A pectin short-chain fatty acid ester composition, and a preparation method and application thereof

Abstract

The present application relates to appetite suppressant technical field, provide a kind of pectin short-chain fatty acid ester composition and its preparation method and application.The composition provided by the present application includes pectin short-chain fatty acid ester 40-96% and metal compound 4-60%.The present application uses pectin as the carrier of short-chain fatty acid, and is combined with metal compound, pectin can be combined with multivalent metal cation in stomach, improve chyme viscosity, delay gastric emptying, improve meal satiety, help reduce meal intake;At the same time, pectin short-chain fatty acid ester can persist and directional release short-chain fatty acid in vivo, extend satiety time, so as to more effectively reduce appetite.Above all, the composition provided by the present application is synergized by multiple mechanisms, and functions in stomach and colon part, can more effectively inhibit appetite, help reduce food intake, has great potential in weight management, obesity treatment and control postprandial blood glucose rise etc..

Description

Technical Field

[0001] This invention relates to the field of appetite suppressant technology, and more particularly to a pectin short-chain fatty acid ester composition, its preparation method, and its application. Background Technology

[0002] In recent years, obesity has become a serious global health challenge. Even small weight loss, such as 10% of initial body weight, can reduce risk factors such as high blood pressure, high cholesterol, and high blood sugar in overweight and obese adults. The causes of obesity are complex and multifactorial, and mounting evidence suggests that it is not simply a matter of self-control, but a complex disease involving appetite regulation and energy metabolism. Although the exact causes of obesity are not fully understood, genetic, metabolic, biochemical, cultural, and psychosocial factors are believed to play a role.

[0003] Currently, appetite control and thus reducing food intake are attractive strategies for weight management in overweight and obesity. Soluble dietary fiber, such as pectin, guar gum, and some low-molecular-weight non-starch polysaccharides, is also believed to reduce the digestibility of food in the stomach, enhance satiety, lower cholesterol, and regulate postprandial glycemic response. Soluble dietary fiber can enhance satiety and improve postprandial glycemic response by increasing the viscosity of gastric contents. Amide-modified pectin (low-ester pectin) and some polyvalent metal cations can form a gel with a viscosity far exceeding that of pure pectin in the acidic environment of the stomach through a "bridging reaction" or "egg carton model," thereby greatly increasing the viscosity of chyme in the stomach, delaying gastric emptying, maintaining gastric distension for a longer period, and achieving the effects of increasing satiety and reducing postprandial glycemic response. JC Richardson et al.'s patent (CN101631476A) provides a composition combining pectin and polyvalent cations that can form a gel resistant to peristalsis and maintained in the stomach for a long time in an aqueous medium and in the acidic environment of the stomach, thus achieving a satiety effect. However, the composition in this patent requires hydration before entering the stomach, which increases the complexity of eating to some extent. At the same time, in this case, the short-chain fatty acid esters produced by pectin in the intestine are limited, and the satiating effect is mainly in the stomach, so the appetite suppression effect is not good.

[0004] Currently, dietary fiber, whether soluble or insoluble, is commonly used in food products and is frequently claimed to slow gastric emptying, increase satiety, and control postprandial blood sugar. However, due to limitations in the amount added and the underlying mechanism, its effectiveness is very limited, and many food products have not undergone research verification.

[0005] Short-chain fatty acids (SCFAs), including acetic acid, propionic acid, and butyric acid, are metabolic products of soluble dietary fiber in the colon and play an important role in regulating appetite and weight. However, SCFAs alone are easily broken down before reaching the colon, making it difficult to achieve the goals of reducing appetite and decreasing energy intake.

[0006] In summary, current appetite suppressants cannot achieve multi-faceted, rapid, and long-lasting appetite suppression effects. There is an urgent need to develop an appetite suppressant that can both delay food emptying in the stomach and stimulate the intestines to produce appetite-suppressing hormones to a greater extent, thereby achieving more effective appetite suppression, weight loss, and even reducing postprandial blood glucose response. Summary of the Invention

[0007] In view of this, the present invention provides a pectin short-chain fatty acid ester composition, its preparation method, and its applications. The pectin short-chain fatty acid ester composition provided by the present invention can both delay food emptying in the stomach and stimulate the intestine to produce appetite-suppressing hormones to a greater extent, thereby achieving multi-faceted, rapid, and long-lasting appetite suppression. It has broad application prospects in weight management, obesity treatment, and blood sugar reduction.

[0008] To achieve the above-mentioned objectives, the present invention provides the following technical solution: A pectin short-chain fatty acid ester composition comprising the following components in weight percentage: 40-96% pectin short-chain fatty acid ester and 4-60% metal compound.

[0009] Preferably, the short-chain fatty acid units in the pectin short-chain fatty acid ester have a mass percentage content of 10% to 60%.

[0010] Preferably, the degree of substitution of the short-chain fatty acids in the pectin short-chain fatty acid ester is 0.2 to 1; and the degree of esterification of the pectin is less than 50%.

[0011] Preferably, the method for preparing the pectin short-chain fatty acid ester includes: Pectin, an esterifying agent, and a solvent are mixed and subjected to an esterification reaction to obtain the pectin short-chain fatty acid ester; the esterifying agent is at least one of short-chain fatty acids and short-chain fatty acid anhydrides.

[0012] Preferably, the esterifying agent is a short-chain fatty acid anhydride, and the molar ratio of the short-chain fatty acid anhydride to pectin is (1~5.5):1; the esterification reaction temperature is 30~65℃, and the time is 10~18h.

[0013] Preferably, after the esterification reaction is completed, the resulting reaction solution is further purified to obtain pectin short-chain fatty acid esters; the purification process includes: washing, extracting, concentrating and drying the resulting reaction solution in sequence to obtain purified pectin short-chain fatty acid esters; the extraction includes sequential organic solvent extraction, saturated sodium chloride solution extraction and saturated sodium bicarbonate solution extraction; the organic solvent used for the organic solvent extraction is ethyl acetate or dichloromethane.

[0014] Preferably, the metal compound includes one or more of a metal salt and a metal oxide; the metal cation in the metal compound includes Ca. 2+ Mg 2+ Zn 2+ Cu 2+ Al 3+ and Fe 3+ One or more of them.

[0015] The present invention also provides a method for preparing the pectin short-chain fatty acid ester composition described above, comprising the following steps: A portion of pectin short-chain fatty acid esters and a metal compound are first mixed to obtain a premix; the mass ratio of the portion of pectin short-chain fatty acid esters to the metal compound is (1~3):1. The premix and the remaining portion of the pectin short-chain fatty acid esters are mixed a second time to obtain the pectin short-chain fatty acid ester composition.

[0016] The present invention also provides the use of the pectin short-chain fatty acid ester composition described in the above-described scheme or the pectin short-chain fatty acid ester composition prepared by the preparation method described in the above-described scheme in the preparation of animal feed or in the preparation of a drug; the drug includes a drug for treating obesity or a drug for lowering blood sugar.

[0017] The present invention also provides an appetite suppressant product, comprising the pectin short-chain fatty acid ester composition described in the above-described scheme or the pectin short-chain fatty acid ester composition prepared by the preparation method described in the above-described scheme; the dosage form of the appetite suppressant product is powder, liquid preparation, capsule or tablet.

[0018] This invention provides a pectin short-chain fatty acid ester composition comprising the following components in weight percentage: 40-96% pectin short-chain fatty acid ester and 4-60% metal compound. The beneficial effects of this invention are as follows: The composition of this invention includes pectin short-chain fatty acid esters, which are obtained by combining pectin and short-chain fatty acids (or acid anhydrides) through ester bonds. Pectin short-chain fatty acid esters are not decomposed in the stomach or upper digestive tract, but can only be decomposed by bacterial fermentation in the intestine. After pectin is decomposed by microorganisms in the intestine, it can release short-chain fatty acids, thereby ensuring the release rate of short-chain fatty acids. Moreover, the decomposition of pectin in the intestine can also ferment to generate some short-chain fatty acids, ensuring that more short-chain fatty acids reach the intestine, stimulating the secretion of more satiety-related hormones, such as GLP-1 and PPY, thereby enhancing satiety to a greater extent. At the same time, pectin short-chain fatty acid esters can also retain the role of pectin as a water-soluble dietary fiber in slowing down the rate of food emptying in the stomach.

[0019] This invention combines pectin short-chain fatty acid esters with metal cations to achieve a multi-mechanism appetite-suppressing effect: the composition exerts its appetite-suppressing effect through different mechanisms in both the upper and lower digestive tracts. The bridging reaction between pectin and metal cations in the stomach increases chyme viscosity, delays gastric emptying, and enhances the feeling of fullness in the stomach. The targeted release of short-chain fatty acids in the intestine induces the secretion of appetite-suppressing hormones. The synergistic effect of these multiple mechanisms makes pectin short-chain fatty acid esters, compared to single short-chain fatty acid esters or inulin short-chain fatty acid esters, a more effective appetite suppressant. In summary, the composition provided by this invention can exert its effects in both the stomach and intestines, providing both immediate gastric and long-term intestinal appetite-suppressing effects.

[0020] The composition of this invention is water-soluble and can also be used as a powder in various forms, such as solid beverages, capsules, and tablets. Pectin itself is a natural food ingredient widely used in the food industry. It has greater health value in improving insulin sensitivity and inhibiting postprandial blood sugar spikes. As a derivative of pectin, pectin short-chain fatty acid esters not only have the effect of suppressing appetite but also have the potential to control type 2 diabetes. Furthermore, pectin short-chain fatty acid esters have a low lipoprotein content, which is very beneficial for energy intake control during weight loss without adding extra weight loss burden, making them more suitable for long-term appetite regulation and weight management.

[0021] Animal experiments and human trials in the embodiments of the present invention show that, with the same dietary fiber content, the composition of the present invention can stimulate the production of more appetite-suppressing hormones and reduce food intake. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the preparation process of the pectin short-chain fatty acid ester of the present invention; Figure 2 This is a schematic diagram of the preparation process of the pectin short-chain fatty acid ester composition of the present invention; Figure 3The viscosity changes of test samples 1-4 in Example 3; Figure 4 The total SCFA (acetic acid, propionic acid, butyric acid) content of the three culture media in Example 4 after in vitro fermentation for 36 hours; Figure 5 The composition of short-chain fatty acids produced after in vitro fermentation of the three culture media in Example 4 for 36 hours; Figure 6 The change in mouse body weight before and after 4 weeks of intervention in Example 5; Figure 7 The content of short-chain fatty acids in mouse feces after 4 weeks of intervention in Example 5; Figure 8 Serum PPY levels in mice of each group after 4 weeks of intervention; Figure 9 Serum GLP-1 levels in mice of each group after 4 weeks of intervention; Figure 10 The VAS scores for hunger, satiety, expected food intake, satiety, and total appetite suppression scores for each group in Example 6 over time. Figure 11 The following are the blood glucose increase curves after eating in each group in Example 6; Figure 12 This represents the increase in the area under the blood glucose response curve after each group in Example 6. Detailed Implementation

[0023] The present invention provides a pectin short-chain fatty acid ester composition comprising the following components in weight percentage: 40-96% pectin short-chain fatty acid ester and 4-60% metal compound.

[0024] Unless otherwise specified, all raw materials used in this invention are commercially available.

[0025] The pectin short-chain fatty acid ester composition provided by this invention comprises 40-96% pectin short-chain fatty acid ester, preferably 50-90%, by weight percentage. In this invention, the weight percentage of short-chain fatty acid units in the pectin short-chain fatty acid ester is preferably 10%-60%, more preferably 20%-50%; the degree of substitution of the short-chain fatty acids in the pectin short-chain fatty acid ester is preferably 0.2-1, more preferably 0.25-0.9, and even more preferably 0.3-0.8. Specifically, the degree of substitution of the short-chain fatty acids refers to the number of active hydroxyl groups on the pectin D-glucose unit that are replaced by short-chain fatty acids. In this invention, the degree of esterification of the pectin is less than 50%, more preferably 10%-40%, meaning that the pectin used in this invention is low-ester pectin; the degree of esterification specifically refers to the percentage of esterified galacturonic acid residues in the pectin molecule relative to the total galacturonic acid residues; this invention does not have special requirements regarding the source of the pectin, and pectin from common sources in the art is acceptable, including but not limited to apples, oranges, and lemons.

[0026] In this invention, the pectin short-chain fatty acid ester is preferably one or more of pectin propionate, pectin butyrate, pectin acetate, and pectin valerate.

[0027] In this invention, the preferred method for preparing the pectin short-chain fatty acid ester includes: mixing pectin, an esterifying agent, and a solvent to undergo an esterification reaction to obtain the pectin short-chain fatty acid ester; the esterifying agent is at least one of short-chain fatty acids and short-chain fatty acid anhydrides; the short-chain fatty acid specifically refers to fatty acids with fewer than 6 carbon atoms, including one or more of formic acid, acetic acid, propionic acid, isobutyric acid, butyric acid, isovaleric acid, and valeric acid, preferably including one or more of acetic acid, propionic acid, butyric acid, and valeric acid; the short-chain fatty acid anhydride is the anhydride of the above-mentioned short-chain fatty acids, preferably including one or more of acetic anhydride, propionic anhydride, butyric anhydride, and valeric anhydride; the molar ratio of the short-chain fatty acid anhydride to pectin is preferably (1~5.5):1, more preferably (2~4):1; the molar ratio of the short-chain fatty acid to pectin is preferably (0.5~3.8):1; the temperature of the esterification reaction is preferably 30~65℃, more preferably 40~60℃, and the time of the esterification reaction is preferably 10~18h, more preferably 12~15h.

[0028] In this invention, the solvent preferably includes one or more of water, pyridine, methanol, ethanol, n-butanol, diethyl ether, chloroform, dimethyl sulfoxide, and toluene, more preferably pyridine; the present invention preferably first dissolves pectin in the solvent to obtain a pectin solution, and then adds an esterifying agent dropwise to the pectin solution to carry out an esterification reaction; the mass ratio of pectin to solvent is preferably 1:(1~4.5); the dissolution temperature is preferably 45~65℃, more preferably 50~60℃; the dissolution is preferably carried out under stirring conditions, and the stirring time is preferably 20~35 min.

[0029] After the esterification reaction is completed, the present invention preferably further includes purification of the obtained reaction solution; the purification process includes: washing, extracting, concentrating and drying the obtained reaction solution in sequence to obtain purified pectin short-chain fatty acid esters; the washing reagent is preferably deionized water; the extraction includes sequential organic solvent extraction, saturated sodium chloride solution extraction and saturated sodium bicarbonate solution extraction; the organic solvent used for organic solvent extraction is ethyl acetate or dichloromethane; the concentration method is preferably rotary evaporation concentration; the drying method is preferably vacuum drying.

[0030] After purification, the purified product is preferably sieved to obtain the final product; the mesh size of the sieve used for sieving is preferably 30 mesh. Figure 1 This is a schematic diagram of the preparation process of the pectin short-chain fatty acid ester of the present invention.

[0031] The pectin short-chain fatty acid ester composition provided by the present invention comprises 4-60% metal compound, preferably 10-50%, by weight percentage. In the present invention, the metal compound preferably comprises one or more of a metal salt and a metal oxide; the metal cation in the metal compound preferably comprises Ca. 2+ Mg 2+ Zn 2+ Cu 2+ Al 3+ and Fe 3+ One or more of the following; specifically, the metal compound preferably includes one or more of the following: calcium hydrogen phosphate, calcium carbonate, calcium oxide, calcium citrate, calcium chloride, calcium sulfate, zinc sulfate, zinc gluconate, zinc oxide, zinc carbonate, magnesium sulfate, magnesium chloride, magnesium oxide, magnesium bicarbonate, copper sulfate, ferric citrate, ferric pyrophosphate, and aluminum citrate.

[0032] In this invention, the mass ratio of the metal cation in the metal compound to the pectin unit in the pectin short-chain fatty acid ester is preferably (0.006~0.5):1, more preferably (0.01~0.4):1.

[0033] The present invention also provides a method for preparing the pectin short-chain fatty acid ester composition described above, comprising the following steps: A portion of pectin short-chain fatty acid esters and a metal compound are first mixed to obtain a premix; the mass ratio of the portion of pectin short-chain fatty acid esters to the metal compound is (1~3):1. The premix and the remaining portion of the pectin short-chain fatty acid esters are mixed a second time to obtain the pectin short-chain fatty acid ester composition.

[0034] In this invention, the preferred mixing speed for the first mixing is 6-10 rpm, and the preferred mixing time is 15-40 min; the preferred mixing speed for the second mixing is 6-10 rpm, and the preferred mixing time is 25-45 min; this invention first mixes a portion of the pectin short-chain fatty acid esters and metal compounds, and then adds the remaining portion of the pectin short-chain fatty acid esters for mixing, which helps to improve the uniformity of the mixing.

[0035] In this invention, after the second mixing is completed, it is preferable to further sieve the resulting total mixture, and the undersize material obtained after sieving is the pectin short-chain fatty acid ester composition; the mesh size of the sieve used for sieving is preferably 30 mesh. Figure 2 This is a schematic diagram of the preparation process of the pectin short-chain fatty acid ester composition of the present invention.

[0036] This invention also provides the application of the pectin short-chain fatty acid ester composition described above or the pectin short-chain fatty acid ester composition prepared by the preparation method described above in the preparation of animal feed or in the preparation of pharmaceuticals. Specifically, the pectin short-chain fatty acid ester composition is used as an appetite suppressant; the pharmaceuticals include drugs for treating obesity or drugs for lowering blood sugar. The dosage form of the pharmaceuticals is preferably capsules or tablets.

[0037] In specific embodiments of the present invention, the pectin short-chain fatty acid ester composition can be used in combination with sweeteners, flavorings, etc., and the present invention does not impose specific limitations.

[0038] In a specific embodiment of the present invention, when the pectin short-chain fatty acid ester composition is applied to a solid beverage, the solid beverage preferably includes the following components by weight: 50 parts of pectin short-chain fatty acid ester composition, 20 parts of resistant dextrin, 20 parts of maltodextrin, 10 parts of erythritol, and 0.1 parts of orange flavoring.

[0039] This invention also provides an appetite suppressant product, comprising the pectin short-chain fatty acid ester composition described in the above-described scheme or the pectin short-chain fatty acid ester composition prepared by the preparation method described in the above-described scheme. The dosage form of the appetite suppressant product is powder, liquid preparation, capsule or tablet. This invention does not have special requirements for the specific preparation method of the powder, liquid preparation, capsule or tablet, and any method well known to those skilled in the art can be used for preparation.

[0040] The composition provided by this invention uses low-ester pectin as a carrier of short-chain fatty acids and combines it with metal compounds. Low-ester pectin can bind with polyvalent metal cations in the stomach, increasing the viscosity of chyme, delaying gastric emptying, increasing the feeling of fullness at the meal, and helping to reduce the amount of food consumed at the meal. At the same time, pectin short-chain fatty acid esters can release short-chain fatty acids more persistently and in a targeted manner in the body, prolonging the feeling of fullness time, thereby more effectively reducing appetite and helping with weight management and obesity treatment.

[0041] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0042] The sources of the raw materials and reagents used in the examples are shown in Table 1.

[0043] Table 1. Information on main raw materials in the examples

[0044] Example 1 This embodiment prepares a composition of pectin propionate and calcium salt. The specific preparation steps are as follows: Pectin and pyridine (3 times the weight of pectin) were magnetically stirred in an oil bath at 60°C for 25 min until the pectin was completely dissolved, yielding a pectin solution. Propionic anhydride was added dropwise to the pectin solution while maintaining the temperature at 60°C, with continuous stirring during the addition. The reaction was allowed to proceed for 14 h. After the reaction, the reaction solution was washed with deionized water, and then dichloromethane was added to the reaction solution for extraction. Saturated sodium chloride solution and saturated sodium bicarbonate solution were added sequentially to the resulting dichloromethane phase for washing and extraction. The lower extract was concentrated by rotary evaporation, and the concentrate was then dried in a vacuum drying oven to obtain pectin propionate (PPE) with a degree of substitution of 0.65, a homogeneous texture, and a pale yellow color. The mass percentage of propionic acid units in this pectin propionate was 31%.

[0045] Three parts of the pectin propionate prepared in the above steps were mixed with one part of calcium hydrogen phosphate dihydrate in a three-dimensional mixer at a speed of 6 rpm for 15 min to obtain a premix; the premix was then mixed with 5.2 parts of pectin propionate in a three-dimensional mixer at a speed of 8 rpm for 30 min to obtain a pectin propionate composition.

[0046] Example 2 This embodiment prepares a composition of pectin butyrate and calcium salt. The specific preparation steps are as follows: Pectin and pyridine (4 times the weight of pectin) were magnetically stirred in an oil bath at 55°C for 25 min until the pectin was completely dissolved, yielding a pectin solution. Butyric anhydride was added dropwise to the pectin solution while maintaining the temperature at 55°C, with continuous stirring during the addition. The reaction was allowed to proceed for 16 h. After the reaction, the reaction solution was washed with deionized water, and then dichloromethane was added for extraction. Saturated sodium chloride solution and saturated sodium bicarbonate solution were added sequentially to the resulting dichloromethane phase for washing and extraction. The lower extract was concentrated by rotary evaporation, and the concentrate was dried in a vacuum drying oven to obtain pectin butyrate ester (PBE), a homogeneous, pale yellow substance with a degree of substitution of 0.61. The mass percentage of propionic acid units in this pectin butyrate ester was 26%.

[0047] Three parts of the pectin butyrate prepared in the above steps were mixed with one part of calcium hydrogen phosphate dihydrate in a three-dimensional mixer at a speed of 6 rpm for 15 min to obtain a premix; the premix was then mixed with 4.8 parts of pectin butyrate in a three-dimensional mixer at a speed of 6 rpm for 40 min to obtain a pectin butyrate composition.

[0048] Example 3 Viscosity test of pectin short-chain fatty acid ester compositions under simulated gastric pH conditions. Pectin butyrate and pectin butyrate compositions were derived from Example 2.

[0049] Test sample 1 (P): 3 g of low-ester pectin + 7 g of sucrose.

[0050] Test sample 2 (P-Ca): 3 g low-ester pectin + 0.52 g calcium hydrogen phosphate dihydrate + 6.48 g sucrose.

[0051] Test sample 3 (PBE): 4.05 g pectin butyrate + 5.95 g sucrose.

[0052] Test sample 4 (PBE-Ca): 4.57 g of pectin butyrate composition + 5.43 g of sucrose.

[0053] Note: 1. The sample amount calculated based on pectin content is the same for samples 1-4; 2. The ratio of calcium to pectin is the same in samples 2 and 4.

[0054] Experimental procedure: Add concentrated hydrochloric acid to distilled water to adjust the pH value to 3. Then, pour 10 g of each sample into 100 mL of the above solution, stir with a glass rod, and let stand after stirring evenly. Measure the viscosity of each sample at different time points using a viscometer.

[0055] The viscosity changes of test samples 1-4 are as follows Figure 3 As shown, Figure 3The results showed that: 1) In a solution system with pH=3, all samples showed an increasing viscosity trend over time, and the viscosity stabilized after about 1800 s; 2) The product of pectin and butyric acid combined by esterification (PBE) had a lower overall viscosity than pure pectin; 3) The mixture of pectin and calcium salt (P-Ca) or pectin butyrate and calcium salt (PBE-Ca) showed a significant increase in viscosity in an acidic environment, with a viscosity significantly higher than that of pure pectin or pectin butyrate; 4) The viscosity of the composition of pectin butyrate and calcium salt (PBE-Ca) was lower than that of the mixture of pectin and calcium salt (P-Ca).

[0056] The above findings indicate that a combination of pectin short-chain fatty acid esters and calcium salts in a certain proportion can significantly increase the viscosity of liquids in an acidic environment. However, the viscosity is slightly lower than that of a combination of low-ester pectin and calcium salts. This may be because the combination of low-ester pectin and SCFAs reduces the chemical bonds between the low-ester pectin molecules and calcium ions to some extent, thereby partially reducing the occurrence of the "bridging reaction." However, the viscosity is still significantly higher than that of pectin itself, suggesting that the combination of pectin short-chain fatty acid esters and calcium salts can form a highly viscous chyme with food in the acidic environment of the stomach, indicating that this combination has a good effect on delaying gastric emptying.

[0057] Example 4 In vitro fermentation experiments were conducted to detect the ability of pectin short-chain fatty acid esters to release short-chain fatty acids in the colon. Pectin propionate and pectin butyrate were used from Examples 1 and 2.

[0058] Test protocol: In vitro fermentation of Bifidobacterium: Under aseptic conditions, 9.0 mL of sterile culture medium (Bifidobacterium BS medium, Qingdao Hope Bio-Technology Co., Ltd, catalog number HB0394) was added to a sterile anaerobic tube, followed by 0.1 g of lyophilized Bifidobacterium powder. The tube was shaken to thoroughly mix the bacteria with the medium. Then, at a 10% inoculation rate, the culture was transferred to a sterile anaerobic tube containing 10 mL of medium. The tube was anaerobically cultured at 37°C for 48 h. After two subcultures, the tube was re-inoculated, and fermentation was continued for 16 h to obtain the mother liquor. A culture medium was prepared using pectin, pectin propionate (PPE), and pectin butyrate (PBE) at a concentration of 10 g / 1000 mL as carbon sources. The nutrient composition of the non-carbon source portion was the same as that of the Bifidobacterium BS medium. The medium was sterilized at 120°C for 20 min. Take the mother culture solution and inoculate it at a rate of 10% into a culture medium with pectin, pectin propionate, and pectin butyrate as carbon sources. Mix well and then dispense into anaerobic tubes. Label the tubes sequentially at 0h, 6h, 12h, 18h, 24h, 30h, and 36h. Incubate anaerobically at 37℃. Remove the corresponding anaerobic tubes at the above times and store them at -20℃ for later use.

[0059] Determination of short-chain fatty acids in fermentation broth: First, standard curves for acetic acid, propionic acid, and butyric acid at different concentrations were plotted, and regression equations were established. Fermentation broth samples at each time point were thawed, centrifuged (10000 r / min, 15 min), and the supernatant was collected and filtered through a 0.45 μm filter membrane. The content of short-chain fatty acids (acetic acid, propionic acid, and butyric acid) in the fermentation broth samples was determined by liquid chromatography, with three replicates for each sample.

[0060] Chromatographic analysis conditions: Column: Agilent reverse-flow C18 column (4.6 mm × 150 mm, 5 μm); Mobile phase: 0.02 mol / mL potassium dihydrogen phosphate and methanol, volume ratio 98:2, with the pH adjusted to 2.8 using phosphoric acid; Detection wavelength: 215 nm; Flow rate: 1.0 mL / min; Injection volume: 20 μL.

[0061] Test results: After 36 hours of in vitro fermentation in three culture media, the total SCFA (acetic acid, propionic acid, butyric acid) content was as follows: Figure 4 As shown, the composition of the short-chain fatty acids produced is as follows: Figure 5 As shown. Figure 4The results showed that: 1) the total SCFA produced by in vitro fermentation in all experimental groups increased with the extension of fermentation time; 2) during the fermentation period of 0-6 h, the SCFA increase rate in the fermentation broth of pectin and PPE groups was significantly higher than that in PBE group (P<0.05); 3) after 12 h of fermentation, the total SCFA of pectin short-chain fatty acid groups (PPE, PBE) was higher than that of pectin group; 4) after 18-24 h, the fermentation rate slowed down and the total SCFA content tended to stabilize; 5) after 18-36 h of fermentation, the total SCFA content was: PPE>PBE>pectin, and the difference was significant (P<0.05). Figure 5 The results showed that the propionic acid level produced by fermentation in the PPE group was significantly higher than that in the pectin and PBE groups (P<0.05), and the butyric acid level produced by fermentation in the PBE group was significantly higher than that in the PPE group (P<0.05).

[0062] The above results indicate that short-chain fatty acids (SCFAs) can effectively increase the level of corresponding SCFA esters produced by Bifidobacteria fermentation after binding with pectin via ester bonds. Compared with pectin alone, the total SCFA level produced by pectin SCFA esters with the same pectin content through in vitro fermentation is significantly increased. This suggests that pectin SCFA esters can be fermented by probiotics in the gut to produce more SCFAs, and have great potential in enhancing satiety and controlling weight.

[0063] Example 5 The pectin butyrate composition, pectin propionate composition, propionate (sodium propionate), butyrate (sodium butyrate), and pectin obtained in Examples 1 and 2 were used to feed mice. Forty-eight healthy male mice (Shanghai Southern Model Biotechnology Co., Ltd.), all 5 weeks old and weighing 21±1.9 g, were randomly divided into 6 groups of 8 mice each after one week of acclimatization feeding. Formal intervention began, and all mice in each group were fed the same diet (Research Diets, Inc.; D11112201). The pectin group (P) was administered 3 g / (kg·d) of low-ester pectin by gavage, the pectin propionate composition group (PPE) was administered 3 g / (kg·d) of PPE by gavage, the pectin butyrate composition group (PBE) was administered 3 g / (kg·d) of PBE by gavage, the propionate group (Pr) was administered 3 g / (kg·d) of propionate by gavage, the butyrate group (Bu) was administered 3 g / (kg·d) of butyrate by gavage, and the pectin control group (C) was administered an equal volume of physiological saline by gavage. The mice were fed for 4 weeks. Changes in body weight before and after the intervention were observed. After 4 weeks of feeding, serum GLP-1, PPY, OGTT blood glucose response and insulin response were observed, as well as the content of short-chain fatty acids in feces.

[0064] Indicator collection: Body weight: The weight of mice was measured once before the intervention and once a week after the intervention.

[0065] Fecal SCFA content: At the end of the 4-week experiment, fresh feces from mice in each group were collected under aseptic conditions, stored in sterile EP tubes, and immediately stored at -80℃ for later use. For testing, 0.2 g of frozen feces was placed in an EP tube and thawed. After thawing, 2 mL of methanol solution was added, and the mixture was vortexed for 5 min to prepare a fecal suspension. The pH of the fecal suspension was adjusted to 2-3 with concentrated sulfuric acid, then vortexed for 2 min, and centrifuged at 5000 rpm for 20 min. 1 mL of the supernatant was filtered through a 0.45 μm filter membrane, and the filtrate was collected for SCFA determination.

[0066] GLP-1 and PPY: Four weeks after intervention, orbital venous blood was collected from mice in each group and placed in anticoagulant tubes containing heparin sodium. After standing at 4°C for 2 hours, the blood was centrifuged at 3000 r / min for 10 minutes to separate the serum, and the supernatant serum was collected. The levels of fasting insulin (FIN), glucagon-like peptide-1 (GLP-1), and peptide YY (PYY) in mouse serum were detected according to the instructions of the enzyme-linked immunosorbent assay (ELISA) kit (Shanghai Jianglai Biotechnology Co., Ltd.).

[0067] Test results: Effects on body weight: Changes in mouse body weight before and after 4 weeks of intervention are as follows Figure 6 As shown, Figure 6 middle: A p-value < 0.05 indicates a statistically significant difference compared to pre-intervention levels. Figure 6 The results showed that mice treated with a combination of pectin propionate, sodium propionate, and pectin butyrate experienced a significant decrease in body weight after 4 weeks of intervention, while the changes in the other groups were not significantly different. Among them, the PPE group showed the largest decrease, at 4.7%.

[0068] Fecal SCFA content: Short-chain fatty acid content in mouse feces after 4 weeks of intervention was as follows Figure 7 As shown, Figure 7 middle: # indicates P < 0.05 compared to the control group, and # indicates P < 0.01 compared to the control group. Figure 7The results showed that the fecal SCFA content in mice fed pectin, pectin propionate combination, sodium propionate, pectin butyrate combination, and sodium butyrate for 4 weeks was significantly higher than that in the control group (P<0.01), and the corresponding SCFA content was also significantly higher in the mice fed pectin propionate combination and pectin butyrate combination (P<0.05). The total SCFA content in the feces of mice fed pectin propionate combination and pectin butyrate combination was higher than that in the sodium propionate and sodium butyrate groups (P<0.05), and the propionic acid and butyrate content carried by the feed was also higher in the mice fed pectin propionate combination and sodium butyrate combination. This indicates that direct feeding of sodium propionate and sodium butyrate results in some loss of short-chain fatty acids during digestion, which also verifies the protective effect of pectin on SCFA after binding with SCFA through ester chains, allowing it to enter the intestine more effectively.

[0069] GLP-1 and PPY: Serum PPY levels in mice in each group after 4 weeks of intervention were as follows Figure 8 As shown, Figure 8 middle: This indicates that the value of P < 0.05 compared to the control group. Figure 8 The results showed that the serum PYY level of mice fed with pectin, pectin propionate, sodium propionate, pectin butyrate, and sodium butyrate was significantly higher than that of the control group (P<0.05). Among them, the serum PYY level of mice fed with pectin propionate and pectin butyrate was the highest, which was significantly higher than that of the sodium propionate, sodium butyrate, and pectin groups (P<0.05).

[0070] Serum GLP-1 levels in mice in each group after 4 weeks of intervention are as follows: Figure 9 As shown, Figure 9 middle: This indicates that the value of P < 0.05 compared to the control group. Figure 9 The results showed that the GLP-1 levels of the pectin propionate composition, sodium propionate, and pectin butyrate composition were significantly higher than those of the control group (P<0.05). There was no significant difference between the pectin propionate and sodium propionate composition groups and the control group. The GLP-1 levels of mice in the pectin propionate and pectin butyrate composition groups were slightly higher than those in the sodium propionate group, but there was no statistical difference.

[0071] The above results validate the positive effects of pectin short-chain fatty acid ester compositions on satiety and weight control. They also confirm that linking pectin and SCFAs through esterification reduces SCFA loss before it enters the intestines, ensuring more SCFAs reach the gut and exert their health benefits. Furthermore, the short-chain fatty acid ester composition is more effective than simply supplementing with pectin or SCFA salts in enhancing satiety and controlling weight. Pectin short-chain fatty acid ester compositions have significant potential in regulating gut microbiota, enhancing satiety, controlling weight, and even reducing glycemic response.

[0072] Example 6 The pectin propionate composition obtained in Example 1 was used as a meal-prepared beverage in a preliminary human trial to observe its effects on satiety and postprandial blood glucose.

[0073] Research plan: A double-blind, randomized, controlled, crossover trial was conducted in 10 healthy individuals. The participants consumed a meal-based beverage in three groups: the blank control group (BC) received a powder (solid beverage) containing 4.2 g / serving of sweetener (erythritol) and orange flavoring; the standard control group (P) received a powder containing 6 g of pectin, also flavored with erythritol and orange flavoring, at 12.5 g / serving; and the experimental group (PPE-Ca) received a powder containing 6 g of pectin propionate, also flavored with erythritol and orange flavoring, at 15 g / serving. Erythritol and orange flavoring were used to ensure similar taste across the three groups. All three powders (solid beverages) were mixed with 150 mL of warm water before being distributed to the participants. All participants fasted for 12–14 hours and consumed a standard meal plus the solid beverage between 8:30 and 9:00 AM on the experimental day. Each serving of the solid powder was mixed with 150 mL of warm water and consumed with the meal. The standard meal consisted of commercially available red bean buns, providing 312 kcal of energy, 6.2 g of protein, 58 g of carbohydrates, and 6.1 g of fat. All beverages and food were consumed within 10-15 minutes. Researchers recorded blood glucose levels before and 2 hours after the meal, as well as satiety levels before and 4 hours after the meal. A 3-day washout period was established between test meals. All participants received different test meals on the same experimental day according to a randomized sequence automatically generated from a random number table operated by statisticians; each participant underwent all test meal trials.

[0074] Data collection: 1) Subjective Appetite Evaluation: In the RPG meal-based formulation study, the Visual Analogue Scale (VAS) was used to evaluate subjects' subjective appetite and satiety. Specific indicators included satiety, hunger, fullness, and prospective food consumption. Each indicator was rated from 0 to 100, representing two extremes. For example, in the hunger evaluation, 0 points indicated "I am not hungry at all," and 100 points indicated "I have never been more hungry." Subjects began completing the first questionnaire (t0) within 5 minutes before starting to eat, and then every 15 minutes for the next hour, and every 30 minutes after that, for a total of 4 hours. The questionnaire completion times were: t0, t15, t30, t45, t60, t90, t120, t150, t180, t210, and t240. Overall Appetite Suppression Score (OASS) = [Satisfaction Score + Satiety Score + (100 - Hunger Score) + (100 - Expected Food Intake Score)] / 4.

[0075] 2) Blood glucose index: All subjects wore a silicon-based dynamic continuous glucose monitoring system (CGM) (National Medical Device Registration Certificate No. 20213070871) for 2 days in advance to monitor blood glucose data at 10 and 5 minutes before meals and at 15, 30, 45, 60, 90 and 120 minutes after the start of eating on the test day. The average of the two blood glucose data before meals was used as the pre-meal blood glucose data.

[0076] 3) Adverse events: During all trial days, subjects were asked to record the time of ingestion of the test food, adverse events (bloating, belching, flatulence, nausea, diarrhea, etc.), illnesses, and medication use.

[0077] Test results: The VAS scores for hunger, satiety, expected food intake, fullness, and appetite suppression over time are as follows: Figure 10 As shown. Figure 10The results showed that: 1) The hunger and expected food intake scores of the PPE-Ca group were significantly lower than those of the other two groups 30 minutes after eating (P<0.05). Except for the expected food intake at 210 and 240 minutes, the scores of the P group were significantly lower than those of the BC group (P<0.05), while the scores at other time points were slightly lower overall, but there was no statistical difference (P>0.05); 2) The satiety of the PPE-Ca group was significantly higher than that of the other two groups from 45 to 180 minutes. The P group was significantly higher than the BC group at 210 and 240 minutes (P<0.05). The satiety of the PPE-Ca group was significantly higher than that of the BC group at 30, 210, and 240 minutes (P<0.05), and slightly higher than that of the BC group at other times, but there was no statistical difference; 3) The total appetite suppression score of the PPE-Ca group was significantly higher than that of the other two groups after 45 minutes (P<0.05).

[0078] The blood glucose increase curves after eating for each group are as follows: Figure 11 As shown, Figure 11 middle: # indicates a significant difference between the PPE-Ca group and the BC group (P<0.05); # indicates a significant difference between the P group and the BC group (P<0.05); the increase in the area under the blood glucose response curve after eating for each group is shown in the figure. Figure 12 As shown, Figure 12 middle: # indicates a significant difference compared to group BC (P<0.05); # indicates a significant difference compared to group BC (P<0.05). Figures 11-12 The results showed that: 1) The increase in postprandial blood glucose in the PPE-Ca group at 30, 45, and 60 min was significantly lower than that in the blank control group (P<0.05), and the increase in blood glucose in the P group at 45 min was significantly lower than that in the blank control group (P<0.05). At 15, 30, and 120 min postprandial, the increase in blood glucose in the PPE-Ca group was smaller than that in the P group, but there was no statistical difference; 2) The increase in the area under the postprandial blood glucose response curve (IAUC) in the P group and the PPE-Ca group was significantly smaller than that in the blank control group (P<0.05), and the IAUC in the PPE-Ca group was significantly smaller than that in the P group (P<0.05).

[0079] In addition, no adverse gastrointestinal symptoms such as nausea, vomiting, abdominal distension, diarrhea, or abdominal pain were observed during the trial.

[0080] The above results indicate that the combination of pectin short-chain fatty acid esters and calcium salts has a significant effect on blood sugar control and improving satiety, and its effect is significantly better than that of pectin alone, suggesting the great potential of this combination in weight loss and blood sugar management. At the same time, this experiment has, to some extent, verified the safety of this combination.

[0081] Example 7 The pectin propionate composition from Example 1, combined with other raw materials, is formulated into a solid beverage. It can be consumed after dilution with water, either before or with meals, to maximize its health benefits. The specific formula and process are as follows: Weigh out 50 parts of pectin propionate composition, 20 parts of resistant dextrin, 20 parts of maltodextrin, 10 parts of erythritol, and 0.1 parts of orange flavor. Mix all raw materials step by step to ensure uniform mixing, as follows: Premix orange flavor and erythritol are premixed to obtain premix 1. Premix 1 is then mixed with maltodextrin and 1 / 2 of the resistant dextrin to obtain premix 2. Premix 2 is then mixed with the pectin propionate composition and the remaining 1 / 2 of the resistant dextrin to obtain the solid powder product.

[0082] The results of the above embodiments demonstrate that the pectin short-chain fatty acid ester composition provided by the present invention can improve the appetite-suppressing effect and overcome some limitations of existing similar technologies. The present invention uses low-ester pectin as a carrier to bind with polyvalent metal cations in the stomach, increasing chyme viscosity, delaying gastric emptying, and enhancing satiety during meals, thus helping to reduce food intake. Simultaneously, the pectin short-chain fatty acid esters can release SCFAs more persistently and directionally in vivo, prolonging the duration of satiety and thus more effectively reducing appetite, aiding in weight management and obesity treatment. Furthermore, the preparation process of the pectin short-chain fatty acid esters of the present invention is simple to operate and produces high-purity products, which helps improve the feasibility of this technology in practical applications.

[0083] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A pectin short-chain fatty acid ester composition comprising the following components in weight percentages: 40-96% pectin short-chain fatty acid ester and 4-60% metal compound; wherein the pectin short-chain fatty acid ester is one or more selected from pectin propionate, pectin butyrate, pectin acetate, and pectin valerate; and wherein the metal compound is calcium hydrogen phosphate.

2. The pectin short-chain fatty acid ester composition according to claim 1, characterized in that, The short-chain fatty acid ester of the pectin contains 10% to 60% by mass of short-chain fatty acid units.

3. The pectin short-chain fatty acid ester composition according to claim 1, characterized in that, The degree of substitution of short-chain fatty acids in the pectin short-chain fatty acid ester is 0.2 to 1; the degree of esterification of the pectin is less than 50%.

4. The pectin short-chain fatty acid ester composition according to claim 1, characterized in that, The method for preparing the pectin short-chain fatty acid ester includes: Pectin, an esterifying agent, and a solvent are mixed and subjected to an esterification reaction to obtain the pectin short-chain fatty acid ester; the esterifying agent is at least one of short-chain fatty acids and short-chain fatty acid anhydrides.

5. The pectin short-chain fatty acid ester composition according to claim 4, characterized in that, The esterifying agent is a short-chain fatty acid anhydride, and the molar ratio of the short-chain fatty acid anhydride to pectin is (1~5.5):1; the esterification reaction temperature is 30~65℃, and the time is 10~18h.

6. The pectin short-chain fatty acid ester composition according to claim 4, characterized in that, After the esterification reaction is completed, the resulting reaction solution is purified to obtain pectin short-chain fatty acid esters. The purification process includes washing, extracting, concentrating and drying the resulting reaction solution in sequence to obtain purified pectin short-chain fatty acid esters. The extraction includes sequential organic solvent extraction, saturated sodium chloride solution extraction and saturated sodium bicarbonate solution extraction. The organic solvent used for the organic solvent extraction is ethyl acetate or dichloromethane.

7. A method for preparing the pectin short-chain fatty acid ester composition according to any one of claims 1 to 6, characterized in that, Includes the following steps: A portion of pectin short-chain fatty acid esters and a metal compound are first mixed to obtain a premix; the mass ratio of the portion of pectin short-chain fatty acid esters to the metal compound is (1~3):

1. The premix and the remaining portion of the pectin short-chain fatty acid esters are mixed a second time to obtain the pectin short-chain fatty acid ester composition.

8. The use of the pectin short-chain fatty acid ester composition according to any one of claims 1 to 6 or the pectin short-chain fatty acid ester composition prepared by the preparation method of claim 7 in the preparation of animal feed.

9. An appetite suppressant product, characterized in that, The product includes the pectin short-chain fatty acid ester composition according to any one of claims 1 to 6 or the pectin short-chain fatty acid ester composition prepared by the preparation method of claim 7; the dosage form of the appetite suppressant product is powder, liquid preparation, capsule or tablet.

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