Preparation method of high-stable high-oleic peanut milk based on synergistic effect of natural oil body and glycosylated protein

Abstract

The application discloses a kind of preparation methods of high-stable high-oleic peanut milk based on natural oil body and glycosylation protein synergistic effect, belong to food industrialization technical field.The preparation methods include the following steps: in step 1, peanut kernels are weighed and baked;in step 2, red skin is removed and soaked;in step 3, water is added and mixed to beat pulp;in step 4, defatted gauze is used to filter and homogenize;in step 5, ultrasonic power is treated to homogenize;in step 6, iota-carrageenan is added and high-speed shearing is performed;in step 7, mogroside is added and high-speed shearing is performed;and in step 8, high-oleic peanut milk with strong stability is obtained.The preparation methods select specific baking temperature, ultrasonic power, carrageenan concentration and the numerical range of seasoning addition amount, reduce the particle size of oil body and protein electric potential, unfold protein structure, achieve stable combination of oil body, sugar and protein, synergistic effect, improve dispersion stability, thermal stability, storage stability, freeze-thaw stability, oxidation stability and salt ion stability, and comprehensively improve the stability of high-oleic peanut milk.

Description

Technical Field

[0001] This invention relates to the field of food industrialization, and in particular to a method for preparing highly stable, high-oleic peanut milk based on the synergistic effect of natural oils and glycosylated proteins. Background Technology

[0002] Oleic acid is a monounsaturated fatty acid that plays an important role in the human body and can be obtained through food. Oleic acid has many benefits, including lowering cholesterol, acting as an antioxidant, promoting cardiovascular health, improving skin health, enhancing brain function, improving digestive health, reducing the risk of diabetes, promoting bowel movements, and lowering blood pressure.

[0003] Peanuts, belonging to the legume family and the genus Arachis, are annual herbaceous plants with a long history of cultivation and a wide distribution. They are an important source of protein, fat, carbohydrates, and other trace elements for the human body. Peanut kernels contain 40-58% fat and 20-28% protein, and are rich in various vitamins, phytosterols, resveratrol, flavonoids, and other bioactive components, making them a natural raw material with great development potential in the food industry.

[0004] High-oleic peanuts refer to peanut varieties with significantly increased oleic acid content. With the continuous improvement of breeding and cultivation techniques, high-oleic peanut varieties have achieved large-scale promotion. Compared with the oleic acid content of ordinary peanuts (around 35%-69%), high-oleic peanuts have an oleic acid content of ≥75% of the total fatty acids and an oleic acid to linoleic acid ratio of ≥10. This not only greatly improves the oxidative stability of peanut oils, but also shows superior health value in reducing cholesterol, enhancing insulin sensitivity, improving inflammation, and reducing trans fatty acid production.

[0005] Therefore, high-oleic peanuts, with their excellent nutritional value and health benefits, are gradually becoming a new choice for people's healthy diet. High-oleic peanut milk, as a type of plant protein beverage, is a flavored beverage made from high-oleic peanut kernels through modern food processing techniques such as soaking, grinding, blending, homogenization, and sterilization. It contains rich nutritional and health value, meets consumers' pursuit of high-quality beverages, and market demand continues to increase.

[0006] However, high-oleic peanut milk is essentially a colloidal or emulsion system composed of "protein-fat-water" (the fat will be referred to as oil body hereafter), which is thermodynamically unstable. This instability will be amplified during heating, sterilization, cooling, and long-term storage, mainly causing the following types of problems: 1. Physical stability issues: This is the most direct and common problem, including fat floating and layering, protein flocculation, precipitation and clumping, abnormal system viscosity and gelation, increased particle size and wider distribution, etc.

[0007] 2. Deterioration of sensory quality: Subsequent problems caused by instability include darkening, dulling, and uneven color; rough texture, grainy texture, poor emulsification; deterioration of flavor; and the appearance of oxidized or rancid tastes, etc.

[0008] 3. Decreased chemical and nutritional stability: Further problems may arise, such as oxidative rancidity of oils, reduced nutritional value of proteins, pH drift, and system imbalance.

[0009] 4. Processing and shelf-life risks: Instability can also lead to increased viscosity, scaling or wall adhesion after sterilization, short shelf life, large quality fluctuations, and greater reliance on stabilizers, increasing costs and risks.

[0010] However, issues such as unstable composition, easy precipitation, and impact on nutritional value, efficacy, and taste have hindered the development of high-oleic peanut milk in the food industrialization field.

[0011] In recent years, researchers have conducted in-depth research on improving the stability of plant protein beverages, from optimizing processing technology and homogenization techniques to constructing stabilizer compound systems and protein modification. They have found that the composition of raw materials, the type of emulsifier, and physical field treatment are important factors affecting the stability of plant protein dairy beverages. Summary of the Invention

[0012] The purpose of this invention is to provide a method for preparing highly stable high-oleic peanut milk based on the synergistic effect of natural oils and glycosylated proteins, thereby reducing the thermodynamic instability that easily occurs in peanut milk during processing and storage, overcoming the problems in the prior art, and achieving the goal of improving the dispersion stability, thermal stability and storage stability of high-oleic peanut milk.

[0013] This invention provides a method for preparing highly stable high-oleic peanut milk based on the synergistic effect of natural oils and glycosylated proteins, comprising the following steps, where all parts in the following text are parts by weight: Step 1: Weigh 100 portions of high-oleic peanut kernels and bake at 140℃~160℃ for 20 minutes; Step 2: Remove the red skin from the peanuts and soak them in 4℃ deionized water for 12 hours; Step 3: Add deionized water to the soaked peanuts at a concentration ratio of 1:8, mix and blend into a paste; Step 4: The pulped liquid is filtered through four layers of degreased gauze and homogenized using a high-pressure homogenizer at 25℃ and 60 MPa. Step 5: The filtered liquid is treated with ultrasonic power of 90W~270W in an ice water bath and homogenized using a high-pressure homogenizer at 25℃ and 60 MPa. Step 6: Add 0.16%~0.32% ι-carrageenan by mass to the homogenized liquid and shear at high speed at 6000 r / min for 1 min; Step 7: Add 0.1%~0.2% mogroside to the sheared liquid and shear at a high speed of 6000 r / min for 1 min; Step 8: Finally, a highly stable high-oleic peanut milk is obtained.

[0014] Furthermore, in the above-mentioned method for preparing highly stable high-oleic peanut milk based on the synergistic effect of natural oils and glycosylated proteins, the baking temperature in step 1 is 150°C.

[0015] Furthermore, in the above-mentioned method for preparing highly stable high-oleic peanut milk based on the synergistic effect of natural oil and glycosylated proteins, the ultrasonic power in step 5 is 210W.

[0016] Furthermore, in the above-mentioned method for preparing highly stable high-oleic peanut milk based on the synergistic effect of natural oils and glycosylated proteins, in step 6, the mass concentration of ι-carrageenan is 0.16%.

[0017] Furthermore, in the above-mentioned method for preparing highly stable high-oleic peanut milk based on the synergistic effect of natural oils and glycosylated proteins, the mass concentration of mogroside in step 7 is 0.2%.

[0018] Furthermore, in the above-mentioned method for preparing highly stable high-oleic peanut milk based on the synergistic effect of natural oil and glycosylated protein, in step 1, 100 parts of high-oleic peanut kernels, 25 parts of pumpkin seed oil, and 25 parts of glycosylated pea protein isolate are weighed.

[0019] The method for preparing highly stable high-oleic peanut milk based on the synergistic effect of natural oils and glycosylated proteins provided by this invention has the following advantages compared to existing technologies: 1. This invention roasts high-oleic peanut kernels at a temperature range of 140℃ to 160℃, which enhances the aroma and appearance of the high-oleic peanut kernels, increases the whiteness value of the subsequently produced high-oleic peanut milk, optimizes the flavor and color of the high-oleic peanut milk, indirectly improves its thermal stability, and lays the foundation for the subsequent development of the protein structure in the high-oleic peanut milk, promoting its development at the oil-water interface to form a stable network structure and interfacial film.

[0020] 2. This invention uses ultrasonic power of 90W~270W to reduce the particle size and potential of oil and protein in high oleic acid peanut milk, promotes stronger interaction between molecular particles, making them difficult to separate, and improves the dispersion stability and thermal stability of high oleic acid peanut milk. Furthermore, by unfolding the protein structure, it enhances the solubility, surface hydrophobicity and emulsifying properties of the protein, laying the groundwork for subsequent binding and further improvement of stability.

[0021] 3. This invention adds 0.16%~0.32% by mass of ι-carrageenan, which binds to the surface charge of the oil body and combines with the unfolded protein structure through electrostatic interaction. Through steric hindrance and electrostatic repulsion, a stable and dense three-dimensional network is formed with the oil body as the intersection and the protein and ι-carrageenan as the lines, thereby improving the dispersion stability and storage stability of high oleic acid peanut milk.

[0022] 4. This invention adds 0.1% to 0.2% mogroside, which has the advantages of being naturally zero-calorie and not raising blood sugar. After its addition, it balances the taste and health benefits of high-oleic peanut milk.

[0023] 5. This invention achieves a strong synergistic effect between natural oil and glycosylated protein by adding pumpkin seed oil and glycosylated pea protein isolate to high oleic peanut kernels, and by superimposing the effects of baking temperature, ultrasonic power, carrageenan concentration, etc., thereby improving the thermal stability, freeze-thaw stability, oxidative stability and salt ion stability of high oleic peanut milk.

[0024] In summary, this invention reduces the potential of oil and protein, decreases the particle size of oil and protein, expands the protein structure, and improves protein solubility, surface hydrophobicity, and emulsifying properties by selecting specific ranges of baking temperature, ultrasonic power, carrageenan concentration, and seasoning addition. This allows the oil in peanut milk to bind with each other through sugars, and the protein to bind to sugars, achieving a stable combination and synergistic effect among oil, sugars, and proteins. Consequently, it enhances dispersion stability, thermal stability, storage stability, freeze-thaw stability, oxidative stability, and salt ion stability, comprehensively improving the stability of high-oleic peanut milk. Attached Figure Description

[0025] Figure 1 A comparison of the effects of roasting temperature on the appearance (A) and aroma (B) of high-oleic peanut kernels; Figure 2 A bar graph showing the effect of ultrasonic power on the potential (A), particle size (B), solids content (C), centrifugal sedimentation rate (D), and centrifugal stability coefficient (E) of high oleic peanut milk. Figure 3 A comparison of the potential (A), particle size (B), and appearance (C) of high-oleic peanut milk after heating with ultrasonic power; Figure 4 A comparison chart of the potential (A), particle size (B), particle size distribution (C), and centrifugal sedimentation rate (D) of ι-carrageenan on high oleic peanut milk; Figure 5 Comparison of ι-carrageenan on the 7-day storage stability (potential A, particle size B, and appearance C) of high oleic peanut milk; Figure 6 Comparative chart of sensory evaluation analysis of different peanut milk products; Figure 7 A comparative chart showing the analysis of potential (A), particle size (B), particle size distribution (C), and centrifugal sedimentation rate (D) of different peanut milk products; Figure 8 A comparative chart showing the 7-day storage stability (potential A, particle size B, and particle size distribution C) of different peanut milk products. Detailed Implementation Example

[0026] This invention, based on the synergistic effect of natural oils and glycosylated proteins, develops a method for preparing highly stable high-oleic peanut milk. The specific implementation method is as follows: Step 1: Weigh out 100 portions of high-oleic peanut kernels and bake at 150℃ for 20 minutes.

[0027] Roasting temperature is a key factor affecting the sensory quality of high oleic peanut milk, specifically in terms of the appearance and aroma of the peanut kernels after roasting. When the roasting temperature exceeds 70°C, the peanut kernels undergo the Maillard reaction, generating rich aroma substances, which significantly improves their edible quality.

[0028] Figure 1 Image A shows the appearance of high-oleic peanuts at different roasting temperatures. After peeling, high-oleic peanuts roasted at 140-150℃ have a slight raw peanut aroma and a slightly yellow color. At 160℃, they begin to have a roasted aroma and develop a caramel color. Compared to other temperatures, 140-160℃ yields the best appearance and aroma, with a pleasant roasted fragrance and delicious taste. However, as the roasting temperature continues to rise, at 180℃, the peanuts develop a burnt taste, which is unpleasant.

[0029] like Figure 1 As shown in Figure B, the response values ​​of multiple sensors of the electronic nose were further converted into a set of indicators through principal component analysis after dimensionality reduction. The sum of the variance contribution rates of the first principal component (39.30%) and the second principal component (28.00%) in the principal component analysis of roasted peanuts was 67.30%. The distribution of different scatter points showed significant differences between peanuts roasted at different temperatures (p<0.05): peanuts roasted at 150℃~160℃ exhibited a higher degree of aroma overlap, with a fully released peanut flavor; while peanuts roasted at 140℃~150℃ showed a higher degree of aroma overlap, with a more pronounced roasted aroma. Overall, peanuts roasted at 150℃ have a suitable appearance and roasted aroma.

[0030] Color is an important sensory indicator affecting the market acceptance of plant-based milk beverages. The L*, a*, and b* values ​​measured by a colorimeter are used to measure the color of the sample: L* represents brightness, and a higher value indicates a brighter sample; a* and b* together determine the hue, with a positive value of a representing the degree of red and a negative value representing the degree of green, and a positive value of b representing the degree of yellow and a negative value representing the degree of blue, and the depth of the corresponding color is determined by the magnitude of the absolute value.

[0031] The experimental results of the effect of baking temperature on the whiteness of high oleic peanut milk show that as the baking temperature increases, the color of peanut milk first becomes bright and then gradually darkens. The higher the baking temperature, the greater the decrease in brightness. The peanut milk baked at 150℃ is the brightest (L* value is 81.60). According to a* and b*, the peanut milk shows a trend of turning greenish-yellow. The WH of peanut milk is the largest when baked at 150℃ (80.96), and the WH of peanut milk is the smallest when baked at 180℃ (57.32). The high oleic peanut milk baked at 150℃ is the whitest and has the highest brightness.

[0032] In this embodiment, the optimal temperature value of 150℃ was selected from 140℃ to 160℃ through experiments. Roasting high-oleic peanut kernels at 150℃ improved their aroma and appearance, increased the whiteness of the subsequently produced high-oleic peanut milk, optimized the flavor and color of the high-oleic peanut milk, indirectly improved its thermal stability, and laid the foundation for the subsequent development of the protein structure in the high-oleic peanut milk, promoting the formation of a stable network structure and interfacial film at the oil-water interface.

[0033] Step 2: Remove the red skin from the peanuts and soak them in deionized water at 4℃ for 12 hours. Because the clotting factor in the peanut skin is a procoagulant that inhibits fibrinolysis, it is not suitable for middle-aged and elderly people, those with high blood pressure, arteriosclerosis, or high blood viscosity to consume in large quantities. Therefore, it is best to remove the red skin when processing peanuts. Deionized water achieves high purity by removing ions and dissolved inorganic substances from water. It is mainly produced through technologies such as ion exchange resins, reverse osmosis, electrolysis, and distillation. Peanuts soaked in deionized water have more readily absorbed and utilized nutrients by the body, especially for people with sensitive digestive systems.

[0034] Step 3: After soaking, add deionized water at a concentration ratio of 1:8 and mix and blend. The 1:8 water ratio reduces the viscosity of the liquid, facilitates thorough blending, ensures a smooth consistency and good fluidity, and prevents premature protein denaturation, oil oxidation, and burnt taste caused by localized high temperatures, thus preserving the original flavor and nutrients of the raw materials. Sufficient water allows peanut protein and oil to be evenly dispersed, which is beneficial for the formation of a stable emulsion in subsequent homogenization processes, alleviates thermodynamic instability, and reduces fat buoyancy and protein precipitation during storage. Ordinary tap water contains metal ions such as calcium and magnesium, which can damage the colloidal stability of proteins, promote protein flocculation, and accelerate oil oxidation. Deionized water removes mineral ions, eliminates the negative impact of ions, and enhances the stability of the emulsion, reducing problems such as stratification, sedimentation, and oxidation of peanut milk during storage from the initial processing stage.

[0035] Step 4: The pulped liquid is filtered through four layers of degreased gauze and homogenized using a high-pressure homogenizer at 25℃ and 60 MPa. Peanut pulping produces solid residues such as seed coat fragments, coarse fibers, and incompletely broken kernel particles. The four layers of gauze create a gradient filtration pore size, effectively trapping large particles and allowing only fine proteins, oils, and the pulp to pass through, preventing a grainy or gritty texture in the finished product and ensuring a smooth mouthfeel. Coarse fibers and large particles are one of the causes of sedimentation and stratification during peanut milk storage. Filtering these substances in advance significantly reduces the probability of bottom sedimentation in the finished product, improving the overall stability of the emulsion and meeting the process objective of controlling thermodynamic instability. Furthermore, due to its inherent properties, the degreased gauze is free of oil, impurities, and fluorescent agents, and its chemical properties are stable, preventing the introduction of odors, foreign objects, or harmful substances into the liquid, meeting food production hygiene requirements. The gauze fibers are breathable and permeable to water, resulting in a high filtration rate. Stable and less prone to clogging like dense filter cloth; single-layer gauze has a larger pore size, resulting in more residue leakage; five layers or more result in slow filtration speed, low production efficiency, and are prone to excessive retention of fine particles and loss of raw materials. Four layers form a gradient filter layer, balancing filtration accuracy and flow speed, achieving the required interception effect, while ensuring continuous operation of the production line and balancing quality and capacity; peanut slurry surface will carry some free floating oil, and the gaps between the gauze fibers can adsorb and retain some of the free oil, achieving a mild degreasing effect. Reducing free oil reduces the risk of subsequent oil aggregation, floating and stratification, and oxidation and rancidity, further improving product shelf stability; after filtration, the particle size and uniformity of the liquid are consistent, making it easier to control the process parameters of subsequent blending, homogenization, sterilization and other processes, and reducing the quality difference between batches of finished products.

[0036] Step 5: The filtered liquid is treated with 210W ultrasonic power in an ice-water bath and homogenized using a high-pressure homogenizer at 25℃ and 60 MPa.

[0037] like Figure 2As shown in Figure A, potential, particle size, solids content, centrifugal sedimentation rate, and centrifugal stability coefficient are all important indicators affecting the dispersion stability of peanut milk. Compared with the unultrasonicated version, peanut milk carries the most negative charge at 90 W and 210 W. Figure 2 As shown in Figure B, the peanut milk had the smallest particle size (330.43 nm and 335.83 nm) at ultrasonication of 90 W and 210 W, and the largest particle size (393.57 nm) at ultrasonication of 270 W. Figure 2 As shown in C and D, the solid content of peanut milk decreased significantly at 90W, 210W, and 270W (p<0.05). The centrifugal sedimentation rate of peanut milk was lowest at 90W and 210W, which were 5.20% and 5.60%, respectively, which were 2.58% and 1.18% lower than that of untreated peanut milk.

[0038] According to Stokes' law, the settling velocity of particles is directly proportional to the square of their diameter; the larger the particle size, the faster the settling velocity. Therefore, the effects of 90W and 210W ultrasound on the particle size and centrifugal sedimentation rate of peanut milk are consistent. Compared with no ultrasound, the ultrasound intensity affects the secondary and tertiary structure of peanut proteins, altering their fluorescence intensity and surface hydrophobicity. Ultrasound significantly changes the particle size of peanut oil, causing it to decompose into a more uniform state. Figure 2 The centrifugal stability coefficient of peanut milk indicates that it is most stable at ultrasonic levels of 90W and 210W. At 270W, the negative charge of the peanut milk decreases, the particle size increases, and the centrifugal sedimentation rate increases, indicating that 270W ultrasound is detrimental to peanut milk stability. Therefore, ultrasonic powers of 90W and 210W are beneficial for improving the stability of peanut milk.

[0039] The potential, particle size, and appearance of peanut milk after heating are important factors affecting its thermal stability. Figure 3 Figures A and B show the dispersion stability of high-oleic peanut milk after heating with different ultrasonic powers. The largest particle size of the peanut milk was observed at 90 W (416.17 nm), while the smallest particle size was observed at 210 W (361.2 nm). Figure 3 The results showed that the peanut milk did not separate into layers before and after heating, indicating that it has good thermal stability. Therefore, an ultrasonic power of 210W has a beneficial effect on the stability of peanut milk.

[0040] In this embodiment, the optimal ultrasonic power of 210W was selected from 90W to 270W through experiments. By using 210W ultrasonic power, the particle size and potential of oil and protein in high oleic acid peanut milk were reduced, which promoted stronger interaction between molecular particles, making them difficult to separate. This improved the dispersion stability and thermal stability of high oleic acid peanut milk. Furthermore, by unfolding the protein structure, the solubility, surface hydrophobicity and emulsifying properties of the protein were improved, laying the groundwork for subsequent binding and further improvement of stability.

[0041] Step 6: Add 0.16% by mass of ι-carrageenan to the homogenized liquid and shear at high speed for 1 minute using a rotation speed of 6000 r / min.

[0042] Depend on Figure 4 As shown in section A, the zeta potential of peanut milk reaches its maximum value of -41.07 mV (p<0.05) when 0.16% carrageenan is added. Figure 4 As shown in Figures B and C, the peanut milk particle size reaches a minimum of 2.74 μm when 0.16% carrageenan is added. Figure 4 As shown in Figure D, the precipitation was at least 5.15% when 0.16% was added, which was significantly reduced by 6.14% compared to no precipitation (p<0.05). ι-carrageenan molecules have a helical structure at room temperature. This conformation strengthens the electrostatic interaction between peanut protein and carrageenan molecules in peanut milk. As the concentration of ι-carrageenan increases, the electrostatic repulsion between protein and carrageenan increases, increasing the negative charge of the peanut milk. When the carrageenan concentration exceeds 0.16%, more carrageenan molecules adsorb onto peanut protein, causing peanut milk droplets to aggregate and improving the dispersion stability of the peanut milk.

[0043] Depend on Figure 5 As shown in Figure A, after 7 days of storage, the negative charge of peanut milk with different ι-carrageenan concentrations decreased by 6.80 mV, 5.46 mV, 8.54 mV, 7.7 mV, and 11.97 mV, respectively, with peanut milk at an ι-carrageenan concentration of 0.32% carrying the least negative charge. Figure 5 As shown in B, peanut milk with a 0.16% ι-carrageenan concentration had the smallest particle size during storage. This indicates that 0.16% ι-carrageenan has a significant impact on the storage stability of peanut milk (p<0.05), and the peanut milk system gradually tends to stabilize with increasing storage time.

[0044] 0.16% ι-carrageenan forms more hydrogen bonds with amino acid residues in the oil, increasing the stability of the oil. The hydrogen bonding and hydrophobic interactions within the oil also continuously increase. ι-carrageenan effectively prevents oil droplet aggregation and inhibits droplet flocculation and stratification by increasing the electronegativity of the droplet surface. In summary, ι-carrageenan forms a dense adsorption layer on the oil surface by enhancing electrostatic and hydrogen bonding interactions. It stabilizes droplets and prevents aggregation through charge repulsion, and further increases the stability of the oil interfacial film structure through hydrogen bonding.

[0045] The strength of electrostatic interactions increased continuously with increasing addition amount, reaching its maximum at 0.16% protein (268.25 μg / mL). The hydroxyl groups of ι-carrageenan formed more hydrogen bonds with peanut protein. Due to the increase in free sulfhydryl groups in the protein, the electrostatic repulsion of carrageenan inhibited hydrophobic aggregation between proteins, resulting in a decrease in hydrophobic interactions at 0.16% ι-carrageenan concentration. In summary, the main interactions between high-oleic peanut protein and ι-carrageenan are electrostatic and hydrogen bonding interactions. Simultaneously, the electrostatic repulsion effectively inhibits hydrophobic aggregation between proteins, significantly increasing the stability of the protein-polysaccharide emulsion.

[0046] In this embodiment, the optimal ι-carrageenan concentration of 0.16% was selected from the range of 0.16% to 0.32%. By adding 0.16% ι-carrageenan, it binds to the surface charge of the oil body and combines with the unfolded protein structure through electrostatic interaction. Through steric hindrance and electrostatic repulsion, a stable and dense three-dimensional network is formed with the oil body as the intersection and the protein and ι-carrageenan as the lines, thereby improving the dispersion stability and storage stability of high oleic acid peanut milk.

[0047] Among them, ι-carrageenan is a polysaccharide. Based on the Maillard reaction and glycosylation principle, this invention can also use sugars with different structures such as pentose (D-ribose), ketose (D-fructose), aldose (mannose), disaccharide (maltose), oligosaccharide (galactooligosaccharide), and polysaccharide (inulin).

[0048] Protein glycosylation refers to the non-enzymatic Maillard reaction between free amino groups in a protein molecule and the carbonyl group of a reducing sugar, which covalently links the sugar to the protein surface. This modification can alter the spatial conformation and surface properties of proteins, thereby improving their functional properties such as solubility, emulsification, thermal stability, and antioxidant activity.

[0049] The effectiveness of glycosylation is influenced by protein structure, sugar type, and reaction conditions, with the structure and molecular weight of the sugar substrate being key factors. Monosaccharides (especially ribose) have high reactivity and are commonly used in protein glycosylation, exhibiting high grafting rates and significantly expanding protein structures, thereby greatly improving water solubility, foaming ability, emulsifying activity, and antioxidant properties. Polysaccharides (especially inulin) have strong steric hindrance, significantly improving emulsifying stability, foam stability, and pH / heat / salt / storage stability.

[0050] Step 7: Add 0.2% mogroside to the sheared liquid and shear at a high speed of 6000 r / min for 1 min.

[0051] This invention adds 0.1% to 0.2% mogroside, which has the advantages of being naturally zero-calorie and not raising blood sugar. After its addition, it balances the taste and health benefits of high-oleic peanut milk.

[0052] Step 8: Finally, a highly stable high-oleic peanut milk is obtained.

[0053] Color and whiteness are key indicators for evaluating the sensory quality of peanut milk. To investigate the effect of mogroside addition on the color of peanut milk and to screen the optimal addition ratio, three addition amounts of 0.1%, 0.15%, and 0.2% were set. Two commercially available peanut milk products were used as controls, and a systematic evaluation was conducted through color difference and whiteness value.

[0054] A comparison of the whiteness of different peanut milk products shows that as the amount of mogroside added increases, the L* (brightness value) of the peanut milk decreases from 77.85 to 60.07; the a* (red-green value) changes from -3.73 to -6.18; the b* (yellow-blue value) increases from 5.80 to 6.02; and the WH value decreases from 76.80 to 59.14. In terms of color quality, the peanut milk product with 0.2% mogroside added exhibits a pale yellow color, which may be related to the pale yellow nature of the mogroside powder itself, and is also similar to the color of commercially available high-quality peanut milk. Meanwhile, commercially available peanut milk 1 (b* value 7.03) and commercially available peanut milk 2 (b* value 9.48) also exhibit a typical yellowish color. Although the a* value of 0.2% mogroside is slightly greenish (-6.18), it works synergistically with an appropriate yellowness value to create a unique color balance, effectively preventing the peanut milk from appearing too white or too yellow. Compared to two commercially available peanut milks, the L* value of 0.2% mogroside (60.07) is lower than that of commercially available peanut milks (66.03, 66.38), but it exhibits a thicker appearance. Overall, the high-oleic peanut milk product with 0.2% mogroside achieves the optimal balance of brightness, yellowness, and greenness.

[0055] The color, aroma, taste, and texture of peanut milk are important indicators for sensory evaluation. Adding appropriate amounts of mogrosides can impart harmonious sensory qualities and good acceptability to the product. Figure 6 It can be seen that, under the condition of a fixed basic formula for peanut milk products, the 0.2% mogroside peanut milk has the highest sensory evaluation (91.15), which is superior to two commercially available peanut milks (84.31 and 82.08). Furthermore, it exhibits a uniform milky white color (27.77), a rich aroma (17.85), a smooth and delicate texture with moderate sweetness (27.85), and a uniform and stable texture without sedimentation (18.77), achieving an optimal balance across all four indicators. Conversely, other peanut milks exhibit problems such as insufficient sweetness, inadequate aroma, and a thinner texture. Therefore, 0.2% mogroside can enable high-oleic peanut milk products to achieve the best sensory quality.

[0056] The physicochemical indicators of different peanut milk products were tested. A comparison of these indicators shows that all peanut milk products met the requirements of the industry standard QB / T 2439-1997 "Plant Protein Beverages". Specifically, the peanut milk product with added 0.2% mogroside had a fat content of 3.14%, a protein content of 2.13%, and a solids content of 28.32%. These three indicators were higher than other peanut milk samples and significantly better than the industry standard values ​​(fat ≥1.0%, protein ≥0.8%, solids ≥8.0%). The pH of all peanut milk products (7.14~7.30) was within the national standard's allowable range of 6.0~8.0. In summary, the high-oleic peanut milk product with added 0.2% mogroside exhibits the best physicochemical quality while ensuring compliance with standards.

[0057] pH is also a significant influencing factor in peanut milk stability. As pH increases, the proportion of oily proteins significantly increases, while the content of bound water and non-flowing water in the emulsion decreases, and the content of free water and isoelectric point increase. Particle size, viscosity, viscoelasticity, and shear stress also decrease. When pH increases from 4.8 to 5.0, the isoelectric point gradually increases; at pH 6.5, the emulsion particle size, viscosity, viscoelasticity, and shear stress are relatively high, making it suitable for 3D printed foods; when pH increases from 9.0 to 11.0, the release of total free fatty acids (FFA) is more gradual, making it more suitable for loading functional nutrients; at pH 11.0, the emulsion particle size is the smallest. Therefore, overall, a neutral pH value is more conducive to the stability of peanut milk.

[0058] Particle size can reflect the stability of an emulsion system. Generally, the smaller the average particle size, the more stable the emulsion. Zeta potential reflects the charged state of peanut emulsion droplets and is another key parameter for evaluating emulsion stability. Figure 7 As shown in Figure A, the particle size of peanut milk gradually decreased. The peanut milk with 0.2% mogroside added had the smallest particle size (3.21 μm), which was significantly better than the peanut milk with 0.1~0.15% added (3.32 μm, 3.26 μm) and two commercially available peanut milks (17.61 μm, 18.57 μm) (p<0.05). Figure 7 As shown in Figure B, the peanut product with the highest negative charge in the emulsion potential (36.53 mV) was achieved with 0.2% zeta potential, higher than that with 0.1%~0.15% zeta potential (35.53 mV, 35.67 mV) and two commercially available peanut milk products (34.27 mV, 28.13 mV). When the zeta potential carries a charge greater than 30 mV, it exhibits strong electrostatic repulsion, effectively inhibiting particle aggregation and resulting in a more stable emulsion system. Figure 7The results showed that after adding 0.1-0.2% mogroside, the particle size distribution of the peanut milk exhibited a uniform unimodal distribution, while the particle size distribution of the two commercially available peanut milk products showed a bimodal distribution. These results indicate that the peanut milk with added mogroside has better uniformity and stability. The large particle size of commercially available peanut milk may be due to the addition of various thickeners, emulsifiers, and other food additives, leading to the formation of large particles. Furthermore, high-temperature sterilization of the peanut milk causes some proteins to denature and aggregate, resulting in a bimodal particle size distribution. Figure 7 The results showed that with increasing amounts of mogroside, the centrifugal sedimentation rate of peanut milk exhibited a continuous downward trend, decreasing from 20.23% to 17.71%, reaching its lowest point at 0.2%. This may be related to its smaller particle size and larger negative potential charge. Commercially available peanut milk had even lower sedimentation rates (6.86% and 9.33%), possibly due to the addition of thickeners that increased the system's viscosity. In summary, peanut milk products containing 0.2% mogroside maintained a smaller particle size while exhibiting more uniform droplet distribution, which is beneficial for improving the stability of high-oleic peanut milk products.

[0059] Storage stability is a key indicator for evaluating the ability of peanut milk to maintain its quality during storage. Changes in potential, particle size, and emulsion appearance can directly reflect the physical stability of peanut milk. For example... Figure 8 As shown in Figure A, the electrostatic potential of different peanut milk products decreased significantly with prolonged storage time (p<0.05). After 7 days of storage, when 0.1-0.2% mogroside was added, the zeta potential of the peanut milk products decreased from -35.53 mV to -28.87 mV (0.1%), a decrease of 18.7%; from -35.67 mV to -30.00 mV (0.15%), a decrease of 15.9%; and from -36.53 mV to -32.00 mV (0.2%), a decrease of 12.4%. The potential of commercially available peanut milk 1 decreased from -34.27 mV to -33.30 mV, a decrease of only 2.8%; the potential of commercially available peanut milk 2 decreased from -28.13 mV to -27.93 mV, remaining basically stable but with a smaller amount of negative charge, indicating a weakening of electrostatic repulsion between particles. like Figure 8As shown in Figure B, with prolonged storage time, the particle size D4,3 of peanut milk products with different mogroside additions (0.1~0.2%) and two commercially available peanut milk products showed an increasing trend and significant differences (p<0.05). After 7 days of storage, when mogroside was added at 0.1%, the particle size D4,3 of the peanut milk product increased from 3.32 μm to 6.22 μm (7 days); when added at 0.15%, it increased from 3.26 μm to 5.80 μm; and when added at 0.2%, it increased from 3.21 μm to 5.63 μm. The particle size D4,3 of commercially available peanut milk 1 increased from 17.61 μm to 19.08 μm, and that of commercially available peanut milk 2 increased from 18.57 μm to 19.28 μm. The results showed that peanut milk products containing 0.2% mogroside exhibited good storage stability, characterized by a small decrease in negative charge and a small increase in particle size. Figure 8 As shown in the C-shaped appearance diagram, after 7 days of storage, the peanut milk product with 0.2% mogroside showed the least stratification, most closely resembling the appearance of the two commercially available peanut milk products. This indicates that the addition of 0.2% mogroside effectively alleviates droplet aggregation and reduces the negative charge, possibly because the addition of mogroside enhances the system's viscosity and electrostatic repulsion, inhibiting droplet aggregation during storage. Therefore, the peanut milk product with 0.2% mogroside exhibits the best storage stability. Example

[0060] The difference from Example 1 is that step 1 involves weighing 100 parts of high-oleic peanut kernels, 25 parts of pumpkin seed oil, and 25 parts of glycosylated pea protein isolate, and baking them at 140℃~160℃ for 20 minutes.

[0061] Pumpkin seeds are a byproduct of pumpkin cultivation, with an annual yield of approximately 700,000 tons in my country. Pumpkin seeds are high in oil, accounting for about 35% to 64.4% of their dry weight. Pumpkin seed oil is an edible vegetable oil containing 16 fatty acids, including linoleic acid, oleic acid, palmitic acid, and stearic acid. Linoleic acid, a polyunsaturated fatty acid, has the highest content in pumpkin seed oil at 42.49%, followed by oleic acid, a monounsaturated fatty acid, at 33.69%. Pumpkin seeds contain about 6.4% protein, containing 16 amino acids. The absorption rate of pumpkin seed protein in the human body can reach 88% to 97%, with a physiological value of 73% to 86%. In addition, pumpkin seeds are rich in minerals such as calcium, magnesium, zinc, iron, potassium, and phosphorus.

[0062] This embodiment uses pumpkin seed kernels as raw material to study the basic composition, protein composition, dispersion stability, storage stability, thermal stability, freeze-thaw stability, oxidative stability, textural properties, and rheological properties of high internal phase pumpkin seed oil emulsion (HIPEs-PSOB) prepared under different centrifugal forces and extraction pH conditions. It also studies the fatty acid composition and moisture distribution of HIPEs-PSOB under different extraction pH conditions, providing theoretical and experimental basis for the preparation of highly stable high oleic acid peanut emulsion and the application of pumpkin seeds and their oil bodies.

[0063] Effect of different centrifugal forces on HIPEs-PSOB: Under pH 6.5 conditions, oil emulsions with 72% oil phase and HIPEs-PSOBs with different oil phases (78%, 80%, 83%, 90%) were prepared by adjusting the centrifugal force (1000×g, 2800×g, 14500×g, 20000×g, 31000×g).

[0064] As the centrifugal force increased from 1000×g to 31000×g, the oil phase content of the obtained samples increased from 72% to 90%. Sunflower seed OBs extracted at pH 9.0 yielded high internal phase emulsion gels (HIPEs-gel) with an oil phase content of 76%–91%, while HIPEs-gels could not be formed at extraction pH 5.5. Due to differences in oil source and extraction method, HIPE-PSOB with an oil phase volume fraction of 90% was successfully prepared at pH 6.5. The protein composition of HIPE-PSOBs was the same under different centrifugal forces, containing oil body proteins (14.5 kDa, 21.2%) and exogenous proteins (14.3%, 22 kDa; 7.1%, 27 kDa; 31.5%, 33 kDa; 25.9%, 45 kDa), with an isoelectric point of pH 5.25 for all samples. Due to varying Laplace pressures, HIPEs-PSOB droplets exhibit polygonal shapes when the oil phase volume fraction is above 80%. Under lower Laplace pressures, monodisperse systems containing larger droplets can form polygonal droplets with lower interfacial tension. Conversely, under high Laplace pressures, monodisperse systems containing smaller droplets can maintain a spherical shape. All HIPEs-PSOBs demonstrate good storage stability, indicating that most droplets in all HIPEs-PSOBs possess significant interfacial deformability. Greater interfacial deformability more effectively protects droplets from coalescence. With minimal water content and fewer ice crystals formed, which have almost no impact on droplet interfacial properties, 90%-HIPE-PSOB exhibits better freeze-thaw stability.

[0065] The physicochemical properties of HIPEs-PSOBs with different oil phase volume fractions differed. HIPEs-PSOBs with 78%–90% oil phase were prepared under pH 6.5 conditions with increasing centrifugal force. The water content of HIPEs-PSOBs decreased with increasing oil phase concentration. All HIPEs-PSOBs contained 14.5 kDa oil body protein and exogenous proteins of 22 kDa, 27 kDa, 33 kDa, and 45–60 kDa. The isoelectric point of HIPEs-PSOBs was pH 5.25, and the D4,3 ratio increased from 4.25 μm to 7.34 μm with increasing oil phase volume fraction. Droplets of 72%-PSOB and 78%-HIPE-PSOBs were spherical, while those with an oil phase concentration above 83% were polygonal. With the increase of oil phase volume fraction, thermal stability decreases, while apparent viscosity, viscoelasticity, yield stress, freeze-thaw stability, and oxidation stability increase.

[0066] Effect of different extraction pH conditions on HIPEs-PSOB: HIPEs-PSOB with different protein compositions were prepared by adjusting the extraction pH (pH 6.5, pH 9.0, pH 11.0).

[0067] The oil phase of pH 6.5 HIPEs-PSOB was 83% under centrifugal force of 20000×g, while the oil phase of pH 9.0 and pH 11.0 HIPEs-PSOB reached 83% under 5000×g. Therefore, as the extraction pH increases, HIPEs-PSOB with a high oil phase can be obtained under lower centrifugal force. pH 6.5 HIPE-PSOB contains 14.5 kDa of oil body protein and 22 kDa, 27 kDa, 33 kDa, and 45~60 kDa of exogenous protein. pH 9.0 HIPE-PSOB contains 22 kDa, 27 kDa, and 33 kDa of exogenous protein and 14.5 kDa of oil body protein, while pH 11.0 HIPEs-PSOB contains almost only 14.5 kDa of oil body protein. Because the exogenous protein is not tightly bound to the oil body, it can be removed by washing with alkaline solution. The structure of oil body proteins consists of a hydrophobic center embedded in the TAG matrix and its exposed N- and C-termini. Exogenous proteins decrease with increasing extraction pH, while oil body proteins are unaffected by alkaline pH. Free water is the predominant state of water in HIPEs-PSOBs; the transverse relaxation time T2 gradually increases with increasing extraction pH, indicating good water mobility and a high degree of freedom.

[0068] Due to the adsorption of more exogenous proteins on the surface of HIPEs-PSOB under low extraction pH conditions, the isoelectric point of HIPEs-OB shifts to the right as the extraction pH increases. As the extraction pH increases, it becomes closer to the isoelectric point of the oil body, reducing electrostatic repulsion and making aggregation more likely; the D4,3 value decreases from 6.21 μm to 2.57 μm.

[0069] All samples exhibited polygonal morphologies. The textural and rheological properties of HIPEs-PSOBs obtained at different extraction pH values ​​varied. However, due to the high centrifugal force applied to pH 6.5-HIPE-PSOB, water that was not tightly bound to the droplet surface could be ejected, allowing the droplets to be more tightly compressed together, resulting in a stronger solid-like structure. The pH 6.5-HIPE-PSOB surface adsorbed more exogenous proteins, enhancing the gel network of HIPE-PSOB. Simultaneously, this increased the thickness of the oil-body interfacial film, increasing the force required for droplet deformation. Therefore, pH 6.5-HIPE-PSOB exhibited the highest hardness, adhesion, elasticity, adhesiveness, apparent viscosity, viscoelasticity, and yield stress.

[0070] The physicochemical properties of HIPEs-PSOBs with different protein contents and compositions vary. Exogenous protein content decreases with increasing extraction pH. Free water constitutes the majority of the water in the system, exceeding 97%, while the proportion of all non-flowing water is less than 2%, and the proportion of bound water is less than 1%. All HIPEs-PSOBs exhibit polygonal microstructures. HIPEs-PSOBs contain 10 fatty acids. With increasing extraction pH, particle size, bound water proportion, non-flowing water proportion, apparent viscosity, viscoelasticity, yield stress, and freeze-thaw stability decrease, while isoelectric point, free water proportion, thermal stability, and oxidative stability increase.

[0071] Therefore, the high-oleic peanut milk produced contains pumpkin seed oil, which helps to improve the thermal stability, freeze-thaw stability and oxidative stability of the high-oleic peanut milk.

[0072] In this embodiment, pea protein isolate (PPI) undergoes a glycosylation reaction with the polysaccharide carrageenan in step 6, so the high oleic peanut milk produced also contains glycosylated pea protein isolate.

[0073] PPIs are mainly composed of two major protein classes: globulins and albumins. Globulins are the most abundant component, accounting for approximately 65%-80% of the total protein content, followed by albumins, which account for 10% to 20%. Globulins can be further classified into legumin (11S), vicilin (7S), and convicilin based on their sedimentation coefficients. Structurally, 11S globulins have a hexamer structure, with acidic and basic subunits linked by disulfide bonds to form a stable complex structure, exhibiting high thermal stability and structural compactness. 7S globulins, on the other hand, mainly exist in a trimer form, with a relatively loose molecular structure and more exposed hydrophobic and polar groups on the surface, thus exhibiting superior functional properties such as solubility, emulsification, and interfacial activity. In addition, PPIs also contain small amounts of minor protein components such as enzymes and protease inhibitors. The differences in molecular structure, amino acid composition, and spatial conformation of these different types of proteins give PPIs a variety of physicochemical properties and functional characteristics, such as good emulsifying, gelling, and foaming properties.

[0074] To improve the structural and functional properties of plant proteins, glycosylation is carried out through the Maillard reaction, a non-enzymatic chemical reaction between amino groups and reducing sugars. Glycosylated products typically exhibit better dispersibility, emulsification, and stability, or better solubility and emulsification performance than unmodified PPIs. Furthermore, emulsion particles stabilized by glycosylated products have smaller, more uniform, and more stable particle sizes.

[0075] (1) Effects of sugar structure on the glycosylation behavior and functional properties of pea protein isolate Using PPI as a raw material, ribose, fructose, mannose, maltose, galactooligosaccharides (Oli), and inulin were selected for glycosylation modification to prepare PPI-glycoconjugates. The physicochemical properties, including degree of glycosylation, browning degree, particle size, zeta potential, intrinsic fluorescence, secondary structure, and surface hydrophobicity, were analyzed. Functional properties, such as solubility, emulsifying properties, foaming properties, and antioxidant properties, were determined to explore the influence of sugar structure on the glycosylation behavior, structural changes, and functional improvement of pea protein isolate.

[0076] Degree of glycosylation (DG) is commonly used to characterize the extent to which protein amino groups and reducing sugar carbonyl groups covalently bond during the Maillard reaction. Compared to polysaccharide-modified systems, monosaccharide-modified PPIs exhibit significantly higher DG values. This is related to the larger number of active carbonyl groups per molecule in monosaccharides, coupled with their smaller molecular weight, lower steric hindrance, and faster diffusion rate, which facilitates their reaction with protein amino groups and improves grafting efficiency. Specifically, pentoses are more reactive than hexoses; ketoses react more rapidly than aldoses; and branched sugars are generally more reactive than linear sugars.

[0077] Under the conditions of this embodiment, the Maillard glycosylation reaction was relatively mild overall, and the accumulation of AGEs was controlled to a certain extent. Covalent linkages such as COC and C-OH were formed between PPI and sugars. The electron cloud density of nitrogen atoms decreased, while the electron attraction environment around oxygen atoms was enhanced. Glycosylation disrupted the original ordered spatial structure of the protein, making its conformation tend to be loose and disordered. The β-turn structure facilitates the bending and extension of the polypeptide backbone and participates in the stability of protein conformation to a certain extent. Glycosylation changed the conformation or aggregation state of the protein, exposing aromatic amino acid residues to a more hydrophilic environment. Grafting of larger molecular weight sugars may produce a strong steric hindrance effect on the protein surface, thereby limiting the further unfolding of the protein to a certain extent. The content of hydrophilic amino acids was higher than that of hydrophobic amino acids, resulting in changes in the charge distribution on the protein surface and enhancing the electrostatic repulsion between protein molecules, thereby helping to inhibit protein aggregation. The absolute value of the Zeta potential of the polysaccharide-modified sample was higher than that of the monosaccharide-modified sample. The polysaccharide chain introduced more negatively charged carboxyl or hydroxyl groups, and free -SH The increased content helps enhance the reactivity between amino acid residues and reducing sugar hydroxyl groups in protein molecules, thereby improving DG and having a positive impact on functional properties such as protein foaming stability.

[0078] Compared to PPIs, all glycosylated conjugates exhibited improved solubility. Higher temperatures exposed some charged groups and polar amino acid residues embedded within the protein to the molecular surface, thereby enhancing the interaction between the protein and water molecules and increasing solubility. Glycosylation modification further significantly improved the solubility of PPIs, with effects markedly superior to both PPIs and PCs. Grafting sugar molecules introduced numerous hydrophilic glycan chains onto the protein surface, enhancing hydrogen bonding and hydrophilic interactions between the protein and water molecules. Furthermore, the presence of glycan chains weakened hydrophobic interactions between protein molecules and inhibited protein aggregation through steric hindrance, thus helping to maintain the dispersed state of protein molecules. Different sugar types had varying effects on solubility. Monosaccharide-modified samples showed slightly higher solubility than oligosaccharide and polysaccharide-modified samples; monosaccharides had a greater number of grafts onto the protein surface, thus more effectively enhancing the hydrophilicity of the protein surface.

[0079] The emulsifying properties of proteins are typically characterized by emulsifying activity and emulsifying stability. Glycosylation increases protein solubility and reduces particle size, enabling more rapid migration and adsorption at the oil-water interface during homogenization, resulting in smaller oil droplets. Monosaccharide-modified samples exhibit higher emulsifying activity than polysaccharide-modified samples. Monosaccharide-modified proteins possess higher solubility and smaller particle size, thus enhancing their ability to rapidly adsorb to the oil-water interface during homogenization. Oligosaccharide and polysaccharide-modified samples show less improvement in emulsifying activity (EAI) than monosaccharide-modified samples. The longer sugar chains form a thicker and more viscoelastic interfacial layer on the oil droplet surface, resulting in a stronger steric hindrance effect. PPI-glycoconjugates exhibit higher apparent viscosity and storage modulus, indicating the formation of a denser and more elastic network structure, which helps restrict oil droplet movement and thus improves emulsifying stability.

[0080] The foaming properties of proteins mainly depend on their adsorption capacity at the air-water interface and their ability to form a stable interfacial film. PPIs contribute approximately 62% to foaming capacity and 72% to foam stability, with glycosylation significantly improving both. Glycosylation enhances the interfacial adsorption and rearrangement capabilities of protein molecules, allowing for faster unfolding and rearrangement at the air-water interface, thus promoting foam formation and enhancing interfacial film stability. Different sugar types have significantly different effects on foaming properties. P-Rib, P-Fru, and P-Man exhibit higher initial foaming capacity, while P-Oli and P-Inu demonstrate superior foam stability. This difference is mainly related to the regulatory effects of different sugars on protein conformation, aggregation state, and surface properties. Monosaccharide-modified proteins have smaller particle sizes and higher solubility, which facilitates their rapid diffusion and adsorption at the air-water interface, thereby promoting bubble formation. Among them, P-Rib has the highest FC value (130%), which is closely related to its highest degree of glycosylation (DG 61%) and high solubility (66%). These properties enable it to adsorb onto the interface more rapidly, thus achieving higher foaming ability. In addition, the low viscosity of the monosaccharide system reduces diffusion resistance, which is also conducive to foam formation.

[0081] In contrast, P-Inu exhibited the highest foam stability (88%). Its higher viscosity and storage modulus formed a weak gel network structure, which provided mechanical support for the bubbles and restricted liquid flow, thereby delaying foam collapse and improving long-term foam stability. Furthermore, the two-phase contact angle measurements further supported the above analysis. Glycosylation reduced the contact angle of PPI, indicating enhanced hydrophilicity and facilitating rapid diffusion to the air-water interface, consistent with the improved foaming ability of monosaccharide-modified samples. Oligosaccharide and polysaccharide-modified samples showed moderately higher contact angles, indicating that their interfacial films were more elastic and cohesive, thus contributing to improved foam stability.

[0082] The results showed that the degree of glycosylation and browning in the monosaccharide system was generally higher than that in the oligosaccharide and polysaccharide systems, with ribose exhibiting the highest reactivity and inulin the lowest. Glycosylation significantly altered the molecular structure of PPIs, transforming them from relatively ordered to loosely disordered, manifested as reduced particle size, increased absolute value of Zeta potential, decreased surface hydrophobicity, and increased exposure of free thiol groups. It also significantly improved solubility, emulsifying properties, foaming properties, and antioxidant activity. Overall, monosaccharides were more conducive to increasing the degree of glycosylation, while long-chain sugars were more advantageous in enhancing steric hindrance and interfacial stability.

[0083] (2) Preparation and environmental stability study of glycosylated protein emulsions Emulsions were prepared using different PPI-glycan conjugates as emulsifiers. The effects of different PPI-glycan conjugates on emulsion-forming ability were compared, and the appearance, particle size distribution, microstructure, and rheological properties of the emulsions were analyzed. Based on this, the effects of environmental factors such as storage, pH, temperature, and salt ions on the emulsion properties were further investigated.

[0084] With prolonged storage, the stability of all emulsion systems decreased. At 0 days of storage, all freshly prepared emulsions exhibited a uniform milky-white appearance with no obvious stratification. After 7 days, emulsions stabilized by PPI and PC began to show slight stratification. At 14 days of storage, the emulsion stabilized by monosaccharide glycosylated proteins showed more obvious oil-water phase separation. By 28 days of storage, the oligosaccharide glycosylated system also showed visible stratification. In contrast, the polysaccharide-stabilized emulsion did not show significant oil-water separation throughout the entire storage period, maintaining a relatively uniform milky-white appearance. This indicates that glycosylation modification can delay the emulsion instability process, with polysaccharide coupling modification showing the most significant effect, exhibiting strong resistance to milk fat buoyancy and phase separation.

[0085] The emulsions stabilized by glycosylated proteins showed minimal particle size change during 28 days of storage, with the polysaccharide-modified system exhibiting the least particle size fluctuation and demonstrating higher structural stability. Grafting of sugar molecules enhanced the steric hindrance at the oil droplet interface and weakened the hydrophobic interactions between oil droplets, thereby effectively inhibiting oil droplet aggregation.

[0086] As storage time increases, the interfacial composition or structure changes, leading to a weakening of the electrostatic repulsion between oil droplets. Consequently, the absolute values ​​of the Zeta potential of oil droplets in all emulsion systems show a decreasing trend. The polysaccharide-modified system maintains a high absolute value of the Zeta potential throughout the storage period, indicating that glycosylation helps maintain strong interfacial electrostatic stability, thereby improving the storage stability of the emulsion. Emulsions stabilized by glycosylated proteins maintain a relatively small and uniformly distributed oil droplet structure throughout storage, with the polysaccharide-modified system exhibiting the greatest stability.

[0087] Glycosylated PPI-stabilized emulsions, especially polysaccharide-modified systems, showed significantly reduced stratification under the aforementioned conditions. After sugar molecules were covalently grafted onto the protein surface, the surface hydrophobicity of the protein was reduced, and steric hindrance was enhanced, thereby inhibiting the aggregation and coalescence of oil droplets. Furthermore, some degree of water precipitation was observed in all systems, possibly related to the use of simple stirring rather than high-pressure homogenization during emulsion preparation, resulting in insufficient uniform oil droplet dispersion. Therefore, a high-pressure homogenizer was used for homogenization in the preparation of high-oleic peanut milk to promote uniform liquid dispersion and mixing.

[0088] The glycosylated protein-stabilized emulsions exhibited smaller particle sizes than the PPI system across the entire pH range, with the polysaccharide-modified system showing the smallest particle size and the P-Inu system demonstrating the best stability. The conjugates formed a thicker interfacial layer with long-range repulsion at the oil droplet interface, enhancing the steric hindrance effect and effectively inhibiting oil droplet aggregation. Notably, although the particle size reached its maximum at pH 5, no obvious stratification was observed; the oil droplets formed a relatively compact aggregate network structure near the isoelectric point, thus enhancing the system's resistance to gravitational separation to some extent. The glycosylated system maintained a high absolute potential value across the entire pH range, especially the polysaccharide-modified system, indicating that glycosylation helps maintain a high interfacial charge density, and the grafting of sugar molecules alters the conformation of protein molecules at the interface and the exposure of charged groups. The glycosylated protein-stabilized emulsions maintained a relatively small and uniformly distributed oil droplet structure across the entire pH range, with the polysaccharide-modified system exhibiting the greatest stability.

[0089] Glycosylated PPIs significantly reduced the stratification of emulsions, with oligosaccharide and polysaccharide grafting systems exhibiting superior stability. Glycosylation significantly improved the emulsion's resistance to thermal instability; the grafting of sugar molecules enhanced the steric hindrance at the oil droplet interface and weakened the hydrophobic interactions between protein molecules, thereby effectively inhibiting oil droplet aggregation during heating.

[0090] The PPI-stabilized emulsions exhibited minimal particle size change after heat treatment, demonstrating good resistance to thermal aggregation. After heating, the particle size of the oligosaccharide and polysaccharide-modified systems was significantly smaller than that of the monosaccharide-modified systems, with the P-Inu emulsion exhibiting the strongest thermal stability. The increased molecular weight of the sugar chains helps enhance interfacial steric hindrance, effectively reducing the interaction and aggregation tendency between oil droplets during heat treatment. The glycosylated system maintained a high absolute potential value under various temperature conditions. This indicates that glycosylation helps maintain a high interfacial charge density and stronger electrostatic repulsion, thereby improving the thermal stability of the emulsion.

[0091] Glycosylated PPI-stabilized emulsions exhibited good stability in the presence of salt, but some stratification was still observed, which is related to the relatively large oil droplet size in the system. The improvement in salt stability due to glycosylation stems from the additional steric hindrance provided by the sugar chains at the interface, thus inhibiting oil droplet aggregation to some extent. The particle size variation of glycosylated PPI-stabilized emulsions was small across the entire NaCl concentration range, demonstrating good resistance to salt aggregation. Sugar chain branching weakened the hydrophobic interactions between oil droplets, thus maintaining good dispersion even in the presence of salt. Glycosylated PPI-stabilized emulsions maintained a high absolute potential value under the same salt concentration, indicating that glycosylation mitigated the weakening effect of increased ionic strength on interfacial charge to some extent, thereby enhancing electrostatic repulsion between oil droplets. This effect was particularly pronounced in the polysaccharide-modified system, possibly due to the stronger steric hindrance provided by the high molecular weight sugar chains on the oil droplet surface, thereby improving the salt ion stability of the emulsion.

[0092] The results showed that glycosylated PPI-stabilized emulsions exhibited better environmental stability under storage, pH, temperature, and salt ion conditions. Compared with unmodified PPI, glycosylated PPI had smaller particle size variation, higher absolute potential value, and more uniform microstructure, indicating that the introduction of sugar chains helps enhance interfacial film stability and inhibit droplet aggregation, thereby improving the emulsion system's tolerance to external environmental stresses. Among them, oligosaccharide and polysaccharide modified systems performed better under complex environmental conditions, indicating that sugar chain length and structural complexity are important factors regulating the stability of PPI emulsions, and long-chain sugars have a more significant advantage in enhancing steric hindrance and maintaining interfacial film integrity.

[0093] Therefore, this embodiment achieves a strong combination of natural oil and glycosylated protein by adding pumpkin seed oil and glycosylated pea protein isolate to high oleic peanut kernels, and superimposing the effects of baking temperature, ultrasonic power, carrageenan concentration, etc., thereby improving thermal stability, freeze-thaw stability, oxidative stability and salt ion stability, and producing more stable high oleic peanut milk.

[0094] In summary, this invention reduces the potential of oil and protein, decreases the particle size of oil and protein, expands the protein structure, and improves protein solubility, surface hydrophobicity, and emulsifying properties by selecting specific baking temperatures, ultrasonic power, and carrageenan concentration ranges. This allows the oil in peanut milk to bind with each other through sugars, and the protein to bind to sugars, achieving a stable combination and synergistic effect among oil, sugars, and proteins. Consequently, it enhances dispersion stability, thermal stability, and storage stability, comprehensively improving the stability of high-oleic peanut milk.

Claims

1. A process for the preparation of high stable high oleic peanut milk based on synergistic effect of natural oil body and glycosylated protein characterized by, Includes the following steps: Step 1: Weigh out 100 portions of high-oleic peanut kernels and bake at 140℃~160℃ for 20 minutes; Step 2: Remove the red skin from the peanuts and soak them in 4℃ deionized water for 12 hours; Step 3: Add deionized water to the soaked peanuts at a concentration ratio of 1:8, mix and blend into a paste; Step 4: The pulped liquid is filtered through four layers of degreased gauze and homogenized using a high-pressure homogenizer at 25℃ and 60 MPa. Step 5: The filtered liquid is treated with ultrasonic power of 90W~270W in an ice water bath and homogenized using a high-pressure homogenizer at 25℃ and 60 MPa. Step 6: Add 0.16%~0.32% ι-carrageenan by mass to the homogenized liquid and shear at high speed at 6000 r / min for 1 min; Step 7: Add 0.1%~0.2% mogroside to the sheared liquid and shear at a high speed of 6000 r / min for 1 min; Step 8: Finally, a highly stable high-oleic peanut milk is obtained.

2. A process for the preparation of high stable high oleic groundnut milk based on synergistic effect of natural oil body and glycosylated protein as claimed in claim 1, wherein: In step 1, the baking temperature is 150°C.

3. The method for preparing highly stable high-oleic peanut milk based on the synergistic effect of natural oils and glycosylated proteins according to claim 1, characterized in that: In step 5, the ultrasonic power is 210W.

4. The method for preparing highly stable high-oleic peanut milk based on the synergistic effect of natural oils and glycosylated proteins according to claim 1, characterized in that: In step 6, the mass concentration of ι-carrageenan is 0.16%.

5. The method for preparing highly stable high-oleic peanut milk based on the synergistic effect of natural oils and glycosylated proteins according to claim 1, characterized in that: In step 7, the mass concentration of mogroside is 0.2%.

6. The method for preparing highly stable high-oleic peanut milk based on the synergistic effect of natural oil bodies and glycosylated proteins according to any one of claims 1-5, characterized in that: In step 1, 100 parts of high-oleic peanut kernels, 25 parts of pumpkin seed oil, and 25 parts of glycosylated pea protein isolate are weighed.

Images