Application of OSA modified kudzuvine root starch in preparation of egg-free mayonnaise and preparation method of OSA modified kudzuvine root starch

Abstract

The invention provides an application of OSA modified pueraria starch in preparation of egg-free mayonnaise. The invention also provides a preparation method of the egg-free mayonnaise, the egg-free mayonnaise is processed by using octenyl succinic anhydride modified pueraria starch particles to replace the egg-free mayonnaise yellow, and the preparation method comprises the following steps: preparing the octenyl succinic anhydride modified pueraria starch particles; vinegar, salt, sugar and the octenyl succinic anhydride modified kudzuvine root starch particles are dissolved in water, homogenization is conducted for 1-2 min at the speed of 100000-120000 r / min, and the mass concentration of the octenyl succinic anhydride modified kudzuvine root starch particles is 2.5%-4.5%; and adding soybean oil with the volume fraction of 60% into the mixture, and then homogenizing under 30MPa for 2-3 times to prepare the egg-free yolk sauce. According to the egg-free mayonnaise disclosed by the invention, the problems of stability and quality when the existing yolk substitute is applied to the mayonnaise are solved, so that the quality of the prepared egg-free mayonnaise is better.

Description

Technical Field

[0001] The present invention relates to the technical field of food processing, and particularly relates to the application of OSA-modified kudzu starch in the preparation of eggless mayonnaise and its preparation method. Background Art

[0002] Mayonnaise is a typical oil-in-water (O / W) emulsion gel. Traditional mayonnaise uses egg yolk or whole egg as an emulsifying stabilizer. The phospholipids in the egg yolk have a strong emulsifying effect, thus forming a stable emulsion. However, the relatively high cholesterol and saturated fatty acid content in the egg yolk will increase the risk of human obesity and cardiovascular diseases. When preparing the emulsion, the protein requires steps such as adjusting the pH value, which is rather cumbersome. Therefore, from the perspectives of human health and environmental sustainable development, using starch to partially or completely replace the egg yolk in the preparation of mayonnaise has attracted wide attention from food scientists.

[0003] However, the cholesterol and saturated fatty acid content in the egg yolk of traditional mayonnaise is high, and excessive intake poses a threat to human health. With the improvement of consumers' health awareness and the increase in special dietary needs, such as the increase in the number of vegetarians and people allergic to eggs, traditional egg-containing mayonnaise can no longer meet the needs of all consumers. Therefore, the development of eggless mayonnaise has a broad market prospect and has become the trend and focus of current research. There have been relevant reports on plant proteins and dietary fiber in soybean dregs. However, the eggless mayonnaise prepared with the above-mentioned egg yolk substitutes still has differences in texture and sensory quality compared with traditional mayonnaise, resulting in its inability to meet consumers' needs in terms of texture, taste, etc.

[0004] In recent studies on Pickering emulsion gels, it has been found that Pickering emulsion gels prepared with food-grade Pickering particles have the potential to simulate the rheological and textural properties of traditional mayonnaise. However, such eggless mayonnaise of the Pickering emulsion gel type still has differences in flavor and taste compared with traditional mayonnaise, and when stored for a long time or affected by extreme environmental conditions, stability problems such as oil phase separation and gel structure damage may still occur in the eggless mayonnaise.

[0005] In view of this, it is necessary to provide a new process to solve the above technical problems.

[0006] In view of this current situation, there is still a need to develop a new type of food-grade Pickering particle that can replace the egg yolk, with a view to preparing high-quality eggless mayonnaise. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide the application of an emulsified kudzu starch in mayonnaise, which can prepare high-quality eggless mayonnaise.

[0008] The first aspect of the present invention is to provide an application of octenyl succinic anhydride modified kudzu starch in the preparation of eggless mayonnaise.

[0009] The second aspect of the present invention is to provide a method for preparing eggless mayonnaise, comprising the following steps:

[0010] Step S1, preparing octenyl succinic anhydride modified kudzu starch granules;

[0011] Step S2, dissolving vinegar, salt, sugar, and the octenyl succinic anhydride modified kudzu starch granules prepared in step S1 in water, and homogenizing at 100000 - 120000 r / min for 1 - 2 min, wherein the mass concentration of the octenyl succinic anhydride modified kudzu starch granules is 2.5 - 4.5%;

[0012] Step S3, adding soybean oil with a volume fraction of 60% to the mixture in step S2, and then homogenizing 2 - 3 times at 30 MPa to prepare eggless mayonnaise.

[0013] Further, in step S2, the mass concentration of the octenyl succinic anhydride modified kudzu starch granules is 4%.

[0014] Further, in step S1, preparing the octenyl succinic anhydride modified kudzu starch granules includes the following steps:

[0015] Step S11, preparing emulsified kudzu starch;

[0016] Step S12, preparing a starch aqueous dispersion from the emulsified kudzu starch prepared in step S11;

[0017] Step S13, adjusting the pH of the starch aqueous dispersion to 8 - 8.2, and then adding octenyl succinic anhydride with a volume concentration of 5 - 9%;

[0018] Step S14, after the reaction, adjusting the pH of the system to 6 - 6.5, and obtaining octenyl succinic anhydride modified kudzu starch granules after washing, drying, pulverizing, grinding, and sieving.

[0019] Further, in step S11, the emulsified kudzu starch is prepared by a combined enzymatic hydrolysis and acid hydrolysis process.

[0020] Further, the preparation of the emulsified kudzu starch includes the following steps:

[0021] Preparing a buffer solution with a pH of 4 - 5 using Na2HPO4 and citric acid, dispersing kudzu starch in the buffer solution, and successively adding glucoamylase and α - amylase to enzymatically hydrolyze the kudzu starch dispersion to obtain an enzymatic hydrolysate;

[0022] Adjusting the pH of the enzymatic hydrolysate to neutral, and obtaining enzymatically pretreated kudzu starch after washing and drying;

[0023] An appropriate amount of sulfuric acid solution is added to the enzyme-pretreated kudzu starch. After mixing evenly, hydrolysis is carried out at 40 - 45 °C for 24 - 48 h, and then emulsified kudzu starch is obtained through centrifugation, washing, and freeze-drying.

[0024] Furthermore, during the enzymatic hydrolysis process, the total amount of enzyme accounts for 2 - 3% of the total amount of kudzu starch.

[0025] Furthermore, the ratio of glucoamylase to α - amylase is 3:1.

[0026] Furthermore, the added mass of the sulfuric acid solution is 14.3% of the mass of the enzyme-pretreated kudzu starch, and the concentration of the sulfuric acid solution is 3.16 mol / L.

[0027] Furthermore, in step S13, the volume concentration of octenyl succinic anhydride is 7%.

[0028] Compared with the prior art, the preparation method of the eggless mayonnaise provided by the present invention has the beneficial effects that:

[0029] First, the preparation method of the eggless mayonnaise provided by the present invention uses octenyl succinic anhydride-modified kudzu starch granules as an egg yolk substitute to prepare eggless mayonnaise, overcoming the stability and quality problems existing in the application of existing egg yolk substitutes in mayonnaise, and making the prepared eggless mayonnaise have better quality. Description of the Drawings

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0031] Figure 1 It is the SEM micrograph of the microstructure of the emulsified kudzu starch in Example 1 of the present invention;

[0032] Figure 2 It is the schematic diagram of the water contact angle of the emulsified kudzu starch in Example 1 of the present invention;

[0033] Figure 3 It is the influence of different GM and AMG ratios and sulfuric acid hydrolysis time on the starch Zeta potential in Example 1 of the present invention (A3: hydrolysis for 24 h; A4: hydrolysis for 48 h);

[0034] Figure 4 It is the influence of different GM and AMG ratios and sulfuric acid hydrolysis time on the stability of Pickering emulsion in Example 1 of the present invention;

[0035] The centrifuge tubes are, from left to right: Emul G1A0_24 、Emul G3A1_24 、Emul G1A3_24 、Emul G0A1_24 、Emul G1A0_48 、Emul G3A1_48 、Emul G1A3_48 、Emul G0A1_48 ;

[0036] Figure 5 show the effects of different OSA modification concentrations on the microstructure of kudzu starch in Example 2 of the present invention;

[0037] Figure 6 show the effects of different OSA modification concentrations on the water contact angle of kudzu starch in Example 2 of the present invention;

[0038] Figure 7 show the effects of different OSA modification concentrations on the centrifugal stability of emulsions and emulsion gels under different environmental conditions in Example 2 of the present invention;

[0039] The centrifuge tubes are, from left to right, Emul G3A1_48 、EOS 5-G3A1_48 、EOS 7-G3A1_48 、EOS 9-G3A148 ;

[0040] Figure 8 show the effects of different OSA modification concentrations on the heating stability of emulsions and emulsion gels under different environmental conditions in Example 2 of the present invention;

[0041] The centrifuge tubes are, from left to right, Emul G3A1_48 、EOS 5-G3A1_48 、EOS 7-G3A1_48 、EOS 9-G3A1 48;

[0042] Figure 9 show the effects of different OSA modification concentrations on the storage stability (A1, B1, and C1 stored for 0 d, A2, B2, and C2 stored for 30 d) of emulsions and emulsion gels under different environmental conditions in Example 2 of the present invention;

[0043] The centrifuge tubes are, from left to right, Emul G3A1_48 、EOS 5-G3A1_48 、EOS 7-G3A1_48 、EOS 9-G3A148 ;

[0044] Figure 10 show the effects of different OSA modification concentrations on the freeze-thaw stability (A1, B1, C1: freeze-thaw 1 time, B2: freeze-thaw 2 times, B3: freeze-thaw 3 times) of emulsions and emulsion gels under different environmental conditions in Example 2 of the present invention;

[0045] The centrifuge tubes are Emul from left to right in sequence G3A1_48 、EOS 5-G3A1_48 、EOS 7-G3A1_48 、EOS 9-G3A148 ;

[0046] Figure 11 is the particle size distribution diagram of CM and YFM in Example 3 of the present invention;

[0047] Figure 12 is the microstructure diagram of CM and YFM in Example 3 of the present invention. The particles stained with Nile blue show blue regions, and the oil phase stained with Nile red shows green regions;

[0048] Figure 13 is the apparent viscosity of CM and YFM in Example 3 of the present invention;

[0049] Figure 14 is the physical stability of CM and YFM in Example 3 of the present invention;

[0050] Figure 15 is the POV value and TBARS value of CM and YFM during oxidative storage in Example 3 of the present invention (A2: POV value, B2: TBARS value);

[0051] Figure 16 is the thermal stability of CM and YFM in Example 3 of the present invention;

[0052] Figure 17 is the freeze-thaw stability of CM and YFM in Example 3 of the present invention (A1: freeze-thaw 1 time, A2: freeze-thaw 2 times, A3: freeze-thaw 3 times);

[0053] Figure 18 is the visual appearance diagram of CM and YFM in Example 3 of the present invention. Detailed implementation manners

[0054] In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention and make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, the following further describes the detailed implementation manners of the present invention.

[0055] In the ranges disclosed herein, the endpoints and any values are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0056] Example 1 Preparation of emulsified kudzu starch

[0057] A preparation method of emulsified kudzu starch, comprising the following steps:

[0058] Prepare a buffer solution with pH = 4.5 using 0.2 moL / L Na2HPO4 and 0.1 moL / L citric acid. Slowly add the buffer solution to a 250 mL conical flask containing 40 g of kudzu starch PLS. After mixing evenly, add glucoamylase GM and react at the optimal temperature of GM, which is 55 °C, for 4 h. After the enzymatic hydrolysis is completed, adjust the pH of the solution to 1.5 with 2 M hydrochloric acid, inactivate the enzyme for 30 min, then adjust the pH = 6.5, set the temperature to the optimal temperature of α-amylase AMG, which is 37 °C, add AMG and react for 4 h to obtain an enzymatic hydrolysate; the total amount of enzymes accounts for 2.6% of the total amount of kudzu starch, and the mass ratios of glucoamylase GM to α-amylase AMG are 1:0, 3:1, 1:3, and 0:1 respectively;

[0059] After cooling, adjust the pH of the enzymatic hydrolysate to 7 with 1 mol / L NaOH, obtain enzyme-pretreated starch by suction filtration, and after drying in an oven at 45 °C, obtain enzyme-pretreated kudzu starch;

[0060] Weigh the enzyme-pretreated kudzu starch into a beaker, slowly add 3.16 mol / L sulfuric acid, and the addition amount of sulfuric acid accounts for 14.3% of the total starch. After mixing evenly, perform acid hydrolysis at 40 °C for 24 h and 48 h respectively, centrifuge at 10000 r / min for 10 min. To remove the residual sulfuric acid, wash with distilled water until the supernatant is neutral, and finally freeze-dry for 48 h to obtain 8 kinds of emulsified kudzu starch, which are respectively denoted as: GSt G1A0_48 、GSt G1A3_48 、GSt G0A1_48 、GSt G3A1_48 、GSt G1A0_24 、GSt G3A1_24 、GSt G1A3_24 、GSt G0A1_24 。

[0061] The SEM images of the microstructure of each emulsified kudzu starch are as shown in Figure 1 shown. It can be seen from Figure 1 that when the starch is treated by the combined enzymatic hydrolysis and acid hydrolysis, there are many wrinkles and cracks on the particle surface, and even local collapse, indicating that the combined action of enzymatic hydrolysis and acid hydrolysis leads to the hydrolysis of the amorphous region and part of the crystalline region of the starch particles. When the acid hydrolysis time increases from 24 h to 48 h, the long-time sulfuric acid hydrolysis causes the particles to disintegrate severely, the surface completely collapses, the particles stick together in groups, forming irregular fragments or gelatinized structures, and the particle size decreases significantly. Among them, the particle size of Gst G3A1_48 is the smallest and the size is uniform.

[0062] The water contact angles of each emulsified kudzu starch are as shown in Figure 2 shown. It can be seen fromFigure 2 It can be seen that under the same hydrolysis conditions, the contact angle differences of different GM and AMG ratios are relatively small, indicating that the strong erosion effect of sulfuric acid hydrolysis dominates the surface properties. Under the same enzymatic hydrolysis conditions, when the acid hydrolysis time increases from 24 h to 48 h, the water contact angle of starch increases up to 44.73° at most, indicating that the continuous action of sulfuric acid leads to the fragmentation of starch granules, the reduction of surface energy, the increase of hydrophobic segments, and the weakening of hydrophilicity. During the emulsification process of Pueraria lobata starch, enzymatic hydrolysis specifically cleaves α-1,4 and α-1,6 glycosidic bonds to form uniform pores or weak regions, and this pre-modification provides more erosion sites for subsequent acid hydrolysis, accelerating particle disintegration and surface roughening. The strong acidity of acid hydrolysis further expands the pores generated by enzymatic hydrolysis to form deep cracks or fragmented structures, enhancing the surface irregularity and resulting in a significant increase in the contact angle. When the acid hydrolysis time increases from 24 h to 48 h, long-term acid hydrolysis exacerbates particle disintegration and hydrophobic group enrichment, and the contact angle further increases. And by Figure 2 It can be seen that Gst G3A1_48 has the largest contact angle.

[0063] The effects of different GM and AMG ratios and sulfuric acid hydrolysis time on the Zeta potential of starch are as Figure 3 shown. The absolute value of the potential of double enzyme hydrolysis is greater than that of single enzyme hydrolysis. When the AMG content in GM / AMG increases, the absolute value of the potential of starch shows a trend of first increasing and then decreasing; in the starch of enzymatic hydrolysis combined with sulfuric acid hydrolysis for 24 h, when GM / AMG is 3:1, the absolute value of the potential of Gst G3A1_24 is the largest, reaching 29.1 mV. When the sulfuric acid hydrolysis time increases from 24 h to 48 h, the absolute value of the potential of starch decreases, with a maximum decrease of 3.4 mV. And in the starch of enzymatic hydrolysis combined with sulfuric acid hydrolysis for 48 h, the absolute value of the potential of Gst G3A1_48 is the largest, reaching 26.6 mV. This is because when the sulfuric acid hydrolysis time is 24 h, due to insufficient sulfuric acid hydrolysis, the starch granule structure still retains a certain degree of integrity, the size and shape of the granules are relatively stable, and the charge distribution on the granule surface is relatively concentrated, which can better maintain a higher potential.

[0064] Pickering emulsion stability

[0065] Pickering emulsion preparation process: Weigh a certain mass of emulsified Pueraria lobata starch and prepare a 1% starch solution with distilled water. After treating it with a high-speed shearer at 10000 r / min for 1 min, add soybean oil with an oil phase of 0.2. Then, treat it with a high-speed shearer at 10000 r / min for 2 min and perform high-pressure homogenization at 30 MPa for 3 times to prepare different types of Pickering emulsions.

[0066] The effects of different GM and AMG ratios and sulfuric acid hydrolysis time on the stability of Pickering emulsion are asFigure 4 As shown, a small amount of oil separated out on the upper layer of the starch emulsion after enzymatic hydrolysis combined with sulfuric acid hydrolysis for 24 h. Under the same enzymatic hydrolysis conditions, when the sulfuric acid hydrolysis time increased from 24 h to 48 h, no obvious delamination phenomenon occurred in the combined starch emulsion, where Emul G3A1_48 showed good stability. After storing for 30 d, Emul G3A1_48 had no obvious oil separation, indicating that the starch granules prepared under these conditions could be more evenly dispersed at the oil-water interface to form a dense interfacial film. Some granules left the oil-water interface due to aggregation or sedimentation, resulting in an increase in the water layer. However, because the interfacial film formed by the granules was relatively firm, it effectively blocked the mutual collision between droplets, thus prolonging the stability time of the emulsion and preventing the phenomenon of oil separation. In addition, through mechanisms such as three-dimensional viscoelastic networks among the granules, the viscosity of the emulsion was increased and the moving rate of the emulsion droplets was reduced, further enhancing the stability of the emulsion.

[0067] It can be seen that after high-speed centrifugation of the fresh Pickering emulsions prepared from kudzu starch with different GM and AMG ratios and sulfuric acid hydrolysis times, the emulsion layer did not collapse, indicating its good ability to resist external forces. Emul G3A1_48 There was no oil on the surface after centrifugation, the emulsion layer was thick, and the aqueous phase was relatively clear. The centrifugal stability results proved that Emul G3A1_48 had good stability.

[0068] It can be seen that after adding 100 mM NaCl to the fresh Pickering emulsions prepared from kudzu starch with different GM and AMG ratios and sulfuric acid hydrolysis times, the emulsion layer was relatively thick and no precipitate was formed at the bottom. This was because after enzymatic hydrolysis of amylase and then sulfuric acid hydrolysis, the number of surface charges on the granules increased, and these charges had a stronger interaction with NaCl, enhancing the stability of the emulsion.

[0069] It can be seen that the fresh Pickering emulsions prepared from kudzu starch with different GM and AMG ratios and sulfuric acid hydrolysis times were in an acidic condition. The emulsion emulsification layer was thick, there was no obvious oil separation on the surface, and no precipitate was formed at the bottom, indicating that it was relatively stable in an acidic environment.

[0070] In summary, it can be seen that Emul G3A1_48 had the optimal stability.

[0071] Preparation of OSA-modified kudzu starch granules in Example 2

[0072] A preparation method of OSA-modified kudzu starch granules includes the following steps:

[0073] Take 30 g of the emulsified kudzu starch Gst prepared in Example 1 G3A1_48, Prepare a 10 wt% starch aqueous dispersion, control the reaction temperature at 30 °C and the stirring speed using a magnetic stirring water bath, adjust the pH of the starch aqueous dispersion to 8 - 8.2 with a 3 wt% NaOH solution, and then slowly add octenyl succinic anhydride (OSA) with volume concentrations of 0%, 5%, 7%, and 9%. During the addition process, keep the pH and temperature at the set points. After the reaction, adjust the system to a pH of about 6.5 with 3 mol / L HCl solution, wash it three times with distilled water, absolute ethanol, and distilled water respectively, and then dry the product in an oven at 45 °C, pulverize, grind, and sieve it to obtain four kinds of octenyl succinic acid starches (GOS): Gst G3A1_48 , GOS 5-G3A148 , GOS 7-G3A1_48 , GOS 9-G3A1_48 .

[0074] The influence of different OSA modification concentrations on the microstructure of kudzu starch is as shown in Figure 5 . As can be seen from Figure 5 , after modification with OSA, with the increase in OSA concentration, the surface roughness of GOS gradually increases, and the holes and cracks gradually increase. Therefore, the destructive effect of high-concentration OSA on the starch granule structure is more significant.

[0075] The influence of different OSA modification concentrations on the water contact angle of kudzu starch is as shown in Figure 6 . As can be known from Figure 6 , when the starch is modified with OSA, with the increase in OSA modification concentration, the contact angle of EOS gradually increases, indicating that high-concentration OSA modification significantly increases the hydrophobicity of starch.

[0076] Stability of Pickering emulsions prepared with OSA-modified kudzu starch

[0077] Preparation of Pickering emulsions:

[0078] Weigh a certain mass of four kinds of octenyl succinic acid starches (GOS), prepare a 4% starch solution with distilled water, treat it with a high-speed shear mixer at 10000 r / min for 1 min, then add soybean oil, set the oil-water ratio to 0.6, and then treat it with a high-speed shear mixer at 10000 r / min for 2 min, and then immediately use a high-pressure homogenizer at 30 MPa three times to obtain Pickering emulsions and emulsion gels.

[0079] The prepared emulsions and emulsion gels are respectively denoted as: Emul G3A1_48 , EOS 5-G3A1_48 , EOS 7-G3A148 , EOS 9-G3A1_48 .

[0080] The Pickering emulsion was centrifuged at 5000 r / min for 30 min, and the layering of the emulsion was observed. The effects of different OSA modification concentrations on the centrifugal stability of the emulsion and emulsion gel under different environmental conditions are as Figure 7 shown. As Figure 7 can be seen, after centrifugation, the emulsified layer gradually thickened with the increase of the modification concentration. In the original environment, salt concentration, and acidic environment, no oil separated out on the surface of the Pickering emulsion. As the OSA modification concentration increased from 5% to 9%, the emulsified layer of the Pickering emulsion gradually thickened. This is because in the salt environment, salt ions can play an electrostatic shielding role on the charge on the droplet surface, reducing the electrostatic repulsion between droplets, enabling the droplets to be arranged more closely, thereby enhancing the stability of the emulsion; in the acidic environment, the stability of the Pickering emulsion is enhanced compared to the original environment. This is because in the acidic environment, the carboxyl succinic groups on the surface of the OSA-modified starch particles may undergo protonation or hydrolysis reactions, resulting in an increase in the charge density on the droplet surface and an enhancement of the electrostatic repulsion between droplets, thus inhibiting the aggregation of droplets and improving the stability of the emulsion.

[0081] Through the study of the centrifugal stability of the Pickering emulsion, it can be concluded that EOS 5-G3A1_48 、EOS 7-G3A1_48 、EOS 9-G3A1_48 have good stability in the three environments.

[0082] The Pickering emulsion was heated at 85 °C for 1 h, and the layering phenomenon of the emulsion was observed. The effects of different OSA modification concentrations on the heating stability of the emulsion and emulsion gel under different environmental conditions are as Figure 8 shown. As Figure 8 can be seen, the stability of the Pickering emulsion increases with the increase of the OSA concentration, and EOS 5-G3A148 、EOS 7-G3A1_48 、EOS 9-G3A1_48 have good stability in the three environments.

[0083] The Pickering emulsion was stored at 25 °C for 30 days, and whether obvious layering occurred during the observation period was observed. The effects of different OSA modification concentrations on the storage stability of the emulsion and emulsion gel under different environmental conditions are as Figure 9 shown. As Figure 9 can be known, at 0 d of storage, EOS 7-G3A1_48 can be inverted; after 30 d of storage, EOS 5-G3A1_48 、EOS 7-G3A1_48 、EOS 9-G3A1_48 have good stability in the three environments.

[0084] The Pickering emulsions and emulsion gels were placed at -18 °C for 22 hours and thawed at 25 °C for 2 hours, and this cycle was repeated one to three times. The freeze-thaw stability of the emulsions and emulsion gels was observed. The effects of different OSA modification concentrations on the freeze-thaw stability of the emulsions and emulsion gels under different environmental conditions are as Figure 10 shown. As Figure 10 can be seen, GOS G3A1_48 remained stable without deformation after 2 freeze-thaw cycles. After the third freeze-thaw cycle, slight oil separation occurred on the surface, while GOS 7-G3A1_48 remained stable without deformation after 3 freeze-thaw cycles. This is because water freezes below 0 °C. When ice crystals form in the aqueous phase of the starch granule emulsion with water as the dispersion medium, the emulsion droplets are surrounded by ice crystal particles. In an acidic environment, ice crystals will form in the hydration layer at the oil-water interface, and H + ions cannot prevent this from happening. At the same time, the ice crystals in the continuous phase will squeeze the droplets. Therefore, the emulsion cannot return to its previous state after thawing. In a salt concentration environment, NaCl, as a strong electrolyte, can not only increase the viscosity of the emulsion to resist external deformation, but also lower the ice crystal point of the aqueous solution in the aqueous phase and reduce the damage caused by ice crystals. GOS 7-G3A1_48 In a salt environment, the ice crystals in the emulsion are relatively weak, and the hydration layer on the oil-water interface becomes thinner or even disappears, preventing the formation of ice crystals, making the emulsion gel have good freeze-thaw stability. Therefore, the freeze-thaw stability of the emulsion gel in a salt concentration environment is better than that in an acidic condition.

[0085] Determination of thixotropy-recovery

[0086] The measurement was carried out using a rheometer equipped with parallel plates (diameter 40 mm, gap 1000 μm). The measurement was divided into three stages. The first stage was in the linear viscoelastic region (LVR), and the specific measurement parameters were as follows: the constant strain was 0.5%, the angular frequency was 10 rad / s, and the measurement time was 120 s; the second stage was in the non-linear viscoelastic region (non-LVR), and the specific measurement parameters were as follows: the constant strain was 10%, the angular frequency was 10 rad / s, and the measurement time was 30 s; the third stage was also in the LVR, and the specific measurement parameters were as follows: the constant strain was 0.5%, the angular frequency was 10 rad / s, and the measurement time was 450 s; finally, the change of G′ with time of the Pickering emulsion gel in the three measurement stages was obtained. The thixotropy-recovery rate (%) Rec 120 ) of the Pickering emulsion gel at 120 s in the third stage after 30 s of deformation can be calculated through the formula:

[0087]

[0088] In the formula: G i is the G′ of mayonnaise at the initial state in the first stage;

[0089] G 120 is the G′ of mayonnaise at 120s in the third stage.

[0090] The thixotropy-recovery rate of the latex gel prepared under different environmental conditions with different OSA modification concentrations is shown in Table 1:

[0091] Table 1: Thixotropy-recovery rate of latex gels prepared under different environmental conditions with different OSA modification concentrations

[0092]

[0093] Among them, EOS 100-5-G3A148 EOS 100-7-G3A1_48 EOS 100-9-G3A1_48 Respectively represent the emulsion gel under 100 nM NaCl conditions, EOS 3-5-G3A1_48 EOS 3-7-G3A148 EOS 3-9-G3A1_48 They represent the emulsion gel under the condition of pH=3 respectively.

[0094] As shown in Table 1, under the original environment, EOS 7-G3A1_48 %Rec 120 The maximum is 99.01%; under salt concentration and acidic environment, the %Rec of emulsion gel 120 The same trend was shown, and the %Rec 120 Greater than the %Rec of the latex gel in the original environment 120 . This result shows that the greater the thixotropic recovery rate, the faster the system rebuilds the damaged structure between particles after the stress is stopped, and the higher its stability. And in the salt concentration environment, salt ions promote structural recovery by interacting with charged particles in the emulsion gel. The acidic environment changes the interaction force between the emulsion gel molecules, the functional groups in the starch structure will be protonated, and new electrostatic interactions will be generated between the particles, making it easier for the particles to approach each other, thereby promoting structural recovery.

[0095] Determination of creep-recovery

[0096] The creep-recovery test was carried out using a rheometer equipped with parallel plates (diameter 40 mm, gap 1000 μm). The creep-recovery test was divided into a creep stage and a recovery stage. A constant shear stress of 0.7 Pa was applied to the Pickering emulsion gel, and the change of deformation over time within 120 s was recorded; in the recovery stage, the initial constant stress was removed, and the change of deformation over time within 240 s was recorded; and the creep-recovery (%Rec) of the Pickering emulsion gel at the end of the recovery stage can be calculated by the formula c ):

[0097]

[0098] Where: γ max is the maximum elastic deformation of the Pickering emulsion gel in the creep stage;

[0099] γ e is the elastic deformation at equilibrium of the Pickering emulsion gel in the recovery stage.

[0100] The creep-recovery rates of emulsion gels prepared at different OSA modification concentrations under different environmental conditions are shown in Table 2:

[0101] Table 2: Creep-recovery rates of emulsion gels prepared at different OSA modification concentrations under different environmental conditions

[0102]

[0103] As can be seen from Table 2, the maximum %Recc of EOS 100-7-G3A1_48 is 96.72%, followed by EOS 100-9-AH48 with %Recc of 93.26%, and under different environments, the maximum %Recc is always the emulsion gel prepared by GOS 7-G3A1_48 In addition, %Recc in the salt concentration environment is greater than that in the original environment and the acidic environment. This is because salt ions can promote the aggregation of particles in the emulsion gel to form a more ordered network structure. In the creep stage, this stable network structure can better resist deformation and reduce the degree of deformation.

[0104] From the thixotropic-recovery and creep-recovery properties, it can be seen that EOS 7-G3A1_48 has strong recovery ability, especially in the high-salt concentration and low-pH environment, EOS 7-G3A1_48 has strong storage, recovery and thermal stability. In summary, the emulsion stability of EOS 7-G3A1_48 is the best.

[0105] Example 3 Preparation of eggless mayonnaise

[0106] A method for preparing eggless mayonnaise, comprising the following steps:

[0107] Mix 37 vol% deionized water with 3 vol% white vinegar, and weigh a certain amount (2.50, 3.00, 3.50, 4.00, 4.50 wt%) of GOS 7-G3A1_48 , 8 wt% table salt and 8 wt% granulated sugar, treat with a high-speed shear machine at 10000 r / min for 1 min, then add 60 vol% soybean oil, and then homogenize 3 times at 30 MPa using a high-pressure homogenizer to obtain 5 YFMs with different GOS concentrations, and name them YFM 7-G3A1_48-2.50 , YFM 7-G3A1_48-3.00 , YFM7-G3A1_48-3.50 、YFM 7-G3A1_48-4.00 、YFM 7-G3A1_48-4.50 .

[0108] Commercial mayonnaise (CM) was used as a control for the following analysis.

[0109] The particle size distribution of CM and YFM is as follows Figure 11 As shown, when GOS 7-G3A1_48 When the concentration of YFM increases from 2.50wt% to 4.50wt%, the d 4,3 It is reduced from 4.59μm to 3.56μm, which is much smaller than the d of CM. 4,3 This indicates that the droplet size of YFM decreases with the increase of particle concentration, and the YFM particles can be regulated by adjusting the GOS concentration. The smaller the particle size of mayonnaise, the higher its emulsification stability and the more delicate the taste.

[0110] The microstructures of CM and YFM are shown in Figure 12 As shown in the CLSM image, the aqueous phase is not stained and is therefore represented by a black area, the blue markers represent the stained yolk or GOS, and the green markers represent the stained oil droplets. Figure 12 It can be seen that the oil droplets in CM present irregular shapes, and the egg yolk is not only adsorbed on the surface of the oil droplets, but also flocculated in the continuous phase. GOS forms an interfacial adsorption layer of a certain thickness around the oil droplets, and the oil droplets are spherical, indicating that YFM is an oil-in-water (O / W) type, and GOS does not flocculate in the continuous phase. When the concentration of GOS increases, the droplet size of YFM is slightly smaller, and the number of particles in the continuous phase increases. This shows that the stability of YFM is higher than that of CM. When the volume fraction of the oil phase is constant, the increase in particle concentration allows a sufficient number of particles to be adsorbed on the oil-water interface. When the concentration reaches saturation and further increases, excess particles are dispersed in the continuous phase to form a three-dimensional network structure, thereby further increasing the stability of YFM.

[0111] The apparent viscosity of CM and YFM is Figure 13 As shown in Figure 2, the viscosity of all emulsions decreases with increasing shear rate. When the concentration of GOS particles is 4.50wt%, the YFM 7-G3A1_48-4.50 The viscosity of YFM is greater than that of CM; when the particle concentration is 4.00wt%, 7-G3A1_48-4.00 The viscosity of YFM is similar to that of CM. However, when the concentration of GOS particles is 2.50wt%, 3.00wt%, and 3.50wt%, the viscosity of YFM is less than that of CM, and 7-G3A1_48-3.50 >YFM 7-G3A1_48-3.00 >YFM 7-G3A1_48-2.50 From the perspective of viscosity, YFM 7-G3A1_48-4.00 Similar to CM, and thus closer to CM in taste.

[0112] Thixotropic tests and creep tests can represent the speed and degree of the structure recovery of the sample after the shear stress is stopped and the deformation behavior under continuous stress, which are very important for the stability and texture characteristics of mayonnaise and can reveal the ability of mayonnaise to gradually return to its original state after agitation. The thixotropic-recovery rate and creep-recovery rate of CM and YFM are shown in Table 3:

[0113] Table 3: Thixotropic-recovery rate and creep-recovery rate of CM and YFM

[0114]

[0115] As can be seen from Table 3, the %Rec of CM 120 can be as high as 106.07%. When the concentration of GOS 7-G3A1_48 increases from 2.50 wt% to 4.50 wt%, the %Rec of YFM 120 increases from 79.29% to 107.97%. This indicates that the larger the thixotropic recovery rate, the faster the system reconstructs the destroyed structure between particles after the stress is stopped, and the higher its stability. And a higher GOS concentration can promote the recovery of the destroyed structure of YFM. This is because the higher the GOS concentration, the stronger the viscoelasticity of YFM and the stronger the recovery ability to resist external force damage.

[0116] The %Recc of CM is 85.56%. When the concentration of GOS 7-G3A1_48 increases from 2.50 wt% to 4.50 wt%, the %Recc of YFM increases from 45.22% to 92.40%. And when the concentration of GOS 7-G3A1_48 is 4.00 wt%, the %Recc of YFM is 89.56%, which is close to the %Recc of CM. The texture characteristics of CM and YFM are shown in Table 4:

[0117] Table 4: Texture characteristics of CM and YFM

[0118]

[0119] By measuring the five indexes of hardness, cohesiveness, elasticity, adhesiveness and bonding strength of CM and YFM, the texture characteristics will affect the oral perception of mayonnaise by consumers, and hardness is the key factor affecting mayonnaise. As can be seen from Table 4, when the concentration of GOS 7-G3A1_48 increases from 2.50 wt% to 4.50 wt%, the hardness of YFM increases from 15.10 g to 18.05 g, and the bonding strength of YFM decreases from -9.17 to -10.02. When the concentration of GOS 7-G3A1_48 is 4.00 wt%, it is close to the hardness and bonding strength of CM. In terms of cohesiveness, elasticity and adhesiveness, there is little difference between YFM and CM.

[0120] It can be seen from this that YFM with a texture close to that of CM can be prepared with an appropriate concentration of GOS. Considering comprehensively, when the GOS particle concentration is 4.00 wt%, YFM is closest to CM in terms of texture state.

[0121] Stability of CM and YFM

[0122] Physical stability of CM and YFM: CM and YFM were placed in an incubator at 4 - 8 °C, and samples were taken at 0, 3, 7, and 14 d respectively to measure the mayonnaise particle size. The physical stability of CM and YFM was analyzed with the mayonnaise particle size as an index. The physical stability of CM and YFM is as Figure 14 shown. It can be Figure 14 seen that the change of d 4,3 of CM and YFM is not obvious, and with the increase of GOS concentration, the change trend of d 4,3 of YFM gradually decreases, indicating that both CM and YFM have good physical stability. This is because GOS irreversibly adsorbs on the oil - water interface and forms an interfacial adsorption layer, enhancing the interfacial stability of YFM, effectively preventing the coalescence of emulsion droplets, thus enhancing the stability of YFM; and the YFM prepared with GOS forms a dense gel network structure, which can effectively prevent the free movement of emulsion droplets, thus contributing to the long - term stability of the system and being beneficial to extending its shelf life.

[0123] The oxidative stability of CM and YFM is as Figure 15 shown. During the 14 - day storage and oxidation process, the POV values and TBARS values of CM and YFM both gradually increase with the extension of time; and within the same storage time, the POV values and TBARS values of YFM both gradually decrease with the increase of GOS concentration; when the GOS concentration reaches 4.00 wt% and above, and at the storage times of 3 d and 7 d, the POV value of YFM is close to that of CM, while at the storage time of 14 d, the POV value of YFM is less than that of CM; during the entire storage and oxidation process, the TBARS value of YFM is less than that of CM. It can be explained from this that GOS can be used as a natural antioxidant to improve the oxidative stability of YFM, and the effect of GOS in inhibiting oil oxidation is related to its concentration.

[0124] Thermal stability of CM and YFM: The freezing point temperature of an emulsion system is closely related to its freeze - thaw stability at low temperatures. Generally speaking, the lower the freezing point temperature, the stronger its freeze - thaw stability. Therefore, DSC was used to analyze the exothermic and endothermic behaviors of CM and YFM during the freeze - thaw process, and the freezing point temperatures of all mayonnaises were measured. The DSC curves and freezing point temperatures of CM and YFM are as Figure 16 shown. The peak temperature of the curve during the exothermic process represents the freezing point temperature. It can be seen from Figure 16It can be seen that when the GOS concentration is between 2.5 wt% and 3.5 wt%, the freezing point temperature of YFM is higher than that of CM. When the GOS concentration is 4.0 wt% and 4.5 wt%, the freezing point temperature of YFM is lower than that of CM, and the freezing point temperature of YFM gradually decreases with the increase of GOS concentration. The freezing point temperature of YFM is significantly affected by the GOS concentration. This is because the viscoelasticity of YFM increases with the increase of GOS concentration, resulting in emulsion droplets being tightly wrapped in the gel network structure, thus effectively inhibiting the formation of ice crystals.

[0125] The freeze-thaw stability of CM and YFM was tested by the method described in Example 2, and the test results are as Figure 17 shown. It can be Figure 17 seen that after being freeze-thawed three times, no obvious demulsification or oil separation occurred in YFM prepared from GOS, and it could still support the gel-like YFM, indicating its good freeze-thaw stability. However, after being freeze-thawed once, serious demulsification and two-phase separation occurred in CM, showing extremely poor freeze-thaw stability. It can be seen from this that YFM prepared from GOS has good stability and has the potential advantage of achieving high freeze-thaw stability and extending the shelf life without adding or adding a large amount of other cryoprotectants and food additives.

[0126] Sensory evaluation of CM and YFM

[0127] After storing the samples at room temperature for 1 day, 9 professionals engaged in food research were invited to conduct sensory evaluation on CM and YFM. Through visual inspection and tasting, the smoothness, color, flavor and odor of CM and YFM were evaluated using the double-blind method.

[0128] The visual appearance of CM and YFM is as Figure 18 shown. It can be Figure 18 seen that when the GOS 7-G3A1_48 concentration is 2.50 wt% and 3.00 wt%, the plasticity of YFM is poor and the structure collapses significantly. After standing for 1 h, the structure collapse is more obvious. When the GOS 7-G3A1_48 concentration is 3.50 wt%, there is little difference in appearance between 0 h and 1 h of standing. When the GOS 7-G3A1_48 concentration is 4.00 wt% and 4.50 wt%, YFM has good plasticity, no structure collapse, and after standing for 1 h, the structure shows no obvious change. The plasticity of CM is also good, but after standing for 1 h, not only does the structure collapse significantly, but also oil separates on the surface, indicating that the oxidation of CM exposed to air can lead to the separation of egg yolk sauce.

[0129] CM and YFM were further evaluated through sensory scoring. The smoothness of YFM increases with the increase of GOS concentration, and YFM 7-G3A1_48-4.00has the highest score. The smoothness of mayonnaise is mainly related to the particle size. The smaller the particle size, the finer its texture and the smoother its appearance. Although YFM 7-G3A1_48-4.50 has the smallest particle size, its smoothness score is relatively low because its concentration is too high. GOS 7-G3A1_48-4.50 cannot be completely adsorbed onto the oil-water interface, and some remaining GOS 7-G3A1_48-4.50 are dispersed in the aqueous phase, resulting in obvious granularity in YFM 7-G3A1_48-4.50 .

[0130] The flavor and smell of CM and YFM were scored. The scores of the flavor and smell of YFM increased with the increase in the GOS concentration, and YFM 7-G3A1_48-4.00 had the highest score. When the GOS concentration continued to increase, the scores of the flavor and smell of YFM decreased. This is because when the GOS concentration was low, the sour taste of YFM was significantly stronger, and increasing the GOS concentration could neutralize the sour taste to a certain extent, making its flavor more acceptable; however, when the GOS concentration was too high, a certain degree of bitterness and powdery texture would be produced, which was not beneficial to the flavor and aroma of YFM.

[0131] The color of CM and YFM was scored. The color score of YFM was greater than that of CM. It could be seen from the appearance that YFM presented milky white, while CM presented bright yellow, and milky white food was more likely to stimulate people's appetite.

[0132] In summary, YFM 7-G3A1_48-4.00 had better flavor and could be comparable to traditional CM.

[0133] The preparation method of the eggless mayonnaise provided by the present invention uses octenyl succinic anhydride-modified kudzu starch granules as an egg yolk substitute to prepare eggless mayonnaise, overcoming the stability and quality problems existing in the application of existing egg yolk substitutes in mayonnaise, and making the prepared eggless mayonnaise have better quality.

[0134] The above has made a detailed description of the implementation mode of the present invention, but the present invention is not limited to the described implementation mode. For those skilled in the art, various changes, modifications, substitutions, and variations made to these embodiments without departing from the principle and spirit of the present invention still fall within the protection scope of the present invention.

Claims

1. Application of OSA-modified kudzu starch in the preparation of eggless mayonnaise.

2. A method for preparing eggless mayonnaise, characterized in that, It includes the following steps: Step S1, preparing octenyl succinic anhydride-modified kudzu starch particles; Step S2, dissolving vinegar, salt, sugar, and the octenyl succinic anhydride-modified kudzu starch particles prepared in Step S1 in water, and homogenizing at 100,000 - 120,000 r / min for 1 - 2 min, where the mass concentration of the octenyl succinic anhydride-modified kudzu starch particles is 2.5 - 4.5%; Step S3, adding soybean oil with a volume fraction of 60% to the mixture in Step S2, and then homogenizing 2 - 3 times at 30 MPa to prepare eggless mayonnaise.

3. The method for preparing eggless mayonnaise according to claim 1, wherein In Step S2, the mass concentration of the octenyl succinic anhydride-modified kudzu starch particles is 4%.

4. The method for preparing eggless mayonnaise according to claim 1, characterized in that, In Step S1, preparing the octenyl succinic anhydride-modified kudzu starch particles includes the following steps: Step S11, preparing emulsified kudzu starch; Step S12, configuring the emulsified kudzu starch prepared in Step S11 into a starch aqueous dispersion; Step S13, adjusting the pH of the starch aqueous dispersion to 8 - 8.2, and then adding octenyl succinic anhydride with a volume concentration of 5 - 9%; Step S14, after the reaction, adjusting the system pH to 6 - 6.5, and obtaining octenyl succinic anhydride-modified kudzu starch particles after washing, drying, pulverizing, grinding, and sieving.

5. The method for preparing eggless mayonnaise according to claim 4, wherein In Step S11, the emulsified kudzu starch is prepared by a combined process of enzymatic hydrolysis and acid hydrolysis.

6. The method for preparing eggless mayonnaise according to claim 5, characterized in that, The preparation of the emulsified kudzu starch includes the following steps: Preparing a buffer solution with a pH of 4 - 5 using Na2HPO4 and citric acid, dispersing kudzu starch in the buffer solution, and sequentially adding glucoamylase and α-amylase to enzymatically hydrolyze the kudzu starch dispersion to obtain a hydrolyzate; Adjusting the pH of the hydrolyzate to neutral, and obtaining enzymatically pretreated kudzu starch after washing and drying; Adding an appropriate amount of sulfuric acid solution to the enzymatically pretreated kudzu starch, mixing evenly, and hydrolyzing at 40 - 45 °C for 24 - 48 h, and obtaining emulsified kudzu starch after centrifugation, washing, and freeze-drying.

7. The method for preparing eggless mayonnaise according to claim 6, characterized in that, During the enzymatic hydrolysis process, the total amount of enzymes accounts for 2 - 3% of the total amount of kudzu starch.

8. The method for preparing eggless mayonnaise according to claim 7, characterized in that, The ratio of glucoamylase to α-amylase is 3:

1.

9. The method for preparing eggless mayonnaise according to claim 6, characterized in that, The added mass of the sulfuric acid solution is 14.3% of the mass of the enzymatically pretreated kudzu starch, and the concentration of the sulfuric acid solution is 3.16 mol / L.

10. The preparation method of the eggless mayonnaise according to claim 4, characterized in that, In Step S13, the volume concentration of octenyl succinic anhydride is 7%.

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