Compound feed additive for improving flavor of eggs, preparation process and compound feed

Abstract

The invention provides a compound feed additive capable of improving the flavor of eggs, a preparation technology and a compound feed, and relates to the technical field of feed preparation.Main components in shaddock peel are analyzed, the main components influencing the flavor of the eggs are screened out, and chemical components and shaddock peel powder are adopted to prepare the compound feed additive. The grapefruit flavor extract (active ingredients such as limonene, polyphenols and the like) prepared on the basis of the grapefruit peel powder. The preparation method comprises the following steps: compounding the raw materials in parts by weight: 20-40 parts of linalool, 5-10 parts of linalyl acetate, 2-4 parts of limonene, 1-2 parts of vanillyl alcohol, 0.7-1.4 parts of geranyl acetate, 5-10 parts of myrcene, 80 parts of pomelo peel powder, 150 parts of a carrier and 70 parts of a pomelo flavor extract; the total addition amount of the shaddock peel powder in the basal feed is reduced from 2% to 0.1%, a good flavor improvement effect can be maintained, and dependence on shaddock peel raw materials is greatly reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of feed preparation, in particular to a compound feed additive for improving the flavor of eggs, a preparation process and a compound feed. BACKGROUND

[0002] Eggs are indispensable nutritional food materials in people's daily life, and raw eggs themselves have an egg odor, which is mainly derived from nitrogen-containing heterocyclic compounds such as pyridine, pyrazine, pyrrole and thiazole, and volatile flavor substances such as aldehydes and indane. Cooked eggs have a fragrance, and the fragrance of cooked eggs is mainly derived from volatile substances such as alky aromatic, nitrile and ketone generated by oxidation or degradation of fatty acids, amino acids, pigments, hydroxy acids (synthetic ene terpenes), monosaccharides and glycosides in eggs, especially aldehyde, ketone and alcohol small molecules generated by oxidation and decomposition of fatty acids, which play an important role in the flavor of eggs.

[0003] To improve the flavor of eggs, the principle of flavor substance deposition into eggs needs to be considered. The flavor of eggs is a mixture of a variety of flavor substances in different proportions and concentrations. These flavor substances mainly include volatile flavor substances, fatty acids, phospholipids, amino acids and small peptides.

[0004] Volatile flavor substances can be divided into eight categories, including aliphatic hydrocarbons, aldehydes, ketones, alcohols, aromatic compounds, furans, sulfides and terpenes. Among them, aliphatic hydrocarbons have the highest content and are almost universally present in all eggs, but have little effect on egg flavor. In contrast, aldehydes and aromatic compounds have a lower threshold, but play a major role in egg flavor. Nutritional ingredients in eggs, such as proteins and fatty acids, are also important factors affecting egg flavor. Sulfur and nitrogen elements in proteins are converted into hydrogen sulfide and ammonia gas under the action of bacteria, and these gases have a strong odor.

[0005] To improve the flavor of eggs, the composition of feed can be used to improve the flavor of eggs, and the preparation and pickling process of eggs can also be used to improve the flavor of eggs. The composition of laying hen diet directly affects the quality and flavor of eggs. For example, adding excessive fish meal or fish oil to the diet of laying hens, the oxidized trimethylamine in fish meal is oxidized to trimethylamine with fishy odor under the action of intestinal microorganisms in the chicken body, which is deposited in the egg and has an odor, resulting in moldy, not fresh, rancid and fishy eggs. In addition, the spoilage of unsaturated fatty acids in fish meal or fish oil is also a factor that leads to the decline of egg flavor.

[0006] It is found through research that there are a large amount of volatile active substances in grapefruit peel, such as limonene, polyphenols, etc. These substances mostly have antioxidant and anti-inflammatory components, and they exhibit significant effects in terms of antioxidant, antibacterial, and inhibition of pancreatic lipase. The flavor of eggs is affected by factors such as the flavor of raw materials, the health of laying hens, the immune ability, and the anti-oxidation ability. Therefore, we speculate that some components of grapefruit peel can be deposited in eggs, especially in egg yolks, and interact with egg yolk components to improve the flavor of eggs. Our previous research found that adding 2% grapefruit peel powder to the feed of laying hens can significantly improve the flavor of eggs. However, due to the large amount of addition, the limited source of grapefruit peel (currently, the amount of natural grapefruit peel is small and is affected by region and origin), it is difficult to meet the production demand. SUMMARY

[0007] The purpose of the embodiments of the present application is to provide a compound feed additive for improving the flavor of eggs, a preparation process, and a compound feed, so as to greatly reduce the addition amount of grapefruit peel powder in the feed of laying hens, and achieve a good effect of improving the flavor of eggs, and meet the production demand of large-scale commercialization.

[0008] In order to achieve the above-mentioned purpose, the embodiments of the present application are realized by the following ways:

[0009] The embodiments of the present application provide a compound feed additive for improving the flavor of eggs, which comprises the following substances in parts by weight: linalool 20-40 parts, linalyl acetate 5-10 parts, limonene 2-4 parts, vanillyl alcohol 1-2 parts, geranyl acetate 0.7-1.4 parts, myrcene 5-10 parts, grapefruit peel powder 80 parts, carrier 150 parts, and grapefruit flavor extract 70 parts.

[0010] Further, the carrier is 50 parts of an organic carrier and 100 parts of a functional carrier, the organic carrier is defatted rice bran, defatted bran, or a combination of the two, and the functional carrier is zeolite powder.

[0011] Further, the linalool is 20 parts, the linalyl acetate is 5 parts, the limonene is 2 parts, the vanillyl alcohol is 1 part, the geranyl acetate is 0.7 part, the myrcene is 5 parts, the grapefruit peel powder is 80 parts, the carrier is 150 parts, and the grapefruit flavor extract is 70 parts.

[0012] Further, the linalool is 40 parts, the linalyl acetate is 10 parts, the limonene is 4 parts, the vanillyl alcohol is 2 parts, the geranyl acetate is 1.4 parts, the myrcene is 10 parts, the grapefruit peel powder is 80 parts, the carrier is 150 parts, and the grapefruit flavor extract is 70 parts.

[0013] Further, the linalool is 30 parts, the linalyl acetate is 7.5 parts, the limonene is 3 parts, the vanillyl alcohol is 1.5 parts, the geranyl acetate is 1 part, the myrcene is 7.5 parts, the grapefruit peel powder is 80 parts, the carrier is 150 parts, and the grapefruit flavor extract is 70 parts.

[0014] Further, the grapefruit flavor extract is obtained by headspace solid phase microextraction of grapefruit peel powder, microencapsulation and carrier mixing.

[0015] The application further provides a preparation process of a compound feed additive for improving egg flavor, comprising: S1, selecting fresh grapefruit peel, washing, low-temperature drying, crushing, and screening through an 80-mesh screen to obtain grapefruit peel powder; S2, preparing grapefruit flavor extract from the grapefruit peel powder; S3, mixing linalool, linalyl acetate, limonene, vanillyl alcohol, geranyl acetate and myrcene in a proportion to obtain a flavor ingredient mixture; S4, spraying the flavor ingredient mixture in an atomized form to activated zeolite powder; S5, adding the zeolite powder adsorbed with the flavor ingredients, grapefruit peel powder and defatted rice bran into a double-cone mixer, and mixing at a low speed for 30 minutes under nitrogen protection; and S6, adding the prepared grapefruit flavor extract into the double-cone mixer, and continuing to mix at a low speed for 30 minutes to obtain the prepared compound feed additive for improving egg flavor.

[0016] Further, the grapefruit flavor extract is prepared in the following manner: S21, headspace solid phase microextraction of grapefruit peel powder to obtain grapefruit flavor extract liquid; S22, concentration and solvent recovery of the grapefruit flavor extract liquid to obtain grapefruit flavor concentrate; S23, microencapsulation of the grapefruit flavor concentrate to form microcapsules, wherein the microcapsule wall material is a 1:1 mixture of β-cyclodextrin and gum arabic; and S24, mixing the microcapsules with 80-mesh puffed corn powder after baking sterilization in a proportion of 9:1 to obtain uniformly mixed grapefruit flavor extract.

[0017] The application further provides a compound feed for improving egg flavor, which is prepared by adding the compound feed additive for improving egg flavor prepared by the preparation process to the base feed.

[0018] Further, the addition proportion of the compound feed additive is 0.1%-0.3%.

[0019] Beneficial effects:

[0020] 1. The scheme selects the main components affecting egg flavor from grapefruit peel, and prepares a compound feed additive for improving egg flavor by compounding the main components, grapefruit peel powder and grapefruit flavor extract (concentrated effective components such as limonene and polyphenols in grapefruit peel, prepared by microencapsulation and mixing with puffed corn powder) based on grapefruit peel powder. The total addition amount of grapefruit peel powder in the base feed is reduced from 2% to 0.1%, and a good flavor improvement effect can be maintained, the dependence on grapefruit peel raw materials is greatly reduced, and the production demand of large-scale commercialization can be met.

[0021] 2. The compound feed additive formula for improving the flavor of chicken eggs combines grapefruit peel extract with a variety of terpenes and esters (such as linalyl acetate and myrcene) to mask egg odor (such as pyridine and trimethylamine) through synergistic effects, while promoting the formation of aldehydes and ketones in cooked chicken eggs. Low-threshold components (such as aromatic compounds and aldehydes) directly dominate the flavor, and high-content aliphatic hydrocarbons serve as carriers without interfering with the overall flavor. When preparing grapefruit flavor extract, β-cyclodextrin and gum arabic (1:1 mixture) are used as wall materials to protect volatile substances (such as limonene) in the concentrated solution from oxidation and degradation, extend the action time, and ensure that the active ingredients are released slowly in the intestinal tract of laying hens and deposited in the egg yolk. Zeolite powder adsorbs odor-causing substances such as trimethylamine and hydrogen sulfide in the intestinal tract, and defatted rice bran provides a uniformly dispersed physical carrier to reduce the loss of active ingredients. Moreover, since grapefruit peel powder contains pectin and cellulose, it can form a multi-level "adsorption network" with zeolite powder and organic carriers (rich in cellulose) to further fix volatile components and reduce flavor loss: activated zeolite powder can strongly adsorb small molecular terpenes such as linalool and limonene due to its porous structure with pore diameters of 0.4-1.2 nm, achieving molecular-level locking; the gel network can wrap zeolite particles, and cellulose fibers can be inserted between zeolite particles to prevent zeolite agglomeration, fill its large pores (>2 nm) and gaps, and reduce the loss of aroma during processing and storage; and rice bran fibers cover the surface and adsorb non-polar molecules such as myrcene through hydrophobic interactions, forming an outer slow-release layer. The polyphenols in grapefruit peel can enhance the immune function of laying hens, reduce lipid peroxidation caused by oxidative stress, and reduce the generation of odor-causing substances (such as ammonia) in eggs. Zeolite powder can also adsorb harmful metabolites, improve the intestinal microecology, and indirectly enhance the flavor of chicken eggs.

[0022] 3. The compound scheme of natural flavor extraction (grapefruit flavor extract prepared based on grapefruit peel powder) + chemical components (such as linalool, linalyl acetate, limonene, vanillyl alcohol, geranyl acetate, myrcene, etc.) + natural grapefruit peel powder (grapefruit peel powder crushed to 80 mesh) can also improve the flavor of eggs well in the case of greatly reducing the amount of grapefruit peel powder (from 2% to about 0.1%). It has been verified by experiments that the improvement of egg flavor is in appearance (mainly egg yolk and egg white: compared with the control group, the color of the egg yolk of all the flavored groups is much brighter and brighter, showing golden yellow, which gives people a warm and appetite in vision, and the color of the egg white after cooking is whiter than the control group, which forms a contrast with the egg yolk and increases the visual appeal), aroma (the control group has a distinct egg smell, the egg smell of all the flavored groups is significantly reduced, and some flavored groups even have a slight or no obvious egg smell, and show a comfortable aroma, which enhances the layer of egg flavor), taste (compared with the control group, the egg yolk and egg white of the flavored group can have better taste, the egg yolk feels more delicate in the mouth, and the elasticity of the egg white is better), and taste (compared with the control group, the egg of the flavored group has a more delicious taste).

[0023] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the following preferred embodiments are specifically described as follows. DETAILED DESCRIPTION

[0024] It should be noted that the test methods in the following examples are conventional methods, and the test materials used in the following examples are commercially available. The features and performance of the present application are further described in detail below in combination with examples.

[0025] Example 1

[0026] A compound feed additive for improving the flavor of eggs comprises the following substances in parts by weight: linalool 20-40 parts, linalyl acetate 5-10 parts, limonene 2-4 parts, vanillyl alcohol 1-2 parts, geranyl acetate 0.7-1.4 parts, myrcene 5-10 parts, grapefruit peel powder 80 parts, carrier 150 parts, and grapefruit flavor extract 70 parts.

[0027] The grapefruit flavor extract is obtained by headspace solid-phase microextraction, concentration, microencapsulation, carrier mixing and other treatments of grapefruit peel powder, and the specific preparation process is described in detail below.

[0028] The carrier is 50 parts of an organic carrier and 100 parts of a functional carrier. The organic carrier is defatted rice bran, defatted bran or a combination of the two (for example, only defatted rice bran is used, or only defatted bran is used, or an equal amount of defatted rice bran and defatted bran is used). The functional carrier is zeolite powder.

[0029] The preparation process of the compound feed additive for improving the flavor of eggs is as follows:

[0030] S1: Fresh pomelo peel is selected, washed, dried at low temperature, and crushed to pass through an 80-mesh screen to obtain pomelo peel powder.

[0031] Here, the pomelo peel powder has two uses, which need to be allocated according to weight. One is 80 parts of pomelo peel powder needed for compounding, and the other is 120 parts of pomelo peel powder needed for preparing pomelo flavor extract.

[0032] S2: The pomelo peel powder is taken to prepare pomelo flavor extract.

[0033] Here, 120 parts of pomelo peel powder are taken, and the following preparation process is used to prepare pomelo flavor extract:

[0034] S21: Headspace solid phase microextraction is performed on the pomelo peel powder to obtain pomelo flavor extract.

[0035] Specifically, the pomelo peel powder is placed in a headspace bottle, preheated at 60°C for 10 minutes, a DVB / CAR / PDMS fiber head is inserted, and extraction is performed for 40 minutes. Here, 60°C can balance and activate volatile substances, and avoid damaging the structure of terpenes due to high temperature. Other similar parameters during the extraction process can also be used (for example, parameter settings within a range of 10%), which should not be considered as limiting the present application. Then, desorption is performed at a GC injection port at 250°C for 5 minutes, and volatile components are collected.

[0036] S22: The pomelo flavor extract is concentrated and solvent is recovered to obtain pomelo flavor concentrate.

[0037] After obtaining the pomelo flavor extract, the extract is transferred to a rotary evaporator, concentrated at 40°C under reduced pressure to 1 / 10 of the original volume, and the ethanol solvent is recovered. Low-temperature and reduced-pressure concentration prevents oxidation of heat-sensitive substances such as polyphenols and terpenes.

[0038] It should be noted that the pomelo flavor concentrate obtained here can be further compounded, but the present embodiment does not perform compounding in this process, which should not be considered as limiting.

[0039] S23: The pomelo flavor concentrate is subjected to microcapsule embedding treatment to form microcapsules, wherein the microcapsule wall material is a 1:1 mixture of β-cyclodextrin and gum arabic.

[0040] Here, the 1:1 mixture of β-cyclodextrin and gum arabic is selected as the wall material, which can reduce the loss of volatile substances by encapsulating limonene in the β-cyclodextrin hydrophobic cavity. Specifically, the grapefruit flavor concentrate is mixed with the wall material (a 1:1 mixture of β-cyclodextrin and gum arabic) at a mass ratio of 1:3, homogenized at 50°C for 30 minutes, and then spray dried (inlet temperature 160°C, outlet temperature 80°C) to complete the microencapsulation process.

[0041] S24: After baking and sterilization, the puffed corn flour with a particle size of 80 mesh is mixed with the microcapsules at a ratio of 9:1 to obtain a uniformly mixed grapefruit flavor extract.

[0042] The puffed corn flour with a particle size of 80 mesh (80-100 mesh) is selected as the carrier, baked at 120°C for 20 minutes for sterilization, cooled to room temperature, and then mixed with the microcapsules at a ratio of 1:9 to obtain a uniformly mixed grapefruit flavor extract. The mixing can be done in multiple stages, for example, the microcapsules and the carrier are mixed at a ratio of 1:3 in a V-type mixer at low speed for 20 minutes (e.g. 15 revolutions per minute), and the remaining carrier is added for secondary mixing at low speed for 30 minutes (e.g. 20 revolutions per minute) to ensure uniform mixing.

[0043] Thus, the preparation of grapefruit flavor extract can be completed, and about 70 parts of grapefruit peel powder can be obtained from 120 parts of grapefruit peel powder. In actual experiments, due to differences in grapefruit peel varieties (such as Shatian grapefruit, Wenden grapefruit, grapefruit, honey grapefruit, and western grapefruit, preferably grapefruit and western grapefruit, which have relatively high flavor component content) and flavor component extraction efficiency, the fluctuation will be larger (mainly caused by the type and quality of the seed coat), and if the ingredients are strictly formulated, the fluctuation range can reach 45-120, but by controlling the variety and quality of the grapefruit peel, the fluctuation range can be effectively reduced. In this embodiment, the empirical value of the grapefruit flavor extract from a certain variety (such as grapefruit) of grapefruit peel powder is taken as an example, and 70 parts are taken as an example, which should not be considered as a limitation of the present application. Of course, subsequent large-scale production requires strict quality control, and the specific type and quality of the grapefruit peel powder can produce a certain amount of grapefruit flavor extract, which will not greatly fluctuate the preparation quality of the compound feed additive for improving the flavor of eggs. If the grapefruit flavor extract obtained from a unit mass of grapefruit peel powder is less, more grapefruit peel powder can be consumed.

[0044] S3: Mix linalool, linalyl acetate, limonene, vanillin, geranyl acetate, and myrcene in proportion to obtain a flavor component mixture.

[0045] The basis for selecting the components in this embodiment is to analyze the main source of aroma in grapefruit peel (about 1-3% of the dry peel weight):

[0046] Limonene: 85-95% of the total amount of essential oil, dominant citrus fresh aroma.

[0047] β-Myrcene: grassy aroma.

[0048] α / β-Pinene: pine, resinous aroma.

[0049] γ-Terpinene: citrus herbal aroma.

[0050] Citral: including Geranial and Neral, strong lemon aroma.

[0051] Decanal, Octanal: fruity and fatty aroma.

[0052] Linalyl acetate: floral, lavender aroma.

[0053] Geranyl acetate: rose and fruity aroma.

[0054] Neryl acetate: sweet orange flower aroma.

[0055] Linalool: lily of the valley floral aroma.

[0056] Geraniol, Nerol: rose floral sweet aroma.

[0057] Nootkatone: grapefruit bitter and woody aroma.

[0058] After screening, linalool, linalyl acetate, limonene, geranyl acetate, and myrcene are mainly selected, and vanillin (with better antioxidant properties) is introduced.

[0059] Geranyl acetate and myrcene are generally stored in the dark and refrigerated (4°C), and need to be warmed to 25°C before use to reduce viscosity and ensure uniformity of the spray mixture. Then mix linalool (20-40 parts), linalyl acetate (5-10 parts), limonene (2-4 parts), vanillin (1-2 parts), geranyl acetate (0.7-1.4 parts), and myrcene (5-10 parts) in the ratio to obtain a flavor ingredient mixture. Of course, a small amount of natural antioxidant (such as vitamin E or rosemary extract) can also be added, the proportion does not exceed 0.015%.

[0060] S4: Spray the flavor ingredient mixture in the form of atomization to the activated zeolite powder.

[0061] The zeolite powder (passing 200 mesh sieve) needs to be activated before use, calcined at 400℃ for 2 hours (activation can open the pores of the zeolite powder, and improve the adsorption capacity), and stored in a sealed state after cooling. When used, the flavor ingredient mixture can be sprayed in the form of mist into the activated zeolite powder (75-100 parts), and in order to balance the absorption, it can also be sealed and aged (12-24 hours).

[0062] S5: The zeolite powder after adsorbing flavor ingredients, pomelo peel powder and defatted rice bran are added to a double-cone mixer, mixed at low speed for 30 minutes under nitrogen protection.

[0063] Specifically, the zeolite powder after adsorbing flavor ingredients, pomelo peel powder and defatted rice bran are added to a double-cone mixer, mixed at low speed (such as 20 revolutions per minute) for 30 minutes under nitrogen protection.

[0064] S6: The prepared pomelo flavor extract is added to the double-cone mixer, and low-speed mixing is continued for 30 minutes to obtain the prepared composite feed additive for improving egg flavor.

[0065] The prepared pomelo flavor extract (70 parts for example) is added to the double-cone mixer, and low-speed mixing (20 revolutions per minute) is continued for 30 minutes, and then sieving (such as 20 mesh sieve) is performed to remove lumps, to obtain the composite feed additive for improving egg flavor.

[0066] After obtaining the composite feed additive for improving egg flavor, it can be applied to the preparation of chicken feed. The prepared composite feed additive for improving egg flavor is added to the base feed, and the addition ratio can be 0.1%-0.3%.

[0067] Overall, about 200 parts of pomelo peel powder can be consumed to prepare 330-360 parts of composite feed additive for improving egg flavor. If added to the base feed at an addition ratio of 0.1%, the comprehensive consumption of pomelo peel powder is less than 0.1%, and if added at a ratio of 0.3%, the comprehensive consumption of pomelo peel powder is not more than 0.2%.

[0068] Example 2

[0069] A compound feed additive for improving the flavor of eggs, comprising the following components in parts by weight: linalool 20 parts, linalyl acetate 5 parts, limonene 2 parts, vanillyl alcohol 1 part, geranyl acetate 0.7 parts, myrcene 5 parts, pomelo peel powder 80 parts, carrier 150 parts (organic carrier 50 parts, selected from defatted rice bran, defatted bran or a combination of the two, the three types of organic carriers have little difference in the present solution; functional carrier 100 parts, selected from zeolite powder), pomelo flavor extract 70 parts. The compound feed additive for improving the flavor of eggs prepared according to the above formula is denoted as compound feed additive A; the compound feed additive A is added into the base feed in proportions of 0.1%, 0.2% and 0.3% respectively to obtain compound feed 1, compound feed 2 and compound feed 3.

[0070] Example 3

[0071] A compound feed additive for improving the flavor of eggs, comprising the following components in parts by weight: linalool 30 parts, linalyl acetate 7.5 parts, limonene 3 parts, vanillyl alcohol 1.5 parts, geranyl acetate 1 part, myrcene 7.5 parts, pomelo peel powder 80 parts, carrier 150 parts (organic carrier 50 parts, selected from defatted rice bran, defatted bran or a combination of the two, the three types of organic carriers have little difference in the present solution; functional carrier 100 parts, selected from zeolite powder), pomelo flavor extract 70 parts. The compound feed additive for improving the flavor of eggs prepared according to the above formula is denoted as compound feed additive B; the compound feed additive B is added into the base feed in proportions of 0.1%, 0.2% and 0.3% respectively to obtain compound feed 4, compound feed 5 and compound feed 6.

[0072] Example 4

[0073] A compound feed additive for improving the flavor of eggs, comprising the following components in parts by weight: linalool 40 parts, linalyl acetate 10 parts, limonene 4 parts, vanillyl alcohol 2 parts, geranyl acetate 1.4 parts, myrcene 10 parts, pomelo peel powder 80 parts, carrier 150 parts (organic carrier 50 parts, selected from defatted rice bran, defatted bran or a combination of the two, the three types of organic carriers have little difference in the present solution; functional carrier 100 parts, selected from zeolite powder), pomelo flavor extract 70 parts. The compound feed additive for improving the flavor of eggs prepared according to the above formula is denoted as compound feed additive C; the compound feed additive C is added into the base feed in proportions of 0.1%, 0.2% and 0.3% respectively to obtain compound feed 7, compound feed 8 and compound feed 9.

[0074] Based on the above examples, the present solution designs experiments:

[0075] Laying hen breeds: Select the same batch of laying hens with similar health status, 30 in each group, a total of 11 groups, respectively: Experimental group 1 (control group, fed with basic feed during the experimental period), experimental group 2 (fed with compound feed added with 2% pomelo peel powder during the experimental period), experimental group 3 (fed with compound feed 1 during the experimental period), experimental group 4 (fed with compound feed 2 during the experimental period), experimental group 5 (fed with compound feed 3 during the experimental period), experimental group 6 (fed with compound feed 4 during the experimental period), experimental group 7 (fed with compound feed 5 during the experimental period), experimental group 8 (fed with compound feed 6 during the experimental period), experimental group 9 (fed with compound feed 7 during the experimental period), experimental group 10 (fed with compound feed 8 during the experimental period), experimental group 11 (fed with compound feed 9 during the experimental period).

[0076] Feeding environment: Standardized chicken house, temperature (20-25℃), humidity (50-70%), light cycle (16 hours light / 8 hours dark).

[0077] Adaptation period: Pre-feed basic feed for 2 weeks to eliminate the influence of previous feed. Experimental period: Each group was fed with corresponding feed for 6 weeks, and the daily feed intake, egg production rate and egg weight were recorded.

[0078] Experimental period: Each group was fed with corresponding feed for 6 weeks, and the daily feed intake, egg production rate and egg weight were recorded. The average data of the experimental period is shown in Table 1: Table 1. Mean and standard deviation of experimental period data

[0079] It can be seen that the experimental group 2 (added with 2% pomelo peel powder) has a lower feed intake due to high fiber, but the compound feed group (including experimental groups 3-11) has a feed intake close to or slightly higher than the control group. The egg production rate of the compound feed group (including experimental groups 3-11) is slightly higher than that of the control group, which may be related to the antioxidant and intestinal health improvement of high active ingredients (linalool, limonene). The egg weight of experimental group 2 and compound feed group (including experimental groups 3-11) is slightly higher than that of the control group. The feed intake, egg production rate and egg weight of experimental groups 4, 7 and 10 (i.e. compound feed with 0.2% addition) are slightly better than those of experimental group 2 (i.e. added with 2% pomelo peel powder).

[0080] In order to verify the improvement of the flavor of the eggs, egg samples were collected once every week during the experimental period, and 20 eggs were randomly selected from each group. The evaluators evaluated the raw eggs and cooked eggs (boiled in boiling water for 10 minutes) respectively. The evaluation dimensions included four main dimensions of appearance, aroma, taste and flavor. The appearance included four sub-indicators of raw egg white transparency (1-5 points, 1=turbid, 5=clear), raw egg yolk color (Lohse score, 1-15 points), cooked egg white whiteness (1-5 points, 5=white), and cooked egg yolk color (Lohse score, 1-15 points). The aroma included two sub-indicators of raw egg fishiness (1=no egg fishiness, 5=obvious egg fishiness) and cooked egg aroma (1-5 points, 1=almost no egg aroma, 5=obvious egg aroma). The taste included two sub-indicators of cooked egg white elasticity (1-5 points, 1=almost no elasticity, 5=full elasticity) and cooked egg yolk fineness (1-5 points, 1=rough, 5=fineness). The flavor was measured by the cooked egg deliciousness (1-5 points, 1=not delicious, 5=delicious). The evaluation data is shown in Table 2:

[0081] In order to verify the improvement of the flavor of the eggs, egg samples were collected once every week during the experimental period, and 20 eggs were randomly selected from each group. The evaluators evaluated the raw eggs and cooked eggs (boiled in boiling water for 10 minutes) respectively. The evaluation dimensions included four main dimensions of appearance, aroma, taste and flavor. The appearance included four sub-indicators of raw egg white transparency (1-5 points, 1=turbid, 5=clear), raw egg yolk color (Lohse score, 1-15 points), cooked egg white whiteness (1-5 points, 5=white), and cooked egg yolk color (Lohse score, 1-15 points). The aroma included two sub-indicators of raw egg fishiness (1=no egg fishiness, 5=obvious egg fishiness) and cooked egg aroma (1-5 points, 1=almost no egg aroma, 5=obvious egg aroma). The taste included two sub-indicators of cooked egg white elasticity (1-5 points, 1=almost no elasticity, 5=full elasticity) and cooked egg yolk fineness (1-5 points, 1=rough, 5=fineness). The flavor was measured by the cooked egg deliciousness (1-5 points, 1=not delicious, 5=delicious). The evaluation data is shown in Table 2: Table 2. Mean of sample evaluation data at the 3rd week and the 6th week

[0082] From the above evaluation results, it can be seen that the egg flavor improvement is in appearance (mainly egg yolk and egg white: compared with the control group, the color of the yolk of all the flavored groups (i.e. experimental groups 2-11) is much brighter and brighter, showing golden yellow, which gives people a warm and appetite in vision, and the color of the cooked egg white is whiter than the control group, which forms a contrast with the yolk and increases the visual appeal), aroma (the control group has a distinct egg smell, and the egg smell of all the flavored groups (i.e. experimental groups 2-11) is significantly reduced, and some flavored groups even have a slight egg smell, and a comfortable aroma is presented, which enhances the layer of egg flavor), taste (compared with the control group, the flavored group has better taste of egg yolk and egg white after cooking, and the egg yolk feels more delicate in the mouth, and the elasticity of the egg white is better), and taste (compared with the control group, the flavored group has a more delicious taste).

[0083] In summary, the 0.2% addition amount of the compound feed additive (corresponding to experimental groups 4, 7, 10) has better flavor improvement effect as a whole, while the compound feed additive B (corresponding to experimental groups 6, 7, 8) has better overall performance than the compound feed additive A (corresponding to experimental groups 3, 4, 5), and is almost not inferior to the compound feed additive C (corresponding to experimental groups 9, 10, 11), and the total amount of pomelo peel powder is reduced from the original 2% to about 0.1%, and the flavor improvement effect is maintained, greatly reducing the dependence on pomelo peel raw materials, and meeting the production needs of large-scale commercialization.

[0084] In summary, the compound feed additive for improving the flavor of eggs, the preparation process and the compound feed provided by the embodiments of the present application are prepared by analyzing the main components of pomelo peel, screening the main components affecting the flavor of eggs, and compounding the chemical components, pomelo peel powder and pomelo flavor extract (concentrating effective components such as limonene and polyphenols in pomelo peel, and then mixing with microcapsules and puffed corn flour to prepare) based on pomelo peel powder to obtain the compound feed additive for improving the flavor of eggs. The total addition amount of pomelo peel powder in the basic feed is reduced from 2% to 0.1%, and the flavor improvement effect is maintained, greatly reducing the dependence on pomelo peel raw materials, and meeting the production needs of large-scale commercialization.

[0085] In the formula of the compound feed additive for improving the flavor of chicken eggs, the grapefruit peel extract is combined with various terpenes and esters (such as linalyl acetate and myrcene) to mask the egg odor (such as pyridine and trimethylamine) through synergistic effect, while promoting the formation of aldehydes and ketones in cooked chicken eggs. Low threshold components (such as aromatic compounds and aldehydes) directly dominate the flavor, and high content aliphatic hydrocarbons serve as carriers without interfering with the overall flavor. During the preparation of grapefruit flavor extract, β-cyclodextrin and gum arabic (1:1 mixture) are used as wall materials to protect volatile substances (such as limonene) in the concentrated solution from oxidation and degradation, prolong the action time, and ensure the slow release and deposition of effective components in the intestinal tract of laying hens and into the egg yolk. Zeolite powder adsorbs odor substances such as trimethylamine and hydrogen sulfide in the intestinal tract, and defatted rice bran provides a uniform physical carrier to reduce the loss of active ingredients. Moreover, since the grapefruit peel powder contains pectin and cellulose, it can form a multi-level "adsorption network" with zeolite powder and organic carriers (rich in cellulose) to further fix volatile components and reduce the loss of flavor substances: activated zeolite powder can strongly adsorb small molecule terpenes such as linalool and limonene due to its porous structure with pore size of 0.4-1.2 nm, achieving molecular-level locking; the gel network can wrap zeolite particles, and cellulose fibers can be inserted between zeolite particles to prevent zeolite agglomeration, fill its large pores (>2 nm) and gaps, and reduce the loss of aroma during processing and storage; while rice bran fibers cover the surface and adsorb non-polar molecules such as myrcene through hydrophobic interaction, forming an outer slow-release layer. The polyphenols in grapefruit peel can enhance the immunity of laying hens, reduce the corruption of fatty acids caused by oxidative stress, and reduce the generation of odor substances (such as ammonia) in eggs. Zeolite powder can also adsorb harmful metabolites, improve the intestinal microecology, and indirectly improve the flavor of chicken eggs.

[0086] The compound scheme of natural flavor extraction (grapefruit flavor extract prepared based on grapefruit peel powder) + chemical components (such as linalool, linalyl acetate, limonene, vanillyl alcohol, geranyl acetate, myrcene, etc.) + natural grapefruit peel powder (grapefruit peel powder crushed to 80 mesh) can also improve the flavor of eggs well in the case of greatly reducing the amount of grapefruit peel powder (from 2% to about 0.1%). It has been verified by experiments that the improvement of egg flavor is in appearance (mainly egg yolk and egg white: compared with the control group, the color of the yolk of all the flavored groups is much brighter and brighter, showing golden yellow, which gives people a warm and appetite in vision, and the color of the cooked egg white is whiter than the control group, which increases the visual appeal), aroma (the control group has a distinct egg smell, the egg smell of all the flavored groups is significantly reduced, and some flavored groups even have no obvious egg smell, and the comfortable aroma increases the level of egg flavor), taste (compared with the control group, the flavored eggs have better taste of yolk and white after cooking, the yolk feels more delicate in the mouth, and the elasticity of the white is better), and taste (compared with the control group, the flavored eggs have more delicious taste).

[0087] The above only describes the embodiments of the present application and does not limit the protection scope of the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A compound feed additive for improving egg flavor, characterized in that: The compound feed additive includes the following substances in parts by weight: 20-40 parts of linalool, 5-10 parts of linalyl acetate, 2-4 parts of limonene, 1-2 parts of vanillyl alcohol, 0.7-1.4 parts of geranyl acetate, 5-10 parts of myrcene, 80 parts of grapefruit peel powder, 150 parts of carrier, and 70 parts of grapefruit flavor extract.

2. The compound feed additive for improving egg flavor according to claim 1, characterized in that: The carrier comprises 50 parts of an organic carrier and 100 parts of a functional carrier, the organic carrier is defatted rice bran, defatted bran or a combination of the two, and the functional carrier is zeolite powder.

3. The compound feed additive for improving egg flavor according to claim 1, characterized in that: The composition includes 20 parts of linalool, 5 parts of linalyl acetate, 2 parts of limonene, 1 part of vanillyl alcohol, 0.7 parts of geranyl acetate, 5 parts of myrcene, 80 parts of grapefruit peel powder, 150 parts of carrier, and 70 parts of grapefruit flavor extract.

4. The compound feed additive for improving egg flavor according to claim 1, characterized in that: 40 parts of linalool, 10 parts of linalyl acetate, 4 parts of limonene, 2 parts of vanillyl alcohol, 1.4 parts of geranyl acetate, 10 parts of myrcene, 80 parts of grapefruit peel powder, 150 parts of carrier, and 70 parts of grapefruit flavor extract.

5. The compound feed additive for improving egg flavor according to claim 1, characterized in that: 30 parts of linalool, 7.5 parts of linalyl acetate, 3 parts of limonene, 1.5 parts of vanillyl alcohol, 1 part of geranyl acetate, 7.5 parts of myrcene, 80 parts of grapefruit peel powder, 150 parts of carrier, and 70 parts of grapefruit flavor extract.

6. The compound feed additive for improving egg flavor according to any one of claims 1 to 5, characterized in that: The grapefruit flavor extract is obtained by subjecting grapefruit peel powder to headspace solid phase microextraction, followed by microencapsulation and carrier mixing.

7. A process for preparing a compound feed additive for improving egg flavor according to any one of claims 1 to 6, characterized in that: include: S1: fresh grapefruit peels are washed, dried at low temperature, crushed, and passed through an 80-mesh sieve to obtain grapefruit peel powder; S2: preparing grapefruit flavor extract by taking grapefruit peel powder; S3: mixing linalool, linalyl acetate, limonene, vanillyl alcohol, geranyl acetate, and myrcene in proportion to obtain a flavor component mixture; S4: spraying the flavor component mixture into the activated zeolite powder in an atomized form; S5: Add the zeolite powder after the flavor components are absorbed, the grapefruit peel powder, and the defatted rice bran into a double cone mixer, fill with nitrogen for protection, and mix at a low speed for 30 minutes; S6: adding the prepared grapefruit flavor extract into the double-cone mixer, and continuing to mix at a low speed for 30 minutes to obtain the prepared compound feed additive for improving egg flavor.

8. The process for preparing the compound feed additive for improving egg flavor according to claim 7, characterized in that: The grapefruit flavor extract is prepared as follows: S21: performing headspace solid phase microextraction on grapefruit peel powder to obtain grapefruit flavor extract; S22: concentrating the grapefruit flavor extract and recovering the solvent to obtain a grapefruit flavor concentrate; S23: performing microencapsulation treatment on the grapefruit flavor concentrate to form microcapsules, wherein the microcapsule wall material is a 1:1 mixture of β-cyclodextrin and gum arabic; S24: After baking and sterilizing, puffed corn flour with a particle size of 80 mesh is mixed with microcapsules in a ratio of 9:1 to obtain a uniformly mixed grapefruit flavor extract.

9. A compound feed for improving the flavor of eggs, characterized in that: The compound feed additive is prepared by adding the compound feed additive for improving egg flavor according to claim 7 to the basic feed.

10. The compound feed for improving egg flavor according to claim 9, characterized in that: The addition ratio of compound feed additives is 0.1%-0.3%.

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