Compound glue and preparation method thereof

Abstract

The invention relates to a compound gum and a preparation method thereof, and the preparation method comprises the following steps: (1) uniformly mixing kappa-carrageenan powder and cassia gum powder according to a mass ratio of 2: 3-4: 1 to obtain kappa-carrageenan and cassia gum mixed powder; (2) dispersing the mixed powder in salt-containing deionized water to obtain a dispersion liquid, and adjusting the pH value of a system in the dispersion liquid; and (3) stirring the dispersion liquid in a constant-temperature water bath to prepare the compound glue product. The kappa-carrageenan and cassia gum compound gum prepared by the invention has higher gel strength, better freeze-thaw stability and better thermal stability, and can meet the increasing requirements of application on gel characteristics.

Description

Technical Field

[0001] The invention relates to the technical field of food processing, in particular to a compound glue and a preparation method thereof, and also to a method for improving the gel strength of kappa-carrageenan. Background Art

[0002] Carrageenan is a linear natural high molecular weight polysaccharide containing sulfate groups. It is an alternating copolymer formed by β-(1-3)-D-galactose-4-sulfate and α-(1-4)-3,6-endo-D-galactose. Carrageenan has excellent physical functional properties, such as thickening, gelling and stability, and is widely used in the food industry, daily chemical products and biomedicine. Cassia gum is a galactomannan extracted and separated from the seeds of the leguminous plant Cassia, which is composed of a β-(1-4)-D-mannan main chain and an α-(1-6)-D-galactose side chain. Cassia gum is a non-toxic non-gelling polysaccharide and is often used as a natural food additive with both medicinal and edible properties in food applications.

[0003] Currently, the texture properties of a single gel can no longer meet the increasing application requirements in many cases. Summary of the invention

[0004] The purpose of the present invention is to overcome the problem that the existing gel texture properties cannot meet the increasing applications in many cases, especially the problem of insufficient gel strength, and to provide a method for improving the gel strength of kappa-carrageenan.

[0005] The present invention utilizes the interaction between the polysaccharides of kappa-carrageenan powder and cassia gelatin powder to improve the physical properties of the system, and utilizes the synergistic effect between two or more polysaccharides to improve certain properties, thereby achieving the purpose of taking advantage of each other's strengths and making up for each other's weaknesses.

[0006] To this end, in the first aspect of the present invention, κ-carrageenan powder and cassia gelatin powder are uniformly mixed in a mass ratio of 2:3-4:1; in the second aspect, the κ-carrageenan powder and cassia gelatin mixed powder are dispersed in deionized water with a salt concentration of 0.1-1.0wt% to form a dispersion; and according to specific process conditions, the compound rubber product prepared by the present invention can have higher gel strength, water retention and thermal stability.

[0007] The specific plan is as follows:

[0008] A method for preparing a compound rubber comprises the following steps:

[0009] (1) mixing κ-carrageenan powder and cassia gelatin powder in a mass ratio of 2:3-4:1 to obtain a mixed powder of κ-carrageenan and cassia gelatin;

[0010] (2) dispersing the mixed powder in deionized water containing salt to obtain a dispersion, and adjusting the pH value of the system in the dispersion;

[0011] (3) placing the dispersion in a constant temperature water bath for stirring to obtain a compound rubber product.

[0012] Furthermore, in step (1), the κ-carrageenan powder and the cassia gelatin powder are evenly mixed in a mass ratio of 3:2.

[0013] Optionally, in step (2), the salt comprises at least one of potassium chloride, sodium chloride or calcium chloride.

[0014] Optionally, in step (2), the concentration of the salt is 0.1-1.0 wt %.

[0015] Preferably, in step (2), the potassium chloride has a concentration of 0.6 wt%.

[0016] Preferably, in step (2), the sodium chloride has a concentration of 0.6 wt %; or the calcium chloride has a concentration of 0.4 wt %.

[0017] Optionally, in step (2), the pH value is 4 to 11;

[0018] Preferably, in step (2), the pH value is 6-7.

[0019] Optionally, in step (2), the concentration of the mixed powder in the dispersion is 0.5-2.0 wt %;

[0020] Preferably, in step (2), the concentration of the mixed powder in the dispersion is 1.5 wt %.

[0021] Furthermore, in step (3), the temperature of the constant temperature water bath is 75-95° C., and the stirring time is 20-50 min.

[0022] The present invention also protects a compound adhesive, which is prepared by the above method;

[0023] Furthermore, the gel strength of the compound glue is 1000-1960 g / cm 2 ; The thermal stability of the compound rubber is improved compared with κ-carrageenan; the water retention index is that the dehydration rate of the compound rubber is 17.48%-31.04%.

[0024] Beneficial effects:

[0025] In the present invention, kappa-carrageenan, cassia gelatin and salt are compounded in a certain ratio to achieve a synergistic effect. At the same time, in the process of preparing the compounded gel, the present invention also needs to work together with specific preparation conditions, and the gel formed after compounding has higher gel strength, better freeze-thaw stability, and better thermal stability.

[0026] Furthermore, κ-carrageenan and cassia gelatin are natural polysaccharides extracted from plants and plant seeds. They are safe, healthy, green and environmentally friendly. Cassia gelatin has a lower cost, which improves the product's cost-effectiveness.

[0027] Furthermore, the method of the present invention has simple steps and is easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solution of the present invention, the accompanying drawings will be briefly introduced below. Obviously, the accompanying drawings in the following description only relate to some embodiments of the present invention, but are not intended to limit the present invention.

[0029] Figure 1 This is the infrared spectrum of the compounded gel of κ-carrageenan and cassia gum in Example 1.

[0030] Figure 2 This is a graph showing the gel strength of the composite gels of κ-carrageenan and Cassia gum at different mass ratios in Example 1.

[0031] Figure 3 The freeze-thaw stability diagram of the compounded gel of κ-carrageenan and Cassia gelatin in different mass ratios in Example 1.

[0032] FIG4 is a graph showing the thermal stability of the composite rubber of κ-carrageenan and cassia gum at different mass ratios in Example 1; FIG4(a) is a graph showing the TG and DTG result curves of κ-carrageenan powder, cassia gum powder and the composite rubber; FIG4(b) is a graph showing the DSC result curves of κ-carrageenan powder, cassia gum powder and the composite rubber; FIG4(c) is a graph showing the DSC result curves of κ-carrageenan powder, cassia gum powder and the composite rubber;

[0033] Figure 5 The scanning electron microscope images of the composite gums of κ-carrageenan and Cassia gum in different mass ratios in Example 1;

[0034] Figure 6 This is a graph of gel strength of compound gels of κ-carrageenan and Cassia gelatin with different potassium chloride contents in Example 2;

[0035] Figure 7 This is a graph of gel strength of compound gels of κ-carrageenan and Cassia gelatin with different sodium chloride contents in Example 3;

[0036] Figure 8This is a graph of gel strength of compound gels of κ-carrageenan and Cassia gelatin with different calcium chloride contents in Example 4;

[0037] Fig. 9 This is a graph showing the gel strength of the composite gel of κ-carrageenan and Cassia gelatin at different pH values ​​in Example 5. DETAILED DESCRIPTION

[0038] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. In the embodiments, if specific techniques or conditions are not indicated, the techniques or conditions described in the literature in this area or the product specifications are carried out. The reagents used or the instruments that do not indicate the manufacturer are all conventional products that can be obtained commercially. In the following embodiments, if not specifically stated, "%" refers to weight percentage, and parts refer to weight parts.

[0039] The test methods used below include:

[0040] Gel strength: Pour the gel solution into a glass petri dish after it is completely dissolved. After gelling overnight at 20°C, use a gel tester to measure the gel strength within 20 seconds. The gel tester measures the force required to break the gel surface. The specific method is: place the sample at one end of the tray balance, and move the stainless steel cylindrical probe (1cm) of the gel tester to the sample when it touches the sample. 2 ) fixed; a beaker is placed at the other end of the pan balance, and water is evenly poured into the beaker until the gel breaks. The weight of the beaker is the gel strength value.

[0041] Water retention: Heat the sample until it dissolves, place it at room temperature for 12 hours to form a stable gel, and record the weight m1 at this time. Then freeze it at -18℃ for 24 hours, thaw the frozen sample at room temperature for 6 hours, centrifuge it at 3500rpm for 15 minutes after thawing, pour out the supernatant and weigh it, record it as m2. Use equation (1) to calculate the dehydration rate:

[0042]

[0043] Thermal stability:

[0044] Powder sample: TG-DSC analysis method is to heat the powder sample in an alumina crucible in a synchronous thermal analyzer (SDT: Q600, TA, New Castle, USA) under nitrogen environment. The test temperature is increased from 30°C to 600°C at a rate of 10°C / min.

[0045] Gel sample: DSC analysis method is to heat the gel sample in an alumina crucible in a nitrogen environment using a synchronous thermal analyzer (TA: Q50, TA, SELB, Germany). The test temperature of the gel sample is increased from 20°C to 95°C at a rate of 10°C / min.

[0046] Example 1

[0047] (1) uniformly mixing κ-carrageenan and cassia gelatin powder in mass ratios of 8:2, 6:4, 4:6, and 2:8, respectively, to form four mixtures of κ-carrageenan and cassia gelatin powder in different mass ratios;

[0048] (2) dispersing a mixture of κ-carrageenan and cassia gelatin powder at a concentration of 1.5 wt % in deionized water containing 0.12 wt % potassium chloride to prepare a dispersion;

[0049] (3) The dispersion was placed in a constant temperature water bath at 85°C and stirred for 30 min to obtain 4 composite gums of κ-carrageenan and cassia gum in different mass ratios.

[0050] The infrared spectrum of the molecular polysaccharide in the compound glue is as follows: Figure 1 As shown; the gel strength of the compound glue is as follows Figure 2 As shown; the freeze-thaw stability of the compound glue, as Figure 3 The thermal stability of the compound adhesive is shown in Figure 4 (a, b and c); the scanning electron microscope image of the compound adhesive is shown in Figure 5 shown.

[0051] The results show that:

[0052] Depend on Figure 1 It can be seen that in the spectrum of κ-carrageenan, at 3455.4 cm -1 The absorption peak at 2926cm is a broad and intense hydroxyl stretching vibration band; -1 A strong peak at 1644 cm represents the stretching vibration of the CH group; -1 The peak at 1247 cm -1 The absorption peak at 927 cm is due to the stretching of the S=O bond of the sulfate ester; -1 The peaks around 846 cm are considered to be 3,6-anhydrogalactose; -1 Some smaller peaks are attributed to galactose-4-sulfate. The spectrum of Cassia gelatin also shows 3000-3700 cm -1 The OH stretching vibration band at 2800-3000cm -1 CH stretching vibration band at 1153-1026cm -1The broad band between 812cm is due to the stretching vibration of CO in the COH bond, which is related to the sugar composition of galactomannan. -1 and 873cm -1 The peaks at are attributed to the α-D-galactopyranose unit and the β-D-mannopyranose unit, respectively. The OH stretching vibration peak of the κ-carrageenan-cassia gum blends of all proportions is between κ-carrageenan and cassia gum. The blending of the two polysaccharides leads to the formation of hydrogen bonds, which increases the electron-donating groups near the hydroxyl group. Therefore, the hydroxyl absorption vibration peak of the blended gum moves to the low band, proving that the intermolecular hydrogen bonding force is enhanced after blending, confirming the occurrence of interaction between the two polysaccharides in the blending system.

[0053] Depend on Figure 2 It can be seen that after κ-carrageenan and cassia gelatin are mixed, the gel strength shows a trend of first increasing and then decreasing, and reaches the maximum when the mass ratio of κ-carrageenan to cassia gelatin is 6:4, and the gel strength is significantly improved.

[0054] Depend on Figure 3 It can be seen that freeze-thaw stability can reflect the water retention performance of the gel. κ-carrageenan has the defect of easy dehydration and poor freeze-thaw stability. After one freeze-thaw, the dehydration is as high as 43%. The freeze-thaw stability of the compounded gel formed after compounding with Cassia gum has decreased, and the lowest can reach 17.48%. This shows that the compounded gel of κ-carrageenan and Cassia gum not only has a significant improvement in strength, but also has a significant improvement in water retention, especially when the mass ratio of κ-carrageenan to Cassia gum is 6:4, it reaches the best.

[0055] As shown in Figure 4(a), in the temperature range of 30℃-250℃, the weight of κ-carrageenan decreased by 15%, the weight of cassia gum decreased by 11%, and the weight of κ-carrageenan-cassia gum (compound of κ-carrageenan and cassia gum) decreased by 11.2%; among them, the mass ratio of κ-carrageenan powder to cassia gum powder in the compound was 6:4. This part of the weight loss is the loss of free water, indicating that the hygroscopicity of κ-carrageenan is reduced. In the DSC curve of Figure 4(b), the small exothermic peak of κ-carrageenan at 255℃ indicates the decomposition of κ-carrageenan, and there is no exothermic peak in κ-carrageenan-cassia gum, which is attributed to the interaction between κ-carrageenan and cassia gum. Figure 4(c) is the DSC curve of the gel sample at 30℃-90℃. The change of the thermal decomposition temperature of the sample can indirectly reflect the change of thermal stability. The phase transition temperatures of κ-carrageenan and κ-carrageenan-cassia gum are 57℃ and 60℃, respectively. The melting temperature of κ-carrageenan-cassia gelatin increased and the spectrum became broader, indicating that the gel network structure was denser and the system had better thermal stability.

[0056] In summary, after the κ-carrageenan and cassia gelatin powder are mixed in a mass ratio of 2:3 to 4:1, the prepared κ-carrageenan-cassia gelatin composite rubber has enhanced intermolecular hydrogen bonding force, and there is interaction between the two polysaccharides, resulting in the composite rubber having good gel strength, water retention and thermal stability; especially after the κ-carrageenan and cassia gelatin powder are mixed in a mass ratio of 6:4, the gel strength and water retention are optimal.

[0057] Example 2

[0058] (1) uniformly mixing κ-carrageenan and cassia gelatin powder in a mass ratio of 1.5:1 to form a mixture of κ-carrageenan and cassia gelatin powder;

[0059] (2) dispersing a mixture of κ-carrageenan and cassia gelatin powder at a concentration of 1.5 wt % in deionized water containing 0-1.0 wt % potassium chloride to prepare a dispersion;

[0060] (3) The dispersion was placed in a constant temperature water bath at 85°C and stirred for 30 min to obtain a composite gum of κ-carrageenan and cassia gum.

[0061] The gel strength diagram of the compound gel of κ-carrageenan and cassia gelatin with different potassium chloride contents, such as Figure 6 As shown in the figure, when the potassium chloride addition amount was in the range of 0-1.0wt%, the gel strength of κ-carrageenan-cassia gelatin increased first and then decreased. The addition of potassium chloride significantly improved the gel strength of κ-carrageenan-cassia gelatin and reached the maximum when the addition amount was 0.6wt%.

[0062] Example 3

[0063] (1) uniformly mixing κ-carrageenan and cassia gelatin powder in a mass ratio of 1.5:1 to form a mixture of κ-carrageenan and cassia gelatin powder;

[0064] (2) dispersing a mixture of κ-carrageenan and cassia gelatin powder at a concentration of 1.5 wt % in deionized water containing 0-1.0 wt % of sodium chloride to prepare a dispersion;

[0065] (3) The dispersion was placed in a constant temperature water bath at 85° C. and stirred for 30 min to obtain a composite gum of κ-carrageenan and cassia gum.

[0066] The gel strength diagram of the compound gel of κ-carrageenan and cassia gelatin with different sodium chloride contents, such as Figure 7 As shown. In the range of 0-1.0wt% of sodium chloride addition, the gel strength of κ-carrageenan-cassia gelatin first increased and then decreased. The addition of sodium chloride slightly increased the gel strength of κ-carrageenan-cassia gelatin and reached the maximum at an addition of 0.6wt%, which was smaller than that of potassium chloride.

[0067] Example 4

[0068] (1) uniformly mixing κ-carrageenan and cassia gelatin powder in a mass ratio of 1.5:1 to form a mixture of κ-carrageenan and cassia gelatin powder;

[0069] (2) dispersing a mixture of κ-carrageenan and cassia gelatin powder at a concentration of 1.5 wt % in deionized water containing 0-1.0 wt % of calcium chloride to prepare a dispersion;

[0070] (3) The dispersion was placed in a constant temperature water bath at 85°C and stirred for 30 min to obtain a composite gum of κ-carrageenan and cassia gum.

[0071] The gel strength diagram of the compound gel of κ-carrageenan and cassia gelatin with different calcium chloride contents, such as Figure 8 As shown. In the range of 0-1.0wt% calcium chloride addition, the gel strength of κ-carrageenan-cassia gelatin first increased and then decreased. The addition of calcium chloride slightly increased the gel strength of κ-carrageenan-cassia gelatin and reached the maximum at an addition of 0.4wt%. The increase was smaller than that of potassium chloride and larger than that of sodium chloride. However, when the concentration of calcium chloride was too high, the gelation was destroyed and the strength decreased.

[0072] Example 5

[0073] (1) uniformly mixing κ-carrageenan and cassia gelatin powder in a mass ratio of 1.5:1 to form a mixture of κ-carrageenan and cassia gelatin powder;

[0074] (2) dispersing a mixture of κ-carrageenan and cassia gelatin powder at a concentration of 1.5 wt % in deionized water containing 0.12 wt % potassium chloride, and adjusting the pH value of the system to 3 to 11 to prepare a dispersion;

[0075] (3) The dispersion was placed in a constant temperature water bath at 85°C and stirred for 30 min to obtain a composite gum of κ-carrageenan and cassia gum.

[0076] According to different pH values, the comparative gel strength results of compound gel and pure κ-carrageenan are as follows: Fig. 9 As shown. In the pH range of 4-11, the gel strength of κ-carrageenan-cassia gel (compounded gel) is higher than that of κ-carrageenan. The results show that κ-carrageenan-cassia gel has higher acid and alkali resistance. At the same time, in the pH range of 6-8, especially at pH 7, the gel strength of κ-carrageenan-cassia gel is optimal, and at pH 3, κ-carrageenan can no longer form a gel, but κ-carrageenan-cassia gel can still form a gel.

[0077] Example 6

[0078] (1) uniformly mixing κ-carrageenan and cassia gelatin powder in a mass ratio of 1.5:1 to form a mixture of κ-carrageenan and cassia gelatin powder;

[0079] (2) dispersing a mixture of κ-carrageenan and cassia gelatin powder at concentrations of 0.5 wt %, 1.5 wt % and 2.0 wt % in deionized water containing 0.04 wt %, 0.12 wt % and 0.16 wt % of potassium chloride, respectively, to prepare dispersions;

[0080] (3) The dispersion was placed in a constant temperature water bath at 85°C and stirred for 30 min to obtain a composite gum of κ-carrageenan and cassia gum.

[0081] Example 7

[0082] (1) uniformly mixing κ-carrageenan and cassia gelatin powder in a mass ratio of 1.5:1 to form a mixture of κ-carrageenan and cassia gelatin powder;

[0083] (2) dispersing a mixture of κ-carrageenan and cassia gelatin powder at a concentration of 1.5 wt % in deionized water containing 0.12 wt % potassium chloride to prepare a dispersion;

[0084] (3) The dispersion was placed in a constant temperature water bath at 75-95° C. and stirred for 30 min to obtain a composite gum of κ-carrageenan and cassia gum.

[0085] Example 8

[0086] (1) uniformly mixing κ-carrageenan and cassia gelatin powder in a mass ratio of 1.5:1 to form a mixture of κ-carrageenan and cassia gelatin powder;

[0087] (2) dispersing a mixture of κ-carrageenan and cassia gelatin powder at a concentration of 1.5 wt % in deionized water containing 0.12 wt % potassium chloride to prepare a dispersion;

[0088] (3) The dispersion was placed in a constant temperature water bath at 85° C. and stirred for 20-50 min to obtain a composite gum of κ-carrageenan and cassia gum.

[0089] The test results of gel strength of the compound adhesives prepared in Examples 6 to 8 above are shown in Table 1:

[0090] Table 1 Gel strength of compound gel of κ-carrageenan and cassia gum

[0091]

[0092]

[0093] The results are shown in Table 1. The κ-carrageenan-cassia gum composite gel prepared by the method of the present invention has a linear effect on the gel strength. The higher the composite gel concentration, the greater the gel strength. Too low a composite gel concentration (0.5%) will result in low gel strength, and too high a composite gel concentration (2.0%) will result in difficulty in dispersion. Therefore, the optimal concentration is 1.5%.

[0094] At different stirring temperatures, the dissolution was incomplete when the temperature was too low (75°C), and the sample was slightly degraded when the temperature was too high (95°C), so the optimal stirring temperature was 85°C. At different stirring times, too short a stirring time (20 min) would lead to incomplete dissolution, and too long a stirring time (50 min) would lead to sample degradation and decreased gel strength, so the optimal stirring time was 30 min.

[0095] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0096] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0097] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for preparing a compound rubber, characterized in that: The following steps are involved: (1) mixing κ-carrageenan powder and cassia gelatin powder in a mass ratio of 2:3-4:1 to obtain a mixed powder of κ-carrageenan and cassia gelatin; (2) dispersing the mixed powder in deionized water containing salt to obtain a dispersion, and adjusting the pH value of the system in the dispersion; (3) placing the dispersion in a constant temperature water bath for stirring to obtain a compound rubber product.

2. The method for preparing a compound rubber according to claim 1, characterized in that: In step (1), the κ-carrageenan powder and the Cassia gelatin powder are evenly mixed in a mass ratio of 3:

2.

3. A method for preparing a compound rubber according to claim 2, characterized in that: In step (2), the salt comprises at least one of potassium chloride, sodium chloride or calcium chloride.

4. The method for preparing a compound rubber according to claim 3, characterized in that: In step (2), the concentration of the salt is 0.1-1.0 wt %.

5. A method for preparing a compound rubber according to claim 3 or 4, characterized in that: In step (2), the potassium chloride has a concentration of 0.6 wt%.

6. A method for preparing a compound rubber according to claim 3 or 4, characterized in that: In step (2), the concentration of sodium chloride is 0.6 wt %; or the concentration of calcium chloride is 0.4 wt %.

7. The method for preparing a compound rubber according to claim 5, characterized in that: In step (2), the pH value is 4-11, preferably 6-7.

8. The method for preparing a compound rubber according to claim 2, characterized in that: In step (2), the concentration of the mixed powder in the dispersion is 0.5-2.0 wt %, preferably 1.5 wt %.

9. The method for preparing a compound rubber according to claim 8, characterized in that: In step (3), the temperature of the constant temperature water bath is 75-95° C., and the stirring time is 20-50 min.

10. A compound adhesive, characterized in that: The compound adhesive prepared by the method according to any one of claims 1 to 9 has a gel strength of 1000 to 1960 g / cm 2 ; The thermal stability of the compound rubber is improved compared with κ-carrageenan; the water retention index is that the dehydration rate of the compound rubber is 17.48%-31.04%.

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