Konjac mannan oligosaccharide-starch compound obtained by one-step extrusion method

Abstract

The invention discloses a konjak mannan oligosaccharide-starch compound obtained by a one-step extrusion method, and a preparation method comprises the following steps: (1) extruding starch and konjak mannan oligosaccharide by a twin-screw extruder after the water content of a material in the extruder is 40-60wt%, gelatinizing and melting the starch and blending the starch with the konjak mannan oligosaccharide to obtain the konjak mannan oligosaccharide-starch compound. The addition mass of the konjac mannan oligosaccharide is 4%-12% of the mass of the dry basis of the starch. And (2) extruding the blend of the starch and the konjac mannan oligosaccharide obtained in the step (1) by using relatively strong material pushing and pressure building capabilities of a single screw to form the konjac mannan oligosaccharide-starch compound. According to the method for preparing the konjak mannan oligosaccharide-starch compound through the one-step reaction type extrusion method, the konjak mannan oligosaccharide-starch compound with high content of anti-digestion starch is obtained through the double-screw extrusion-compounding-single-screw extrusion-forming method, and the digestion performance of the starch is remarkably reduced.

Description

Technical Field

[0001] The invention relates to the technical field of functional foods, in particular to a konjac mannan oligosaccharide-starch complex obtained by a one-step extrusion method. Background Art

[0002] Obesity is closely related to nutritional metabolic disorders, insulin resistance, and especially inflammation. Under inflammatory stimulation, it is not only related to inflammation, apoptosis and necrosis, but also associated with the occurrence of mammalian obesity at the genetic level. One of the characteristics of obesity is the accumulation of triglycerides and fat droplets in the internal organs, which also increases the risk of patients suffering from type 2 diabetes. In an obese body, adipose tissue secretes a large amount of pro-inflammatory and anti-inflammatory cytokines, which not only causes systemic chronic inflammation in the body, but also adipose tissue macrophage infiltration exacerbates the degree of chronic low-grade inflammation. In an overly obese body, white fat cells expand excessively, causing local tissue hypoxia and necrosis, which in turn causes a variety of metabolic inflammations.

[0003] Currently, the treatment of obesity is mainly based on Western medicine. Western medicine is effective in treating obesity and has a significant effect in alleviating obesity, but its efficacy is limited, it has obvious toxic side effects on the body, cannot eliminate obesity complications, and some Western medicines are expensive. Therefore, the search for dietary ingredients that can alleviate obesity has attracted increasing attention from scholars around the world.

[0004] According to the digestion rate, starch can be divided into rapidly digestible starch (RDS), slowly digestible starch (SDS) and resistant starch (RS). RS cannot be digested in the small intestine, but is fermented and degraded by intestinal flora in the colon to produce short-chain fatty acids and gas. RS plays a key role in promoting a variety of health-promoting effects, including lowering blood sugar and cholesterol, inhibiting body fat accumulation, increasing mineral absorption, and preventing obesity. Konjac mannan oligosaccharide-starch complex is a single helical V-shaped complex formed by starch and konjac mannan oligosaccharide when heated and cooled, and is a RS5-type resistant starch. At present, the preparation of RS5-type resistant starch generally faces the problems of low yield and high energy consumption. In summary, the invention of a new strategy to improve the preparation efficiency of konjac mannan oligosaccharide-starch complex is of great significance for the industrial production of RS5-type resistant starch. Summary of the invention

[0005] In order to solve the above-mentioned deficiencies in the prior art, the present invention proposes a konjac mannan oligosaccharide-starch complex obtained by a one-step extrusion method.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solution: a konjac mannan oligosaccharide-starch complex obtained by a one-step extrusion method, the preparation method comprising the following steps:

[0007] (1) The moisture content of the material in the extruder is 40-60wt%, and the starch and konjac manno oligosaccharide are extruded by a twin-screw extruder, and the starch is gelatinized and melted and blended with the konjac manno oligosaccharide to obtain a blend of starch and konjac manno oligosaccharide, wherein the added mass of the konjac manno oligosaccharide is 4%-12% of the dry mass of the starch.

[0008] (2) The starch and konjac oligosaccharide blend obtained in step (1) is extruded into a konjac oligosaccharide-starch composite by utilizing the strong material pushing and pressure building capabilities of a single screw.

[0009] Furthermore, in the step (1), the rotation speed of the twin-screw extruder is 100-250 rpm; the temperature of the 12 temperature zones in the extruder is increased sequentially, and the temperature zone is 35-120°C.

[0010] Furthermore, in step (1), the temperatures of the twelve temperature zones of the extruder are: 35-40°C for zones 1 to 4, 50-80°C for zones 5 to 9, and 90-120°C for zones 10 to 12.

[0011] Furthermore, in the step (2), the water content of the material is 40-60wt%, and the gelatinization degree of the extrudate is greater than 90%.

[0012] Furthermore, in the step (2), the rotation speed of the single screw extruder is 150-300 rpm; the temperatures of the three temperature zones in the extruder are increased sequentially, and the temperature zone of the extruder is 50-100°C.

[0013] Furthermore, in step (2), the temperatures of the three temperature zones of the extruder are: zone 1 temperature 50-60°C, zone 2 temperature 70-80°C, zone 3 temperature 90-100°C.

[0014] Furthermore, the starch in step (1) includes rice starch or tapioca starch.

[0015] Furthermore, the konjac mannan oligosaccharide-starch complex is used in food and medicine.

[0016] Furthermore, a konjac mannan oligosaccharide-starch complex having the effects of resisting obesity and reducing obesity-related inflammation is used in the preparation of animal medical drugs.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) The method for preparing konjac mannan oligosaccharide-starch composite by a one-step reactive extrusion method of the present invention utilizes a twin-screw extrusion-compounding-single-screw extrusion-molding method to obtain a konjac mannan oligosaccharide-starch composite with a high content of digestion-resistant starch, which significantly reduces the digestibility of starch.

[0019] (2) The preparation process of the konjac mannan oligosaccharide-starch complex prepared by the present invention is simplified, the problems of low starch concentration, long processing time and complex preparation process in the preparation of the konjac mannan oligosaccharide-starch complex are solved, the preparation efficiency of the complex is significantly improved, and the extrusion preparation of the konjac mannan oligosaccharide-starch complex is realized.

[0020] (3) The konjac oligosaccharide-starch complex of the present invention effectively enhances the weight loss effect. The experimental results show that the complex prepared by the present invention has a significant synergistic effect in improving the degree of liver fatty degeneration, reducing white fat accumulation in the epididymis, lowering blood lipid levels, and improving oxidative stress. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a scanning electron micrograph of konjac mannan oligosaccharide-starch complex.

[0022] Figure 2 This is the small angle X-ray diffraction pattern of konjac mannan oligosaccharide-starch complex.

[0023] Figure 3 This is the short-range order diagram of konjac mannan oligosaccharide-starch complex.

[0024] Figure 4 This is the solid 13C NMR diagram of konjac mannan oligosaccharide-starch complex.

[0025] Figure 5 This is the X-ray diffraction pattern of konjac mannan oligosaccharide-starch complex.

[0026] Figure 6 It is a graph showing the weight changes of mice in each experimental group of the present invention.

[0027] Figure 7 It is the HE staining picture of the liver tissue of mice in each experimental group of the present invention.

[0028] Figure 8 It is the HE staining picture of epididymal white adipose tissue of each experimental group of mice in the present invention.

[0029] Fig. 9 It is a schematic diagram of the effects of the experimental groups of the present invention on the blood lipid levels of mice.

[0030] Fig.10 It is a schematic diagram of the effects of the experimental groups of the present invention on the oxidative stress level of mouse liver. DETAILED DESCRIPTION

[0031] The invention is described in detail below with reference to the embodiments.

[0032] Example 1

[0033] A konjac mannooligosaccharide-starch complex obtained by a one-step extrusion method comprises the following steps:

[0034] (1) ordinary rice starch and konjac oligosaccharide are mixed, the addition amount of konjac oligosaccharide is 4% of the mass of ordinary rice starch, and added to the feeding end of a twin-screw extruder, the material water content is set to 40wt%, the screw speed is 150rpm, the temperature of the twin-screw extruder in zones 1 to 4 is set to 35°C, the temperature of zones 5 to 9 is set to 80°C, and the temperature of zones 10 to 12 is set to 120°C, and extrusion is started;

[0035] (2) The mixture extruded in step (1) is conveyed to the feeding end of a single screw extruder, and the moisture content of the feed is set to 60 wt %; the temperature of the first zone of the extruder is set to 55° C., the temperature of the second zone is set to 75° C., the temperature of the third zone is set to 95° C., the screw speed is 150 rpm, and extrusion is started, and the extruded konjac oligosaccharide-starch complex is collected and dried and crushed.

[0036] Example 2

[0037] A konjac mannooligosaccharide-starch complex obtained by a one-step extrusion method comprises the following steps:

[0038] (1) ordinary rice starch and konjac oligosaccharide are mixed, the addition amount of konjac oligosaccharide is 4% of the mass of ordinary rice starch, and added to the feeding end of a twin-screw extruder, the material water content is set to 40wt%, the screw speed is 150rpm, the temperature of the twin-screw extruder in zones 1 to 4 is set to 40°C, the temperature of zones 5 to 9 is set to 75°C, and the temperature of zones 10 to 12 is set to 115°C, and extrusion is started;

[0039] (2) The mixture extruded in step (1) is conveyed to the feeding end of a single screw extruder, and the water content of the feed is set to 60 wt %; the temperature of the first zone of the extruder is set to 50° C., the temperature of the second zone is set to 70° C., the temperature of the third zone is set to 90° C., the screw speed is 150 rpm, and extrusion is started, and the extruded konjac oligosaccharide-starch complex is collected and dried and crushed.

[0040] Example 3

[0041] A konjac mannooligosaccharide-starch complex obtained by a one-step extrusion method comprises the following steps:

[0042] (1) ordinary rice starch and konjac oligosaccharide are mixed, the addition amount of konjac oligosaccharide is 4% of the mass of ordinary rice starch, and added to the feeding end of a twin-screw extruder, the material water content is set to 40wt%, the screw speed is 150rpm, the temperature of the twin-screw extruder in zones 1 to 4 is set to 35°C, the temperature of zones 5 to 9 is set to 75°C, and the temperature of zones 10 to 12 is set to 110°C, and extrusion is started;

[0043] (2) The mixture extruded in step (1) is conveyed to the feeding end of a single screw extruder, and the moisture content of the feed is set to 60 wt %; the temperature of the first zone of the extruder is set to 60° C., the temperature of the second zone is set to 80° C., the temperature of the third zone is set to 90° C., the screw speed is 150 rpm, and extrusion is started, and the extruded konjac oligosaccharide-starch complex is collected and dried and crushed.

[0044] Comparative Example 1

[0045] Add ordinary rice starch to the feeding end of a twin-screw extruder, set the moisture content of the material to 40wt%, the screw speed to 150rpm, set the temperature of the first to fourth zones of the twin-screw extruder to 35°C, the temperature of the fifth to ninth zones to 80°C, the temperature of the tenth to twelve zones to 120°C, and start extrusion, collect the extrudate, dry and grind it at 45°C, and pass it through a 60-mesh sieve to obtain the product.

[0046] Comparative Example 2

[0047] (1) adding common rice starch to the feeding end of a twin-screw extruder, setting the material water content to 40 wt %, the screw speed to 150 rpm, the temperature of the twin-screw extruder zones 1 to 4 to 35° C., the temperature of the zones 5 to 9 to 80° C., the temperature of the zones 10 to 12 to 120° C., and starting extrusion;

[0048] (2) The mixture extruded in step (1) is conveyed to the feeding end of a single screw extruder, and the moisture content of the feed is set to 60 wt %; the temperature of the first zone of the extruder is set to 55° C., the temperature of the second zone of the extruder is set to 75° C., the temperature of the third zone is set to 95° C., the screw speed is 150 rpm, and extrusion is started. The extrudate is collected and dried at 45° C., crushed and passed through a 60-mesh sieve.

[0049] Experimental methods:

[0050] Experiment 1

[0051] Male C57BL / 6J mice were purchased from the Experimental Animal Research Center of Hainan Medical University at 6 to 7 weeks of age. After 2 weeks of adaptation, they were fed a high-fat diet (HFD) containing 60% kcal of fat to establish an obese animal model. Compared with mice fed a healthy diet, obese mice with a body weight increase of more than 20% were selected for the following test: obese mice (10 per group) were orally given a konjac manno oligosaccharide-starch complex solution (containing 45 mg konjac manno oligosaccharide-starch) and a high-fat diet (HFD) containing 60% kcal of fat once a day for 8 weeks. The control group was fed a normal chow diet (NCD) and saline. The body weight, food consumption, and energy expenditure of each mouse were recorded throughout the study. After the last week of the experiment, the mice were killed, adipose tissue was collected, and the adipose tissue was weighed. The liver and epididymal white adipose tissue of mice were collected, fixed with 10% formalin, sliced, embedded in paraffin, and stained with HE to make slices, observed and photographed under an optical inverted microscope. The collected blood was centrifuged (10000r / min, 10min), and the supernatant was serum, which was stored at low temperature. The TC, TG, LDL-C, and HDL-C levels in the serum were determined according to the instructions of the kit. The mouse liver was ground with physiological saline to make a 10% homogenate, centrifuged (4000r / min, 10min), and the MDA, SOD, and GSH-Px levels in the liver were determined according to the instructions of the kit.

[0052] After oral administration of 45 mg of the konjac oligosaccharide-starch complex prepared in Example 1 once a day for 8 weeks, the average body weight of the mice decreased from 35.68 g to 32.73 g, with an average weight loss of 8.3% (see Appendix Figure 6 ), although still fed with a high-fat diet, the weight of obese mice was close to that of normal mice. After daily administration of 45 mg of the konjac oligosaccharide-starch complex prepared in Example 1 for 8 weeks, the liver tissue of mice was well repaired, the hepatic cords were neatly arranged, and there were fewer vacuoles in the cytoplasm (see Appendix Figure 7 After daily administration of 45 mg of the konjac oligosaccharide-starch complex prepared in Example 1 for 8 weeks, the epididymal adipocytes of mice were reduced (appendix Figure 8 After daily administration of 45 mg of the konjac oligosaccharide-starch complex prepared in Example 1 for 8 weeks, the serum TC, TG, and LDL-C levels of mice were significantly reduced, while the HDL-C level was significantly increased (see Appendix). Fig. 9 After daily administration of 45 mg of the konjac oligosaccharide-starch complex prepared in Example 1 for 8 weeks, the contents of SOD and GSH-Px were increased, while the content of MDA was decreased (see Appendix). Fig.10). Based on the above data, it is shown that after daily administration of 45 mg of the konjac oligosaccharide-starch complex prepared in Example 1 for 8 weeks, the overall level of inflammation associated with obesity is alleviated to a certain extent.

[0053] Experiment 2

[0054] Male C57BL / 6J mice were purchased from the Experimental Animal Research Center of Hainan Medical University. After 2 weeks of adaptation, they were fed a high-fat diet (HFD) containing 60% kcal of fat to establish an obese animal model. Compared with mice fed a healthy diet, obese mice with a weight increase of more than 20% were selected for the following test: obese mice (10 per group) were orally given the extrudate solution prepared in Comparative Example 2 (containing 45 mg of the extrudate prepared in Comparative Example 2) and a high-fat diet (HFD) containing 60% kcal of fat once a day for 8 weeks. The control group was fed with a normal chow diet (NCD) and saline. During the entire study, the weight, food consumption and energy consumption of each mouse were recorded. After the last week of the experiment, the mice were killed, adipose tissue was collected, and the adipose tissue was weighed. After the liver and epididymal white adipose tissue of the mice were taken, they were fixed with 10% formalin, sliced, embedded in paraffin, and HE stained to make slices, observed and photographed by an optical inverted microscope. The collected blood was centrifuged (10000r / min, 10min), and the supernatant was serum, which was stored at low temperature. The TC, TG, LDL-C, and HDL-C levels in the serum were determined according to the kit instructions. The mouse liver was ground with physiological saline to make a 10% homogenate, centrifuged (4000r / min, 10min), and the MDA, SOD, and GSH-Px levels in the liver were determined according to the kit instructions.

[0055] After oral administration of 45 mg of the extrudate prepared in Comparative Example 2 once a day for 8 weeks, the average body weight of the mice continued to increase, with the highest body weight group (see Appendix Figure 6 ), the weight of the mice was close to that of obese mice. After oral administration of 45 mg of the extrudate prepared in Comparative Example 2 once a day for 8 weeks, the liver tissue of the mice was well repaired, the hepatic cords were neatly arranged, and there were fewer vacuoles in the cytoplasm (see Figure 7 After oral administration of 45 mg of the extrudate prepared in Comparative Example 2 once a day for 8 weeks, the epididymal adipocytes of mice were reduced, but the effect was significantly lower than that of the konjac mannooligosaccharide-starch complex prepared in Example 1 (Appendix Figure 8 ). After oral administration of 45 mg of the extrudate prepared in Comparative Example 2 once a day for 8 weeks, the levels of TC, TG, and LDL-C in the serum of mice were reduced, while the level of HDL-C was increased, but the effect was significantly lower than that of the konjac mannooligosaccharide-starch complex prepared in Example 1 (Appendix Fig. 9). After oral administration of 45 mg of the extrudate prepared in Comparative Example 2 once a day for 8 weeks, the contents of SOD and GSH-Px were increased, while the content of MDA was reduced, but the effect was significantly lower than that of the konjac oligosaccharide-starch complex prepared in Example 1 (see Appendix). Fig.10 ). Based on the above data, it can be seen that oral administration of 45 mg of the extrudate prepared in Comparative Example 2 once a day for 8 weeks can alleviate the overall level of inflammation associated with obesity to a certain extent, but the effect is significantly lower than that of the konjac mannan oligosaccharide-starch complex prepared in Example 1.

[0056] The content of digestion-resistant starch in each embodiment and comparative example sample was measured using the Englyst in vitro simulated digestion method. The results are shown in Table 1. As can be seen from Table 1, when the content of konjac mannan oligosaccharide is 4%, the content of digestion-resistant starch in the composite is 35.13%. As the content of konjac mannan oligosaccharide increases to 8%, the content of digestion-resistant starch in the composite increases to 41.14%, which is much higher than the content of digestion-resistant starch in ordinary rice starch and rice starch after extrusion.

[0057] Table 1 Contents of fast digestible starch, slow digestible starch and resistant starch in samples

[0058] sample Fast digestible starch (%) Slowly digestible starch (%) Digestion-resistant starch (%) Rice starch <![CDATA[95.00±0.20 f ]]> <![CDATA[3.50±1.10 a ]]> <![CDATA[1.50±0.90 a ]]> Comparative Example 1 <![CDATA[86.70±0.10 e ]]> <![CDATA[5.30±0.20 b ]]> <![CDATA[8.00±0.40 b ]]> Comparative Example 2 <![CDATA[82.20±0.30 d ]]> <![CDATA[6.60±0.10 c ]]> <![CDATA[11.20±0.10 c ]]> Example 1 <![CDATA[48.06±0.92 c ]]> <![CDATA[16.81±1.10 d ]]> <![CDATA[35.13±0.89 d ]]> Example 2 <![CDATA[39.23±1.13 b ]]> <![CDATA[22.57±1.21 e ]]> <![CDATA[38.19±1.10 e ]]> Example 3 <![CDATA[36.47±1.14 a ]]> <![CDATA[22.39±1.01 e ]]> <![CDATA[41.14±1.14 f ]]>

[0059] Note: a, b, c have different letters, indicating that there are significant differences among the data groups, p<0.05.

[0060] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the patent and protection scope of the present invention shall be subject to the attached claims.

Claims

1. A konjac oligosaccharide-starch complex obtained by a one-step extrusion method, characterized in that: The preparation method comprises the following steps: (1) The moisture content of the material in the extruder is 40-60wt%, and the starch and konjac manno oligosaccharide are extruded by a twin-screw extruder, and the starch is gelatinized and melted and blended with the konjac manno oligosaccharide to obtain a blend of starch and konjac manno oligosaccharide, wherein the added mass of the konjac manno oligosaccharide is 4%-12% of the dry mass of the starch. (2) The starch and konjac oligosaccharide blend obtained in step (1) is extruded into a konjac oligosaccharide-starch composite by utilizing the strong material pushing and pressure building capabilities of a single screw.

2. The konjac oligosaccharide-starch complex obtained by a one-step extrusion method according to claim 1, characterized in that: In the step (1), the rotation speed of the twin-screw extruder is 100-250 rpm; the temperature of the 12 temperature zones in the extruder is increased sequentially, and the temperature zone is 35-120°C.

3. The konjac oligosaccharide-starch complex obtained by a one-step extrusion method according to claim 2, characterized in that: In step (1), the temperatures of the twelve temperature zones of the extruder are: 35-40°C for zones 1 to 4, 50-80°C for zones 5 to 9, and 90-120°C for zones 10 to 12.

4. The konjac oligosaccharide-starch complex obtained by a one-step extrusion method according to claim 1, characterized in that: In the step (2), the water content of the material is 40-60wt%, and the gelatinization degree of the extrudate is greater than 90%.

5. The konjac oligosaccharide-starch complex obtained by a one-step extrusion method according to claim 4, characterized in that: In the step (2), the rotation speed of the single-screw extruder is 150-300 rpm; the temperatures of the three temperature zones in the extruder are increased sequentially, and the temperature zones of the extruder are 50-100°C.

6. The konjac oligosaccharide-starch complex obtained by a one-step extrusion method according to claim 5, characterized in that: In step (2), the temperatures of the three temperature zones of the extruder are: zone 1 temperature 50-60°C, zone 2 temperature 70-80°C, zone 3 temperature 90-100°C 7. The konjac oligosaccharide-starch complex obtained by a one-step extrusion method according to claim 1, characterized in that: The starch in step (1) includes rice starch or tapioca starch.

8. Use of the konjac mannooligosaccharide-starch complex as claimed in claims 1 to 7 in food and medicine.

9. Use of the konjac mannan oligosaccharide-starch complex having anti-obesity and obesity-related inflammation-reducing properties as claimed in claims 1 to 7 in the preparation of veterinary medicine.

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