Processing method of peanut butter

Abstract

The invention provides a processing method of peanut butter, and belongs to the technical field of food processing. Peanut kernels are degreased through a hydraulic oil pressing device, the content of triglyceride in the peanut kernels is reduced, and product energy is reduced; in order to make up flavor loss caused by reduction of the grease content, enzyme and protease are adopted to conduct enzymolysis on degreased peanut kernels, the hydrolytic activity of protein and saccharides is improved, the content of free amino acid and reducing sugar is increased, and a flavor precursor is provided for Maillard reaction in the subsequent heat treatment process; the heat treatment can promote the generation of aroma substances and enable the flavor to be more harmonious; in order to ensure the quality of the peanut butter and improve the fluidity of the peanut butter, the crushed peanuts after heat treatment and the light-fat peanut oil are mixed and ground, so that the light-fat peanut oil is uniformly dispersed. Compared with traditional peanut triglyceride, the light-fat peanut oil has a lower metabolic energy value and good interfacial activity, not only can improve the rheological property, lubricity and structural stability of the peanut butter, but also can promote release and retention of flavor active substances.

Description

Technical Field

[0001] This invention belongs to the field of food processing technology, and in particular relates to a method for processing peanut butter. Background Technology

[0002] Peanuts are rich in high-quality protein, unsaturated fatty acids, carbohydrates, as well as various vitamins and minerals. They are an important plant-based food ingredient with high nutritional value and a wide range of consumer bases.

[0003] Peanut butter is a typical processed product made primarily from peanuts. Due to its rich flavor, smooth texture, and wide range of applications, it is widely used in baked goods, snack foods, and functional foods. However, most commercially available peanut butter uses full-fat roasted peanuts as its base, resulting in generally high fat and energy content, which does not meet current consumer demand for low-energy, healthier foods. Existing low-fat peanut butter is usually achieved through heavy defatting or reducing the amount of added oil. However, these methods easily damage the original structure and lipid distribution of peanut butter, leading to decreased lubricity, a coarse texture, and insufficient flavor release. It is difficult to maintain the sweet and fragrant flavor and good taste of peanut butter while reducing its energy content. Summary of the Invention

[0004] The purpose of this invention is to provide a peanut butter processing method that produces peanut butter with low energy content while maintaining the sweet and fragrant flavor and good taste of peanut butter.

[0005] This invention provides a method for processing peanut butter, comprising the following steps: Peanut kernels were degreased using a hydraulic oil press to obtain degreased peanut kernels; Defatted peanut kernels were enzymatically hydrolyzed using glycosylase and protease to obtain enzymatically hydrolyzed peanut kernels; The enzymatically hydrolyzed peanut kernels were subjected to heat treatment and pulverization in sequence to obtain crushed peanuts; The crushed peanuts and light peanut oil are mixed and ground to obtain peanut butter; The ratio of the mass of the crushed peanuts to the volume of the light peanut oil is 100g: 10~20mL.

[0006] Preferably, the pressure of the hydraulic oil pressing device is 60 MPa.

[0007] Preferably, the light peanut oil contains 60% diglycerides by weight.

[0008] Preferably, the degreasing time is 1 hour and the temperature is 25°C.

[0009] Preferably, the heat treatment temperature is 140°C; the heat treatment time is 20 minutes; and the heat treatment includes roasting.

[0010] Preferably, the glycoenzyme includes sucrase.

[0011] Preferably, the grinding includes ball milling.

[0012] The present invention also provides the application of the processing method described above in reducing the energy content of peanut butter and / or improving the storage stability of peanut butter.

[0013] The present invention also provides peanut butter obtained by the processing method described above, wherein the energy of the peanut butter is less than 2000 kJ / 100g.

[0014] Preferably, the peanut butter has an energy content of 1800~1900 kJ / 100g.

[0015] This invention provides a method for processing peanut butter, comprising the following steps: defatting peanut kernels using a hydraulic oil press to obtain defatted peanut kernels; enzymatically hydrolyzing the defatted peanut kernels using glycosylase and protease to obtain enzymatically hydrolyzed peanut kernels; subjecting the enzymatically hydrolyzed peanut kernels to heat treatment and pulverization sequentially to obtain peanut crumbs; mixing the peanut crumbs with light peanut oil and grinding to obtain peanut butter; the mass ratio of the peanut crumbs to the volume of the light peanut oil is 100g:10~30mL. This invention uses a hydraulic oil press to defatt the peanut kernels, effectively reducing the triglyceride content and thus lowering the overall energy level of the product. However, the reduction in oil content weakens the inherent flavor of the peanut kernels and affects the texture and overall quality of the peanut butter. To compensate for the flavor loss caused by the reduced oil content, this invention uses glycosylase and protease to enzymatically hydrolyze the defatted peanut kernels, enhancing the hydrolytic activity of proteins and sugars, increasing the content of free amino acids and reducing sugars, and providing sufficient flavor precursors for the Maillard reaction during subsequent heat treatment. The heat treatment process further promotes the generation of aroma substances and makes the flavor more harmonious. To ensure peanut butter quality and improve its fluidity, this invention mixes heat-treated and pulverized peanut pieces with light peanut oil and grinds them to ensure uniform dispersion of the light peanut oil within the peanut system. Compared to traditional peanut triglycerides, light peanut oil has a lower metabolizable energy value and better interfacial activity. Its addition not only improves the rheological properties, lubricity, and structural stability of peanut butter but also promotes the release and retention of flavor-active substances. During storage, the diglycerides in light peanut oil optimize the oil-solid interface structure, reducing the risk of oil migration and precipitation, effectively inhibiting oil separation. Simultaneously, its emulsifying and dispersing effects slow down lipid oxidation and the loss of antioxidants (such as total phenols and vitamin E), prolonging the retention time of volatile flavor compounds and significantly improving the stability and acceptability of peanut butter in terms of taste, flavor, and nutrition. Therefore, the processing method of this invention, through multi-step synergistic regulation, achieves reduced energy in peanut butter while simultaneously ensuring its sweet and aromatic flavor, textural uniformity, and long-term storage quality stability, providing a reliable technical solution for the industrial production of healthy, high-quality peanut butter. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a flowchart illustrating the processing of peanut butter in Embodiment 1 of the present invention; Figure 2Shear stress in peanut butter with different amounts of light peanut oil added; Figure 3 The apparent viscosity of peanut butter with different amounts of light peanut oil added. Detailed Implementation

[0018] This invention provides a method for processing peanut butter, comprising the following steps: Peanut kernels were degreased using a hydraulic oil press to obtain degreased peanut kernels; Defatted peanut kernels were enzymatically hydrolyzed using glycosylase and protease to obtain enzymatically hydrolyzed peanut kernels; The enzymatically hydrolyzed peanut kernels were subjected to heat treatment and pulverization in sequence to obtain crushed peanuts; The crushed peanuts and light peanut oil are mixed and ground to obtain peanut butter; The ratio of the mass of the crushed peanuts to the volume of the light peanut oil is 100g: 10~30mL.

[0019] The processing method of this invention can reduce the energy of peanut butter, provide sufficient nutrients, and maintain the sweet and fragrant flavor of peanut butter.

[0020] The present invention first uses a hydraulic oil pressing device to degrease peanut kernels to obtain defatted peanut kernels.

[0021] In one embodiment, the pressure of the hydraulic oil pressing device is 60 MPa; the defatting is a restricted defatting; the defatting time is 1 hour, and the temperature is 25°C; the peanut kernels are high-quality peanut kernels with skin. This invention uses a hydraulic oil pressing device to defatt the peanut kernels, which can effectively reduce the triglyceride content in the peanut kernels, thereby reducing the overall energy level of the product, making the product conform to health concepts, and providing a foundation for subsequent flavor development. Furthermore, by applying high pressure to the peanut kernels using hydraulic technology, the oil is efficiently separated, obtaining low-fat peanut raw materials. The hydraulic defatting process can simultaneously obtain high-quality cold-pressed peanut oil, achieving efficient utilization of raw material resources.

[0022] After obtaining defatted peanut kernels, the present invention uses glycosylase and protease to enzymatically hydrolyze the defatted peanut kernels to obtain enzymatically hydrolyzed peanut kernels.

[0023] In one embodiment, the enzymatic hydrolysis of defatted peanut kernels using glycosylase and protease includes soaking the defatted peanuts in an enzymatic hydrolysate containing glycosylase and protease. Specifically, the amount of glycosylase in the hydrolysate is 0.1% wt, and the amount of protease is 0.5% wt; the material-to-liquid ratio (the ratio of the mass of defatted peanut kernels in g to the volume of the hydrolysate in mL) is 1:3; the soaking time is 30 min; and the enzymatic hydrolysis time is 3 h.

[0024] In this invention, proteases are used to hydrolyze the peptide bonds of peanut proteins, generating small peptides and free amino acids, thereby providing a sufficient nitrogen source for the Maillard reaction and Strecker degradation, promoting the release of flavor precursors. Secondly, sucrase is used to hydrolyze sucrose to generate reducing sugars, providing the carbon source required for the reaction and accelerating the formation of flavor compounds. This synergistic enzymatic hydrolysis strategy of proteases and sucrase not only improves the microstructure of low-fat peanuts but also lays the material foundation for flavor enhancement during roasting and oil processing. This invention allows proteases and glycosylases (carbohydrate enzymes) to fully penetrate the peanut interior through enzymatic hydrolysis. This invention enhances the hydrolytic activity of proteins and sugars through enzymatic hydrolysis, increasing the content of free amino acids and reducing sugars, thereby increasing the content of flavor precursors in peanut kernels and providing sufficient flavor precursors for the Maillard reaction during subsequent heat treatment.

[0025] In one embodiment, the glycoenzyme includes sucrase; the protease is a flavor protease; and the enzymatic hydrolysis is dry enzymatic hydrolysis, which involves soaking restricted defatted peanut kernels in an enzymatic hydrolysate for a certain period of time, allowing the peanut kernels to absorb the enzyme solution, and then pouring out the remaining enzymatic hydrolysate to allow the peanut kernels to continue enzymatic hydrolysis. In this invention, dry enzymatic hydrolysis is carried out under relatively low temperature and short time conditions, which can significantly promote the release of flavor precursors in peanuts, including amino acids and polypeptides generated from protein decomposition, as well as flavor precursors formed by sugar participation.

[0026] After obtaining the enzymatically hydrolyzed peanut kernels, the present invention sequentially heat-treats and pulverizes the enzymatically hydrolyzed peanut kernels to obtain crushed peanuts.

[0027] In one embodiment, the heat treatment temperature is 140°C; the heat treatment time is 20 minutes; the above heat treatment conditions are low-temperature, short-time heat treatment conditions. Due to the increased content of flavor precursor substances, the purpose of heat treatment to enhance aroma can be achieved at a lower heat treatment temperature. Low-temperature, short-time conditions are conducive to forming a typical sweet aroma, preserving heat-sensitive nutrients in the oil, avoiding protein damage, burnt flavor formation, and potential harmful substance risks caused by high-temperature heat treatment, while also reducing energy consumption; the heat treatment includes roasting, which enhances the typical roasted peanut aroma. The heat treatment of this invention can further promote the formation of aroma substances and make the flavor more harmonious.

[0028] After the pulverization, the present invention further includes passing the pulverized material through an 80-mesh sieve and collecting the undersize components.

[0029] After obtaining crushed peanuts, the present invention mixes the crushed peanuts with light peanut oil and grinds them to obtain peanut butter.

[0030] In one embodiment, the light peanut oil contains diglycerides; the mass percentage of diglycerides in the light peanut oil is 60%.

[0031] As one implementation method, the grinding includes ball milling, which enables the light peanut oil to be uniformly dispersed in the peanut system, thereby achieving structural reconstruction of the lipid system.

[0032] After grinding, the present invention further includes sealing and packaging the ground material and using an oven method for accelerated storage, with a storage temperature of 63±1℃ and a storage time of 30 days.

[0033] In this invention, the diglycerides in lightly fatty peanut oil have lower metabolizable energy and better interfacial activity compared to traditional triglycerides. Their addition optimizes oil distribution, enhances emulsification, and allows defatted peanut butter to maintain moderate viscosity and good flowability under low shear conditions, improving the continuity and uniformity of the product structure. This not only improves the rheological properties, lubricity, and structural stability of peanut butter but also promotes the release and retention of flavor-active substances. During storage, the diglycerides in lightly fatty peanut oil optimize the oil-solid interface structure, reducing the risk of oil migration and precipitation, effectively inhibiting oil separation. Simultaneously, their emulsifying and dispersing effects slow down lipid oxidation and the loss of antioxidants (such as total phenols and vitamin E), prolonging the retention time of volatile flavor compounds and significantly improving the stability and acceptability of peanut butter in terms of taste, flavor, and nutrition. Furthermore, the excellent emulsifying properties of the diglycerides in lightly fatty peanut oil help to evenly distribute flavor compounds released during enzymatic hydrolysis between the lipid and aqueous phases, thereby enhancing the overall aroma and stabilizing the flavor. Furthermore, the diglycerides in lightly oiled peanut oil synergistically work with flavor precursors generated by enzymatic hydrolysis to promote flavor release under low-temperature conditions. This allows the peanut butter to retain its rich, sweet aroma while avoiding the burnt flavor and heat damage risks associated with high-temperature roasting. In summary, the diglycerides in lightly oiled peanut oil not only replenish some of the oil content and improve the emulsification and rheological properties of the product, but also work with the enzymatic hydrolysis process to promote the generation and uniform distribution of flavor compounds. This provides a systematic and controllable technical solution for developing healthy, high-flavor, structurally stable peanut butter with excellent taste.

[0034] This invention achieves an organic combination of low-fat and flavor enhancement through multi-step synergistic regulation. Specifically, while reducing the energy density of peanut butter, it improves the rheological properties, lubricity, and flavor retention of the peanut butter, while simultaneously ensuring its sweet aroma, textural uniformity, and long-term storage stability. This synergistic improvement in the texture and flavor quality of peanut butter provides a reliable technical solution for the industrial production of healthy, high-quality peanut butter.

[0035] The present invention also provides the application of the processing method described above in reducing the energy content of peanut butter and / or improving the storage stability of peanut butter.

[0036] As one implementation method, improving the storage stability of peanut butter includes at least one of the following: 1) Improve at least one of the following: rheological properties, lubricity, and structural stability of peanut butter; 2) Promotes the release and / or retention of flavor-active substances in peanut butter; 3) Inhibits oil migration and precipitation in peanut butter; 4) It slows down lipid oxidation and the loss of antioxidants; The antioxidants include total phenols and / or vitamin E; the flavor actives include volatile flavor actives.

[0037] The present invention also provides peanut butter obtained by the processing method described above, wherein the energy of the peanut butter is less than 2000 kJ / 100g.

[0038] In one embodiment, the peanut butter has an energy content of 1800~1900 kJ / 100g.

[0039] The peanut butter of this invention is a low-energy, high-diglyceride, sweet and fragrant flavor, stable emulsification, and fine texture peanut butter that combines health benefits with flavor quality. All quality indicators meet national standards, demonstrating significant economic value and market potential.

[0040] To further illustrate the present invention, a peanut butter processing method provided by the present invention will be described in detail below with reference to the accompanying drawings and embodiments, but these should not be construed as limiting the scope of protection of the present invention.

[0041] Example 1 In Example 1, 10% light peanut oil was added to prepare a low-energy, diglyceride-rich flavored peanut butter.

[0042] High-quality, mature peanut kernels free from deterioration and mold were selected as raw materials. These kernels were degreased using a hydraulic oil press to obtain enzymatically hydrolyzed raw materials. The degreased peanut kernels were then soaked in a buffer solution containing sucrase and alkaline protease for enzymatic hydrolysis. The sucrase dosage was 0.1% wt, and the protease dosage was 0.5% wt. The material-to-liquid ratio (degreased peanut mass g: hydrolysate volume mL) was 1:3. The soaking time was 30 min, and the hydrolysis time was 3 h before drying. Subsequently, the hydrolyzed peanut kernels were roasted in a 140℃ peanut roaster for 20 min, then pulverized, and 10% commercially available light peanut oil (containing 60% diglycerides by weight; all diglyceride content mentioned below refers to weight percentages) was added. The mixture was then ball-milled to obtain peanut butter, and storage experiments were conducted on the peanut butter.

[0043] The peanut butter obtained in Example 1 had significantly lower energy than the control group, and its content was slightly lower than that in Examples 2-3.

[0044] The total volatile component content (i.e., rich aroma content) of peanut butter flavored peanuts was 45416.57 μg / kg, which was significantly better than the control group, but slightly lower than that of Examples 2-3.

[0045] This indicates that the addition of 10% light peanut oil reduces calories while helping to lock in flavor compounds and maintain volatile aromas, resulting in a good balance in taste and flavor.

[0046] Example 2 In Example 1, 20% light peanut oil was added to prepare a low-energy, diglyceride-rich flavored peanut butter.

[0047] High-quality, mature peanut kernels free from deterioration and mold were selected as raw materials. These kernels were degreased using a hydraulic oil press to obtain enzymatically hydrolyzed raw materials. The degreased peanut kernels were then soaked in a buffer solution containing sucrase and alkaline protease for 3 hours before drying. Subsequently, the enzymatically hydrolyzed peanut kernels were roasted in a 140℃ peanut roaster for 20 minutes, then pulverized, and 20% commercially available light peanut oil (containing 60% diglycerides) was added. The mixture was then ball-milled to obtain peanut butter, and storage experiments were conducted on the peanut butter.

[0048] Compared to Example 1, increasing the amount of diglycerides further improves the oil-solid interface structure, resulting in a more uniform and stable lipid distribution, thereby enhancing the texture and smoothness of the peanut butter. Simultaneously, 20% light peanut oil can more effectively retain volatile flavor compounds, prolong aroma retention time, and improve overall flavor quality while maintaining low-energy characteristics.

[0049] Comparative Example 1 In Example 1, 30% light peanut oil was added to prepare a low-energy, diglyceride-rich flavored peanut butter.

[0050] High-quality, mature peanut kernels free from deterioration and mold were selected as raw materials. These kernels were degreased using a hydraulic oil press to obtain enzymatically hydrolyzed raw materials. The degreased peanut kernels were then soaked in a buffer solution containing sucrase and alkaline protease for 3 hours before drying. Subsequently, the enzymatically hydrolyzed peanut kernels were roasted in a 140℃ peanut roaster for 20 minutes, then pulverized, and 30% commercially available light peanut oil (containing 60% diglycerides) was added. The mixture was then ball-milled to obtain peanut butter, and storage experiments were conducted on the peanut butter.

[0051] The addition of 30% light peanut oil further optimized the lipid structure of the peanut butter system, improved emulsification stability and oil-solid binding, significantly reduced oil separation, and slowed down the loss of flavor compounds. However, excessive addition of light peanut oil would increase its energy content, thus failing to achieve the desired energy reduction effect.

[0052] Comparative Example 2 Commercially available peanut butter This control group reflects the conventional levels of flavor, energy, and lipid structure in traditional peanut butter and can serve as a benchmark for evaluating performance improvements in low-energy, diglyceride-rich peanut butter.

[0053] Comparative Example 3 High-quality, mature peanut kernels free from spoilage and mold were selected as raw materials. These kernels were degreased using a hydraulic oil press to obtain enzymatically hydrolyzed raw materials. The degreased peanut kernels were then soaked in a buffer solution containing sucrase and alkaline protease for 3 hours before drying. Subsequently, the enzymatically hydrolyzed peanut kernels were roasted in a 140℃ peanut roaster for 20 minutes, then pulverized, and 30% cold-pressed peanut oil was added. The mixture was then ball-milled to produce peanut butter, and storage experiments were conducted on the peanut butter.

[0054] This control group demonstrated the effect of enzymatic hydrolysis on improving the flavor and texture of peanut butter. Enzymatic hydrolysis enhances the reactivity of the protein and carbohydrate system, promotes the Maillard reaction during roasting, and enhances the sweet and aromatic flavor. Adding cold-pressed peanut oil can improve the oil-solid interface structure, but it lacks the low-energy and interfacial activity advantages of light-fat peanut oil, and its resistance to oil separation and oxidation during storage is relatively limited.

[0055] Comparative Example 4 High-quality, mature peanut kernels free from spoilage and mold were selected as raw materials. These kernels were degreased using a hydraulic oil press to obtain enzymatically hydrolyzed raw materials. The degreased peanut kernels were then soaked in a buffer solution containing sucrase and alkaline protease for 3 hours before drying. Subsequently, the enzymatically hydrolyzed peanut kernels were roasted in a 140℃ roaster for 20 minutes, followed by pulverization and ball milling to obtain peanut butter and peanut powder.

[0056] Compared with Comparative Example 2, Comparative Example 3 did not contain any oil. After being ball-milled, it could not be made into a sauce, and its content of flavor substances was not as high as that of the oil-containing sample. This also indicates to some extent that the addition of oil has a flavor-enhancing effect.

[0057] Some technical parameters and indicators of Examples 1-2 and Comparative Examples 1-3 (commercially available peanut butter, peanut butter with +30% triglycerides, and peanut powder without added oil) can be found in Table 1 below.

[0058] Table 1. Some technical parameters and indicators of Examples 1-2 and Comparative Examples 1-3

[0059] Experimental Example 1 This invention utilizes a hydraulic oil press for pressing, with precisely adjustable pressure up to 60 MPa. To increase the proportion of diglycerides (DAG) in the oil phase and partially replace triglycerides (TAG) in subsequent product development, the oil content variation under different defatting pressures (0, 10, 30, and 60 MPa) was systematically measured. Results showed that as the hydraulic pressure increased, the oil content gradually decreased, and the oil release efficiency significantly improved. The defatting effect was most significant at 60 MPa, achieving maximum oil separation while maintaining basic sample structural stability, which is beneficial for obtaining peanut butter rich in diglycerides. Therefore, considering oil content, oil separation efficiency, and processing feasibility, 60 MPa was ultimately selected as the optimal pressing pressure.

[0060] Table 2. Oil and protein content of peanuts subjected to different defatting pressures.

[0061] Experimental Example 2 Defatted peanut kernels obtained by pressing with a hydraulic oil press at a pressure of 60 MPa were mixed with 30% light peanut oil (containing 60% diglycerides) and ground separately using a colloid mill and a ball mill. The particle size was compared. The results are shown in Table 3. The results show that the peanut butter obtained by ball milling has a finer particle size, indicating that the ball milling process can significantly improve the degree of grinding of the raw materials.

[0062] Table 3. Particle size of peanut butter obtained by different grinding methods

[0063] Experimental Example 3 Defatted peanut kernels were obtained by pressing with a hydraulic oil press at a defatting pressure of 60 MPa. Subsequently, different temperatures (120, 140, and 160 °C) and roasting times of 20 min were selected to measure and analyze the volatile flavor compounds contributing to the color. The results are shown in Table 4. The results show that this invention, by comprehensively analyzing the changes in flavor compounds and color during the roasting process of low-fat peanuts, and through systematic measurement and analysis of defatted peanut kernels at 60 MPa under different temperature conditions, found that roasting at 140 °C for 20 min was the most suitable. Under these conditions, the L, a, and b values ​​of the peanuts were 66.8, 4.7, and 18.3, respectively, and the color was light brown with high visual appeal, indicating that the roasting temperature could promote the Maillard reaction without causing excessive browning or bitterness.

[0064] Table 4. Content and color of volatile flavor compounds in peanuts roasted at different temperatures.

[0065] Test Example 4 Defatted peanut kernels were obtained by pressing with a hydraulic oil press at a defatting pressure of 60 MPa. The roasting temperature was 140℃, and the roasting times were 10 min, 20 min, and 30 min. The volatile flavor compounds contributing to the color were measured and analyzed, and the results are shown in Table 5. The results showed that the content of volatile flavor compounds increased with increasing roasting time, but the increase was not significant from 20 min to 30 min; simultaneously, the color brightness L... Decrease, a and b Excessive browning may occur after 30 minutes. Considering both flavor and color, 140℃ for 20 minutes provides a good balance between rich flavor and suitable color, so 20 minutes was ultimately chosen.

[0066] Table 5. Content and color of volatile flavor compounds in peanuts roasted for different times.

[0067] Comparison of peanut butter quality in Experimental Example 5, Example 1, Example 2, and Comparative Example 1 The amount of light peanut oil added is one of the important parameters affecting the quality of peanut butter. See Table 6 below.

[0068] Table 6 shows the oil content of peanut butter with different amounts of light peanut oil added.

[0069] As shown in Table 6, the oil content of peanut butter prepared from defatted peanuts varies significantly after adding different amounts of light peanut oil. Specifically, when the amount of light peanut oil added reaches 30%, the oil content of the peanut butter is close to that of commercially available peanut butter. This indicates that a high content of light peanut oil can, to some extent, compensate for the reduction in oil content caused by defatting, thus maintaining the energy-reducing characteristics while approaching the oil content of traditional products. See Table 7 below.

[0070] Table 7 Total diglyceride content of peanut butter with different amounts of light peanut oil added.

[0071] As shown in Table 3, the total diglyceride content in peanut butter increases significantly with the increase of the amount of light-fat peanut oil added. This indicates a clear positive correlation between the amount of light-fat peanut oil added and the total diglyceride content in peanut butter, providing a basis for precise control of the physicochemical properties and quality of peanut butter by adjusting the amount of light-fat peanut oil added. See Table 8 below.

[0072] Table 8. Centrifugal oil absorption rate of peanut butter with different amounts of light peanut oil added.

[0073] As shown in Table 8, the addition of lightly fatty peanut oil significantly reduced the oil separation rate of peanut butter. Commercially available peanut butter with no added lightly fatty peanut oil had a high oil separation rate, while the addition of lightly fatty peanut oil significantly reduced the oil separation rate, especially at low concentrations (10%) where oil separation was almost nonexistent. As the lightly fatty peanut oil content increased to 20% and 30%, the oil separation rate slightly increased, but remained far below the levels of commercially available peanut butter. This indicates that lightly fatty peanut oil can effectively inhibit oil separation in peanut butter, improving product stability and emulsifying properties.

[0074] See below Figure 1 and Figure 2 .according to Figure 1 and Figure 2 It can be seen that the addition of lightly fatty peanut oil affects the static rheological behavior of peanut butter. With increasing lightly fatty peanut oil content, the viscosity of the peanut butter increases significantly at low shear rates, while the viscosity change at high shear rates tends to be gradual, exhibiting more stable shear-thinning characteristics. However, when the amount of lightly fatty peanut oil added is 10%, the peanut butter viscosity is too high and the flowability is insufficient, making it difficult to form a measurable rheological curve. See Table 9 below.

[0075] Table 9: Flavor of peanut butter with different amounts of light peanut oil added.

[0076] In summary, the introduction of lightly fatty peanut oil significantly increased the total volatile matter content in peanut butter, indicating a clear positive regulatory effect on the construction of a rich aroma flavor. This effect mainly stems from the high polarity of diglycerides in lightly fatty peanut oil and their structural regulation ability in the system, which makes the oil exhibit stronger solubility, adsorption, and retention capacity relative to flavor compounds, thereby effectively reducing the loss of volatile flavor substances during processing and storage. Simultaneously, the diglycerides in lightly fatty peanut oil improve the micro-dispersion state and oil phase stability of peanut butter, providing favorable conditions for the uniform distribution and sustained release of flavor substances. With increasing addition amount, the system's capacity to carry flavor substances gradually increases, but at higher addition levels (20%~30%), the total volatile matter content tends to stabilize, indicating that the system has a certain upper limit for flavor enrichment. Overall, the appropriate addition of lightly fatty peanut oil not only helps to enhance the intensity of the rich aroma flavor of peanut butter but also achieves synergistic improvement in flavor quality without relying on additional flavorings, providing an effective technical path for flavor optimization of structure-regulated peanut butter products. See Table 10 below.

[0077] E(kJ / 100g) = 37 × ordinary fat content (g / 100g) + 20 × diglyceride content (g / 100g) + 17 × protein content (g / 100g) + 17 × digestible carbohydrate content (g / 100g) Table 10 Energy Calculations for Peanut Butter with Different Amounts of Light Peanut Oil Added

[0078] The introduction of low-fat peanut oil has a significant impact on the energy structure of peanut butter. On the one hand, the diglycerides in low-fat peanut oil have a lower metabolizable energy value than traditional triglycerides, thus significantly reducing the total energy of the product under the same fat substitution conditions. On the other hand, the addition of low-fat peanut oil is usually accompanied by a reduction in fat content and an adjustment in the ratio of protein and carbohydrates, resulting in a more balanced energy composition. This regulation not only achieves energy reduction while maintaining the flavor and texture of peanut butter, but also provides a scientific basis for the development of functional and health-oriented products, demonstrating significant application value.

[0079] Storage stability is one of the important parameters of peanut butter quality. We conducted storage experiments on peanut butter with different treatments at a storage temperature of 63℃ for 30 days. See Table 11 below.

[0080] Table 11 Changes in acid value (mg / g) during storage

[0081] The changes in acid value during storage reveal that different oil systems significantly impact the hydrolytic stability of peanut butter. Overall, the acid value of commercially available peanut butter and the +30% cold-pressed peanut oil group increased most rapidly with storage time, with a particularly pronounced increase in the later stages. This indicates that triglyceride-type oils are more prone to hydrolysis during storage, leading to the continuous accumulation of free fatty acids. In contrast, the increase in acid value in the peanut butter system with added light peanut oil was significantly suppressed, and the rate of acid value increase gradually decreased with increasing amounts of light peanut oil, demonstrating better hydrolytic stability. This phenomenon is mainly attributed to the polarity and structuring effect of diglycerides in light peanut oil, which reduces the proportion of free oil phase in the system, restricts the migration of water in the oil phase, and thus weakens residual lipase activity and non-enzymatic hydrolysis. Simultaneously, the interfacial regulation effect of diglycerides in light peanut oil makes it difficult for fatty acids to be released from the glycerol skeleton, delaying the formation of free fatty acids. In summary, the introduction of light-fat peanut oil effectively slows down the increase in acid value of peanut butter during storage, improving the product's storage stability. Cold-pressed peanut oil, due to the retention of more active ingredients and hydrolyzed sensitive structures, exhibits an acid value increase trend similar to or even slightly higher than that of commercially available peanut butter. See Table 12 below.

[0082] Table 12 Changes in peroxide value (mmol / kg) during storage

[0083] Peroxide value results showed that different oil systems significantly affected lipid oxidation during the storage period of peanut butter. With prolonged storage, the peroxide value of all treatment groups increased, but commercially available peanut butter showed the fastest increase and the worst oxidative stability. The samples with added light peanut oil showed a significant overall decrease in peroxide value, and the rate of increase gradually slowed with increasing amounts of light peanut oil. The 30% light peanut oil group exhibited the best oxidative stability. In contrast, while adding 30% cold-pressed peanut oil delayed oxidation to some extent, the effect was weaker than that of the group with the same amount of light peanut oil. These results indicate that diglycerides in light peanut oil can effectively inhibit primary lipid oxidation and improve the storage stability of peanut butter by improving the system structure and interfacial properties. See Table 13 below.

[0084] Table 13 Changes in Vitamin E (mg / kg) during storage

[0085] Vitamin E (VE) content showed a continuous decreasing trend across all treatment groups with prolonged storage time, indicating that lipid oxidation continuously depletes antioxidant components during storage. Commercially available peanut butter showed the most significant VE decrease, with the largest reduction after 30 days, suggesting a high degree of oil oxidation and limited endogenous antioxidant capacity in its system. Samples with added light peanut oil exhibited significantly higher VE retention rates throughout the storage period than the commercially available group, and the rate of VE decline gradually slowed with increasing amounts of light peanut oil. The 30% light peanut oil group showed the best VE retention capacity. This is mainly related to the fact that diglycerides in light peanut oil improve the continuous phase structure of the lipids, reduce the oxygen diffusion rate, and enhance system stability. In contrast, although the addition of 30% cold-pressed peanut oil resulted in a higher initial VE content, its decrease during storage was still significant, indicating that simply increasing the initial VE level is insufficient to effectively inhibit oxidative consumption, while diglycerides in light peanut oil play a more crucial role in structural regulation and oxidation retardation.

[0086] See Table 14 below for the changes in total phenols during storage.

[0087] Table 14 Changes in total phenols (mg GAE / kg) during storage

[0088] During storage, the total phenol content of peanut butter in each treatment group showed a decreasing trend, reflecting the continuous consumption of phenolic substances in the system during oxidation and free radical scavenging. Commercially available peanut butter showed the largest decrease in total phenol content, indicating that its oil structure is relatively loose and easily facilitates oxidation. The samples with added light peanut oil maintained significantly better total phenol content than the commercially available group, and the rate of decrease gradually slowed with increasing addition amount, indicating that the diglycerides in light peanut oil can effectively delay the loss of phenolic substances by improving the oil-solid interface structure, enhancing oil dispersion stability, and reducing oxygen migration efficiency. In contrast, although the samples with added 30% cold-pressed peanut oil had a higher initial total phenol content, the decrease in total phenol content during storage was still significant, indicating that relying solely on high-phenol oils cannot fully guarantee the system's antioxidant capacity. The diglycerides in light peanut oil play a key role in structural regulation and oxidation inhibition, thereby improving the long-term storage stability of peanut butter.

[0089] See Table 15 below for the changes in oil separation rate during storage.

[0090] Table 15 Changes in centrifugal oil separation rate during storage.

[0091] During storage, the oil separation rate of peanut butter gradually increased, but different oil systems showed significant differences. Commercially available peanut butter had a high initial oil separation rate (11%), which increased rapidly with storage time, indicating a loose oil phase structure and a strong tendency for oil-water separation. In contrast, the sample with added light peanut oil had a significantly lower initial oil separation rate than the commercially available group, and increased slowly with storage time. The higher the amount added, the lower the oil separation rate, indicating that the diglycerides in light peanut oil can improve the emulsification stability between the oil and the solid phase, forming a denser structured network, thereby limiting the free migration and separation of oil. In the light peanut oil system, even after 30 days of storage, the oil separation rate was still much lower than that of commercially available peanut butter, indicating that the diglycerides in light peanut oil play a significant role in inhibiting oil separation and maintaining the structural stability of peanut butter. Although the initial oil separation rate of the group with added 30% cold-pressed peanut oil was close to that of commercially available peanut butter, the rate of increase was slightly slower, indicating that while cold-pressed oil has a certain emulsifying effect, it lacks the structural strengthening advantage of light peanut oil. In summary, the introduction of light peanut oil effectively inhibited oil precipitation during peanut butter storage, improving the product's structural stability and storage quality.

[0092] See Table 16 below for the changes in flavor during storage. Table 16 Flavor Changes During Storage

[0093] During storage, the total volatile matter (flavor compounds) content of peanut butter showed a decreasing trend, indicating that the flavor gradually weakened during storage. Commercially available peanut butter showed the most significant flavor decline, with low initial content and a rapid decrease over time, suggesting a relatively limited number of flavor precursors and poor storage stability. In contrast, peanut butter with added light peanut oil maintained a significantly higher level of flavor retention, and the rate of decline in total volatile matter gradually slowed with increasing amounts of light peanut oil. The 30% light peanut oil group maintained a high flavor content even after 30 days. This is mainly attributed to the fact that the diglycerides in light peanut oil improved the oil-solid phase structure of peanut butter, forming a denser network, reducing the escape of volatile flavor compounds, and maintaining the stability of flavor precursors produced by enzymatic hydrolysis. Although the initial flavor of the 30% cold-pressed peanut oil group was higher, the decline during storage was significant, indicating that simply adding exogenous oil cannot effectively delay flavor loss, while the structural regulation effect of diglycerides in light peanut oil has a clear advantage in prolonging the flavor retention of peanut butter. Overall, light peanut oil not only enhances the storage stability of low-fat peanut butter, but also significantly slows down flavor decay, improving the product's sensory quality and storage value.

[0094] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method of processing peanut butter, characterized by, Includes the following steps: Peanut kernels were degreased using a hydraulic oil press to obtain degreased peanut kernels; Defatted peanut kernels were enzymatically hydrolyzed using glycosylase and protease to obtain enzymatically hydrolyzed peanut kernels; The enzymatically hydrolyzed peanut kernels were subjected to heat treatment and pulverization in sequence to obtain crushed peanuts; The crushed peanuts and light peanut oil are mixed and ground to obtain peanut butter; The ratio of the mass of the crushed peanuts to the volume of the light peanut oil is 100g: 10~20mL.

2. The processing method according to claim 1, characterized in that, The pressure of the hydraulic oil pressing device is 60 MPa.

3. The processing method according to claim 1, characterized in that, The light peanut oil contains 60% diglycerides by weight.

4. The processing method according to claim 1, characterized in that, The degreasing process takes 1 hour at a temperature of 25°C.

5. The processing method according to claim 1, characterized in that, The heat treatment temperature is 140°C; the heat treatment time is 20 minutes; the heat treatment includes roasting.

6. The processing method according to claim 1, characterized in that, The glycoenzymes include sucrase.

7. The processing method according to claim 1, characterized in that, The grinding includes ball milling.

8. The application of the processing method according to any one of claims 1 to 7 in reducing the energy content of peanut butter and / or improving the storage stability of peanut butter.

9. The peanut butter obtained by the processing method according to any one of claims 1 to 7, characterized in that, The energy of the peanut butter is less than 2000 kJ / 100g.

10. The peanut butter according to claim 9, characterized in that, The peanut butter has an energy content of 1800~1900 kJ / 100g.

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