvent No. 6: ethanol = 1:2) was added. The amount of solvent used was the same as in Example 2.

[0119] Start the circulation pump and extract at 30°C for a fixed time of 25 minutes (this time is an empirical value).

[0120] After extraction, all the extract was pumped out and collected (extract A).

[0121] Then, a second extraction solvent (extraction solvent No. 6: ethanol = 1:3) at room temperature (approximately 25°C) is injected into the solid material in the same extraction tank for a second extraction. Due to the low solvent temperature, the system needs to be reheated to 30°C, a process that takes approximately 8 minutes. Extraction is then repeated for a fixed period of 25 minutes.

[0122] After extraction, the second extract (extract B) is pumped out and combined with extract A.

[0123] Subsequent solid-liquid separation and solvent removal were carried out in step five of Example 2. Solvent removal was performed under single-stage conditions (system absolute pressure 0.08 MPa, 60°C) until the residue met the standard.

[0124] Comparative Example 2 A method for preparing peanut oil, comprising peanut pretreatment: peanuts are not microwaved, but the peanut kernels are directly pressed to obtain crude oil and peanut meal with low residual oil content (about 6%) and insufficient cell structure destruction.

[0125] Peanut root powder preparation and processing: Simplified pretreatment: Fresh peanut roots are simply washed with water, drained, and then dried in hot air at 60℃ in one go until the moisture content is <8%. After coarsely grinding to 20 mesh, it is used as "peanut root powder".

[0126] Simplified physical treatment: Only a single-segment ultrasonic treatment (400 W power, continuous treatment for 15 min) is performed, without temperature monitoring or active cooling. After treatment, the product is directly dried without subsequent microwave treatment.

[0127] Subsequent steps, such as calculating the addition ratio (based on a pre-set extraction process using simplified root powder, with a lower expected Ce value), mixing, extraction, and desolventizing (under single conditions), were all performed using the traditional method described in Comparative Example 1.

[0128] The peanut oil products obtained in Examples 1-3 and Comparative Examples 1-2 were used as samples for the following tests: Resveratrol content detection: Take 1.00g of each sample, extract with 80% ethanol solution, dilute to volume, filter through a 0.22μm filter membrane, and perform gradient elution on a C18 column using 0.1% formic acid aqueous solution and methanol as the mobile phase. Detect the resveratrol content at a wavelength of 306nm. At the same time, store the product at 4℃ for 30 days, observe the appearance changes regularly, and detect solvent residues using headspace gas chromatography.

[0129] Product stability test: Each sample was dispensed into a transparent glass bottle and stored in a refrigerator at 4°C for 30 days. The condition of the samples was observed and recorded on days 0, 7, 15, and 30, including whether turbidity or precipitation occurred.

[0130] Solvent residue detection: Headspace gas chromatography was used. Chromatographic conditions: DB-624 column (30 m × 0.32 mm × 1.8 μm), injection port temperature 200℃, detector temperature 250℃, column temperature program: 40℃ for 5 min, then ramped up to 150℃ at 10℃ / min and held for 2 min. 2.0 g of sample was accurately weighed for detection.

[0131] Statistical methods: All data are expressed as mean ± standard deviation. One-way ANOVA was performed using SPSS 22.0 software. A p-value < 0.05 was considered statistically significant. The test results are shown in Tables 1 and 2.

[0132] Table 1. Resveratrol content and stability results for each sample Table 2 Changes in the state of each product during storage (4℃) The experimental data above (Tables 1 and 2) clearly demonstrate the significant advantages of the method described in this invention (Examples 1-3) in preparing high-resveratrol peanut oil. It not only achieves efficient and stable enrichment of the target component but also ensures the product's excellent physical stability and safety. The failures of the two comparative products, on the other hand, conversely confirm the necessity and synergy of the various technical aspects of this invention.

[0133] 1. Example Product: Mechanism for Achieving High Content and High Stability The resveratrol content of the products in Examples 1-3 all accurately reached or approached their preset target values ​​(168.3, 200.5, and 83.6 mg / kg, respectively), and remained clear and transparent throughout storage. This is attributed to the systematic technical solution of the present invention. Precise quantitative feeding ensures the target content: the core lies in the precise calculation model established by this invention. This model uses the solubility saturation value (S) as the theoretical upper limit, the actual dissolution concentration (Ce) measured by laboratory simulation extraction to reflect the raw material potential, and the process transfer coefficient (η) to correct for losses in large-scale production. Finally, it calculates the peanut root powder addition amount (W) that precisely matches the residual oil content (Mo) of the cake meal. In the examples, the measured content (Cr) highly matches the preset target (Co) (Cr / Co≈η), verifying the reliability and accuracy of the model from "design" to "output," fundamentally solving the batch fluctuation problem.

[0134] A sophisticated pretreatment and enrichment process ensures high extraction efficiency: In this example, peanut root powder undergoes a series of ultrasonic-microwave synergistic treatments, including antioxidant cleaning, inert drying, ultrafine pulverization, and segmented temperature control. This series of operations maximizes the preservation of resveratrol activity and achieves extremely high cell wall disruption rates, creating optimal conditions for subsequent extraction. Subsequently, a tandem extraction system with increasing polarity is employed to achieve gentle, efficient, and continuous enrichment of the target components.

[0135] A dynamically controllable desolventizing process ensures component activity and product purity: The two-stage desolventizing process rapidly removes most of the solvent in the initial stage under high vacuum and temperature, and then intelligently switches to milder conditions (pressure reduction, temperature reduction, and introduction of protective gas) based on the distillate composition in the later stage. This strategy effectively removes solvent (residual <10 mg / kg) while greatly avoiding the degradation of resveratrol in the later stage under relatively concentrated and heated conditions. This is the key to maintaining product stability and clarity while achieving high content.

[0136] 2. Analysis of the reasons for failure of comparative products Comparative Example 1 (empirical fixed-ratio addition): Its resveratrol content (approximately 52.7 mg / kg) was significantly lower than that of Example 2 (200.5 mg / kg), which used the same addition ratio but was based on precise calculations, and the product was turbid. The fundamental reason is that it abandoned the quantitative calculation model of this invention and used a fixed high proportion (10%) of root powder. This resulted in the total amount of resveratrol in the extract potentially far exceeding the actual dissolving capacity of the batch of residual oil (i.e., exceeding its solubility saturation value). During subsequent desolvation and storage, excess resveratrol precipitated from the oil phase, forming microcrystalline crystals or turbidity, resulting in a turbid product and a low measured content. This precisely proves that empirical addition that deviates from the dissolving capacity of the carrier oil and the actual dissolution rate of the raw material is unreliable.

[0137] Comparative Example 2 (Simplified Raw Material Pretreatment): The product contained extremely low resveratrol content (approximately 2.3 mg / kg) and produced severe precipitation. The reason lies in the serious defects in its pretreatment process: (1) No antioxidant was used during washing, and the drying process was carried out under aerobic and relatively high temperature conditions, resulting in significant oxidative loss of resveratrol in the early stage of pretreatment; (2) Only coarsely pulverized to 20 mesh, the cell wall breakage rate was extremely low, and a single, strong ultrasonic treatment was used, which may have led to the degradation of the remaining active ingredients due to local overheating; (3) No subsequent microwave-assisted extraction was performed. As a result, the already limited amount of resveratrol in the raw material could not be effectively released into the solvent, resulting in low final extraction efficiency. The low-content product may contain both incompletely extracted plant fine particles and oxidized polymerized products, which together lead to precipitation. This highlights the indispensability of the full-process pretreatment scheme of this invention, from source antioxidant protection and deep physical cell wall breakage to gentle gradient extraction, for obtaining high-activity, high-yield raw materials.

[0138] Furthermore, by employing the calculation model Co = k×S, the concentration of resveratrol in the finished oil was ensured to remain below its immediate solubility saturation value, with sufficient safety margin reserved to cope with changes in storage conditions such as temperature fluctuations. Accelerated stability tests (e.g., storage at 40℃ for 30 days) showed that the products prepared by the method of this invention remained clear and transparent, with no resveratrol crystal precipitation, while the product of Comparative Example 1, which did not use this model, showed significant turbidity. This demonstrates the crucial role of the quantitative calculation model in ensuring the long-term physical stability of the product. Simultaneously, the intelligent switching based on the ethanol ratio during the desolventizing stage effectively reduced the exposure time under higher temperatures and system absolute pressures in the later stages. Measurements showed that the cis-trans isomer ratio of resveratrol in the product remained stable, further verifying the effectiveness of this dynamic protection strategy in maintaining the chemical stability of the active ingredient.

[0139] Conclusion: This invention systematically solves the three major technical bottlenecks pointed out in the background art through an integrated process of "differentiated and precise pretreatment → quantitative calculation model-guided feeding → efficient gradient enrichment → intelligent desolventizing protection." The stark contrast between the examples and comparative examples not only confirms the technical effectiveness of this method but also profoundly reveals the specific roles and necessity of each technical feature in solving specific technical problems and ultimately achieving the goals of high product content and high stability.

[0140] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and embodiments shown and described herein.

Claims

1. A method for preparing high-resveratrol peanut oil, characterized in that, Includes the following steps: Step 1: Take peanut root powder and subject it to segmented ultrasonic treatment and microwave treatment in sequence. The segmented ultrasonic treatment includes at least two stages with different power or modes, and the material temperature is controlled during the treatment. Take peanuts and microwave them, then press them to obtain crude oil and peanut cake containing 8-12% residual oil. Step 2: Determine the solubility saturation value S of resveratrol in the pressed crude oil, and set the resveratrol content Co of the target finished oil, where Co = k × S, and k is a coefficient of 0.5~0.95; Based on Co and S, determine the addition ratio of peanut root powder in the mixed raw materials in the following way: Measure the resveratrol dissolution concentration Ce of the peanut root powder treated in Step 1 under the preset extraction process, and calculate it in combination with the residual oil mass Mo of the peanut cake; then mix the peanut cake and the peanut root powder treated in Step 1 according to the calculated addition ratio to obtain the mixed raw materials; Step 3: Use a series extraction system to extract the mixed raw materials. The extraction operation includes at least two stages, and the polarity of the extraction solvent used in the subsequent stages is higher than that in the previous stage. Step 4: Perform solid-liquid separation on the extracted mixture to obtain supernatant, and perform solvent removal treatment on the supernatant. The solvent removal treatment includes: a first stage of removing most of the solvent under vacuum conditions; In the second stage, when the ethanol content in the distillate exceeds 80% of the total solvent mass, the process switches to a protection stage with higher vacuum and lower temperature to continue desolventizing until the solvent residue meets the standard, thus obtaining the high resveratrol peanut oil.

2. The method for preparing high-resveratrol peanut oil as described in claim 1, characterized in that, The microwave treatment process for peanuts in step one is as follows: The peanuts are spread evenly on a microwave-safe tray with a layer thickness of 2-4 cm and placed in a microwave device for processing at a microwave power of 2-4 kW. The microwave processing is carried out intermittently in segments, specifically: after each continuous processing for 3-5 minutes, there is a 1-2 minute pause, with a total microwave processing time of 10-20 minutes. After the microwave processing is completed, the peanuts are allowed to cool naturally to room temperature.

3. The method for preparing high-resveratrol peanut oil as described in claim 1, characterized in that, The segmented ultrasonic treatment process of peanut root powder in step one is as follows: The first stage involves continuous treatment with an ultrasonic power of 200-400 W for 5-10 minutes. The second stage uses an ultrasonic power of 300-400 W and is treated in an intermittent mode for 5-10 minutes. The working cycle of the intermittent mode is 30 seconds of ultrasonic treatment followed by a 15-second interval. The third stage involves continuous treatment with ultrasonic power of 150~300 W for 3~5 minutes; During the segmented ultrasonic treatment process, the material temperature is monitored in real time. When the material temperature exceeds 65°C, the ultrasonic treatment is paused and air cooling is started. The ultrasonic treatment is resumed when the material temperature drops below 55°C.

4. The method for preparing high-resveratrol peanut oil as described in claim 3, characterized in that, The microwave treatment process of peanut root powder in step one is as follows: The ultrasonically treated peanut root powder is spread evenly on a microwave-specific support tray, with the layer thickness controlled between 1 and 3 cm, and then placed in a microwave device equipped with an infrared temperature sensor. Start microwave processing, with the initial power set to 2~3 kW and the target control temperature range set to 55~60℃; During microwave processing, an infrared temperature sensor monitors the surface temperature of the material in real time at 10-second intervals. When the material temperature is detected to be below 55℃, the microwave equipment operates continuously at a power of 3~4 kW. When the material temperature is detected to rise to between 55 and 60°C, the microwave equipment switches to pulse working mode, with its working power adjusted to 2 to 3 kW and its working cycle being 30 seconds on and 30 seconds off. When the material temperature is detected to exceed 60°C, the microwave equipment immediately stops heating and starts air cooling until the material temperature drops below 55°C, then heating is resumed according to the above rules. The total duration of the microwave processing is controlled within the range of 8 to 15 minutes.

5. The method for preparing high-resveratrol peanut oil as described in claim 1, characterized in that, The proportion of peanut root powder in the mixed raw materials in step two is determined by the following method: The solubility saturation value S of resveratrol in the pressed crude oil was determined; the resveratrol content Co of the target finished high-resveratrol peanut oil was set, where Co = k × S, and k is a coefficient of 0.5 to 0.

95. Weigh the peanut root powder processed in step one as a sample, with a mass of Ws (kg); perform an experimental extraction operation on the sample using a preset extraction process, with an extraction solvent volume of Vs (mL); perform solid-liquid separation on the mixture after experimental extraction to obtain an extract; determine the concentration of resveratrol Ce (mg / mL) in the extract. Obtain the mass Mc (kg) of the peanut meal obtained in step one; and calculate the mass of residual oil Mo = Mc × R based on its residual oil content R, where R ranges from 8% to 12%. Through formula Calculate the required peanut root powder mass W, kg; where η is the resveratrol process transfer coefficient preset based on historical production data, and its value range is 0 < η ≤ 1; Calculate the proportion P of peanut root powder in the mixed raw materials, P=W / (W+Mc).

6. The method for preparing high-resveratrol peanut oil as described in claim 5, characterized in that, The extraction operation in step three is performed through a system consisting of a first extraction unit and a second extraction unit connected in series; each of the first and second extraction units includes an extraction tank, a circulating pump, and a heat exchanger; the specific steps of the extraction operation are as follows. All the mixed raw materials are loaded into the extraction tank of the first extraction unit; a first extraction solvent is injected into the extraction tank of the first extraction unit, the first extraction solvent being prepared by mixing No. 6 extraction solvent oil and ethanol at a volume ratio of 1:2 to 1:3; at the same time, a second extraction solvent is injected into the extraction tank of the second extraction unit, the second extraction solvent being prepared by mixing No. 6 extraction solvent oil and ethanol at a volume ratio of 1:3 to 1:4; Start the circulation pump of the first extraction unit to circulate the material in the first extraction unit between the extraction tank and the heat exchanger, maintain the temperature at 30~50℃, and the circulation flow rate is 4~7 times the effective volume of the extraction tank per hour, and circulate for 20~30 minutes; at the same time, start the circulation pump of the second extraction unit to circulate the second extraction solvent independently between the extraction tank and the heat exchanger of the second extraction unit, and maintain the temperature at 30~50℃ as well. After the first extraction unit completes the cyclic extraction, all the liquid in the extraction tank of the first extraction unit is pumped out and used as the extracted mixture for subsequent processing. Then, the preheated second extraction solvent in the extraction tank of the second extraction unit is pumped into the extraction tank of the first extraction unit, mixed with the mixed raw materials, and the above cyclic extraction steps are repeated for 20-30 minutes. After this extraction is completed, all the liquid in the extraction tank of the first extraction unit is pumped out and combined with the previously pumped liquid to form a mixture for further processing.

7. The method for preparing high-resveratrol peanut oil as described in claim 6, characterized in that, The extraction process preset in step two is the same as the extraction operation described in step three.

8. The method for preparing high-resveratrol peanut oil as described in claim 1, characterized in that, The solvent removal process in step four specifically includes two consecutive stages: In the first stage, under the conditions of system absolute pressure of 0.05~0.08 MPa and temperature of 55~65℃, more than 90% of No. 6 extraction solvent oil and some ethanol are removed from the supernatant. In the second stage, when the ethanol content in the distillate exceeds 80% of the total solvent mass, a protection stage is entered. The absolute pressure of the system is reduced to 0.01~0.03 MPa, the temperature is reduced to 40~50℃, and water vapor or inert gas is continuously introduced into the system at a flow rate of 0.1~1.0 L / min until the total residual solvent is less than 10 mg / kg, thus obtaining the high resveratrol peanut oil.

9. The method for preparing high-resveratrol peanut oil as described in claim 1, characterized in that, The peanut root powder in step one is obtained through the following steps: Take fresh peanut roots, remove impurities and diseased parts, spray and wash with an aqueous solution containing 0.05-0.15% w / v vitamin C, and then drain. Place the drained peanut roots in a circulating hot air at 40-50℃ for 40-70 minutes to rapidly dehydrate them, reducing their moisture content to 25-35%. Then, under a nitrogen protective atmosphere, slowly dry them at 55-65℃ until the final moisture content is less than 8%. Crush the dried peanut roots to 200-300 mesh to obtain the peanut root powder.

Images