Cat phagostimulant, preparation method thereof and pet food containing cat phagostimulant

Abstract

The invention discloses a cat phagostimulant, a preparation method thereof and pet food containing the cat phagostimulant. The cat phagostimulant comprises enzymolysis tallow, chicken liver protein enzymatic hydrolysate, xylose and a product of Maillard reaction of cysteine. The lipolysis degree of the enzymolysis tallow is 50-58%; the content of the enzymolysis tallow is 0.5-2.5% of the mass of the chicken liver protein enzymatic hydrolysate; the content of the xylose is 5-7% of the mass of the chicken liver protein enzymatic hydrolysate; the mass of the cysteine is 1%-2% of that of the chicken liver protein enzymatic hydrolysate. According to the cat phagostimulant, the content of characteristic flavor precursor substances is increased through precise enzymolysis of tallow, the chicken liver protein controllable Maillard reaction is cooperated, and a thermal reaction product with multi-layer meat flavor fragrance is directionally constructed, so that the cat phagostimulant with three-dimensional beef flavor and full and harmonious meat fragrance is prepared.

Description

Technical Field

[0001] This invention relates to the field of pet food chemistry technology, specifically to a cat palatability enhancer, its preparation method, and pet food containing the enhancer. Background Technology

[0002] In recent years, with the rapid development of the pet economy, cat food, as an important part of the pet food market, has seen its flavor and palatability become core concerns for both consumers and manufacturers. Palatability is a crucial indicator of cat food quality, influenced by factors such as taste, aroma, texture, and mouthfeel. Cats have a highly developed olfactory system, which can compensate for their relatively small number of taste buds through scent perception. Therefore, aroma plays a key role in a cat's eating decisions. Compared to plant-based ingredients, animal protein, amino acids, and fats are more effective at stimulating a cat's appetite. Enhancing the aroma richness of cat food, especially by mimicking meat flavors, is an important way to improve its palatability.

[0003] The Maillard reaction, a key pathway for food flavor formation, generates volatile substances such as aldehydes and heterocyclic compounds through the thermal reaction of amino acids and reducing sugars, mimicking the aroma of cooked meat. However, the thermal reaction products (MRPs) of single amino acids or sugars are limited in flavor complexity, failing to satisfy pets' preference for multi-layered meat aromas. The generation of key flavor precursors such as lipid degradation and its derivatives can significantly enhance the aroma characteristics of thermal reactions through synergistic effects, which is of great significance for the preparation of thermally reacted meat flavorings.

[0004] With the sustainable development of animal husbandry, chicken liver is one of the main by-products of slaughtering and processing, and also a high-quality food protein source (with a protein content of over 20%). Some researchers utilize its unique flavor to enhance the appeal of pet food. For cats and dogs, chicken liver is a very strong palatability enhancer. For picky eaters, those with poor appetites, or pets recovering from illness, adding a small amount of chicken liver to their food can effectively stimulate their appetite and ensure nutritional intake.

[0005] Existing research involves directly adding or spraying fat into cat food. In pet food processing, oil is typically sprayed onto the pellets after pelleting to achieve nutritional targets, but this approach has limitations in terms of flavor. However, current technologies for the synergistic regulation of characteristic flavors in beef through enzymatic lipid hydrolysis and Maillard reactions are still very limited, especially in the pet food industry where their practical application is yet to be seen. Summary of the Invention

[0006] Due to the aforementioned deficiencies in the existing technology, the present invention provides a cat palatability enhancer, its preparation method, and pet food containing the enhancer. By precisely enzymatically hydrolyzing beef tallow, the content of characteristic flavor precursor substances is increased, and the controllable Maillard reaction of chicken liver protein is synergistically used to construct multi-layered meat aroma thermal reaction products to obtain a cat palatability enhancer with a three-dimensional beef flavor and a full and harmonious meat aroma.

[0007] To achieve the above objectives, in a first aspect, the present invention provides a cat palatability enhancer comprising the product of a Maillard reaction of enzymatically hydrolyzed beef tallow, chicken liver protein hydrolysate, xylose, and cysteine.

[0008] The degree of lipolysis of the enzymatically hydrolyzed beef tallow is 50-58%.

[0009] The content of the enzymatically hydrolyzed beef tallow is 0.5-2.5% of the mass of the chicken liver protein hydrolysate; the content of xylose is 5-7% of the mass of the chicken liver protein hydrolysate; and the content of cysteine ​​is 1%-2% of the chicken liver protein hydrolysate.

[0010] The above technical solution increases the content of fatty acid derivatives in beef tallow by enzymatic hydrolysis of beef tallow with a specific degree of lipolysis, and synergizes with the controllable Maillard reaction of chicken liver protein hydrolysate to enhance the characteristic flavor of hot-reacting beef in cat palatability enhancers and improve the palatability of pet food.

[0011] In one embodiment, the degree of lipolysis of the enzymatically hydrolyzed beef tallow is 54-55%. The addition of beef tallow with a lipolysis degree of 54-55% significantly increases the content of characteristic flavor compounds in the cat palatability enhancer, such as 2-furfuryl mercaptan at 44.23-88.92 μg / kg, 2,5-dimethylpyrazine at 23.81-65.23 μg / kg, and 2-n-pentylfuran at 148.47-189.23 μg / kg.

[0012] In one embodiment, the key precursors in the enzymatically hydrolyzed beef tallow are oleic acid and linoleic acid from fatty acids, and (E,E)-2,4-nonadienal, (E)-2-decenal, and (E)-2-octenal from fatty acid derivatives, wherein aldehyde volatile flavor precursors account for 70.5% of the total precursors. The total amount of key flavor precursors is increased by 65-70% compared to the unhydrolyzed beef tallow group.

[0013] Secondly, the present invention provides a method for preparing a cat palatability attractant, comprising the steps of:

[0014] S1. Take refined beef tallow, add phosphate buffer solution and mix well to obtain a beef tallow mixture solution; add lipase to the beef tallow mixture solution for enzymatic hydrolysis, and stop the enzymatic hydrolysis and separate when the degree of lipolysis is 50~58% to obtain enzymatically hydrolyzed beef tallow.

[0015] After homogenizing the chicken liver, add alkaline protease for enzymatic hydrolysis and separate to obtain chicken liver protease hydrolysate;

[0016] S2. The chicken liver protein hydrolysate obtained in S1, enzymatically hydrolyzed beef tallow, xylose, and cysteine ​​are mixed. The mass of the enzymatically hydrolyzed beef tallow is 0.5-2.5% of the chicken liver protein hydrolysate; the mass of xylose is 5-7% of the chicken liver protein hydrolysate; and the mass of cysteine ​​is 1%-2% of the chicken liver protein hydrolysate. The reaction is heated until the ultraviolet absorbance of the product reaches 3.75-3.85 at 294 nm and 0.3-0.4 at 420 nm, thus preparing a cat palatability enhancer rich in the characteristic flavor of heat-reacted beef.

[0017] The above preparation method establishes a comprehensive monitoring system based on the ultraviolet absorbance of the product, with 294nm and 420nm absorbance as the core, combined with sensory evaluation and target characteristic flavor substance analysis. This system effectively determines the endpoint of the Maillard reaction and enables better quantitative control of the Maillard reaction products, resulting in a cat attractant rich in the characteristic flavor of heat-reacted beef.

[0018] In one embodiment, the concentration of beef tallow in the beef tallow mixture in step S1 is 30-66% w / w; the enzymatic hydrolysis process involves adding 200-400 U / g beef tallow lipase for 3-6 hours.

[0019] In one embodiment, the enzymatic hydrolysis process in step S2 involves adding 0.3~0.5 U / g chicken liver protein alkaline protease and hydrolyzing for 4~7 h.

[0020] Thirdly, the present invention provides a cat attractant prepared by the preparation method described above.

[0021] Fourthly, the present invention provides a cat food in which the surface of a basic cat food is coated with a cat palatability enhancer as described above.

[0022] Finally, the present invention provides a pet food, including natural pet food, and also including the cat palatability enhancer described above.

[0023] The above technical solution is only one feasible technical solution of the present invention. The scope of protection of the present invention is not limited thereto. Those skilled in the art can reasonably adjust the specific design according to actual needs.

[0024] The above invention has the following advantages or beneficial effects:

[0025] (1) This invention starts from the perspective of flavor enrichment and raw material health. It increases the content of beef fatty acid derivatives through lipase hydrolysis technology and chicken liver protein hydrolysate synergistic Maillard reaction to enhance the characteristic flavor of hot-reacting beef in cat palatability attractant and improve the palatability of pet food.

[0026] (2) This invention uses lipase to controllably hydrolyze beef tallow to release and degrade more free fatty acids, thereby increasing the content of characteristic flavor precursors. GC-MS analysis showed that the total amount of key flavor precursors was 65-70% higher than that of the unhydrolyzed beef tallow group.

[0027] (3) This invention is based on the technique of adding 50-58% lipolyzed beef tallow and a certain proportion of chicken liver protein hydrolysate to promote the formation of Maillard characteristic flavor compounds, which are then coated on the surface of cat food pellets or added to cat food to enhance the beef characteristic flavor and aroma of pet food. Palatability tests show that the cat food or pet food of this invention has a very good palatability effect, with an intake rate and first-choice rate both exceeding 52%. Attached Figure Description

[0028] The invention, its features and advantages will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings.

[0029] Figure 1 Radar graphs showing the sensory evaluation of cat palatability enhancers of Example 1 and Comparative Examples 1 to 4 of the present invention. Detailed Implementation

[0030] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0031] The reaction apparatus, reaction raw materials, and solvents involved in the following examples and embodiments are all commercially available.

[0032] The detection instruments and reagents used in the following examples are all commercially available, and the detection methods used are existing technologies that can be found online.

[0033] Among them, raw materials:

[0034] The refined beef tallow was purchased from the local market and made at home using a water-based oil-refining method.

[0035] Fresh chicken liver (74% water content) was purchased from Shanghai Xinyuan Co., Ltd.

[0036] Novozymes lipase Palatase 20000L (20000U / g) was purchased from Shanghai Zhentang Food Co., Ltd.

[0037] Detection method:

[0038] 1. Absorbance detection:

[0039] The absorbance is measured using ultraviolet-visible spectroscopy within a scanning range of 200–800 nm, with 1 nm intervals.

[0040] 2. Determination of degree of lipolysis:

[0041] Weigh 2.5 g of enzymatically hydrolyzed tallow and transfer it to a conical flask containing neutralized ethanol. Mix thoroughly and boil. Titrate with 0.1 mol / L sodium hydroxide standard solution, shaking vigorously during the titration. The titration endpoint is reached when the solution changes color and maintains that color for 15 seconds. The acid value (S) is calculated using the following formula:

[0042] S = 56.1 × V × C / m

[0043] In the formula: V is the volume of the sodium hydroxide standard solution used, in milliliters (mL); C is the accurate concentration of the sodium hydroxide standard solution used, in moles per liter (mol / L): 0.1 mol / L; m is the mass of the sample, in grams (g): 2.5 g.

[0044] Weigh 2 g of sample into a 250 mL flask and add 25 mL of 0.1 mol / L potassium hydroxide ethanol solution. Attach a condenser to the flask and reflux in a boiling water bath for 30–60 min until the fat in the flask is completely saponified (at this point, the liquid in the flask should be clear and free of oil droplets). Add 0.5 mL–1 mL of phenolphthalein indicator to the hot solution and titrate with 0.5 mol / L hydrochloric acid standard solution until the pink color of the indicator just disappears; this is the titration endpoint. Calculate the saponification value using the following formula. Following the above determination requirements, perform a blank test using 25.0 mL of potassium hydroxide-ethanol solution without adding the sample.

[0045] Saponification value = (C × (V1 - V2) × 56.1) / M

[0046] In the formula: C is the concentration of hydrochloric acid; V1 is the number of milliliters of hydrochloric acid consumed in the blank experiment; V2 is the number of milliliters of hydrochloric acid consumed in the fat experiment; M is the mass of beef tallow.

[0047] The degree of lipolysis (DH%) is mainly measured by two indicators: acid value and saponification value. The calculation method is shown in the following formula:

[0048] Degree of lipolysis (DH%) = Change in acid value before and after reaction / Saponification value

[0049] 3. Determination of free fatty acids (FFAs):

[0050] A 0.4 g tallow sample was dissolved in 10 mL of n-hexane. Free esters (FFAs) in the tallow sample were adsorbed using an aminopropyl column (500 mg / 6 mL Agilent Mega Bond Elut-NH2). Glyceryl esters were eluted with 2 mL of dichloromethane:isopropanol (2:1) solution, followed by FFA elution with 4 mL of 2% acetic acid-methyl tert-butyl ether solution. The separated FFA eluent was concentrated into an oily droplet by nitrogen blowing, and then methylated with 1 mL of sulfuric acid and methanol solution. After the reaction was complete and cooled to room temperature, 2 mL of n-hexane, 3 mL of water, and 1 mL of internal standard solution (3.6 mg / mL tridecylmethyl-methanol solution) were added and thoroughly mixed. After standing for 12 h, the supernatant was collected for further analysis. The FFA content was determined by GC-MS (gas chromatography-mass spectrometry). A full-scan method was used, with an electron ionization energy of 70 eV and a mass range of 30-450 m / z. The ion source temperature was 230℃. The column oven temperature was held at 40℃ for 2 min, increased to 120℃ at a rate of 10℃ / min, held for 3 min, and then increased to 230℃ at a rate of 2℃ / min, held for 15 min.

[0051] 4. Determination of flavor precursor content in beef tallow:

[0052] Accurately weigh 5 g of tallow sample and add it to a 15 mL extraction flask. Then add 5 μL of internal standard o-dichlorobenzene. Perform headspace extraction for 40 min using a well-aged extraction fiber tip (50 / 30 μm fiber tip: DVB / CAR / PDMS), maintaining the extraction temperature at 50 °C. Desorb from the extraction fiber tip for 10 min at 250 °C. Use an HP-NNOWAX (60 m × 0.25 mm × 0.25 m) column with N2 as the carrier gas. The injection port temperature is 250 °C, the injection volume is 1 μL, and the flow rate is 1.0 mL / min. The temperature program is as follows: first, hold at 40 °C for 3 min, then increase to 60 °C at 2 °C / min, then increase to 180 °C at 4 °C / min, and finally increase to 230 °C at 2 °C / min and hold for 15 min.

[0053] 5. Browning intensity determination:

[0054] Dilute the cat attractant 10 times with deionized water to form a solution. Take 3 mL of the sample and add it to a quartz dish (12.5×12.5×45 mm) that is transparent on both sides. Measure the absorbance of the sample at a wavelength of 420 nm using a UV-Vis spectrophotometer. The degree of browning of the sample is represented by A420.

[0055] 6. Sensory evaluation measurement:

[0056] A sensory evaluation team of 12 individuals (4 men and 4 women, aged 21-26) with food science backgrounds was selected. Team members underwent screening and training before the sensory evaluation, and thoroughly discussed the aroma attributes of the samples until a consensus on evaluation criteria was reached. The team members reached a consensus on the sensory descriptors discussed, using eight descriptors in the quantitative descriptive sensory analysis. These descriptors and their corresponding odor descriptions were "off-flavor," "cheesy aroma," "fatty aroma," "mushroom aroma," "beef aroma," "roasted aroma," "salty aroma," and "soy sauce aroma," and evaluation criteria for descriptive sensory evaluation were established. During the evaluation process, a nine-point scale was used to evaluate the intensity of the descriptors from "0" to "8," with a few minutes' interval between each pair of samples for sensory recovery. Each sample was repeated three times.

[0057] 7. Determination of flavor compounds in palatability enhancers:

[0058] 40 g of the attractant sample was accurately weighed and dissolved in 80 mL of dichloromethane. 400 μL of the internal standard o-dichlorobenzene was added to the dichloromethane for extraction three times at room temperature. The extract was then filtered to obtain the organic phase extract. The organic phase extract was then concentrated to 200 mL using a rotary evaporator. The concentrate was then subjected to high-vacuum distillation using solvent-assisted flavor evaporation (SAFE) technology to separate volatiles from non-volatiles. Extraction was performed at 40 °C. The extract was dehydrated with anhydrous sodium sulfate for 12 h, filtered, and concentrated by rotary evaporation to approximately 10 mL. This was then reduced to 1 mL by nitrogen blowing and stored at -20 °C for GC-MS analysis.

[0059] Accurately weigh 3g of the attractant sample and add it to a 15 mL extraction flask. Then add 10 μL of the internal standard o-dichlorobenzene. Qualitative analysis is performed using an HP-NNOWAX (60m × 0.25mm × 0.25m) column with N2 as the carrier gas, an injection port temperature of 250℃, an injection volume of 1 μL, and a flow rate of 1.0 mL / min. First, maintain the temperature at 40℃ for 3 min, then increase the temperature to 80℃ at 5℃ / min, then to 120℃ at 4℃ / min, and finally to 230℃ at 5℃ / min, holding for 10 min.

[0060] 8. Palatability test:

[0061] Cat food was prepared by spraying palatability enhancers onto basic feed and labeled as BCF0, BCF1, BCF2, and BCF3, with CF0 serving as a blank control. Twelve adult cats aged 1-3 years were selected for a palatability comparison test. Under normal healthy conditions, each cat was housed in a clean room at a temperature of (24±2)℃. The internationally recognized palatability comparison test method, the "double-basin method," was used. The test lasted for two days, with cats fed once a day at a fixed 18-hour interval. On the second day, the positions of the two basins were exchanged, and each cat was kept individually in a pet cage with free access to water. Each sample was accurately weighed to 100 g, and the first choice (the first bite eaten by the experimental cat) and the remaining amount of each sample were carefully recorded. The intake ratio of the sample was calculated by dividing the consumed grams by the provided grams.

[0062] Example 1:

[0063] The preparation of a cat palatability enhancer rich in the characteristic flavor of heat-reacted beef involves the following steps:

[0064] Take 100 g of refined beef tallow and mix it thoroughly with 100 g of water. Treat the mixture at 90℃ for 15 min, cool it, adjust the pH to 7.0, add 1.5 g of lipase to the solution, mix well, and then perform enzymatic hydrolysis at 60℃ for 5 h. After the reaction is complete, place the mixture in a boiling water bath for 20 min to inactivate the enzyme, centrifuge the supernatant, and obtain the enzymatically hydrolyzed beef tallow.

[0065] Weigh 100 g of chicken liver and inactivate the enzyme at 95℃ for 10 min. After enzyme inactivation, cool the liver and adjust the pH to 5.3. Add 0.192 g of papain (enzyme activity 80 U / g) and stir well. Set the temperature for enzymatic hydrolysis at 60℃ for 6 h. After hydrolysis, directly raise the temperature to 90℃ and time for 15 min to inactivate the enzyme. Cool to room temperature to obtain chicken liver enzymatic hydrolysate.

[0066] Weigh 1 g of enzymatically hydrolyzed tallow, 6 g of xylose, and 1.5 g of cysteine ​​into 100 g of chicken liver hydrolysate, dissolve and mix thoroughly, then pour into a Maillard reaction flask. Incubate in an oil bath at 105°C for 1 hour. Take 1 mL of the sample, dilute it tenfold with deionized water, mix well, centrifuge, and collect the supernatant. Transfer 1 mL of the solution to a quartz dish and monitor the reaction progress using a UV spectrophotometer at wavelengths of 294 nm and 420 nm. The reaction is considered complete when the absorbance values ​​reach 3.801 and 0.363, respectively. The absorbance at 294 nm corresponds to the formation of intermediate products (such as flavor precursors) during the reaction, while 420 nm is the most effective quantitative indicator of browning degree. Add maltodextrin, 0.62 g of sucrose fatty acid ester, 0.21 g of monosodium glutamate, 0.02 g of I+G, 0.33 g of sodium dehydrohexanoate and 0.17 g of potassium sorbate, mix and dissolve, and adjust the pH to 4 to obtain an appetite stimulant mixture.

[0067] 16.67 g of chicken fat was weighed at 45℃ and coated onto the surface of basic odorless cat food. Then, 40 g of palatability enhancer was sprayed evenly onto the surface of 200 g of basic odorless cat food and mixed thoroughly to obtain a cat food sample. Cat food sprayed with a commercially available similar palatability enhancer served as a blank control group.

[0068] Comparative Example 1:

[0069] The implementation process is similar to that of Example 1, except that the tallow is not enzymatically hydrolyzed. The reaction is considered complete when the absorbance values ​​at wavelengths of 294 nm and 420 nm reach 3.711 and 0.402, respectively.

[0070] Comparative Example 2:

[0071] The implementation process was similar to that of Example 1, except that the enzymatic hydrolysis time of beef tallow was 1 hour. The reaction was considered complete when the absorbance values ​​at wavelengths of 294 nm and 420 nm reached 3.583 and 0.251, respectively.

[0072] Comparative Example 3:

[0073] The implementation process was similar to that of Example 1, except that the enzymatic hydrolysis time of beef tallow was 4 hours. The reaction was considered complete when the absorbance values ​​at wavelengths of 294 nm and 420 nm reached 3.620 and 0.277, respectively.

[0074] Comparative Example 4:

[0075] The implementation process was similar to that of Example 1, except that the enzymatic hydrolysis time for tallow was 8 hours. The reaction was considered complete when the absorbance values ​​at wavelengths of 294 nm and 420 nm reached 3.911 and 0.411, respectively.

[0076] The degree of lipolysis and free fatty acid content of beef tallow in the cat palatability attractants of Examples 1 and Comparative Examples 1, 2, 3, and 4 are shown in Table 1. The content of characteristic flavor precursors of beef tallow in the palatability attractants is shown in Table 2. The degree of browning of the palatability attractants is shown in Table 3. The content of characteristic flavor substances in the palatability attractants is shown in Table 4. The sensory evaluation of the palatability attractants is as follows: Figure 1 As shown in Table 5, the palatability results of the palatability enhancers are presented.

[0077] Table 1: Degree of lipolysis and free fatty acid content of beef tallow in palatability enhancers

[0078]

[0079] Table 2: Content of flavor precursors of beef tallow in palatability enhancers

[0080]

[0081] Table 3: Browning degree of palatability enhancers

[0082]

[0083] Table 4: Content of characteristic flavor substances in palatability enhancers

[0084]

[0085] Table 5: Palatability results of palatability enhancers

[0086]

[0087] Note: Examples 1, 2, 3, and 4 were all subjected to palatability tests compared to cat food sprayed with similar commercially available palatability enhancers.

[0088] As can be seen from Examples 1 and Comparative Examples 1, 2, 3, and 4, the degree of lipolysis of beef tallow significantly affects the formation of characteristic compounds in the thermal reaction products, thus influencing the flavor characteristics of the palatability enhancer. Referring to Tables 1 and 2, Example 1 showed the highest proportion of saturated fatty acids, significantly higher than Comparative Example 1 (8.172±0.117c), Comparative Example 2 (10.125±1.103b), Comparative Example 3 (11.549±0.416b), and Comparative Example 4 (15.322±0.264b). Comparative Example 1 showed the lowest unsaturated fatty acid content, significantly decreasing by 36.23% (Comparative Example 2), 23.82% (Comparative Example 3), 55.63% (Comparative Example 4), and 46.79% (Example 1), respectively. GC-MS analysis showed that fatty acid-derived aldehydes, as the main flavor precursors, increased significantly by 68% in Example 1, with a total amount of 7422.61 μg / kg ± 0.43a. These aldehydes participated more extensively in the Maillard reaction, thus influencing the formation of the characteristic meat flavor of the thermal reaction products. Figure 1The results in Tables 3 and 4 show that Comparative Example 1 had the lowest overall taste score. In contrast, Example 1 enhanced the overall fatty, mushroom, beef, and roasted aromas of the product, while reducing off-flavors. Example 1 had the highest beef aroma score. When the UV absorbance of the product reached 3.75–3.85 at 294 nm and 0.3–0.4 at 420 nm, the number and content of characteristic flavor compounds of the palatability enhancer also increased significantly, such as 2-furfuryl mercaptan at 82.31 μg / kg ± 1.10a, 2,5-dimethylpyrazine at 60.91 μg / kg ± 0.70a, and 2-n-pentylfuran at 429.03 μg / kg ± 0.28a. This indicates that Example 1 played a coordinating, complementary, and enriching role in enhancing the overall flavor of the thermally reacted product. Table 5 shows that the palatability improvement effects of Example 1 and Comparative Examples 1, 2, 3, and 4 on cats differed significantly. In the two-day feeding experiment, the experimental group showed significantly higher first-choice rate and intake rate than the control group (commercially available CF cat food, sprayed with a commercially available palatability enhancer without tallow). The intake rate of Example 1 group differed significantly from that of Comparative Examples 1, 2, 3, and 4 (p < 0.05). Regarding the first-choice rate, Example 1 group and Comparative Examples 1, 2, and 3 all reached over 60%, with Example 1 having the highest first-choice rate at 73.07%, followed by Comparative Example 3 (69.23%), Comparative Example 1 (63.33%), Comparative Example 2 (60.00%), and Comparative Example 4 (57.84%). In conclusion, the experimental cats showed significantly higher acceptance and preference for the palatability enhancer prepared in Example 1 in terms of aroma or flavor.

[0089] It is evident that, during the preparation of palatability enhancers, when the degree of lipolysis of beef tallow reaches the range of 50-58%, palatability enhancers with a 65-70% increase in the content of key precursor substances rich in beef characteristic flavor can be stably prepared under different treatment times.

[0090] Those skilled in the art should understand that variations can be implemented by combining existing technology with the above embodiments, which will not be elaborated here. Such variations do not affect the essence of the present invention, and will not be elaborated here either.

[0091] The preferred embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and the devices and structures not described in detail should be understood as being implemented in a conventional manner in the art. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention using the methods and techniques disclosed above, or modify them into equivalent embodiments with equivalent changes, without departing from the scope of the present invention. This does not affect the essential content of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the present invention's technical solutions still fall within the protection scope of the present invention.

Claims

1. A cat palatability attractant, characterized in that: Rich in the characteristic flavor of heat-reacted beef; Products of Maillard reaction involving enzymatic hydrolysis of beef tallow, chicken liver protein hydrolysate, xylose, and cysteine; The degree of lipolysis of the enzymatically hydrolyzed beef tallow is 50-58%. The content of the enzymatically hydrolyzed beef tallow is 0.5-2.5% of the mass of the chicken liver protein hydrolysate; the content of xylose is 5-7% of the mass of the chicken liver protein hydrolysate; and the content of cysteine ​​is 1%-2% of the chicken liver protein hydrolysate.

2. The cat attractant according to claim 1, characterized in that, The degree of lipolysis of the enzymatically hydrolyzed beef tallow is 54-55%.

3. The cat attractant according to claim 2, characterized in that, The cat attractant contains 44.23–88.92 μg / kg of 2-furfuryl mercaptan, a characteristic aroma compound of beef; 23.81–65.23 μg / kg of 2,5-dimethylpyrazine; and 148.47–189.23 μg / kg of 2-n-pentylfuran.

4. The cat attractant according to claim 1, characterized in that, The key precursors in the enzymatically hydrolyzed beef tallow are oleic acid and linoleic acid in fatty acids, as well as (E,E)-2,4-nonadienal, (E)-2-decenal and (E)-2-octenal in fatty acid derivatives, of which volatile aldehyde flavor precursors account for 70.5% of the total precursors.

5. A method for preparing a cat palatability attractant, characterized in that, Including the following steps: S1. Take refined beef tallow, add phosphate buffer solution and mix well to obtain a beef tallow mixture solution; add lipase to the beef tallow mixture solution for enzymatic hydrolysis, and stop the enzymatic hydrolysis and separate when the degree of lipolysis is 50~58% to obtain enzymatically hydrolyzed beef tallow. After homogenizing the chicken liver, add alkaline protease for enzymatic hydrolysis and separate to obtain chicken liver protease hydrolysate; S2. The chicken liver protein hydrolysate obtained in S1, enzymatically hydrolyzed beef tallow, xylose, and cysteine ​​are mixed. The mass of the enzymatically hydrolyzed beef tallow is 0.5-2.5% of the chicken liver protein hydrolysate; the mass of xylose is 5-7% of the chicken liver protein hydrolysate; and the mass of cysteine ​​is 1%-2% of the chicken liver protein hydrolysate. The reaction is heated until the ultraviolet absorbance of the product reaches 3.75-3.85 at 294 nm and 0.3-0.4 at 420 nm, thus preparing a cat palatability enhancer rich in the characteristic flavor of heat-reacted beef.

6. The method for preparing a cat attractant according to claim 5, characterized in that, In step S1, the concentration of beef tallow in the beef tallow mixture is 30-66% w / w; the enzymatic hydrolysis process involves adding 200-400 U / g beef tallow lipase and hydrolyzing for 3-6 hours.

7. The method for preparing a cat attractant according to claim 5, characterized in that, In step S2, the enzymatic hydrolysis process involves adding 0.3-0.5 U / g of chicken liver protein with alkaline protease and hydrolyzing for 4-7 hours.

8. A cat attractant, characterized in that, It is prepared by the preparation method according to any one of claims 5 to 7.

9. A type of cat food, characterized in that, The surface of the basic cat food is covered with a cat palatability enhancer as described in any one of claims 1 to 4 or as described in claim 8.

10. A pet food, comprising natural pet food, characterized in that, It also includes the cat attractant as described in any one of claims 1 to 4 or the cat attractant as described in claim 8.

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