Preparation method of low-fat mutton soup

Abstract

The application discloses a preparation method of low-fat mutton soup and belongs to the technical field of food processing. The preparation method of the mutton soup comprises the following steps: selecting fresh mutton, removing the visible excess fat on the surface, compounding shank meat and rib meat, and then boiling the compound meat in water; additionally, boiling rib bones and auxiliary materials in water to obtain auxiliary material soup juice; cooling the obtained mutton soup to 30-35 DEG C and standing to make the fat solidify and separate out, removing the solidified fat on the surface of the soup liquid, and obtaining a low-fat mutton soup base; and the like steps of seasoning, filling, sealing, sterilization treatment and the like to obtain the low-fat mutton soup. The shank meat and the rib meat are compounded and combined with the cooling and standing fat-removing process, so that the fat content of the mutton soup is reduced, and meanwhile, the product quality is maintained. The solidified fat obtained in the cooling and fat-removing process is subjected to enzymatic reaction to prepare mutton-derived lipids rich in diglycerides, and is backfilled into the low-fat mutton soup base after emulsification treatment, which is helpful to further improve the flavor and color of the mutton soup and improve the acceptance of the mutton soup.

Description

Technical Field

[0001] This invention relates to a method for preparing low-fat mutton soup, belonging to the field of food processing technology. Background Technology

[0002] Lamb soup is an important category of traditional meat products, and its flavor and quality are closely related to its fat content, fat dispersion state, and the composition of aroma and flavor compounds in the broth. In traditional simmering processes, the fat from the lamb meat and bones is gradually released and dispersed in the broth, forming a lipid system with certain emulsifying characteristics. This system significantly contributes to the final color, aroma, and rich taste of the product. However, the relatively high fat content of traditional lamb soup is increasingly becoming a constraint on its adaptation to modern low-fat food consumption trends. How to reduce fat content while maintaining good sensory quality has become a pressing technical problem to be solved in this field.

[0003] Currently, there is a certain research foundation for techniques to reduce fat content in meat broth systems. Existing technologies mainly focus on the following aspects: First, raw material selection and pretreatment, by using low-fat cuts or removing some visible fat through physical methods to reduce fat content from the source. However, using only a single lean cut often results in a thin broth texture and tough meat. Second, physical separation methods are used during or after cooking, such as skimming off surface oil, centrifugation, or adsorption degreasing. These methods can effectively reduce total fat content, but if the degreasing degree is too high, the color, aroma, and overall taste of the broth will also deteriorate significantly. Third, solidified fat is removed after cooling, utilizing the property of lipids to solidify at low temperatures for separation. This method is simple to operate and has a high degreasing efficiency, but it also faces the problem of flavor loss due to excessive fat removal. Overall, existing technical solutions generally suffer from a common defect: it is difficult to achieve a good balance between the degree of fat reduction and sensory quality. That is, while achieving a significant reduction in fat, it is often accompanied by problems such as insufficient aroma, bland taste or poor color of the soup, making it difficult to meet the requirements of low fat and the sensory quality of traditional mutton soup.

[0004] Therefore, there is still a need in the art to provide a preparation method that can effectively reduce the fat content of mutton soup while better preserving its sensory qualities such as color, aroma and taste. Summary of the Invention

[0005] To address the aforementioned technical problems, the purpose of this invention is to provide a method for preparing low-fat mutton soup. By rationally proportioning mutton ingredients and combining this with cooling and settling after boiling to remove excess fat, the fat content of the mutton soup is reduced, while minimizing the adverse effects on the product's taste caused by using only lean meat or excessive fat removal. This results in a low-fat mutton soup with better color, aroma, and taste.

[0006] To achieve the above objectives, the present invention first provides a method for preparing low-fat mutton soup, comprising the following steps: (1) Raw material screening and pretreatment: Remove the excess fat visible on the surface of the mutton, and mix the mutton leg meat and mutton ribs in a mass ratio of 1:0.5 to 1:2 and cut them into pieces; (2) Cooking the raw materials: Add the diced lamb leg meat and lamb ribs from step (1) to water and cook at high temperature. After cooking, drain the lamb meat and the broth. (3) Cooling and skimming: Cool the raw broth obtained in step (2) to 30-35°C and let it stand to allow the mutton fat to separate and solidify; remove the solidified fat from the surface of the broth to obtain defatted raw broth. (4) Preparation of auxiliary ingredients: Add lamb bones, ginger, angelica, cinnamon, galangal, cardamom and fennel to water and cook to obtain auxiliary ingredient broth; (5) Mixing the broth: Mix the defatted raw material broth obtained in step (3) with the auxiliary material broth obtained in step (4), add salt and MSG to obtain the seasoned broth; (6) Filling, sealing and sterilization: The cooked mutton obtained in step (2) and the seasoning broth obtained in step (5) are filled, sealed and sterilized to obtain low-fat mutton soup.

[0007] In one embodiment of the present invention, the mutton used in step (1) is healthy mutton from a non-epidemic area, and each batch of raw materials should have a veterinary quarantine certificate issued by the animal disease prevention department of the place of origin. Upon arrival, the core temperature of the raw materials should be inspected; the core temperature of frozen raw materials should be below -12℃, and the core temperature of fresh raw materials should be below 7℃.

[0008] In one embodiment of the present invention, in step (2), the mass ratio of the mixture of cut lamb leg meat and lamb ribs to water is 1:2~3, and the high-temperature cooking is carried out at 90~100℃ for 10~30 minutes, preferably at 100℃ for 10 minutes.

[0009] In one embodiment of the present invention, in step (2), water is first heated to 60~80°C and then the diced lamb leg meat and lamb ribs are added, and the mixture is heated to boiling and kept cooking for 10~30 minutes.

[0010] In one embodiment of the present invention, in step (4), the mass ratio of the lamb bone to water is 1:9~11, and the mass ratio of the lamb bone to ginger, angelica, cinnamon, galangal, cardamom and fennel is 99~101:1.

[0011] In one embodiment of the present invention, in step (5), the mass ratio of the defatted raw material broth to the auxiliary material broth is 1:1, the mass of added edible salt accounts for 5-6‰ of the total mass of the mixed broth, and the mass ratio of edible salt to monosodium glutamate is 1.9-2.1:1.

[0012] In one embodiment of the present invention, in step (6), the sterilization equipment used is a sterilizing autoclave. The canned goods should be sterilized using a sterilizing autoclave within 1 hour after sealing. The sterilization process should be strictly carried out in accordance with the sterilization process operating procedures, and the initial temperature before sterilization should reach 70℃.

[0013] In one embodiment of the present invention, in step (6), sterilization is carried out at 121°C. The specific sterilization process is as follows: first, the temperature is raised to 121°C within 15 minutes, and then kept at the temperature for 20 minutes before cooling. The cooling time is 25 minutes, and the pressure is not lower than 0.15 MPa when the temperature starts to drop.

[0014] In one embodiment of the present invention, after removing the solidified fat in step (3), the step further includes the step of backfilling the obtained defatted raw material broth with sheep-derived diglyceride lipids.

[0015] In one embodiment of the present invention, the amount of sheep-derived diglyceride lipids added is in a mass ratio of 0.18~0.22 g / 100g to the defatted raw material broth.

[0016] In one embodiment of the present invention, the sheep-derived diglyceride lipid is preferably prepared by using the coagulated fat removed in step (3) as raw material and preparing sheep-derived lipid rich in diglycerides through an enzymatic reaction.

[0017] In one embodiment of the present invention, the enzymatic reaction is carried out using Novozyme 435 as a lipase and the mixed fatty acids and glycerol obtained in step S2 as substrates.

[0018] In one embodiment of the present invention, the specific preparation steps of the sheep-derived diglyceride lipid are as follows: S1. Refining mutton fat: After melting mutton fat and removing impurities, refined mutton fat is obtained through degumming, decolorization and deodorization. S2. Preparation of mixed fatty acids: The refined mutton fat obtained in step S1 is saponified and hydrolyzed, and the saponified product is then acidified to obtain mixed fatty acids.

[0019] S3. Preparation of diglycerides: Using glycerol and the mixed fatty acids from step S2 as substrates, Novozyme 435 as lipase, and the mixed fatty acids and glycerol obtained in step S2 as substrates, an enzymatic reaction was carried out. The enzyme was separated by centrifugation to obtain sheep-derived diglyceride lipids.

[0020] In one embodiment of the present invention, in step S1, the degumming process involves melting solidified mutton fat at 65-75°C to remove impurities and obtain crude mutton fat. The crude mutton fat is then heated in a water bath to 65-75°C with continuous stirring. Phosphoric acid (80% by volume), accounting for 1% of the mutton fat's volume, is slowly added and stirred until homogeneous. The mixture is then heated at 65-70°C for 1-5 minutes, followed by centrifugation at 3500-4500 r / min for 15-25 minutes. The oil floating on the top layer is the degummed mutton fat. The degummed mutton fat is then heated in a water bath to 70°C, and activated clay, accounting for 3% of the mutton fat's weight, is added. After stirring for 20-25 minutes, it is centrifuged at 3500-4500 r / min for 15-25 minutes. The oil floating on the top layer is the decolorized mutton fat. The decolorized mutton fat is placed in a round-bottom flask and subjected to vacuum treatment using a rotary evaporator at 55°C for 20-30 minutes to obtain deodorized mutton fat.

[0021] In one embodiment of the present invention, in step S2, refined mutton fat is added to a 1 mol / L NaOH-ethanol solution at a volume ratio of 1:2 to 1:5, and magnetically stirred for 20 to 30 minutes until completely dissolved. The solution is then transferred to a 1000 mL three-necked flask and saponified under nitrogen protection by reflux in a water bath for 1 to 2 hours to obtain a saponified solution. The ethanol is distilled off under reduced pressure, and water is added to completely dissolve the saponified product. The solution is then acidified to pH 2 to 3 with 10% HCl under constant temperature and speed stirring. Hexane is added for extraction, and the solution is washed with warm water until neutral. The solvent is distilled off under reduced pressure, and anhydrous sodium sulfate is added for dehydration. The solution is then filtered to obtain mixed fatty acids.

[0022] In one embodiment of the present invention, in step S3, the mass ratio of mixed fatty acids to glycerol in the substrate is 1:0.5 to 1:1.5, preferably 1:1 to 1:1.5; the added mass of Novozyme 435 accounts for 1.5 to 4% of the mass of sheep fat, preferably 2.5 to 4%; the enzymatic hydrolysis temperature is 50 to 65°C, preferably 50 to 55°C; the enzymatic hydrolysis time is 6 to 12 hours, preferably 8 hours; and the enzyme activity of Novozyme 435 is ≥9000 PLU / g.

[0023] In one embodiment of the present invention, the backfilled sheep-derived diglyceride lipids are obtained by emulsifying the sheep-derived diglyceride lipids and then adding them to the low-fat mutton soup base. The emulsification process is carried out at a speed of 5000-10000 rpm for 5-15 minutes.

[0024] The present invention also provides a low-fat mutton soup product prepared according to the above preparation method.

[0025] Beneficial effects: 1. This invention, by rationally combining lamb leg meat and lamb rib meat, and by cooling and settling after boiling to remove fat, can reduce the fat content of lamb soup while minimizing the adverse effects of using only lean meat on the product's taste, thus balancing low-fat requirements with the product's color, aroma, and taste.

[0026] 2. The present invention adopts a cooling and static degreasing method, which causes some of the fat in the soup to solidify and precipitate under low temperature conditions and is removed by physical means. The process is simple and easy to integrate with the existing mutton soup production process.

[0027] 3. The basic low-fat preparation method of this invention does not require the addition of exogenous lipids. Low-fat mutton soup can be obtained by rationally combining lamb leg meat and lamb ribs and cooling and settling to remove fat, providing a feasible basic process route for the preparation of low-fat mutton soup. Based on the basic low-fat preparation method, the solidified fat obtained during the cooling and degreasing process is reused to prepare sheep-derived lipids rich in diglycerides through enzymatic reaction, which are then further added back to the low-fat mutton soup, effectively improving the color, aroma, and taste of the product after low-fat treatment.

[0028] 4. This invention provides a basic low-fat preparation scheme and a further implementation scheme for sheep-derived diglyceride lipid refilling. The appropriate process route can be selected according to product requirements, and further technical options are provided for quality optimization of low-fat mutton soup while reducing the fat content of the product. Attached Figure Description

[0029] Figure 1 The effects of different factors on the diglyceride production rate by enzymatic hydrolysis; Figure 2 Electronic nose images of mutton soup from Examples 1-2 and Comparative Examples 1-6; Figure 3 Sensory evaluation diagrams of the mutton soup from Examples 1-2 and Comparative Examples 1-6. Detailed Implementation

[0030] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to embodiments and accompanying drawings.

[0031] The Novozyme 435 used in the embodiments and comparative examples of this invention is UPG ET200, with an enzyme activity of ≥9000 PLU / g, purchased from Novozymes Biotechnology Co., Ltd.

[0032] Detection method: 1. Determination of diglyceride content Diglyceride content was determined by high-performance liquid chromatography with a refractive index detector (HPLC-RID). Chromatographic conditions: column: silica gel column (250 mm × 4.6 mm, 5 μm); mobile phase: hexane-isopropanol-formic acid (85:15:0.1, v / v / v); flow rate: 1.0 mL / min; column temperature: 35℃; detector: refractive index detector (RID), temperature: 40℃; injection volume: 10 μL. Samples were weighed, and lipids were extracted with a hexane-isopropanol (3:1, v / v) mixed solvent. The extracted lipids were filtered through a 0.45 μm organic phase filter before analysis. Diglyceride content was calculated using the external standard method.

[0033] 2. Fat content determination The determination was performed according to the second method of acid hydrolysis in GB 5009.6-2016 "National Food Safety Standard - Determination of Fat in Food". After thoroughly mixing the mutton soup sample (including mutton and broth), weigh 3 g to 5 g of the mixed sample (accurate to 0.001 g) and place it in an Erlenmeyer flask (250 mL).

[0034] 3. Odor Profile Analysis Weigh 3 mL of mutton broth and place it in a 20 mL sealed headspace vial. Extract the volatiles at a constant rate of 300 mL / min. After testing for 60 s, rinse with clean air for 180 s. After the baseline stabilizes, proceed with the next test.

[0035] The electronic nose is equipped with 10 standard sensor probes, which are sensitive to aromatic compounds (W1C), nitrogen oxides (W5S), ammonia and aromatic compounds (W3C), hydrides (W6S), alkenes and aromatic compounds (W5C), methyl compounds (W1S), sulfides (W1W), alcohols, aldehydes and ketones (W2S), organosulfur compounds (W2W), and long-chain alkanes (W3S).

[0036] 4. Colorimetric analysis The color difference between samples was measured using a colorimeter. After calibration with a white calibration plate, the brightness (L) of the samples was recorded. ), red (a ), yellow value (b) ), saturation (c ) and hue angle (h ).

[0037] 5. Sensory evaluation methods (1) Formation and training of the evaluation team We are recruiting 12 experienced sensory evaluators (half male and half female, aged 22-45) with extensive experience in meat product sensory evaluation. All evaluators must be in good health, have a keen sense of smell and taste, be free from illnesses such as colds or allergies that could affect sensory judgment, be non-smokers, and have no aversion to mutton or spices. Prior to the evaluation, evaluators will receive specialized training to familiarize them with the traditional quality characteristics of mutton soup (such as "milky white," "rich aroma," and "tender but not sticky") as well as the sensory requirements for low-fat mutton soup, and to standardize the evaluation criteria for each indicator.

[0038] (2) Evaluation environment Sensory evaluations were conducted in a standard sensory evaluation room. The room temperature was controlled at 20℃–25℃, relative humidity at 50%–60%, and there were no unpleasant odors. The lighting was sufficient and uniform. Evaluators conducted their evaluations in separate sensory evaluation cubicles to avoid mutual interference.

[0039] (3) Sample preparation and presentation The canned mutton soup samples prepared in each embodiment and comparative example were heated in a water bath to 65℃~70℃, thoroughly mixed, and then 50 mL was measured and poured into preheated white odorless ceramic cups (if containing meat chunks, 10 g of uniformly sized meat chunks were weighed and placed in each cup). Samples were coded with random three-digit numbers and presented in the order specified by the Williams Latin square design to eliminate order effects and carryover effects. Between tastings of two samples, evaluators were required to rinse their mouths with purified water and eat unsalted soda crackers to remove any aftertaste, with an interval of at least 3 minutes.

[0040] (4) Evaluation indicators and scoring criteria A weighted scoring method based on a percentage system was adopted, with a maximum score of 100 points. Combining the quality characteristics of mutton soup and the characteristics of low-fat products, a sensory evaluation system was established, comprising five dimensions: color (20 points), aroma (25 points), taste (25 points), texture and mouthfeel (20 points), and overall acceptability (10 points). Each evaluation indicator was first scored raw according to its corresponding maximum score. Then, the average raw score of each indicator was converted into a percentage score using the following formula: Indicator percentage score = Average raw score of indicator / Maximum score of that indicator × 100; Overall sensory score = Color percentage score × 20% + Aroma percentage score × 25% + Taste percentage score × 25% + Texture and mouthfeel percentage score × 20% + Overall acceptability percentage score × 10%. Specific scoring criteria are shown in the table below: Table 1 Sensory Evaluation Scoring Criteria

[0041] Example 1 A method for preparing low-fat mutton soup includes the following steps: (1) Raw material processing: Select 500g of fresh mutton, remove visible fat, mix mutton leg meat and mutton rib meat in a mass ratio of 1:1, and cut into uniformly sized pieces for later use. (2) Cooking the mutton: Add the drinking water to the cooking pot at a ratio of 1:2 (mutton to drinking water by weight), heat to 70°C, then add the mutton obtained in step (1), heat to boiling, and continue cooking for about 10 minutes. After cooking, remove the mutton and drain the broth for later use. (3) Cooling and standing the broth to remove fat: Cool the raw broth obtained in step (2) to 30-35°C, let it stand until the fat on the surface of the broth solidifies and then remove it to obtain a low-fat raw broth; (4) Broth preparation: Prepare the ingredients according to the mass ratio of drinking water, lamb bones, ginger, angelica, cinnamon, galangal, cardamom and fennel 1000:100:1:1:1:1:1:1. Boil the drinking water and add the lamb bones and auxiliary ingredients. Cook for 120 minutes to obtain the auxiliary ingredient broth.

[0042] (5) Preparation of auxiliary ingredients soup: Mix the low-fat raw material soup obtained in step (3) with the auxiliary ingredients soup obtained in step (4) at a mass ratio of 100:100, and add salt and MSG at a mass ratio of 1000:5:2.5 for the mixed soup, salt and MSG, mix evenly to obtain the seasoning soup.

[0043] (6) Canning, sealing and sterilization: Weigh the cooked mutton obtained in step (2) according to the canning requirements of 1.25 kg product and put it into cans; add the prepared broth obtained in step (5) and seal the cans. After sealing, sterilize in a sterilizing kettle. The sterilization temperature is 121℃, and the sterilization formula is 15'-20'-25', that is, heating for 15 min, constant temperature sterilization at 121℃ for 20 min, and cooling for 25 min. The cooling stage is controlled by back pressure. After sterilization, cool and clean, and after passing the inspection, low-fat mutton soup canned food is obtained.

[0044] Comparative Example 1: Preparation of Traditional Lamb Soup The difference between Comparative Example 1 and Example 1 is that the mutton soup obtained in step (3) is not cooled and allowed to stand at 30-35°C and the surface solidified fat is removed. Instead, the soup is directly mixed, seasoned, canned, sealed and sterilized. The remaining process conditions are the same as in Example 1.

[0045] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the mass ratio of lamb leg meat to lamb ribs in step (1) is 1:0.

[0046] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that the mass ratio of lamb leg meat to lamb ribs in step (1) is 1:2.

[0047] Example 2 The difference between Example 2 and Example 1 is that in step (3), after skimming off the solidified mutton fat from the top layer, the solidified mutton fat is prepared into mutton-derived diglyceride lipids by enzymatic hydrolysis. The obtained mutton-derived diglyceride lipids are then treated at 7500 rpm for 10 min and backfilled into the defatted mutton soup base at a mass ratio of 0.2 g / 100g to the defatted raw material broth to obtain the mutton soup base. The remaining steps and parameters are the same as in Example 1. The preparation method of the mutton-derived diglyceride lipids is as follows: S1. Refining of mutton fat: Solidified mutton fat is melted at 60℃ to remove impurities and obtain crude mutton fat. The crude mutton fat is heated to 70℃ in a water bath with constant stirring. Then, 1% (by volume) of phosphoric acid (80% by volume) is slowly added and stirred until homogeneous. The mixture is heated at 70℃ for 2 minutes, then centrifuged at 4000 rpm for 20 minutes. The oil floating on top is degummed mutton fat. The degummed mutton fat is heated to 70℃ in a water bath, and 3% (by weight) of activated clay is added. After stirring for 20 minutes, it is centrifuged at 4000 rpm for 20 minutes. The oil floating on top is decolorized mutton fat. The decolorized mutton fat is placed in a round-bottom flask and vacuum-treated at 55℃ using a rotary evaporator for 30 minutes to obtain deodorized mutton fat.

[0048] S2. Preparation of mixed fatty acids: Refined mutton fat was added to 1 mol / L NaOH-ethanol solution at a volume ratio of 1:4. After complete dissolution by magnetic stirring, the solution was transferred to a 1000 mL three-necked flask and saponified under nitrogen protection by reflux in a water bath for 2 hours to obtain a saponified solution. The ethanol was distilled off under reduced pressure, and water was added to completely dissolve the saponified product. The solution was acidified to pH 2.5 with 10% HCl under constant temperature and speed stirring. An equal volume of n-hexane was added for extraction, and the solution was washed with warm water until neutral. The solvent was distilled off under reduced pressure, and anhydrous sodium sulfate was added for dehydration. The solution was then filtered to obtain mixed fatty acids.

[0049] S3. Preparation of diglycerides: Mix fatty acids and glycerol in a small flask at a mass ratio of 1:1.2 and place in a constant temperature shaker at 51℃ to mix the reactants evenly. Add Novozyme 435 at 3.2% of the mass of sheep fat. After reacting for 6 hours, centrifuge to separate the enzymes and obtain sheep diglyceride lipids.

[0050] Before refilling sheep-derived diglycerides into mutton broth, the following experiment was designed to investigate the effect of enzymatic hydrolysis conditions on the diglyceride formation rate: ① In step S3, the mass ratio of glycerol to mixed fatty acids is fixed at 1:1, the enzymatic hydrolysis temperature is 50℃, and the enzymatic hydrolysis reaction time is 8h. The proportions of Novozyme 435 in the mutton fat mass are set to 1.5%, 2%, 2.5%, 3%, 3.5%, and 4%, respectively. ② In step S3, the mass ratio of glycerol to mixed fatty acids is fixed at 1:1, Novozyme 435 accounts for 3% of the mass of mutton fat, the enzymatic hydrolysis reaction time is 8h, and the enzymatic hydrolysis temperature is set at 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, 65℃ and 70℃ respectively. ③ In step S3, the reaction temperature is fixed at 50℃, Novozyme 435 accounts for 3% of the mass of mutton fat, the enzymatic hydrolysis reaction time is 8h, and the mass ratio of mixed fatty acids to glycerol is set to 1:0.5, 1:1, 1:1.5, 1:2, 1:2.5 and 1:3 respectively; ④ In step S3, the mass ratio of glycerol to mixed fatty acids is fixed at 1:1, Novozyme 435 accounts for 3% of the mass of mutton fat, the enzymatic hydrolysis temperature is 50℃, and the enzymatic hydrolysis reaction time is set to 2, 4, 6, 8, 10 and 12 h respectively.

[0051] Figure 1 The effects of Novozyme 435 addition amount, enzymatic hydrolysis temperature, substrate mass ratio, and enzymatic hydrolysis time on the diglyceride formation rate in the above experiments were presented. The results showed that controlling the Novozyme 435 addition amount to 3%~3.5% of the lanolin mass, the reaction temperature to 50~55℃, the mass ratio of mixed fatty acids to glycerol to 1:1~1:1.5, and the reaction time to more than 6 hours helped to significantly improve the diglyceride formation rate, making it reach more than 80%.

[0052] Comparative Example 4 The difference between Comparative Example 4 and Example 2 is that the amount of Novozyme 435 added in step S3 was changed to 2% of the mass of mutton fat.

[0053] Comparative Example 5 The difference between Comparative Example 5 and Example 2 is that the mass ratio of mixed fatty acids to glycerol was changed to 1:3.

[0054] Comparative Example 6 The difference between Comparative Example 6 and Example 2 is that the mass ratio of lamb leg meat to lamb ribs in step (1) is 1:0.

[0055] The obtained samples were tested for fat content, and the results are as follows: After employing the cooling skimming process, the total fat content of Examples 1 and 2 was 2.6 ± 0.3 g / 100 g and 2.8 ± 0.2 g / 100 g, respectively, both below 3 g / 100 g. Compared to the total fat content of Comparative Example 1 (4.6 ± 0.5 g / 100 g), the total fat content of Examples 1 and 2 decreased by approximately 43.5% and 39.1%, respectively.

[0056] In Comparative Example 3, the proportion of lamb ribs was relatively high. Under the same cooling and skimming process, the total fat content was 3.5±0.3 g / 100 g, which did not meet the low-fat requirements specified in the national standard GB 28050-2011. This indicates that the composition and ratio of lamb leg meat and lamb ribs can affect the fat content of the final product.

[0057] Although Comparative Examples 4 and 5 met the low-fat requirement in terms of total fat content, due to different enzymatic hydrolysis conditions, the DAG mass fractions in their lipid components were 68.2% and 48.4%, respectively, lower than the 88.3% in Example 2. This indicates that suitable enzymatic hydrolysis conditions are beneficial for increasing the relative DAG content in the product. After enzymatic hydrolysis of mutton fat and lipid backfilling, the mass fractions of diglycerides in the lipid components of Example 2 and Comparative Example 6 were 88.3% and 87.5%, respectively. Comparative Example 2 was prepared using whole lamb leg meat, with a total fat content of 2.3 ± 0.1 g / 100 g, but subsequent sensory evaluation results showed that its overall acceptability was low.

[0058] Table 2 Total Fat Content and DAG Ratio

[0059] Note: The low-fat standard refers to GB 28050-2011 "National Food Safety Standard - General Rules for Nutrition Labelling of Prepackaged Foods", which stipulates that the fat content of solid foods should be ≤3g / 100g; the DAG ratio is the ratio of the amount of lipid added from backfilled sheep DAG to the total fat content of the sample.

[0060] The colorimetric values ​​of each group of samples were measured, and the results are shown in Table 3.

[0061] Compared with Comparative Example 1, the L in Examples 1 and 2 The value has increased, a value and b The corresponding changes in the values ​​indicate that the mutton soup prepared using the method of this invention differs from traditional mutton soup in terms of overall color appearance. In Example 2, after backfilling with sheep-derived diglyceride lipids, its overall color index further changed compared to Example 1, and its overall color appearance was improved.

[0062] Compared to Example 1, Comparative Example 2, prepared from whole lamb leg meat, showed differences in its overall color index; combined with subsequent sensory evaluation results, the color acceptance of Comparative Example 2 was relatively low. After lipid refilling, the overall color of Comparative Example 6 was improved compared to Comparative Example 2, but it still differed from Example 2 to some extent.

[0063] Colorimetric data show that Comparative Example 3 has a higher b-value (yellow value) than Example 1 because the lamb ribs are higher in fat content than those in Example 1. Comparative Examples 4 and 5 have DAG percentages of 5.5% and 3.9%, respectively, and their overall colorimetric indices differ from those of Example 2. In Example 2, the DAG percentage is 7.1%, and its L... a b The scores were 43.06, 3.17, and 16.82, respectively, indicating that the overall color index was better than other samples. Combined with the sensory evaluation results, under the DAG preparation and backfilling conditions used in Example 2, the score reached 89 points, which is a relatively high level among all samples, indicating that the high DAG mass fraction of sheep-derived lipids used in backfilling is beneficial to improving the overall color performance of low-fat mutton soup.

[0064] Table 3. Colorimetric Analysis Results

[0065] The obtained samples were subjected to an electronic nose test, and the results are as follows: Figure 2 As shown, the electronic nose analysis results indicate that there are significant differences in the volatile odor response patterns of mutton soup samples under different raw material compositions and processing conditions, suggesting that different treatments alter the overall volatile odor profile of the samples. In Comparative Example 1, some sensor response values ​​are higher than in Example 1, indicating that the volatile odor response pattern of the sample changed after cooling and skimming treatment. This demonstrates that after the defatting treatment of this invention, the volatile odor response pattern and relative response intensity of the sample changed, and the original strong volatile odor characteristics were adjusted to a certain extent.

[0066] Samples composed of different raw materials also exhibited different odor response characteristics. The responses of the sensors in Comparative Example 3 varied; for example, the response values ​​of W3C and W6S increased slightly, while the changes in W1C and W5C were smaller or slightly decreased. This indicates that a high or low response value of the electronic nose sensor does not directly represent the quality of the odor. What truly affects sensory quality is the overall odor balance formed by different volatile odor components. Different compositions of raw materials such as lamb leg meat, lamb ribs, and lamb bones will alter the release characteristics of volatile substances during cooking, thus creating different odor profiles.

[0067] The W2S and W2W response values ​​of Comparative Example 4 were significantly higher than those of Example 2, indicating a significant difference in the volatile odor profiles formed by the two treatments. Therefore, Example 2 did not simply reduce the response of all volatile odor substances, but rather readjusted the volatile odor composition of the sample to form an odor profile that matched a higher aroma acceptability.

[0068] Further comparison of Examples 1 and 2 shows that the response values ​​of W1W, W2S, and W2W in Example 2 are improved, while the sensor responses of W1C, W5C, and W1S show little change. This indicates that after the backfilling of sheep-derived diglyceride lipids, some volatile odor-related responses are restored or enhanced, and the odor profile does not show an overall weakening, but rather a selective adjustment.

[0069] Sensory evaluation results of the samples ( Figure 3 The results indicate that different raw material compositions and processing techniques all have a certain impact on the color, aroma, taste, texture, and overall acceptability of mutton soup. Compared with Comparative Example 2, the weighted comprehensive sensory score of Example 1 increased from 59.33 points to 77.00 points, with increases of 35.00, 14.33, 17.67, 10.00, and 6.67 points in color, aroma, taste, texture, and overall acceptability, respectively. Although Comparative Example 2 had a lower fat content, its overall color, taste, and aroma were relatively lower, indicating that simply using low-fat raw materials to reduce fat content does not guarantee good overall sensory quality.

[0070] Compared with Comparative Example 1, the weighted overall sensory score of Example 1 increased from 72.08 to 77.00. Specifically, the scores for color, taste, texture, and overall acceptability increased by 11.67, 2.67, 12.08, and 6.67 points, respectively, while the aroma score decreased by 4.67 points. The results indicate that while some aroma characteristics changed after the cooling and skimming treatment, the taste, texture, and overall acceptability remained at a good level, resulting in improved overall sensory performance. This demonstrates that the process can effectively reduce fat content while maintaining good sensory quality.

[0071] Compared with Comparative Example 3, the weighted overall sensory score of Example 1 increased from 68.83 to 77.00, with improvements in color, texture, and overall acceptability of 15.00, 14.58, and 11.67 points respectively. Aroma and taste scores also improved. The results indicate that the composition and ratio of lamb leg meat and lamb ribs affect the overall sensory performance of the product. Under the conditions of this experiment, the 1:1 blend exhibited better overall sensory characteristics.

[0072] Further comparison of Comparative Example 4 and Example 2 showed that Example 2 achieved color, aroma, taste, texture, and overall acceptability scores of 89.17, 88.67, 90.67, 89.17, and 85.00, respectively, with a weighted comprehensive sensory score of 89.00. All five indicators were at a high level. Combined with the DAG composition and electronic nose analysis results, it is evident that under the DAG preparation and backfilling conditions used in Example 2, the product exhibits good overall color, flavor, and texture, providing a technical basis for further lipid structure optimization.

[0073] The experiment also investigated the fat content, color, and flavor of mutton soup prepared by combining lamb leg meat with other lamb parts. The results showed that when lamb belly meat and lamb leg meat were combined, the lamb belly meat had a high fat content, resulting in a high fat content in the mutton soup, which did not meet the low-fat requirements specified in the national standard GB 28050-2011. Although a low-fat mutton soup could be prepared at a very low ratio by reducing the proportion of lamb belly meat, the color and aroma of the final product were significantly different from those in Example 1.

[0074] The combination of lamb leg meat and lamb trotters also resulted in a fat content that did not meet the national standard for low-fat lamb. While combining lamb leg bones, lamb spine, and other lower-fat lamb cuts with lamb leg meat in a certain ratio could achieve a low-fat lamb soup with a color similar to that in Example 1, the flavor of the resulting soup was significantly inferior, ultimately leading to a low overall sensory score of less than 75 points. This is likely because different lamb cuts have different fat contents and tissue compositions, and their combination methods simultaneously affect the aroma, taste, texture, and overall acceptability of the lamb soup. Extensive experimentation revealed that only by combining lamb leg meat and lamb ribs in a specific ratio, combined with a cooling and skimming process to remove solidified fat, can a low-fat lamb soup be obtained while maintaining its flavor and color, thus increasing its acceptability. Furthermore, enzymatically hydrolyzing the cooled and skimmed oil and then refilling it into the mutton soup can further enhance the flavor and color of the mutton soup, increasing its acceptability. Under the DAG preparation and refilling conditions used in Example 2, the final sensory score of the mutton soup can reach 89 points.

[0075] In summary, this invention can reduce the fat content of the product while maintaining or improving the overall sensory quality of mutton soup.

[0076] The embodiments provided above are not intended to limit the scope of the invention, nor are the described steps intended to limit the order of execution. Any obvious modifications made to the invention by those skilled in the art based on existing common knowledge also fall within the scope of protection defined by the claims.

Claims

1. A method for preparing a low-fat mutton soup, characterized in that, Includes the following steps: (1) Raw material screening and pretreatment: Remove the excess fat visible on the surface of the mutton, and mix the mutton leg meat and mutton ribs in a mass ratio of 1:0.5 to 1:2 and cut them into pieces; (2) Cooking the raw materials: Add the diced lamb leg meat and lamb ribs from step (1) to water and cook at high temperature. After cooking, drain the lamb meat and the broth. (3) Cooling and skimming: Cool the raw broth obtained in step (2) to 30-35°C and let it stand to allow the mutton fat to separate and solidify; remove the solidified fat from the surface of the broth to obtain defatted raw broth. (4) Preparation of auxiliary ingredients: Add lamb bones, ginger, angelica, cinnamon, galangal, cardamom and fennel to water and cook to obtain auxiliary ingredient broth; (5) Mixing the broth: Mix the defatted raw material broth obtained in step (3) with the auxiliary material broth obtained in step (4), add salt and MSG to obtain the seasoned broth; (6) Filling, sealing and sterilization: The cooked mutton obtained in step (2) and the seasoning broth obtained in step (5) are filled, sealed and sterilized to obtain low-fat mutton soup.

2. The preparation method according to claim 1, characterized in that, In step (2), the mass ratio of the mixture of diced lamb leg meat and lamb ribs to water is 1:2~3, and the high-temperature cooking is carried out at 90~100℃ for 10~30 minutes.

3. The preparation method according to claim 1, characterized in that, In step (4), the mass ratio of lamb bone to water is 1:9~11, and the mass ratio of lamb bone to ginger, angelica, cinnamon, galangal, cardamom and fennel is 99~101:

1.

4. The preparation method according to claim 1, characterized in that, In step (5), the mass ratio of the defatted raw material broth to the auxiliary material broth is 1:1, the mass of added edible salt accounts for 5-6‰ of the total mass of the mixed broth, and the mass ratio of edible salt to monosodium glutamate is 1.9-2.1:

1.

5. The preparation method according to claim 1, characterized in that, Step (3) after removing solidified fat also includes the step of backfilling sheep-derived diglyceride lipids into the obtained defatted raw material broth. The sheep-derived diglyceride lipids are sheep-derived lipids rich in diglycerides prepared by enzymatic reaction using sheep fat as raw material.

6. The preparation method according to claim 5, characterized in that, The amount of sheep-derived diglyceride lipids added is 0.18~0.22 g / 100g in mass ratio to the defatted raw material broth.

7. The preparation method according to claim 5, characterized in that, The specific preparation steps for the sheep-derived diglyceride lipid are as follows: S1. Refining mutton fat: After melting mutton fat and removing impurities, refined mutton fat is obtained through degumming, decolorization and deodorization. S2. Preparation of mixed fatty acids: The refined mutton fat obtained in step S1 is saponified and hydrolyzed, and the saponified product is then acidified to obtain mixed fatty acids. S3. Preparation of diglycerides: Using glycerol and the mixed fatty acids from step S2 as substrates, Novozyme 435 as lipase, and the mixed fatty acids and glycerol obtained in step S2 as substrates, an enzymatic reaction was carried out. The enzyme was separated by centrifugation to obtain sheep-derived diglyceride lipids.

8. The preparation method according to claim 7, characterized in that, In step S3, the mass ratio of mixed fatty acids to glycerol in the substrate is 1:0.5 to 1:1.5, the added Novozyme 435 accounts for 1.5 to 4% of the mass of sheep fat, the enzymatic hydrolysis temperature is 50 to 65°C, the enzymatic hydrolysis time is 6 to 12 hours, and the enzyme activity of Novozyme 435 is ≥9000 PLU / g.

9. The preparation method according to claim 5, characterized in that, The backfilled sheep-derived diglyceride lipids are obtained by emulsifying the sheep-derived diglyceride lipids and then adding them to the low-fat mutton soup base. The emulsification process is carried out at a speed of 5000-10000 rpm for 5-15 minutes.

10. The low-fat mutton soup product prepared by the preparation method according to any one of claims 1 to 9.

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