Preparation method of protein-containing emulsion with low unpleasant odor
By using aqueous phase buffer with pH 6~7 in the emulsion, cross-linking reaction with protein, glutamine transaminase and ascorbyl palmitate, stable disulfide bonds are generated, which solves the problem of sulfide odor in the emulsion and improves the stability and flavor of the emulsion.
Patent Information
- Application Number
- CN202510942736.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-09
- Publication Date
- 2025-08-12
AI Technical Summary
The prior art cannot effectively reduce the odor of irritating sulfides generated by the redox reaction of sulfur-containing amino acids in emulsion products, resulting in the product producing adverse flavor and affecting the patient's acceptance.
Using aqueous phase buffer with pH 6~7, protein, glutamine transaminase and ascorbyl palmitate were added to generate highly stable disulfide bonds through cross-linking reactions, controlling the redox reaction of sulfur-containing amino acids, and adding ascorbyl palmitate inhibits the formation of other sulfides.
During the heat treatment process, the sulfide generation in the emulsion is significantly reduced, the stability and acceptance of the product are improved, and the adverse flavor is not produced during the shelf life.
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Figure CN120458270A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of food, in particular to a method for preparing a protein-containing emulsion with low bad smell. Background Art
[0002] The following statements merely provide background information related to the present disclosure and do not necessarily constitute prior art.
[0003] Foods for Special Medical Purposes (FSMPs) are medical foods designed to meet the nutritional needs of patients with restricted food intake, digestive and absorption disorders, or metabolic disorders. Emulsions are a key dosage form of FSMPs, offering high energy density, good stability, and easy absorption. They are widely used in areas such as postoperative nutritional support, cancer patients, and enteral nutrition. However, emulsions must undergo heat treatment for sterilization. During this process, sulfur-containing amino acids, emulsifiers, and other ingredients in the product system undergo redox reactions, generating sulfides with a pungent odor, which can lead to an unpleasant flavor. This unpleasant flavor can cause patients (especially those with sensitive tastes) to refuse to take the product, or, in more severe cases, induce nausea and vomiting, creating a psychological aversion.
[0004] Existing methods for combating unpleasant odors in food include: using adsorptive materials to absorb unpleasant odor molecules in food; masking unpleasant odors by adding aromatic substances; destroying the activity of odor-producing enzymes in food through heat treatment; and using microencapsulation technology to encapsulate unpleasant odorous substances in food, encapsulating them in tiny capsules and masking the odor. However, none of these existing methods address the pungent odor caused by sulfides produced by redox reactions of sulfur-containing amino acids and other ingredients in food.
[0005] In view of this, the present invention is proposed. Summary of the Invention
[0006] The object of the present invention is to provide a method for preparing a protein-containing emulsion with low bad smell, so as to reduce the pungent smell produced by sulfur-containing amino acids in the protein.
[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions: In a first aspect, a method for preparing a protein-containing emulsion with low bad odor is provided, the preparation method comprising: A. Provide an aqueous buffer solution with a pH of 6 to 7; B. dispersing the protein, transglutaminase and ascorbyl palmitate in the aqueous buffer solution, and reacting the mixture under stirring to obtain a protein dispersion; The feed ratio of protein to the aqueous buffer is 50-200 g / L, the feed ratio of transglutaminase to the aqueous buffer is 0.05-0.5 g / L, and the feed ratio of ascorbyl palmitate to the aqueous buffer is 0.01-0.05 g / L; C. adding the remaining components to the protein dispersion, inactivating transglutaminase after dispersion, and obtaining the low-bad-smell protein-containing emulsion.
[0008] In an optional embodiment, in step B, the reaction time is 60-180 min, and the reaction temperature is 40-50°C.
[0009] In an optional embodiment, the buffer system of the aqueous buffer solution is a lactic acid-sodium lactate buffer system, and the total concentration of lactic acid and sodium lactate is 0.01 to 0.1 mol / L.
[0010] In an optional embodiment, the remaining components include one or more of emulsifiers, sugars, fats, vitamins and minerals.
[0011] In an optional embodiment, the low-bad-smell protein-containing emulsion is a complete nutritional formula food for special medical purposes, and the remaining components include emulsifiers, sugars, fats, vitamins and minerals.
[0012] In an optional embodiment, the step C further comprises performing at least one of homogenizing, encapsulating and sterilizing the dispersed mixture.
[0013] In an optional embodiment, the inactivation of transglutaminase in step C is achieved by a sterilization step.
[0014] In an optional embodiment, the preparation method comprises the following steps: A. Heat purified water in a water bath and adjust the pH to 6-7 to obtain aqueous buffer solution. B. Dispersing the protein, transglutaminase, and ascorbyl palmitate in the aqueous buffer solution simultaneously under stirring, and maintaining stirring to obtain a protein dispersion; C. Adding polysaccharide, fat, emulsifier, vitamins and minerals to the protein dispersion, and dispersing, homogenizing, encapsulating and sterilizing in sequence to obtain the low-odor protein-containing emulsion.
[0015] In a second aspect, a protein-containing emulsion with low bad smell prepared by the preparation method described in the first aspect is provided.
[0016] In an optional embodiment, the low-bad-smell protein-containing emulsion is a complete nutritional formula food for special medical purposes.
[0017] Compared with the prior art, the present invention has the following beneficial effects: The preparation method of the low-bad-smell protein-containing emulsion provided by the present invention is based on the traditional process. After the protein is specially treated, the cross-linking of the sulfur-containing amino groups inside the protein is catalyzed by glutamine transaminase. The reaction progress is controlled by controlling the amount of the added enzyme, the reaction pH value and other reaction conditions to generate disulfide bonds with high thermal stability, thereby reducing the generation of sulfur-containing compounds with peculiar smell in the protein in the protein-containing emulsion during the heat treatment process of the processing technology; at the same time, ascorbyl palmitate is added. The above-mentioned substance has a higher priority in the redox reaction than sulfur-containing amino acid residues during the heat treatment of the dairy product, which can further reduce the formation of bad flavor of the product. The preparation method of the present invention is more stable under the thermal process, which improves the acceptance of the protein-containing emulsion by the user population.
[0018] The protein-containing emulsion prepared by the method has good properties and stability, reduced sulfide content, and unpleasant flavor substances close to the threshold. In the preferred embodiment, no unpleasant flavor will be produced within a certain period of time. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific 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.
[0020] Figure 1 The particle size distribution curves of Examples 1 to 4 and Comparative Examples 1, 2, and 6 are shown. DETAILED DESCRIPTION
[0021] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0022] It should be noted that: In this document, unless otherwise specified, all implementation methods and preferred implementation methods mentioned herein can be combined with each other to form a new technical solution; all technical features and preferred features mentioned herein can be combined with each other to form a new technical solution; the components involved or their preferred components can be combined with each other to form a new technical solution.
[0023] Herein, unless otherwise stated, various reactions or operation steps may or may not be performed in sequence.
[0024] In this document, unless otherwise specified, arbitrary numbering is used to distinguish one entity or behavior from another entity or behavior, and does not necessarily require or imply any actual relationship, order, or importance between these entities or behaviors, such as numbering first, second; A, B, C... etc. It should be noted that uppercase and lowercase letters of the same letter have different meanings.
[0025] As used herein, "and / or" is used to indicate that one or both of the stated situations may occur, for example, A and / or B includes (A and B) and (A or B).
[0026] As used herein, unless otherwise stated, "optionally," "optional," "optional," or "optional" means that the subsequently described event or circumstance may but need not occur, and that the description includes instances where the event or circumstance occurs and instances where it does not.
[0027] Herein, the terms "comprise" or "comprising" are intended to imply the inclusion of stated elements, integers or steps, but not the exclusion of any other elements, integers or steps.
[0028] Unless otherwise indicated, the professional and scientific terms used herein are the same as those familiar to those skilled in the art. In addition, any method or material similar or equivalent to the described content can also be applied to the present invention.
[0029] In a first aspect, a method for preparing a protein-containing emulsion with low bad odor is provided, the preparation method comprising: A. Provide an aqueous buffer solution with a pH of 6 to 7.
[0030] B. Dispersing protein, transglutaminase, and ascorbyl palmitate in the aqueous buffer solution and reacting under stirring to obtain a protein dispersion. After the above reaction, the protein and amino acid molecules undergo cross-linking under the action of the enzyme, and the sulfur-containing amino acid residues are encapsulated within the molecules. During the heat treatment of the dairy product, compared with conventional processes, the number of reaction substrates for molecules that produce off-flavors can be reduced, thereby reducing the unpleasant flavor of the finished product. Simultaneously, the addition of ascorbyl palmitate, which has a higher redox reaction priority than sulfur-containing amino acid residues during the heat treatment of the dairy product, can further reduce the formation of unpleasant flavors in the product. Furthermore, the addition of ascorbyl palmitate during the protein processing stage can inhibit the oxidation of other sulfur-containing nutrients (such as thiamine, i.e., vitamin B1) to form sulfides due to factors such as light and temperature during the product's shelf life.
[0031] The feed ratio of protein to the aqueous buffer is 50-200 g / L, for example, but not limited to, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190 or 200 g / L.
[0032] The feed ratio of transglutaminase to the aqueous buffer is 0.05-0.5 g / L, for example, but not limited to, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45 or 0.5 g / L.
[0033] The feed ratio of ascorbyl palmitate to the aqueous buffer solution is 0.01 to 0.05 g / L, for example, but not limited to, 0.01, 0.02, 0.03, 0.04 or 0.05 g / L, preferably 0.02 to 0.05 g / L.
[0034] The above feed ratio refers to the mass volume ratio of protein, transglutaminase or ascorbyl palmitate and the aqueous buffer obtained in step A before any component of step B is added.
[0035] C. adding the remaining components to the protein dispersion, inactivating transglutaminase after dispersion, and obtaining the low-bad-smell protein-containing emulsion.
[0036] The above preparation method uses the specific catalysis of sulfur-containing amino acids by transglutaminase to cross-link the exposed sulfur-containing amino acid residues in the system, forming highly stable disulfide bonds, thereby improving the stability of the emulsion system under thermal process conditions and reducing the formation of sulfur-containing compounds with unpleasant flavors. At the same time, in order to maintain the enzyme activity in the reaction system at a high level, the reaction system needs to be adjusted to a pH of 6-7 using a buffer salt. In an optional embodiment, in step A, the buffer system of the aqueous phase buffer is a lactic acid-sodium lactate buffer system, and the total concentration of lactic acid mixed with sodium lactate is 0.01-0.1 mol / L, for example, but not limited to 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09 or 0.1 mol / L. Using a lactic acid-sodium lactate buffer system as a buffer salt for adjusting the pH in the reaction system can reduce the formation of unpleasant flavor substances compared to other pH adjusters. In particular, after using the lactic acid-sodium lactate buffer system to adjust the pH in the system, the final product of the special medical purpose complete nutritional emulsion has a lower sulfide content and a lower bad flavor score than the finished products of the special medical purpose complete nutritional emulsion prepared with other pH regulators.
[0037] In an optional embodiment, the step A further comprises heating the aqueous buffer solution to the reaction temperature required for the step B.
[0038] In an optional embodiment, in step B, the reaction time is 60-180 min, for example, but not limited to, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170 or 180 min; the reaction temperature is 40-50°C, for example, but not limited to, 40, 42, 45, 48 or 50°C.
[0039] In an optional embodiment, the protein includes one or more of casein, whey protein, hydrolyzed whey protein and soy protein.
[0040] In an optional embodiment, the remaining components include one or more of emulsifiers, sugars, fats, vitamins and minerals.
[0041] In an optional embodiment, the emulsifier includes but is not limited to one or more of soybean lecithin, mono- and diglycerol fatty acid esters, citric acid fatty acid esters, sucrose esters, and sorbic acid esters.
[0042] In an optional embodiment, the sugar comprises a polysaccharide. Optionally, the polysaccharide includes but is not limited to one or more of maltodextrin, resistant dextrin, oligofructose, inulin, soybean polysaccharide and tapioca dextrin.
[0043] In an optional embodiment, the fat includes but is not limited to one or more of soybean oil, rapeseed oil, olive oil, linseed oil, fish oil, safflower oil, corn oil, and medium-chain triglycerides.
[0044] In an optional embodiment, the vitamins include one or more of vitamin A, vitamin D, vitamin E, vitamin K1, vitamin B1, vitamin B2, vitamin B6, vitamin B12, niacin, folic acid, pantothenic acid, vitamin C and biotin.
[0045] In alternative embodiments, the minerals include one or more of sodium, potassium, copper, magnesium, iron, zinc, manganese, calcium, phosphorus, iodine, chloride, and selenium.
[0046] In an optional embodiment, the step C further comprises subjecting the dispersed mixture to at least one of homogenization, encapsulation and sterilization.
[0047] In an optional embodiment, the inactivation of transglutaminase in step C is achieved by a sterilization step.
[0048] In an optional embodiment, the sterilization conditions include sterilization at 121°C for 15 minutes. The temperature can be raised to 121°C in the last step of the emulsion production process, thereby achieving the dual purposes of emulsion sterilization and enzyme inactivation, thereby achieving the effect of reducing the unpleasant flavor of the emulsion without destroying the emulsion system environment.
[0049] In an optional embodiment, the step C includes dispersing each component into the protein dispersion and then homogenizing it.
[0050] In an optional embodiment, the homogenization condition includes homogenizing twice under 500 Bar conditions.
[0051] In an optional embodiment, the low-bad-smell protein-containing emulsion is a complete nutritional formula food for special medical purposes, and the remaining components include emulsifiers, sugars, fats, vitamins and minerals.
[0052] In an optional embodiment, the low-unpleasant-smell protein-containing emulsion is a nutritionally complete formula food for special medical purposes, and the preparation method comprises the following steps: A. Heat purified water in a water bath and adjust the pH to 6-7 to obtain aqueous buffer solution. B. Dispersing the protein, transglutaminase, and ascorbyl palmitate in the aqueous buffer solution simultaneously under stirring, and maintaining stirring to obtain a protein dispersion; C. Adding polysaccharide, fat, emulsifier, vitamins and minerals to the protein dispersion, and dispersing, homogenizing, encapsulating and sterilizing in sequence to obtain the low-odor protein-containing emulsion.
[0053] In a second aspect, a protein-containing emulsion with low bad smell prepared by the preparation method described in the first aspect is provided.
[0054] In an optional embodiment, the low-bad-smell protein-containing emulsion is a complete nutritional formula food for special medical purposes.
[0055] The present invention is further described below by way of specific examples. However, it should be understood that these examples are merely provided for more detailed description and are not to be construed as limiting the present invention in any form.
[0056] Examples 1 to 7 Examples 1 to 7 provide a method for preparing a nutritionally complete formula food for special medical purposes, comprising the following steps: A. Heat purified water in a water bath and adjust the pH using a pH adjuster to obtain an aqueous buffer solution. B. Start stirring and simultaneously disperse the protein, transglutaminase, and ascorbyl palmitate in the aqueous buffer solution while maintaining stirring to obtain a protein dispersion; C. Add 100 g / L maltodextrin, 50 g / L resistant dextrin, 13 g / L medium chain triglycerides, 12 g / L soybean oil, 5 g / L olive oil, 2 g / L soybean lecithin, 260 mg / L vitamin C, 15 mg / L vitamin E, 10 mg / L niacin, 7 mg / L pantothenic acid, 2.4 mg / L vitamin B2, 2.0 mg / L vitamin B1, 1.8 mg / L vitamin B6, 0.6 mg / L vitamin A, 0.4 mg / L folic acid, and 1.5 mg / L vitamin K1 to the reaction solution. The mixture was added with 1% paraben, 0.06 mg / L calcium carbonate, 0.045 mg / L biotin, 0.012 mg / L vitamin D3, 0.003 mg / L vitamin B12, 1600 mg / L potassium chloride, 1500 mg / L sodium chloride, 1100 mg / L sodium citrate, 720 mg / L tricalcium phosphate, 560 mg / L tricalcium phosphate, 240 mg / L magnesium sulfate, 18 mg / L ferrous sulfate, 9 mg / L zinc sulfate, 3 mg / L manganese sulfate, 1 mg / L copper sulfate, 0.12 mg / L potassium iodide and 0.06 mg / L sodium selenite, and the mixture was evenly dispersed, homogenized twice at 500 bar, sealed with nitrogen and sterilized at 121°C for 15 minutes to obtain a finished product of a complete nutritional formula food for special medical purposes.
[0057] The pH adjuster in Examples 1-4 and Examples 6-7 is a lactic acid-sodium lactate buffer system, and the amount added is adjusted according to the pH of each example in Table 1.
[0058] The pH regulator in Example 5 is a citric acid-sodium citrate buffer system.
[0059] The amounts of ingredients and process parameters of Examples 1 to 7 are shown in Table 1.
[0060] Table 1 Ingredient dosage and process parameters of Examples 1 to 7
[0061] The feed ratio in the above table refers to the mass-to-volume ratio of protein, transglutaminase or ascorbyl palmitate and the aqueous buffer obtained in step A before any components of step B are added.
[0062] Comparative Example 1 Comparative Example 1 provides a method for preparing a nutritionally complete formula food for special medical purposes, comprising the following steps: Water, 150g of protein, polysaccharide, fat, emulsifier, vitamins, minerals and other substances are evenly dispersed, homogenized twice under 500Bar conditions, nitrogen-filled and sealed, and sterilized at 121°C for 15 minutes to obtain a finished product of a complete nutritional formula food for special medical purposes.
[0063] Comparative Examples 2 to 8 Comparative Examples 2 to 8 respectively provide a method for preparing a nutritionally complete formula food for special medical purposes, comprising the following steps: A. Heat purified water in a water bath and adjust the pH using a pH adjuster to obtain an aqueous buffer solution. B. Start stirring and simultaneously disperse the protein, transglutaminase, and ascorbyl palmitate in the aqueous buffer solution while maintaining stirring to obtain a protein dispersion; C. Adding polysaccharides, fats, emulsifiers, vitamins, minerals and other substances to the reaction solution, uniformly dispersing the mixture, homogenizing the mixture twice at 500 bar, nitrogen-filling and sealing the mixture, and sterilizing the mixture at 121° C. for 15 minutes to obtain a finished product of a nutritionally complete formula food for special medical purposes.
[0064] The pH adjuster in Comparative Examples 2 to 8 is a lactic acid-sodium lactate buffer system, and the amount added is adjusted according to the pH of each example in Table 2. The amount of ingredients and process step parameters of Comparative Examples 2 to 8 are shown in Table 2.
[0065] Table 2 Ingredient dosage and process parameters of Comparative Examples 2 to 8
[0066] The feed ratio in the above table refers to the mass-to-volume ratio of protein, transglutaminase or ascorbyl palmitate and the aqueous buffer obtained in step A before any components of step B are added.
[0067] Effect Example 1 The following physical, chemical and component analyses were performed on the complete nutritional formula foods for special medical purposes prepared in Examples 1 to 7 and Comparative Examples 1 to 8. The results are shown in Tables 3, 4 and Figure 1 As shown: Table 3 Flavor evaluation results
[0068] Table 4 Characteristic analysis results
[0069] ① Appearance: Appearance is the first perception of a product by consumers (patients), directly influencing acceptance and willingness to use. Patients often experience loss of appetite or difficulty swallowing due to illness. Uneven color, precipitation, or stratification (such as oil-water separation) can lead to psychological rejection and reduced compliance. The experimental results in Table 4 show that a uniform emulsion cannot be achieved when the protein content is too high (casein addition level is 250g / L).
[0070] ② Particle size (nm) and standard deviation (nm): The particle size of the emulsion can directly reflect the process of emulsion preparation and can affect the stability of the emulsion to a certain extent. At the same time, the particle size can directly affect the bioavailability and digestion kinetics of nutrients. Generally speaking, the particle size of nutritional preparations used in the intestine should not exceed 600nm. In addition, the standard deviation of the particle size reflects the uniformity of the particles in the emulsion. The smaller the standard deviation, the more uniform the emulsion particles are and the better the stability. From Table 4 and Figure 1 The experimental results show that the average particle size of the emulsions obtained by the preparation methods provided in the examples does not exceed 600 nm, indicating that the protein treatment method of the present invention has no adverse effect on the stability of the emulsion.
[0071] ③ Stability: 10 mL of the emulsion was placed in a centrifuge tube and centrifuged at 2000 r·min. -1 After centrifugation for 15 min, 50 μL of the emulsion was taken from the middle, added to a test tube containing 5 mL of 0.1% SDS, and shaken to mix. The absorbance was measured at 500 nm (A t Take 50 μL of the uncentrifuged emulsion sample and perform the same operation to measure the absorbance (A0). Calculate the stability coefficient K according to formula (1): E The smaller the stability coefficient, the better the stability. Generally, a stability coefficient of less than 10% indicates a relatively stable emulsion. A stability coefficient of 10-20% should be considered to set a reasonable shelf life to ensure the appearance of the product.
[0072] Formula (1).
[0073] As can be seen from the experimental results in Table 4, when the protein content is too high (casein addition is 250 g / L), a stable emulsion cannot be obtained, while the other preparation methods can all produce relatively stable emulsions. This shows that the protein treatment method of the present invention has no adverse effect on the stability of the emulsion.
[0074] ④Concentration of hydrogen sulfide in the product (μg / L) Hydrogen sulfide is formed by the Strecker degradation of cysteine and diketone compounds in proteins. It can also be produced by the degradation of methionine and methionine. The concentration of hydrogen sulfide in the product generally increases with increasing heat treatment intensity and is a major contributor to the cooking odor in protein-containing dairy products. The experimental results in Table 3 show that the emulsions obtained by the preparation methods provided in Examples 1 to 6 have relatively low hydrogen sulfide concentrations, with Examples 2 and 4 achieving the best results.
[0075] ⑤Methyl mercaptan concentration in the product (μg / L) Methionine and thiamine undergo Strecker degradation, with intermediate products including 3-methylthiopropionaldehyde, dimethyl sulfide, and dimethyl disulfide. Riboflavin (vitamin B12) catalyzes the decomposition of methionine into 3-methylthiopropionaldehyde, which, under the influence of light and other factors, continuously forms methyl mercaptan, sulfides, and disulfides. Methyl mercaptan is the primary cause of the product's cooking odor. The experimental results in Table 3 show that the emulsions prepared using the preparation methods provided in Examples 1 to 8 have relatively low methyl mercaptan concentrations, with Examples 2 and 4 achieving the best results.
[0076] ⑥Total sulfide concentration in the product (μg / L) In addition to hydrogen sulfide and methyl mercaptan, other sulfides such as dimethyl sulfide, dimethyl disulfide, dimethyl sulfone, dimethyl sulfide, dimethyl trisulfide, carbonyl sulfide, and carbon disulfide all have a certain impact on the flavor of dairy products. However, due to the relatively low content of these substances, they are expressed as sulfides. As can be seen from the experimental results in Table 3, the total sulfide concentration in the emulsions obtained by the preparation methods provided in Examples 1 to 7 is relatively low, with Examples 2 and 4 achieving the best results.
[0077] ⑦Sensory analysis The most prominent unpleasant flavor of the special medical complete nutrition product is a cooking taste, primarily derived from the two compounds mentioned above. A panel of 10 trained sensory analysts evaluated the flavor of the complete nutrition emulsion on a scale of 0 to 5, with 0 indicating no unpleasant flavor and 5 indicating a strong unpleasant flavor. The prepared complete nutrition emulsion and the emulsion were accelerated for three months at a temperature of 30°C ± 2°C and a humidity of 60% ± 5%. By combining the detection of the three flavor compounds in the examples and comparative examples with sensory analysis, an evaluation scale for product unpleasant flavors was established.
[0078] As can be seen from the experimental results in Table 3, the emulsions obtained by the preparation methods provided in Examples 1-8 achieved good unpleasant flavor scores. Furthermore, the emulsions obtained by the preparation methods provided in Examples 1-4 still achieved good unpleasant flavor scores after three months of accelerated treatment, indicating that the preparation methods provided in Examples 1-4 can maintain the emulsions free of unpleasant flavor substances for an extended period of time.
[0079] From the above results, it can be seen that the complete nutritional emulsions prepared using Examples 1 to 4 have low concentrations of the two sulfur-containing compounds, even close to the flavor thresholds of substances reported in the literature, and their unpleasant flavor scores are also at a very low level.
[0080] Although Example 5 and Comparative Example 8 had low concentrations of both sulfides upon production and achieved better unpleasant flavor scores than the other comparative examples, the unpleasant flavors increased after three months of accelerated storage at 30°C ± 2°C and 60% ± 5% humidity. This is because the thiamine (vitamin B1) and riboflavin (vitamin B2) contained in the complete nutritional emulsion react with protein during storage, oxidizing to hydrogen sulfide and methyl mercaptan, resulting in unpleasant flavors. Examples 1-4 utilize lactic acid, sodium lactate, and ascorbyl palmitate, which have antioxidant properties and can inhibit the oxidation of thiamine and riboflavin during shelf life, thereby reducing the formation of unpleasant flavor compounds during storage.
[0081] The particle size and stability of the special medical emulsions prepared in Examples 1 to 4 are consistent with those of the traditional process, and there is no negative impact due to the cross-linking of proteins by transglutaminase; however, in Comparative Example 6, a higher concentration of transglutaminase is used, and the protein cross-linking reaction exceeds the maximum limit of the emulsion system, the system steady state is destroyed, the emulsion particle size increases, and the stability deteriorates.
[0082] 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 above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method for preparing a protein-containing emulsion with low bad smell, characterized in that: include: A. Provide an aqueous buffer solution with a pH of 6 to 7; B. dispersing the protein, transglutaminase and ascorbyl palmitate in the aqueous buffer solution, and reacting the mixture under stirring to obtain a protein dispersion; The feed ratio of protein to the aqueous buffer is 50-200 g / L, the feed ratio of transglutaminase to the aqueous buffer is 0.05-0.5 g / L, and the feed ratio of ascorbyl palmitate to the aqueous buffer is 0.01-0.05 g / L; C. adding the remaining components to the protein dispersion, inactivating transglutaminase after dispersion, and obtaining the low-bad-smell protein-containing emulsion.
2. The preparation method according to claim 1, characterized in that In step B, the reaction time is 60-180 min, and the reaction temperature is 40-50° C.
3. The preparation method according to claim 1, characterized in that The buffer system of the aqueous phase buffer solution is a lactic acid-sodium lactate buffer system, and the total concentration of lactic acid and sodium lactate is 0.01-0.1 mol / L.
4. The preparation method according to claim 1, characterized in that The remaining components include one or more of emulsifiers, sugars, fats, vitamins and minerals.
5. The preparation method according to claim 4, characterized in that The low-bad-smell protein-containing emulsion is a complete nutritional formula food for special medical purposes, and the remaining components include emulsifiers, sugar, fat, vitamins and minerals.
6. The preparation method according to claim 1, characterized in that The step C further comprises performing at least one of homogenizing, encapsulating and sterilizing the dispersed mixture.
7. The preparation method according to claim 6, characterized in that In the step C, the inactivation of transglutaminase is achieved by a sterilization step.
8. The preparation method according to any one of claims 1 to 7, characterized in that The steps include: A. Heat purified water in a water bath and adjust the pH to 6-7 to obtain aqueous buffer solution. B. Dispersing the protein, transglutaminase, and ascorbyl palmitate in the aqueous buffer solution simultaneously under stirring, and maintaining stirring to obtain a protein dispersion; C. Adding polysaccharide, fat, emulsifier, vitamins and minerals to the protein dispersion, and dispersing, homogenizing, encapsulating and sterilizing in sequence to obtain the low-odor protein-containing emulsion.
9. The protein-containing emulsion with low bad smell prepared by the preparation method according to any one of claims 1 to 8.
10. The low-bad-smell protein-containing emulsion according to claim 9, characterized in that The low-bad-smell protein-containing emulsion is a complete nutritional formula food for special medical purposes.