A nutrient delivery system and preparation method thereof

Abstract

The present invention discloses a nutrient delivery system and a preparation method thereof, and belongs to the field of food technology. The nutrient delivery system comprises a protein composition of different molecular weights, nutrients and oil; wherein the protein composition of different molecular weights has a content of 5-10 wt%, an oil content of 1-5 wt%, a nutrient content of 0.001-0.2 wt%, and the rest is water. The present invention can regulate the structure of mixed micelles after emulsion digestion by compounding proteins of different molecular weights, thereby effectively improving the digestion and absorption utilization rate (bioavailability) of nutrients.

Description

Technical Field

[0001] The invention relates to a nutrient delivery system, in particular to a nutrient delivery system for improving the digestion, absorption and utilization rate of functional nutrients and a preparation method thereof, belonging to the technical field of food. Background Art

[0002] In the field of special diets, liquid formula nutrition products and other food fields, products usually include protein, fat, carbohydrates, various nutrients and minerals, in order to provide consumers with balanced and comprehensive nutrition. However, a common problem at present is the low digestion and absorption rate of nutrients, especially fat-soluble nutrients (such as curcumin, vitamin D, lutein, vitamin A, vitamin E, vitamin K, etc.) and minerals (calcium, magnesium, iron, zinc, etc.). A clinical trial report showed that after taking 8g of curcumin orally every day, the steady-state mass concentration in plasma that can be achieved by the third day is only 22-41 ng / mL (Dhillon, Navneet, et al. "Phase II trial of curcumin in patients with advanced pancreatic cancer." Clinical cancer research 14.14 (2008): 4491-4499.).

[0003] After being ingested by the human body, dietary or loaded nutrients enter the gastrointestinal digestive system through the mouth. After undergoing complex physiological conditions, the dietary or nutrient carriers are digested and hydrolyzed, and the nutrients are released and absorbed, entering the human body to exert their effects and improve physical health. Bioavailability refers to the degree to which nutrients are absorbed and utilized in organisms, and is a core indicator for measuring their nutritional value. In research in this field, in vitro digestion models evaluate the bioavailability of target nutrients by simulating conditions in the stomach and small intestine, and are a common and efficient technical means to study nutrient bioavailability.

[0004] Improving the solubility of nutrients can improve the digestion, absorption and utilization of nutrients to a certain extent. For example, patent WO2016007515A1 discloses a nutrient delivery system that combines plant (pea protein, rice protein) and animal protein (casein), and optimizes the ratio between proteins and between proteins and minerals by utilizing the different binding abilities of different proteins with minerals such as calcium, zinc and iron, thereby improving the solubility of minerals and thus increasing the absorption rate of minerals.

[0005] In order to further improve the digestion and absorption utilization rate of nutrients, the art also improves it by designing nutrient delivery systems. At present, the technical means of nutrient delivery systems mainly include: emulsion delivery system, microcapsule embedding delivery system, liposome delivery system, etc. Among them, the application of microcapsule embedding delivery system and liposome delivery system in food is concentrated in the preparation of functional small ingredients. These technologies cannot be directly applied in the commercial production of liquid formula nutrients.

[0006] At present, how to improve the digestion, absorption and utilization rate of nutrients in liquid formulas is an urgent problem to be solved in this field. Summary of the invention

[0007] In order to overcome the shortcomings of low nutrient digestion and absorption utilization rate in the prior art, the present invention proposes a new nutrient delivery system, that is, preparing an emulsion by compounding protein raw materials of different molecular weights (such as concentrated milk protein + collagen peptide) to load nutrients. The structure of the mixed micelles (PPCC: Poly-Peptide Chamber Constructor) after emulsion digestion is regulated by using protein raw materials of different molecular weights, thereby achieving the purpose of improving the digestion and absorption utilization rate of nutrients.

[0008] In order to achieve the above-mentioned purpose, the first aspect of the present invention provides a nutrient delivery system: comprising a protein composition with different molecular weights, nutrients and oil; wherein the protein composition with different molecular weights has a content of 5-10 wt%, the oil content is 1-5 wt%, the nutrient content is 0.001-0.2 wt%, and the rest is water.

[0009] Preferably, the protein composition of different molecular weights refers to a composition of small molecular proteins and large molecular proteins, including collagen peptides (CPT) and concentrated milk protein (MPC).

[0010] Preferably, in the nutrient delivery system, the mass ratio of CPT to MPC is (0.11~3):1.

[0011] Preferably, the nutrients are functional nutrients or minerals.

[0012] Preferably, the functional nutrient is a fat-soluble nutrient selected from one or more of curcumin, β-carotene, etc.

[0013] Preferably, the mineral is one or more of calcium, magnesium, iron, zinc, selenium, etc.; the mineral can be an endogenous mineral, such as derived from concentrated milk protein, or additionally added.

[0014] Preferably, the oil is one or more of coconut oil, soybean oil, peanut oil, high oleic sunflower oil, anhydrous butter, etc., to provide the oil phase.

[0015] The second aspect of the present invention provides a method for preparing the above-mentioned nutrient delivery system:

[0016] The preparation method comprises the following steps:

[0017] (1) weighing a protein composition of different molecular weights according to a certain proportion, adding the mixture to water, and stirring until the mixture is evenly dispersed to obtain an aqueous phase;

[0018] (2) mixing the nutrients with the oil and stirring until they are completely dissolved to obtain an oil phase;

[0019] (3) mixing the two phases and shearing them using a high-speed shearing machine to obtain a crude emulsion;

[0020] (4) homogenizing the prepared crude emulsion to obtain a stable and uniform protein emulsion, i.e., the nutrient delivery system.

[0021] Preferably, the shearing speed of the high-speed shearing machine is 11000-15000 rpm, and the shearing time is 2-10 min.

[0022] Preferably, the total homogenization pressure is 150-300 bar.

[0023] The present invention has the following beneficial effects:

[0024] The nutrient delivery system provided by the present invention can be applied to liquid formula nutritional products. By compounding protein raw materials with different molecular weights (such as compounding MPC and CPT), the structure of mixed micelles after emulsion digestion can be regulated, and the digestion, absorption and utilization rate (bioavailability) of the loaded nutrients can be effectively improved. The bioavailability of curcumin can be increased to 93.5% at most, an increase of 1.35 times, the bioavailability of β-carotene can be increased to 93.9% at most, an increase of 1.46 times, and the bioavailability of calcium can be increased to 40.6%, an increase of 1.5 times.

[0025] The addition of peptides to the emulsion will not affect its encapsulation rate of nutrients, and the encapsulation rate is as high as over 95%. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is the encapsulation efficiency of curcumin;

[0027] Figure 2 The bioavailability of curcumin;

[0028] Figure 3 for the bioavailability of calcium;

[0029] Figure 4 The microstructure of the small intestinal fluid after emulsion digestion of different nutrient delivery systems of the present invention. DETAILED DESCRIPTION

[0030] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0031] Table 1 Raw material ratios and experimental results of Examples 1-9

[0032]

[0033]

[0034] Note: The nutrients in Examples 7-9 are derived from concentrated milk protein, which is endogenous calcium and has no encapsulation rate.

[0035] Examples 1-6

[0036] (1) According to the ratio shown in Table 1, weigh CPT and MPC, add them into water, and stir until they are evenly dispersed to obtain an aqueous phase;

[0037] (2) Mixing nutrients and oil, stirring until completely dissolved to obtain an oil phase;

[0038] (3) Mixing the water phase and the oil phase, shearing them using a shearing machine (shearing speed 11000 rpm, time 10 min) to obtain a crude emulsion;

[0039] (4) The prepared crude emulsion is homogenized (the total homogenization pressure is 150 bar) to obtain a protein emulsion, which is the nutrient delivery system provided by the present invention.

[0040] Embodiment 7-9

[0041] (1) According to the ratio shown in Table 1, weigh MPC and CPT, add them into water, and stir until they are evenly dispersed to obtain an aqueous phase;

[0042] (3) Mixing the water phase and the oil phase, shearing them using a shearing machine (shearing speed 15000 rpm, time 2 min) to obtain a crude emulsion;

[0043] (4) The prepared crude emulsion is homogenized (the total homogenization pressure is 300 bar) to obtain a protein emulsion, which is the nutrient delivery system provided by the present invention.

[0044] Comparative Examples 1-7

[0045] (1) Weigh the raw materials and proportions shown in Table 2, and stir the raw materials until they are evenly dispersed to obtain an aqueous phase;

[0046] (2) Mixing nutrients and oil, stirring until completely dissolved to obtain an oil phase;

[0047] (3) Mixing the water phase and the oil phase, shearing them using a shearing machine (shearing speed 15000 rpm, time 2 min) to obtain a crude emulsion;

[0048] (4) The prepared crude emulsion is homogenized (the total homogenization pressure is 300 bar) to obtain a protein emulsion.

[0049] Table 2 Raw material ratios and experimental results of comparative examples 1-7

[0050]

[0051]

[0052] Effect example

[0053] The comparative samples that failed to form stable emulsions were not further tested for nutrient bioavailability.

[0054] 1. In vitro simulated digestion

[0055] Oral cavity: Take 5 mL of the emulsion sample in each embodiment and comparative examples 1, 4, and 7 and mix with 4 mL of simulated saliva, add 25 µl of 0.3 M CaCl2 and then add mucin to make the concentration in the mixture reach 0.0015 g / mL, stir at 37°C for 2 min at a stirring speed of 100 r / min (the whole process is carried out under this condition);

[0056] Stomach: Take 8 mL of simulated gastric digestive fluid and mix it with oral digestive fluid, add 5 µl of 0.3 M CaCl2, adjust the pH to 3.0, and then add pepsin to make its enzyme activity in the mixture reach 2000 U / mL, and continue the reaction for 1 h;

[0057] Small intestine: Add 8 mL of simulated small intestine digestion solution, 40 µL of 0.3 MCaCl2 and 3 mL of bile salt extract (200 mg / mL) solution to the above sample digested with simulated gastric juice, adjust the pH to 7.0 with 3 M NaOH, then add the freshly prepared lipase suspension and continue the reaction for 2 h.

[0058] 2. Determination of functional nutrients content

[0059] After digestion, the small intestinal digestive fluid was immediately centrifuged at 4°C (12000r / min, 30min). The clear and transparent liquid in the middle layer was the "micelle" layer. The micelle layer was carefully removed with a needle syringe.

[0060] Take 2 mL of sample and add 8 mL of anhydrous ethanol, vortex to mix, and then centrifuge (12000 r / min, 15 min, 25°C) to collect the supernatant. Use a UV spectrophotometer to measure the absorbance of the supernatant at the maximum absorption wavelength of the nutrient component, and then convert it to the concentration of the nutrient component based on the standard curve. According to the calculation results, the encapsulation rate can be expressed as:

[0061]

[0062] Wherein, C1 is the concentration of the nutrient in the emulsion (mg / mL); C0 is the concentration of the nutrient added when preparing the emulsion, which is the theoretical content (mg / mL).

[0063] According to the calculation results, the bioavailability can be expressed as:

[0064]

[0065] In the formula, C digesta is the concentration of nutrients in the small intestinal digestive juice (mg / mL), C micelle is the concentration of the nutrient in the micelle (mg / mL).

[0066] 3. Observation of the microstructure of small intestinal fluid after digestion

[0067] Take the digestive fluid after small intestine digestion, centrifuge and take the supernatant micelle phase, filter it with a 0.45μm filter, and stain it with Nile red (excitation wavelength = 488 nm). Take 10 μL of the sample and place it on a slide, cover it with a coverslip and observe it under a 100× or 20× objective lens using a laser confocal microscope (CLSM).

[0068] The calculation results are shown in Table 1. Figure 1-3 The microstructure of the intestinal fluid after emulsion digestion was observed using confocal laser scanning microscopy (CLSM). Figure 4 As shown. Adding peptides to the emulsion system is conducive to the formation of PPCC in the mixed micelles of small intestinal fluid ( Figure 4 As shown in the yellow circle), this is because after the emulsion passes through the physiological barrier of the gastrointestinal tract, the emulsion carrier will be hydrolyzed in the small intestine, and the digestion products will form mixed micelles with active substances such as bile salts and phospholipids in the small intestine. The mixed micelles will re-dissolve and load fat-soluble nutrients, and then be adsorbed to the small intestinal mucosa and absorbed into the human body through transport. The evolution of the mixed micelle structure during digestion will affect the efficiency of nutrient absorption. Therefore, the nutrient delivery system in the present invention improves the bioavailability of nutrients through the PPCC structure formed during the digestion process. Compared with the comparative example, it can be seen that the nutrient delivery system provided by the present invention can regulate the structure of the mixed micelles after emulsion digestion through the compounding of MPC and CPT, thereby improving the bioavailability of nutrients, and has a synergistic effect.

[0069] from Figure 1 It can be seen that the bioavailability of curcumin in the control group (5wt% MPC) is 69.1%. The addition of collagen peptides to the emulsion system can improve the bioavailability of curcumin. The ratio of collagen peptides to MPC increased from 0.11:1 to 3:1, which can significantly improve the bioavailability of curcumin, up to 1.35 times, to 93.5%.

[0070] β-carotene, the bioavailability of β-carotene in the control group (5% MPC) is 64.5%. Adding collagen peptides to the emulsion system can increase the bioavailability of β-carotene by up to 1.46 times, increasing the bioavailability of β-carotene to 93.9%. Since β-carotene is a nutritional enhancer of vitamin A, improving the bioavailability of β-carotene can improve the bioavailability of fat-soluble nutrients.

[0071] from Figure 2 It can be seen that the bioavailability of calcium in the control group (5% MPC) is 27.0%. Adding collagen peptides to the emulsion system can improve the bioavailability of calcium. The ratio of collagen peptides to MPC increased from 0.11:1 to 1:1, which can significantly improve the bioavailability of calcium, up to 1.5 times.

[0072] It should be noted that when 5% collagen peptide was used alone for the bioavailability experiment of nutrients, no stable emulsion could be formed.

Claims

1. A nutrient delivery system, characterized in that: An emulsion is prepared by compounding protein raw materials with different molecular weights, including protein compositions with different molecular weights, nutrients and oil; wherein the protein compositions with different molecular weights have a content of 5-10 wt%, an oil content of 1-5 wt%, a nutrient content of 0.001-0.2 wt%, and the rest is water; the protein compositions with different molecular weights include collagen peptides and concentrated milk protein, and the mass ratio of the collagen peptides to the concentrated milk protein is (0.11-3):1; the nutrients are functional nutrients or minerals, and the functional nutrients are fat-soluble nutrients.

2. The nutrient delivery system according to claim 1, characterized in that The oil is at least one of coconut oil, high oleic sunflower oil, peanut oil, soybean oil and anhydrous butter.

3. The nutrient delivery system according to claim 1, characterized in that The fat-soluble nutrient is at least one of curcumin and beta-carotene.

4. The nutrient delivery system according to claim 1, characterized in that The minerals are one or more of calcium, magnesium, iron, zinc and selenium.

5. The method for preparing the nutrient delivery system according to any one of claims 1 to 4, characterized in that: The preparation method comprises the following steps: (1) Weighing a protein composition of different molecular weights in proportion and adding it to water, stirring until uniformly dispersed, to obtain an aqueous phase; (2) Mixing nutrients and oil, stirring until completely dissolved to obtain an oil phase; (3) mixing the two phases and shearing them using a high-speed shearing machine to obtain a crude emulsion; (4) homogenizing the prepared crude emulsion to obtain a stable and uniform protein emulsion, i.e., the nutrient delivery system.

6. The preparation method according to claim 5, characterized in that: The shearing speed of the high-speed shearing machine is 11000-15000 rpm, and the shearing time is 2-10 min; the total homogenization pressure is 150-300 bar.

Images