A high-stability DHA emulsion and its preparation method and application

Abstract

The present invention relates to the technical field of food processing, and in particular to a highly stable DHA emulsion, a preparation method thereof and an application thereof. The DHA emulsion comprises: DHA algae oil and water; in terms of mass percentage, the DHA content in the DHA emulsion is 4-40%, the oil loading amount of the DHA emulsion is 20-56%, and the oleic acid in the DNA emulsion accounts for 4-61% of the total oil content. The present invention has found that by selecting DHA algae oil with a high oleic acid content as a raw material, or adding high oleic acid content oil to the DHA emulsion, the appearance stability and sensory stability of the prepared DHA emulsion can be significantly improved, thereby improving the stability of the DHA-containing liquid product and the net content of DHA, which is of great significance in the field of food processing.

Description

Technical Field

[0001] The invention relates to the technical field of food processing, and in particular to a high-stability DHA emulsion and a preparation method and application thereof. Background Art

[0002] DHA, docosahexaenoic acid, commonly known as brain gold, is a polyunsaturated fatty acid that is very important to the human body and is an important member of the Omega-3 unsaturated fatty acid family. DHA is essential for brain development and visual formation, and has significant effects on enhancing memory and thinking ability, improving intelligence, etc. At the same time, DHA also has a great impact on metabolic regulation, cardiovascular and cerebrovascular diseases, immune function, and Alzheimer's disease. In the human body, DHA can be synthesized from linolenic acid, but the conversion rate is extremely low, so the DHA required by the human body is mainly ingested through diet. The main sources of DHA are fatty fish, algae, egg yolk, breast milk, etc. Among them, DHA algae oil, as a high-quality source of DHA, has shown a broadening trend in the field of health foods and the expansion of adult health foods.

[0003] DHA has six unsaturated double bonds in its chemical structure, which is very easy to be oxidized. The fishy smell and rancidity produced by its oxidation reaction will greatly affect consumers' acceptance of the product; DHA is incompatible with water. When added to water-based products such as liquid milk and beverages, it needs to be emulsified to form an oil-in-water emulsion system. The DHA oil is wrapped by an emulsifier, which significantly reduces the contact area with oxygen and avoids the oxidation of DHA to produce fishy smell and rancidity. However, the emulsion is a thermodynamically unstable system, because the liquid-liquid system has a natural tendency to separate and reduce its interfacial energy. The stability of the emulsion can be defined as the ability of the system to resist changes in physical and chemical properties over time. Therefore, the requirements for the formula and its process of the highly stable emulsion are very high, otherwise DHA is more likely to be oxidized, more likely to produce fishy smell or rancidity. Therefore, DHA is rarely used in liquid products or the addition amount is very low, so that the product cannot achieve the nutritional and health care effect. At present, the main application areas of DHA are soft capsules / gel candies, solid beverages, milk powder and other products, but there are deficiencies such as the need to take extra rubber, add flavors or poor flavor, and inconvenience in eating. Liquid products have the characteristics of rich product types, convenient consumption, and multiple consumption scenarios. If DHA can be used in more liquid products, the DHA application consumer market will be further expanded.

[0004] In order to improve the stability of the emulsion, the researchers found that when the lipophilic group of the emulsifier used has the same or similar polarity as the oil to be emulsified, the emulsification effect is better and the stability of the emulsion is increased. However, polyunsaturated fatty acids are expensive, unstable, and have poor sensory perception after oxidation. The development of emulsifier products with polyunsaturated fatty acids as lipophilic groups is difficult, costly, and unstable. Currently, there are no emulsifiers with polyunsaturated fatty acids as lipophilic groups on the market. Therefore, the above-mentioned preparation method for improving the stability of the emulsion is not suitable for DHA emulsions. There is an urgent need for a preparation method for a highly stable DHA emulsion to meet various application scenarios.

[0005] Patent CN117837745A discloses an acid, alkali and salt resistant heat-stable high-oil-carrying emulsion and a preparation method thereof, but the formula also contains a high content of propylene glycol. Propylene glycol has a good emulsifying effect and can significantly improve the stability of the emulsion. However, propylene glycol is only allowed to be used in 06.03.02.01 (raw wet noodle products) and 07.02 (cakes) in the GB 2760-2024 National Food Safety Standard for Food Additives, which severely limits its application; Patent CN101259102B discloses a micron-level docosahexaenoic acid emulsion and a preparation method thereof. The DHA emulsion prepared in the patent is described as a thermodynamically stable emulsion, but in fact, it is generally recognized by the academic community that emulsions are generally thermodynamically unstable systems, and it does not provide any data and proof of the stability of the DHA emulsion prepared and the stability of the applied product. Therefore, the emulsion prepared by the patent is not widely recognized and is difficult to be applied to liquid DHA-containing products. Summary of the invention

[0006] In order to solve the problems existing in the prior art, the present invention provides a DHA emulsion and a preparation method and application thereof.

[0007] The present invention has found in a large number of studies that the use of high oleic acid DHA algae oil to prepare DHA emulsion, or the addition of high oleic acid oil to DHA emulsion can effectively improve the stability of DHA emulsion (including appearance stability and sensory stability), and thus more DHA can be added to the liquid DHA product, and the obtained product has a higher nutritional value.

[0008] In a first aspect, the present invention provides a DHA emulsion, comprising: DHA algae oil and water; in terms of mass percentage, the DHA content in the DHA emulsion is 4-40%, the oil loading amount of the DHA emulsion is 20-56%, and the oleic acid in the DNA emulsion accounts for 4-61% of the total oil content.

[0009] Furthermore, in terms of mass percentage, the DHA content in the DHA emulsion is 8-40%, the oil loading amount of the DHA emulsion is 40-52%, and the content of oleic acid in the DHA emulsion accounts for 9.0-46.0% of the total oil.

[0010] Further, the emulsifier includes an oil phase emulsifier and a water phase emulsifier; The oil phase emulsifier includes: one or more of mono- and di-glycerides, sucrose fatty acid esters, citric acid glycerol fatty acid esters, sorbitan monolaurate, sorbitan monopalmitate, sorbitan tristearate, sorbitan monooleate, propylene glycol fatty acid esters, succinic acid monoglyceride, polyglycerol ricinoleate or lactic acid fatty acid glyceride; The aqueous phase emulsifier includes: one or more of sucrose fatty acid ester, polyglycerol fatty acid ester, modified soybean lecithin, sodium octenyl succinate starch, polyoxyethylene (20) sorbitan monolaurate, polyoxyethylene (20) sorbitan monostearate, polyoxyethylene (20) sorbitan monooleate or polyoxyethylene (20) sorbitan monopalmitate.

[0011] Further, the antioxidant includes: an oil phase antioxidant and a water phase antioxidant; The oil phase antioxidant comprises: one or more of rosemary extract, vitamin E, theaflavin, BHA, BHT, ascorbyl palmitate, propyl gallate or TBHQ; The water phase antioxidant includes: one or more of D-isoascorbic acid, sodium D-isoascorbate, ascorbic acid or sodium ascorbate.

[0012] Furthermore, the auxiliary emulsifier is glycerol, and the flavoring agent is one or more of trehalose, lactose or maltodextrin.

[0013] As a preferred embodiment, the present invention provides a DHA emulsion, which comprises, by weight: 30-50 parts of DHA algae oil, 0.02-0.1 parts of oil phase antioxidant, 0.2-1 parts of oil phase emulsifier, 0.1-1 parts of water phase antioxidant, 0.5-2 parts of water phase emulsifier, 1-10 parts of auxiliary emulsifier, 2-15 parts of flavoring agent, 40-50 parts of water; the DHA content of the DHA algae oil is ≥40%, and the oleic acid content is ≥12%.

[0014] As a preferred embodiment, the present invention provides a DHA emulsion, which comprises, by weight: 20-50 parts of DHA algae oil, 2-30 parts of high oleic sunflower oil, 0.01-0.1 parts of phase antioxidant, 0.1-1 parts of oil phase emulsifier, 0.1-3 parts of water phase antioxidant, 0.5-3 parts of water phase emulsifier, 1-10 parts of co-emulsifier, 2-15 parts of flavoring agent, 25-50 parts of water; the DHA content of the DHA algae oil is ≥40%, and the oleic acid content is ≤2%; the oleic acid content of the high oleic sunflower oil is ≥75%.

[0015] In a second aspect, the present invention provides a method for preparing the DHA emulsion, comprising: DHA algae oil, oil phase antioxidant, and oil phase emulsifier are mixed according to a predetermined ratio, and fully sheared to obtain an oil phase; Mixing an aqueous phase antioxidant, an aqueous phase emulsifier, an auxiliary emulsifier, a flavoring agent and water in a predetermined ratio, and fully shearing to obtain an aqueous phase; Mixing the oil phase and the water phase under continuous shearing to obtain a primary emulsion; The primary emulsion is homogenized under high pressure to obtain a DHA emulsion.

[0016] Furthermore, the method further comprises: sterilizing the DHA emulsion and then aseptically filling it to obtain a finished DHA emulsion.

[0017] Furthermore, the conditions for sufficient shearing are as follows: shearing for 3 to 5 minutes at 30 to 40° C. and 5000 to 8000 rpm / min.

[0018] Furthermore, the continuous shearing conditions are as follows: continuous shearing for 10 to 20 minutes at 30 to 40° C. and 5000 to 8000 rpm / min.

[0019] In a third aspect, the present invention provides a method for improving the stability of a DHA emulsion, comprising: The DHA emulsion is prepared by using DHA algae oil with high oleic acid content, or, The oleic acid content in the DHA emulsion is increased.

[0020] Furthermore, the oleic acid content of the high oleic acid DHA algae oil is ≥12%, preferably derived from Schizochytrium CABIO-A-2-VI, the deposit number of Schizochytrium CABIO-A-2-VI is CCTCC NO: M 2024961; and / or, increasing the oleic acid content in the DHA emulsion is: increasing the oleic acid content to more than 9% of the total oil in the DHA emulsion.

[0021] The preservation information of Schizochytrium sp. CABIO-A-2-VI is as follows: Preservation number: CCTCC NO: M 2024961; Classification name: Schizochytrium sp. CABIO-A-2-VI; Preservation unit: China Center for Type Culture Collection; Preservation address: Wuhan University, Wuhan, China; Preservation date: May 15, 2024.

[0022] The method of increasing the oleic acid content to above 9% of the total oil in the DHA emulsion can be achieved by adding other oils with high oleic acid content such as high oleic sunflower oil.

[0023] In a fourth aspect, the present invention provides the use of the DHA emulsion in the preparation of a liquid DHA product; the product comprises: one or more of a nutritional supplement, a functional beverage, a dairy product or a condiment.

[0024] The present invention has the following beneficial effects: The present invention has found that the appearance stability and sensory stability of DHA emulsion can be effectively improved by increasing the content of oleic acid in the oil in the DHA emulsion, for example, using DHA algae oil with a high oleic acid content, or adding oil with a high oleic acid content to the DHA emulsion. The DHA emulsion provided by the present invention has high stability, which can solve the problem of poor sensory properties and low addition amount of DHA in liquid product applications, filling the market gap in this field. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 It is a composition comparison diagram of Examples 1-13 and Comparative Examples 1-6 provided by the present invention; Control Groups 1-6 in the figure correspond to Comparative Examples 1-6. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] The experimental methods involved in the following examples, unless otherwise mentioned, are all conventional methods in the art, for example, reference may be made to experimental manuals in the art, or the conditions recommended in the manufacturer's instructions.

[0029] Unless otherwise specified, the experimental materials and reagents involved in the following examples can be obtained from commercial sources.

[0030] The raw materials used in the following examples: DHA algae oil A (derived from the fermentation of Schizochytrium CABIO-A-2-VI, with a DHA content ≥40%, an oleic acid content ≥12%); DHA algae oil B (DHA content ≥40%, oleic acid content ≤2%); high oleic sunflower oil (oleic acid content ≥75%).

[0031] Example 1 1. Weigh 40 g of DHA algae oil A, 0.05 g of rosemary extract, and 0.1 g of mono- and di-glycerides. Incubate at 30°C, 5000 rpm, and shear for 3 min to obtain the oil phase.

[0032] 2. Weigh 0.2 g of D-isoascorbic acid, 1 g of sucrose fatty acid ester, 2 g of glycerol, 10 g of trehalose, and 46.65 g of deionized water. Incubate at 30°C, 5000 rpm, and shear for 3 min to obtain the aqueous phase.

[0033] 3. Under continuous shearing condition, slowly add the oil phase into the water phase. After the oil and water phases are mixed, shear for 10 min at 30°C and 5000 rpm, and then homogenize twice at 60 MPa to obtain DHA emulsion, which is sterilized and stored.

[0034] 4. Feature 1. The oil content of the emulsion is 40%, Feature 2. The content of oleic acid in the total oil is 12%, Feature 3. The content of pure DHA in the emulsion is 16%.

[0035] Example 2 1. Weigh 40g of DHA algae oil B, 2g of high oleic sunflower oil, 0.05g of vitamin E, and 0.2g of sucrose fatty acid ester (monoester <30%). Incubate at 35°C, 6000rpm, and shear for 4min to obtain the oil phase.

[0036] 2. Weigh 0.5 g of sodium D-isoascorbate, 1.5 g of polyglycerol fatty acid ester, 4 g of glycerol, 8 g of lactose, and 43.75 g of deionized water. Incubate at 35°C, 6000 rpm, and shear for 4 min to obtain the aqueous phase.

[0037] 3. Under continuous shearing condition, slowly add the oil phase into the water phase. After the oil and water phases are mixed, shear for 15 min at 35°C and 6000 rpm, and then homogenize at 70 MPa for 3 times to obtain DHA emulsion, which is sterilized and stored.

[0038] 4. Feature 1. The oil content of the emulsion is 42%, Feature 2. The content of oleic acid in the total oil is 5.5%, Feature 3. The content of pure DHA in the emulsion is 16%.

[0039] Example 3 1. Weigh 40g of DHA algae oil B, 5g of high oleic sunflower oil, 0.04g of theaflavins, and 0.4g of citric acid glycerol fatty acid ester. Incubate at 40°C, 7000rpm, and shear for 5min to obtain the oil phase.

[0040] 2. Weigh 1 g of ascorbic acid, 2 g of polyoxyethylene (20) sorbitan monolaurate, 6 g of glycerol, 6 g of maltodextrin, and 39.56 g of deionized water. Incubate at 40°C, 7000 rpm, and shear for 5 min to obtain the aqueous phase.

[0041] 3. Under continuous shearing condition, slowly add the oil phase into the water phase. After the oil and water phases are mixed, shear for 20 min at 40°C and 7000 rpm, and then homogenize twice at 80 MPa to obtain DHA emulsion, which is sterilized and stored.

[0042] 4. Feature 1. The oil content of the emulsion is 45%, Feature 2. The content of oleic acid in the total oil is 10.1%, Feature 3. The content of pure DHA in the emulsion is 16%.

[0043] Example 4 1. Weigh 40 g of DHA algae oil B, 8 g of high oleic sunflower oil, 0.02 g of BHA, and 0.5 g of sorbitan monolaurate. Incubate at 30°C, 6000 rpm, and shear for 5 min to obtain the oil phase.

[0044] 2. Weigh 2g of sodium ascorbate, 2.5g of polyoxyethylene (20) sorbitan monopalmitate, 8g of glycerol, 2g of trehalose, 2g of lactose, and 34.98g of deionized water. Incubate at 30°C, 6000rpm, and shear for 5min to obtain the aqueous phase.

[0045] 3. Under continuous shearing condition, slowly add the oil phase into the water phase. After the oil and water phases are mixed, shear for 15 min at 30°C and 6000 rpm, and then homogenize twice at 60 MPa to obtain DHA emulsion, which is sterilized and stored.

[0046] 4. Feature 1. The oil content of the emulsion is 48%, Feature 2. The content of oleic acid in the total oil is 14.2%, Feature 3. The content of pure DHA in the emulsion is 16%.

[0047] Example 5 1 Weigh 40g of DHA algae oil B, 12g of high oleic sunflower oil, 0.02g of BHT, and 0.3g of sorbitan monolaurate. Incubate at 30°C, 8000rpm, and shear for 4min to obtain the oil phase.

[0048] 2. Weigh 1 g of ascorbic acid, 1 g of sodium ascorbate, 3 g of polyoxyethylene (20) sorbitan monopalmitate, 10 g of glycerol, 1 g of lactose, 1 g of maltodextrin, and 30.68 g of deionized water. Incubate at 30°C, 8000 rpm, and shear for 4 min to obtain the aqueous phase.

[0049] 3. Under continuous shearing condition, slowly add the oil phase into the water phase. After the oil and water phases are mixed, shear for 15 min at 30°C and 8000 rpm, and then homogenize 3 times at 70 MPa to obtain DHA emulsion, which is sterilized and stored.

[0050] 4. Feature 1. The oil content of the emulsion is 52%, Feature 2. The content of oleic acid in the total oil is 18.9%, Feature 3. The content of pure DHA in the emulsion is 16%.

[0051] Example 6 1. Weigh 40 g of DHA algae oil B, 16 g of high oleic sunflower oil, 0.02 g of ascorbyl palmitate, and 0.2 g of sorbitan monolaurate. Incubate at 35°C, 6000 rpm, and shear for 3 min to obtain the oil phase.

[0052] 2. Weigh 1 g of D-isoascorbic acid, 1 g of sodium D-isoascorbate, 2 g of polyoxyethylene (20) sorbitan monooleate, 1 g of glycerol, 9 g of trehalose, and 29.78 g of deionized water. Incubate at 35°C, 6000 rpm, and shear for 3 min to obtain the aqueous phase.

[0053] 3. Under continuous shearing condition, slowly add the oil phase into the water phase. After the oil and water phases are mixed, shear for 20 min at 35°C and 6000 rpm, and then homogenize twice at 80 MPa to obtain DHA emulsion, which is sterilized and stored.

[0054] 4. Feature 1. The oil content of the emulsion is 56%, Feature 2. The content of oleic acid in the total oil is 22.9%, Feature 3. The content of pure DHA in the emulsion is 16%.

[0055] Example 7 1. Weigh 50 g of DHA algae oil A, 0.01 g of propyl gallate, and 0.5 g of sorbitan tristearate. Incubate at 40°C, 5000 rpm, and shear for 5 min to obtain the oil phase.

[0056] 2. Weigh 0.5 g of D-isoascorbic acid, 2.5 g of modified soybean lecithin, 3 g of glycerol, 7 g of lactose, and 36.49 g of deionized water. Incubate at 40°C, 5000 rpm, and shear for 5 min to obtain the aqueous phase.

[0057] 3. Under continuous shearing condition, slowly add the oil phase into the water phase. After the oil and water phases are mixed, shear for 15 min at 40°C and 5000 rpm, and then homogenize twice at 60 MPa to obtain DHA emulsion, which is sterilized and stored.

[0058] 4. Feature 1. The oil content of the emulsion is 50%, Feature 2. The content of oleic acid in the total oil is 12%, Feature 3. The content of pure DHA in the emulsion is 20%.

[0059] Example 8 1. Weigh 48 g of DHA algae oil B, 2 g of high oleic sunflower oil, 0.02 g of TBHQ, and 0.3 g of sorbitan monooleate. Incubate at 40°C, 5000 rpm, and shear for 3 min to obtain the oil phase.

[0060] 2. Weigh 1 g of sodium D-isoascorbate, 3 g of sodium starch octenylsuccinate, 5 g of glycerol, 5 g of maltodextrin, and 35.68 g of deionized water. Incubate at 40°C, 5000 rpm, and shear for 3 min to obtain the aqueous phase.

[0061] 3. Under continuous shearing condition, slowly add the oil phase into the water phase. After the oil and water phases are mixed, shear for 10 min at 40°C and 5000 rpm, and then homogenize at 70 MPa for 3 times to obtain DHA emulsion, which is sterilized and stored.

[0062] 4. Feature 1. The oil content of the emulsion is 50%, Feature 2. The content of oleic acid in the total oil is 4.9%, Feature 3. The content of pure DHA in the emulsion is 19.2%.

[0063] Example 9 1. Weigh 45 g of DHA algae oil B, 5 g of high oleic sunflower oil, 0.05 g of rosemary extract, 0.05 g of vitamin E, and 0.2 g of propylene glycol fatty acid ester. Incubate at 35°C, 5000 rpm, and shear for 5 min to obtain the oil phase.

[0064] 2. Weigh 2 g of ascorbic acid, 1 g of sucrose fatty acid ester, 1 g of polyglycerol fatty acid ester, 7 g of glycerol, 3 g of trehalose, and 35.7 g of deionized water. Incubate at 35°C, 5000 rpm, and shear for 5 min to obtain the aqueous phase.

[0065] 3. Under continuous shearing condition, slowly add the oil phase into the water phase. After the oil and water phases are mixed, shear for 15 min at 35°C and 5000 rpm, and then homogenize twice at 80 MPa to obtain DHA emulsion, which is sterilized and stored.

[0066] 4. Feature 1. The oil content of the emulsion is 50%, Feature 2. The content of oleic acid in the total oil is 9.3%, Feature 3. The content of pure DHA in the emulsion is 18%.

[0067] Example 10 1. Weigh 40 g of DHA algae oil B, 10 g of high oleic sunflower oil, 0.05 g of vitamin E, 0.02 g of ascorbyl palmitate, and 0.3 g of succinic acid monoglyceride. Incubate at 30°C, 6000 rpm, and shear for 4 min to obtain the oil phase.

[0068] 2. Weigh 2 g of sodium ascorbate, 1.5 g of polyglycerol fatty acid ester, 1.5 g of polyoxyethylene (20) sorbitan monolaurate, 9 g of glycerol, 1 g of lactose, and 34.63 g of deionized water. Incubate at 30°C, 6000 rpm, and shear for 4 min to obtain the aqueous phase.

[0069] 3. Under continuous shearing condition, slowly add the oil phase into the water phase. After the oil and water phases are mixed, shear for 20 min at 30°C and 6000 rpm, and then homogenize twice at 60 MPa to obtain DHA emulsion, which is sterilized and stored.

[0070] 4. Feature 1. The oil content of the emulsion is 50%, Feature 2. The content of oleic acid in the total oil is 16.6%, Feature 3. The content of pure DHA in the emulsion is 16%.

[0071] Embodiment 11 1. Weigh 30 g of DHA algae oil B, 20 g of high oleic sunflower oil, 0.04 g of theaflavins, 0.02 g of BHT, 0.02 g of ascorbyl palmitate, and 0.3 g of polyglycerol ricinoleate. Incubate at 40°C, 7000 rpm, and shear for 3 min to obtain the oil phase.

[0072] 2. Weigh 0.5 g ascorbic acid, 0.5 g sodium ascorbate, 2 g sucrose fatty acid ester, 10 g glycerol, 3 g maltodextrin, and 33.64 g deionized water. Incubate at 40°C, 7000 rpm, and shear for 3 min to obtain the aqueous phase.

[0073] 3. Under continuous shearing condition, slowly add the oil phase into the water phase. After the oil and water phases are mixed, shear for 15 min at 40°C and 7000 rpm, and then homogenize 3 times at 70 MPa to obtain DHA emulsion, which is sterilized and stored.

[0074] 4. Feature 1. The oil content of the emulsion is 50%, Feature 2. The content of oleic acid in the total oil is 31.2%, Feature 3. The content of pure DHA in the emulsion is 12%.

[0075] Example 12 1. Weigh 20g of DHA algae oil B, 30g of high oleic sunflower oil, 0.05g of vitamin E, and 0.5g of lactic acid fatty acid glyceride. Incubate at 30°C, 8000rpm, and shear for 3min to obtain the oil phase.

[0076] 2. Weigh 2 g of D-isoascorbic acid, 1 g of sodium D-isoascorbate, 2.5 g of polyglycerol fatty acid ester, 8 g of glycerol, 5 g of trehalose, and 30.95 g of deionized water. Incubate at 30°C, 8000 rpm, and shear for 3 min to obtain the aqueous phase.

[0077] 3. Under continuous shearing condition, slowly add the oil phase into the water phase. After the oil and water phases are mixed, shear for 10 min at 30°C and 8000 rpm, and then homogenize twice at 80 MPa to obtain DHA emulsion, which is sterilized and stored.

[0078] 4. Feature 1. The oil content of the emulsion is 50%, Feature 2. The content of oleic acid in the total oil is 45.8%, Feature 3. The content of pure DHA in the emulsion is 8%.

[0079] Embodiment 13 1. Weigh 10g DHA algae oil B, 40g high oleic sunflower oil, 0.04g theaflavins, 0.2g mono- and di-glycerides, and 0.3g citric acid glycerol fatty acid esters, and incubate at 35°C, 8000rpm, and shear for 5min to obtain the oil phase.

[0080] 2. Weigh 0.2 g of D-isoascorbic acid, 3 g of polyoxyethylene (20) sorbitan monolaurate, 6 g of glycerol, 7 g of lactose, and 33.26 g of deionized water. Incubate at 35°C, 8000 rpm, and shear for 5 min to obtain the aqueous phase.

[0081] 3. Under continuous shearing condition, slowly add the oil phase into the water phase. After the oil and water phases are mixed, shear for 15 min at 35°C and 8000 rpm, and then homogenize twice at 60 MPa to obtain DHA emulsion, which is sterilized and stored.

[0082] 4. Feature 1. The oil content of the emulsion is 50%, Feature 2. The content of oleic acid in the total oil is 60.4%, Feature 3. The content of pure DHA in the emulsion is 4%.

[0083] Comparative Example 1 1. Weigh 40g of DHA algae oil B, 0.02g of BHA, and 0.3g of sucrose fatty acid ester (monoester <30%), and incubate at 35°C, 7000rpm, and shear for 4min to obtain the oil phase.

[0084] 2. Weigh 0.5 g of sodium D-isoascorbate, 1.5 g of polyoxyethylene (20) sorbitan monopalmitate, 4 g of glycerol, 9 g of maltodextrin, and 44.68 g of deionized water. Incubate at 35°C, 7000 rpm, and shear for 4 min to obtain the aqueous phase.

[0085] 3. Under continuous shearing condition, slowly add the oil phase into the water phase. After the oil and water phases are mixed, shear for 10 min at 35°C and 7000 rpm, and then homogenize at 70 MPa for 3 times to obtain DHA emulsion, which is sterilized and stored.

[0086] 4. Feature 1. The oil content of the emulsion is 40%, Feature 2. The content of oleic acid in the total oil is 2%, Feature 3. The content of pure DHA in the emulsion is 16%.

[0087] Comparative Example 2 1. Weigh 40 g of DHA algae oil B, 20 g of high oleic sunflower oil, 0.02 g of BHT, and 0.3 g of citric acid glycerol fatty acid ester. Incubate at 35°C, 6000 rpm, and shear for 5 min to obtain the oil phase.

[0088] 2. Weigh 1 g of ascorbic acid, 3 g of polyoxyethylene (20) sorbitan monostearate, 2 g of glycerol, 2 g of trehalose, and 31.68 g of deionized water. Incubate at 35°C, 6000 rpm, and shear for 5 min to obtain the aqueous phase.

[0089] 3. Under continuous shearing condition, slowly add the oil phase into the water phase. After the oil and water phases are mixed, shear for 15 min at 35°C and 6000 rpm, and then homogenize at 80 MPa for 3 times to obtain DHA emulsion, which is sterilized and stored.

[0090] 4. Feature 1. The oil content of the emulsion is 60%, Feature 2. The content of oleic acid in the total oil is 26.3%, Feature 3. The content of pure DHA in the emulsion is 16%.

[0091] Comparative Example 3 1. Weigh 40 g of DHA algae oil B, 5 g of medium-chain triglycerides, 0.02 g of ascorbyl palmitate, and 0.2 g of sorbitan monolaurate. Incubate at 35°C, 7000 rpm, and shear for 5 min to obtain the oil phase.

[0092] 2. Weigh 2g of sodium ascorbate, 2g of polyoxyethylene (20) sorbitan monooleate, 7g of glycerol, 3g of lactose, and 40.78g of deionized water. Incubate at 35°C, 7000rpm, and shear for 5min to obtain the aqueous phase.

[0093] 3. Under continuous shearing condition, slowly add the oil phase into the water phase. After the oil and water phases are mixed, shear for 20 min at 35°C and 7000 rpm, and then homogenize at 60 MPa for 3 times to obtain DHA emulsion, which is sterilized and stored.

[0094] 4. Feature 1. The oil content of the emulsion is 45%, Feature 2. The content of oleic acid in the total oil is 1.8%, Feature 3. The content of pure DHA in the emulsion is 16%.

[0095] Comparative Example 4 1. Weigh 40g of DHA algae oil B, 8g of medium-chain triglycerides, 0.01g of propyl gallate, and 0.3g of propylene glycol fatty acid ester. Incubate at 40°C, 5000rpm, and shear for 5min to obtain the oil phase.

[0096] 2. Weigh 1 g of ascorbic acid, 1 g of sodium ascorbate, 1.5 g of sucrose fatty acid ester, 1.5 g of polyglycerol fatty acid ester, 5 g of glycerol, 4 g of maltodextrin, and 37.69 g of deionized water. Incubate at 40°C, 5000 rpm, and shear for 5 min to obtain the aqueous phase.

[0097] 3. Under continuous shearing condition, slowly add the oil phase into the water phase. After the oil and water phases are mixed, shear for 10 min at 40°C and 5000 rpm, and then homogenize twice at 70 MPa to obtain DHA emulsion, which is sterilized and stored.

[0098] 4. Feature 1. The oil content of the emulsion is 48%, Feature 2. The content of oleic acid in the total oil is 1.7%, Feature 3. The content of pure DHA in the emulsion is 16%.

[0099] Comparative Example 5 1. Weigh 50 g of DHA algae oil B, 0.02 g of TBHQ, 0.2 g of sorbitan monolaurate, and 0.2 g of propylene glycol fatty acid ester. Incubate at 40°C, 5000 rpm, and shear for 3 min to obtain the oil phase.

[0100] 2. Weigh 1 g of D-isoascorbic acid, 1 g of sodium D-isoascorbate, 1 g of polyglycerol fatty acid ester, 1 g of polyoxyethylene (20) sorbitan monolaurate, 3 g of glycerol, 3 g of trehalose, 3 g of lactose, and 36.58 g of deionized water. Incubate at 40°C, 5000 rpm, and shear for 3 min to obtain the aqueous phase.

[0101] 3. Under continuous shearing conditions, slowly add the oil phase into the water phase, shear for 15 min at 40°C and 5000 rpm, then homogenize twice at 80 MPa to obtain a DHA emulsion, which is sterilized and stored.

[0102] 4. Feature 1. The oil content of the emulsion is 50%, Feature 2. The content of oleic acid in the total oil is 2%, Feature 3. The content of pure DHA in the emulsion is 20%.

[0103] Comparative Example 6 1. Weigh 60g of DHA algae oil B, 0.04g of theaflavins, and 0.3g of polyglycerol ricinoleate. Incubate at 30°C, 7000rpm, and shear for 5min to obtain the oil phase.

[0104] 2. Weigh 0.5 g of D-isoascorbic acid, 1.5 g of polyglycerol fatty acid ester, 1.5 g of polyoxyethylene (20) sorbitan monolaurate, 1 g of glycerol, 3 g of trehalose, and 32.16 g of deionized water. Incubate at 30°C, 7000 rpm, and shear for 5 min to obtain the aqueous phase.

[0105] 3. Under continuous shearing condition, slowly add the oil phase into the water phase. After the oil and water phases are mixed, shear for 15 min at 30°C and 7000 rpm, and then homogenize twice at 60 MPa to obtain DHA emulsion, which is sterilized and stored.

[0106] 4. Feature 1. The oil content of the emulsion is 60%, Feature 2. The content of oleic acid in the total oil is 2%, Feature 3. The content of pure DHA in the emulsion is 24%.

[0107] Experimental Example 1 The present invention evaluates the stability of the DHA emulsions prepared in Examples 1-13 and Comparative Examples 1-6 (the components of Examples 1-13 and Comparative Examples 1-6 are as follows Figure 1 The following process is included: 1. Evaluation method: Centrifugal stability: 10000rpm, centrifugation for 30min.

[0108] 45℃7d stability: Stand at 45℃ for 7 days.

[0109] 4℃ 6 months stability: stand at 4℃ for 6 months.

[0110] Stability of pure milk at 37°C for 45 days: Add DHA emulsion to pure milk at a ratio of 200 mg / 100 g of DHA content in pure milk. After shearing, homogenization, sterilization and aseptic filling, let it stand at 37°C for 45 days. After the above treatment, evaluate the appearance and stability.

[0111] 2. Experimental results The results are shown in the following table: Table 1 Stability evaluation results of Examples 1-6 and Comparative Examples 1-6

[0112] As shown in the table above: The intensity of fishy smell is scored on a 7-point scale: none - 0, somewhat present - 1, slight - 2, moderate - 3~4, heavy - 5~6, very heavy - 7.

[0113] From the above stability evaluation results, we can know that: (1) Emulsion and its application stability: DHA algae oil A (derived from the fermentation of Schizochytrium CABIO-A-2-VI, DHA content ≥ 40%, oleic acid content ≥ 12%) was significantly better than DHA algae oil B (DHA content ≥ 40%, oleic acid content ≤ 2%). (2) Emulsion and its application stability: oil loading 40% = oil loading 50% > oil loading 60%.

[0114] (3) When DHA algae oil B (DHA content ≥ 40%, oleic acid content ≤ 2%) is selected and the addition amount is 40%, as the addition amount of high oleic sunflower oil increases, the oil loading of the emulsion increases, the content of oleic acid in the total oil increases, and the emulsion and its application stability first increase and then decrease. When the addition amount of high oleic sunflower oil is 5-12% (the pure DHA content in the emulsion is 16%, the oil loading is 45-52%, and the content of oleic acid in the total oil is 10.1%-18.9%), the appearance stability and sensory stability (smell) of the emulsion are optimal. The oleic acid content of Example 2 is relatively low (5.5%), and the oil loading of Example 6 is relatively high (56%), and the smell quality is reduced.

[0115] (4) When DHA algae oil B (DHA content ≥ 40%, oleic acid content ≤ 2%) was selected, adding high oleic sunflower oil could improve the stability of the emulsion and its application, while adding medium-chain triglycerides had no effect on the stability of the emulsion and its application.

[0116] Table 2 Stability evaluation results of Examples 7-13 and Comparative Example 5

[0117] As shown in the table above: The intensity of fishy smell is scored on a 7-point scale: none - 0, somewhat present - 1, slight - 2, moderate - 3~4, heavy - 5~6, very heavy - 7.

[0118] From the above results, we can know that: (1) Emulsion and its application stability: DHA algae oil A (derived from the fermentation of Schizochytrium CABIO-A-2-VI, DHA content ≥40%, oleic acid content ≥12%) was significantly better than DHA algae oil B (DHA content ≥40%, oleic acid content ≤2%). (2) When the DHA emulsion oil loading rate is 50%, as the oleic acid content in the oil phase increases, the emulsion and its application stability increase; when the emulsion oil loading rate is 50% and the oleic acid content in the total oil is ≥9.3%, the emulsion has the best appearance stability and sensory stability (smell). The oleic acid content of Example 8 is relatively low (4.9%), and the odor quality is reduced.

[0119] (3) Although Example 13 is superior in appearance stability and sensory stability (smell), the DHA content therein is only 4%, which does not meet the requirement of the present invention for "high DHA content".

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A DHA emulsion, characterized in that include: DHA algae oil and water; In terms of mass percentage, the DHA content in the DHA emulsion is 4-40%, the oil content of the DHA emulsion is 20-56%, and the oleic acid in the DNA emulsion accounts for 4-61% of the total oil content.

2. The DHA emulsion according to claim 1, characterized in that In terms of mass percentage, the DHA content in the DHA emulsion is 8-40%, the oil-carrying amount of the DHA emulsion is 40-52%, and the content of oleic acid in the DHA emulsion accounts for 9-46% of the total oil.

3. The DHA emulsion according to claim 1 or 2, characterized in that Also includes: One or more of an emulsifier, an antioxidant, an emulsifier aid or a flavoring agent.

4. The DHA emulsion according to claim 3, characterized in that The emulsifier includes an oil phase emulsifier and a water phase emulsifier; The oil phase emulsifier includes: one or more of mono- and di-glycerides, sucrose fatty acid esters, citric acid glycerol fatty acid esters, sorbitan monolaurate, sorbitan monopalmitate, sorbitan tristearate, sorbitan monooleate, propylene glycol fatty acid esters, succinic acid monoglyceride, polyglycerol ricinoleate or lactic acid fatty acid glyceride; The aqueous phase emulsifier includes: one or more of sucrose fatty acid ester, polyglycerol fatty acid ester, modified soybean lecithin, sodium octenyl succinate starch, polyoxyethylene (20) sorbitan monolaurate, polyoxyethylene (20) sorbitan monostearate, polyoxyethylene (20) sorbitan monooleate or polyoxyethylene (20) sorbitan monopalmitate.

5. The DHA emulsion according to claim 3, characterized in that The antioxidants include: oil phase antioxidants and water phase antioxidants; The oil phase antioxidant comprises: one or more of rosemary extract, vitamin E, theaflavin, BHA, BHT, ascorbyl palmitate, propyl gallate or TBHQ; The water phase antioxidant includes: one or more of D-isoascorbic acid, sodium D-isoascorbate, ascorbic acid or sodium ascorbate.

6. The DHA emulsion according to claim 3, characterized in that The auxiliary emulsifier is glycerol, and the flavoring agent is one or more of trehalose, lactose or maltodextrin.

7. The method for preparing the DHA emulsion according to any one of claims 1 to 6, characterized in that: include: DHA algae oil, oil phase antioxidant, and oil phase emulsifier are mixed according to a predetermined ratio, and fully sheared to obtain an oil phase; Mixing an aqueous phase antioxidant, an aqueous phase emulsifier, an auxiliary emulsifier, a flavoring agent, and water in a predetermined ratio to obtain an aqueous phase; Mixing the oil phase and the water phase under continuous shearing to obtain a primary emulsion; The primary emulsion is homogenized under high pressure to obtain a DHA emulsion.

8. A method for improving the stability of a DHA emulsion, characterized in that: include: The DHA emulsion is prepared by using DHA algae oil with high oleic acid content, or, The oleic acid content in the DHA emulsion is increased.

9. The method according to claim 8, characterized in that The DHA algae oil is derived from Schizochytrium CABIO-A-2-VI, and the deposit number of Schizochytrium CABIO-A-2-VI is CCTCC NO: M 2024961; and / or, increasing the oleic acid content in the DHA emulsion comprises increasing the oleic acid content to more than 9% of the total oil in the DHA emulsion.

10. Use of the DHA emulsion according to any one of claims 1 to 6 in the preparation of a liquid DHA product; the product comprising: One or more of nutritional supplements, functional beverages, dairy products or condiments.

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