Peanut oil gel and preparation method thereof

Abstract

The invention discloses peanut oil oleogel and a preparation method thereof. The oleogel comprises the following components in percentage by mass: 1-8% of sodium alginate, 12-14% of fish collagen peptide and 78-87% of peanut oil. According to the invention, an oil gel product with high oil content and high stability is prepared by a Pickering emulsion method, and alginate, codfish skin collagen and peanut oil which have more nutritional and health-care values are used as main components, so that the gel product with high oil content (78-87%) and high stability is prepared; the production controllability of oil product solidification and the stability of the oil gel product are improved, and the prepared oil gel has the characteristic of shear thinning and the characteristic of multiple freezing and thawing resistance, so that the processes of pipeline transportation, filling, low-temperature storage and the like in industrial production are convenient to carry out; and a foundation is laid for development and application of high-quality edible oil gel products and oily pharmaceutical preparations.

Description

Technical Field

[0001] The invention relates to the technical field of oleogel preparation, in particular to peanut oil oleogel and a preparation method thereof. Background Art

[0002] In recent years, with the increasing consumption of solid fats and people's awareness of the potential hazards of trans fatty acids and saturated fatty acids, oil gels have received widespread attention. A large number of studies have determined that a variety of oil gel systems have the function of mimicking the physical properties of traditional plastic fats and can be used as a substitute for animal fats in food systems. At the same time, in order to improve the bioavailability of oils, people have begun to focus on choosing healthier oils, such as olive oil and linseed oil. These oils are rich in a variety of unsaturated fatty acids, which can lower blood lipids and prevent cardiovascular and cerebrovascular diseases. Studies have confirmed that the zinc content of peanut oil is many times that of salad oil, corn oil, rapeseed oil, and soybean oil. It also contains anti-aging ingredients, which can delay the aging of brain function. It also has the effects of strengthening the spleen and moistening the lungs, relieving food accumulation, and expelling internal insects.

[0003] Alginate can slow down the absorption of fat, sugar and bile salt, reduce serum cholesterol, triglycerides and blood sugar, and prevent modern diseases such as hypertension and diabetes. Oil gel containing alginate can improve gel stability and controllability, give full play to the nutritional value of peanut oil, and broaden its application path in the food industry.

[0004] Fish collagen comes from aquatic organisms. Compared with terrestrial organisms, it is less polluting and safer. It is currently mainly used in the fields of cosmetics, food and health products. So far, there has been no report of fish viruses being transmitted to humans or animals, so the risk of virus transmission is lower, and it is expected to be used as a new type of collagen in the biomedical field. The relatively high hydrophobicity of fish collagen is conducive to the increase of fat solubility; the antioxidant effect of fish collagen peptides is better than that of pig and bovine collagen peptides. In addition, the structure of fish collagen peptides is similar to that of antihypertensive peptides, and has a more significant antihypertensive effect.

[0005] Studies have shown that oil gel has the potential to completely or partially replace solid fats in food. As a new type of oil gel, it provides certain possibilities for improving the nutritional and physical and chemical conditions of food, and has good application prospects in many fields.

[0006] The existing invention patent [CN105994698B] discloses an edible oil gel using xanthan gum as a gelling agent and soy protein isolate as a Pickering emulsifier, which has a high oil content, but does not disclose whether it has shear thinning properties, which is not conducive to industrial mass production.

[0007] In addition, the existing oil gel preparation technology uses synthetic gelling agents, emulsifiers, and gel strengthening agents, which does not conform to the public's increasingly improved natural and healthy concepts and is not conducive to the promotion and consumption of products. Using natural biopolymers or small molecule gelling agents to construct oil gel systems and load hydrophobic bioactive substances is currently a research hotspot in the food field. Summary of the invention

[0008] The object of the present invention is to provide a high-oil-content, high-stability peanut oil gel and a preparation method thereof. The product can regulate the dynamic viscosity of the gel by the amount of sodium alginate, the shear rate and the temperature. The gel has a shear-thinning property, which is not only convenient for pipeline transportation and filling (such as gel capsules) during industrial production, but also improves the stability of the gel, which is beneficial to the long-term storage of oil-containing foods or medicines.

[0009] To achieve the above object, the present invention provides the following technical solutions:

[0010] A peanut oil gel comprises the following components by mass percentage:

[0011] Sodium alginate: 1-8%

[0012] Fish collagen peptide: 12-14%

[0013] Peanut oil: 78-87%,

[0014] The peanut oil used was commercially available food grade pressed peanut oil.

[0015] The sodium alginate used is food grade seaweed extract with a weight average molecular weight of 32000-400000.

[0016] The fish collagen peptide used is food-grade cod skin collagen peptide with a weight-average molecular weight of 1000-3000 Da.

[0017] Furthermore, a method for preparing peanut oil oleogel includes the preparation of Pickering emulsion and the preparation of oleogel.

[0018] The preparation of the Pickering emulsion includes: (1) preparing a collagen peptide suspension; (2) preparing a sodium alginate solution; (3) preparing a fish collagen peptide-sodium alginate complex; and (4) preparing a Pickering emulsion.

[0019] (1) The preparation steps of collagen peptide suspension are as follows: disperse collagen peptide powder in distilled water in small amounts several times, stir at 600 rpm with a magnetic stirrer at room temperature for 2 hours, place in a 95°C water bath for 30 minutes, and then cool to room temperature.

[0020] (2) The steps of preparing the sodium alginate solution are as follows: dispersing sodium alginate powder in distilled water in small amounts several times, and stirring at 600 rpm and 40° C. until dissolved;

[0021] The concentration of the sodium alginate solution prepared in step (2) is 0.5-4.0 wt%.

[0022] (3) The preparation steps of fish collagen peptide-sodium alginate complex are as follows: the collagen peptide suspension and the sodium alginate solution are mixed and stirred for 5 hours, heated in a water bath at 85°C for 30 minutes, and cooled to room temperature.

[0023] In step (3), the collagen peptide suspension and the sodium alginate solution are mixed in a mass ratio of 1:1.

[0024] (4) Preparation of Pickering emulsion: The fish collagen peptide-sodium alginate complex solution was homogenized at 10,000 rpm for 5 min, peanut oil was added, and the mixture was homogenized at 10,000 rpm for 5 min to obtain the Pickering emulsion.

[0025] The preparation steps of the oil gel are: pre-freezing the prepared emulsion template in a -26°C refrigerator for 24 hours, freeze-drying for 48 hours to obtain an oil gel dry sample, and finally homogenizing the oil gel dry sample at 10,000 rpm for 5 minutes to obtain the oil gel.

[0026] Furthermore, the oil gel of the present invention has the following characteristics, specifically:

[0027] (1) The apparent viscosity of the oil gel decreases with the increase of shear rate, indicating that the oil gel is a non-Newtonian fluid with shear thinning properties.

[0028] (2) The apparent viscosity of the oil gel increases with the increase of the proportion of sodium alginate.

[0029] (3) As the temperature increases, the apparent viscosity of the oil gel decreases.

[0030] (4) Within a certain range, as the concentration of sodium alginate increases, the oil loss rate of the oil gel gradually decreases.

[0031] (5) After three freeze-thaw cycles, the oil gel has good morphological stability, indicating good freeze-thaw resistance.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The invention uses alginate, cod skin collagen and peanut oil which have more nutritional and health value as main components, and not only prepares a gel product with high oil content (78% to 87%) and high stability, but also improves the production controllability of solidification of oil products and the stability of oil gel products, and can also make the prepared oil gel have the characteristics of shear thinning and resistance to multiple freeze-thaw cycles, which is convenient for industrial production of pipeline transportation, filling, low-temperature storage and other processes, and lays a foundation for the development and application of high-quality edible oil gel products and oily pharmaceutical preparations.

[0034] Description of the attached drawings and tables

[0035] Figure 1 Optical microscope magnification of Examples 1-4 (100 times)

[0036] Figure 2 Example 1 Shear thinning line graph (L1 rotor)

[0037] Figure 3 Example 2 Shear thinning line graph (L2 rotor)

[0038] Figure 4 Example 3 Shear thinning line graph (L4 rotor)

[0039] Figure 5 Example 4 Shear thinning line graph (L4 rotor)

[0040] Figure 6 Stability study after freeze-thaw test of Example 1-4 (physical image) DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention and the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] Example 1

[0043] The formula of this embodiment 1 is: the mass ratio of the three ingredients of sodium alginate, fish collagen peptide and peanut oil is 1:13:86.

[0044] Furthermore, the preparation method of the oil gel of the present invention comprises the following specific steps:

[0045] 1. Preparation of Pickering emulsion

[0046] (1) Preparation of sodium alginate solution

[0047] Sodium alginate powder was dispersed in distilled water in small amounts for multiple times, and stirred at 600 rpm and 40° C. until dissolved to obtain a 0.5 wt % sodium alginate aqueous solution.

[0048] (2) Preparation of collagen peptide suspension

[0049] The collagen powder was dispersed in distilled water in small amounts several times, stirred at 600 rpm with a magnetic stirrer for 2 h at room temperature, placed in a 95° C. water bath for 30 min, and then cooled to room temperature to obtain a 6.5 wt% collagen peptide suspension.

[0050] (3) Preparation of fish collagen peptide-sodium alginate complex

[0051] The collagen suspension was mixed with the sodium alginate solution (1:1, g / g) and stirred for 5 h, heated in a water bath at 85°C for 30 min, and cooled to room temperature.

[0052] (4) Preparation of Pickering emulsion

[0053] The fish collagen peptide-sodium alginate complex solution was homogenized at 10000 rpm for 5 min, peanut oil (the weight of which accounted for 86 wt % of the dry weight of the finished oil gel) was added, and the solution was homogenized at 10000 rpm for 5 min to obtain a Pickering emulsion.

[0054] 2. Preparation of oil gel

[0055] The prepared emulsion template was placed in a -26°C refrigerator for pre-freezing for 24 hours, freeze-dried for 48 hours to obtain a dry sample of oil gel, and finally the dry sample of oil gel was homogenized at 10,000 rpm for 5 minutes to obtain oil gel.

[0056] Example 2

[0057] The formula of this embodiment 2 is: the mass ratio of the three ingredients of sodium alginate, fish collagen peptide and peanut oil is 2:12:86.

[0058] Furthermore, the preparation method of the oil gel of the present invention comprises the following specific steps:

[0059] 1. Preparation of Pickering emulsion

[0060] (1) Preparation of sodium alginate solution

[0061] Sodium alginate powder was dispersed in distilled water in small amounts for multiple times, and stirred at 600 rpm and 40° C. until dissolved to obtain a 1 wt % sodium alginate solution.

[0062] (2) Preparation of collagen peptide suspension

[0063] The collagen powder was dispersed in distilled water in small amounts several times, stirred at 600 rpm with a magnetic stirrer for 2 h at room temperature, placed in a 95°C water bath for 30 min, and then cooled to room temperature to obtain a 6 wt% collagen peptide suspension.

[0064] (3) Preparation of fish collagen peptide-sodium alginate complex

[0065] The collagen suspension was mixed with the sodium alginate solution (1:1, g / g) and stirred for 5 h, heated in a water bath at 85°C for 30 min, and cooled to room temperature.

[0066] (4) Preparation of Pickering emulsion

[0067] The fish collagen peptide-sodium alginate complex solution was homogenized at 10000 rpm for 5 min, peanut oil (the weight of which accounted for 86 wt % of the dry weight of the finished oil gel) was added, and the solution was homogenized at 10000 rpm for 5 min to obtain a Pickering emulsion.

[0068] 2. Preparation of oil gel

[0069] The prepared emulsion template was placed in a -26°C refrigerator for pre-freezing for 24 hours, freeze-dried for 48 hours to obtain a dry sample of oil gel, and finally the dry sample of oil gel was homogenized at 10,000 rpm for 5 minutes to obtain oil gel.

[0070] Example 3

[0071] The formula of this embodiment 3 is: the mass ratio of the three ingredients of sodium alginate, fish collagen peptide and peanut oil is 6:13:81.

[0072] Furthermore, the preparation method of the oil gel of the present invention comprises the following specific steps:

[0073] 1. Preparation of Pickering emulsion

[0074] (1) Preparation of sodium alginate solution

[0075] Sodium alginate powder was dispersed in distilled water in small amounts for multiple times, and stirred at 600 rpm and 40° C. until dissolved to obtain a 3 wt % sodium alginate solution.

[0076] (2) Preparation of collagen peptide suspension

[0077] The collagen powder was dispersed in distilled water in small amounts several times, stirred at 600 rpm with a magnetic stirrer for 2 h at room temperature, placed in a 95° C. water bath for 30 min, and then cooled to room temperature to obtain a 13 wt% collagen peptide suspension.

[0078] (3) Preparation of fish collagen peptide-sodium alginate complex

[0079] The collagen suspension was mixed with the sodium alginate solution (1:1, g / g) and stirred for 5 h, heated in a water bath at 85°C for 30 min, and cooled to room temperature.

[0080] (4) Preparation of Pickering emulsion

[0081] The fish collagen peptide-sodium alginate complex solution was homogenized at 10000 rpm for 5 min, peanut oil (the weight of which accounted for 81 wt% of the dry weight of the finished oil gel) was added, and the solution was homogenized at 10000 rpm for 5 min to obtain a Pickering emulsion.

[0082] 2. Preparation of oil gel

[0083] The prepared emulsion template was placed in a -26°C refrigerator for pre-freezing for 24 hours, freeze-dried for 48 hours to obtain a dry sample of oil gel, and finally the dry sample of oil gel was homogenized at 10,000 rpm for 5 minutes to obtain oil gel.

[0084] Example 4

[0085] The formula of this embodiment 4 is: the mass ratio of the three ingredients of sodium alginate, fish collagen peptide and peanut oil is 8:14:78.

[0086] Furthermore, the preparation method of the oil gel of the present invention comprises the following specific steps:

[0087] 1. Preparation of Pickering emulsion

[0088] (1) Preparation of sodium alginate solution

[0089] Sodium alginate powder was dispersed in distilled water in small amounts for multiple times, and stirred at 600 rpm and 40° C. until dissolved to obtain a 4 wt % sodium alginate solution.

[0090] (2) Preparation of collagen peptide suspension

[0091] The collagen powder was dispersed in distilled water in small amounts several times, stirred at 600 rpm with a magnetic stirrer for 2 h at room temperature, placed in a 95°C water bath for 30 min, and then cooled to room temperature to obtain a 7 wt% collagen peptide suspension.

[0092] (3) Preparation of fish collagen peptide-sodium alginate complex

[0093] The collagen suspension was mixed with the sodium alginate solution (1:1, g / g) and stirred for 5 h, heated in a water bath at 85°C for 30 min, and cooled to room temperature.

[0094] (4) Preparation of Pickering emulsion

[0095] The fish collagen peptide-sodium alginate complex solution was homogenized at 10000 rpm for 5 min, peanut oil (the weight of which accounted for 78 wt % of the dry weight of the finished oil gel) was added, and the solution was homogenized at 10000 rpm for 5 min to obtain a Pickering emulsion.

[0096] 2. Preparation of oil gel

[0097] The prepared emulsion template was placed in a -26°C refrigerator for pre-freezing for 24 hours, freeze-dried for 48 hours to obtain a dry sample of oil gel, and finally the dry sample of oil gel was homogenized at 10,000 rpm for 5 minutes to obtain oil gel.

[0098] (I) Observation results and explanation of oil gel optical microscope magnification 100 times

[0099] See also Figure 1 : After each example was placed in a refrigerator at 4°C for 36 hours, there was no obvious stratification phenomenon. When observed under an optical microscope with a magnification of 100 times, the particles of the oil gel had uniform shape and a small average diameter, indicating that the oil gels of Examples 1 to 4 had good stability.

[0100] (II) Test results and explanation of shear thinning properties of oil gel

[0101] Test method: Use a digital viscometer (model DV-1) to measure the viscosity of the oil gel under different temperatures and speeds. Three parallel samples of the same formula are tested and the average viscosity is plotted.

[0102] Results and explanation: See Figure 2 to Figure 5 The apparent viscosity of Examples 1 to 4 shows an overall downward trend with the increase of shear rate, indicating that the oil gel is a non-Newtonian fluid with shear-thinning rheological properties.

[0103] In Examples 1 to 4, the apparent viscosity of the oil gel increases with the increase of the sodium alginate concentration.

[0104] In Examples 1 to 4, as the temperature increases, the apparent viscosity of the oil gel decreases.

[0105] (III) Test results and explanation of oil loss rate of oil gel

[0106] Test method: weigh a 10mL centrifuge tube as M, add 1-2g of oil gel into the centrifuge tube and weigh it as M1; then centrifuge at 4℃ and 2000rpm for 30min, remove the free peanut oil with absorbent cotton and weigh it as M2. The oil loss rate is calculated as follows:

[0107]

[0108] Results and explanations: Referring to Table 1, by comparing the oil loss rates of various examples, it is found that the sodium alginate concentration has a significant effect on the oil loss rate of the oil gel. As the sodium alginate concentration increases, the oil loss rate of the oil gel decreases significantly.

[0109] Table 1 Oil loss rate of oil gel in different embodiments

[0110]

[0111] (Note: Three parallel samples of the same formula were tested and the average value was taken as the final data)

[0112] (IV) Freeze-thaw stability test results and explanation of oil gel

[0113] Test method: The freshly prepared oil gel was subjected to 3 freeze-thaw cycles. In each cycle, the oil gel was stored in a -26℃ refrigerator for 12 hours, and then the sample was taken out and thawed in a 50℃ oven for 1 hour. The freeze-thaw stability of the oil gel was evaluated by inspecting the appearance after freeze-thaw treatment.

[0114] See also Figure 6 (Left: after the first freeze-thaw cycle; middle: after the second freeze-thaw cycle; right: after the third freeze-thaw cycle). After the first freeze-thaw cycle, there was no obvious change in each embodiment; after the third freeze-thaw cycle, no obvious oil layer appeared in the four test tubes of Examples 1 to 4, indicating good freeze-thaw stability.

Claims

1. A peanut oil gel, characterized in that The components include the following by mass percentage: Sodium alginate: 1-8%; Fish collagen peptide: 12-14%; Peanut oil: 78-87%; The sodium alginate used is food-grade seaweed extract with a weight-average molecular weight of 32,000 to 400,000; The fish collagen peptide used is food-grade cod skin collagen peptide with a weight-average molecular weight of 1000-3000 Da.

2. The method for preparing peanut oil oleogel according to claim 1, wherein: Including the preparation of Pickering emulsion and oil gel.

3. The method for preparing peanut oil oleogel according to claim 2, characterized in that: The preparation steps of the Pickering emulsion include: preparation of collagen peptide suspension; preparation of sodium alginate solution; preparation of fish collagen peptide-sodium alginate complex; and preparation of Pickering emulsion.

4. The method for preparing peanut oil oleogel according to claim 3, characterized in that: The preparation steps of the collagen peptide suspension are as follows: disperse the collagen peptide powder in distilled water in small amounts several times, stir at 600 rpm with a magnetic stirrer at room temperature for 2 hours, place in a 95°C water bath for 30 minutes, and then cool to room temperature.

5. The method for preparing peanut oil oleogel according to claim 3, characterized in that: The steps for preparing the sodium alginate solution are as follows: disperse sodium alginate powder in distilled water in small amounts for multiple times, and stir at 600 rpm and 40° C. until dissolved.

6. The method for preparing peanut oil oleogel according to claim 5, characterized in that: The concentration of the sodium alginate solution is 0.5-4.0 wt %.

7. The method for preparing peanut oil oleogel according to claim 3, characterized in that: The preparation steps of the fish collagen peptide-sodium alginate complex are as follows: the collagen peptide suspension and the sodium alginate solution are mixed and stirred for 5 hours, heated in an 85° C. water bath for 30 minutes, and cooled to room temperature.

8. The method for preparing peanut oil oleogel according to claim 7, characterized in that: The collagen peptide suspension and the sodium alginate solution are mixed in a mass ratio of 1:

1.

9. The method for preparing peanut oil oleogel according to claim 3, characterized in that: The preparation steps of Pickering emulsion are as follows: homogenize the fish collagen peptide-sodium alginate complex solution at 10000 rpm for 5 minutes, add peanut oil, and homogenize at 10000 rpm for 5 minutes to obtain Pickering emulsion.

10. The method for preparing peanut oil oleogel according to claim 2, characterized in that: The preparation steps of the oil gel are: pre-freezing the prepared emulsion template in a -26°C refrigerator for 24 hours, freeze-drying for 48 hours to obtain an oil gel dry sample, and finally homogenizing the oil gel dry sample at 10,000 rpm for 5 minutes to obtain the oil gel.

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