Method for preparing sugar-reduced high-methoxyl pectin gel by using sucrose substitute composition

Abstract

The invention discloses a method for preparing sugar-reduced high-methoxyl pectin gel by using a sucrose substitute composition, and belongs to the field of preparation of high-methoxyl pectin gel. The sugar-reduced high-methoxyl pectin gel is prepared from the following components in parts by mass: 0.3 to 0.5 part of high-methoxyl pectin powder, 20 to 30 parts of sucrose substitute composition, 0.1 to 0.3 part of edible acid, 0.01 to 0.02 part of calcium lactate and 1 to 5 parts of water. Compared with an existing high-methoxyl pectin sugar reducing method, the sucrose replacement composition is designed, the momordica grosvenori syrup, the maltitol and the xylitol are compounded for sugar reduction, sucrose can be replaced by 100% at most, the glycemic index of gel is reduced by 60%-70%, and the content of the high-methoxyl pectin is reduced. Meanwhile, the structure of maltitol is utilized to exert the original gelling promoting effect of cane sugar and is combined with the gelling effect of calcium lactate, so that the gel property of the pectin gel after sugar reduction is not obviously different from that of sensory evaluation and is also improved, and the preparation method of the low-sugar high-methoxyl pectin capable of reducing sugar and not reducing quality is realized.

Description

Technical Field

[0001] The invention relates to a method for preparing reduced-sugar high-methoxy pectin gel by utilizing a sucrose replacement composition, and belongs to the field of high-methoxy pectin gel preparation. Background Art

[0002] Pectin is the main component of plant cell walls and is divided into high methoxy pectin and low methoxy pectin. The degree of carboxyl esterification of pectin molecules is usually called pectin esterification degree (DE). According to the different esterification degrees of pectin, it is divided into high methoxy pectin (HMP, DE>50%) and low methoxy pectin (LMP, DE<50%).

[0003] When high methoxy pectin is used to prepare pectin gel, high methoxy pectin and high concentration of sucrose need to be prepared under high temperature and acidic environment to obtain high methoxy pectin gel. High methoxy pectin gel plays an important role in the processing of fruit and vegetable processed products. However, under normal circumstances, 55wt% or more sucrose is required in the high methoxy pectin pectin gel system to meet the formation of pectin gel, but this means that high methoxy pectin gel is a high-sugar product. This high-sugar product is not suitable for infants and special groups, and does not conform to the healthy diet concept of "low sugar and zero calories", and the consumer group is relatively limited. Choerospondias australis pectin is a high methoxy pectin, so the choerospondias australis pectin gel prepared by traditional methods has the problem of too high sucrose content, which does not meet the needs of modern consumption. Therefore, the problem of traditional choerospondias australis pectin gel needs to be solved by reducing the addition of sucrose and maintaining the edible quality of choerospondias australis pectin gel.

[0004] In the preparation of high methoxyl pectin gel, the main function of sucrose (dehydrating agent) is to react with pectin (adhesive) at high temperature under the acidic conditions of the fruit pulp itself to form pectin gel. For high methoxyl pectin, sucrose adds additional hydrophilic substituents during the gel formation process to snatch water molecules bound to pectin molecules. The pectin chains that lose water molecules will approach each other under the hydrophobic interaction of the ester group, promoting the aggregation and hydrophobic association between pectin molecular chains. If the sucrose concentration is low, it cannot provide enough hydrophilic groups for the association of pectin molecules, and pectin gel cannot be formed. Therefore, according to the mechanism of action of sucrose in the formation of pectin gel, sugar alcohols similar to sucrose in molecular structure and hydrophilic properties can be selected to replace sucrose. Although sugar alcohols are similar to sucrose in sweetness, they have a lower glycemic index. In addition, the molecular structure of sugar alcohols also has hydroxyl and primary hydroxyl groups similar to those in sucrose molecules. Therefore, replacing sucrose with sugar alcohols can not only reduce the calorific value of gel but also promote the formation of pectin gel. However, the specific coagulation-promoting effect still needs further exploration. Directly replacing sucrose with sugar alcohol will lead to poor gelling effect of pectin gel to a certain extent, and the hardness and chewiness of the gel will decrease.

[0005] At present, in the prior art, CN102885271A uses xylitol, maltitol and erythritol to reduce sucrose, and successfully reduces the total sugar content of the product to less than 5%. However, it prepares a low-sugar Chinese jujube cake, not a Chinese jujube pectin gel, and CN102885271A solves the problems of sugar reduction and crystallization and sand return, and does not involve the gelation problem of pectin gel or even the gel quality problem. Therefore, the sugar reduction process for high methoxyl pectin gel still needs to be studied. Summary of the invention

[0006] Technical issues

[0007] At present, the mainstream sugar reduction method is to simply reduce the addition of sucrose and promote the formation of gel by adding additional colloids, but the sugar reduction effect of this method is limited and it is impossible to achieve zero sucrose addition. At the same time, simply using a single sugar alcohol or a combination of disaccharide alcohols to replace sucrose, although the amount of sucrose can be reduced by more than 90%, the difference in sweetness and coagulation effect between sugar alcohols and sucrose will cause the sensory perception of the gel to deteriorate and the gel properties to be poor. Therefore, in-depth research is needed on sugar-reduced gels of high methoxyl pectin to provide a method for preparing high methoxyl pectin that reduces sugar without reducing the quality of the gel.

[0008] Technical Solution

[0009] The present invention uses a composite replacement composition of monk fruit syrup, maltitol and xylitol to replace sucrose. The monk fruit syrup is rich in natural sweetener mogroside, which solves the problem of sweetness loss caused by sucrose reduction. Maltitol and xylitol have similar hydroxyl structures to sucrose and can effectively play a coagulation-promoting role. However, since the coagulation-promoting ability of sugar alcohols is not as good as that of sucrose, the gel properties of the gel sample are not good after a large amount of sugar alcohols replace sucrose. In order to achieve the effect of reducing sugar without changing the basic form and taste of pectin gel, calcium ions are introduced into the system by adding calcium lactate according to the "GB 2760-2014 Food Additives Use Standard" to promote the formation of pectin gel. Calcium ions will non-covalently bind to pectin chains to reduce the electrostatic interaction between pectin chains. The formed pectin-calcium gel system will reduce the demand for soluble solids, and the addition of sugar can be further reduced. The prepared reduced-sugar pectin gel is not much different from pure sucrose gel in sweetness and sensory perception, and the gel properties meet the requirements.

[0010] In order to achieve the above invention objectives, the present invention provides a reduced-sugar high-methoxy pectin gel, which contains, by mass, 0.3-0.5 parts of high-methoxy pectin powder, 20-30 parts of sucrose replacement composition, 0.1-0.3 parts of edible acid, 0.01-0.02 parts of calcium lactate and 1-5 parts of water.

[0011] Furthermore, the sucrose replacement composition is composed of the following raw materials by mass fraction: 20-60% monk fruit syrup, 30-60% maltitol, 10-15% xylitol, and 0-10% sucrose.

[0012] Furthermore, the sucrose replacement composition is composed of the following raw materials by mass fraction: 20-50% monk fruit syrup, 30-50% maltitol, 10-15% xylitol, and 0-10% sucrose.

[0013] Furthermore, the sucrose replacement composition is composed of the following raw materials by mass fraction: 40-50% monk fruit syrup, 30-40% maltitol, 10-15% xylitol, and 0-10% sucrose.

[0014] Furthermore, the high methoxyl pectin powder includes axillaris pectin powder, high ester citrus pectin powder or high ester apple pectin powder.

[0015] Furthermore, high methoxyl pectin refers to pectin with a degree of esterification (DE value, the degree of esterification of the carboxyl groups of the pectin molecule) greater than 50%.

[0016] Furthermore, the preparation method of the high methoxy pectin powder includes: pulp or peel rich in high methoxy pectin (pectin content ≥1%) and water in a mass ratio of 1:2 to 8 to obtain a slurry, then adjusting the pH value of the slurry to 1.5 to 2.5, then cooking at 80 to 95° C. for 60 to 120 minutes, then centrifuging, retaining the supernatant, mixing the supernatant with ethanol, then filtering to obtain a precipitate, and drying the precipitate to obtain the high methoxy pectin powder.

[0017] Furthermore, the pulp or peel rich in high methoxyl pectin includes sour jujube, citrus, apple, citrus peel or apple peel.

[0018] Furthermore, the edible acid includes one or more of citric acid, malic acid, and gluconic acid.

[0019] The present invention also provides a method for preparing a reduced-sugar high-methoxyl pectin gel using a sucrose replacement composition, the method comprising the following steps:

[0020] (1) mixing high methoxyl pectin powder with water, stirring to dissolve the pectin powder to obtain a pectin solution;

[0021] (2) adding edible acid and calcium lactate to the pectin solution obtained in step (1) and stirring, then adding the sucrose replacement composition, then adjusting the pH value of the solution to 2-3, and heating and stirring;

[0022] (3) pouring the pectin solution after heating and stirring in step (2) into a mold and storing it in a refrigerator to obtain a sugar-reduced high-methoxyl pectin gel.

[0023] Furthermore, in the method, in step (1), the mass ratio of high methoxy pectin powder to water is 0.3-0.5:1-5.

[0024] Furthermore, in the method, in step (2), the mass ratio of high methoxy pectin powder to edible acid is 0.3-0.5:0.1-0.3.

[0025] Furthermore, in the method, in step (2), the mass ratio of high methoxy pectin powder to calcium lactate is 0.3-0.5:0.01-0.02.

[0026] Furthermore, in the method, in step (2), the mass ratio of high methoxyl pectin powder to sucrose replacement composition is 0.3-0.5:20-30.

[0027] Furthermore, in the method, the sucrose replacement composition is composed of the following raw materials by mass fraction: 20-60% monk fruit syrup, 30-60% maltitol, 10-15% xylitol, and 0-10% sucrose.

[0028] Furthermore, in the method, the sucrose replacement composition is composed of the following raw materials by mass fraction: 20-50% monk fruit syrup, 30-50% maltitol, 10-15% xylitol, and 0-10% sucrose.

[0029] Furthermore, in the method, the sucrose replacement composition is composed of the following raw materials by mass fraction: 40-50% monk fruit syrup, 30-40% maltitol, 10-15% xylitol, and 0-10% sucrose.

[0030] Furthermore, in the method, the stirring temperature in steps (1) and (2) is 50 to 70°C.

[0031] Furthermore, in the method, the stirring time in steps (1) and (2) is 1 to 10 minutes.

[0032] Furthermore, in the method, the pH value of the solution in step (2) is adjusted using a 0.1-0.2 M HCl solution.

[0033] Furthermore, in the method, the temperature of heating and stirring in step (2) is 80-85°C.

[0034] Furthermore, in the method, the heating and stirring time in step (2) is 5 to 15 minutes.

[0035] Furthermore, in the method, the pH value of the solution in step (2) is adjusted to 2.2 to 2.5.

[0036] Furthermore, in the method, the temperature of the refrigerated storage in step (3) is 0 to 5°C.

[0037] Furthermore, in the method, the refrigerated storage time in step (3) is 5 to 15 hours.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] Compared with the existing high-methoxyl pectin sugar reduction method, the present invention designs a sucrose replacement composition, in which monk fruit syrup, maltitol and xylitol are used in combination for sugar reduction, which can replace sucrose by up to 100% and reduce the glycemic index of the gel by 60% to 70%. At the same time, the structure of maltitol is used to exert the original gelation-promoting effect of sucrose and combine with the gelling effect of calcium lactate, so that the gel properties and sensory evaluation of the pectin gel after sugar reduction have no obvious difference and are even improved, thereby realizing a low-sugar high-methoxy pectin preparation method with sugar reduction without quality loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 The present invention is a schematic diagram of the process flow for preparing the sugar-reduced Choerospondias axillaris pectin gel.

[0041] Figure 2 It is a comparison chart of the gel modulus of the embodiment of the present invention and the comparative example. DETAILED DESCRIPTION

[0042] The following is an explanation of the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied by other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, in the absence of conflict, the features in the following embodiments and embodiments can be combined with each other. The raw materials, equipment, and methods used in the present invention, unless otherwise specified, are all commonly used raw materials, equipment, or methods in the art.

[0043] Source of raw materials

[0044] The axillaris pectin powder was extracted from the axillaris provided by Jiangxi Qiyunshan Food Co., Ltd. by using the alcohol extraction method and the acid extraction method, specifically: the axillaris pulp and water mass ratio of 1:5 were blended to obtain a slurry, and then the pH value of the slurry was adjusted to about 2.0 with a 1 mol / L HCl solution, and then the slurry was cooked at 90°C for 90 minutes, and then centrifuged at 4000 rad / s, the supernatant was retained, and the supernatant was mixed with twice the volume of anhydrous ethanol, stirred, and filtered to obtain a flocculent precipitate after standing for 24 hours, and dried to obtain the axillaris pectin powder.

[0045] Maltitol comes from Jiangsu Changjing Bioengineering Co., Ltd.; erythritol comes from Jiangsu Changjing Bioengineering Co., Ltd.; xylitol comes from Jiangsu Changjing Bioengineering Co., Ltd.; monk fruit syrup (main ingredient: erythritol content 30wt%) comes from Yangling Ruifen Biotechnology Co., Ltd.; sucrose comes from Shanghai Sinopharm Group Biological Preparation Co., Ltd.; calcium lactate comes from Shanghai Sinopharm Group Biological Preparation Co., Ltd.; other raw materials are all commonly available on the market unless otherwise specified.

[0046] Table 1 Comparison of sugar alcohol and sucrose

[0047]

[0048]

[0049] Evaluation Method

[0050] 1. The hardness, chewiness and sensory scoring indexes of the pure sucrose sample and the gel prepared by the present invention were measured three times in parallel using a texture analyzer and a sensory evaluation. The gel sample was sensory evaluated and scored according to the sensory evaluation table.

[0051] Table 2 Sensory evaluation table of gel samples

[0052]

[0053] 2. Sample TPA analysis: Place the prepared gel on a physical property analyzer and perform TPA analysis at room temperature 25°C. Instrument parameter settings: test probe P / 0.5R, operation mode TPA analysis, test speed 2.0 mm / s, rebound speed 2.0 mm / s, trigger point load 5.0 g, compression 25%, and measure the hardness and chewiness of the sample.

[0054] 3. Use a rheometer to perform static rheological analysis on the gel to evaluate the gel effect. Specifically: Place the prepared gel on the platform of the rheometer and measure it at room temperature 25°C. Test the flat plate PP40. First, at a fixed angular frequency, measure the compression ratio in the viscoelastic range within the index change range of 0.01 to 100%. Control the angular frequency index change range of 0.1 to 100 rad / s within the measured viscoelastic range. Measure after the sample is stable for 10 seconds. Measure the same measurement point five times to obtain the size of the storage modulus and loss modulus of the sample and the change in the loss factor.

[0055] Example 1

[0056] The sucrose replacement composition comprises: 12 g of monk fruit syrup; 9 g of maltitol; 3.6 g of xylitol; and 1.8 g of sucrose.

[0057] Take 0.48g of Choerospondias australis pectin powder and mix it with 3.2g of deionized water, put it into a water bath and stir it at a constant temperature of 60°C to dissolve the pectin powder to obtain a pectin solution, then add 0.1g of citric acid granules and 0.012g of calcium lactate powder and stir, then adjust the temperature to 80°C, add 26.4g of sucrose substitute composition, use 0.1M HCl solution to adjust the pH value of the solution to 2.3, heat it at a constant temperature of 80°C for 10min, then pour the heated pectin solution into a mold, cool it naturally to room temperature, and store it at 4°C for 12h to obtain reduced-sugar Choerospondias australis pectin gel.

[0058] Example 2

[0059] The sucrose replacement composition comprises: 12 g of monk fruit syrup; 9 g of maltitol; and 3.6 g of xylitol.

[0060] Take 0.48g of Choerospondias australis pectin powder and mix it with 5g of deionized water, put it into a water bath and stir it at a constant temperature of 60°C to dissolve the pectin to obtain a pectin solution, then add 0.1g of citric acid granules and 0.012g of calcium lactate powder and stir, then adjust the temperature to 80°C, add 24.6g of sucrose substitute composition, use 0.1M HCl solution to adjust the pH value of the solution to 2.3, heat it at a constant temperature of 80°C for 10min, then pour the heated pectin solution into a mold, cool it naturally to room temperature, and store it at 4°C for 12h to obtain reduced-sugar Choerospondias australis pectin gel.

[0061] Example 3

[0062] Referring to Example 1, the axillaris pectin powder was replaced with high-ester citrus pectin powder, and the sugar-reduced citrus pectin gel was prepared according to the method of Example 1.

[0063] Preparation process of high ester citrus pectin powder:

[0064] The citrus peel and water are mixed in a mass ratio of 1:5 to obtain a slurry, and then the pH value of the slurry is adjusted to about 2.0 with 1 mol / L HCl solution. The slurry is then cooked at 90°C for 90 minutes, and then centrifuged at 4000 rad / s. The supernatant is retained, mixed with twice the volume of anhydrous ethanol, and allowed to stand for 24 hours. The precipitate is filtered to obtain a flocculent precipitate, which is dried to obtain pectin powder.

[0065] Comparative Example 1

[0066] The calcium lactate powder in Example 1 was omitted, and the sucrose replacement composition in Example 1 was replaced with 18 g sucrose and 8.4 g deionized water. The other parts were the same as in Example 1 to prepare a traditional Choerospondias australis pectin gel as a control. The obtained traditional high methoxy pectin gel was tested to have a DE value of about 61%, which can be used as a representative pectin of high methoxy pectin.

[0067] Comparative Example 2

[0068] The use of the sucrose replacement composition in Example 1 was omitted, and the other steps were the same as in Example 1 to obtain a Choerospondias axillaris pectin gel.

[0069] Comparative Example 3

[0070] The calcium lactate powder in Example 1 was omitted, and the other steps were the same as in Example 1 to obtain the Choerospondias axillaris pectin gel.

[0071] Comparative Example 4

[0072] The amount of calcium lactate added in Example 1 was doubled, and the other contents were kept the same as in Example 1 to obtain Choerospondias axillaris pectin gel.

[0073] Comparative Example 5

[0074] The monk fruit syrup in Example 1 was replaced with an erythritol solution of the same mass (the mass fraction of erythritol in the solution was 30%), and the rest was the same as in Example 1.

[0075] Comparative Example 6

[0076] The method was carried out with reference to Example 1, wherein the sucrose replacement composition was adjusted to: 12 g of monk fruit syrup; 3.6 g of maltitol; and 9 g of xylitol.

[0077] Comparative Example 7

[0078] The method was carried out with reference to Example 1, wherein the sucrose replacement composition was adjusted to: 18 g monk fruit syrup; 3.6 g maltitol; and 3.6 g xylitol.

[0079] Comparative Example 8

[0080] The citric acid particles in Example 1 were omitted, and the other steps were the same as in Example 1 to obtain the Choerospondias axillaris pectin gel.

[0081] Comparative Example 9

[0082] The step of adjusting the pH value of the solution in Example 1 was omitted, and the other steps were consistent with Example 1 to obtain the Choerospondias axillaris pectin gel.

[0083] Comparative Example 10

[0084] The constant temperature heating temperature of the mixture in Example 1 was changed to 50° C., and the other conditions were kept the same as in Example 1 to obtain Choerospondias axillaris pectin gel.

[0085] Comparative Example 11

[0086] The refrigerated storage step in Example 1 was omitted, and the other steps were the same as in Example 1 to obtain the Choerospondias axillaris pectin gel.

[0087] Comparative Example 12

[0088] The calcium lactate powder in Example 1 was omitted, and the sucrose replacement composition in Example 1 was replaced with 9 g of maltitol, 9 g of sucrose and 8.4 g of deionized water. The rest was the same as in Example 1.

[0089] Comparative Example 13

[0090] The calcium lactate powder in Example 1 was omitted, and the sucrose replacement composition in Example 1 was replaced with 9 g of xylitol, 9 g of sucrose and 8.4 g of deionized water. The rest was the same as in Example 1.

[0091] Comparative Example 14

[0092] The calcium lactate powder in Example 1 was omitted, and the sucrose replacement composition in Example 1 was replaced with 9 g of erythritol, 9 g of sucrose and 8.4 g of deionized water. The rest was the same as in Example 1.

[0093] Comparative Example 15

[0094] The calcium lactate powder in Example 3 was omitted, and the other steps were the same as in Example 3 to obtain pectin gel.

[0095] The Choerospondias axillaris pectin gel obtained in the above examples and comparative examples was tested, and the gel sensory test results are shown in Table 3, and the hardness and chewiness test results are shown in Table 4. Comparative Example 1 in the present invention is a control group, which is a pure sucrose sample without additives, that is, a traditional high methoxyl pectin gel.

[0096] Table 3 Test data of Examples 1 to 3 and Comparative Examples 1 to 15

[0097]

[0098] Note: Different letters in the table represent significant differences between the data.

[0099] Table 4 Test data of Examples 1 to 3 and Comparative Examples 1 to 15

[0100]

[0101]

[0102] Note: Different letters in the table represent significant differences between the data.

[0103] 1. In comparative example 2, no sucrose or sugar alcohol was added, and only calcium lactate was added. It was found that the final "pectin gel" could not actually be called a gel, and its composite modulus was very low and the whole was very loose. This is because Ca 2+ The role of the pectin system is to introduce divalent metal cations Ca 2+After that, a strong electrostatic interaction will occur between the metal cation and the negatively charged carboxyl group on the side chain of the pectin molecule. 2+ It will randomly combine with negatively charged free carboxyl groups on the polymer (the same molecule or different molecules) to make the composite polymer tend to be electrically neutral as a whole, reduce electrostatic repulsion and promote aggregation. 2+ The coagulation-promoting effect will make the spatial distance between the methyl ester groups closer, further promote the hydrophobic interaction between polymers, and promote the entanglement between pectin molecules and the formation of a three-dimensional network structure. This effect is common in low methoxyl pectin (LMP) systems, because LMP has a large content of free carboxyl groups and a large number of charged side chains, and the gelation process does not require high sugar and high temperature acidic conditions. Ca 2+ The accelerating coagulation effect can be effectively exerted at a relatively low temperature, such as the technical solution described in patent CN 118652445 A.

[0104] However, for high methoxyl pectin (HMP), high sugar and high temperature acidic conditions are the basic conditions for pectin gel formation. 2+ After mixing, the Zeta potential of the solution did not change significantly and the turbidity did not change much, indicating that the pectin molecules and Ca 2+ Without effective binding, there is no effective aggregation between pectin molecules. Under high sugar concentration conditions, HMP molecules can dehydrate and aggregate to reduce the molecular distance to a certain distance. At this time, Ca 2+ It can effectively play a promoting coagulant role.

[0105] So for HMP, just like the effect in Examples 1 and 2, Ca 2+ It can only play an effective role in accelerating coagulation under the conditions of high sugar, high temperature and acidity. At the same time, calcium lactate can be used as a thickener for candied fruits in the "GB 2760-2014 Food Additives Usage Standard", which can further reduce the addition of soluble solids while improving the properties of pectin gel.

[0106] 2. In Comparative Example 3, after using a sucrose replacement composition to replace sucrose and not adding calcium lactate, it was found by comparison that the hardness and chewiness of Comparative Example 3 were less than those of Example 1, and also less than those of Comparative Example 1. It is explained that it is not feasible to simply replace sucrose in traditional Chinese jujube pectin gel with low-calorie sugar alcohols, which will lead to a decrease in the quality of Chinese jujube pectin gel. This is because in the preparation of high methoxyl pectin gel, sucrose is used as a dehydrating agent, and its hydrophilic substituents rob water molecules bound to pectin molecules. The pectin chains that lose water molecules will approach each other under the hydrophobic interaction of the ester group, promoting the aggregation and hydrophobic association between pectin molecular chains. Although the sugar alcohols used to replace sucrose also have hydrophilic groups similar to those in sucrose molecules, their hydrophilic ability is obviously not as good as sucrose.

[0107] Combining Comparative Examples 1 to 3 with Example 1, it can be seen that if a reduced-sugar Chinese jujube pectin gel is to be prepared, simply omitting the use of sucrose or simply using sugar alcohol instead of sucrose will reduce the quality of the Chinese jujube pectin gel, so the above method cannot be used as a method for reducing the sugar content of Chinese jujube pectin gel. When sugar alcohol is used in place of the composition and calcium lactate, a better effect can be achieved, and a synergistic effect is generated, that is, sugar reduction is achieved while maintaining the quality of the Chinese jujube pectin gel.

[0108] 3. After increasing the amount of calcium lactate added in Comparative Example 4, it was found that the hardness and chewiness of the jujube pectin gel decreased. This is because the increase in calcium lactate concentration will increase the ionic strength in the system, which is not conducive to the construction of the gel network under specific pH conditions, indicating that there is an optimal range for the amount of calcium lactate added.

[0109] 4. In Comparative Example 5, the monk fruit syrup was replaced with an erythritol solution of the same mass concentration. Since the main components of the monk fruit syrup are 30wt% erythritol and 70wt% water, there is no obvious difference in gel performance between the two. However, the sweetener monk fruit glycoside in the monk fruit syrup is missing, so the taste of Comparative Example 5 is not as good as that of Example 1.

[0110] 5. After adjusting the dosage ratio of maltitol, xylitol and erythritol in Comparative Examples 6 and 7, it was found that different ratios of sucrose replacement compositions had different effects. After reducing the addition of maltitol and increasing the dosage of xylitol or erythritol, the gel texture was not good. Further, through the difference between Comparative Examples 12, 13 and 14 and Comparative Example 1, it can be seen that although erythritol (the main component in monk fruit syrup) and xylitol both have primary hydroxyl groups, their coagulation-promoting effects are obviously not as good as maltitol, especially in Comparative Example 14, erythritol also showed serious sanding phenomenon, resulting in poor gel sensory perception. Therefore, in order to improve the edible quality of southern jujube pectin gel, maltitol in the sucrose replacement composition needs to account for a sufficient proportion, at least more than 30wt%.

[0111] 6. Comparative Examples 8, 9 and 10 show that the construction of the gel network of Choerospondias australis must be in a suitable high-temperature acidic environment. Comparative Example 11 shows that refrigeration treatment can strengthen the gel network of Choerospondias australis because low-temperature storage conditions are more conducive to the formation of hydrogen bonds between system molecules.

[0112] 7. It can be seen from Example 3 and Comparative Example 15 that this method is also applicable to citrus pectin gel prepared from high-ester citrus pectin powder, indicating that the method of the present invention is universal in high methoxyl pectin and is not limited to Choerospondias australis pectin.

[0113] In summary, the data show that it is feasible to prepare reduced-sugar high-methoxy pectin gel using a sucrose replacement composition prepared with monk fruit syrup, maltitol and xylitol; at the same time, the addition of calcium lactate can increase the hardness and chewiness of the gel, improve the quality of the gel, achieve a synergistic effect, and maintain the quality of the high-methoxy pectin gel while reducing the use of sucrose in the high-methoxy pectin gel.

[0114] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the definition of the claims.

Claims

1. A reduced-sugar high-methoxyl pectin gel, characterized in that: The reduced-sugar high-methoxy pectin gel contains, by weight, 0.3 to 0.5 parts of high-methoxy pectin powder, 20 to 30 parts of a sucrose replacement composition, 0.1 to 0.3 parts of an edible acid, 0.01 to 0.02 parts of calcium lactate, and 1 to 5 parts of water; The sucrose replacement composition is composed of the following raw materials by mass fraction: 20-60% of monk fruit syrup, 30-60% of maltitol, 10-15% of xylitol, and 0-10% of sucrose.

2. The reduced-sugar high-methoxyl pectin gel according to claim 1, characterized in that: The sucrose replacement composition is composed of the following raw materials by mass fraction: 20-50% monk fruit syrup, 30-50% maltitol, 10-15% xylitol and 0-10% sucrose.

3. The reduced-sugar high-methoxyl pectin gel according to claim 1, characterized in that: The high methoxyl pectin powder includes aconite pectin powder, high ester citrus pectin powder or high ester apple pectin powder.

4. The reduced-sugar high-methoxyl pectin gel according to claim 3, characterized in that: The preparation method of high methoxy pectin powder comprises: beating and mixing pulp or peel rich in high methoxy pectin with water at a mass ratio of 1:2 to 8 to obtain a slurry, then adjusting the pH value of the slurry to 1.5 to 2.5, then steaming at 80 to 95° C. for 60 to 120 minutes, then centrifuging, retaining the supernatant, mixing the supernatant with ethanol, then filtering to obtain a precipitate, and drying the precipitate to obtain the high methoxy pectin powder.

5. The reduced-sugar high-methoxyl pectin gel according to claim 1, characterized in that: The edible acid includes one or more of citric acid, malic acid, and gluconic acid.

6. A method for preparing the reduced-sugar high-methoxyl pectin gel according to any one of claims 1 to 5 using a sucrose replacement composition, characterized in that: The method comprises the following steps: (1) mixing high methoxyl pectin powder with water, stirring to dissolve the pectin powder to obtain a pectin solution; (2) adding edible acid and calcium lactate to the pectin solution obtained in step (1) and stirring, then adding the sucrose replacement composition, then adjusting the pH value of the solution to 2-3, and heating and stirring; (3) pouring the pectin solution after heating and stirring in step (2) into a mold and storing it in a refrigerator to obtain a sugar-reduced high-methoxyl pectin gel.

7. The method according to claim 6, characterized in that The stirring temperature in steps (1) and (2) is 50 to 70° C., and the stirring time is 1 to 10 minutes.

8. The method according to claim 6, characterized in that In step (2), the pH value of the solution is adjusted using a 0.1-0.2 M HCl solution, and the pH value of the solution is adjusted to 2.2-2.

5.

9. The method according to claim 6, characterized in that The heating and stirring temperature in step (2) is 80 to 85° C., and the heating and stirring time is 5 to 15 minutes.

10. The method according to claim 6, characterized in that: The refrigerated storage temperature in step (3) is 0 to 5° C., and the refrigerated storage time is 5 to 15 hours.

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