Low-oil-loss plastic fat low in saturated fatty acids, and low-temperature preparation method therefor

Abstract

A low-oil-loss plastic fat which is low in saturated fatty acids, and a low-temperature preparation method therefor. The method comprises: dispersing OSA starch in an aqueous solution and stirring, to obtain an OSA starch aqueous solution; dispersing chitosan in an acetic acid aqueous solution and stirring, to obtain a chitosan solution; mixing the obtained OSA starch aqueous solution with the chitosan solution, adjusting the pH to 5.5-6.5 and stirring, to obtain an OSA starch-chitosan electrostatic complex; mixing and stirring the obtained OSA starch-chitosan electrostatic complex with soybean oil, to obtain an oil-in-water emulsion, then drying until the water is removed, to obtain a solid lipid; subjecting the obtained solid lipid to high-speed shearing, to form an oil gel. The oil gel can be applied in the food field.

Description

Low oil loss plastic fat with low saturated fatty acid and low-temperature preparation method thereof TECHNICAL FIELD

[0001] The present application relates to the field of food processing, and discloses a low oil loss plastic fat with low saturated fatty acid and a low-temperature preparation method thereof. BACKGROUND

[0002] At present, the oil and fat special for food, such as hydrogenated oil, palm oil, animal fat and the like, has a plastic texture, and most of the lipids contain excessive saturated or trans fatty acids. Studies have shown that long-term use of such fats can cause atherosclerosis, increase the content of high-density lipoprotein, and cause cardiovascular and cerebrovascular diseases. Oil gelation is a very potential manufacturing technology that can replace traditional fats, and through the use of oil gel agents, a stable three-dimensional network is formed in the oil, and liquid oil is converted into a gel-like substance without changing its chemical properties.

[0003] From the perspective of colloids, the formation of natural fats comes from the crystallization of high-melting-point triglycerides, so that low-melting-point liquid triglycerides can be physically captured. Therefore, liquid oil gelation is designed on the basis of mimicking structure and semi-solid rheological behavior, and is widely used in the baking, dairy, and meat industries. However, the traditional oil gel construction technology is to directly disperse oil-soluble small molecule gel agents (waxes, glycerides, fatty acids and their derivatives) into the oil phase at a temperature higher than the melting point of the gel agent, and then cooled to a lower temperature under mild conditions to form an oil gel. However, in this case, a high temperature and a high concentration of gel agents are required, which is not allowed by food health requirements. Therefore, it is necessary to prepare a healthy edible oil gel agent for low-temperature construction of high-stability and plasticity oil gel.

[0004] SUMMARY

[0005] In order to solve the problems existing in the prior art, the present application uses an edible OSA starch and chitosan electrostatic complex as an oil gel agent, and uses liquid soybean oil with low saturated fatty acid content as an oil base, to construct a plastic fat with an oil phase ratio of up to 95% by an emulsion template method, and the process involves a temperature lower than 45℃.

[0006] The present application provides a low saturated fatty acid low oil loss plastic fat, which is prepared by mixing and stirring an OSA starch-chitosan electrostatic complex solution and soybean oil, and then drying to remove water and high-speed shearing.

[0007] Further, the OSA starch-chitosan electrostatic complex solution is prepared by mixing an OSA starch aqueous solution and a chitosan solution.

[0008] Further, the concentration of the OSA starch aqueous solution is 0.08-0.1 g / mL.

[0009] Further, the concentration of the chitosan solution is 0.002-0.02 g / mL.

[0010] Preferably, the concentration of the chitosan solution is 0.01-0.02 g / mL.

[0011] Further, the mass ratio of the OSA starch and the chitosan is 1:0.025-0.25.

[0012] Preferably, the mass ratio of the OSA starch and the chitosan is 1:0.125-0.25.

[0013] Further, the mass ratio of the OSA starch-chitosan electrostatic complex solution and the soybean oil is 0.8-1.2:1.

[0014] Further, the mass ratio of the OSA starch-chitosan electrostatic complex and the soybean oil is 0.82-1:20.

[0015] Preferably, the mass ratio of the OSA starch-chitosan electrostatic complex and the soybean oil is 0.9-1:20.

[0016] The present application provides a method for preparing a low-saturated fatty acid low-oil loss plastic fat at low temperature, comprising the following steps:

[0017] Step 1: dispersing OSA starch in an aqueous solution to obtain an OSA starch aqueous solution;

[0018] Step 2: dispersing chitosan in an aqueous acetic acid solution to obtain a chitosan solution;

[0019] Step 3: mixing the OSA starch aqueous solution obtained in Step 1 and the chitosan solution obtained in Step 2, adjusting the pH to 5.5-6.5, and stirring to obtain an OSA starch-chitosan electrostatic complex solution;

[0020] Step 4: mixing the OSA starch-chitosan electrostatic complex solution obtained in Step 3 with soybean oil and stirring to obtain an oil-in-water emulsion, and then drying until the water is removed to obtain a solid lipid;

[0021] Step 5: high-speed shearing the solid lipid obtained in Step 4 to form an oil gel.

[0022] Further, the stirring in Step 1 is stirring at 400-600 r / min for 2-6 h.

[0023] Further, the concentration of the OSA starch in the OSA starch aqueous solution in Step 1 is 0.08-0.1 g / mL.

[0024] Further, the stirring in step 2 is at 35-40℃, at 400-600r / min for 12-16h.

[0025] Further, the concentration of acetic acid in the acetic acid aqueous solution in step 2 is 1-2%.

[0026] Further, the concentration of chitosan in the chitosan solution in step 2 is 0.002-0.02g / mL.

[0027] Preferably, the concentration of chitosan in the chitosan solution in step 2 is 0.01-0.02g / mL.

[0028] Further, the volume ratio of the OSA starch aqueous solution and the chitosan solution in step 3 is 0.8-1:1.

[0029] Further, the stirring in step 3 is at 400-600r / min for 2-6h.

[0030] Further, the mass ratio of the OSA starch-chitosan electrostatic complex solution and the soybean oil in step 4 is 0.8-1.2:1.

[0031] Further, the stirring in step 4 is at 8000-12000rmp for 2-5min.

[0032] Further, the temperature for drying in step 4 is 40-45℃.

[0033] Further, the high-speed shearing in step 4 is at 8000-12000rmp for 1-5min.

[0034] The present application provides a low-saturated fatty acid low-oil loss plastic fat prepared according to the above method.

[0035] The present application provides the application of the low-saturated fatty acid low-oil loss plastic fat in the field of food.

[0036] The present application also provides a method for preparing bread using the low-saturated fatty acid low-oil loss plastic fat, comprising the following steps:

[0037] (1) 100-150 parts of high-gluten flour, 50-60 parts of eggs, 2-5 parts of salt, 10-15 parts of sugar, 2-5 parts of yeast and 5-10 parts of oil gel are weighed according to the mass fraction;

[0038] (2) the weighed flour, eggs, salt, sugar and yeast are mixed, 20-50 parts of milk and 50-100 parts of water are added, and the oil gel is added, and a smooth dough is kneaded;

[0039] (3) The kneaded dough is rested for 10-15 minutes, then is put into a mold, and is rested for a period of time before being baked to obtain the bread.

[0040] The application further provides a method for preparing shrimp cakes by using low-saturation fatty acid low-oil-loss plastic fat, comprising the following steps:

[0041] (1) 100-150 parts of shrimp paste are weighed according to the mass fraction, then 5-10 parts of oil gel are added to the shrimp paste for chopping and mixing, 1-3 parts of salt are further added for chopping and mixing, finally 1-3 parts of monosodium glutamate, 5-10 parts of starch and 5-10 parts of chicken broth are added for chopping and mixing;

[0042] (2) The chopped shrimp paste is put into a mold, then is heated by steam to obtain the shrimp cake. Beneficial effects

[0043] 1. The oil gel agent prepared by the electrostatic interaction of OSA starch-chitosan can make the prepared edible oil gel have a high oil phase ratio (95.24-96.15%) and good oil stability, low oil loss of oil gel, good recovery and the like, and is suitable for replacing oil in the food field.

[0044] 2. The oil gel can be prepared at a temperature lower than 45 DEG C, so that various harmful substances generated by high-temperature oil in the preparation process can be avoided, and low temperature can also alleviate the oxidation and deterioration of oil, thereby prolonging the shelf life of the oil gel. BRIEF DESCRIPTION OF DRAWINGS

[0045] Fig. 1: Zeta potential value of the oil gel agent of Comparative Example 1 and Examples 1-3.

[0046] Fig. 2: Emulsion particle size of Comparative Examples 1-2 and Examples 1-3.

[0047] Fig. 3: Oil gel morphology of Comparative Examples 1-2 and Examples 1-3.

[0048] Fig. 4: Microstructure of the oil gel of Comparative Examples 1-2 and Examples 1-3.

[0049] Fig. 5: Oil holding capacity of the oil gel of Comparative Examples 1-2 and Examples 1-3.

[0050] Fig. 6: Rheological properties of the oil gel of Comparative Examples 1-2 and Examples 1-3.

[0051] Fig. 7: Oil gel morphology of Comparative Examples 3-4.

[0052] Fig. 8: Oil holding capacity of the oil gel of Comparative Examples 3-4 and Example 2.

[0053] Fig. 9: Rheological properties of the oil gel of Comparative Examples 3-4 and Example 2.

[0054] Figure 10: Oil gel morphology of Comparative Example 5-6.

[0055] Figure 11: Oil holding capacity of oil gels of Comparative Example 5-6 and Example 2.

[0056] Figure 12: Rheological properties of oil gels of Comparative Example 5-6 and Example 2.

[0057] Figure 13: Oil gel morphology of Comparative Example 7-8.

[0058] Figure 14: Oil holding capacity of oil gels of Comparative Example 7-8 and Examples 1 and 3. DETAILED DESCRIPTION

[0059] The present application will be described in detail below with reference to the accompanying drawings and examples.

[0060] Raw material sources

[0061] Octenyl succinic anhydride starch (OSA starch) was purchased from Hangzhou Prostar Starch Co., Ltd., and chitosan was purchased from Aladdin Reagent Co., Ltd.

[0062] Corn starch nanoparticle preparation method: 10 g of corn starch was dispersed in 100 mL of deionized water to obtain a starch suspension. Then a starch paste was formed by boiling and stirring for one hour. The container containing the starch paste was transferred to a constant temperature water bath at 58°C, 1.5 mL of pullulanase (2000 U) solution was added, and incubated for 24 h. Then the mixture was placed in a boiling water bath for one hour to inactivate the enzyme. The sample was centrifuged at 4000 r / min for 1 min, and the precipitate and unhydrolyzed starch were removed. Then the supernatant was collected, mixed with an equal volume of hot ethanol, and then centrifuged at 4000 r / min for 1 min. The above operation was repeated 3 times after removing the precipitate. The final supernatant was freeze-dried to obtain corn starch nanoparticles.

[0063] Laurylic acid modified starch preparation method: 10 g of corn starch was dispersed in 15 mL of deionized water to form a starch suspension. Then 0.6 g of laurylic acid and 0.01 mL of hydrochloric acid were dissolved in a 45°C ethanol solution, which was placed in a microwave reactor and reacted at a power of 600 W for 15 min. Finally, the reaction was washed with hot ethanol 3 times and dried at 45°C until the moisture was completely removed to obtain laurylic acid modified starch.

[0064] Example 1

[0065] Step 1: 0.8 g of OSA starch was dispersed in 10 mL of aqueous solution and stirred at a stirring speed of 600 r / min for 4 h to obtain an OSA starch aqueous solution.

[0066] Step 2: 0.02 g of chitosan was dispersed in 10 mL of 1% acetic acid solution, and stirred at 600 r / min for 12 h at 40 °C until completely dissolved to obtain a chitosan solution.

[0067] Step 3: The solutions obtained in steps 1 and 2 were mixed in equal volumes, and the pH was adjusted to 6, and stirred at 600 r / min for 4 h to obtain an OSA starch-chitosan electrostatic complex solution.

[0068] Step 4: The OSA starch-chitosan electrostatic complex solution obtained in step 3 was mixed with 20 g of soybean oil, and a 50% oil-in-water emulsion was obtained by high-speed stirring at 12000 rmp for 3 min using a stator-rotor disperser, and poured into a culture dish, and dried in an oven at 45 °C until the water was removed to obtain a solid lipid.

[0069] Step 5: The solid lipid obtained in step 4 was sheared at high speed at 10000 rmp for 1 min at room temperature to form an oil gel, and the solid content of the obtained oil gel was 3.94%.

[0070] Example 2

[0071] Step 1: 0.8 g of OSA starch was dispersed in 10 mL of water solution, and stirred at 600 r / min for 4 h to obtain an OSA starch aqueous solution.

[0072] Step 2: 0.1 g of chitosan was dispersed in 10 mL of 1% acetic acid solution, and stirred at 600 r / min for 12 h at 40 °C until completely dissolved to obtain a chitosan solution.

[0073] Step 3: The solutions obtained in steps 1 and 2 were mixed in equal volumes, and the pH was adjusted to 6, and stirred at 600 r / min for 4 h to obtain an OSA starch-chitosan electrostatic complex solution.

[0074] Step 4: The OSA starch-chitosan electrostatic complex solution obtained in step 3 was mixed with 20 g of soybean oil, and a 50% oil-in-water emulsion was obtained by high-speed stirring at 12000 rmp for 3 min using a stator-rotor disperser, and poured into a culture dish, and dried in an oven at 45 °C until the water was removed to obtain a solid lipid.

[0075] Step 5: The solid lipid obtained in step 4 was sheared at high speed at 10000 rmp for 1 min at room temperature to form an oil gel, and the solid content of the obtained oil gel was 4.31%.

[0076] Example 3

[0077] Step 1: 0.8 g of OSA starch was dispersed in 10 mL of water solution and stirred at a stirring speed of 600 r / min for 4 h to obtain an OSA starch water solution.

[0078] Step 2: 0.2 g of chitosan was dispersed in 10 mL of acetic acid solution with a concentration of 1%, and stirred at a temperature of 40°C, a stirring speed of 600 r / min, and a stirring time of 12 h until completely dissolved to obtain a chitosan solution.

[0079] Step 3: The solutions obtained in steps 1 and 2 were mixed in equal volumes, and the pH was adjusted to 6, and stirred at a stirring speed of 600 r / min for 4 h to obtain an OSA starch-chitosan electrostatic complex solution.

[0080] Step 4: The OSA starch-chitosan electrostatic complex solution obtained in step 3 was mixed with 20 g of soybean oil, and a stator-rotor disperser was used to stir at a high speed of 12000 rmp for 3 min to obtain a 50% oil-in-water emulsion, which was poured into a culture dish and dried in an oven at 45°C until the water was removed to obtain a solid lipid.

[0081] Step 5: The solid lipid obtained in step 4 was sheared at a high speed of 10000 rmp for 1 min at room temperature to form an oil gel, and the solid content of the obtained oil gel was 4.76%.

[0082] Comparative Example 1

[0083] Step 1: 0.4 g of OSA starch was dispersed in 20 mL of water solution and stirred at a stirring speed of 600 r / min for 4 h to obtain an OSA starch water solution.

[0084] Step 2: The OSA starch-chitosan electrostatic complex solution obtained in step 1 was mixed with 20 g of soybean oil, and a stator-rotor disperser was used to stir at a high speed of 12000 rmp for 3 min to obtain a 50% oil-in-water emulsion, which was poured into a culture dish and dried in an oven at 45°C until the water was removed to obtain a solid lipid.

[0085] Step 3: The solid lipid obtained in step 2 was sheared at a high speed of 10000 rmp for 1 min at room temperature to form an oil gel, and the solid content of the obtained oil gel was 3.85%.

[0086] Comparative Example 2

[0087] Step 1: 0.5 g of OSA starch was dispersed in 20 mL of water solution and stirred at a stirring speed of 600 r / min for 4 h to obtain an OSA starch water solution.

[0088] Step 2: The OSA starch-chitosan electrostatic complex solution obtained in step 1 was mixed with 20 g of soybean oil, and a 50% oil-in-water emulsion was obtained by stirring at 12000 rpm for 3 min using a stator-rotor disperser, and then poured into a petri dish and dried in an oven at 45°C until the water was removed to obtain a solid lipid.

[0089] Step 3: The solid lipid obtained in step 2 was sheared at 10000 rpm for 1 min at room temperature to form an oil gel, and the solid content of the obtained oil gel was 4.76%.

[0090] Performance determination

[0091] (1) Measurement of zeta potential:

[0092] The OSA starch solution prepared in step 1 and the OSA starch-chitosan complex prepared in step 3 in Examples 1-3 and Comparative Example 1 were diluted 10 times, and a chitosan solution with a mass concentration of 0.5% was prepared, and then measured using a laser nanoparticle size analyzer.

[0093] Figure 1 shows the zeta potential values of the oil gels in Examples 1-3 and Comparative Example 1, and it can be seen that the addition of chitosan changes the negative zeta potential value of OSA starch (-7.34 mV) to a positive zeta potential value (+10.6-25.9 mV), and the zeta potential value is positively correlated with the concentration of chitosan. This indicates that electrostatic interaction occurs between OSA starch and chitosan.

[0094] (2) Measurement of emulsion particle size:

[0095] The size of the droplets in the oil-in-water emulsion obtained in step 4 was characterized using a laser diffraction particle size analyzer. Before the droplet size analysis, 1 g of the oil-in-water emulsion was dispersed in 10 mL of distilled water by vortex oscillation. The D[4,3] (volume-weighted mean diameter) of the droplets was calculated according to the particle size distribution. Each sample was measured three times to obtain an average value.

[0096] Figure 2 shows the average particle size of the emulsion droplets in Examples 1-3 and Comparative Examples 1-2, and it can be seen that the average particle size of the emulsion droplets in Examples 1-3 (9.38-14.07 μm) is lower than that in Comparative Examples 1-2 (17.49-20.25 μm). This indicates that the OSA starch-chitosan electrostatic complex has stronger emulsifying ability.

[0097] (3) Measurement of morphology and microstructure:

[0098] Morphology was determined by taking pictures of the samples with a camera under suitable light. Before microstructure test, oil phase (soybean oil) and oil gel agent (OSA starch-chitosan electrostatic complex) were labeled with Nile red (0.1%, excitation 488 nm) and FITC (0.1%, excitation 561 nm) respectively, and the images of samples were recorded using a digital camera attached to a laser confocal microscope.

[0099] Figure 3 shows the morphology of oil gels in Examples 1-3 and Comparative Examples 1-2. It can be seen that the oil gels in Examples 1-3 all maintained smooth surface structure after shearing. However, the oil gels from Comparative Examples 1-2 showed shrinkage, oil leakage and liquid oil spontaneously separated after shearing. The microstructure of oil gels in Examples 1-3 and Comparative Examples 1-2 taken by laser confocal microscope is shown in Figure 4. The oil droplets in Examples 1-3 were round and small, and closely aggregated. However, the oil droplets in Comparative Examples 1-2 were large and irregularly shaped. This indicates that OSA starch-chitosan electrostatic complex can form a stable interface layer on the surface of oil droplets, thereby achieving the fixation of oil droplets.

[0100] (4) Measurement of oil loss:

[0101] The oil gels prepared in Examples and Comparative Examples were weighed and loaded into centrifuge tubes, and centrifuged at 4000 rpm for 10 minutes. The percentage of separated oil in the total mass before centrifugation was calculated.

[0102] Figure 5 shows the oil loss of oil gels in Examples 1-3 and Comparative Examples 1-2. It can be seen that the oil loss of oil gels in Examples 1-3 after centrifugation was between 1.52-9.19%, and was negatively correlated with the concentration of chitosan. However, the oil loss of oil gels in Comparative Examples 1-2 was between 10.28-14.09%. This indicates that OSA starch-chitosan electrostatic complex is a very effective oil gel agent, which can effectively maintain the morphology of oil gels and reduce oil loss.

[0103] (5) Measurement of rheology:

[0104] The rheological properties of oil gels were analyzed using a TA rotary rheometer. The clamp was selected as an aluminum flat plate with a diameter of 40 mm, and the test gap was 1 mm. The oil gel sample was evenly coated between the upper and lower clamps of the rheometer, and the excess sample was removed along the edge of the clamp. The frequency scan was performed in the range of 0.1-100 rad / s, and the strain was 0.1%. The values of G' and G" were recorded during the entire test process. Thixotropy was tested using a time sweep test with an interval of 300 s and an alternating shear rate of 0.1 s-1 and 10 s-1.

[0105] Fig. 6 and Table 1 show the rheological properties of the oil gels in Examples 1-3 and Comparative Examples 1-2. It can be seen that the critical crosslinking points of the oil gels in Examples 1-3 are between 10.57-11.92%, which are higher than those of the oil gels in Comparative Example 1-2 (7.84-8.10%). This indicates that a more robust interfacial film can be formed on the surface of the oil droplets by the OSA starch-chitosan complex, thereby showing greater resistance to deformation. In addition, the viscoelasticity of the oil gels in Examples 1-3 is several orders of magnitude higher than that of the oil gels in Comparative Example 1-2. This indicates that the thick interfacial layer formed by the OSA starch-chitosan complex avoids the destruction of the oil droplets during dehydration, thereby increasing the tightness between the oil droplets and thus increasing the viscoelasticity of the system. Thixotropy also indicates that the shear recovery rate of the oil gels in Examples 1-3 is between 76.81-91.1%, which is higher than that of the oil gels in Comparative Example 1-2 (38.54-56.77%). This result indicates that the electrostatic complex formed between OSA starch and chitosan plays a crucial role in determining the structural recovery of the oil gels during shearing.

[0106] Table 1 Critical crosslinking points and recovery rates of the oil gels in Comparative Example 1-2 and Examples 1-3

[0107] Comparative Example 3

[0108] The oil gel was prepared according to the procedure of Example 2, with only the OSA starch replaced by corn starch nanoparticles, and the other steps and parameters unchanged. The solid content of the obtained oil gel was 4.31%.

[0109] The specific process is as follows:

[0110] Step 1: 0.8 g of corn starch nanoparticles was dispersed in 10 mL of aqueous solution, and stirred at a stirring speed of 600 r / min for 4 h to obtain a corn starch nanoparticle aqueous solution.

[0111] Step 2: 0.1 g of chitosan was dispersed in 10 mL of 1% acetic acid solution, and stirred at a temperature of 40°C, a stirring speed of 600 r / min and a stirring time of 12 h until complete dissolution to obtain a chitosan solution.

[0112] Step 3: The solutions obtained in Steps 1 and 2 were mixed in equal volumes, and the pH was adjusted to 6, and stirred at a stirring speed of 600 r / min for 4 h to obtain a corn starch-chitosan electrostatic complex solution.

[0113] Step 4: The corn starch-chitosan electrostatic complex solution obtained in step 3 was mixed with 20 g of soybean oil, and a 50% oil-in-water emulsion was obtained by stirring at a high speed of 12000 rpm for 3 min using a stator-rotor disperser, and then poured into a culture dish and dried in an oven at 45°C until the water was removed to obtain a solid lipid.

[0114] Step 5: The solid lipid obtained in step 4 was sheared at a high speed of 10000 rpm for 1 min at room temperature to form an oil gel, and the solid content of the obtained oil gel was 4.31%.

[0115] Comparative Example 4

[0116] Referring to the steps of Example 2, only the OSA starch was replaced with lauric acid modified starch, and the other steps and parameters were unchanged, to prepare an oil gel, and the solid content of the obtained oil gel was 4.31%.

[0117] The specific process is as follows:

[0118] Step 1: 0.8 g of lauric acid modified starch was dispersed in 10 mL of an aqueous solution and stirred at a stirring speed of 600 r / min for 4 h to obtain a lauric acid modified starch aqueous solution.

[0119] Step 2: 0.1 g of chitosan was dispersed in 10 mL of an acetic acid solution with a concentration of 1%, and stirred at a temperature of 40°C, a stirring speed of 600 r / min, and for a stirring time of 12 h until completely dissolved to obtain a chitosan solution.

[0120] Step 3: The solutions obtained in steps 1 and 2 were mixed in equal amounts, and the pH was adjusted to 6, and stirred at a stirring speed of 600 r / min for 4 h to obtain a lauric acid modified starch-chitosan electrostatic complex solution.

[0121] Step 4: The lauric acid modified starch-chitosan electrostatic complex solution obtained in step 3 was mixed with 20 g of soybean oil, and a 50% oil-in-water emulsion was obtained by stirring at a high speed of 12000 rpm for 3 min using a stator-rotor disperser, and then poured into a culture dish and dried in an oven at 45°C until the water was removed to obtain a solid lipid.

[0122] Step 5: The solid lipid obtained in step 4 was sheared at a high speed of 10000 rpm for 1 min at room temperature to form an oil gel, and the solid content of the obtained oil gel was 4.31%.

[0123] The oil gels prepared in Comparative Examples 3-4 and Example 2 were subjected to performance determination, and the results are shown in Figures 7-9.

[0124] It can be found that the oil gels obtained from corn starch nanoparticles and lauric acid modified starch have obvious floating oil on the surface (Figure 7), and the oil gel prepared by the nanometer starch particles is the most obvious. The oil loss results show that the stability of the oil gels prepared by Comparative Examples 3 and 4 is lower than that of the oil gel prepared by OSA starch (Figure 8). Rheological results also show that the viscoelasticity of the oil gel prepared by OSA starch is higher than that of corn starch nanoparticles and lauric acid modified starch (Figure 9).

[0125] Comparative Example 5

[0126] Referring to the steps of Example 2, only replace chitosan with xanthan gum, and other steps and parameters remain unchanged, prepare oil gel, and the solid content of the obtained oil gel is 4.31%.

[0127] The specific process is as follows:

[0128] Step 1: 0.8g OSA starch is dispersed in 10mL aqueous solution, stirred at a stirring speed of 600r / min for 4h, and OSA starch aqueous solution is obtained.

[0129] Step 2: 0.1g xanthan gum is dispersed in 10mL aqueous solution, stirred at a temperature of 40℃, a stirring speed of 600r / min, and a stirring time of 12h until completely dissolved, and xanthan gum solution is obtained.

[0130] Step 3: The solutions obtained in steps 1 and 2 are mixed in equal volume, and the pH is adjusted to 6, and stirred at a stirring speed of 600r / min for 4h to obtain OSA starch-xanthan gum electrostatic complex solution.

[0131] Step 4: The OSA starch-xanthan gum electrostatic complex solution obtained in step 3 is mixed with 20g soybean oil, and a stator-rotor disperser is used to stir at a high speed of 12000rmp for 3min to obtain 50% oil-in-water emulsion, and then poured into a culture dish and dried in an oven at 45℃ until the water is removed to obtain solid lipid.

[0132] Step 5: The solid lipid obtained in step 4 is sheared at a high speed of 10000rmp for 1min at room temperature to form an oil gel, and the solid content of the obtained oil gel is 4.31%.

[0133] Comparative Example 6

[0134] Referring to the steps of Example 2, only replace chitosan with guar gum, and other steps and parameters remain unchanged, prepare oil gel, and the solid content of the obtained oil gel is 4.31%.

[0135] The specific process is as follows:

[0136] Step 1: 0.8 g of OSA starch was dispersed in 10 mL of water solution and stirred at a speed of 600 r / min for 4 h to obtain an OSA starch water solution.

[0137] Step 2: 0.1 g of guar gum was dispersed in 10 mL of water solution, and stirred at a temperature of 40°C, a speed of 600 r / min for 12 h until completely dissolved to obtain a guar gum solution.

[0138] Step 3: The solutions obtained in steps 1 and 2 were mixed in equal volumes, and the pH was adjusted to 6, and stirred at a speed of 600 r / min for 4 h to obtain an OSA starch-guar gum electrostatic complex solution.

[0139] Step 4: The OSA starch-guar gum electrostatic complex solution obtained in step 3 was mixed with 20 g of soybean oil, and a stator-rotor disperser was used to stir at a high speed of 12000 rmp for 3 min to obtain a 50% oil-in-water emulsion, which was poured into a petri dish and dried in an oven at 45°C until the water was removed to obtain a solid lipid.

[0140] Step 5: The solid lipid obtained in step 4 was sheared at a high speed of 10000 rmp for 1 min at room temperature to form an oil gel, and the solid content of the obtained oil gel was 4.31%.

[0141] The oil gels prepared in Comparative Examples 5-6 and Example 2 were subjected to performance testing, and the results are shown in FIGS. 10-12.

[0142] It can be found that both OSA starch-xanthan gum and OSA starch-guar gum can form oil gels, and there is almost no oil floating on the surface (FIG. 10). It is worth noting that the oil retention stability and viscoelasticity of the oil gels prepared in Comparative Example 5 and Comparative Example 6 are lower than those of the OSA starch-chitosan oil gel (FIGS. 11 and 12). This result proves that OSA starch-chitosan is the optimal combination for preparing an oil gel.

[0143] Comparative Example 7

[0144] Referring to the steps of Example 1, only the amount of chitosan in step 2 was adjusted to 0.01 g, and the other steps and parameters were unchanged to prepare an oil gel, and the solid content of the obtained oil gel was 3.89%.

[0145] The specific process is as follows:

[0146] Step 1: 0.8 g of OSA starch was dispersed in 10 mL of water solution and stirred at a speed of 600 r / min for 4 h to obtain an OSA starch water solution.

[0147] Step 2: 0.01 g of chitosan was dispersed in 10 mL of 1% acetic acid solution, and stirred at 600 r / min for 12 h at 40 °C until completely dissolved to obtain a chitosan solution.

[0148] Step 3: The solutions obtained in steps 1 and 2 were mixed in equal volumes, and the pH was adjusted to 6, and stirred at 600 r / min for 4 h to obtain an OSA starch-chitosan electrostatic complex solution.

[0149] Step 4: The OSA starch-chitosan electrostatic complex solution obtained in step 3 was mixed with 20 g of soybean oil, and a 50% oil-in-water emulsion was obtained by high-speed stirring at 12000 rpm for 3 min using a stator-rotor disperser, and poured into a culture dish, and dried in an oven at 45 °C until the water was removed to obtain a solid lipid.

[0150] Step 5: The solid lipid obtained in step 4 was sheared at room temperature at 10000 rpm for 1 min to form an oil gel, and the solid content of the obtained oil gel was 3.89%.

[0151] Comparative Example 8

[0152] The oil gel was prepared according to the steps of Example 1, except that the amount of chitosan in step 2 was adjusted to 0.26 g, and other steps and parameters were unchanged, and the solid content of the obtained oil gel was 5.03%.

[0153] The specific process is as follows:

[0154] Step 1: 0.8 g of OSA starch was dispersed in 10 mL of water solution, and stirred at 600 r / min for 4 h to obtain an OSA starch aqueous solution.

[0155] Step 2: 0.26 g of chitosan was dispersed in 10 mL of 1% acetic acid solution, and stirred at 600 r / min for 12 h at 40 °C until completely dissolved to obtain a chitosan solution.

[0156] Step 3: The solutions obtained in steps 1 and 2 were mixed in equal volumes, and the pH was adjusted to 6, and stirred at 600 r / min for 4 h to obtain an OSA starch-chitosan electrostatic complex solution.

[0157] Step 4: The OSA starch-chitosan electrostatic complex solution obtained in step 3 was mixed with 20 g of soybean oil, and a 50% oil-in-water emulsion was obtained by high-speed stirring at 12000 rpm for 3 min using a stator-rotor disperser, and poured into a culture dish, and dried in an oven at 45 °C until the water was removed to obtain a solid lipid.

[0158] Step 5: The solid lipid obtained in step 4 was sheared at a high speed of 10000 rpm for 1 min at room temperature to form an oil gel, and the solid content of the obtained oil gel was 5.03%.

[0159] The oil gels prepared from Comparative Examples 7-8 were subjected to performance tests, and the results are shown in Figures 13-14. It can be found that when the mass of added chitosan is reduced to 0.01 g, there is a slight oil slick on the surface of the oil gel, and when the mass of added chitosan is increased to 0.26 g, there is a large amount of oil slick on the surface of the oil gel (Figure 13). And the oil loss results show that the stability of the oil gel prepared when the chitosan concentration is too low or too high is not good. It can be concluded that when the mass of chitosan is 0.02-0.2 g, the performance of the oil gel is the best (Figure 14).

[0160] Application Example 1

[0161] The oil gels prepared in Examples 1-3 of the present application have high stability, and their elastic modulus and viscosity values are similar to those of commercial bakery shortening, so the oil gels can be used as shortening and have wide application potential in baked bread, biscuits and other products.

[0162] A method for preparing bread using an oil gel, the operation of which is as follows:

[0163] (1) Prepare 100 g of high-gluten flour, 50 g of egg (1), 2 g of salt, 10 g of sugar, 2 g of yeast and 5 g of oil gel;

[0164] (2) Mix the flour, egg, salt, sugar and yeast, add an appropriate amount of milk and water, and then add the oil gel, and knead the dough into a smooth dough;

[0165] (3) Let the kneaded dough rest for 10-15 minutes, then cut the rested dough into small doughs, let them stand for a period of time, shape them and then put them into a mold, let them rest for a period of time, and then put the mold into a preheated oven and bake at an appropriate temperature and time.

[0166] Application Example 2

[0167] The oil gel of the present application can replace animal fat for food processing, such as using the oil gel in the preparation of shrimp cakes, fish cakes and the like and reducing the amount of lard originally used, so that the processed food is healthier without weakening the quality of the food.

[0168] A method for preparing shrimp cakes using an oil gel, the operation of which is as follows:

[0169] (1) Prepare 100 g of shrimp paste, then add 5 g of oil gel to the shrimp paste and chop, then add 1 g of salt and continue to chop, and finally add an appropriate amount of monosodium glutamate, 5 g of starch and 5 g of chicken juice and continue to chop.

[0170] (2) The chopped shrimp paste is put into a mold, and then steam heating is performed to obtain shrimp cakes.

[0171] The above provided examples are not intended to limit the scope of the present application, and the described steps are not intended to limit the order of execution. Those skilled in the art can make obvious improvements to the present application based on the existing common knowledge, which also falls within the protection scope defined by the claims of the present application.

Claims

1. A low-saturated fatty acid, low-oil-loss plastic fat, characterized in that, The low-oil-loss plastic fat with low saturated fatty acids is obtained by mixing and stirring an OSA starch-chitosan electrostatic complex solution with soybean oil, then drying to remove moisture and performing high-speed shearing; the OSA starch-chitosan electrostatic complex solution is obtained by mixing an OSA starch aqueous solution and a chitosan solution.

2. The low-oil-loss plastic fat according to claim 1, characterized in that, The concentration of OSA starch aqueous solution is 0.08–0.1 g / mL; the concentration of chitosan solution is 0.002–0.02 g / mL.

3. The low-oil-loss plastic fat according to claim 1, characterized in that, The mass ratio of OSA starch to chitosan in the OSA starch-chitosan electrostatic complex solution is 1:0.125 to 0.

25.

4. The low-oil-loss plastic fat according to claim 1, characterized in that, The mass ratio of OSA starch-chitosan electrostatic complex solution to soybean oil is 0.8–1.2:

1.

5. A method for preparing low-oil-loss plastic fat according to any one of claims 1 to 4 at low temperature, characterized in that, Includes the following steps: Step 1: Disperse OSA starch in an aqueous solution and stir to obtain an OSA starch aqueous solution; Step 2: Disperse chitosan in an aqueous acetic acid solution and stir to obtain a chitosan solution; Step 3: Mix the OSA starch aqueous solution obtained in Step 1 and the chitosan solution obtained in Step 2, adjust the pH to 5.5-6.5, and stir to obtain an OSA starch-chitosan electrostatic complex solution; Step 4: Mix the OSA starch-chitosan electrostatic complex solution obtained in Step 3 with soybean oil to obtain an oil-in-water emulsion, and then dry it until the water is removed to obtain solid lipids. Step 5: The solid lipids obtained in Step 4 are subjected to high-speed shearing to form an oleogel.

6. The method according to claim 5, characterized in that, In step 1, the stirring is carried out at 400-600 r / min for 2-6 hours.

7. The method according to claim 5, characterized in that, In step 1, the concentration of OSA starch in the OSA starch aqueous solution is 0.08–0.1 g / mL.

8. The method according to claim 5, characterized in that, In step 2, the stirring is carried out at 35–40°C and 400–600 r / min for 12–16 hours.

9. The method according to claim 5, characterized in that, In step 2, the concentration of acetic acid in the aqueous acetic acid solution is 1-2%.

10. The method according to claim 5, characterized in that, In step 2, the concentration of chitosan in the chitosan solution is 0.01–0.02 g / mL.

11. The method according to claim 5, characterized in that, In step 3, the mixing volume ratio of OSA starch aqueous solution and chitosan solution is 0.8 to 1:

1.

12. The method according to claim 5, characterized in that, In step 3, the stirring is carried out at 400-600 r / min for 2-6 hours.

13. The method according to claim 5, characterized in that, In step 4, the mass ratio of OSA starch-chitosan electrostatic complex solution to soybean oil is 0.8–1.2:

1.

14. The method according to claim 5, characterized in that, In step 4, the stirring is carried out at 8000-12000 rpm for 2-5 minutes; the drying temperature is 40-45℃; and the high-speed shearing is carried out at 8000-12000 rpm for 1-5 minutes.

15. The application of the low-oil-loss plastic fat according to any one of claims 1 to 4 in the food industry.

16. A method for preparing bread using the low-oil-loss plastic fat according to any one of claims 1 to 4, comprising the following steps: (1) Weigh out 100-150 parts of high-gluten flour, 50-60 parts of eggs, 2-5 parts of salt, 10-15 parts of sugar, 2-5 parts of yeast and 5-10 parts of oil gel according to the mass fraction; (2) Mix the weighed flour, eggs, salt, sugar and yeast, add 20-50 parts milk and 50-100 parts water, then add oil gel and knead into a smooth dough. (3) Let the kneaded dough rest for 10-15 minutes, then put it into the mold, let it rest for a while longer, and then bake it to get bread.

17. A method for preparing shrimp cake using the low-oil-loss plastic fat according to any one of claims 1 to 4, comprising the following steps: (1) Weigh out 100-150 parts of shrimp paste by weight, then add 5-10 parts of oil gel to the shrimp paste and chop it, then add 1-3 parts of salt and continue chopping, and finally add 1-3 parts of MSG, 5-10 parts of starch and 5-10 parts of chicken white and continue chopping. (2) Place the chopped shrimp paste into a mold and then heat it with steam to make shrimp cake.

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