A myofibrillar protein-modified gum arabic composite emulsion and its application

Abstract

The present invention belongs to the technical field of processing and producing Western-style emulsified sausages, and specifically relates to a myofibrillar protein-modified gum arabic composite emulsion and its application. The present invention replaces the animal fat in the formula of traditional Western-style emulsified sausages with a myofibrillar protein-modified gum arabic composite pre-emulsion. The resulting improved Western-style emulsified sausage not only reduces the product's saturated fatty acids but also prolongs the product's oxidative stability during storage. Furthermore, the improved Western-style emulsified sausage with the addition of the myofibrillar protein-modified gum arabic composite pre-emulsion has a richer nutritional value, retains more flavor substances in the product, and can gain higher consumer favorability.

Description

Technical Field

[0001] The invention belongs to the technical field of processing and producing western-style emulsified sausages, and particularly relates to a myofibrillar protein-modified gum arabic composite emulsion and application thereof. Background Art

[0002] Traditional low-temperature emulsified meat products are high in animal fat. Numerous studies have shown that long-term consumption of saturated fatty acids and cholesterol is detrimental to human health. The Healthy China Action Plan (2019-2030), developed by the National Health Commission by the end of June 2019, explicitly calls for a balanced diet and cardiovascular disease prevention and treatment plan. Therefore, the development of low-fat emulsified meat products by replacing animal fat with vegetable oils can reduce saturated fatty acid and cholesterol content while maintaining product quality.

[0003] However, vegetable oils are high in unsaturated fatty acids, which can easily lead to oxidative rancidity during processing and storage. Oxidative rancidity in emulsion-based meat emulsions can directly impact product quality, severely impacting shelf life and consumer adoption. Therefore, a processing method that can address this oxidative risk while ensuring product quality is urgently needed. Summary of the Invention

[0004] To address the oxidative rancidity problem induced by replacing animal fat with vegetable oil in low-fat Western-style emulsified sausages, the present invention adds a gallic acid-modified gum arabic-myofibrillar protein composite pre-emulsion to the product formula to replace animal fat to prepare an improved Western-style emulsified sausage. After the animal fat in the product is replaced by the composite pre-emulsion, the saturated fatty acid content is significantly reduced, meeting the needs of modern consumers for a low-fat, healthy diet. Furthermore, the modified gum arabic in the composite pre-emulsion can effectively inhibit the formation of oil oxidation products, maintain the product's oxidative stability during storage, extend the product's shelf life, and reduce the economic losses to companies caused by rapid product deterioration.

[0005] To achieve the above objectives, the present invention provides the following technical solutions:

[0006] A myofibrillar protein-modified gum arabic composite emulsion comprises myofibrillar protein and modified gum arabic; the myofibrillar protein is prepared in a myofibrillar protein solution with a mass percentage of 1.8-2.2%; the modified gum arabic is prepared in a phosphate buffer solution to form a modified gum arabic solution with a mass percentage of 1.1-1.3%; and the volume ratio of the myofibrillar protein solution to the modified gum arabic solution is 1:1±0.1.

[0007] The present invention also provides a method for preparing the above-mentioned myofibrillar protein-modified gum arabic composite emulsion, comprising mixing a myofibrillar protein solution having a mass percentage of 1.8-2.2% and a modified gum arabic solution having a mass percentage of 1.1-1.3% in a volume ratio of 1:1±0.1, adding vegetable oil, and homogenizing at a high speed of 8000-12000×g to obtain the myofibrillar protein-modified gum arabic composite emulsion.

[0008] Furthermore, the preparation method of the myofibrillar protein includes: cutting the longissimus dorsi muscle of the pig, removing the connective tissue, cutting the muscle into pieces along the texture and crushing the muscle, adding the muscle into a phosphate buffer solution and crushing the muscle at a uniform speed, centrifuging the obtained homogenate, pouring out the supernatant and taking the precipitate, adding NaCl solution to the precipitate, crushing the homogenate, filtering the homogenate to remove excess fiber tissue, centrifuging the filtrate and taking the precipitate to obtain the myofibrillar protein.

[0009] Furthermore, the preparation method of the modified gum arabic includes: dissolving gum arabic in phosphate buffer (a mixture of 160 mL of 0.2 mol / L NaH2PO4•2 H2O and 84 mL of 0.2 mol / L NaH2PO4•2 H2O, pH 7.5), sequentially adding a methanol solution containing phenolic acid and laccase to the solution, placing the mixed solution in a magnetic stirring reactor to react under atmospheric conditions, after the reaction is terminated, centrifuging the mixed solution, and removing ethanol and part of the water using a rotary evaporator, dialyzing the concentrated solution obtained by rotary evaporation, and then freeze-drying to obtain modified gum arabic.

[0010] Furthermore, the phenolic acid is gallic acid.

[0011] Furthermore, the mixed solution was placed in a magnetic stirring reactor and reacted for 4 h under atmospheric conditions, and an equal volume of ethanol was added to the solution to terminate the reaction.

[0012] Furthermore, ethanol and part of water were removed using a rotary evaporator at 40°C to 50°C.

[0013] Furthermore, in the preparation step of the myofibrillar protein, the phosphate buffer comprises: 10 mM Na2HPO4•12 H2O, 0.1 M NaCl, 2 mM MgCl2•6 H2O and 1 mM EGTA, with a pH of 7.0, and the myofibrillar protein diluent comprises: 15 mmol / L PIPES and 0.6 mol / L NaCl, with a pH of 6.25.

[0014] The present invention also provides the use of the myofibrillar protein-modified gum arabic composite emulsion in the preparation of Western-style emulsified sausage.

[0015] Furthermore, the above-mentioned myofibrillar protein-modified gum arabic composite emulsion is added at a mass ratio of 18-22% of the total meat.

[0016] The present invention also provides a process for producing an improved Western-style emulsified sausage with high antioxidant activity, which mainly includes the following technical steps:

[0017] (1) Raw material preparation and processing: Select fresh longissimus dorsi muscle of pig, remove fat and connective tissue, mince with a meat grinder at 4℃, and set aside for use.

[0018] (2) Preparation of myofibrillar protein-modified gum arabic composite pre-emulsion: Myofibrillar protein was dissolved in protein buffer (15 mmol / L PIPES mixed with 0.6 mol / L NaCl, pH 6.25) at a mass ratio of 2% to prepare a myofibrillar protein solution; modified gum arabic was dissolved in phosphate buffer (160 mL NaH2PO4•2 H2O (0.2 mol / L) mixed with 84 mL NaH2PO4•2 H2O (0.2 mol / L), pH 7.5) at a mass ratio of 1.2% to obtain a modified gum arabic solution; the primary myofibrillar protein solution and the modified gum arabic solution were stirred and hydrated in a ratio of 1:1 to prepare a composite solution of 1% myofibrillar protein + 0.6% modified gum arabic. Vegetable oil was added to each composite solution at a ratio of 20% (w / w). The mixture was homogenized at 10,000 × g for 1 min to obtain a myofibrillar protein-modified gum arabic composite emulsion. All of the above operations were performed at 4°C. Since the present invention aims to address the high saturated fatty acid content of traditional Western-style emulsified sausages, the vegetable oil used is one rich in unsaturated fatty acids, such as soybean oil or sunflower oil.

[0019] (3) Adding ingredients: Weigh the ingredients according to the mass percentage of the total meat, including salt 1-3%, sugar 5-7%, MSG 0.1-0.5%, white pepper 0.1-0.5%, light soy sauce 1-5%, cooking wine 1-3%, five-spice powder 0.1-0.5%, phosphate 0.1-0.5%, and some crushed ice.

[0020] (4) Meat emulsification: For traditional Western-style emulsified sausage, 20% ground pork back fat was added based on the total meat volume. For modified Western-style emulsified sausage, 20% myofibrillar protein-modified gum arabic composite pre-emulsion was added based on the total meat volume. The ground pork and myofibrillar protein-modified gum arabic composite pre-emulsion were placed in a chopper for meat emulsification.

[0021] (5) Filling and steaming: Use a sausage stuffer to fill the emulsified meat into the casing, tie the two ends of the casing tightly, and put it into boiling water for cooking.

[0022] (6) Vacuum packaging: After cooking, the emulsified sausage is cooled to room temperature and packaged using a vacuum packaging machine.

[0023] Furthermore, the preparation method of myofibrillar protein includes the following steps: first, thaw pre-cut longissimus dorsi muscle at 4°C, remove connective tissue, cut along the grain, and place in a tissue grinder. Add phosphate buffer (10 mM Na₂HPO₄·12 H₂O, 0.1 M NaCl, 2 mM MgCl₂·6 H₂O, 1 mM EGTA, pH 7.0) equivalent to four volumes of the meat sample to the grinder, and grind at a constant speed for 1 minute. The resulting homogenate is centrifuged, the supernatant is decanted, and the precipitate is collected. Four volumes of 0.1 M NaCl solution are then added to the precipitate, which is then homogenized and filtered to remove excess fibrous tissue. Following the above steps, centrifugation is performed to obtain the precipitate, which is myofibrillar protein.

[0024] Furthermore, the preparation method of modified gum arabic includes the following steps: first, 1 g of gum arabic is weighed and dissolved in 45 mL of phosphate buffer (a mixture of 160 mL of NaH2PO4•2H2O (0.2 mol / L) and 84 mL of NaH2PO4•2H2O (0.2 mol / L), pH 7.5). A methanol solution (5 mL) containing phenolic acids (50 mM) and laccase (15 LAMU / g) are then added to the solution. The mixed solution is placed in a magnetic stirring reactor (constant speed) and reacted under atmospheric conditions (without dissolved oxygen limitation) for 4 h. An equal volume of ethanol is then added to the solution to terminate the reaction. The mixed solution is centrifuged to remove water-insoluble substances. The ethanol and some water are then removed using a rotary evaporator at 40°C to 50°C. The concentrated solution obtained by rotary evaporation is dialyzed against ultrapure water using a biotechnology-grade dialysis membrane to remove excess salts. The purified solution is freeze-dried for 72 h, and the resulting modified gum arabic powder is sealed and stored dry until use.

[0025] Furthermore, laccase-mediated grafted phenolic acids are plant-derived phenolic substances with high levels of antioxidant activity. Beneficial effects

[0026] Compared with traditional Western-style emulsified sausages prepared with animal oil, adding myofibrillar protein emulsion, natural gum arabic composite pre-emulsion and modified gum arabic composite pre-emulsion to the formula reduced the product cooking loss by 28.75%, 40.37% and 43.43% respectively, which means that formula improvement can increase the product yield.

[0027] Compared with traditional Western-style emulsified sausages prepared with animal oil, the hardness of products prepared with myofibrillar protein emulsion, natural gum arabic composite pre-emulsion and modified gum arabic composite pre-emulsion increased by 6.26%, 12.71% and 14.40% respectively, and the chewiness of the products increased by 4.23%, 14.51% and 14.55% respectively, indicating that adding vegetable oil pre-emulsion to the formula can improve the texture properties of the product, and the addition of modified gum arabic to the pre-emulsion slightly improves the texture properties of the product on this basis.

[0028] The present invention aims to solve the problem of oxidative rancidity caused by substitution of vegetable oil in low-fat Western-style emulsified sausages. Gallic acid-modified gum arabic-myofibrillar protein composite pre-emulsion is added to the product formula to replace animal fat to prepare a modified Western-style emulsified sausage, with the aim of improving the quality characteristics of the Western-style emulsified sausage and the oxidative stability during the storage period. The myofibrillar protein-modified gum arabic composite emulsion is prepared by covalently grafting phenolic acid onto gum arabic through a laccase-catalyzed mediation method to prepare a modified gum arabic with a high level of antioxidant activity. The modified gum arabic is then combined with myofibrillar protein to perform composite emulsification of vegetable oil to obtain a modified gum arabic composite pre-emulsion. Compared with traditional Western-style emulsified sausages prepared with animal oil, the modified gum arabic composite pre-emulsion can effectively inhibit the formation of oil oxidation products. The modified Western-style emulsion with the modified gum arabic composite pre-emulsion can maintain long-term good oxidative stability during low-temperature storage.

[0029] Compared with traditional Western-style emulsified sausages prepared with animal oil, the improved Western-style emulsified sausages prepared with modified gum arabic composite emulsion instead of animal fat had the highest sensory score, among which the taste, juiciness and flavor scores were more prominent, indicating that the improved product formula can gain more favor from consumers. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] 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.

[0031] Figure 1 This is a comparison chart of the brightness and chromaticity values ​​of the improved Western-style emulsified sausage of the present invention and the traditional Western-style emulsified sausage.

[0032] Figure 2 This is a comparison chart of the texture characteristics of the improved Western-style emulsified sausage of the present invention and the traditional Western-style emulsified sausage.

[0033] Figure 3This is a comparison chart of the changes in TBARS values ​​of the improved Western-style emulsified sausage of the present invention and the traditional Western-style emulsified sausage during a 13-day storage period.

[0034] Figure 4 This is a comparison chart of the sensory scores of the improved Western-style emulsified sausage of the present invention and the traditional Western-style emulsified sausage.

[0035] Figure 5 Changes in TBARS values ​​of composite emulsions at different oxidation times. The three modified gum arabic treatments grafted with phenolic acids were ferulic acid-grafted gum arabic (FA-AG), caffeic acid-grafted gum arabic (CA-AG), and gallic acid-grafted gum arabic (GA-AG), while the control group was natural gum arabic (AG) without phenolic acid grafting. DETAILED DESCRIPTION

[0036] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0037] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other. Example

[0038] Production process of traditional Western-style emulsified sausage:

[0039] (1) Raw material preparation and processing: Select fresh longissimus dorsi muscle of pig, remove fat and connective tissue, mince with a meat grinder at 4℃, and set aside for use.

[0040] (2) Add ingredients: Weigh the ingredients according to the percentage of the total meat, including salt 1-3%, sugar 5-7%, MSG 0.1-0.5%, white pepper 0.1-0.5%, light soy sauce 1-5%, cooking wine 1-3%, five-spice powder 0.1-0.5%, phosphate 0.1-0.5%, and some crushed ice.

[0041] (3) Meat emulsification: Traditional Western-style emulsified sausages are prepared by adding 20% ​​minced pork back fat according to the percentage of the total meat. First, chop the pork loin with the ingredients and 1 / 3 of crushed ice for 1 min. After pausing for 2 min, add the pork back fat and 1 / 3 of crushed ice and chop again for 1 min. Finally, add the remaining crushed ice and chop for 3 min (the final chopping temperature does not exceed 10 °C).

[0042] (4) Filling and steaming: Use a sausage stuffer to fill the emulsified meat into the casing, tie the two ends of the casing tightly, and put it into boiling water for cooking.

[0043] (5) Vacuum packaging: After cooking, the emulsified sausage is cooled to room temperature and packaged using a vacuum packaging machine. Example

[0044] The production process of improved Western-style emulsified sausage prepared by replacing animal fat with myofibrillar protein single emulsion:

[0045] (1) Raw material preparation and processing: Select fresh longissimus dorsi muscle of pig, remove fat and connective tissue, mince with a meat grinder at 4℃, and set aside for use.

[0046] (2) Add ingredients: Weigh the ingredients according to the percentage of the total meat, including salt 1-3%, sugar 5-7%, MSG 0.1-0.5%, white pepper 0.1-0.5%, light soy sauce 1-5%, cooking wine 1-3%, five-spice powder 0.1-0.5%, phosphate 0.1-0.5%, and some crushed ice.

[0047] (3) Preparation of myofibrillar protein pre-emulsion: Disperse myofibrillar protein in buffer to prepare a 1% myofibrillar protein solution. Add vegetable oil at a ratio of 20% (w / w) to the myofibrillar protein single emulsion and homogenize at 10,000 × g for 1 min to obtain the myofibrillar protein single emulsion. All the above operations were carried out at 4°C.

[0048] (4) Meat emulsification: Add 20% myofibrillar protein emulsion according to the percentage of total meat to the modified Western-style emulsified sausage. Chop the pork tenderloin, ingredients and crushed ice for 1 minute. After pausing for 2 minutes, add the myofibrillar protein emulsion and chop for 3 minutes (the final chopping temperature does not exceed 10°C).

[0049] (5) Filling and steaming: Use a sausage stuffer to fill the emulsified meat into the casing, tie the two ends of the casing tightly, and put it into boiling water for cooking.

[0050] (6) Vacuum packaging: After cooking, the emulsified sausage is cooled to room temperature and packaged using a vacuum packaging machine.

[0051] To prepare myofibrillar protein in this example, pre-cut longissimus dorsi muscle was thawed at 4°C. After removing connective tissue, the muscle was cut along the grain and placed in a tissue grinder. Four volumes of phosphate buffer (10 mM Na₂HPO₄·12 H₂O, 0.1 M NaCl, 2 mM MgCl₂·6 H₂O, 1 mM EGTA, pH 7.0) were added to the grinder and the mixture was minced at a constant speed for 1 minute. The resulting homogenate was centrifuged, and the supernatant was decanted to collect the precipitate. Four volumes of 0.1 M NaCl solution were then added to the precipitate, which was then minced and filtered to remove excess fibrous tissue. Following the above procedure, centrifugation was performed and the precipitate, which is the myofibrillar protein, was obtained. Example

[0052] The production process of improved Western-style emulsified sausage prepared by using natural gum arabic composite emulsion instead of animal fat:

[0053] (1) Raw material preparation and processing: Select fresh longissimus dorsi muscle of pig, remove fat and connective tissue, mince with a meat grinder at 4℃, and set aside for use.

[0054] (2) Add ingredients: Weigh the ingredients according to the percentage of the total meat, including salt 1-3%, sugar 5-7%, MSG 0.1-0.5%, white pepper 0.1-0.5%, light soy sauce 1-5%, cooking wine 1-3%, five-spice powder 0.1-0.5%, phosphate 0.1-0.5%, and some crushed ice.

[0055] (3) Preparation of natural gum arabic composite pre-emulsion: Myofibrillar protein (2%, w / w, in the aqueous phase of the primary emulsion) and natural gum arabic (1.2%, w / w, in phosphate buffer) were stirred and hydrated at a ratio of 1:1 to prepare a composite solution of 1% myofibrillar protein + 0.6% natural gum arabic. Vegetable oil was added to the composite solution at a ratio of 20% (w / w), and the mixture was homogenized at 10,000 × g for 1 min to obtain a myofibrillar protein-natural gum arabic composite emulsion. All the above operations were carried out at 4°C.

[0056] (4) Meat emulsification: Add 20% natural gum arabic compound pre-emulsion according to the percentage of total meat to the modified Western-style emulsified sausage, chop the pork tenderloin, ingredients and crushed ice for 1 min, pause for 2 min, then add the natural gum arabic compound pre-emulsion and chop for 3 min (the final chopping temperature does not exceed 10 °C).

[0057] (5) Filling and steaming: Use a sausage stuffer to fill the emulsified meat into the casing, tie the two ends of the casing tightly, and put it into boiling water for cooking.

[0058] (6) Vacuum packaging: After cooking, the emulsified sausage is cooled to room temperature and packaged using a vacuum packaging machine. Example

[0059] The production process of improved Western-style emulsified sausage prepared by using modified gum arabic composite emulsion to replace animal fat:

[0060] Repeat the above steps, replacing the natural gum arabic composite pre-emulsion in Example 3 with the modified gum arabic composite pre-emulsion.

[0061] To prepare the modified gum arabic in this example, 1 g of gum arabic was weighed and dissolved in 45 mL of phosphate buffer (0.2 mol / L, pH 7.5). A methanol solution (5 mL) containing phenolic acids (50 mM) and laccase (15 LAMU / g) were then added to the solution. The mixed solution was placed in a magnetic stirring reactor (constant speed) and reacted under atmospheric conditions (without dissolved oxygen limitation) for 4 h. An equal volume of ethanol was then added to the solution to terminate the reaction. The mixed solution was centrifuged to remove water-insoluble substances. The ethanol and some water were then removed using a rotary evaporator at 40°C to 50°C. The concentrated solution obtained by rotary evaporation was dialyzed against ultrapure water using a biotechnology-grade dialysis membrane to remove excess salts. The purified solution was then freeze-dried for 72 h. The resulting modified gum arabic powder was sealed and stored dry until use.

[0062] Gallic acid, which has high antioxidant activity, was selected for grafting modification of gum arabic to demonstrate the application value of modified gum arabic in product formulations. However, the grafted phenolic acid in the modified gum arabic described herein is not limited to the gallic acid selected in the present experiments; any plant-derived phenolic substance can serve as a substrate for laccase-catalyzed modification.

[0063] The quality of the improved Western-style emulsified sausages (Examples 2-4) of the present invention and the traditional Western-style emulsified sausage (Example 1) of the control group were analyzed. The results are as follows:

[0064] (1) Comparison of brightness and chromaticity between improved and traditional Western-style emulsified sausages

[0065] like Figure 1 As shown in the figure, compared with traditional Western-style emulsified sausages made with animal oil, the brightness value of the product was significantly improved after replacing animal fat in the emulsified sausage formula with a pre-emulsion made with vegetable oil (P<0.05). This is because the addition of a pre-emulsion made with vegetable oil as the oil phase during the processing of Western-style emulsified sausages causes the oil phase to form uniform and fine droplets dispersed throughout the product system, increasing the area of ​​reflected light.

[0066] When a composite emulsion prepared with modified gum arabic was added to the product to replace animal fat, the experimental results showed a significant increase in brightness and a significant decrease in chromaticity (P < 0.05). This was attributed to the fully exerted antioxidant activity of the composite emulsion prepared with modified gum arabic during the gelation process, preventing color changes due to excessive oxidation of proteins and oils. The addition of a single emulsion of myofibrillar protein and a composite emulsion of natural gum arabic had no significant effect on product color. However, the addition of a composite pre-emulsion of gallic acid-modified gum arabic showed a trend toward reducing the color of the emulsified sausage, presumably due to the interaction between phenolic acids and myoglobin and fat molecules in the meat emulsion.

[0067] (2) Comparison of cooking loss between improved Western-style emulsified sausage and traditional Western-style emulsified sausage

[0068] Compared with traditional Western-style emulsified sausages prepared with animal oil, the addition of a myofibrillar protein emulsion, a natural gum arabic composite pre-emulsion, and a modified gum arabic composite pre-emulsion reduced the product's cooking loss by 28.75%, 40.37%, and 43.43%, respectively. These results suggest that replacing animal fat with a vegetable oil pre-emulsion can improve the yield of emulsified sausages. The addition of a single myofibrillar protein emulsion encapsulates oil within protein droplets, and the emulsion gel forms a tight network structure after thermal induction, enhancing the product's ability to retain juice. The addition of a natural gum arabic composite emulsion promotes interaction between natural gum arabic and myofibrillar protein within the product system, synergistically improving the stability of the product's internal structure and preventing juice loss during processing. There was no significant difference in cooking loss between modified and natural gum arabic (P>0.05), indicating that modified gum arabic does not affect the cross-linking between gum arabic and myofibrillar protein within the system.

[0069] (3) Comparison of the texture characteristics of improved Western-style emulsified sausage and traditional Western-style emulsified sausage

[0070] The texture characteristics of the product were determined using the full texture analysis method. The results are shown in Table 1 and Figure 2 The results are shown in Figure 3. The hardness of the products prepared with myofibrillar protein emulsion, natural gum arabic composite pre-emulsion, and modified gum arabic composite pre-emulsion increased by 6.26%, 12.71%, and 14.40%, respectively; the elasticity of the products increased by 12.50%, 21.47%, and 24.04%, respectively; and the chewiness of the products increased by 4.23%, 14.51%, and 14.55%, respectively. These results indicate that replacing animal fat with vegetable oil pre-emulsion improves the textural characteristics of the product, resulting in higher hardness and chewiness. This is because the encapsulation of the oil phase in the emulsion helps form a more ordered network structure in the product, providing some support for the product structure. The addition of gum arabic to the pre-emulsion enhances the interaction between protein molecules, further building a more stable meat protein gel network structure. The addition of gallic acid-modified gum arabic slightly improves the product's textural properties, which is related to the protective effect of phenolic acids on proteins, preventing functional damage caused by oxidation during processing.

[0071] Table 1 Texture characteristics of Western-style emulsified sausages prepared with different formulas

[0072]

[0073] Different lowercase letters in the table indicate significant differences between different treatment groups at the same storage time ( P <0.05).

[0074] (4) Comparison of oil oxidation stability between improved Western-style emulsified sausage and traditional Western-style emulsified sausage

[0075] In order to monitor the changes in fat content in Western-style emulsified sausages during long-term storage at low temperatures, the emulsified sausages were vacuum-packed and stored at 4°C for 13 days, and samples were taken at intervals to measure the TBARS value of the product. Figure 3 As shown, the fat oxidation stability of Western-style emulsified sausage prepared with animal oil is the worst, and the TBARS value increases exponentially during the storage period, indicating that traditional Western-style emulsified sausage prepared with animal oil is more susceptible to oxidative damage.

[0076] The effect of replacing animal fat with a single myofibrillar protein emulsion on TBARS was similar to that of traditional Western-style emulsified sausage, but TBARS was significantly lower throughout the entire process. Vegetable oils contain more unsaturated fatty acids and are theoretically more susceptible to oxidative damage, but experimental data showed the opposite. This is attributed to the use of myofibrillar protein pre-emulsification technology in vegetable oil pre-emulsions. This protein is coated on the surface of the oil droplets, using amino acid active groups to bind to free radicals in the system, preventing most oxygen free radical damage to the oil.

[0077] Compared to Western-style emulsified sausages prepared with a single myofibrillar protein emulsion, the addition of a natural gum arabic emulsion failed to further improve the product's lipid oxidation stability. The difference in antioxidant activity between the two groups only occurred during the mid-to-late stages of oxidation, when the single protein emulsion was no longer able to protect against the rancidity of the fat caused by prolonged oxidation. The excessive production of secondary oxidation products in the fat led to a rapid increase in the TBARS value. The failure of the natural gum arabic emulsion to improve the product's lipid oxidative rancidity during storage is due to the fact that natural gum arabic itself does not possess antioxidant activity.

[0078] Modified gum arabic significantly inhibited the TBARS value of emulsified sausage throughout storage. Notably, at the end of storage (day 13) for emulsified sausage prepared with vegetable oil pre-emulsion completely replacing pork back fat, the TBARS value of the group treated with gallic acid-modified gum arabic was only 32.8% of that of the group treated with myofibrillar protein alone, demonstrating that modified gum arabic can address the problem of oxidative deterioration during storage. Therefore, Western-style emulsified sausage prepared with gallic acid-modified gum arabic exhibits stable antioxidant activity throughout storage, suggesting its potential as a functional additive in minced meat products.

[0079] (5) Comparison of sensory scores between improved Western-style emulsified sausage and traditional Western-style emulsified sausage

[0080] In order to determine whether the modified gum arabic composite emulsion can successfully replace animal fat in emulsion-type meat products and evaluate the overall quality of the modified emulsified sausage, this paper used sensory evaluation to predict consumer acceptance of the modified emulsified sausage. The results are as follows: Figure 4 As shown. The comprehensive evaluation of the sensory items of the emulsified sausage prepared with animal fat is low, indicating that the traditional Western-style emulsified sausage prepared with animal fat has not received unanimous preference from the evaluators. When the animal fat is completely replaced by the vegetable oil pre-emulsion, the taste, flavor and juiciness of the product are significantly improved. The juiciness score is consistent with the result of the cooking loss measurement, indicating that after the pre-emulsion is completely replaced, more water can be retained in the product system. The product has more juice when chewing and the meat is smooth, which naturally obtains a higher taste score. The composite emulsion prepared by gallic acid modified gum arabic completely replaces animal fat and presents the highest flavor score. It delays the oxidation process of the product through its antioxidant activity, so the flavor substances of the product can be retained to the greatest extent. The present invention proposes to add a modified gum arabic composite emulsion to the formula of traditional Western-style emulsified sausage to replace animal fat. Judging from the statistical data of the sensory evaluation, the new formula emulsified sausage prepared with modified gum arabic has higher sensory attributes, which may become a driving factor for consumers to purchase the new formula Western-style emulsified sausage.

[0081] (6) Comparison of the antioxidant activity of three modified gum arabic-myofibrillar protein composite emulsions

[0082] The present invention also conducted a comparative test on the antioxidant activity of composite emulsions formed by modified gum arabic grafted with different phenolic acids and myofibrillar protein. The three modified gum arabic treatment groups grafted with phenolic acids were ferulic acid grafted gum arabic (FA-AG), caffeic acid grafted gum arabic (CA-AG), and gallic acid grafted gum arabic (GA-AG), while the control group was natural gum arabic (AG) without phenolic acid grafting. The results are as follows: Figure 5 As shown, when gallic acid-grafted gum arabic (GA-AG) is used, the TBARS value of the composite emulsion is the lowest, indicating that gallic acid-modified gum arabic can effectively inhibit the formation of oil oxidation products in the composite emulsion, which is why the modified gum arabic can exert antioxidant activity when used in Western-style emulsified sausage products. Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. Application of a myofibrillar protein-modified gum arabic composite emulsion in the preparation of a Western-style emulsified sausage, characterized in that: A myofibrillar protein-modified gum arabic composite emulsion is added at a mass ratio of 20% of the total meat, and the sausage is filled and steamed to obtain a Western-style emulsified sausage; the myofibrillar protein-modified gum arabic composite emulsion comprises myofibrillar protein and modified gum arabic; the myofibrillar protein is a myofibrillar protein solution with a mass percentage of 2%; The modified gum arabic is prepared into a modified gum arabic solution with a mass percentage of 1.2% using phosphate buffer; The preparation method of the myofibrillar protein-modified gum arabic composite emulsion comprises: mixing a 2% by mass myofibrillar protein solution and a 1.2% by mass modified gum arabic solution in a volume ratio of 1:1, adding 20 wt% of vegetable oil, and homogenizing at a high speed of 8000-12000×g to obtain the myofibrillar protein-modified gum arabic composite emulsion; The method for preparing myofibrillar protein comprises: cutting the longissimus dorsi muscle of a pig, removing connective tissue, cutting the muscle into pieces along the grain, and blending the pieces at 4°C, adding the pieces to a phosphate buffer solution and blending the pieces uniformly, centrifuging the resulting homogenate, decanting the supernatant, and collecting a precipitate, adding a NaCl solution to the precipitate, blending the homogenate, filtering to remove excess fibrous tissue, and centrifuging the filtrate to collect the precipitate to obtain myofibrillar protein; the phosphate buffer solution comprises: 10 mM Na2HPO4•12H2O, 0.1 M NaCl, 2 mM MgCl2•6H2O, and 1 mM EGTA, with a pH of 7.0; The preparation method of the modified gum arabic comprises: dissolving gum arabic in phosphate buffer, sequentially adding a methanol solution containing gallic acid and laccase to the solution, placing the mixed solution in a magnetic stirring reactor for reaction under atmospheric conditions for 4 hours, adding an equal volume of ethanol to the solution to terminate the reaction, centrifuging the mixed solution, and removing ethanol and part of the water using a rotary evaporator at 40-50° C., dialyzing and purifying the concentrated solution obtained by rotary evaporation, and then freeze-drying it for 72 hours to obtain the modified gum arabic.

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