Huyou peel pomace flavor liquid as well as preparation method and application thereof

Abstract

The invention provides grapefruit peel pomace flavored liquid as well as a preparation method and application thereof, and belongs to the technical field of food processing. The invention provides a preparation method of grapefruit peel pomace flavor liquid, which takes grapefruit peel pomace as a raw material, and treats the peel pomace by using compound enzyme, so that not only can free flavor substances bound by pectin and cellulose in the peel pomace be fully dissolved out, but also glycoside bound flavor substances which are richer in reserve but cannot be directly perceived originally can be released through enzymolysis reaction, and the flavor liquid is rich in flavor. The recovered flavor substances are richer, the overall fragrance is more harmonious and full, the natural characteristics of the Huyou are obvious, the flavor quality of food can be effectively improved, the nutritional value is improved, and the increasingly-upgraded comprehensive consumption requirements of consumers are met. The grapefruit peel pomace flavor liquid can be diluted in concentration and adjusted in addition amount according to requirements in practical application, and is wider in application range and simpler to operate.

Description

Technical Field

[0001] The invention belongs to the technical field of food processing, and in particular relates to a pomelo peel residue flavor liquid and a preparation method and application thereof. Background Art

[0002] Pomelo Citrus aurantium 'Changshanhuyou' is native to Changshan, Zhejiang Province. It is a hybrid of pomelo and sour orange and has a long history of cultivation. When it reaches the right maturity, the pomelo fruit is bright yellow in appearance, tastes moderately sweet and sour, and has a slightly bitter taste. After eating, the aftertaste is fresh and refreshing, and has a unique and comfortable natural aroma that combines citrus, floral, grass and wood properties. At the same time, pomelo also has pharmacological effects such as cooling and removing heat, relieving cough and reducing phlegm. The unique flavor and nutritional value make pomelo the first choice for deep-processed citrus products.

[0003] The deep processing of pomelo is generally to extract juice, which will produce a lot of waste peel residue. Compared with pomelo juice, pomelo peel contains more abundant bioactive substances, including essential oils, limonoids, and flavonoids such as naringin and hesperidin. The content of volatile aromatic compounds such as D-limonene and γ-terpinene, as well as total phenols and total flavonoids in the peel residue can reach 10 to 100 times, and the antioxidant capacity is also much higher than that of juice.

[0004] The deep processing of pomelo peel residue is mostly used to extract bioactive ingredients, or as raw materials for the production of jams, fillings, etc. However, due to its bitter taste, its market acceptance and popularity are still relatively low. It can only be landfilled in large quantities or used to produce feed fertilizers, with low added value and heavy environmental burden. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a pomelo peel residue flavor liquid and a preparation method and application thereof, which improves the utilization rate and utilization value of the peel residue while providing a fuller flavor with more natural pomelo characteristics and has strong nutritional activity, thereby providing a new idea for the value-added utilization of pomelo peel residue and the flavor enhancement of pomelo juice.

[0006] The first invention object of the present invention is to provide a method for preparing a pomelo peel residue flavor liquid, comprising the following steps: crushing the pomelo peel residue into a slurry, enzymolyzing the slurry with an enzyme mixture, and inactivating the enzyme in the supernatant obtained after filtering to obtain the pomelo peel residue flavor liquid; The enzyme mixture comprises pectinase, naringinase and beta-glucosidase.

[0007] In a preferred embodiment of the present invention, before the enzymatic hydrolysis, the enzyme mixture is activated, and the activation method includes ultrasonic activation.

[0008] In a preferred embodiment of the present invention, the temperature of the ultrasonic activation is 25° C., the power is 50-200 W, and the time is 10-15 min.

[0009] In a preferred embodiment of the present invention, the mass ratio of pectinase, naringinase and β-glucosidase in the enzyme mixture is (0.05-0.45): (0.15-0.75): (0.15-0.75).

[0010] In a preferred embodiment of the present invention, the pectinase comprises: protopectinase, polygalacturonase, lyase and pectinesterase; The composition of the naringinase includes α-L-rhamnosidase and β-D-glucosidase.

[0011] In a preferred embodiment of the present invention, the enzymatic hydrolysis using the enzyme mixture is accompanied by stirring, the enzymatic hydrolysis temperature is 30-60°C, the time is 30-120 min, and the stirring speed is 800-1200 rpm.

[0012] In a preferred embodiment of the present invention, after obtaining the peel residue flavor liquid, the process further comprises centrifuging and filtering to obtain an enzymatic hydrolysis clear liquid; The centrifugal speed is 4000-6000 rpm, and the time is 0.8-1.5 min; The filtering includes filtering through 100 mesh gauze.

[0013] The second invention objective of the present invention is to provide a pomelo peel residue flavored liquid prepared by the above preparation method.

[0014] The third invention objective of the present invention is to provide the use of the above-mentioned pomelo peel residue flavor liquid in the preparation of food additives.

[0015] A fourth inventive object of the present invention is to provide a pomelo flavored food comprising the pomelo peel residue flavored liquid.

[0016] Beneficial effects: The present invention provides a method for preparing a pomelo peel residue flavor liquid, which uses pomelo peel residue as a raw material, is natural and safe in source, and is environmentally friendly. It can efficiently recycle the flavor substances and active ingredients of the discarded pomelo peel residue, reduce the environmental pollution and burden of the peel residue treatment, and realize the deep application of the whole pomelo fruit in the field of food processing. The present invention uses a composite enzyme to treat the peel residue, which can not only fully dissolve the free flavor substances bound by pectin and cellulose in the peel residue, but also release the glycoside-bound aroma substances with richer reserves but originally not directly perceived through enzymatic hydrolysis. The recovered flavor substances are richer, the overall fragrance is more coordinated and full, and the natural characteristics of pomelo are obvious. It can effectively improve the flavor quality of the beverage, provide nutritional value, and meet the increasingly upgraded comprehensive consumption needs of consumers. The present invention adopts the composite use of pectinase, naringinase and β-glucosidase, which specifically, specifically and efficiently promotes the dissolution and release of flavor substances in the peel residue, and interrupts the glycosidic bonds of the bound flavor substances from the chemical structure level, so that the perceptible aroma substances are released, which plays a role in enhancing the fragrance. The invention adopts a simple and efficient method, greatly recovers the flavor substances in the pomelo peel residue, improves the utilization value of the peel residue, and increases the characteristic flavor of the food pomelo. In particular, the flavor liquid is derived from natural plants, the peel residue is utilized in a green and high-value manner, and it is environmentally friendly.

[0017] The present invention provides a pomelo peel residue flavor liquid prepared by the composite enzymatic hydrolysis method. In practical applications, the concentration can be diluted and the addition amount can be adjusted according to needs, so the application range is wider and the operation is simpler. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a picture of the residue after squeezing the whole grapefruit juice in a cup; Figure 2 Quantitatively describe the radar chart for the flavor profile; Figure 3 It is a three-dimensional peak diagram of the GC-IMS measurement spectrum of the blank water extraction case, the optimized case and the temperature increase case, which represents the blank water extraction case, the optimized case and the temperature increase case from left to right; Figure 4 The two-dimensional GC-IMS spectra of the blank water extraction case, the optimized case and the temperature increase case; Figure 5 for Figure 4 Comparison of 2D GC-IMS spectra; Figure 6 The total ion current diagram (three-dimensional) of the blank water extraction case, the optimized case, and the temperature increase case represents the blank water extraction case, the optimized case, and the temperature increase case from top to bottom. DETAILED DESCRIPTION

[0019] The invention provides a method for preparing a pomelo peel residue flavor liquid, comprising the following steps: crushing the pomelo peel residue into slurry, enzymolyzing the slurry with an enzyme mixture, and inactivating the enzyme in the supernatant obtained after filtration to obtain the pomelo peel residue flavor liquid; The enzyme mixture comprises pectinase, naringinase and beta-glucosidase.

[0020] The pomelo peel residue of the present invention is the residue after pomelo processing. Figure 1 The residue after whole-fruit cup-style juicing of the pomelo shown includes a white skin layer, an oil cell layer, seeds, and a sac coat pomace. Before the pomelo peel pomace is crushed and pulped, the seeds are removed to avoid the problem of product bitterness caused by a high content of limonin in the seeds.

[0021] The present invention prepares the pomelo peel residue into pulp, including crushing and mixing the pomelo peel residue and pure water in a certain proportion to form raw fruit pulp; wherein the material-liquid ratio can be 1:2, and the peel residue is crushed until the particle size is less than 2mm.

[0022] The present invention utilizes an enzyme mixture to perform enzymolysis treatment on the slurry, wherein the enzyme mixture comprises pectinase, naringinase and beta-glucosidase, and the mass ratio of the three types of enzymes is (0.05-0.45): (0.15-0.75): (0.15-0.75), wherein the composition of the pectinase comprises: protopectinase, polygalacturonase, lyase and pectinesterase, and in one embodiment, purchased food-grade pectinase is used for research, which is purchased from Zhejiang Tianhe Food Biology Co., Ltd.; the composition of the naringinase comprises alpha-L-rhamnosidase and beta-D-glucosidase, and in one embodiment, purchased food-grade naringinase is used for research, which is purchased from Zhejiang Tianhe Food Biology Co., Ltd.

[0023] When preparing the enzyme mixture of the present invention, the three types of enzymes are mixed and dissolved in a certain proportion, specifically comprising: 0.05-0.45% of the weight of the peel residue pectinase, 0.15-0.75% of the weight of the peel residue naringinase and 0.15-0.75% of the weight of the peel residue be weighed and mixed respectively, and dissolved in 10% of the weight of the peel residue in pure water, wherein the weight of the pectinase can be 0.05%, 0.15%, 0.25%, 0.35% or 0.45% of the weight of the peel residue, and in one embodiment, the amount of pectinase is 0.15%; the weight of the naringinase can be 0.15%, 0.30%, 0.45%, 0.60% or 0.75% of the weight of the peel residue, and in one embodiment, the amount of the naringinase is 0.6%; the weight of the β-glucosidase can be 0.15%, 0.30%, 0.45%, 0.60% or 0.75% of the weight of the peel residue, and in one embodiment, the amount of the β-glucosidase is 0.6%.

[0024] The pectinase of the present invention can convert insoluble pectin into water-soluble pectin under the conditions of 30-55°C and pH value of 4.0-6.0, crack pectin polymers, randomly cut off the ester bond between the methoxy group of water-soluble pectin and galacturonic acid, and hydrolyze the polygalacturonic acid chain, thereby playing the role of clarifying and improving the juice yield and the dissolution of effective components; the β-glucosidase can efficiently hydrolyze the β-D-glucose glycosidic bond at the non-reducing end under the conditions of 35-65°C and pH value of 3.5-6.0, release β-D-glucose and corresponding aroma ligands, thereby improving the flavor; the naringinase can hydrolyze naringin into rhamnose and prunin under the conditions of 50-60°C and pH value of 3.5-6.0, the α-L-rhamnosidase can hydrolyze naringin into rhamnose and prunin, and the β-glucosidase can further hydrolyze prunin into non-bitter naringenin and glucose, thereby removing bitterness and enhancing fragrance.

[0025] In the present invention, the enzyme mixture is activated and then added to the skin residue slurry for enzymolysis. The activation can be ultrasonic activation. The temperature of the ultrasonic activation is 25°C, the time is 10-15 minutes, and the power is 50-200W. For example, the power can be 50W, 100W, 150W or 200W. In one embodiment, the activation is performed at a power of 150W. The low-intensity ultrasonic activation of the present invention can promote a more efficient combination reaction between the substrate and the enzyme, improve the reaction efficiency, shorten the heating time, and optimize the aroma profile.

[0026] The present invention adds the activated complex enzyme to the peel and residue pulp, and performs enzymolysis by magnetic stirring in a water bath. The temperature of the enzymolysis is 30-60°C, such as 30, 35, 40, 45, 50, 55 or 60°C. In one embodiment, the enzymolysis is performed at a temperature of 50°C. The stirring speed can be 800-1200 rpm, and the magnetic stirring water bath time is 30-120 min, such as 30 min, 45 min, 60 min, 75 min, 90 min or 120 min. In one embodiment, the enzymolysis is performed for 90 min.

[0027] The invention kills the enzyme after the enzymolysis is completed, and the enzyme killing can be carried out by boiling for 8 minutes, and then filtering and separating the peel residue mixture after enzymolysis to obtain the peel residue enzymolysis flavor liquid. The centrifugal speed of the invention is 4000-6000 rpm, the time is 1.8-1.5 minutes, and the enzymolysis clear juice is obtained by filtering and separating through 100 mesh gauze.

[0028] The present invention also provides a pomelo peel residue flavor liquid prepared by the preparation method.

[0029] The pomelo peel residue flavor liquid prepared by the method contains terpinolene, limonene, terpinene, myrcene and 3-carene with fruity aromas similar to those of sweet orange, lemon and the like; decanal, linalool oxide, nonanal, 4-isopropyltoluene and ethyl acrylate with pleasant floral aromas; 2,3-pentanedione, 2-ethylfuran and methyl acetate with sweet aromas; n-hexanal and α-pinene with fresh green odors; and the content of volatiles bringing fat, waxy and sharp sour smells is lower.

[0030] The invention also provides application of the pomelo peel residue flavor liquid in preparing food additives.

[0031] In one embodiment of the present invention, the peel residue is treated with a composite enzyme after ultrasonic activation, which can fully dissolve the free flavor substances bound by pectin and cellulose in the peel residue, and can also release the glycoside-bound aroma substances with richer reserves but originally not directly perceived through enzymatic reaction, so that the recovered flavor substances are richer, the overall fragrance is more coordinated and full, the natural characteristics of pomelo are obvious, and the flavor quality of the beverage can be effectively improved, the nutritional value is provided, and the comprehensive consumption needs of consumers that are increasingly upgraded are met. The operation method is simple and efficient, and the concentration dilution and the addition amount can be adjusted according to the needs in practical applications, and the application range is wider.

[0032] The invention provides a pomelo flavored food comprising the pomelo peel residue flavored liquid.

[0033] The present invention does not specifically limit the type of the food, and it may be, for example, a beverage, or other food that can be prepared to have a certain flavor.

[0034] In order to further illustrate the present invention, a pomelo peel residue flavor liquid, a preparation method and an application provided by the present invention are described in detail below in conjunction with examples, but they should not be construed as limiting the scope of protection of the present invention.

[0035] Unless otherwise specified, the methods used in the embodiments of the present invention are conventional methods in the art, some of which are as follows: 1. Aroma and taste sensory scoring experiment: An 8-member sensory evaluation team was established, including 5 women and 3 men, with an average age of 24 years old. They were screened and trained in accordance with GB / T 16291.1-2012 "General Guidelines for Selection, Training and Management of Sensory Analysis Evaluators" and GB / T 15549-2022 "Introduction and Training of Evaluators in Sensory Analysis Methodology, Detection and Identification of Odors", and all had rich professional sensory evaluation experience. The overall score and profile quantitative description analysis of aroma and taste were performed from low to high 1 to 9 points.

[0036] Table 1 Aroma and taste sensory scoring table

[0037] 2. Recovery rate determination: Weigh the flavor liquid obtained by centrifugal filtration and calculate the recovery rate by comparing it with the mass of the enzymatic hydrolysis raw material (skin residue slurry): , formula Ⅰ.

[0038] 3. Determination of volatile components by gas phase-ion mobility spectrometry (GC-IMS): The chromatographic column was MXT-WAX (30 m×0.53 mm, 1 μm), and the drift gas and carrier gas were high-purity nitrogen (purity 99.999%). 2 mL of sample was taken into a 20 mL headspace injection bottle, and cyclohexanone (0.5 mg / mL) was added as an internal standard. The sealed headspace bottle was incubated at 40°C, 15 min, 500 rpm shaking, and the injection needle temperature was 85°C; the headspace injection volume was 500 μL. Each sample was measured three times.

[0039] The sample was initially separated in the chromatographic column by program pressure rise (flow rate), and the analysis time was 40 minutes. The flow rate of the carrier gas (EPC2) was set as follows: 2 mL / min for 2 minutes; 2-10 minutes, uniformly increased to 10 mL / min; 10-30 minutes, uniformly increased to 100 mL / min; 30-40 minutes, uniformly maintained at 100 mL / min. The molecules to be measured then entered the migration tube and were separated for the second time under the action of the electric field and the reverse drift gas. The flow rate of the drift gas (EPC1) was constant at 75 mL / min.

[0040] Qualitative analysis: Based on GC retention index (RI) and IMS relative migration time, the compounds are matched with the built-in GC×IMS database.

[0041] Quantitative analysis: Semi-quantification was performed using the Quantification function based on peak color and peak volume.

[0042] 4. GC×GC-TOF MS volatile component determination and relative odor activity (ROAV) determination: Take 2 mL of sample in a 20 mL headspace injection bottle, incubate at 80 ° C for 10 min, and adsorb the sample with the aged SPME extraction head at 80 ° C for 25 min. After the adsorption is completed, transfer it to the injection port and desorb at 250 ° C for 5 min.

[0043] Chromatographic conditions: The LECO Pegasus BT 4D GC×GC-TOF MS chromatographic system consists of an Agilent 8890A gas chromatograph, a two-stage jet modulator and a split / splitless injection module, and the mass spectrometer system is a high-resolution TOF mass spectrometer. The separation system includes a first-dimensional chromatographic column: DB-Heavy Wax (30m×250μm×0.5μm) and a second-dimensional chromatographic column Rxi-5Sil MS (2m×150μm×0.15μm). High-purity helium was used as the carrier gas with a constant flow rate of 1.0mL / min. The initial temperature of the first-dimensional chromatographic column was 50℃, maintained for 2min, and then increased to 230℃ at a rate of 5℃ / min and maintained for 5min. The temperature program of the second-dimensional chromatographic column was 5℃ higher than that of the first-dimensional chromatographic column, the modulator temperature was always 15℃ higher than the column temperature of the second-dimensional chromatographic column, and the modulation period was 6.0s. The injection port temperature was 250℃.

[0044] Mass spectrometry conditions: mass spectrometry transmission line temperature was 250°C, ion source temperature was 250°C, acquisition rate was 200 spectra / s, electron bombardment source was 70 eV, detector voltage was 1960 V, and mass spectrometry scanning range was m / z35-550.

[0045] ROAV calculation: Generally, the larger the ROAV, the greater the contribution of the substance to the flavor. Compounds with ROAV ≥ 1 are set as the key compounds that constitute the overall flavor. The ROAV of the compound with the greatest contribution to the sample flavor is 100. The ROAV of other compounds is calculated according to Formula II: , formula II; Where: C i and T i are the semi-quantitative results and odor thresholds of each volatile compound / (mg / L); C stan and T stan They are the semi-quantitative results of the compound that contributes most to the sample flavor and the odor threshold / (mg / L), respectively.

[0046] Example 1 Preparation method of leather residue flavor liquid: Step 1, processing the raw material of the pomelo peel residue extract: crushing and mixing the pomelo peel residue and purified water in a certain proportion to form a raw material pulp; Step 2, preparation and activation of complex enzyme: three enzymes are mixed in a certain proportion and dissolved in a certain volume of pure water, and activated under ultrasound; Step 3, adding the activated complex enzyme into the peel pulp, mixing and enzymolysis by magnetic stirring in a water bath; Step 4, filtering and separating the peel residue mixture after enzymatic hydrolysis to obtain the peel residue enzymatic hydrolysis flavor liquid.

[0047] 1. Selection of solid-liquid ratio for pulping Single factor extraction experiments were carried out with solid-to-liquid ratios of 1:1, 1:2, and 1:3 (the "solid" here refers to the fresh weight peel residue), and the other factors were fixed as follows: enzymatic hydrolysis temperature 40°C, enzymatic hydrolysis time 75 min, ultrasonic power 0 W, pectinase 0.15%, naringinase 0.3%, and β-glucosidase 0.3%.

[0048] Table 2 Recovery and aroma scores at different solid-liquid ratios

[0049] The results are shown in Table 2. When the solid-liquid ratio was 1:1, the aroma score was high, but the water and skin residue were strongly combined, and the extraction recovery rate was low. When the solid-liquid ratio was 1:3, the aroma was thin and the sensory score was low. When the solid-liquid ratio was 1:2, the recovery rate and aroma score were more appropriate, and the pH range when the solid-liquid ratio was 1:2 was between 3 and 5, which was within the optimal reaction condition range of the complex enzyme. The experiments were then carried out with a solid-liquid ratio of 1:2.

[0050] 2. Single factor optimization experiment at different enzymatic hydrolysis temperatures The enzymatic hydrolysis was carried out at 30°C, 40°C, 50°C and 60°C, respectively, and the other factors were fixed as follows: enzymatic hydrolysis time 75 min, ultrasonic power 0 W, pectinase 0.15%, naringinase 0.3%, β-glucosidase 0.3%.

[0051] Table 3 Sensory scores at different enzymatic hydrolysis temperatures

[0052] The results are shown in Table 3. At 50°C, the aroma score was the highest, and the bitterness acceptance and taste comprehensive scores were the highest, so 50°C was selected as the subsequent enzymatic hydrolysis temperature.

[0053] 3. Single factor optimization experiment under different pectinase addition amounts 0%, 0.05%, 0.15%, 0.25%, 0.35% and 0.45% pectinase were added respectively, and other factors were fixed as follows: enzymatic hydrolysis temperature 50℃, enzymatic hydrolysis 75min, ultrasonic power 0W, naringinase 0.3%, and β-glucosidase 0.3%.

[0054] Table 4 Sensory scores at different pectinase addition levels

[0055] The results are shown in Table 4. Based on the aroma score, bitterness acceptance and taste score, and the actual energy-saving needs, 0.15% was selected as the optimal pectinase addition amount.

[0056] 4. Single factor optimization experiment under different naringinase addition amounts 0%, 0.15%, 0.30%, 0.45%, 0.60% and 0.75% naringinase were added respectively, and other factors were fixed as follows: enzymatic hydrolysis temperature 50℃, enzymatic hydrolysis 75min, ultrasonic power 0W, pectinase 0.15%, and β-glucosidase 0.3%.

[0057] Table 5 Sensory scores at different naringinase addition levels

[0058] The results are shown in Table 5. Based on the aroma score, bitterness acceptance and taste score, and the actual energy-saving needs, 0.6% was selected as the optimal naringinase addition amount.

[0059] 5. Single factor optimization experiment under different β-glucosidase addition amounts 0%, 0.15%, 0.30%, 0.45%, 0.60% and 0.75% β-glucosidase were added respectively, and other factors were fixed as follows: enzymatic hydrolysis temperature 50℃, enzymatic hydrolysis 75min, ultrasonic power 0W, pectinase 0.15%, naringinase 0.3%.

[0060] Table 6 Sensory scores at different β-glucosidase addition levels

[0061] The results are shown in Table 6. Based on the aroma score, bitterness acceptance and taste score, and the actual energy-saving needs, 0.6% was selected as the optimal β-glucosidase addition amount.

[0062] 6. Single factor optimization experiment under different ultrasonic power activation Ultrasonic activation was performed at room temperature (25°C) for 10 min. The composite enzyme was treated with 0 W (no ultrasound), 50 W, 100 W, 150 W, and 200 W power, and other factors were fixed as follows: enzymatic hydrolysis temperature 50°C, enzymatic hydrolysis 75 min, pectinase 0.15%, naringinase 0.3%, and β-glucosidase 0.6%.

[0063] Table 7 Sensory scores at different ultrasonic powers

[0064] The results are shown in Table 7. Based on the aroma score, bitterness acceptance and taste score, 150 W was selected as the optimal ultrasonic activation treatment power.

[0065] 7. Single factor optimization experiment under different enzymatic hydrolysis time The enzymatic hydrolysis times were 30 min, 60 min, 75 min, 90 min, 120 min, 150 min and 180 min respectively, and the other factors were fixed as follows: enzymatic hydrolysis temperature 50 °C, ultrasonic power 0 W, pectinase 0.15%, naringinase 0.3% and β-glucosidase 0.3%.

[0066] Table 8 Sensory scores at different enzymatic hydrolysis times

[0067] The results are shown in Table 8. Taking into account the unpleasant odor intensity, aroma score, bitterness acceptance and taste score, combined with the actual energy-saving needs, 90 min was selected as the optimal enzymatic hydrolysis temperature.

[0068] 8. Flavor characterization results of three groups: optimization case, blank water extraction case, and temperature increase case Table 9 Experimental conditions of three groups of examples

[0069] 8.1 Quantitative description of the flavor profiles of the three experimental cases Figure 2 As shown in the figure, the flower, sweet, fruity and green aromas of the optimized example are stronger, the unpleasant smell is the weakest, and the aftertaste freshness and refreshing perception are significantly stronger; the overall flavor is richer and fuller, and the acceptance of bitterness and astringency is higher. Although the acceptance of bitterness and astringency in the warming example is also higher, the aftertaste freshness and refreshing perception are poor, the unpleasant smell is stronger, and the fruity and floral aromas are significantly weaker. The blank water extraction example that did not participate in enzymatic hydrolysis scored the lowest in all aspects of taste, and the flower and sweet aromas were weak.

[0070] 8.2 GC-IMS aroma profile The blank water extraction case, optimization case, and temperature increase case were measured by GC-IMS spectra, and the three-dimensional peak diagrams are shown in Figure 3 As shown, the two-dimensional map is Figure 4 As shown ( Figure 4 Each bright spot in the graph represents a peak of a substance, and different drift times at the same retention time represent monomers and dimers of the same substance). Figure 5 As shown ( Figure 5 The blank water extraction example is used as a reference. Red indicates that the substance content is higher, and blue indicates that the substance content is lower).

[0071] The main volatiles detected are listed in Table 10. M represents monomer, D represents dimer, Tr represents trimer, and Te represents tetramer. All of the above are the forms in which substances react in ion mobility spectra. The semi-quantitative data obtained from the forms with higher polymer multiples are more quantitatively valuable. After the optimized enzymatic hydrolysis process, the flavor liquid of pomelo peel residue contains terpinolene, limonene, terpinene, myrcene and 3-carene, which give fruity aromas similar to sweet orange and lemon; decanal, linalool oxide, nonanal, 4-isopropyltoluene and ethyl acrylate, which give pleasant floral aroma; 2,3-pentanedione, 2-ethylfuran and methyl acetate, which give sweet aroma, and hexanal and α-pinene, which give fresh green smell, and the content is higher. The content of volatiles that bring fat, waxy and sharp sour taste is less.

[0072] Table 10 Main detected volatiles and their semi-quantitative results

[0073]

[0074]

[0075] 8.3 GC×GC-TOF MS Volatile Determination and Relative Odor Activity Value (ROAV) Determination Results Total ion current diagram (3D) of blank water extraction example, optimization example, and temperature increase example Figure 6 As shown, the volatile compounds with ROAV≥1 that mainly contribute to the aroma are listed in Table 11. In Table 11, “ / ” means that the ROAV of the corresponding substance in this group is less than 1. There are more substances with aroma contribution values ​​in the optimized example, including acetaldehyde that provides fruity flavor and ethyl acrylate that provides sweetness. Among the substances with ROAV≥1, the aroma contribution values ​​of 2-nonenal, 2-octenal, heptaldehyde, 2-methylbutanal, citronellal acetate, 2,3-butanedione, etc. in the optimized example are higher, giving the flavor liquid a higher green, fruity, and sweet aroma, and the overall flavor is richer.

[0076] Table 11 Volatile compounds with ROAV≥1 that mainly contribute to aroma

[0077] 8.4 The optimized flavor liquid was mixed with pomelo original juice in a ratio of 1:1, and the sensory scores were compared. The results are shown in Table 12. After adding the flavor liquid, the sweetness, flowery aroma, and green aroma of the juice were significantly improved, the taste was more refreshing and fresh, and the overall flavor was fuller and richer.

[0078] Table 12 Flavor evaluation score table

[0079] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for preparing a pomelo peel residue flavored liquid, characterized in that: The following steps are involved: After the pomelo peel residue is crushed into a slurry, the slurry is enzymatically hydrolyzed by using an enzyme mixture, and the enzyme is inactivated in the supernatant obtained after filtration to obtain the pomelo peel residue flavor liquid; The enzyme mixture comprises pectinase, naringinase and beta-glucosidase.

2. The preparation method according to claim 1, characterized in that: Before the enzymolysis, the enzyme mixture is activated, and the activation method includes ultrasonic activation.

3. The preparation method according to claim 2, characterized in that: The temperature of the ultrasonic activation is 25° C., the power is 50-200 W, and the time is 10-15 min.

4. The preparation method according to claim 1 or 2, characterized in that: The mass ratio of pectinase, naringinase and beta-glucosidase in the enzyme mixture is (0.05-0.45): (0.15-0.75): (0.15-0.75).

5. The preparation method according to claim 4, characterized in that: The pectinase comprises: protopectinase, polygalacturonase, lyase and pectinesterase; The composition of the naringinase includes α-L-rhamnosidase and β-D-glucosidase.

6. The preparation method according to claim 5, characterized in that: The enzyme mixture is stirred during enzymolysis, the enzymolysis temperature is 30-60° C., the time is 30-120 min, and the rotation speed during stirring is 800-1200 rpm.

7. The preparation method according to claim 1, characterized in that: After obtaining the peel residue flavor liquid, the method further includes centrifuging and filtering to obtain an enzymatic clear liquid; The centrifugal speed is 4000-6000 rpm, and the time is 0.8-1.5 min; The filtering includes filtering through 100 mesh gauze.

8. A pomelo peel residue flavored liquid prepared by the preparation method according to any one of claims 1 to 7.

9. Use of the pomelo peel residue flavor liquid according to claim 8 in the preparation of food additives.

10. A pomelo flavored food comprising the pomelo peel residue flavored liquid according to claim 8.

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