Whole citrus gonggan fruit juice beverage and preparation method thereof

Abstract

The invention belongs to the technical field of food processing, and particularly relates to a citrus gonggan whole fruit juice beverage and a preparation method thereof. The citrus gonggan whole-fruit juice provided by the invention is prepared by the following steps: performing whole-fruit juicing on a citrus gonggan raw material by adopting technologies such as fruit juice micronization combined with compound enzyme efficient catalysis and the like, performing wet-process superfine grinding treatment on tissues such as pulp and peel, effectively crushing, dispersing, homogenizing, emulsifying and sterilizing, and then adding compound enzyme for enzymolysis, debitterizing and sterilizing to obtain the citrus gonggan whole-fruit juice. The citrus gonggan whole fruit juice beverage prepared by the preparation method disclosed by the invention has the advantages of strong citrus gonggan flavor, moderate viscosity, rich taste, rich nutrition and high stability, and a theoretical basis is provided for developing high-quality citrus gonggan whole fruit juice products.

Description

Technical Field

[0001] The present invention belongs to the technical field of food processing, and particularly relates to a whole fruit juice beverage of Gonggan oranges and a preparation method thereof. Background Art

[0002] The Lingnan region is a key citrus-producing area in China, ranking fourth in the country in terms of output. Due to its unique geographical and climatic factors, it has the advantages of a short growth period of citrus, high sugar content, unique flavor, and high nutritional value. As a natural hybrid variety of oranges and tangerines, Gonggan oranges possess the advantages of both oranges and tangerines, with beautiful fruit shapes, golden fruit colors, thin skins and few seeds, crispy and melt-in-the-mouth flesh, sweet and fragrant honey, and excellent pulp flavors. In recent years, with the increase in output, the progress of storage and processing technologies, and the realization of year-round supply, citrus fruits have now become an important source of dietary nutrition. They can be eaten fresh or processed into fruit juices, jams, or desserts.

[0003] Currently, beverage production is the main direction of citrus fruit processing. For example, Liu Gongliang et al. published a paper titled "Optimization of the Process for Producing Gonggan Orange Juice Using Pectinase". This paper disclosed the optimal enzymatic hydrolysis process conditions for the production of Gonggan orange juice from Deqing. Using pectinase to produce Gonggan orange juice, under the optimal process conditions of an enzyme addition amount of 0.06%, an enzymatic hydrolysis time of 2.5 h, an enzymatic hydrolysis temperature of 45 °C, and an enzymatic hydrolysis pH of 4.0, the juice yield of Gonggan oranges from Deqing can reach up to 70.03% at most. This research laid a foundation for the deep processing of Gonggan orange juice from Deqing.

[0004] Patent document CN112841468A discloses a Gonggan orange juice beverage and a preparation method thereof. The raw materials of this Gonggan orange juice beverage include concentrated Gonggan orange juice, granulated sugar, high fructose syrup, sweetening regulators, acidifying regulators I, acidifying regulators II, antioxidants, thickeners, edible pigments, preservatives, edible flavors, and water. The preparation method is as follows: dissolve concentrated Gonggan orange juice, granulated sugar, high fructose syrup, sweetening regulators, acidifying regulators I, acidifying regulators II, and antioxidants in water; dissolve thickeners, edible pigments, and preservatives in water respectively, mix all the raw materials evenly, then fill, sterilize, and cool to room temperature to obtain the Gonggan orange juice beverage. This Gonggan orange juice beverage has a good Gonggan orange flavor, is sweet and sour, and is suitable for drinking.

[0005] However, after Gonggan oranges undergo processing such as juicing, sterilization, and storage, the phenomenon of enhanced bitterness and volatilization of aromatic substances will occur, which not only affects the taste of Gonggan orange juice but also the product quality of Gonggan orange juice. At the same time, a large amount of Gonggan orange peel residue will be generated during the processing of Gonggan oranges, and the peel residue contains rich nutritional components such as vitamins, amino acids, crude fat, crude fiber, soluble sugar, acid, and pectin. Except for a small amount of this peel residue being used for extracting pectin, essential oils, and flavonoids, most of it has not been well utilized, thus causing resource waste and environmental pollution.

[0006] Therefore, it is an urgent and difficult problem to be solved at present to research and develop a preparation process for ponkan orange juice that can make full use of ponkan oranges, improve the economic added value of ponkan oranges, and at the same time solve problems such as juice browning, post-turbidity, nutrient loss, and aroma substance dissipation during the storage of ponkan orange juice. Summary of the Invention

[0007] In order to solve the defects of the prior art, the present invention provides a whole-fruit ponkan orange juice beverage and a preparation method thereof. The whole-fruit juice preparation of ponkan oranges in the present invention adopts technologies such as juice microatomization combined with highly efficient catalysis of composite enzymes. After squeezing the whole ponkan orange raw materials to obtain whole-fruit juice, the pulp, peel and other tissues are subjected to wet ultrafine grinding treatment, effectively crushing, dispersing, homogenizing, emulsifying and sterilizing them, and then adding composite enzymes for enzymatic hydrolysis to obtain a whole-fruit ponkan orange juice beverage, thereby realizing the full utilization of ponkan orange raw materials and enhancing the economic value of ponkan orange raw materials.

[0008] The specific technical solution is as follows:

[0009] The present invention provides a preparation method for a whole-fruit ponkan orange juice beverage, comprising the following steps:

[0010] Step S1: Wash and crush ponkan oranges to obtain whole-fruit pulp, mix the whole-fruit pulp with ultrapure water at a volume ratio of 1:1, and perform wet ultrafine grinding treatment and homogenization to obtain a primary whole-fruit juice;

[0011] Step S2: Add pectinase and acid protease to the primary whole-fruit juice obtained in Step S1, perform enzymatic hydrolysis at a temperature of 35-40 °C for 55-65 min, and filter to obtain a juice solution;

[0012] Step S3: Add macroporous adsorption resin to the juice solution obtained in Step S2 for ultrasonic treatment, and filter to obtain a defatted juice;

[0013] Step S4: Add an antioxidant to the defatted juice obtained in Step S3, the addition amount of the antioxidant is 0.1-0.3% (w / w%, mass percentage) of the mass of the defatted juice, sterilize at a temperature of 80 °C for 10-15 min, and fill to obtain the product.

[0014] Further, the conditions for wet ultrafine grinding in Step S1 are: treating for 2-3 min under a microjet pressure of 100-120 MPa.

[0015] Further, the conditions for homogenization in Step S1 are: homogenizing for 4-6 min under a rotation speed of 1000-15000 r / min and a temperature of 25-30 °C.

[0016] Further, in the step S2, the addition amount of pectinase is 0.001 g / mL, and the addition amount of acid protease is 0.003 g / mL.

[0017] Further, in the step S3, the addition amount of macroporous adsorption resin is 2-3% (w / w%, mass percentage) of the mass of the fruit juice liquid, and it is treated for 40-50 min under the condition that the ultrasonic intensity is 8-12 W / cm 2 of.

[0018] Further, the macroporous adsorption resin is a non-polar macroporous adsorption resin, with the model of D4020 and the average pore diameter of 100-105 μm.

[0019] Further, the antioxidant in the step S4 is a stevia polyphenol-multi-porous starch complex, and the preparation method of the stevia polyphenol-multi-porous starch complex is as follows:

[0020] Step A: Dry corn starch at 40-50 °C for 20-30 min, and then place the dried corn starch at 120-140 °C for 2-4 h to obtain pretreated starch;

[0021] Step B: Prepare a starch suspension I with a mass concentration of 5-10% by adding the pretreated starch obtained in Step A to ultrapure water. Then add a complex enzyme to the starch suspension I and carry out enzymatic hydrolysis at pH 4.5-5.0 and temperature 40-50 °C for 10-15 h to obtain multi-porous starch;

[0022] Step C: Prepare a starch suspension II with a mass concentration of 2-4% by adding the multi-porous starch obtained in Step B to ultrapure water. Carry out water bath at 90-95 °C and stirring speed of 800-1000 rpm for 15-20 min, then add a stevia polyphenol solution, and then react at 85-90 °C and stirring speed of 800-1000 rpm for 2-3 h, centrifuge, take the precipitate, and freeze-dry to obtain it.

[0023] Further, the complex enzyme in the step B is composed of α-amylase and glucoamylase mixed in a mass ratio of 2:1, and the addition amount of the complex enzyme is 2-3% (w / w%, mass percentage) of the mass of the starch suspension I.

[0024] Further, the stevia polyphenol solution in the step C is a stevia polyphenol aqueous solution with a concentration of 4-6 mg / mL, and the volume ratio of the stevia polyphenol solution to the starch suspension II is 1:1.

[0025] In addition, the present invention also claims to protect a whole fruit juice beverage of ponkan oranges, which is prepared by the above preparation method of the whole fruit juice beverage of ponkan oranges.

[0026] The inventor's research found that the structure and conformation of pectin are easily affected by the processing process. The change of pectin structure plays an important role in the stability of Gonggan juice particles, and the sterilization treatment is the key factor affecting the enzyme activity and pectin structure stability of Gonggan juice. The inventor explored the change law of pectin structure and its influence on the juice quality during the sterilization process of Gonggan juice through different sterilization temperatures and times, clarified the degradation effect of sterilization treatment on pectin and its influence on the stability of Gonggan juice during the processing of Gonggan, thus solving the problem that the sterilization treatment affects the stability of Gonggan juice.

[0027] In addition, the inventor found during the research process that the bitterness, browning and volatilization of aromatic substances in Gonggan juice seriously affect the quality of Gonggan juice. Among them, naringin and limonin are the two main compounds causing the bitterness of Gonggan juice. At present, there are many methods applied to the debittering treatment of citrus juice, but most of them have an impact on the nutritional components of the juice. For this reason, the inventor consulted a large amount of literature and found that using resin for debittering of citrus juice has a good effect and less impact on nutritional components. After a large number of exploratory experiments, the inventor optimized a macroporous adsorption resin with good debittering effect on the whole fruit juice of Gonggan and basically no impact on the nutritional components of the juice. It can basically adsorb naringin and limonin in Gonggan juice, thus achieving a good debittering effect.

[0028] In addition, the inventor also unexpectedly found that adding ultrasonic treatment with a specific intensity during the adsorption process of the macroporous adsorption resin can increase the absorption of naringin and limonin by the macroporous adsorption resin. The inventor guessed that the preferred 8-12W / cm of the present invention 2 can moderately damage the surface of the resin, which can not only increase the adsorption surface area of the resin, but also expose more resin hydrogen bonds, thereby increasing the adsorption effect of the resin.

[0029] Furthermore, in order to reduce the volatilization of aromatic substances, browning, especially non-enzymatic browning, during the storage of Gonggan juice. The inventor first proposed a new type of antioxidant based on the principles of browning and volatilization of aromatic substances. This antioxidant is prepared by subjecting corn starch to porous denaturation and then adding stevia polyphenols for modification treatment. The obtained stevia polyphenol-porous starch complex has the advantages of strong adsorption, good antioxidant effect and high stability. Specifically, the present invention uses a composite enzyme to modify corn starch, which not only obtains a rich and uniform porous structure, but also exposes more active groups inside the porous starch particles, expands the distribution area of lipophilic groups, and enhances the adsorption effect of porous starch on aromatic substances, thereby reducing the volatilization of aromatic substances in Gonggan juice. At the same time, the stevia polyphenols loaded in the porous starch can further prevent the volatilization and oxidation of aromatic substances, and the two work together to effectively maintain the aromatic substances in Gonggan juice and keep the pure taste of Gonggan juice.

[0030] Furthermore, the present invention adds the stevia polyphenol-porous starch complex to the whole fruit juice of Gonggan oranges. It has been proven by experiments that this polyphenol complex can significantly inhibit the oxidative degradation of vitamin C in the Gonggan orange juice system, inhibit the occurrence of non-enzymatic browning during the storage of Gonggan orange juice, and at the same time, it can also reduce the chemical activity of the reactants in the reaction system of Gonggan orange juice, hinder the development of the Maillard reaction, reduce the further reaction of intermediates to develop into brown substances, and reduce the browning of Gonggan orange juice. At the same time, the stevia polyphenol-loaded porous starch can be released stably and continuously, thus achieving the effect of long-term inhibition of browning.

[0031] In summary, compared with the prior art, the preparation method of the whole fruit juice beverage of Gonggan oranges provided by the present invention has the following advantages:

[0032] (1) The preparation method of the whole fruit juice beverage of Gonggan oranges provided by the present invention is to extract the whole fruit of Gonggan orange raw materials, and use wet ultrafine powder and complex enzyme hydrolysis treatment for tissues such as pulp and peel. Not only is the juice yield high, but also the nutritional components of the whole fruit of Gonggan orange can be fully utilized. The whole fruit juice of Gonggan orange prepared has the advantages of strong Gonggan orange flavor, moderate viscosity, rich taste, and high nutritional components, providing a theoretical basis for the development of high-quality whole fruit juice products of Gonggan orange.

[0033] (2) The preparation method of the whole fruit juice beverage of Gonggan oranges provided by the present invention uses macroporous adsorption resin to remove bitterness and adds a new antioxidant, which can effectively inhibit the phenomena of aggregation, precipitation, stratification, and turbidity during the storage of the whole fruit juice beverage of Gonggan oranges. At the same time, it can also effectively prevent the browning of Gonggan orange juice and the loss of unique aroma components of Gonggan oranges, and has high stability, which can promote the development of the whole fruit juice beverage of Gonggan oranges. Description of the Drawings

[0034] Figure 1 It is a graph showing the influence results of sterilization treatment on the total sugar, reducing sugar, vitamin C, and total acid of the whole fruit juice of Gonggan oranges.

[0035] Figure 2 It is a graph showing the influence results of sterilization treatment on the soluble solids, soluble pectin content, protein, and total phenol content of the whole fruit juice of Gonggan oranges.

[0036] Figure 3 It is a graph showing the influence results of sterilization treatment on the PME enzyme activity of the whole fruit juice of Gonggan oranges.

[0037] Figure 4 It is a graph showing the influence results of sterilization treatment on the turbidity of the whole fruit juice of Gonggan oranges.

[0038] Figure 5 It is a graph showing the sensory changes of the whole fruit juice of Gonggan oranges under sterilization treatment under different conditions. Detailed Embodiments

[0039] The present invention will be further described below through the description of specific embodiments. However, this is not a limitation of the present invention. Those skilled in the art can make various modifications or improvements based on the basic idea of the present invention. As long as they do not depart from the basic idea of the present invention, they are within the scope of the present invention. All materials involved in the present invention are food-grade materials, which are conventional commercially available products.

[0040] I. Exploring the change law of pectin structure during the sterilization process of Gonggan oranges and its influence on the juice quality

[0041] 1. Influence of sterilization treatment on the physicochemical properties of the whole Gonggan orange juice:

[0042] Under the whole Gonggan orange juice system, the whole Gonggan orange juice was sterilized at different temperatures (80, 100, 120 °C), and the physicochemical indexes of the whole Gonggan orange juice were measured: the changes in total sugar, reducing sugar, vitamin C, and total acid. The results are as Figure 1 shown.

[0043] Figure 1 is the result diagram of the influence of sterilization treatment on the total sugar, reducing sugar, vitamin C, and total acid of the whole Gonggan orange juice. Among them: a - total sugar, b - reducing sugar, c - vitamin C, d - total acid. From Figure 1 it can be seen that with the increase of temperature and the prolongation of treatment time, the content of total sugar in the juice increased compared with the untreated group ( Figure 1 a), while the reducing sugar decreased compared with the untreated group ( Figure 1 b). High-temperature treatment had a greater impact on the content of vitamin C. With the prolongation of high-temperature treatment time, the content of vitamin C gradually decreased ( Figure 1 c). At the same time, the content of total acid in the juice was also affected by the sterilization treatment and was lower than that of the untreated group.

[0044] 2. Influence of sterilization treatment on the physicochemical properties of the whole Gonggan orange juice:

[0045] Under the whole Gonggan orange juice system, the whole Gonggan orange juice was sterilized at different temperatures (80, 100, 120 °C), and the changes in soluble solids (TSS), soluble pectin content, protein, and total phenol content in the whole Gonggan orange juice were measured. The results are as Figure 2 shown.

[0046] Figure 2 is the result diagram of the influence of sterilization treatment on the soluble solids, soluble pectin content, protein, and total phenol content of the whole Gonggan orange juice. Among them: a - soluble solids, b - soluble pectin concentration, c - protein concentration, d - total phenol content. From Figure 2 it can be seen that the temperature treatment had little effect on the content of soluble solids in the juice ( Figure 2a). Detection of the soluble pectin content in different treatment groups showed that sterilization treatment could reduce the soluble pectin content in the juice. As the treatment time prolonged, the soluble pectin gradually decreased, and the treatment at 100 °C and 120 °C for 30 min had the greatest impact on the soluble pectin content ( Figure 2 b). Detection of the protein content in different treatment groups showed that high-temperature sterilization treatment significantly reduced the protein content in the juice. As the temperature increased and the treatment time prolonged, the protein in the juice significantly decreased, and the protein content was the lowest after treatment at 120 °C for 30 min, proving that high-temperature long-term sterilization treatment significantly reduced the protein content in the juice. Figure 2 c). Determination of the total phenol content in the treatment groups showed that high-temperature treatment could increase the total phenol content in the juice. The higher the temperature and the longer the treatment time, the higher the total phenol content in the juice. Figure 2 d).

[0047] 3. Influence of sterilization treatment on the stability of whole citrus reticulata blanco juice:

[0048] Under the whole citrus reticulata blanco juice system, the whole citrus reticulata blanco juice was sterilized at different temperatures (80, 100, 120 °C), and the stability indexes were measured, including: pectin methylesterase activity (PME enzyme activity), turbidity, sedimentation index, particle size, viscosity curve. The results are as Figures 3 - 5 shown in and Table 1.

[0049] Table 1 Influence of sterilization treatment on the sediment volume of whole citrus reticulata blanco fruit juice

[0050]

[0051] Figure 3 is the result graph of the influence of sterilization treatment on the PME enzyme activity of whole citrus reticulata blanco fruit juice; Figure 4 is the result graph of the influence of sterilization treatment on the turbidity of whole citrus reticulata blanco fruit juice; Figure 5 is the sensory change graph of whole citrus reticulata blanco fruit juice sterilized under different conditions.

[0052] From Figures 3 - 5 and Table 1, it can be seen that high-temperature sterilization treatment can reduce the activity of PME enzyme. Treating for more than 20 min at 80 °C can inactivate more than 50% of the PME enzyme activity, while treating at 120 °C for 30 min can inactivate more than 80% of the PME enzyme activity. However, treating at 80 °C for 10 min has no obvious effect on the activity of PME enzyme. Figure 3 ). Analysis of turbidity showed that high-temperature sterilization had a certain impact on the turbidity of the juice. Under pasteurization conditions (80 °C), the influence on the turbidity of citrus reticulata blanco juice was not obvious. Treating for 10 - 20 min would not cause sedimentation. However, under high-temperature conditions, the turbidity of citrus reticulata blanco juice was seriously affected after sterilization. Figure 4 ), and at the same time, the sediment volume increased and the sedimentation index rose (Table 1), with obvious large flocculent precipitates.Figure 5 )。

[0053] 4. Influence of sterilization treatment under different conditions on the particle size of whole Citrus reticulata Blanco fruit juice:

[0054] Under the whole Citrus reticulata Blanco fruit juice system, the whole Citrus reticulata Blanco fruit juice was sterilized at different temperatures (80, 100, 120 °C), and the particle size of the whole Citrus reticulata Blanco fruit juice was measured. The results are shown in Table 2.

[0055] Table 2 Changes in the particle size of whole Citrus reticulata Blanco fruit juice under sterilization treatment under different conditions

[0056]

[0057]

[0058] As can be seen from Table 2, with the extension of sterilization time, the particle size first increased and then decreased. Among them, the treatment at 100 °C had the greatest influence on the particle size in the juice, and the treatment at 80 °C had the lowest influence.

[0059] Example 1. Preparation of a steviol polyphenol - porous starch complex

[0060] Step A: The corn starch was dried at 45 °C for 25 min, and then the dried corn starch was placed at 140 °C for 3 h to obtain pretreated starch.

[0061] Step B: The pretreated starch obtained in Step A was mixed with ultrapure water to prepare a starch suspension I with a mass concentration of 6%. Then, a complex enzyme was added to the starch suspension I. The complex enzyme was composed of α - amylase and glucoamylase mixed in a mass ratio of 2:1, and the addition amount of the complex enzyme was 2% (w / w%) of the mass of the starch suspension I. Enzymolysis was carried out at pH 5.0 and a temperature of 45 °C for 12 h to obtain porous starch.

[0062] Step C: The porous starch obtained in Step B was mixed with ultrapure water to prepare a starch suspension II with a mass concentration of 3%. It was bathed at 90 °C with a stirring speed of 1000 rpm for 18 min, and then a steviol polyphenol solution was added. The steviol polyphenol solution was an aqueous solution of steviol polyphenol with a concentration of 5 mg / mL, and the volume ratio of the steviol polyphenol solution to the starch suspension II was 1:1. Then, the reaction was carried out at 85 °C with a stirring speed of 1000 rpm for 2 h, centrifuged, the precipitate was taken, and freeze - dried to obtain the steviol polyphenol - porous starch complex.

[0063] Example 2. Preparation method of a whole Citrus reticulata Blanco fruit juice beverage

[0064] Step S1: Select 500 g of fresh, plump, non-rotten and disease-free Gonggan oranges. After washing, crush them with a juicer to obtain whole fruit pulp. Mix the whole fruit pulp with ultrapure water at a volume ratio of 1:1, and perform wet ultrafine grinding. The conditions for the wet ultrafine grinding are: process for 3 min under the condition that the micro-jet pressure is 120 MPa; homogenize, and the conditions for the homogenization are: homogenize for 5 min under the conditions that the rotation speed is 1200 r / min and the temperature is 30 °C to obtain the initial whole fruit juice;

[0065] Step S2: Add pectinase and acidic protease to the initial whole fruit juice obtained in Step S1. The addition amount of the pectinase is 0.001 g / mL, and the addition amount of the acidic protease is 0.003 g / mL. Enzymatically hydrolyze at a temperature of 40 °C for 60 min, and filter to obtain fruit juice;

[0066] Step S3: Add macroporous adsorption resin to the fruit juice obtained in Step S2 for ultrasonic treatment. The macroporous adsorption resin is D4020 non-polar macroporous adsorption resin with an average pore diameter of 100 - 105 μm. The addition amount of the D4020 macroporous adsorption resin is 3% (w / w%) of the mass of the fruit juice. Treat under the condition that the ultrasonic intensity is 12 W / cm 2 for 40 min, and filter to obtain de-bittered fruit juice;

[0067] Step S4: Add an antioxidant to the de-bittered fruit juice obtained in Step S3. The antioxidant is the stevia polyphenol - porous starch complex prepared in Example 1. The addition amount of the antioxidant is 0.2% (w / w%) of the mass of the de-bittered fruit juice. Sterilize at a temperature of 80 °C for 10 min, and fill to obtain the product.

[0068] Example 3: A preparation method of a whole Gonggan orange juice beverage

[0069] Step S1: Select 500 g of fresh, plump, non-rotten and disease-free Gonggan oranges. After washing, crush them with a juicer to obtain whole fruit pulp. Mix the whole fruit pulp with ultrapure water at a volume ratio of 1:1, and perform wet ultrafine grinding. The conditions for the wet ultrafine grinding are: process for 3 min under the condition that the micro-jet pressure is 100 MPa; homogenize, and the conditions for the homogenization are: homogenize for 4 min under the conditions that the rotation speed is 1500 r / min and the average temperature is 25 °C to obtain the initial whole fruit juice;

[0070] Step S2: Add pectinase and acidic protease to the initial whole fruit juice obtained in Step S1. The addition amount of the pectinase is 0.001 g / mL, and the addition amount of the acidic protease is 0.003 g / mL. Enzymatically hydrolyze at a temperature of 40 °C for 60 min, and filter to obtain fruit juice;

[0071] Step S3: Add macroporous adsorption resin to the fruit juice obtained in Step S2 and perform ultrasonic treatment. The macroporous adsorption resin is D4020 non-polar macroporous adsorption resin with an average pore diameter of 100 - 105 μm. The addition amount of the D4020 macroporous adsorption resin is 2% (w / w%) of the mass of the fruit juice. Treat for 50 min under the condition of ultrasonic intensity of 10 W / cm 2 and then filter to obtain bitter-removed fruit juice;

[0072] Step S4: Add antioxidant to the bitter-removed fruit juice obtained in Step S3. The antioxidant is the stevia polyphenol - porous starch complex prepared in Example 1. The addition amount of the antioxidant is 0.3% (w / w%) of the mass of the bitter-removed fruit juice. Sterilize at 80 °C for 15 min and then fill to obtain the product.

[0073] Comparative Example 1: A preparation method of a whole fruit juice beverage of Gonggan oranges

[0074] The difference from Example 2 is that: the bitter-removing step in Step S3 is: add naringinase solution to the fruit juice obtained in Step S2. In the enzymatic hydrolysis reaction, add naringinase solution containing 1500 - 2000 U of naringinase per liter of fruit juice, and then carry out a constant temperature hydrolysis reaction at 45 °C for 30 min to obtain bitter-removed fruit juice; the remaining steps are similar to those in Example 2.

[0075] Comparative Example 2: A preparation method of a whole fruit juice beverage of Gonggan oranges

[0076] The difference from Example 2 is that: the bitter-removing step in Step S3 is: add macroporous adsorption resin to the fruit juice obtained in Step S2. The macroporous adsorption resin is D4020 non-polar macroporous adsorption resin with an average pore diameter of 100 - 105 μm. The addition amount of the D4020 macroporous adsorption resin is 3% (w / w%) of the mass of the fruit juice. Adsorb at 25 °C for 120 min and then filter to obtain bitter-removed fruit juice; the remaining steps are similar to those in Example 2.

[0077] Comparative Example 3: A preparation method of a whole fruit juice beverage of Gonggan oranges

[0078] The difference from Example 2 is that: the bitter-removing step in Step S3 is: add macroporous adsorption resin to the fruit juice obtained in Step S2. The macroporous adsorption resin is D4020 non-polar macroporous adsorption resin with an average pore diameter of 100 - 105 μm. The addition amount of the D4020 macroporous adsorption resin is 3% (w / w%) of the mass of the fruit juice. Oscillate at 25 °C and a rotation speed of 140 r / min for 90 min and then filter to obtain bitter-removed fruit juice; the remaining steps are similar to those in Example 2.

[0079] Comparative Example 4: A preparation method of a whole fruit juice beverage of Gonggan oranges

[0080] The difference from Example 2 is that the antioxidant in step S4 is epigallocatechin gallate, and the addition amount of the antioxidant is 0.3% (w / w%) of the mass of the debittered juice. The remaining steps are similar to those in Example 2.

[0081] Comparative Example 5, A method for preparing a whole fruit juice beverage of Gonggan tangerine

[0082] The difference from Example 2 is that the antioxidant in step S4 is a composite antioxidant, which is composed of vitamin C, vitamin E, citric acid and tea polyphenols mixed in a mass ratio of 1:1:1:1. The addition amount of the composite antioxidant is 0.3% (w / w%) of the mass of the debittered juice. The remaining steps are similar to those in Example 2.

[0083] Test Example 1, Determination of naringin and limonin contents in the whole fruit juice beverage of Gonggan tangerine

[0084] 1. Test materials:

[0085] The whole fruit juice beverages of Gonggan tangerine prepared in Example 2, Comparative Example 1, Comparative Example 2 and Comparative Example 3.

[0086] 2. Test methods:

[0087] Determine the contents of naringin and limonin in the whole fruit juice beverages of Gonggan tangerine prepared in Example 2, Comparative Example 1, Comparative Example 2 and Comparative Example 3. Among them, naringin was determined by the Davis spectrophotometry, and the specific determination method refers to the paper (Xu Huijue. Study on debittering of Shatian pomelo juice by two lactic acid bacteria [D]. South China University of Technology, 2014). Limonin was determined by high performance liquid chromatography, and the specific determination method refers to the paper (Chen Jing, Gao Yanxiang, Wu Weili, etc. Determination of limonin and naringin in citrus juice by high performance liquid chromatography [J]. Chromatography, 2006, (02): 157-160.).

[0088] 3. Test results

[0089] The test results are shown in Table 3.

[0090] Table 3 Contents of naringin and limonin in the whole fruit juice beverage of Gonggan tangerine

[0091] Naringin (mg / L) Limonin (mg / L) Bitterness threshold 30 3.4 Example 2 9.58 1.22 Comparative Example 1 29.67 3.25 Comparative Example 2 28.34 3.09 Comparative Example 3 20.16 2.10

[0092] As can be seen from Table 3, the contents of naringin and limonin in the whole fruit juice beverage of Gonggan tangerine prepared by the present invention are low, which can effectively reduce the bitterness of the whole fruit juice of Gonggan tangerine and improve the quality of the whole fruit juice beverage of Gonggan tangerine.

[0093] Test Example 2, Determination of the browning degree of the whole fruit juice beverage of Gonggan tangerine

[0094] 1. Test materials:

[0095] The whole fruit juice beverage of Gonggan oranges prepared in Example 2, Comparative Example 4 and Comparative Example 5.

[0096] 2. Test methods:

[0097] Determine the browning degree of the whole fruit juice beverage of Gonggan oranges prepared in Example 2, Comparative Example 4 and Comparative Example 5. After filling the whole fruit juice beverage of Gonggan oranges prepared in Example 2, Comparative Example 4 and Comparative Example 5 and placing it at room temperature for 6 months, determine the browning degree of the whole fruit juice beverage of Gonggan oranges at the 1st month, 2nd month, 3rd month and 6th month. Use the debittered juice without antioxidant prepared in step S3 of Example 2 as the control group. The browning degree is characterized by the absorbance value of the whole fruit juice beverage of Gonggan oranges at 420 nm. Dilute the sample with distilled water to 11.5 Brix and place it in a 1 cm cell, and then measure its absorbance at 420 nm using an ultraviolet-visible spectrophotometer.

[0098] 3. Test results:

[0099] The test results are shown in Table 4.

[0100] Table 4 Browning degree of the whole fruit juice beverage of Gonggan oranges

[0101]

[0102] As can be seen from Table 4, the whole fruit juice beverage of Gonggan oranges prepared by the present invention has a lower browning degree after being placed at room temperature for 6 months, has higher stability, and can effectively improve the quality of the whole fruit juice beverage of Gonggan oranges.

[0103] Test Example III. Determination of the content of aromatic substances in the whole fruit juice beverage of Gonggan oranges

[0104] 1. Test materials:

[0105] The whole fruit juice beverage of Gonggan oranges prepared in Example 2, Comparative Example 4 and Comparative Example 5.

[0106] 2. Test methods:

[0107] Determine the contents of the main flavor substances in the whole fruit juice beverage of Gonggan oranges prepared in Example 2, Comparative Example 4 and Comparative Example 5: E-2-hexenal, linalool, Z-linalool oxide and E-linalool oxide. After filling the whole fruit juice beverage of Gonggan oranges prepared in Example 2, Comparative Example 4 and Comparative Example 5 and placing it at room temperature for 60 days, determine the contents of the main flavor substances in the whole fruit juice beverage of Gonggan oranges on the 1st day, 30th day and 60th day.

[0108] 3. Test results:

[0109] The test results are shown in Table 5.

[0110] Table 5 Flavor Substance Contents in Whole Fruit Juice Beverage of Gonggan Oranges (Day 1)

[0111]

[0112]

[0113] As can be seen from Table 5, the whole fruit juice beverage of Gonggan oranges prepared by the present invention has high stability, can reduce the dissipation of important flavors such as E-2-hexenal, linalool, Z-linalool oxide and E-linalool oxide, maintain the unique flavor of the whole fruit juice of Gonggan oranges, and improve the taste of the whole fruit juice beverage of Gonggan oranges.

[0114] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A preparation method of a whole fruit juice beverage of Gonggan oranges, characterized in that, It includes the following steps: Step S1: Wash and crush the Gonggan oranges to obtain whole fruit pulp. Mix the whole fruit pulp with ultrapure water at a volume ratio of 1:1, perform wet ultrafine grinding treatment, and homogenize to obtain the initial whole fruit juice; Step S2: Add pectinase and acidic protease to the initial whole fruit juice obtained in Step S1, enzymatically hydrolyze at a temperature of 35 - 40°C for 55 - 65 min, and filter to obtain the fruit juice; Step S3: Add macroporous adsorption resin to the fruit juice obtained in Step S2 for ultrasonic treatment, and filter to obtain the de - bittered fruit juice; Step S4: Add an antioxidant to the de - bittered fruit juice obtained in Step S3. The addition amount of the antioxidant is 0.1 - 0.3% of the mass of the de - bittered fruit juice. Sterilize at a temperature of 80°C for 10 - 15 min, and fill into containers to obtain the product.

2. The preparation method of the whole fruit juice beverage of Gonggan oranges according to claim 1, characterized in that, The conditions for wet ultrafine grinding in Step S1 are: treat under a micro - jet pressure of 100 - 120 MPa for 2 - 3 min.

3. The preparation method of the whole fruit juice beverage of Gonggan oranges according to claim 1, characterized in that, The conditions for homogenization in Step S1 are: homogenize at a rotation speed of 1000 - 15000 r / min and a temperature of 25 - 30°C for 4 - 6 min.

4. The preparation method of the whole fruit juice beverage of ponkan oranges as claimed in claim 1, characterized in that, In Step S2, the addition amount of pectinase is 0.001 g / mL, and the addition amount of acidic protease is 0.003 g / mL.

5. The preparation method of the whole fruit juice beverage of Gonggan oranges according to claim 1, characterized in that, The addition amount of the macroporous adsorption resin in the step S3 is 2-3% of the mass of the fruit juice solution, and it is treated for 40-50 min under the condition that the ultrasonic intensity is 8-12 W / cm 2 .

6. The preparation method of the whole fruit juice beverage of Gonggan as claimed in claim 5, characterized in that, The macroporous adsorption resin is a non - polar macroporous adsorption resin, with the model D4020 and an average pore diameter of 100 - 105 μm.

7. The preparation method of the ponkan whole fruit juice beverage according to claim 1, characterized in that, The antioxidant in Step S4 is a stevia polyphenol - porous starch complex. The preparation method of the stevia polyphenol - porous starch complex is as follows: Step A: Dry corn starch at 40 - 50°C for 20 - 30 min, and then place the dried corn starch at a temperature of 120 - 140°C for 2 - 4 h to obtain the pretreated starch; Step B: Prepare a starch suspension I with a mass concentration of 5 - 10% by adding ultrapure water to the pretreated starch obtained in Step A. Then add a complex enzyme to the starch suspension I, and enzymatically hydrolyze at a pH of 4.5 - 5.0 and a temperature of 40 - 50°C for 10 - 15 h to obtain porous starch; Step C: Prepare a starch suspension II with a mass concentration of 2 - 4% by adding ultrapure water to the porous starch obtained in Step B. Perform a water bath at a temperature of 90 - 95°C and a stirring speed of 800 - 1000 rpm for 15 - 20 min, then add the stevia polyphenol solution, and then react at a temperature of 85 - 90°C and a stirring speed of 800 - 1000 rpm for 2 - 3 h. Centrifuge, take the precipitate, and freeze - dry to obtain the product.

8. The preparation method of the whole fruit juice beverage of Gonggan oranges according to claim 7, characterized in that, The complex enzyme in Step B is composed of α - amylase and glucoamylase mixed at a mass ratio of 2:1, and the addition amount of the complex enzyme is 2 - 3% of the mass of the starch suspension I.

9. The preparation method of the whole fruit juice beverage of Gonggan oranges according to claim 7, characterized in that, The stevia polyphenol solution in Step C is a 4 - 6 mg / mL stevia polyphenol aqueous solution, and the volume ratio of the stevia polyphenol solution to the starch suspension II is 1:

1.

10. A whole fruit juice beverage of Gonggan oranges, characterized in that, Prepared by the preparation method of the Gonggan whole fruit juice beverage according to any one of Claims 1 - 9.

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