Dietary fiber system high-oil-loading powdered oil and preparation method thereof

Abstract

The invention discloses dietary fiber system high-oil-loading powdered oil and a preparation method thereof, and belongs to the technical field of food processing. According to the invention, insoluble nanocellulose is used as an emulsion interface stabilizer, water-soluble dietary fiber is used as an emulsion interface enhancer, and the high-oil-loading powdered oil is obtained through spray drying. The method is simple in process and easy to operate, dietary fibers completely replace micromolecular surfactants, grease digestion can be regulated and controlled, important physiological effects are achieved, and the application range of powdered grease is widened.

Description

Technical Field

[0001] The invention belongs to the technical field of food processing, and in particular relates to a dietary fiber high-oil-loaded powdered oil and a preparation method thereof. Background Art

[0002] Powdered fats and oils refer to a large class of solid powdered fat products that can flow freely at room temperature through special processing or dispersion, adsorption and coating of carriers. As a carrier of fat, powdered fats and oils not only provide energy but also improve the taste, plasticity and flavor of food. They are widely used in solid beverages, baking, soups, ice cream and functional food industries, becoming an important raw material for modern food processing and manufacturing and an important carrier for the production of functional foods. The market size of powdered fats and oils will grow to US$6.873 billion in 2023.

[0003] However, small molecule emulsifiers are still needed in the preparation of traditional powdered oils. Due to the limitations of the drying and film-forming ability of small molecule emulsifiers, the requirements of spray drying on the total solids concentration and viscosity of the emulsion, and the easy oxidation of oils, the manufacture of traditional powdered oils requires the addition of a large amount of auxiliary materials, resulting in a generally low oil loading in the product, mostly between 20% and 60%.

[0004] Therefore, the development of healthy high-oil-loaded powdered oils is of great significance to the development of related downstream industries. On the one hand, the large-scale use of small molecule emulsifiers has potential harm to the human body, so the use of small molecule emulsifiers needs to be excluded. However, although some studies have mentioned the omission of small molecule emulsifiers, the obtained powdered oils have a lower oil load. On the other hand, blindly increasing the oil load of powdered oils will also lead to the deterioration of the physical and chemical properties of powdered oils and the deterioration of rehydration properties. At the same time, it is also easy to lead to excessive intake of oils, which in turn leads to a series of health problems. Therefore, the development of a healthy powdered oil needs to pay attention to three aspects: the omission of small molecule emulsifiers, the increase in oil load, and the impact on human health.

[0005] In patent CN116076585A, a low GI powdered oil and its preparation method, although dietary cellulose such as resistant dextrin and inulin is used as the wall material of the low GI powdered oil, small molecule active agents are still used for emulsion stability, and data such as encapsulation rate are not recorded, and the technical effect is vague and unclear.

[0006] In patent CN113647627A, a powdered oil and its preparation method are used. The powdered oil is made of protein or modified starch and small molecule filler as wall materials, and liquid oil, emulsifier and fat-soluble antioxidant as core materials. After being evenly mixed, it is obtained by shearing, homogenizing and spray drying. However, the oil loading of the powdered oil is in the range of 45% to 55%, and a small molecule emulsifier is also used.

[0007] In the preparation method of palm kernel oil powdered fat in patent CN102742674A, although it does not contain small molecule emulsifier and the embedding rate is also very high, the oil loading of the powdered fat is still low (23.8% to 40.5%).

[0008] In patent CN115669938B, a high oil-loaded microcapsule powder with weight loss function and its preparation method and application, the patent uses ultrasound-assisted glycosylation modified protein as the wall material and a mixed oil of olive oil diester oil and sacha inchi oil as the core material to develop a high oil-loaded (70%) oil microcapsule powder. However, the preparation of the wall material is relatively troublesome, requiring ultrasonic pretreatment, followed by pH adjustment for Maillard reaction, long reaction time, and many by-products. Summary of the invention

[0009] Technical issues

[0010] In the preparation of traditional powdered fats, small molecule emulsifiers are required, which have certain impacts on human health. At the same time, some technologies will have the problem of too low oil content after excluding the use of small molecule emulsifiers, and the health of powdered fats is also an issue that needs attention. Therefore, it is necessary to provide a powdered fat that does not use small molecule emulsifiers, has high oil content, is healthy, and has low fat digestion.

[0011] Technical content

[0012] In view of the market demand for high-oil-loaded powdered oils and the pursuit of green, healthy and high-diet products by consumers, the present invention provides a full dietary fiber system high-oil-loaded powdered oil and a preparation method thereof. In the preparation process, the combined use of insoluble dietary fiber and water-soluble dietary fiber completely replaces the use of small molecule emulsifiers. Dietary fiber has the benefits of delaying fat digestion, enhancing satiety, regulating intestinal flora, and preventing cardiovascular and cerebrovascular diseases. It has also been favored by consumers in recent years. If dietary fiber is used to replace small molecule surfactants to prepare high-oil-loaded powdered oils, it is beneficial to improve the flavor and taste of food while reducing the digestion and intake of fats, which has positive significance for improving human sub-health and reducing chronic diseases. At the same time, during the digestion process, dietary fiber will combine with some fatty acids. This combination makes it difficult to be absorbed when fatty acids pass through the digestive tract, thereby reducing the absorption rate of fat.

[0013] The first object of the present invention is to provide a full dietary fiber-based high-oil-loaded powdered fat, which is prepared from the following raw materials, by mass fraction: 1% to 5% nanocellulose, 10% to 35% water-soluble dietary cellulose, 60% to 85% edible oil, and 0.1% to 0.5% cationic stabilizer.

[0014] Furthermore, the nanocellulose has a length of 300 to 1000 nm and a width of 20 to 50 nm.

[0015] Furthermore, the sources of the nanocellulose include purchasing from the market or obtaining through a preparation method.

[0016] Furthermore, the preparation method of the nanocellulose is: taking microcrystalline cellulose and hydrolyzing it with sulfuric acid, collecting the precipitate by centrifugation after the hydrolysis is completed, dispersing the precipitate in water, then dialyzing it, and finally drying the dialysate to obtain the nanocellulose.

[0017] Furthermore, in the method for preparing nanocellulose, the concentration of sulfuric acid is 50-70 wt%.

[0018] Furthermore, in the method for preparing nanocellulose, the solid-liquid ratio of microcrystalline cellulose and sulfuric acid is 1 g:10-20 mL.

[0019] Furthermore, in the method for preparing nanocellulose, the time for sulfuric acid hydrolysis is 30 to 60 minutes.

[0020] Furthermore, in the method for preparing nanocellulose, the dialysis bag used for dialysis has a specification of 8 to 14 kDa.

[0021] Furthermore, the water-soluble dietary fiber is one or more of resistant starch, inulin, β-glucan, pectin, and gum arabic.

[0022] Furthermore, the cationic stabilizer includes one or more of sodium chloride, sodium tripolyphosphate, dipotassium hydrogen phosphate, calcium chloride, calcium silicate, and tricalcium phosphate.

[0023] Furthermore, the edible oils and fats include vegetable oils and animal oils; wherein the vegetable oils include one or more of soybean oil, corn oil, sunflower oil, peanut oil, etc., and the animal oils include one or more of mutton oil, beef tallow, lard, etc.

[0024] The second object of the present invention is to provide a method for preparing a full dietary fiber-based high-oil-loaded powdered fat, wherein the method uses insoluble nanocellulose as an emulsion stabilizer to construct a Pickering emulsion interface layer to stabilize the emulsion, uses water-soluble dietary fiber as an interface modifier to in-situ modify the emulsion interface structure, uses a cationic stabilizer as an interface structure "coagulant" to strengthen the interface structure, and finally prepares the high-oil-loaded powdered fat by spray drying;

[0025] The specific steps of the preparation method are as follows:

[0026] (1) Preparation of emulsion: Nanocellulose is dispersed in water, then poured into the oil phase, emulsified by high-speed shearing, and then subjected to high-pressure homogenization to obtain a primary emulsion;

[0027] (2) Interface modification of the emulsion: adding water-soluble dietary fiber and a cationic stabilizer to the primary emulsion obtained in step (1), stirring evenly, and then high-pressure homogenization to obtain a final emulsion;

[0028] (3) Preparation of powdered oil: The final emulsion obtained in step (2) is spray-dried to obtain a high-oil-loaded powdered oil.

[0029] Furthermore, the preparation method of the nanocellulose in step (1) is as follows: taking microcrystalline cellulose, using 50-70wt% sulfuric acid at a solid-liquid ratio of 1g:10-20mL, hydrolyzing it for 30-60min, collecting the precipitate by centrifugation after the hydrolysis is completed, dispersing the precipitate in water, and then dialyzing it with a 8-14kDa dialysis bag, and finally drying the dialysate to obtain nanocellulose.

[0030] Furthermore, in step (1), the nanocellulose has a length of 300 to 1000 nm and a width of 20 to 50 nm.

[0031] Furthermore, in step (1), the ratio of nanocellulose to water is 0.1-1.5 g:100 mL.

[0032] Furthermore, the oil phase in step (1) includes vegetable oil and animal oil; wherein the vegetable oil includes one or more of soybean oil, corn oil, sunflower oil, peanut oil, etc., and the animal oil includes one or more of mutton oil, beef tallow, lard, etc.

[0033] Furthermore, when the oil phase is animal oil, the animal oil needs to be melted.

[0034] Furthermore, in step (1), the mass ratio of nanocellulose to oil phase is 1-5:60-85.

[0035] Furthermore, the parameters of the high-speed shearing in step (1) are 10000-15000 rpm and 1-5 min.

[0036] Furthermore, the parameters of high pressure homogenization in step (1) are 20 to 40 MPa and 1 to 5 times.

[0037] Furthermore, in step (2), the mass ratio of nanocellulose to water-soluble dietary cellulose is 1-5:10-35.

[0038] Furthermore, in step (2), the mass ratio of nanocellulose to cationic stabilizer is 1-5:0.1-0.5.

[0039] Furthermore, in step (2), the water-soluble dietary fiber is one or more of resistant starch, inulin, β-glucan, pectin, and gum arabic.

[0040] Furthermore, in step (2), the cationic stabilizer includes one or more of sodium chloride, sodium tripolyphosphate, dipotassium hydrogen phosphate, calcium chloride, calcium silicate, and tricalcium phosphate.

[0041] Furthermore, the parameters of the high pressure homogenization in step (2) are 10 to 20 MPa and 1 to 3 times.

[0042] Furthermore, the spray drying conditions in step (3) are: inlet temperature 130-180°C, outlet temperature 60-90°C, and flow rate 0.4-0.8 L / h.

[0043] The third object of the present invention is to provide a complete dietary fiber-based high-oil-loaded powdered fat for use as a food raw material in the food field.

[0044] Furthermore, the application products include solid beverages, hot pot base or ice cream.

[0045] The fourth object of the present invention is to provide a complete dietary fiber-based high-oil-loaded powdered oil for use as a food raw material in the field of preparation of medical and health products.

[0046] Furthermore, the application includes preparing health products for weight loss, as an active substance delivery system, or preparing health products for preventing / alleviating hyperlipidemia.

[0047] Beneficial effects of the present invention:

[0048] 1. The present invention utilizes the interfacial adsorption behavior of insoluble nanocellulose particles to cover nanocellulose at the oil-water interface to prepare a Pickering emulsion system, and then adds soluble dietary fiber to thicken the Pickering emulsion interface layer based on the affinity between cellulose substances. Finally, cationic stability is added to play an electrostatic shielding role, promote the agglomeration of the negatively charged nanocellulose interface layer, and strengthen the interface layer. The process steps are simple, and the insoluble dietary fiber and the soluble dietary fiber are organically combined to achieve the full replacement of small molecule emulsifiers, thereby avoiding the use of small molecule emulsifiers.

[0049] 2. The powdered oil prepared by the present invention has a high oil carrying capacity and strong applicability. It can be used as a food raw material in the food field, and can also be used as a delivery system in the field of medicine and health care products.

[0050] 3. The present invention uses dietary fiber in the preparation of powdered oil, which can combine with fatty acids, making the fatty acids less easily absorbed by the human body, making the powdered oil healthier and meeting the requirements of green, healthy and high-diet products. DETAILED DESCRIPTION

[0051] The preferred embodiments of the present invention are described below. It should be understood that the embodiments are for better explaining the present invention and are not used to limit the present invention.

[0052] Powdered oil measurement indicators:

[0053] Oil loading: Weigh about 1g of powdered oil and add 10mL of 2mol / L HCl solution, stir for 30min to rupture the capsule wall. Then add 40mL of chloroform and 10mL of methanol, and stir again for 30min. Then centrifuge at 10000rpm / min for 10min, collect the organic phase, dry it, and weigh the remaining oil weight. The calculation formula is as follows:

[0054]

[0055] Surface oil content: Add about 1g of powdered oil to 15ml of petroleum ether and stir gently for 1min. Then filter the mixture through a quick filter paper and wash the residue again with 10ml of petroleum ether. After combining the filtrate, place it in an oven at 60°C until the solvent evaporates completely. Then collect the residual oil and weigh it, and calculate the formula:

[0056]

[0057] Embedding rate: The embedding rate of the powder is calculated based on the oil loading and surface oil content of the powder. The calculation formula is as follows:

[0058]

[0059] Reference for in vitro digestion model method: A standardised static in vitro digestion method suitable for food-an international consensus[J].Food Function.2014,5(6),1113-1124.

[0060] The method for determining the release curve of free fatty acids (FFAs) is based on the literature: Modulating in vitro gastrointestinal digestion of nanocellulose-stabilized pickering emulsions by altering cellulose lengths[J]. Food Hydrocolloids. 2021, 118: 106738.

[0061]

[0062] Where V NaOH is the volume of sodium hydroxide solution consumed during the titration, m NaOH is the molar mass of the sodium hydroxide solution, MLipid is the molecular weight of the oil, W Lipid It’s the quality of the oil.

[0063] Unless otherwise specified, the raw materials used in the examples are common commercially available products.

[0064] Example 1

[0065] (1) Preparation of insoluble dietary fiber (nanocellulose): 80 g of microcrystalline cellulose was slowly added with 60% mass concentration of sulfuric acid at a solid-liquid ratio of 1:15 (g / mL) for hydrolysis reaction, and the reaction time was 40 min. After the reaction was completed, the reaction was immediately terminated with 10 times deionized water, and then the supernatant was removed by centrifugation and the precipitate was collected. The precipitate was redispersed in deionized water, dialyzed with an 8-14 kDa dialysis bag to remove excess inorganic salt ions, and then dried to obtain nanocellulose.

[0066] (2) Preparation of emulsion: The nanocellulose in step (1) is used as an emulsion stabilizer to prepare a 0.5% (g / mL) concentration of nanocellulose aqueous phase, 20 g of corn oil is taken as an oil phase, and added to 80 mL of the nanocellulose aqueous phase to obtain a mixed system, and then the mixed system is high-speed sheared at a speed of 10,000 rpm for 2 min to obtain a primary emulsion, and then high-pressure homogenization is performed twice at 30 MPa to obtain a Pickering emulsion.

[0067] (3) Emulsion interface modification: 8.1 g of resistant dextrin was slowly added to the Pickering emulsion and stirred for 10 min. Then a small amount of calcium phosphate (0.05 g) was added and stirred for 10 min. Ultrasonication was performed at 300 W for 5 min, and high-pressure homogenization was performed again at 10 MPa to obtain a mixed emulsion.

[0068] (4) Spray drying: spray drying the mixed emulsion in step (3) to obtain a high oil-loaded powdered oil. The spray drying conditions are: inlet temperature 160° C., outlet temperature 80° C., and flow rate 0.6 L / h.

[0069] Example 2

[0070] (1) Preparation of insoluble dietary fiber (nanocellulose): refer to the steps in Example 1.

[0071] (2) Preparation of emulsion: The nanocellulose in step (1) is used as an emulsion stabilizer to prepare a 0.5% (g / mL) concentration of nanocellulose aqueous phase, 20 g of sheep fat is taken as the oil phase, the sheep fat is preheated to about 60° C., and added to 80 mL of the nanocellulose aqueous phase also preheated to 60° C. to obtain a mixed system, and then the mixed system is high-speed sheared at a speed of 10,000 rpm for 2 min to obtain a primary emulsion, and then high-pressure homogenization is performed twice at 30 MPa to obtain a Pickering emulsion.

[0072] (3) Emulsion interface modification: 8.1 g of resistant dextrin was slowly added to the Pickering emulsion and stirred for 10 min. Then a small amount of calcium phosphate (0.05 g) was added and stirred for 10 min. Ultrasonication was performed at 300 W for 5 min, and high-pressure homogenization was performed again at 10 MPa.

[0073] (4) Spray drying: The emulsion in step (3) is spray dried to obtain a high oil-loaded powdered oil. The spray drying conditions are: inlet temperature 160° C., outlet temperature 80° C., and flow rate 0.6 L / h.

[0074] Example 3

[0075] (1) Preparation of insoluble dietary fiber (nanocellulose): refer to the steps in Example 1.

[0076] (2) Emulsion preparation: The nanocellulose in step (1) is used as an emulsion stabilizer to prepare a 0.5% (g / mL) nanocellulose aqueous phase, 20 g of algae oil is taken as an oil phase and added to 80 mL of the nanocellulose aqueous phase to obtain a mixed system, and then the mixed system is high-speed sheared at a speed of 12000 rpm for 1 min to obtain a primary emulsion, and then high-pressure homogenization is performed twice at 40 MPa to obtain a Pickering emulsion.

[0077] (3) Emulsion interface modification: 8.1 g of resistant dextrin was slowly added to the Pickering emulsion and stirred for 10 min. Then a small amount of calcium phosphate (0.05 g) was added and stirred for 10 min. Ultrasonication was performed at 300 W for 5 min, and high-pressure homogenization was performed again at 10 MPa.

[0078] (4) Spray drying: The emulsion in step (3) is spray dried to obtain a high oil-loaded powdered oil. The spray drying conditions are: inlet temperature 160° C., outlet temperature 80° C., and flow rate 0.6 L / h.

[0079] Example 4

[0080] (1) Preparation of insoluble dietary fiber (nanocellulose): refer to the steps in Example 1.

[0081] (2) Preparation of emulsion: The nanocellulose in step (1) is used as an emulsion stabilizer to prepare a 1% (g / mL) concentration of nanocellulose aqueous phase, 20 g of peanut oil is taken as an oil phase and added to 80 mL of the nanocellulose aqueous phase to obtain a mixed system, and then the mixed system is high-speed sheared at a speed of 12000 rpm for 2 min to obtain a primary emulsion, and then high-pressure homogenization is performed twice at 35 MPa to obtain a Pickering emulsion.

[0082] (3) Emulsion interface modification: 4.1 g of gum arabic was slowly added to the Pickering emulsion and stirred for 10 min. Then a small amount of calcium phosphate (0.08 g) was added and stirred for 10 min. Ultrasonication was performed at 300 W for 5 min, and high pressure homogenization was performed again at 10 MPa.

[0083] (4) Spray drying: The emulsion in step (3) is spray dried to obtain a high oil-loaded powdered oil. The spray drying conditions are: inlet temperature 160° C., outlet temperature 80° C., and flow rate 0.6 L / h.

[0084] Example 5

[0085] (1) Preparation of insoluble dietary fiber (nanocellulose): refer to the steps in Example 1.

[0086] (2) Preparation of emulsion: The nanocellulose in step (1) is used as an emulsion stabilizer to prepare a 1% (g / mL) concentration of nanocellulose aqueous phase, 20 g of peanut oil is taken as an oil phase and added to 80 mL of the nanocellulose aqueous phase to obtain a mixed system, and then the mixed system is high-speed sheared at a speed of 10,000 rpm for 2 min to obtain a primary emulsion, and then high-pressure homogenization is performed twice at 30 MPa to obtain a Pickering emulsion.

[0087] (3) Emulsion interface modification: 1.4 g of resistant dextrin was slowly added to the Pickering emulsion and stirred for 10 min. Then a small amount of calcium phosphate (0.08 g) was added and stirred for 10 min. Ultrasonication was performed at 300 W for 5 min, and high-pressure homogenization was performed again at 10 MPa.

[0088] (4) Spray drying: The emulsion in step (3) is spray dried to obtain a high oil-loaded powdered oil. The spray drying conditions are: inlet temperature 160° C., outlet temperature 80° C., and flow rate 0.6 L / h.

[0089] Example 6

[0090] (1) Preparation of insoluble dietary fiber (nanocellulose): refer to the steps in Example 1.

[0091] (2) Preparation of emulsion: The nanocellulose in step (1) is used as an emulsion stabilizer to prepare a nanocellulose aqueous phase with a concentration of 0.8% (g / mL), 20 g of peanut oil is taken as an oil phase, and added to 80 mL of the nanocellulose aqueous phase to obtain a mixed system, and then the mixed system is high-speed sheared at a speed of 10,000 rpm for 2 min to obtain a primary emulsion, and then high-pressure homogenization is performed twice at 30 MPa to obtain a Pickering emulsion.

[0092] (3) Emulsion interface modification: 7.9 g of inulin was slowly added to the Pickering emulsion and stirred for 10 min. Then a small amount of calcium chloride (0.06 g) was added and stirred for 10 min. Ultrasonication was performed at 300 W for 5 min, and high-pressure homogenization was performed again at 10 MPa.

[0093] (4) Spray drying: The emulsion in step (3) is spray dried to obtain a high oil-loaded powdered oil. The spray drying conditions are: inlet temperature 160° C., outlet temperature 80° C., and flow rate 0.6 L / h.

[0094] Example 7

[0095] (1) Preparation of insoluble dietary fiber (nanocellulose): refer to the steps in Example 1.

[0096] (2) Preparation of emulsion: The nanocellulose in step (1) is used as an emulsion stabilizer to prepare a nanocellulose aqueous phase with a concentration of 0.8% (g / mL), 20 g of peanut oil is taken as an oil phase, and added to 80 mL of the nanocellulose aqueous phase to obtain a mixed system, and then the mixed system is high-speed sheared at a speed of 10,000 rpm for 2 min to obtain a primary emulsion, and then high-pressure homogenization is performed twice at 30 MPa to obtain a Pickering emulsion.

[0097] (3) Emulsion interface modification: 7.9 g of β-glucan was slowly added to the Pickering emulsion and stirred for 10 min. Then a small amount of calcium chloride (0.06 g) was added and stirred for 10 min. Ultrasonication was performed at 300 W for 5 min, and high-pressure homogenization was performed again at 10 MPa.

[0098] (4) Spray drying: The emulsion in step (3) is spray dried to obtain a high oil-loaded powdered oil. The spray drying conditions are: inlet temperature 160° C., outlet temperature 80° C., and flow rate 0.6 L / h.

[0099] Example 8

[0100] (1) Preparation of insoluble dietary fiber (nanocellulose): refer to the steps in Example 1.

[0101] (2) Preparation of emulsion: The nanocellulose in step (1) is used as an emulsion stabilizer to prepare a nanocellulose aqueous phase with a concentration of 0.8% (g / mL), 20 g of peanut oil is taken as an oil phase, and added to 80 mL of the nanocellulose aqueous phase to obtain a mixed system, and then the mixed system is high-speed sheared at a speed of 10,000 rpm for 2 min to obtain a primary emulsion, and then high-pressure homogenization is performed twice at 30 MPa to obtain a Pickering emulsion.

[0102] (3) Emulsion interface modification: 7.9 g of β-glucan was slowly added to the Pickering emulsion and stirred for 10 min. Then a small amount of sodium chloride (0.06 g) was added and stirred for 10 min. Ultrasonication was performed at 300 W for 5 min, and high-pressure homogenization was performed again at 10 MPa.

[0103] (4) Spray drying: The emulsion in step (3) is spray dried to obtain a high oil-loaded powdered oil. The spray drying conditions are: inlet temperature 160° C., outlet temperature 80° C., and flow rate 0.6 L / h.

[0104] Comparative Example 1

[0105] The difference between this comparative example and Example 1 is that a small molecule emulsifier is used instead of nanocellulose as an emulsion interface stabilizer.

[0106] (1) Preparation of emulsion: 20 g corn oil was added to 80 mL of water containing 2 wt % monoglycerol fatty acid ester to obtain a mixed system, and then the mixed system was high-speed sheared at 10,000 rpm for 2 min to obtain a primary emulsion, and then high-pressure homogenization was performed twice at 30 MPa to obtain an emulsion.

[0107] (3) Emulsion interface modification: 8.1 g of resistant dextrin was slowly added to the Pickering emulsion and stirred for 10 min. Then a small amount of calcium phosphate (0.05 g) was added and stirred for 10 min. Ultrasonication was performed at 300 W for 5 min, and high-pressure homogenization was performed again at 10 MPa to obtain a mixed emulsion.

[0108] (4) Spray drying: spray drying the mixed emulsion in step (3) to obtain a high oil-loaded powdered oil. The spray drying conditions are: inlet temperature 160° C., outlet temperature 80° C., and flow rate 0.6 L / h.

[0109] Comparative Example 2

[0110] The difference between this comparative example and Example 1 is that all nanocellulose is used, and no soluble dietary fiber is used.

[0111] (1) Preparation of insoluble dietary fiber (nanocellulose): refer to the steps in Example 1.

[0112] (2) Emulsion preparation: The nanocellulose in step (1) is used as an emulsion stabilizer to prepare a nanocellulose aqueous phase with a concentration of 10.625% (g / mL). 20 g of corn oil is taken as an oil phase and added to 80 mL of the nanocellulose aqueous phase. The mixed system is high-speed sheared at 10,000 rpm for 2 min to obtain a primary emulsion, which is then subjected to two high-pressure homogenizations at 30 MPa to obtain a Pickering emulsion.

[0113] (3) Emulsion interface modification: A small amount of calcium phosphate (0.05 g) was added to the Pickering emulsion in step (2), stirred for 10 min, ultrasonicated at 300 W for 5 min, and homogenized again at 10 MPa.

[0114] (4) Spray drying: The emulsion in step (3) is spray dried to obtain a high oil-loaded powdered oil. The spray drying conditions are: inlet temperature 160° C., outlet temperature 80° C., and flow rate 0.6 L / h.

[0115] Comparative Example 3

[0116] The difference between this comparative example and Example 1 is that no cationic stabilizer is used.

[0117] (1) Preparation of insoluble dietary fiber (nanocellulose): refer to the steps in Example 1.

[0118] (2) Emulsion preparation: The nanocellulose in step (1) is used as an emulsion stabilizer to prepare a 0.5% (g / mL) nanocellulose aqueous phase. 20 g of corn oil is taken as an oil phase and added to 80 mL of the nanocellulose aqueous phase. The mixed system is high-speed sheared at 10,000 rpm for 2 min to obtain a primary emulsion, which is then subjected to two high-pressure homogenizations at 30 MPa to obtain a Pickering emulsion.

[0119] (3) Emulsion interface modification: 8.1 g of resistant dextrin was slowly added into the Pickering emulsion, stirred for 10 min, and then homogenized again under high pressure at 10 MPa.

[0120] (4) Spray drying: The emulsion in step (3) is spray dried to obtain a high oil-loaded powdered oil. The spray drying conditions are: inlet temperature 160° C., outlet temperature 80° C., and flow rate 0.6 L / h.

[0121] Comparative Example 4

[0122] The difference between this comparative example and Example 1 is that an equal amount of maltodextrin is used to replace resistant dextrin in step (3).

[0123] Table 1 Comparison of properties of powdered oils in Examples and Comparative Examples

[0124] Group Soluble dietary fiber Surface oil (%) Encapsulation rate (%) Oil loading (%) <![CDATA[FFA max ]]> Example 1 Resistant dextrin 4.56±0.67 93.82±0.85 73.85±2.11 59％ Example 2 Resistant dextrin 3.07±0.81 95.80±1.25 72.23±1.36 54％ Example 3 Resistant dextrin 4.37±1.17 93.69±2.22 69.24±2.78 60％ Example 4 Gum Arabic 7.54±1.28 90.71±2.46 81.22±3.57 66％ Example 5 Resistant dextrin 10.64±1.83 88.24±2.01 90.51±2.11 68％ Example 6 Inulin 4.11±0.38 94.33±1.24 72.54±1.67 56％ Example 7 β-Glucan 4.84±0.67 93.12±1.59 70.35±0.91 58％ Example 8 β-Glucan 6.24±0.87 90.87±1.34 68.34±1.28 62％ Comparative Example 1 Resistant dextrin \ \ \ Comparative Example 2 \ \ \ \ \ Comparative Example 3 Resistant dextrin 25.33±1.97 58.18±2.11 60.57±3.54 75％ Comparative Example 4 Maltodextrin 7.88±1.21 88.74±1.33 69.96±1.65 80％

[0125] Table 2 Comparison of properties of powdered oils in Examples and Comparative Examples

[0126]

[0127] Comparative Example 1 using a small molecule emulsifier to replace the insoluble dietary fiber (nanocellulose) and Comparative Example 2 not using soluble dietary fiber cannot prepare powdered fats with a high oil loading (70% oil loading).

[0128] The main difference between Examples 1 to 3 is that the internal phase oils are different. The oils used in Examples 1 to 3 are corn oil, sheep oil, and algae oil, respectively. As can be seen from Tables 1 and 2, the change in the oil phase has little effect on the embedding effect of the powdered oil. Since the wall material is dietary fiber, the free fatty acid release rate (FFA) of the emulsion after rehydration is generally low, among which the sheep oil powdered oil in Example 2 has the lowest FFA.

[0129] Embodiments 3 to 5 respectively prepared powdered fats with different oil loadings, and the oil loadings were 69.24%, 81.22%, and 90.51% respectively. As can be seen from Tables 1 and 2, the oil loading affects the properties of powdered fats and rehydrated emulsions. As the oil loading increases, the encapsulation efficiency of the powdered fat decreases. When the oil loading increases to 90%, there are a few aggregated particles in the powdered fat. However, since dietary fiber is used as a wall material, the fat digestibility in the powdered fat increases with the increase of the oil loading, but it is still less than 70%.

[0130] Examples 1, 4, 6, and 7 respectively used different dietary fibers such as resistant dextrin, gum arabic, inulin, and β-glucan. Comparative Example 4 used maltodextrin instead of resistant dextrin. As can be seen from Tables 1 and 2, the fat digestibility of the powdered oil using soluble dietary fiber is significantly lower than that of the maltodextrin (Comparative Example 4) sample, indicating that the dietary fiber combination used in the present invention effectively reduces fat digestion. In addition, resistant dextrin, gum arabic, inulin, and β-glucan have little effect on the properties, digestive behavior, and rehydration of powdered oils.

[0131] The main difference between Examples 7 and 8 is that the cationic stabilizers are different, namely calcium chloride and sodium chloride. As can be seen from Tables 1 and 2, divalent calcium ions have a better embedding effect, and the fat digestibility of the powdered oil after calcium ion treatment is relatively lower.

[0132] The embodiments provided above are not intended to limit the scope of the present invention, and the steps described are not intended to limit the execution order thereof. Those skilled in the art may make obvious improvements to the present invention in combination with existing common knowledge, which also fall within the scope of protection defined by the claims of the present invention.

Claims

1. A complete dietary fiber-based high oil-carrying powdered fat, characterized in that: The powdered fat is prepared from the following raw materials, by mass fraction: 1% to 5% nanocellulose, 10% to 35% water-soluble dietary cellulose, 60% to 85% edible fat, and 0.1% to 0.5% cationic stabilizer; The water-soluble dietary fiber is one or more of resistant starch, inulin, β-glucan, pectin, and gum arabic; The cationic stabilizer includes one or more of sodium chloride, sodium tripolyphosphate, dipotassium hydrogen phosphate, calcium chloride, calcium silicate, and tricalcium phosphate.

2. The full dietary fiber-based high oil-carrying powdered fat according to claim 1, characterized in that: The preparation method of the nanocellulose comprises the following steps: hydrolyzing microcrystalline cellulose with sulfuric acid, collecting precipitates by centrifugation after the hydrolysis is completed, dispersing the precipitates in water, dialyzing the precipitates, and finally drying the dialyzate to obtain the nanocellulose.

3. The full dietary fiber-based high oil-carrying powdered fat according to claim 1, characterized in that: The edible oils and fats include vegetable oils and animal oils; wherein the vegetable oils include one or more of soybean oil, corn oil, sunflower oil, peanut oil, etc., and the animal oils include one or more of mutton oil, beef tallow, lard, etc.

4. A method for preparing the complete dietary fiber-based high oil-carrying powdered fat according to any one of claims 1 to 3, characterized in that: The method steps are as follows: (1) Preparation of emulsion: Nanocellulose is dispersed in water, then poured into the oil phase, emulsified by high-speed shearing, and then subjected to high-pressure homogenization to obtain a primary emulsion; (2) Interface modification of the emulsion: adding water-soluble dietary fiber and a cationic stabilizer to the primary emulsion obtained in step (1), stirring evenly, and then high-pressure homogenization to obtain a final emulsion; (3) Preparation of powdered oil: The final emulsion obtained in step (2) is spray-dried to obtain a high-oil-loaded powdered oil.

5. The preparation method according to claim 4, characterized in that: In step (1), the oil phase includes vegetable oil and animal oil; wherein the vegetable oil includes one or more of soybean oil, corn oil, sunflower oil, peanut oil, etc., and the animal oil includes one or more of mutton oil, beef tallow, lard, etc.; when the oil phase is animal oil, the animal oil needs to be melted.

6. The preparation method according to claim 4, characterized in that: In step (1), the ratio of nanocellulose to water is 0.1-1.5 g:100 mL; the mass ratio of nanocellulose to oil phase is 1-5:60-85.

7. The preparation method according to claim 4, characterized in that: In step (2), the water-soluble dietary fiber is one or more of resistant starch, inulin, β-glucan, pectin, and gum arabic; the cationic stabilizer includes one or more of sodium chloride, sodium tripolyphosphate, dipotassium hydrogen phosphate, calcium chloride, calcium silicate, and tricalcium phosphate.

8. The preparation method according to claim 4, characterized in that: In step (2), the mass ratio of nanocellulose to water-soluble dietary cellulose is 1-5:10-35; the mass ratio of nanocellulose to cationic stabilizer is 1-5:0.1-0.

5.

9. The preparation method according to claim 4, characterized in that: The spray drying conditions in step (3) are: inlet temperature 130-180° C., outlet temperature 60-90° C., and flow rate 0.4-0.8 L / h.

10. Use of the complete dietary fiber-based high-oil-loaded powdered oil according to any one of claims 1 to 3 in the food field or in the preparation of medical and health products.

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