Citrus prebiotic gel candy and preparation method thereof

Abstract

The invention discloses citrus prebiotic gel candies and a preparation method thereof, and belongs to the technical field of food, and the citrus prebiotic gel candies are prepared by taking acid-alkali treatment water obtained after an improved capsule dressing removal process of canned citrus as an initial raw material and adding a gelling agent for auxiliary forming. The acid-base treatment water is a mixed solution with the pH value of 3.86-6, wherein the mixed solution is obtained by mixing an acid solution and an alkali solution obtained in the three-time acid-base circulation treatment process of the canned oranges and tangerines according to the proportion of 1: (1-2). On the basis of an improved capsule dressing removal process, the prebiotic gel candy is prepared from the circulating water subjected to three-time acid and alkali treatment of the canned citrus, the improved circulating water subjected to three-time acid and alkali treatment contains rich pectin, flavonoid substances and Na and K ions, and a gel basis is provided for preparation of the prebiotic gel candy.

Description

Technical Field

[0001] The invention belongs to the technical field of food, and in particular relates to a citrus prebiotic gel candy and a preparation method thereof. Background Art

[0002] Citrus is the fruit with the largest cultivation area, the highest yield and the largest consumption in my country. Canned citrus plays a leading role in the citrus processing industry. China's canned citrus exports amounted to 65,800 tons, accounting for 52.07% of the total canned fruit exports. Citrus peel is rich in a variety of ingredients, including cellulose, pectin, essential oils, pigments, flavonoids, etc. At present, the main way to utilize citrus peel residue is to extract essential oils, pigments, pectin, hesperidin, etc. from it; another way of utilization is to use microbial fermentation to produce fruit vinegar, lactic acid beverages, feed or cultivate edible fungi, etc. Although citrus peel is rich in pectin, glycosides, sugars, vitamins and fibers and other effective ingredients, at present, China's citrus production industry mainly takes its flesh, and only a few citrus peels are used, while the peel residue, which accounts for 40%-50% of the whole fruit, is discharged as garbage. The peel residue is very easy to mold and stink, which is extremely harmful to humans, animals and crops, and has become one of the important sources of pollution. Therefore, the comprehensive utilization of citrus peel is an environmentally friendly measure and a need for human sustainable development.

[0003] Citrus contains a large amount of flavonoids, which have the functions of reducing myocardial oxygen consumption, increasing the flow of coronary arteries and cerebral blood vessels, resisting arrhythmia, softening blood vessels, lowering blood sugar and blood lipids, anti-oxidation, eliminating free radicals in the body, anti-aging, and enhancing the body's immunity. Citrus contains pectin, which can exert its physiological activities, such as immunomodulation and inhibiting selective fermentation by intestinal microorganisms. Acid-base treated circulating water is produced during the preparation of citrus cans, which contains a large number of beneficial ingredients such as glucose, arabinose, galacturonic acid and pectin. The prior art has disclosed a technical solution for preparing electrolyte beverages by mixing the circulating water of the first acid-base treatment with the circulating water of the second acid-base treatment, but the circulating water of the third acid-base treatment is too viscous and is not suitable for making electrolyte beverages. If it is directly discharged, it will cause eutrophication of the water body. However, the pectin polysaccharide and flavonoid content in the circulating water of the third acid-base treatment is relatively high, and the use of the circulating water of the third acid-base treatment to make sugar-free and prebiotic-rich gel candies will have a broad market in the future. However, due to the high content of neutral sugar in pectin polysaccharide in the tertiary acid-base treatment circulating water, direct use for preparing gel candy requires a large amount of sucrose and calcium ions, and the strength of the formed gel is not enough. Furthermore, there is no method disclosed in the prior art for preparing gel candy directly using the tertiary acid-base treatment circulating water of citrus can.

[0004] Therefore, how to provide a method for utilizing the circulating water from the three acid-base treatments of canned citrus fruits is a technical problem that those skilled in the art urgently need to solve. Summary of the invention

[0005] In order to solve the above technical problems, the present invention proposes a sucrose-free citrus prebiotic gel candy prepared by using circulating water obtained by three acid-base treatments of citrus cans and a preparation method thereof.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A citrus prebiotic gel candy is prepared by using acid-base treated water from an improved citrus canning decapsulation process as an initial raw material and adding a gelling agent to assist in molding;

[0008] The invention comprises the following raw materials in parts by weight:

[0009] 80 parts of acid-base treated water, 14.5 parts of gelling agent, 20 parts of sugar alcohol and 1.6 parts of auxiliary materials;

[0010] The acid-base treated water is a mixture of acid solution and alkali solution obtained during the three acid-base cycle treatment of canned citrus in a ratio of 1:(1-2) to obtain a pH value of 3.86-6;

[0011] The formula of the improved cyst coat removal process is as follows: 0.4% food-grade citric acid and 0.1% food-grade HCl solution are used as acid solution, and 0.2% food-grade NaOH and 0.1% food-grade KOH solution are used as alkali solution.

[0012] Beneficial effects: The acid solution obtained during the three-cycle acid-base cycle treatment of canned citrus contains rich citrate ions and chloride ions. Chloride ions can maintain the electrolyte balance of the human body, quickly relieve fatigue, and improve muscle exercise ability. After being absorbed, citrate can be quickly converted into glycogen and stored in the liver or muscles to reduce the formation of cholesterol. The alkaline solution contains rich pectin and flavonoids. The potential prebiotic pectin and flavonoids have the effects of lowering fat and weight, improving metabolic syndrome and reducing inflammation.

[0013] Preferably, the gelling agent comprises the following raw materials in parts by weight: 12 parts of gelatin, 1 part of konjac gum, and 1.5 parts of carrageenan.

[0014] Beneficial effects: With the increase of carrageenan addition, the comprehensive sensory score of citrus prebiotic jelly candy shows a trend of first rising and then falling, and the trend of change is more significant. When the amount of carrageenan added is 1.5g, the comprehensive sensory score of citrus jelly candy is the highest. When the amount of carrageenan added is too low, the product has poor cohesion, is inelastic and sticky when chewing, resulting in a low comprehensive sensory score of the product. When the amount of carrageenan added is too high, the product has poor elasticity due to the excessive viscosity of the carrageenan colloid.

[0015] As the amount of konjac gum added gradually increased, the elasticity of the citrus gummy candy gradually increased, the chewiness gradually strengthened, and the sensory score gradually increased; but when the amount of konjac gum added exceeded 2g, due to the excessive amount of konjac gum added, the texture of the candy became too tight and hard, the chewiness decreased, and the sensory score began to decrease.

[0016] Preferably, the carrageenan is a mixture of k-carrageenan and L-carrageenan in a ratio of 1:2.

[0017] Beneficial effects: k-carrageenan can form gel when combined with K ions, and L-carrageenan can form gel when combined with Na ions. Since the ratio of K ions and Na ions added to the alkali solution is 1:2, it is determined that k-carrageenan and L-carrageenan are mixed in a ratio of 1:2.

[0018] Preferably, the sugar alcohol is obtained by mixing isomalt and xylitol in a mass ratio of 9:1.

[0019] Beneficial effects: The combination of isomalt and xylitol not only ensures the pure sweetness, but also has low hygroscopicity and health-care effects. Both isomalt and xylitol are not easy to cause an increase in blood sugar levels and are suitable for diabetics. Both have prebiotic effects, can promote the growth and reproduction of probiotics, and are beneficial to human health. When the amount of sugar alcohol added is too low, the sweetness of the product is low, highlighting the sour taste of the soft candy, resulting in a low overall sensory score for the product. When the amount of sugar alcohol added is too high, the soft candy is prone to precipitating sugar bodies and breeding microorganisms, leading to deterioration, which is not conducive to preservation, resulting in a low overall sensory score for the product.

[0020] Preferably, the auxiliary materials include 1.2 parts of calcium lactate and 0.4 parts of citric acid.

[0021] More preferably, the auxiliary materials also include flavors, and those skilled in the art can adaptively adjust the amount of flavors added according to flavor requirements.

[0022] Beneficial effects: Different brands of citrus flavors have different aroma concentrations, so the amount added needs to be adjusted according to actual conditions.

[0023] A method for preparing citrus prebiotic gel candy comprises the following steps:

[0024] The sugar alcohol is dissolved in water and added to the acid-base treated water for boiling. After boiling, the pre-swollen gel is added to mix after the temperature drops. After cooling, auxiliary materials are added to mix evenly. Finally, the citrus prebiotic gel candy is obtained by pouring, molding and drying.

[0025] The boiling temperature of the sugar solution is 115°C to 120°C, and the boiling end point is when the sugar content reaches 65 to 70°Bx.

[0026] Preferably, the temperature is lowered to 100°C, and the cooling is cooled to 85°C.

[0027] Preferably, the drying is carried out in an environment with a temperature of 30° C. and a relative humidity of less than 45% until the moisture content is less than 35%.

[0028] Beneficial effect: The mixed liquid is still liquid at 85°C, which can dissolve the auxiliary materials and mix them evenly with other raw materials.

[0029] Compared with the prior art, the present invention has the following advantages and technical effects:

[0030] The present invention uses the tertiary acid-base treatment circulating water of citrus cans to make a prebiotic gel candy based on the improved decapping process. The improved tertiary acid-base treatment circulating water contains rich pectin, flavonoids and Na and K ions, which provides a gel basis for the production of prebiotic gel candy. The present invention converts citrus can wastewater into healthy food, which is in line with the concept of energy conservation and emission reduction and green development, and has huge economic and health value. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0032] Figure 1 Actual photo of the citrus prebiotic gel candy obtained in Example 1;

[0033] Figure 2 This is the effect of the ratio of acid-base mixture on the quality of citrus jelly;

[0034] Figure 3 This is the effect of citric acid addition on the quality of citrus jelly;

[0035] Figure 4 This is the effect of calcium lactate addition on the quality of citrus soft candy;

[0036] Figure 5 The response curves of the three colloid concentrations on the hardness of gel candy;

[0037] Figure 6 The response curves of the three colloid concentrations on the cohesiveness of gel candy;

[0038] Figure 7 The response curves of the three colloid concentrations on the elasticity of gel candy;

[0039] Figure 8 The response curves of the three colloid concentrations on the recovery of gel candy. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0042] The embodiment of the present invention discloses a citrus prebiotic gel candy, which is prepared by using acid-base treated water after the improved decapping process of citrus can as the initial raw material and adding a gelling agent to assist in molding;

[0043] The invention comprises the following raw materials in parts by weight:

[0044] 80 parts of acid-base treated water, 14.5 parts of gelling agent, 20 parts of sugar alcohol and 1.6 parts of auxiliary materials;

[0045] The acid-base treated water is a mixture of acid and alkali obtained during the three acid-base cycle treatment of canned citrus in a ratio of 1:(1-2) to obtain a pH value of 3.86-6;

[0046] The formula of the improved cyst coat removal process is as follows: 0.4% food-grade citric acid and 0.1% food-grade HCl solution are used as acid solution, and 0.2% food-grade NaOH and 0.1% food-grade KOH solution are used as alkali solution.

[0047] In a preferred embodiment, the gelling agent comprises the following raw materials in parts by weight: 12 parts of gelatin, 1 part of konjac gum, and 1.5 parts of carrageenan.

[0048] In a preferred embodiment, the carrageenan is a mixture of k-carrageenan and L-carrageenan in a ratio of 1:2.

[0049] In a preferred embodiment, the sugar alcohol is obtained by mixing isomalt and xylitol in a mass ratio of 9:1.

[0050] In a preferred embodiment, the auxiliary materials include 1.2 parts of calcium lactate and 0.4 parts of citric acid.

[0051] In a more preferred embodiment, the auxiliary materials further include flavors, and those skilled in the art can adaptively adjust the amount of flavors added according to flavor requirements.

[0052] The embodiment of the present invention also discloses that the sugar alcohol is dissolved in water and then added to the acid-base treated water for boiling, after boiling is completed and the temperature is lowered, the pre-swollen gel is added for blending, auxiliary materials are added for even mixing after cooling, and finally the citrus prebiotic gel candy is obtained through pouring, molding and drying.

[0053] The boiling temperature of the sugar solution is 115°C to 120°C, and the boiling end point is when the sugar content reaches 65 to 70°Bx.

[0054] Preferably, the temperature is lowered to 100°C, and the cooling is cooled to 85°C.

[0055] Preferably, the drying is carried out in an environment with a temperature of 30° C. and a relative humidity of less than 45% until the moisture content is less than 35%.

[0056] Unless otherwise specified, the raw materials in the embodiments of the present invention are purchased from commercial sources. The formula of the improved de-shelling process for canned citrus is: 0.4% food-grade citric acid and 0.1% food-grade HCl solution as the acid solution, and 0.2% food-grade NaOH and 0.1% food-grade KOH solution as the alkali solution.

[0057] The acid-base treated water is a mixture of acid solution and alkali solution obtained in the three-time acid-base cycle treatment process of the improved de-shelling process of citrus canning, with a pH value of 3.86-6 obtained by mixing the acid solution and the alkali solution in a ratio of 1:(1-2);

[0058] Unless otherwise specified, the room temperature described in the embodiments of the present invention refers to 25±3°C.

[0059] Example 1

[0060] A citrus prebiotic gel candy comprises the following raw materials in parts by weight:

[0061] 80 parts of acid-base treated water (acid and alkali solution are mixed in a mass ratio of 1:2, and pH=6), 12 parts of gelatin, 1 part of konjac gum, 1.5 parts of carrageenan (k-carrageenan and L-carrageenan are mixed in a mass ratio of 1:2), 20 parts of sugar alcohol (isomalt and xylitol are mixed in a mass ratio of 9:1), 1.2 parts of calcium lactate, and 0.4 parts of citric acid;

[0062] A method for preparing citrus prebiotic gel candy comprises the following steps:

[0063] (1) The above gelling agent and water are prepared in a ratio of 1:2, and the mixture is dissolved at a temperature of 75-80° C. to prepare a preformed liquid without micelles, which is the gelling agent solution for later use;

[0064] (2) dissolving the calcium lactate, citric acid and sodium bicarbonate in water to obtain an auxiliary material solution for later use;

[0065] After the sugar alcohol is dissolved in water, it is added to the acid-base treated water, boiled at 115-120°C until the sugar content is 65-70°Bx, then the above-mentioned gelling agent solution is added and mixed evenly, and then the mixture is allowed to stand and cool to 85°C, and then the auxiliary material solution is added and mixed evenly, and finally the mold is arranged, the mixed syrup is allowed to stand and deaerate, and then poured while hot, and the syrup is demolded and taken out after solidification, and then the formed sugar blocks are placed in an environment with a temperature of 25°C and a relative humidity of less than 45% to dry for about 24 hours, and the moisture content of the product is tested. When it is less than 35%, the drying is terminated and the product is bagged to obtain the citrus prebiotic gel candy.

[0066] Citrus prebiotic gel candy real picture Figure 1 As shown, it can be seen that the product is orange-yellow in color, complete in shape, non-sticky, has good toughness and chewiness, has no starch-coating phenomenon, has a citrus aroma and flavor, and has evenly distributed particles.

[0067] Comparative Example 1

[0068] A citrus prebiotic gel candy, which is different from Example 1 in that the amount of acid-base treated water added is 70 parts, and specifically includes the following raw materials in parts by weight:

[0069] 70 parts of acid-base treated water (acid and alkali solution are mixed in a mass ratio of 1:2, and pH=6), 12 parts of gelatin, 1 part of konjac gum, 1.5 parts of carrageenan (k-carrageenan and L-carrageenan are mixed in a mass ratio of 1:2), 20 parts of sugar alcohol (isomalt and xylitol are mixed in a mass ratio of 9:1), 1.2 parts of calcium lactate, and 0.4 parts of citric acid;

[0070] The remaining process steps and parameters are the same as those in Example 1.

[0071] Comparative Example 2

[0072] A citrus prebiotic gel candy, which is different from Example 1 in that the amount of acid-base treated water added is 90 parts, and specifically includes the following raw materials in parts by weight:

[0073] 90 parts of acid-base treated water (acid and alkali solution are mixed in a mass ratio of 1:2, and pH=6), 12 parts of gelatin, 1 part of konjac gum, 1.5 parts of carrageenan (k-carrageenan and L-carrageenan are mixed in a mass ratio of 1:2), 20 parts of sugar alcohol (isomalt and xylitol are mixed in a mass ratio of 9:1), 1.2 parts of calcium lactate, and 0.4 parts of citric acid;

[0074] The remaining process steps and parameters are the same as those in Example 1.

[0075] Technical effects:

[0076] 1. Sensory Evaluation

[0077] Taking sensory scores as evaluation indicators, 10 students were selected as sensory assessors. The sensory evaluation is shown in Table 1 below:

[0078] Table 1 Gel candy sensory evaluation standard

[0079]

[0080] 2. Texture Determination

[0081] Texture is a physical property that describes the structure of food and is a linguistic expression of the taste of food. Texture is related to the morphology, chemical composition, external forces and other properties of food. The full texture test TPA (Texture Profile Analysis) is also called the double chewing test. It mainly uses the probe of the texture analyzer to simulate the chewing movement of the human mouth, compresses the solid or semi-solid sample twice, connects the test to the computer, and outputs the texture test curve through the display. The software can analyze the following full texture characteristic parameters: brittleness, hardness, elasticity, viscosity, cohesion, adhesiveness, chewiness, and resilience.

[0082] 1. Parameter setting

[0083] Using cylindrical probe P / 50, pre-speed 1mm / s, TPA test mode, using P / 50 cylindrical probe, pre-test speed 1mm / s, test and post-test speed 5mm / s, compression rate: 50%, trigger force: 5g, dwell time: 5s. Take the middle flat and uniform part (1.4cm×1.4cm) of each soft candy for measurement, and each group of samples is measured 3 times in parallel.

[0084] 2. Description of measurement indicators

[0085] Hardness: It is the maximum peak force value of the first compression, which can also be expressed as firmness;

[0086] Brittleness: Fracture does not necessarily occur during the compression process. If fracture occurs during the first compression process, an obvious peak will appear in the curve, and this peak is defined as brittleness. If there is only one peak, it is defined as hardness, and there is no brittleness value.

[0087] Adhesion: The negative peak area of ​​the curve from the time when the first compression curve reaches the zero force point to the beginning of the second compression curve. This value represents the total work required to overcome the attraction between the surfaces of the probe and the sample when they come into contact. When adhesion > cohesion, it means that some sample residue will be attached to the probe;

[0088] Elasticity: The height ratio of a deformed sample after compression to the condition before deformation after the deformation force is removed. Elasticity is expressed by the ratio of the sample recovery height detected in the second compression to the first compression deformation;

[0089] Cohesion: The relative resistance of the test sample to the second compression after the first compression deformation, which is expressed on the curve as the ratio of the positive work done by the two compressions (Area 2 / Area 1). This parameter is used to characterize the cohesion strength of the internal structure of the sample;

[0090] Cohesiveness: This value indicates the energy required to chew semi-solid food until it can be swallowed. The value is expressed as the product of hardness and cohesion (hardness × cohesion).

[0091] Chewability: Only used to describe solid test samples, indicating the energy required to chew the solid sample into a stable state when swallowed. The value is expressed as the product of gummies and elasticities (hardness × cohesion × elasticity). Most samples will choose one of the gummies or chewiness indicators based on the edible form;

[0092] Resilience: It is the ratio of the compression energy to the recovery energy of the sample during the first compression cycle (Area5 / Area4). This value indicates the degree to which the sample recovers to its original state after being deformed at the same speed and pressure.

[0093] 3. Principle of the method

[0094] The present invention uses an instrument that simulates human touch and analyzes and detects the physical properties of food under force. There is a force sensing element at the connection between the mechanical arm of the host and the test probe, which can sense the reaction force of the food material on the probe, and transmit this mechanical signal to the computer, and convert it into digital records and graphical representations, so as to quickly and intuitively describe the force conditions of the sample. Before the sample test, the appropriate mechanical arm movement speed is designed through computer program control. When the sensor contacts the object to be tested and reaches the set trigger force or the set trigger depth, the computer records at the set speed and plots it in a rectangular coordinate system. The time displacement can be freely converted, and the stress and strain relationship of the object to be tested can be calculated.

[0095] 3. According to the above-mentioned testing standards, the sensory score of the gel candy obtained in Example 1 was 91 points, and the sensory scores of Comparative Examples 1-2 were 85 points and 78 points respectively. This is because the acid-base treated water is rich in pectin polysaccharides. When the addition amount is reduced to 70 parts, the amount of calcium ions is relatively excessive, and the mouthfeel of the formed gel is hard and the elasticity is slightly reduced; when the addition amount is increased to 90 parts, the amount of pectin polysaccharides is also increased, and the gel strength is reduced, the toughness is insufficient, and there is a slight stickiness to the teeth.

[0096] 4. Single Factor Experiment

[0097] 1. Determine the ratio of acid-base mixture

[0098] Fixed carrageenan 1g, konjac gum 1g, sorbitol 15g, citric acid 0.05g, acid-base treated water mass 80g, sweet orange essence appropriate amount. Study the changes in gel texture and sensory properties under the conditions of acid-base treated water mass ratio of acid to alkali solution of 1:0.5, 1:1, 1:1.5, 1:2. And measure the pH value of the mixed solution with different ratios.

[0099] Effect of the ratio of acid and alkali in acid-base treatment water on the quality of citrus jelly candy Figure 2 As shown in the figure, the ratio of acid and alkali affects the flavor, color and taste of the finished soft candy. When the ratio of acid and alkali is 1:0.5, 1:1 and 1:1.5, the pH values ​​are 3.34, 3.86, 4.12 and 4.68 respectively. When the amount added is too much, the characteristic aroma of citrus extract is strong, the color is darker, and the pH value is too high, which is difficult for some consumers to accept. When the ratio of alkali is low, the pH value is acidic, the color and aroma are lighter, and the taste is not good. Figure 2 It can be seen that before the ratio of citrus acid-base mixture reaches 1:1.5, the sensory score increases with the increase of the ratio; when the optimal condition of the acid-base mixture ratio is 1:2, the pH value is 6.

[0100] 2. Determination of the amount of citric acid added

[0101] Fixed carrageenan 1g, konjac gum 1g, sorbitol 15g, acid-base treated water 80g, wherein the mass ratio of acid to alkali is 1:1.5, and sweet orange essence is appropriate. The changes in gel texture and sensory properties when sorbitol addition amounts are 10g, 15g, 20g, and 25g are studied.

[0102] The effect of citric acid addition on the quality of citrus jelly candy is shown in the following table. Figure 3 As shown in the figure, the amount of citric acid added has an effect on the flavor, hardness, and gel strength of citrus jelly candy. Figure 3 It can be seen that the amount of citric acid added has a significant effect on the sensory score. Citric acid can adjust the taste, making the candy sweet and sour and richer in flavor. Moreover, the addition of citric acid will cause the pH of the soft candy to drop and cause the gelling agent to decompose, thereby reducing the hardness of the soft candy. Before the amount of citric acid added reaches 0.4g, the sensory score of the candy gradually increases with the increase in the amount of added; after the amount of citric acid added exceeds 0.4g, the sour taste of the soft candy increases, the hardness and elasticity are poor, and the sensory score shows a downward trend. Therefore, the optimal amount of citric acid added is 0.4g.

[0103] 3. Determination of the amount of calcium lactate added

[0104] Fixed carrageenan 1g, konjac gum 1g, sorbitol 15g, citric acid 0.05g, acid-base treated water 80g, wherein the mass ratio of acid to alkali is 1:1.5, and sweet orange flavor is appropriate. The changes in gel texture and sensory properties when calcium lactate alcohol is added in amounts of 0g, 0.4g, 0.8g, and 1.2g are studied.

[0105] The effect of calcium lactate addition on the quality of citrus soft candy Figure 4 As shown, calcium lactate reacts with citrus extract pectin to form a bridge-structured gel structure. Adding a certain amount of calcium lactate can improve the gel strength of soft candy, improve the quality, stabilize the product gel system, and improve the gel strength of soft candy. Figure 4 As shown, it can be seen that with the increase of the amount of calcium lactate added, the harder the jelly candy is, the higher the sensory score is. Therefore, the optimal amount of calcium lactate added is 1.2g.

[0106] 5. Response surface analysis experiment

[0107] 1. Research on the formula of gel candy

[0108] K-carrageenan and L-carrageenan are mixed in a ratio of 1:2 to obtain carrageenan, and at the same time, the raw materials calcium lactate 1.2g, citric acid 0.05g, sugar alcohol (sorbitol and xylitol mass ratio is 1:1) 20g, acid-base treated water 80mL, wherein the mass ratio of acid solution to alkali solution is 1:2, pH=6, and the total amount of water added is about 50mL.

[0109] Taking into account the experimental results of the influence of single factors on the sensory comprehensive score and hardness of citrus jelly candy, according to the Box-Behnken experimental design principle, carrageenan (A), konjac gum (B) and gelatin (C) were designed as response factors. The Box-Behnken response surface optimization method was used to design a response surface experiment. The hardness, elasticity, cohesion and recovery values ​​of the texture were used as evaluation indicators. See Table 2 for details.

[0110] Table 2 Response surface experimental design

[0111] level Carrageenan / g Konjac gum / g Gelatin / g 1 0.6 0.6 6 2 0.9 0.9 9 3 1.2 1.2 12

[0112] According to the above response surface experimental design, 17 groups of experiments were carried out, and the results are shown in Table 3.

[0113] Table 3 Response surface analysis experimental design and results

[0114] Serial number A Carrageenan / g B Konjac gum / g C gelatin / g hardness elasticity Cohesion Responsiveness 1 1.20 1.20 9.00 936.85 3.9023 0.9585 0.8872 2 1.60 0.80 9.00 1356.91 3.9043 0.9625 0.8439 3 1.60 1.20 6.00 956.333 3.3189 0.9486 0.8784 4 1.60 1.60 9.00 921.26 3.9681 0.9635 0.8689 5 1.20 1.20 9.00 1160.14 3.5288 0.9255 0.7164 6 1.20 0.80 6.00 1621.85 3.5156 0.9512 0.8354 7 1.20 1.20 9.00 1536.38 3.4342 0.9557 0.8185 8 1.20 1.20 9.00 1197.48 3.463 0.8759 0.6658 9 0.80 1.20 12.00 1962.3 3.5967 0.9322 0.7937 10 0.80 0.80 9.00 1586.96 3.3848 0.9583 0.8288 11 0.80 1.60 9.00 999.59 3.8806 0.9362 0.8088 12 1.20 1.20 9.00 1833.77 3.4812 0.937 0.8010 13 1.20 1.60 12.00 1668.8 3.4702 0.9608 0.8528 14 1.20 1.60 6.00 1221.57 2.0956 0.9418 0.8004 15 0.80 1.20 6.00 1535.61 3.4516 0.9475 0.8733 16 1.60 1.20 12.00 728.67 3.6544 0.942 0.7378 17 1.20 0.80 12.00 1101.46 3.6255 0.9418 0.7999

[0115] The software Design-Expert13.0.1.1 was used, with gelatin concentration, carrageenan concentration, and konjac gum concentration as response variables, and the gel candy hardness index value (response value) was compared with the data in the above table for analysis and processing, and the variance analysis table of the regression equation in Table 4 was obtained.

[0116] Table 4. Variance analysis table of regression model

[0117]

[0118]

[0119] Note: ** indicates extremely significant level (p<0.01); * indicates significant level (p<0.05)

[0120] 2. Response Surface Analysis

[0121] By using the regression model variance analysis, the software was used to produce contour lines and three-dimensional graphs of the effects of gelatin concentration, carrageenan concentration, and konjac gum concentration on the hardness, cohesion, elasticity, and resilience of the jelly candy. The strength of the interaction between the factors was determined by the shape of the contour lines (circular and elliptical). If the contour lines were circular, the interaction was not significant. On the contrary, if the contour lines were elliptical, the interaction was significant.

[0122] (1) Effects of three colloid concentrations on the hardness of gel candy

[0123] Table 5 Effect of three colloid concentrations on the hardness of gel candy

[0124] Sources of variance sum of squares Degrees of Freedom Mean Square F-number P-value Significance Model <![CDATA[1.726×10 6 ]]> 9 <![CDATA[1.918×10 5 ]]> 4.23 0.0351 * A-Carrageenan 9436.84 1 9436.84 0.2083 0.6619 B-Konjac Gum 88678.76 1 88678.76 1.96 0.2045 C-Gelatin <![CDATA[1.281×10 5 ]]> 1 <![CDATA[1.281×10 5 ]]> 2.83 0.1365 AB 24891.37 1 24891.37 0.5495 0.4826 AC <![CDATA[3.271×10 5 ]]> 1 <![CDATA[3.271×10 5 ]]> 7.22 0.0312 BC 40328.01 1 40328.01 0.8904 0.3768 <![CDATA[A 2 ]]> <![CDATA[3.750×10 5 ]]> 1 <![CDATA[3.750×10 5 ]]> 8.28 0.0237 * <![CDATA[B 2 ]]> <![CDATA[2.832×10 5 ]]> 1 <![CDATA[2.832×10 5 ]]> 6.25 0.0410 * <![CDATA[C 2 ]]> <![CDATA[3.329×10 5 ]]> 1 <![CDATA[3.329×10 5 ]]> 7.35 0.0302 * Residual <![CDATA[3.171×10 5 ]]> 7 45294.29 Lack of Fit <![CDATA[1.848×10 5 ]]> 3 61594.04 1.86 0.2767 Not significant error <![CDATA[1.323×10 5 ]]> 4 33069.49 sum <![CDATA[2.043×10 5 ]]> 16

[0125] Note: *p<0.05 significant, **p<0.01 extremely significant

[0126] The response curves of the three colloid concentrations on the hardness of gel candy are as follows: Figure 5 As shown, it can be seen that with the increase of gelatin concentration, the hardness of the jelly candy gradually increases, and with the increase of carrageenan and konjac gum concentrations, the hardness of the jelly candy gradually increases. It can be seen from Table 5 that the interaction between gelatin concentration and gellan gum concentration on the hardness of the jelly candy is significant.

[0127] (2) Effects of three colloid concentrations on the cohesiveness of gel candies

[0128] Table 6 Effects of three colloid concentrations on the cohesiveness of gel candies

[0129] Sources of variance sum of squares Degrees of Freedom Mean Square F-number P-value Significance Model 0.0058 9 0.0006 4.32 0.0333 Significant* A-Carrageenan 0.0001 1 0.0001 0.7347 0.4197 B-Konjac Gum 0.0014 1 0.0014 9.29 0.0187 * C-Gelatin 0.0026 1 0.0026 17.31 0.0042 ** AB <![CDATA[2.500×10 -7 ]]> 1 <![CDATA[2.500×10 -7 ]]> 0.0017 0.9686 AC <![CDATA[4.675×10 -6 ]]> 1 <![CDATA[4.675×10 -6 ]]> 0.0312 0.8648 BC 0.0008 1 0.0008 5.52 0.0512 <![CDATA[A 2 ]]> 0.0004 1 0.0004 2.75 0.1410 <![CDATA[B 2 ]]> 0.0000 1 0.0000 0.2136 0.6580 <![CDATA[C 2 ]]> 0.0005 1 0.0005 3.35 0.1097 Residual 0.0010 7 0.0001 Lack of Fit 0.0006 3 0.0002 1.80 0.2873 Not significant error 0.0004 4 0.0001 sum 0.0069 16

[0130] Note: *p<0.05 significant, **p<0.01 extremely significant

[0131] The response curves of the three colloid concentrations on the cohesiveness of gel candy are as follows: Figure 6 As shown, it can be seen that with the increase of gelatin and konjac gum concentrations, the cohesion of the jelly candy first slowly increases and then decreases, indicating that the interaction of the three colloid concentrations on the hardness of the jelly candy is not significant.

[0132] (3) Effects of three colloid concentrations on the elasticity of gel candies

[0133] Table 7 Effects of three colloid concentrations on the elasticity of gel candy

[0134]

[0135]

[0136] Note: *p<0.05 significant, **p<0.01 extremely significant

[0137] The response curves of the three colloid concentrations on the elasticity of gel candy are as follows: Figure 7 As shown, it can be seen that with the increase of konjac gum concentration, the elasticity of the jelly candy gradually increases. From Table 7, it can be seen that the interaction effect of konjac gum concentration on the elasticity of the jelly candy is significant.

[0138] (4) Effects of three colloid concentrations on the recovery of gel candies

[0139] Table 8 Effect of three colloid concentrations on the recovery of gel candy

[0140] Sources of variance sum of squares Degrees of Freedom Mean Square F-number P-value Significance Model 0.0518 9 0.0058 7.20 0.0082 Significant* A-Carrageenan 0.0001 1 0.0001 0.0650 0.8061 B-Konjac Gum 0.0131 1 0.0131 16.43 0.0048 * C-Gelatin 0.0323 1 0.0323 40.38 0.0004 ** AB 0.0002 1 0.0002 0.2034 0.6657 AC 0.0006 1 0.0006 0.6883 0.4341 BC 0.0014 1 0.0014 1.73 0.2303 <![CDATA[A 2 ]]> 0.0000 1 0.0000 0.0128 0.9130 <![CDATA[B 2 ]]> <![CDATA[3.085×10 -7 ]]> 1 <![CDATA[3.085×10 -7 ]]> 0.0004 0.9849 <![CDATA[C 2 ]]> 0.0042 1 0.0042 5.27 0.0553 Residual 0.0056 7 0.0008 Lack of Fit 0.0016 3 0.0005 0.5322 0.6843 Not significant error 0.0040 4 0.0010 sum 0.0574 16

[0141] Note: *p<0.05 significant, **p<0.01 extremely significant

[0142] The response curves of the three colloid concentrations on the recovery of gel candy are as follows: Figure 8 As shown, it can be seen that with the increase of konjac gum concentration, the resilience of the jelly candy first slowly increases and then decreases. With the increase of gelatin concentration, the resilience of the jelly candy gradually increases. It can be seen from Table 8 that the interaction between gelatin concentration and konjac gum concentration on the jelly candy is not significant.

[0143] In summary, the response surface optimization was performed using Design Expert 13.1.0.1 software, and the optimal conditions obtained were: gelatin addition of 12 g, carrageenan addition of 1.5 g, and konjac gum addition of 1 g.

[0144] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A citrus prebiotic gel candy, characterized in that: The product is prepared by using the acid-base treated water after the improved decapping process of citrus can as the initial raw material and adding a gelling agent to assist in molding; The invention comprises the following raw materials in parts by weight: 80 parts of acid-base treated water, 14.5 parts of gelling agent, 20 parts of sugar alcohol and 1.6 parts of auxiliary materials; The acid-base treated water is a mixed solution having a pH value of 3.86-6 obtained by mixing acid solution and alkali solution obtained during the three acid-base cycle treatment of canned citrus in a ratio of 1:(1-2).

2. The citrus prebiotic gel candy according to claim 1, characterized in that: The gelling agent comprises the following raw materials in parts by weight: 12 parts of gelatin, 1 part of konjac gum and 1.5 parts of carrageenan.

3. The citrus prebiotic gel candy according to claim 2, characterized in that: The carrageenan is a mixture of k-carrageenan and L-carrageenan in a ratio of 1:

2.

4. The citrus prebiotic gel candy according to claim 1, characterized in that: The sugar alcohol is obtained by mixing isomalt and xylitol in a mass ratio of 9:

1.

5. The citrus prebiotic gel candy according to claim 1, characterized in that: The auxiliary materials include 1.2 parts of calcium lactate and 0.4 parts of citric acid.

6. A method for preparing a citrus prebiotic gel candy according to any one of claims 1 to 5, characterized in that: The following steps are involved: The sugar alcohol is dissolved in water and added to the acid-base treated water for boiling. After boiling, the pre-swollen gel is added to mix after the temperature drops. After cooling, auxiliary materials are added to mix evenly. Finally, the citrus prebiotic gel candy is obtained by pouring, molding and drying.

7. The citrus prebiotic gel candy according to claim 6, characterized in that: The boiling temperature of the sugar solution is 115°C to 120°C, and the boiling end point is when the sugar content reaches 65 to 70°Bx.

8. The citrus prebiotic gel candy according to claim 6, characterized in that: The temperature reduction is to reduce the temperature to 100°C, and the cooling is to cool to 85°C.

9. The citrus prebiotic gel candy according to claim 6, characterized in that: The drying is performed in an environment with a temperature of 30° C. and a relative humidity of less than 45% until the moisture content is less than 35%.

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