Preparation Process of High-Temperature Resistant Core-Injected Gel Product Containing Spirulina Total Carotenoids

Abstract

The invention discloses a preparation process of a high-temperature-resistant core-injected gel product containing spirulina total carotenoids. By encapsulating total carotenoids with liposomes, the invention solves the problems of poor water solubility and heat sensitivity of total carotenoids. Furthermore, with lecithin molecules as a medium, total carotenoid molecules can be connected to sodium alginate molecules. By controlling process conditions, a high water content and a bursting effect are achieved, which are applied to the production of core-injected gel gummies. The gummies and other products prepared by the invention not only contain the nutritional value of total carotenoids and improve the utilization rate of total carotenoids in human digestion and absorption, but also can withstand high temperatures without melting, filling the gap of spirulina total carotenoids in the field of leisure foods.

Description

Technical Field

[0001] The present invention relates to a preparation process of a high-temperature resistant core-injected gel product containing spirulina total carotenoids, belonging to the technical field of food processing. Background Art

[0002] As a representative of new health foods, spirulina has a much higher carotenoid content than carrots, and this rich and high-quality carotenoid in spirulina cannot be ignored. Almost all of the carotenoids in spirulina are β-carotene and its derivatives, with a relatively low lutein content, while in other green algae, the lutein content accounts for more than half. Therefore, spirulina carotenoids have better health care effects than other green algae. β-Carotene, as a precursor of vitamin A, has good health care functions, but due to its special liposolubility and sensitivity to heat, its application in the field of snack foods is extremely rare. Therefore, solving the problems of liposolubility and thermosensitivity of carotenoids is the key technical means for their application in snack foods.

[0003] In terms of the foodization of spirulina, in Patent CN 201611000373.4, a functional food with the effects of protecting eyesight, relieving eye fatigue and preventing light damage was prepared by using a small amount of spirulina carotenoid extract β-carotene and other components. In Patents CN202010601975.5, CN201110060435.1, CN201410200778.7, CN201410403379, and CN931149509, the whole spirulina thallus was used as an ingredient for food production through various processing techniques.

[0004] In terms of liposome hydrogel embedding, in Patents CN202210617994.6, CN202210592707.0, CN202210015233.3, CN201910660259.1, CN201710325262.9, and CN201810841562.7, liposome hydrogels were used to embed a certain water-soluble drug and applied in the biomedical field.

[0005] In the preparation of gel confectionery products, Patent CN202210786118 discloses a preparation process of kiwifruit polysaccharide extraction gel gummies, which uses a gelling agent for gelation and extracts, retains and applies the water-soluble nutrients in kiwifruit peels. Patent CN202210336178.8 discloses a jelly product composed of a composite colloid solution, an internal soluble food raw material, and a gel food protection solution. The finished product can withstand a temperature of 80 - 95°C without melting, and the taste can maintain stable elasticity and toughness. In Patent CN202210476018.3 and Patent CN202210794358, gelling agents such as carrageenan, gelatin, agar, and gellan gum are used, and the method of pouring with edible colloids is used to produce gel gummies with a lower moisture content. In Patent CN202110672648.3, glutinous rice flour and sodium carboxymethylcellulose are used to replace most of the colloid components such as carrageenan and gelatin to prepare gel gummies, and the temperature that the product can withstand is 65°C.

[0006] It is not difficult to see that in the above patents, the foodization of spirulina is almost limited to directly processing the whole algal body, lacking the application of total carotenoids in spirulina. The application of the liposome hydrogel embedding model only stays in the biomedical field, without being applied to the food processing field, nor to the embedding of fat-soluble nutrients. Summary of the Invention

[0007] In view of the above problems, the present invention provides a preparation process of a high-temperature resistant core-injected gel product containing total carotenoids in spirulina. This process solves the difficulties in the application of thermosensitive and fat-soluble nutrients in gel-based snack foods. By encapsulating total carotenoids with liposomes, the problems of poor water solubility and heat sensitivity are solved. Furthermore, with lecithin molecules as the medium, total carotenoid molecules can be connected with sodium alginate molecules, and by controlling the process conditions, it can achieve a high water content and a bursting effect, and is applied to the production of core-injected gel gummies. The gummies and other products prepared by the present invention not only contain the nutritional value of total carotenoids and improve the utilization rate of total carotenoids in human digestion and absorption, but also can not melt at high temperatures, filling the gap of total carotenoids in spirulina in the field of snack foods.

[0008] The technical solution of the present invention is: A preparation process of a high-temperature resistant core-injected gel product containing total carotenoids in spirulina, characterized in that,

[0009] (1) Extraction of total carotenoids in spirulina

[0010] Add spirulina powder to methanol for cell wall breaking, and then carry out total carotenoid extraction through saponification, extraction, and rotary evaporation;

[0011] (2) Liposome encapsulation of total carotenoids

[0012] Dissolve the extracted total carotenoids together with egg yolk lecithin and cholesterol in ethanol, and perform ultrasonic treatment to completely dissolve them; then slowly inject into water, and heat and stir in a water bath until the ethanol in the solution completely volatilizes to obtain a total carotenoid liposome suspension;

[0013] (3) Preparation of Spirulina total carotenoid liposome hydrogel products

[0014] Based on the cross-linking effect of sodium alginate and calcium ions, obtain a high-temperature resistant gel product capable of carrying total carotenoid liposomes, specifically as follows:

[0015] Preparation of core-injected gel gummies: Prepare the fruit juice, add sodium alginate for gelatinization, and after gelatinization, add the obtained sodium alginate fruit juice solution to the total carotenoid liposome suspension, stir until the sodium alginate is completely dissolved, and then let it stand until the bubbles completely disappear; then drop the above solution into an aqueous solution containing calcium ions at a constant speed for cross-linking for 4 - 6 min to achieve the best cross-linking degree, and wash with pure water to obtain core-injected gel gummies;

[0016] Preparation of core-injected gel jelly: Prepare the fruit juice, add sodium alginate for gelatinization, mix it with the total carotenoid liposome suspension after gelatinization and ensure that the sodium alginate is completely dissolved, and then let it stand to completely eliminate the bubbles; slowly and evenly add a calcium ion solution to the above solution, and let it stand for cross-linking for 30 - 40 min to achieve the best cross-linking degree to obtain core-injected gel jelly;

[0017] Preparation of facial mask: Add sodium alginate to the total carotenoid liposome suspension preheated to 70 - 90 °C, stir until the sodium alginate is completely dissolved; then add glycerol and propylene glycol, homogenize and emulsify, cool down, adjust the pH to 6.5 - 7.0, and then filter and let it stand to obtain the primary product facial mask essence; soak the facial mask paper and it can be used.

[0018] Furthermore, in the step (1),

[0019] The cell wall breaking is: Add Spirulina powder to methanol, and place it in a magnetic stirrer for cell wall breaking;

[0020] The saponification is: Centrifuge the suspension after cell wall breaking, filter the supernatant, add potassium hydroxide and place it on a magnetic stirrer for saponification; centrifuge the saponified solution, and filter the obtained supernatant;

[0021] The extraction is: Extract the saponified solution with petroleum ether, and wash the upper layer of the extraction solution with ultrapure water until no green color is washed out.

[0022] Furthermore, in the above step (2), for total carotenoids, egg yolk lecithin, and cholesterol, the mass ratio of the three is 1:15 - 20:3 - 5.

[0023] Furthermore, in the above step (3),

[0024] During the preparation of the core-injected gel gummy, based on the mass of the fruit juice, the addition amount of the all-carotenoid liposome suspension (the all-carotenoid content is 0.01 - 0.05 mg / mL, the same below) is 15% - 25% (the best is 20%), and the dosage of sodium alginate is 1.8% - 2.2%; the solution containing calcium ions is calcium lactate, and the concentration is 3% - 5%;

[0025] During the preparation of the core-injected gel jelly, based on the mass of the fruit juice, the addition amount of the all-carotenoid liposome suspension is 15% - 25% (the best is 20%), and the dosage of sodium alginate is 1.2% - 1.8%; the solution containing calcium ions is calcium lactate, and the concentration is 1.8% - 2.2%;

[0026] For the preparation of the facial mask, the addition amount of sodium alginate is 0.8% - 1.0% of the all-carotenoid liposome suspension.

[0027] The existing disadvantages in the food application of spirulina are as follows:

[0028] (1) The existing technology has not maximized the nutritional value of the specific nutrients in spirulina compared with the present technology. The main reason is that most of the existing technologies add the whole spirulina to food. However, spirulina has a relatively hard cell wall, and the internal nutrients are difficult to be dissolved out. Moreover, the fat-soluble nutrients are difficult to be digested and absorbed in the aqueous phase system of human gastrointestinal fluids.

[0029] (2) The existing technology lacks the food application of all-carotenoids in spirulina. There is no food application of all-carotenoids in spirulina in the existing technology. Even for the application of the β-carotene extracted from spirulina all-carotenoids, it is modified to be water-soluble before application (Patent CN20161100037).

[0030] (3) The existing gel gummies are basically prepared by the method of pouring edible colloids such as gelatin, pectin, and gellan gum. They are easy to melt at high temperatures and have poor water retention. There is a technology for withstanding high temperatures of 60 - 90°C in the preparation of jelly, but there is no possibility of adding fat-soluble nutrients to the product.

[0031] Compared with the existing technology, the present invention uses high-purity all-carotenoids extracted from spirulina as raw materials to prepare leisure foods, realizing the food application of spirulina all-carotenoids while preparing and applying a high-temperature-resistant gel model for fat-soluble nutrients.

[0032] At present, lipid-soluble nutrient gels generally use gelling agents to cool and gel. The present invention has studied a high-temperature resistant gel that can carry lipid-soluble nutrients based on the cross-linking effect of sodium alginate and calcium ions. At the same time, the lecithin head selected in this study can polymerize well with sodium alginate, and the tail can form a stable bond with all-carotenoids. It connects the entire system like a hub, enabling all-carotenoids to be applied in sodium alginate gel products.

[0033] In summary, the present invention solves the difficulties in the application of thermosensitive and lipid-soluble nutrients in gel-based snack foods. By encapsulating all-carotenoids with liposomes, the problems of poor water solubility and heat sensitivity are solved. Furthermore, with lecithin molecules as the medium, all-carotenoid molecules can be connected to sodium alginate molecules. The product not only contains the nutritional value of all-carotenoids, improves the utilization rate of all-carotenoids in human digestion and absorption, but also does not melt at high temperatures. The present invention can also be applied to the preparation of high-temperature resistant gel products for other lipid-soluble nutrients. In addition, there are currently no snack foods prepared from Spirulina all-carotenoids, and the present invention fills the gap in the field of snack foods for Spirulina all-carotenoids. Description of the Drawings

[0034] Figure 1 Is the ultraviolet absorption spectrum of free all-carotenoids and Car-Lip;

[0035] Figure 2 Are the transmission electron micrographs of blank liposomes (a, b) and Car-Lip (c, d) at 100 nm and 600 nm;

[0036] Figure 3 Are the ABTS radical (A) and DPPH radical (B) scavenging rates of free all-carotenoids and Car-Lip;

[0037] Figure 4 The change rate of TBARS in the oxidation systems of blank liposomes (A) and Car-Lip (B);

[0038] Figure 5 Are the bioavailability of all-carotenoids of free all-carotenoids and Car-Lip during in vitro digestion simulation;

[0039] Figure 6 Are the scanning electron micrographs of B-hy (A), Lip-hy (B) and Car-Lip-hy (C);

[0040] Figure 7 Are the XRD patterns of B-hy, Lip-hy and Car-Lip-hy;

[0041] Figure 8XPS spectra of B-hy, Lip-hy and Car-Lip-hy;

[0042] Figure 9 Car-Lip high temperature stability diagram;

[0043] Figure 10 Comparison of anti-deformation rates between core-injected gummies and commercially available gummies;

[0044] Figure 11 Pictures of the high temperature resistant core-injected gel gummy product containing spirulina total carotenoids. The left picture is the actual prepared product, and the right picture shows the bursting characteristics of the product. Detailed implementation manners

[0045] The present invention will be described below in conjunction with embodiments and drawings.

[0046] Example 1:

[0047] The preparation process of the high temperature resistant core-injected gel gummy containing spirulina total carotenoids of the present invention specifically includes the following steps:

[0048] 1. First, extract spirulina total carotenoids by breaking the cell wall of spirulina powder, saponifying, extracting, rotary evaporation, and re-dissolving to extract total carotenoids.

[0049] (1) Cell wall breaking: Using methanol as the extraction solvent, mix spirulina powder (30 g) and methanol (600 g) at a weight ratio of 1:20, place it in a magnetic stirrer, and stir at a rotation speed of 1000 rpm for 100 - 120 min for cell wall breaking;

[0050] (2) Saponification: Centrifuge the cell wall broken suspension at 4°C and 6000 r for 10 min; After filtering the supernatant after centrifugation, add potassium hydroxide according to a dosage of 0.3 mol / L and saponify on a magnetic stirrer for 120 min; After saponification, centrifuge the solution at 4°C and 7000 r for 10 min, and then filter the obtained supernatant;

[0051] (3) Extraction: Extract the saponified solution in petroleum ether at a ratio of 2:3 (v / v), and wash the upper layer of the extract with ultrapure water more than 5 times until no green color is washed out;

[0052] (4) Rotary evaporation and re-dissolving: Transfer the extract to a distillation flask, rotate and evaporate at 35°C until the liquid in the flask completely evaporates, and then continue rotary evaporation for 30 min (total carotenoid powder can be directly obtained by drying), immediately re-dissolve with 20 ml of ethanol, and filter through a 0.45 μm filter membrane. Operate in the dark throughout the process and store in the dark at 4°C for standby.

[0053] The ultraviolet-visible spectrophotometer for determining the total carotenoid content measures the absorbance values at wavelengths of A470, A665, and A720 respectively, and calculates the total carotenoid content using the following formulas (1) and (2):

[0054] Chla (mg / L) = 12.945(A665 - A720) (1)

[0055] Car (mg / L) = [1000(A470 - A720) - 2.86Chla] / 221 (2)

[0056] The total carotenoid content obtained by the above method is 0.8 - 1.2 mg / mL.

[0057] 2. Secondly, encapsulate the total carotenoid with liposomes. Dissolve the extracted total carotenoid, egg yolk lecithin, and cholesterol in ethanol together (the mass ratio of total carotenoid, egg yolk lecithin, and cholesterol is 1:20:4), and ultrasonically treat it to completely dissolve. The content of total carotenoid in the ethanol solution is 0.3 mg / mL. Then, slowly inject the above solution into the pre-warmed deionized water (the volume ratio of ethanol to deionized water is 1:10) with a syringe equipped with a No. 5 needle, and heat and stir in a water bath until the ethanol in the solution completely volatilizes to obtain a total carotenoid liposome suspension, which is stored in the dark at room temperature and named Car-Lip. Determine the encapsulation efficiency by measuring the total carotenoid content and free carotenoid content in the system:

[0058]

[0059] The highest encapsulation efficiency of Car-Lip obtained by the above method can reach 97%.

[0060] 1) The ultraviolet spectrum scan of the liposomes after encapsulation shows ( Figure 1 ): Both free total carotenoid and total carotenoid liposomes have obvious absorption peaks at 460 nm, and this peak is the characteristic absorption peak of total carotenoid. Moreover, there are no other miscellaneous peaks, proving that the extracted total carotenoid has high purity and no impurities. Compared with free total carotenoid, the peak value of the absorption peak of the liposomes after encapsulation at 460 nm has a significant decrease, which is because the total carotenoid enters the liposomes and affects the absorption peak value.

[0061] 2) The morphologies of blank liposomes and liposomes encapsulating total carotenoid at 100 nm and 600 nm are as Figure 2As shown, both present smooth spherical shapes on the surface, and their size distributions are non-uniform. The particle size of the liposomes encapsulating total carotenoids is significantly larger than the diameter of the blank liposomes. This is attributed to the fact that the molecular chain length of β-carotene, which accounts for the majority in the total carotenoids of Spirulina, is greater than the thickness of the hydrophobic region of the liposome bilayer. Therefore, their arrangement in the liposome must be inclined, with a certain angle between them and the membrane, which expands the hydrophobic region of the liposome bilayer, thus causing an increase in the particle size of the liposomes after encapsulation.

[0062] 3) Antioxidant activity. The antioxidant ability of natural total carotenoids can be attributed to its unique conjugated double bond structure, which enables it to inhibit singlet oxygen or the activity of free radicals, and thus can play a role in protecting human cells and tissues from oxidative damage. The antioxidant activity of Car-Lip was evaluated by its scavenging ability against ABTS and DPPH free radicals.

[0063] Determination of the ability of Car-Lip to scavenge DPPH free radicals: The free total carotenoids and Car-Lip were diluted to appropriate concentrations. A 7.4 mmol / L ABTS ethanol solution and a 2.6 mmol / L K2S2O8 stock solution were prepared. The prepared ABTS stock solution and K2S2O8 stock solution were mixed in equal volumes and allowed to react in the dark for 12 hours, and then diluted with phosphate buffer to an absorbance A of 0.7 ± 0.02 at 734 nm to prepare the ABTS working solution for use.

[0064] Take 0.8 mL of the ABTS working solution, add 0.2 mL of 95% ethanol solution, shake for 10 s to mix well, let stand in the dark for 6 min, and then measure the absorbance value A0 at 734 nm. Take another 0.8 mL of the ABTS working solution, add 0.2 mL of the test solution, shake for 10 s to mix well, let stand in the dark for 6 min, and measure the absorbance value A at 734 nm. The calculation formula for the ABTS free radical scavenging rate is as follows:

[0065]

[0066] Determination of the ability of Car-Lip to scavenge DPPH free radicals: The free total carotenoids and Car-Lip solutions were diluted to appropriate concentrations respectively, and a 0.1 mmol / L DPPH ethanol solution was prepared and stored in the dark for use.

[0067] Solution Ⅰ: Take 2 mL of free total carotenoids and Car-Lip solutions with different concentrations respectively, add 2 mL of DPPH ethanol solution, mix well, and react at room temperature in the dark for 30 min. Measure the absorbance value D1 at 517 nm.

[0068] Solution II: Another 2 mL of ethanol solution and 2 mL of DPPH ethanol solution were mixed, and the absorbance D2 was measured at 517 nm.

[0069] Solution III: 2 mL of free total carotenoids and Car-Lip solutions with different concentrations were taken, and 2 mL of ethanol was added to each. The absorbance D3 was measured at 517 nm.

[0070] The calculation formula for the DPPH radical scavenging rate is as follows:

[0071]

[0072] The ABTS experiment results showed ( Figure 3 ), after encapsulating total carotenoids in liposomes, the ABTS radical scavenging rate was improved compared with free total carotenoids, and the same result was shown in the DPPH radical scavenging rate experiment. The higher antioxidant capacity of liposome-encapsulated total carotenoids than free total carotenoids may be because the solubility and dispersibility of total carotenoids in aqueous solution are improved after being encapsulated in liposomes. In addition, the antioxidant capacity of total carotenoids encapsulated in liposomes is also related to their binding position in the membrane. Spirulina total carotenoids can arrange across the phospholipid membrane, which also improves their ability to react with ABTS and DPPH radicals in the membrane plane.

[0073] 4) In this study, egg yolk lecithin was selected for liposome preparation. Compared with soybean lecithin, egg yolk lecithin has better antioxidant capacity due to its higher saturated fatty acid content. However, due to the presence of unsaturated double bonds, it is still easily oxidized to hydroperoxides and other secondary oxidation products, accompanied by the cleavage of lipid acyl chains, thus affecting the stability of the lipid bilayer. In addition, during liposome preparation, egg yolk lecithin may be affected by external factors such as light, temperature, and metal ions, accelerating the peroxidation process.

[0074] The change in the content of malondialdehyde caused by the reaction of thiobarbituric acid with malondialdehyde (TBARS) can reflect the secondary oxidation degree of the sample. Referring to the method in the literature and making slight improvements, free total carotenoids and Car-Lip solutions were diluted to appropriate concentrations respectively.

[0075] Prepare the TCA-TBA solution: Weigh 30 g of trichloroacetic acid (TCA) and 0.75 g of thiobarbituric acid, take 4.75 mL of concentrated hydrochloric acid and dissolve it in deionized water, ultrasonically treat and stir to make it fully dissolve, and then make the volume up to 250 mL after cooling.

[0076] Take 1 mL of the sample to be tested, and add 1 mL of 0.065 g / mL ferric chloride solution and 1 mL of 0.07 g / mL ascorbic acid solution respectively, and mix well. Place it in a 37 °C water bath and store it away from light for 60 min. Then add 5 mL of TCA-TBA solution respectively and place it in a 100 °C boiling water bath for 10 min. Quickly cool it to room temperature in an ice bath, centrifuge and filter. Take the supernatant and measure its absorbance at a wavelength of 535 nm, denoted as Az. Use deionized water to replace the ferric chloride and ascorbic acid solutions for the blank control experiment, and measure its absorbance at a wavelength of 535 nm, denoted as Ae.

[0077] The calculation formula for the change rate of TBARS is as follows:

[0078]

[0079] From Figure 4 It can be seen that the anti-peroxidation ability of all-carotenoid liposomes varies with different concentrations. The increase in the content of all-carotenoids enhances the inhibitory ability of liposomes against TBARS. However, when exceeding the corresponding concentration range, the inhibition rate of liposomes against TBARS decreases significantly. Combining with the encapsulation rate of all-carotenoid liposomes, the inhibitory effect of all-carotenoids on lipid peroxidation slows down the oxidation process of egg yolk lecithin, maintains the integrity of the liposome membrane structure, enables it to have a good retention ability for the encapsulated all-carotenoids, and there is a significant synergistic protection effect between all-carotenoids and the lecithin membrane.

[0080] 5) Conduct in vitro simulated digestion on free all-carotenoids and Car-Lip respectively. The concentration of all-carotenoids in the gastrointestinal tract determines its bioavailability. The test method is as follows:

[0081] Preparation of simulated gastric juice: Weigh 2 g of NaCl, 7 mL of HCl and 3.2 g of pepsin, dissolve them in 1 L of water, and adjust the pH to 1.2.

[0082] Preparation of simulated intestinal juice:

[0083] i. Preparation of SIF stock solution: 36.667 g / L CaCl2·2H2O, 219.133 g / L NaCl. [[ID=**24**]]

[0084] ii. Bile salt solution: Dissolve 0.1857 g of bile salt in 3.5 mL of PBS, prepare it 24 h in advance, stir and dissolve at room temperature and preheat it at 37 °C for 10 min before digestion.

[0085] iii. Enzyme solution: Dissolve 0.12 g of lipase in 5 mL of PBS, dissolve it at room temperature 40 min before digestion and preheat it at 37 °C for 10 min before use.

[0086] In the gastric digestion stage, free total carotenoids and Car-Lip with the same concentration were mixed with simulated gastric juice at a ratio of 1:1 (v / v). The pH was adjusted to 2.5 with 1 mol / L NaOH solution, and the mixture was placed in a thermostatic shaker pre-warmed to 37 °C and stirred at 100 r / min for 2 h. In the intestinal digestion stage, the SIF stock solution was pre-warmed for 10 min. 30 mL of the digestion product from the gastric stage was taken and the pH was adjusted to 6.99. 1.5 mL of the pre-warmed SIF and 3.5 mL of the bile salt solution were added respectively, and the pH was adjusted to 6.99. 2.5 mL of the pre-warmed lipase solution was quickly added, and the mixture was placed in a thermostatic shaker pre-warmed to 37 °C and stirred at 100 r / min for 2 h. During this period, the pH was kept constant at 7.0, and samples were taken every 20 min.

[0087] After gastric juice digestion, the dissolution rate of free total carotenoids was 16.27 ± 0.43%, and the dissolution rate of Car-Lip was 33.58 ± 0.37% (after the end of gastric digestion and before the start of intestinal digestion). As Figure 5 shown, during intestinal digestion, the digestion rate of free total carotenoids changed little, with a maximum of 26.32 ± 1.86%. The digestion rate of Car-Lip accelerated after 40 min of intestinal digestion and basically ended after about 80 min. The final bioavailability of Car-Lip was up to 67.51 ± 0.42%. This may be because the lipophilicity of total carotenoids limits their dissolution rate and utilization in the aqueous environment of the human digestive system. After encapsulation in liposomes, total carotenoids have good water solubility, thus improving their solubility and utilization in the human digestive system. After the intestinal digestion stage, the release rate of total carotenoids in liposome encapsulation increased significantly, probably due to the decomposition of liposomes loaded with total carotenoids into smaller particles and the dissociation of liposomes in intestinal fluid, which promoted the release of total carotenoids. In addition, the micelles and bile salts present in simulated intestinal fluid also promoted the dissolution of total carotenoids.

[0088] 3. Preparation of Spirulina total carotenoid liposome hydrogel. Liposome gels were prepared by the cross-linking of sodium alginate and calcium ions. Hydrogel beads were prepared with the addition amounts of liposome suspension being 0%, 25%, 50%, 75%, and 100% respectively. After diluting the liposome suspension with water to the corresponding concentration, sodium alginate was added at ratios of 1% and 2% (calculated according to the proportion of the entire final solution system), and the mixture was stirred on a magnetic stirrer for more than 90 min until the sodium alginate was completely dissolved. It was left standing for 60 min until the bubbles in the solution completely disappeared. The above solutions were respectively and uniformly dropped into 2% and 5% calcium lactate solutions with a syringe for cross-linking. After cross-linking, they were washed three times with deionized water and stored in a sealed manner at 4 °C for later use, named Car-Lip-hy.

[0089] 1) Scanning electron microscopy

[0090] The microstructures of blank hydrogel (B-hy), blank liposome hydrogel (Lip-hy), and liposome hydrogel embedded with total carotenoids (Car-Lip-hy) were observed by scanning electron microscopy, as Figure 6 shown (test conditions: hydrogel beads were prepared with a liposome suspension addition of 75%, 2% sodium alginate was added, and the calcium lactate concentration was 5%). The electron microscopy results showed that the structure of B-hy was arranged uniformly and densely. After adding liposomes, the two long hydrocarbon chains of egg yolk lecithin broke the dense structure crosslinked by sodium alginate and calcium ions, but the two long hydrocarbon chains of egg yolk lecithin were arranged parallel and regularly. Figure 6 Figure C shows that the addition of total carotenoids caused molecular binding in the long hydrocarbon chains of egg yolk lecithin that were originally arranged parallel and regularly, indicating that the binding position of total carotenoids in the system was mainly concentrated in the hydrophobic tail of egg yolk lecithin, while the binding site of sodium alginate was mainly in the head position where P was located in egg yolk lecithin. Therefore, it is not difficult to conclude that egg yolk lecithin exists in the system in a pivotal manner and is arranged regularly, connecting the total carotenoid and sodium alginate molecules well.

[0091] 2) X-ray diffraction analysis (XRD)

[0092] The XRD patterns of the three samples of B-hy, Lip-hy, and Car-Lip-hy are as Figure 7 shown (test conditions: hydrogel beads were prepared with a liposome suspension addition of 25%, 2% sodium alginate was added, and the calcium lactate concentration was 5%). It can be seen from the figure that the cross-linking of sodium alginate and calcium ions to form a hydrogel showed a relatively broad diffraction peak at 2θ = 20.88°, and the peak formed a diffuse shape with low intensity, mainly due to the polar interactions within and between sodium alginate molecules, indicating that the hydrogel formed by the cross-linking of sodium alginate and calcium ions had a certain crystalline structure but a low crystallinity. Compared with the diffraction peak of B-hy, the diffraction peak of Lip-hy shifted to the left, and there was a strong diffraction peak at 2θ = 20.0°. The increase in peak intensity may be related to the promotion of the process of forming a hydrogel by the cross-linking of calcium ions with sodium alginate by the liquid crystal state - crystalline state structure of egg yolk lecithin. When the liposome was further embedded with total carotenoids, the diffraction peak of Lip-hy shifted to the right, and there was an obvious diffraction peak at 2θ = 21.1°, but the peak intensity was lower than that of Lip-hy. When forming a hydrogel by cross-linking with calcium ions, the addition of total carotenoids may have played the role of a modifier, and the amount of amorphous substances in the system increased, resulting in a weaker crystallinity.

[0093] 3) X-ray photoelectron spectroscopy analysis (XPS)

[0094] X-ray photoelectron spectroscopy analysis is as Figure 8As shown (test conditions: hydrogel beads were prepared with a liposome suspension addition of 25%, 2% sodium alginate was added, and the calcium lactate concentration was 5%), where Figure 8 A is the XPS full spectrum of the preparation material. It can be found from the figure that it is composed of elements such as C, O, and Ca. The O1s spectrum of XPS is as Figure 8 shown in B. The diffraction peaks at 531.23 eV and 532.43 eV are attributed to C-O and -OH respectively. Figure 8 C is the narrow scan spectrum of Ca 2p. According to the fitting results, the peaks at the positions of 347.66 eV and 351.33 eV correspond to the Ca 2p3 / 2 and Ca 2p1 / 2 orbits, indicating that Ca exists in the +2 valence form in the three groups of samples. After adding liposomes encapsulating all - carotenoids, the Ca binding energy decreased significantly, indicating that the addition of all - carotenoids may promote the approach of Ca and P, resulting in electron transfer and thus reducing the binding energy. Figure 8 D is the narrow scan spectrum of P 2p. The P element was not observed in the B - hy sample. Due to the addition of egg yolk lecithin, diffraction peaks of P appeared. The diffraction peaks at the positions of 133.36 eV and 134.31 eV are caused by the P 2p3 / 2 and P 2p1 / 2 orbits respectively. After adding liposomes encapsulating all - carotenoids, the binding energy decreased, further proving the above speculation and indicating that a chemical bond may be formed between all - carotenoids and lecithin. The XPS results show that the binding of all - carotenoids to liposomes occurs at the hydrophobic tail of lecithin, which also promotes the binding of sodium alginate to the head of lecithin, thus forming a stable structure connected by lecithin as a bridge, strengthening the gel structure and the stability of all - carotenoid encapsulation.

[0095] Example 2: Preparation of Gel Gummy Containing Spirulina All - Carotenoids

[0096]

[0097] (1) Prepare liposomes from all - carotenoids extracted from spirulina (the method is the same as steps 1 and 2 of Example 1);

[0098] (2) Adjust the pH of freshly squeezed pear juice to 6.8 ( Figure 11 Since freshly squeezed fruit juice has a low sugar content, the sugar addition amount is 15%. For commercially available fruit juices such as Tropicana grape juice, the sugar addition amount can be reduced to about 5%). Filter through a filter membrane and add 2% sodium alginate by the mass of the juice for gelation (the sugar - boiling temperature is 80°C);

[0099] (3) Mix the prepared liposome suspension with the juice - sodium alginate solution (the addition amount of the all - carotenoid liposome suspension is 20% of the mass of the juice) and ensure that sodium alginate is completely dissolved. Let it stand for more than 2 hours to completely eliminate the bubbles.

[0100] (4) Use a syringe to slowly and uniformly drip the above solution into a calcium lactate solution with a concentration of 4% for crosslinking. The crosslinking time is 5 min to reach the optimal crosslinking strength. After crosslinking, wash three times with pure water to obtain gel gummies, and control the total carotenoid content in the final product to be 1.2% ± 0.2%.

[0101] Product performance test:

[0102] 1) High-temperature stability of liposomes

[0103] Due to the sugar-boiling process in the preparation process, the liposomes prepared need to maintain their structural integrity at high temperatures and ensure the protection of total carotenoids at high temperatures. The results are as Figure 9 shown. When heated at 25 - 100 °C for 30 - 60 min, the encapsulation rate of liposomes for total carotenoids can remain unchanged, achieving a good high-temperature resistance effect.

[0104] 2) Gummy texture

[0105] Use a TA-TX type texture analyzer for TPA measurement, and perform two compressions. The maximum resistance of the first compression is used to represent the hardness of the sample, and the displacement difference between the sample during the second compression and before the start of the second compression is used to represent the elasticity of the sample. The texture conditions are shown in Table 1, and the TPA and breakage test results of the filled gummies are shown in Table 2.

[0106] Table 1 Texture conditions

[0107]

[0108] Table 2 TPA and breakage of filled gummies

[0109]

[0110]

[0111] 3) pH and water activity

[0112] Test method for water activity: Place a dry tray on the water activity meter and zero it. Weigh filled gummies and three similar commercially available gummies of the same mass and place them on the tray in turn. After covering the lid, perform the water activity measurement. Among them, the three commercially available gummies are named commercially available gummy 1 (QQ gummy), commercially available gummy 2 (juice burst gummy), and commercially available gummy 3 (crystal ball crispy bobble).

[0113] pH measurement: After melting the commercially available gummy candies, take 10 g of the melted solution, mix it evenly with 10 mL of distilled water, and measure its pH with a pH meter. However, since the cross-linking process of the core-injected gummy candies does not affect their pH, 10 g of the solution before cross-linking with calcium lactate can be taken, mixed evenly with 10 mL of distilled water, and its pH can be measured. Among them, the commercially available product 3 cannot be melted, so its pH value cannot be measured.

[0114] The results of water activity and pH are shown in Table 3.

[0115] Table 3 Comparison of pH and water activity between core-injected gummy candies and commercially available gummy candies

[0116]

[0117] 4) Anti-deformation rate

[0118] Test method for anti-deformation rate: Select 3 groups of samples of core-injected gummy candies, commercially available gummy candy 1, commercially available gummy candy 2, and commercially available gummy candy 3 with the same shape and weight, and measure the height of each sample before heat preservation and record it as H1. Place the samples to be tested horizontally in a constant temperature and humidity chamber at 35 °C for 48 h, and measure the height of each sample after heat preservation and cooling and record it as H2. The calculation formula for the anti-deformation rate is shown in (7):

[0119]

[0120] The test results of the anti-deformation rate are as Figure 10 shown.

[0121] 5) Melting property

[0122] Test method for melting property: Weigh the core-injected gummy candies, commercially available gummy candy 1, commercially available gummy candy 2, and commercially available gummy candy 3 with the same mass and cut them into cylindrical shapes, place them in a covered glass petri dish, treat them in an oven at 220 °C for 5 min, take them out and let them cool at room temperature for 30 min. Each time, use a marker pen to mark along the edge of the gummy candy sample on the back of the glass petri dish before and after melting for measuring the diameter. The diameter should be measured at 5 different points and the average value should be taken. Calculate the percentage increase in diameter, and conduct three parallel tests for each sample.

[0123] The results are shown in Table 4.

[0124] Table 4 Comparison of melting properties between core-injected gummy candies and commercially available gummy candies

[0125]

[0126] 6) Product pictures

[0127] The product pictures are as Figure 11 shown, the product has a good form and good bursting performance.

[0128] The experimental results show that the gummy candies of the present invention have good texture characteristics. Compared with commercially available gummy candies, containing all carotenoids makes them have higher nutritional value, the pH is roughly neutral, the water activity is high and the water content is relatively high, the anti-deformation rate is at the average level of commercially available products, and it has the characteristic of high temperature resistance higher than all commercially available products, and it can be made not to melt at high temperatures.

[0129] Example 3: Preparation of jelly containing Spirulina all-carotenoids

[0130] (1) Prepare a carotenoid liposome suspension from all-carotenoids extracted from Spirulina (Method Example 1);

[0131] (2) Adjust the pH of the fruit juice to 6.8 (the sugar addition amount is determined according to the sweetness of different fruit juices), and add 1.5% of sodium alginate based on the mass of the fruit juice for gelatinization (temperature 80°C);

[0132] (3) Mix the prepared all-carotenoid liposome suspension with the fruit juice sodium alginate solution (the addition amount of the all-carotenoid liposome suspension is 20% of the mass of the fruit juice) and ensure that the sodium alginate is completely dissolved, and let it stand for more than 2 hours to completely eliminate the bubbles;

[0133] (4) Slowly and evenly pour the prepared 2% calcium lactate solution along the wall of the cup into the sodium alginate liposome mixed fruit juice solution, and let it stand waiting for crosslinking. The crosslinking time of 30 minutes reaches the optimal crosslinking degree.

[0134] Example 4: Preparation of facial mask essence containing Spirulina all-carotenoids

[0135] (1) Prepare a liposome suspension from all-carotenoids extracted from Spirulina (the same as Steps 1 and 2 of Example 1). Add 1% of sodium alginate to the carotenoid liposome suspension at 80°C and stir until the sodium alginate is completely dissolved;

[0136] (2) Add 20% glycerol and 3% propylene glycol, and homogenize and emulsify. Cool down and adjust the pH to 6.8;

[0137] (3) Filter with a 300-mesh filter cloth, and then let it stand for 24 hours to obtain the primary product facial mask essence, with the all-carotenoid content of 0.03 mg / mL;

[0138] (4) Soak the facial mask paper and it can be used.

Claims

1. Preparation process of a high-temperature resistant core-injected gel product containing Spirulina total carotenoids, characterized in that (1) Extraction of Spirulina total carotenoids Adding Spirulina powder to methanol for cell wall breaking, and then carrying out saponification, extraction, and rotary evaporation for total carotenoid extraction; (2) Liposome encapsulation of total carotenoids Dissolving the extracted total carotenoids, egg yolk lecithin, and cholesterol in ethanol together, and performing ultrasonic treatment to completely dissolve them; then slowly injecting into water and heating and stirring in a water bath until the ethanol in the solution completely volatilizes to obtain a total carotenoid liposome suspension; (3) Preparation of Spirulina total carotenoid liposome hydrogel product Based on the cross-linking effect of sodium alginate and calcium ions, a high-temperature resistant gel product capable of carrying total carotenoid liposomes is obtained; the high-temperature resistant gel product is core-injected gel gummies, core-injected gel jelly, or a facial mask; The preparation process of the core-injected gel gummies is as follows: Prepare the fruit juice, add sodium alginate for gelatinization, and after gelatinization, add the obtained sodium alginate fruit juice solution to the total carotenoid liposome suspension, stir until the sodium alginate is completely dissolved, and then let it stand until the bubbles completely disappear; then uniformly drip the above solution into an aqueous solution containing calcium ions for cross-linking for 4 - 6 minutes to reach the optimal cross-linking degree, and after washing with pure water, the core-injected gel gummies are obtained; The preparation process of the core-injected gel jelly is as follows: Prepare the fruit juice, add sodium alginate for gel gelatinization, mix it with the total carotenoid liposome suspension after gelatinization and ensure that the sodium alginate is completely dissolved, and then let it stand to completely eliminate the bubbles; slowly and uniformly add a calcium ion solution to the above solution, and let it stand and wait for cross-linking for 30 - 40 minutes to reach the optimal cross-linking degree to obtain the core-injected gel jelly; The preparation process of the facial mask is as follows: Add sodium alginate to the total carotenoid liposome suspension preheated to 70 - 90 °C, stir until the sodium alginate is completely dissolved; then add glycerol and propylene glycol, homogenize and emulsify, cool down, adjust the pH to 6.5 - 7.0, and then filter and let it stand to obtain the primary product facial mask essence; soak the facial mask paper to obtain it.

2. The preparation process of the high-temperature resistant core-injected gel product according to claim 1, characterized in that, In step (1), The cell wall breaking is: adding Spirulina powder to methanol and placing it in a magnetic stirrer for cell wall breaking; The saponification is: centrifuging the cell wall broken suspension, filtering the supernatant, adding potassium hydroxide and placing it on a magnetic stirrer for saponification; centrifuging the saponified solution, and filtering the obtained supernatant; The extraction is: extracting the saponified solution in petroleum ether, and washing the upper layer of the extraction solution with ultrapure water until no green is washed out.

3. The preparation process of the high-temperature resistant core-injected gel product according to claim 1, characterized in that, In step (2), the mass ratio of total carotenoids, egg yolk lecithin, and cholesterol is 1:15 - 20:3 - 5.

4. The preparation process of the high-temperature resistant core-injecting gel product as described in claim 1, characterized in that, In the preparation process of the core-injected gel gummies: based on the mass of the fruit juice, the addition amount of the total carotenoid liposome suspension is 15% - 25%, and the dosage of sodium alginate is 1.8 - 2.2%; the aqueous solution containing calcium ions is calcium lactate with a concentration of 3% - 5%.

5. The preparation process of the high-temperature resistant core-injected gel product as described in claim 1 is characterized in that, In the preparation process of the core-injected gel jelly, based on the mass of the fruit juice, the addition amount of the total carotenoid liposome suspension is 15% - 25%, and the dosage of sodium alginate is 1.2 - 1.8%; the calcium ion solution is calcium lactate, and the concentration is 1.8 - 2.2%.

6. The preparation process of the high-temperature resistant core-injected gel product according to claim 1, characterized in that, In the preparation process of the facial mask, the addition amount of sodium alginate is 0.8% - 1.0% of the total carotenoid liposome suspension.

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