A high internal phase water-in-oil emulsion and its use as a fat substitute in mayonnaise

Abstract

The application discloses a high internal phase water-in-oil emulsion and application of the high internal phase water-in-oil emulsion as a fat substitute in salad dressing, and belongs to the technical field of fat substitutes. The preparation of the high internal phase water-in-oil emulsion comprises the following steps: dissolving dioscin and SP in chloroform, and then evaporating the chloroform to obtain DGSP particles; dispersing the prepared DGSP particles in rapeseed oil, and then dispersing a water phase drop by drop into the rapeseed oil to obtain a water-oil mixture, and then performing shearing emulsification to obtain W / O-HIPE. The oil gel-based W / O-HIPE with DGSP particles is used as a fat substitute to prepare a fat-reducing salad dressing, so that the fat-reducing salad dressing can have similar performance to normal salad dressing while reducing fat.

Description

Technical Field

[0001] This invention relates to a high internal phase water-in-oil emulsion and its application as a fat substitute in salad dressing, belonging to the technical field of fat substitutes. Background Technology

[0002] Salad dressing is a common condiment in daily life, an O / W emulsion stabilized by egg yolk lecithin. While salad dressing provides sensory pleasure, it contains approximately 50-60% vegetable oil, making it a high-calorie food. Excessive intake of high-calorie foods can lead to many chronic diseases, such as obesity, diabetes, and hypertension. As consumers become increasingly health-conscious, the development of low-fat salad dressings is receiving more and more attention. Reducing the oil phase volume fraction is the simplest way to reduce fat intake. However, the oil phase plays a crucial role in the appearance, texture, smoothness, mouthfeel, and flavor of salad dressing. Blindly reducing the amount of oil is not advisable. Finding fat substitutes is a very effective approach. Many researchers have developed materials based on protein, dietary fiber, and carbohydrates as fat alternatives. However, it is important to note that protein may trigger allergic reactions in certain populations. Furthermore, the presence of macromolecular fiber, protein, and carbohydrates can also affect the fluidity and dynamic release of flavor, slowing down the flavor intensity of the salad dressing. Therefore, designing a novel fat substitute that does not affect the functional properties of salad dressing is a key focus.

[0003] W / O-HIPE, with a dispersed phase water content of at least 75%, offers the advantage of low calories. Furthermore, the high concentration of droplets in W / O-HIPE, a high-internal-phase water-in-oil emulsion, imparts good viscoelasticity and consistency, resulting in a texture similar to salad dressing. In addition, W / O-HIPE can encapsulate hydrophilic bioactive components for developing functional salad dressings. Recently, Prosapio et al. and You et al. demonstrated the feasibility of using cocoa butter-in-water emulsions to replace cocoa butter in the production of low-calorie chocolate. The cocoa butter content of the chocolate was reduced to 40% and 75%, respectively, while maintaining performance close to full-fat chocolate. However, few studies have applied W / O-HIPE to salad dressings to reduce the oil phase content. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide a high internal phase water-in-oil emulsion and its application as a fat substitute in salad dressing. This invention uses DGSP particle-stabilized oleogel-based W / O-HIPE as a fat substitute to prepare a low-fat salad dressing, which reduces fat content while maintaining properties similar to normal salad dressing.

[0005] To achieve the above objectives, the following technical solution is provided: The purpose of this invention is to provide a method for preparing a high internal phase water-in-oil emulsion, the method comprising the following steps: (1) Dissolve diosgenin and SP in chloroform, then evaporate the chloroform to obtain DGSP particles; (2) Disperse the DGSP particles prepared in step (1) into rapeseed oil, and then disperse the aqueous phase dropwise into rapeseed oil to obtain a water-oil mixture. Then shear emulsify to obtain W / O-HIPE.

[0006] In one embodiment, the mass ratio of diosgenin to SP in step (1) is 1:1.

[0007] In one embodiment, the evaporation temperature in step (1) is 40~50°C.

[0008] In one embodiment, the DGSP particles dispersed in rapeseed oil in step (2) are specifically at a concentration of 100-120 mg / L. o DGSP particles were dispersed in rapeseed oil under heating conditions C.

[0009] In one embodiment, the amount of DGSP particles added in step (2) is 3.0 wt%.

[0010] In one embodiment, the proportion of the aqueous phase in step (2) is 75%.

[0011] In one embodiment, the shearing conditions in step (2) are: 12000 rpm for 3 to 5 minutes.

[0012] The present invention also provides W / O-HIPE prepared by the method described above.

[0013] The present invention also provides the application of the aforementioned W / O-HIPE in food processing.

[0014] This invention also provides a method for preparing a low-fat salad dressing, the method comprising: Mix rapeseed oil, W / O-HIPE, water, egg yolk powder, vinegar, sugar, salt, xanthan gum, and modified starch until smooth to make a low-fat salad dressing.

[0015] In one embodiment, the amount of W / O-HIPE used is 10-50 wt% of rapeseed oil.

[0016] In one embodiment, the ingredients are: 50 parts rapeseed oil, 30 parts water, 7 parts egg yolk powder, 3 parts vinegar, 6.2 parts white sugar, 1 part edible salt, 0.8 parts xanthan gum, and 2 parts deformed starch.

[0017] The present invention also provides a low-fat salad dressing prepared by the method described above.

[0018] Beneficial effects: The oil phase plays a crucial role in maintaining the physical properties of salad dressing. The aim is to reduce the oil phase content of salad dressing without affecting its properties. This invention uses DGSP-stabilized oleoglucon-based W / O-HIPE as a fat substitute to prepare a low-fat salad dressing, reducing fat content while maintaining properties similar to regular salad dressing. The main advantages are as follows: (1) When W / O-HIPE replaces 10-30% of the oil, the appearance of the low-fat salad dressing is not significantly different from that of the normal salad dressing; (2) The reduced-fat salad dressing with a 30% oil phase substitution rate has similar viscoelasticity, oral deformation properties and lubricity to normal salad dressing; (3) Through PCA and CA analysis based on electronic nose sensor signals, the flavor characteristics of the reduced-fat salad dressing with 30% oil phase replacement rate are similar to those of normal salad dressing; (4) The reduced-fat salad dressing with a 30% oil phase substitution rate has similar sensory characteristics to the high-fat salad dressing. Attached Figure Description

[0019] Figure 1 The appearance changes of low-fat salad dressings with an oil phase substitution rate of 10-50% are shown in the diagram. Figure 2 The diagram shows the microstructure changes of low-fat salad dressings with an oil phase substitution rate of 10-50%. Figure 3 A graph showing the rheological property changes of low-fat salad dressings with an oil phase substitution rate of 10-50%; Figure 4 The graph shows the elasticity of the Lissajous curve. Figure 5 This is a Lissajous curve for viscosity. Figure 6 A graph showing the changes in the tribological properties of low-fat salad dressings with an oil phase substitution rate of 10-50%; Figure 7 An image showing electronic nose analysis data for low-fat salad dressings with an oil phase substitution rate of 10-50%; Figure 8 Sensory analysis diagram of a low-fat salad dressing with an oil phase substitution rate of 10-50%. Detailed Implementation

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. The specific embodiments described below further illustrate the present invention.

[0021] The testing method involved in this invention: 1. Tribological property determination The tribological properties of different salad dressing samples were tested using a micro-traction testing machine. A 50.0 g sample of salad dressing was filled into the sample chamber, ensuring the sample completely covered the sample plate. A normal load of 1 N was set to simulate the intraoral forces of oral cavity activity, with a clamping speed of 1-1000 mm¹ / s and a sliding-rolling ratio of 50%. The test temperature was 37℃.

[0022] 2. Rapid gas chromatography electronic nose analysis Flavor differences among different salad dressing samples were detected using a rapid gas chromatography-electronic nose. 3 g of sample was placed in a 20 ml sampling vial and incubated at 60 °C for 30 min before analysis. The injection volume was 5 ml, administered via headspace injection. Data were processed using the electronic nose's accompanying software.

[0023] 3. Sensory analysis Ten experienced food professionals were invited to evaluate the differences in sensory properties among various salad dressing samples. Color, firmness, viscosity, flavor, and mouthfeel intensity were scored on a 10-point scale according to the criteria in Table 1.

[0024] Table 1 Scoring criteria for the five sensory attributes

[0025] Example 1 The preparation of DGSP particles includes the following: Diosgenin and SP were dissolved in chloroform at a 1:1 ratio. Then, at 45°C... o Evaporating chloroform at temperature C yields DGSP particles.

[0026] Example 2 The preparation of W / O-HIPE includes the following: In 120 o Under heating conditions (C), 3.0 wt% DGSP particles were dispersed in rapeseed oil. Subsequently, under stirring at 1200 rpm, 75% aqueous phase was dropwise dispersed into the rapeseed oil to obtain a water-oil mixture. The mixture was then homogenized at 12000 rpm for 5 min to obtain W / O-HIPE.

[0027] Example 3 The preparation methods for salad dressing include the following: The ingredients for making the salad dressing are: rapeseed oil (50 g), water (30 g), egg yolk powder (7 g), vinegar (3 g), white sugar (6.2 g), salt (1 g), xanthan gum (0.8 g), and modified starch (2 g). Mix all the ingredients together and beat for 4 minutes to obtain the salad dressing. Use W / O-HIPE instead of 10 wt%, 20 wt%, 30 wt%, 40 wt%, and 50 wt% of rapeseed oil to prepare a low-fat salad dressing.

[0028] Results Analysis 1. Appearance and microstructure of low-fat salad dressings with different oil phase substitution rates From the appearance ( Figure 1 The color of reduced-fat salad dressing samples with an oil phase replacement rate of 10-50% showed no significant difference from that of normal salad dressing samples. However, as the oil phase replacement rate increased, the self-supporting ability of the reduced-fat salad dressing samples decreased significantly. When the oil phase replacement rate exceeded 40%, the samples showed slight fluidity and began to collapse. This was due to the excessive reduction in the volume of the oil phase, as the oil phase is one of the main factors affecting the rheological properties of salad dressing. Figure 2 These are CLSM images of different salad dressing samples. The oil phase component is stained with Nile Red and appears red in the images, while the aqueous phase component is not stained and appears black. After beating, the red-stained spherical oil droplets in normal salad dressing are uniformly dispersed in the aqueous phase, indicating that the salad dressing is essentially an O / W emulsion. For the low-fat salad dressing samples, the number of droplets observed in the field of view gradually decreased as the oil phase substitution rate increased from 10% to 50%. In particular, when the oil phase substitution rate was 40-50%, the droplet size increased, and the droplet distribution became more sparse. This result is consistent with the aforementioned appearance changes. Due to the significantly larger droplet size, the interaction between droplets decreased, leading to a decrease in the viscoelasticity and self-supporting ability of the low-fat salad dressing samples. Furthermore, it is noteworthy that in all low-fat salad dressing samples, some tiny black water droplets (black) could be observed inside the red oil droplets. These water droplets originated from W / O-HIPE. This indicates that W / O-HIPE remains stable in the salad dressing without breaking down and plays a role in oil phase substitution.

[0029] 2. Rheological properties of low-fat salad dressings with different oil phase substitution rates The oil phase, as the dispersed phase in an O / W emulsion (salad dressing), has a significant impact on the texture of the emulsion. The viscosity and viscoelasticity of different salad dressing samples were characterized by measuring their rheological properties with an oil phase replacement rate of 10-50%.

[0030] from Figure 3It can be seen that the viscosity of all samples gradually decreases with increasing shear rate, exhibiting shear thinning characteristics. When W / O-HIPE replaces 10%-30% of the oil phase, the viscosity of the reduced-fat salad dressing sample is closest to that of the normal salad dressing sample. The viscosity decreases significantly with increasing oil phase substitution rate.

[0031] The viscoelasticity of O / W emulsions (salad dressing) is also affected by changes in the volume of the oil phase. (From frequency scanning...) Figure 3 From the viscosity measurements, G′ is consistently greater than G′′, indicating that both regular and reduced-fat salad dressings possess viscoelasticity. Rheological analysis shows that when the oil phase substitution rate is 10%-30%, the G′ and G′′ values ​​of the salad dressing are close to those of regular salad dressing, proving they have similar viscoelasticity. Based on the above viscosity measurements, reduced-fat salad dressings with an oil phase substitution rate of 10%-30% exhibit similar rheological properties to regular salad dressings. When the oil phase substitution rate increases to 40-50%, its G′ and G′′ values ​​are significantly lower than those of regular salad dressing. Excessive substitution of the oil phase volume causes a significant difference in rheological properties.

[0032] 3. LAOS analysis of low-fat salad dressings with different oil phase substitution rates During oral processing, food often undergoes greater deformation, such as chewing. Decomposing the shear stress waveform of the viscoelastic response yields the Lissajous curve, which provides detailed information about the instantaneous deformation of food during chewing.

[0033] Figure 4Elastic and viscous liissajous curves of low-fat salad dressings at different strains (1%, 10%, 100%, 500%) are shown. Solid and dashed lines represent total stress and post-decomposition elastic stress, respectively. Their shapes change with increasing strain. In the elastic liissajous curves, at strains of 1%–10%, normal salad dressing and low-fat salad dressing with 10%–30% oil phase substitution exhibit an extremely stretched olive shape, while the viscous liissajous curves show a circular shape. Furthermore, the post-decomposition elastic stress consists of straight lines, indicating its predominantly elastic properties. When the strain increases to 100% and 500%, the elastic liissajous curves of normal salad dressing and low-fat salad dressing with 10%–30% oil phase substitution transform into rounded rectangles. In their viscous liissajous curves, the viscous curves of these samples are elliptical and extremely stretched elliptical, respectively. This indicates that when the strain exceeds 100%, the samples transition from predominantly elastic behavior to viscous behavior until the internal structure completely collapses. Furthermore, the area of ​​the enclosed region increased as the salad dressing samples gradually softened. This simulates the chewing process in our mouths. Through continuous chewing, the salad dressing deforms more, changing from a solid to a liquid state, making it easier to swallow. Notably, the elasticity and viscosity lissajous curves of normal salad dressing and low-fat salad dressing with 10%-30% oil phase substitution overlapped and were similar in shape, indicating that these salad dressing samples exhibited similar instantaneous deformation during chewing.

[0034] However, the information regarding reduced-fat salad dressings with a 40%-50% oil phase replacement rate is completely different from that of normal salad dressings. In the elastic lissajous curves, the curves of reduced-fat salad dressings with a 40%-50% oil phase replacement rate transform into parallelograms and larger rounded rectangles at 100% and 500%. Their viscous lissajous curves also eventually become stretched ellipses. The curves of the reduced-fat salad dressing samples hardly overlap with those of normal salad dressings, exhibiting completely different shapes, indicating that they possess unique transient deformation characteristics. This is likely because the excessive reduction in oil phase volume leads to a looser network structure in the emulsion, further altering the viscosity and elastic properties of the emulsion, a fact also confirmed by rheological measurements.

[0035] 4. Tribological properties of low-fat salad dressings with different oil phase substitution rates Place a 3 / 4 soft silicone ball on the surface of a silicone disc (a skin substitute made of polyurethane elastomer that replicates the feel and elasticity of human skin) to provide the relationship between oral activity and the coefficient of friction.

[0036] like Figure 6The relationship between rolling speed and coefficient of friction is shown. Rolling speed was used to simulate the stirring motion of the tongue in the oral cavity. Since salad dressing is a non-Newtonian fluid, the coefficient of friction does not perfectly follow the classic Stribeck curve as a function of rolling speed. The tongue movement speed was 200 mm L / s. Therefore, the rolling speed in the measurement was extended to 1000 mm L / s. At lower rolling speeds (approximately 1-80 mm L / s), the coefficient of friction of all salad dressing samples decreased sharply, indicating that the samples were in a mixed friction state. At this stage, fluid entrainment was more pronounced, a lubricating film was further formed, and the coefficient of friction was lowest. Under hydrodynamic friction (>100 mm L / s), the gradually increasing rolling speed caused more salad dressing samples to be entrained into the contraction zone, resulting in a gradual increase in the coefficient of friction. It can be seen that the coefficient of friction of normal salad dressing and reduced-fat salad dressing with an oil phase substitution rate of 10%-30% showed similar trends. However, the reduced-fat salad dressing samples with an oil phase substitution rate of 40%-50% had a significantly lower coefficient of friction than normal salad dressing samples due to their loose network structure. Rheological measurements showed that both regular salad dressing and reduced-fat salad dressing with an oil phase replacement rate of 10%-30% had higher viscosity, which is beneficial for improving the coefficient of friction. The rheological properties of reduced-fat salad dressing with an oil phase replacement rate of 10%-30% were similar to those of regular salad dressing, with overlapping friction curves and similar lubricity. This measurement further demonstrates that even with a 30% oil replacement, the oral lubricity of salad dressing was not affected.

[0037] 5. Flavor of low-fat salad dressings with different oil phase substitution rates As is well known, oil phases play an important role in the flavor of food: (1) oil phases are very important for flavor perception because they are the carriers of many fat-soluble flavorings; (2) oil phases affect the order of aroma release, i.e., the aroma perception threshold; and (3) they help to change the way taste interacts with taste buds on the tongue. Electronic noses are often used to simulate human olfaction. Their sensors can capture small molecules released from samples that can produce flavor, providing low-cost, convenient, and rapid food flavor analysis. Therefore, this section evaluates the flavor of low-fat salad dressings with an oil phase substitution rate of 10%-50% using a rapid gas chromatography electronic nose.

[0038] Cluster analysis (CA) is a technique that attempts to group data into specific groups based on the similarity or distance between observations. The results of hierarchical clustering methods are typically displayed as dendrograms. In a dendrogram, the distance between different observations is measured to determine the similarity of the observations across various attributes. Figure 7In this study, based on the response signals of 10 sensors in an electronic nose to different salad dressing flavors, CA (flavor analysis) was used to classify normal and reduced-fat salad dressings. All salad dressing samples were divided into three groups at an Euclidean distance of 5.0. The first group included normal salad dressing and reduced-fat salad dressing samples with an oil phase substitution rate of 10%-30%. The second and third groups contained reduced-fat salad dressing samples with oil phase substitution rates of 40% and 50%, respectively. Samples within the same group exhibited similar electronic nose flavor response signals, displaying similar flavor characteristics. Therefore, CA provides an initial classification, despite the different groupings at different Euclidean distances.

[0039] Principal Component Analysis (PCA) is commonly used to analyze, classify, and reduce the dimensionality of multivariate numerical datasets. PCA can compress data based on their similarities and differences, reducing the number of dimensions with almost no loss of information, and defining the number of principal components. Using PCA to observe the similarity between salad dressing samples, the dimensionality was reduced from ten variables to two or three principal components, while retaining most of the original information in the dataset. The principal component score plot shows that principal component 1 and principal component 2 account for 77.22% and 19.67% of the total variance, respectively, contributing a total of 96.89%, providing sufficient information about the samples. Figure 7 As can be seen, the flavor datasets of all samples were divided into three groups: a 50% oil phase substitution rate group, a 40% oil phase substitution rate group, and a normal salad dressing group with an oil phase substitution rate of 10%-30%, indicating significant differences in flavor characteristics among the different groups of salad dressing samples. Combining the CA and PCA analysis results, the flavor characteristics of the reduced-fat salad dressing samples with an oil phase substitution rate of 10%-30% were similar to those of the normal salad dressing, and they were grouped into the same group.

[0040] 6. Sensory characteristics of low-fat salad dressings with different oil phase substitution rates Sensory analysis was conducted on five sensory attributes: color, firmness, viscosity, flavor, and texture, for both normal salad dressing (control group) and low-fat salad dressing. Figure 8 It can be seen that there is no significant difference in color between the different samples. p >0.05). There were no significant differences in hardness, viscosity, flavor, and mouthfeel properties between low-fat salad dressing samples with an oil phase substitution rate of 10%-30% and normal salad dressing samples. p >0.05), but when the oil phase substitution rate exceeded 40%, all of the above properties decreased significantly. p <0.05). This finding is consistent with all the measurements mentioned above. Using W / O-HIPE as an oil phase substitute, the maximum replacement rate of the oil phase volume fraction in salad dressings can reach 30%. More importantly, these low-fat salad dressings are similar to regular salad dressings in various properties. W / O-HIPE is a qualified fat substitute that reduces the fat content in salad dressings without affecting the properties of the dressing.

[0041] The embodiments provided above are not intended to limit the scope of the invention, nor are the described steps intended to limit the order of execution. Any obvious modifications made to the invention by those skilled in the art based on existing common knowledge also fall within the scope of protection defined by the claims.

Claims

1. A method for preparing a high internal phase water-in-oil emulsion, characterized in that, The method includes the following: (1) Dissolve diosgenin and SP in chloroform, then evaporate the chloroform to obtain DGSP particles; (2) Disperse the DGSP particles prepared in step (1) into rapeseed oil, and then disperse the aqueous phase dropwise into rapeseed oil to obtain a water-oil mixture. Then shear emulsify to obtain W / O-HIPE.

2. The method according to claim 1, characterized in that, The mass ratio of diosgenin and SP in step (1) is 1:

1.

3. The method according to claim 1, characterized in that, The evaporation temperature in step (1) is 40~50℃.

4. The method according to claim 1, characterized in that, The amount of DGSP particles added in step (2) is 3.0 wt%.

5. The method according to claim 1, characterized in that, The proportion of the aqueous phase in step (2) is 75%.

6. The W / O-HIPE obtained according to any one of claims 1 to 5.

7. The application of the W / O-HIPE as described in claim 6 in food processing.

8. A method for preparing a low-fat salad dressing, characterized in that, The method includes: The low-fat salad dressing is obtained by mixing and beating rapeseed oil, the W / O-HIPE of claim 6, water, egg yolk powder, vinegar, white sugar, edible salt, xanthan gum and deformed starch evenly.

9. The method according to claim 8, characterized in that, The amount of W / O-HIPE used is 10-50 wt% of rapeseed oil.

10. The low-fat salad dressing prepared by the method of claim 8 or 9.

Images