Starch film-forming composition and preparation method of soft capsule of starch film-forming composition

Abstract

The invention provides a starch film-forming composition and a preparation method of a soft capsule of the starch film-forming composition. The starch film-forming composition comprises 25-60 wt% of acid-treated starch, 20-40 wt% of a plasticizer and 15-40 wt% of water, the gelatinization viscosity of the acid-treated starch is 5-196 mPa.s, optionally, the gelatinization viscosity is 10% w / w starch liquid prepared from the acid-treated starch and water, and the phosphate ester content of the acid-treated starch is 0.01-0.06% (on the basis of phosphorus P). The soft capsule prepared from the starch film-forming composition is short in drying time and uniform in moisture, so that the production cost of the soft capsule is reduced.

Description

Technical Field

[0001] This invention relates to the field of soft capsules, and more specifically to starch film-forming compositions and methods for preparing soft capsules thereof. Background Technology

[0002] Currently, the vast majority of plant-based soft capsules on the market use edible gums (carrageenan, gellan gum, pectin, etc.) and modified starch as their main raw materials. However, the colloids formed by blends of edible gums and starch, or starch blends, have extremely poor flowability, unlike gelatin which has excellent flowability. Therefore, mechanical force or high pressure is required to propel the colloid, increasing production costs and posing significant safety risks.

[0003] CN118141090A discloses a highly stable soft capsule shell and its preparation method. The highly stable soft capsule shell comprises 10-40 parts gelatin, 1-10 parts tamarind gum, 5-30 parts starch, 5-25 parts plasticizer, 5-10 parts water-retaining agent, 0.1-2 parts food additives, and 20-40 parts water. The water-retaining agent is selected from one or more of xylitol, mannitol, and trehalose. This patent application solves the problem of rapid drying by adding a water-retaining agent.

[0004] CN114306272A discloses a plant-based soft capsule, its preparation method, and its uses. The plant-based soft capsule comprises 3-20 parts carrageenan, 10-50 parts starch, 10-35 parts plasticizer, and 30-70 parts water. This patent application utilizes drum heating to achieve rapid water loss.

[0005] There is still a need in the art for more starch film-forming compositions. Summary of the Invention

[0006] This invention, through the study of the properties of different modified starches, found that acid-treated starches containing 0.01-0.06% (calculated as phosphorus P) phosphate ester content and a gelatinization viscosity of 5-196 mPa·s have strong gelling properties and high gel strength. When mixed with plasticizer and water in a certain proportion, they exhibit film-forming properties.

[0007] This invention provides a starch film-forming composition comprising: acid-treated starch, a plasticizer, and water. A novel acid-treated starch was obtained by controlling the gelatinization viscosity of the acid-treated starch to be 5-196 mPa·s and the phosphate ester group content to be 0.010-0.060% (calculated as phosphorus P). The starch film-forming composition formed using this novel acid-treated starch has the following characteristics: rapid water loss efficiency, suitable for making soft capsules, and the resulting soft capsules have a short drying time and uniform moisture content. In one embodiment, the gelatinization viscosity is the viscosity value measured at the starch gelatinization temperature using a rotational rheometer after preparing a 10% w / w starch solution from the acid-treated starch and water. In one embodiment, the phosphate ester group content is determined according to GB 5009.87-2016, "National Food Safety Standard - Determination of Phosphorus in Food".

[0008] In one aspect, the present invention provides a starch film-forming composition comprising 25-60 wt% acid-treated starch, 20-40 wt% plasticizer and 15-40 wt% water, wherein the acid-treated starch has a gelatinized viscosity of 5-196 mPa·s and a phosphate ester group content of 0.010-0.060% (calculated as phosphorus P).

[0009] In one embodiment, the acid-treated starch is one or more of acid-treated corn starch, acid-treated pea starch, acid-treated potato starch, and acid-treated wheat starch.

[0010] In one embodiment, the acid-treated starch is amylose and / or amylopectin.

[0011] In one embodiment, the plasticizer is one or more of glycerol, propylene glycol, polyethylene glycol, sorbitol, erythritol, and maltitol.

[0012] In one embodiment, the plasticizer content is 22wt%-38wt%.

[0013] In one implementation, the water content is 18wt%-37wt%.

[0014] In one embodiment, the starch film-forming composition further comprises one or more of a second starch, different from the acid-treated starch, a pigment, and a flavoring.

[0015] In one embodiment, the second starch is one or more of hydroxypropyl starch, cross-linked starch, acetate starch, oxidized starch, and natural starch.

[0016] In one embodiment, the content of the second starch is 2-8 wt%.

[0017] In one embodiment, the content of pigments and / or flavors is an acceptable level for soft capsules.

[0018] In one embodiment, the starch film-forming composition comprises an edible gum. Preferably, the edible gum is one or more selected from gelatin, carrageenan, agar, sodium alginate, pectin, xanthan gum, and locust bean gum. Preferably, the edible gum content is 0.1-20 wt%.

[0019] In one embodiment, the starch film-forming composition does not contain edible gum. In another embodiment, the starch film-forming composition does not contain gelatin.

[0020] In one embodiment, the starch film-forming composition does not further contain a water-retaining agent.

[0021] In one embodiment, the starch film-forming composition does not contain one or more of trehalose, mannitol, and xylitol.

[0022] In one embodiment, the plasticizer is glycerol and the starch film-forming composition does not further contain a water-retaining agent.

[0023] In another aspect, soft capsule shells are provided that comprise or are prepared from the starch film-forming composition described herein. In one embodiment, the water content of the soft capsule shell is 9-15 wt%.

[0024] In another aspect, a method for preparing soft capsules is provided, comprising the following steps:

[0025] (1) A glue solution is prepared using raw materials comprising the starch film-forming composition described herein, and the glue solution is formed into a rubber sheet.

[0026] (2) The rubber sheet is prepared into a molded soft capsule, and

[0027] (3) The shaped soft capsules are dried to a moisture content of less than 15% to obtain soft capsules; wherein the drying time of the shaped soft capsules is less than 10 hours, for example 4-10 hours, 5-9 hours, 5-8 hours, 5-7 hours or 5-6 hours.

[0028] In one embodiment, the drying conditions are ambient conditions or drying conditions with a temperature of 20-25°C and a humidity of 10-30%. In one embodiment, the drying process is carried out under static conditions or without turning. In one embodiment, the drying method is tray drying.

[0029] In one implementation, the method includes

[0030] A) Mix water and plasticizer to obtain a premix.

[0031] B) The premix is ​​mixed with acid-treated starch to obtain a gel, for example, by heating and mixing at 90-95°C for 1-1.5 hours;

[0032] C) Prepare molded soft capsules from the gel and dry the molded soft capsules to a moisture content of less than 15%.

[0033] In one embodiment, step B) further includes one or more of a second starch, edible gum, pigment, and flavoring. In another embodiment, the method further includes conveying the glue solution to the glue box of a soft capsule filling machine, extending and cooling it on a rotating drum to form a rubber sheet, and filling the soft capsule with contents during mold cutting and sewing.

[0034] In one embodiment, the adhesive is transported from a storage tank to a cartridge via a hose under gravity or by compressed air at 0.05-0.1 MPa.

[0035] In one embodiment, the formed soft capsules are dried to a moisture content of 9-15%; in another embodiment, the contents are a powder or liquid active ingredient. The contents may be an oil, preferably algal oil.

[0036] In another aspect, soft capsules are provided, comprising a soft capsule shell as described herein or prepared by the methods described herein. In one embodiment, the soft capsule comprises contents. Preferably, the contents are a powder or liquid active ingredient. In one embodiment, the contents are an oil, preferably algal oil.

[0037] In another aspect, the use of the soft capsule shells or soft capsules described herein in food or cosmetics or in the preparation of medicines is provided.

[0038] The present invention has the following technical advantages and beneficial effects:

[0039] (1) The solid matrix in the formulation of this invention is mainly starch, which can be free of any animal-derived protein, is safe and non-toxic, and can meet the consumption needs of people with different religious beliefs and special dietary groups at the same time.

[0040] (2) The starch used in the formula of this invention is widely available, inexpensive, biodegradable, and can significantly reduce production costs. Moreover, the production process generates less waste, which is environmentally friendly.

[0041] (3) The starch film-forming composition of the present invention has excellent processing technology for preparing soft capsules. It can obtain molded soft capsules with a moisture content of less than 15% in a short drying time under conventional drying chamber conditions, and the moisture content is uniform. The preparation method of the present invention can reduce the requirements for drying conditions, shorten the drying time, and reduce the manual intervention in the drying process, thereby reducing production costs. Attached Figure Description

[0042] Figure 1 A schematic diagram of the sampling points for each drying tray is shown. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. 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.

[0044] As used herein, "starch film-forming composition" refers to a mixture with starch as the main component and various auxiliary components added to give it good film-forming properties.

[0045] As used in this article, "acid-treated starch" refers to a type of modified starch obtained by treating natural starch with inorganic acids at temperatures below the gelatinization temperature, thereby altering its properties; it is also known as acid-modified starch. During acid treatment, the glycosidic bonds in starch molecules are hydrolyzed under the action of acid, leading to the breakage of the chain-like portions of the starch molecules and a reduction in molecular weight. The degree of acid hydrolysis differs between amylose and amylopectin. Amylose is composed of α-1,4 glycosidic bonds, while amylopectin is composed of α-1,4 glycosidic bonds and a small number of α-1,6 glycosidic bonds. During acid treatment, amylopectin in the amorphous regions is more easily penetrated and hydrolyzed by acid, while amylose in the crystalline regions is relatively more difficult to hydrolyze. Therefore, the acid hydrolysis process of starch is divided into two steps: first, rapid hydrolysis of amylopectin in the amorphous regions, followed by hydrolysis of amylose in the crystalline regions, although the latter is slower. Sources of acid-treated starch can include corn, peas, potatoes, and wheat. Acid-treated starch can be amylose and / or amylopectin. The gelatinization viscosity range of acid-treated starch varies depending on its raw materials (such as corn, potato, wheat starch, etc.), the degree of acid treatment (degree of hydrolysis), and testing conditions (concentration, temperature, instrument). Commercially available acid-treated starches typically have gelatinization viscosities ranging from 500 to 3000 mPa·s. As used herein, gelatinization viscosity refers to the viscous characteristics exhibited by starch during gelatinization. Starch granules absorb water and swell under heating and the action of water, disrupting their crystalline structure and forming a homogeneous paste system; this process is called gelatinization. Gelatinization viscosity refers to the magnitude of the internal friction force exhibited by this paste system when flowing or subjected to shear force, and is usually measured using a viscometer, with units of centipoise (cP) or Brookfield viscosity (mPa·s). In this paper, a 10% w / w solution of acid-treated starch was prepared with water, and the viscosity value at the starch gelatinization temperature was measured using a rotational rheometer; this is the gelatinization viscosity of the acid-treated starch. In this invention, the gelatinization viscosity of the acid-treated starch can be 5-195 mPa·s.

[0046] As used herein, plasticizers are substances that make food materials easier to process and shape, and impart softness, elasticity, or extensibility by reducing the interactions between macromolecular chains. Plasticizers may contain one or any combination of glycerol, propylene glycol, polyethylene glycol, sorbitol, erythritol, and maltitol.

[0047] As used herein, a water-retaining agent is an additive that can adsorb and lock in moisture through physical or chemical action, preventing moisture loss and maintaining the texture of a product. The starch film-forming composition described herein contains a plasticizer but does not further contain a water-retaining agent. Specifically, the water-retaining agent is one or any combination of trehalose, mannitol, and xylitol.

[0048] As used herein, ambient condition refers to the conditions of the medium surrounding the soft capsule (e.g., pressure, temperature, etc.). The soft capsules described herein can be directly placed in a drying chamber for drying during the preparation process without the need for heating or dehumidification.

[0049] When referring to a numerical range in this article, we include any integer or fraction within that range, as well as any range between them. For example, when we say "20-40wt%", we include 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, 26 wt%, 27 wt%, 28 wt%, 29 wt%, 30 wt%, 31 wt%, 32 wt%, 33 wt%, 34 wt%, 35 wt%, 36 wt%, 37 wt%, 38 wt%, 39 wt%, 40 wt%, and any fractions between them, as well as any combination of both.

[0050] It should be understood that the last significant digit of the values ​​listed here is obtained by rounding; specifically, for example, when the weight percentage is 17.4%, the decimal "4" in the percentage display is rounded to 17%, and for example, when the weight percentage is 17.6%, the decimal "6" in the percentage display is rounded to 18%. Unless otherwise specified, the other parameter values ​​listed in the Specific Embodiments section of this application can be understood in the same way.

[0051] Acid-treated starch

[0052] The gelatinized viscosity of acid-treated starch is typically 500-3000 mPa·s. In this document, acid-treated starch can be further acid-treated to reduce the gelatinized viscosity to 5-196 mPa·s. Methods or means for reducing gelatinized viscosity are known to those skilled in the art, or acid-treated starch with reduced gelatinized viscosity can be commercially available. It should be understood that although the acid-treated starch used in this application with a gelatinized viscosity of 5-196 mPa·s is still referred to as acid-treated starch, it differs from currently available acid-treated starches, at least in physical aspects such as gelatinized viscosity.

[0053] Acid-treated starches typically do not contain significant phosphate groups (unless the raw material itself contains phosphorus or there are process residues). During the production of acid-treated starches, phosphate groups are usually not actively introduced because the primary purpose of acid treatment (such as hydrolysis with HCl or H₂SO₄) is to reduce the molecular weight of the starch (reduce viscosity), not esterification. However, some starches may naturally contain phosphate groups, or trace amounts of phosphorus may be detected after acid treatment due to process residues (such as phosphate buffer).

[0054] The upper limit for phosphate ester content in acid-treated starch is 0.1% (calculated as phosphorus phosphorus). Any content exceeding this limit must be considered phosphate ester starch. Functional properties change, with increased viscosity (phosphate esters enhance swelling capacity). The negative charge of the phosphate ester groups in acid-treated starch enhances the repulsive forces between starch molecules, disrupts the hydrogen bond network, weakens the crystalline structure, and allows water molecules to penetrate more easily into the granules, accelerating starch gelatinization. During drying, water molecules evaporate rapidly, and the phosphate ester groups inhibit starch retrogradation, preventing moisture absorption and reabsorption due to molecular recrystallization after drying, resulting in higher moisture stability.

[0055] This invention has discovered that by using acid-treated starch with a phosphate ester content of 0.010-0.060% (calculated as phosphorus P) and controlling its gelatinization viscosity to 5-196 mPa·s, the resulting colloid or liquid exhibits excellent flowability, flowing very smoothly under gravity. The molding film formed from the starch film-forming composition reaches the target moisture value within 10 hours of drying, with uniform moisture content. The resulting soft capsules have more uniform moisture content, and the preparation process eliminates the need for manual turning, significantly reducing production costs.

[0056] Starch film-forming composition

[0057] Modified starch possesses stable physicochemical properties and exhibits good gelling ability, film-forming properties, and mechanical properties. Soft capsules can be fabricated by combining modified starch in specific proportions to form film compositions. However, the drying time for soft capsules is lengthy, requiring over 24 hours to control the moisture content below 15%. Furthermore, manual turning of the soft capsules during drying is necessary to ensure uniform moisture content and prevent issues such as capsule sagging and stickiness caused by uneven moisture distribution. This reduces the yield of substandard capsules but increases labor costs.

[0058] The film-forming compositions currently available (whether plant gum systems or starch gum systems) produce liquids that are less fluid than gelatin systems. They require mechanical pressure or high-compressed air (usually 0.15-0.2 mPa) to force the liquid to flow and form a film, as well as to make soft capsule shells. This increases the difficulty of soft capsule manufacturing.

[0059] In addition, to shorten the drying time of soft capsules and ensure uniform moisture content, a high-temperature (e.g., elevated or heated, such as above 35°C) and low-humidity drying environment is required, combined with dynamic drying using a rotating drum. Although the drying time has been shortened from the original 24-36 hours to between 15-20 hours, some negative impacts have also been introduced. For example, the high-temperature drying environment accelerates the aging of the capsule skin and the oxidative degradation of the soft capsule contents, and the prolonged dynamic rotation of the drum increases the risk of friction scratches on the surface of the soft capsule skin.

[0060] The novel acid-treated starch described in this article, when mixed with plasticizer and water in a specific ratio, can be dissolved to form a highly fluid colloid, creating a starch film-forming composition. Soft capsules prepared from this starch film-forming composition exhibit high water loss efficiency, with a moisture content below 15% within 10 hours. The resulting soft capsules have more uniform moisture content, eliminating the need for manual turning and significantly reducing production costs. Starch undergoes more chain breakage during acid hydrolysis, generating more small molecular fragments. Because its branched structure is easily disrupted by acid hydrolysis, the gelatinized viscosity is lower, and the gel structure after acid treatment is looser, resulting in faster water loss.

[0061] The starch film-forming composition described herein comprises the novel acid-treated starch, plasticizer, and water. The content of acid-treated starch, by weight of the starch film-forming composition, can be 25-60 wt%, for example, 25 wt%, 26 wt%, 27 wt%, 28 wt%, 29 wt%, 30 wt%, 31 wt%, 32 wt%, 33 wt%, 34 wt%, 35 wt%, 36 wt%, 37 wt%, 38 wt%, 39 wt%, 40 wt%, 41 wt%, 42 wt%, 43 wt%, 44 wt%, 45 wt%, 46 wt%, 47 wt%, 48 wt%, 49 wt%, 50 wt%, 51 wt%, 52 wt%, 53 wt%, 54 wt%, 55 wt%, 56 wt%, 57 wt%, 58 wt%, 59 wt%, 60 wt%, or any range therebetween. The plasticizer content can be 20-40 wt%, for example 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, 26 wt%, 27 wt%, 28 wt%, 29 wt%, 30 wt%, 31 wt%, 32 wt%, 33 wt%, 34 wt%, 35 wt%, 36 wt%, 37 wt%, 38 wt%, 39 wt%, 40 wt%, or any range therebetween. The water content can be 15-40 wt%, for example 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, 26 wt%, 27 wt%, 28 wt%, 29 wt%, 30 wt%, 31 wt%, 32 wt%, 33 wt%, 34 wt%, 35 wt%, 36 wt%, 37 wt%, 38 wt%, 39 wt%, 40 wt%, or any range therebetween. In this paper, the gelatinized viscosity of acid-treated starch can be 5-196 mPa·s, for example, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 196 mPa·s and any integer or fractional value between these values, or any range of both. Gelatinized viscosity can be determined using methods conventional in the art, such as by preparing a 10% w / w starch solution from acid-treated starch and water, and measuring the viscosity at the starch gelatinization temperature using a rotational rheometer.

[0062] The starch film-forming composition described herein may also contain one or more of a second starch, pigment, and flavor, different from the novel acid-treated starch described herein. The second starch may be one or more of hydroxypropyl starch, cross-linked starch, acetate starch, oxidized starch, and natural starch. The content of the second starch may be 2-8 wt%, for example, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, or any range therebetween. The content of pigment and / or flavor is acceptable for soft capsules and is amounts conventionally used in the field of soft capsule preparation.

[0063] The starch film-forming compositions described herein may or may not contain edible gums. Edible gums may be one or more of gelatin, carrageenan, agar, sodium alginate, pectin, xanthan gum, and locust bean gum. Preferably, the starch film-forming compositions do not contain animal-derived edible gums, such as gelatin. When the starch film-forming compositions contain edible gums, the content of the edible gums is 0.1-20 wt%, for example, 0.5 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, or any range thereof.

[0064] The starch film-forming composition may not further contain a water-retaining agent. Preferably, the starch film-forming composition does not contain one or more of trehalose, mannitol, and xylitol. Preferably, the plasticizer is glycerol and the starch film-forming composition does not further contain a water-retaining agent.

[0065] Preparation method of soft capsules

[0066] This invention provides a method for preparing starch soft capsules, comprising: A) mixing water and a plasticizer to obtain a premix; B) heating and mixing the premix with acid-treated starch at 90-95°C for 1-1.5 hours to obtain the starch film-forming composition. Step B) may further include adding one or any combination of hydroxypropyl starch, cross-linked starch, acetate starch, oxidized starch, and natural starch. Step B) may further include adding edible gums, including one or any combination of gelatin, carrageenan, agar, sodium alginate, pectin, xanthan gum, and locust bean gum. The above method may include conveying the starch film-forming composition to the left and right glue boxes of a soft capsule filling machine, extending and cooling on a rotating drum (e.g., 15-20°C) to form a rubber sheet, and filling the contents during mold cutting and sewing to form a soft capsule. The formed soft capsules can be dried at 20-25°C and 10-30% humidity for 4-10 hours to a moisture content of 9-15% to obtain the soft capsules of this invention. When the soft capsules made using this invention are produced, the drying process is faster and the moisture content is more even.

[0067] The method for preparing soft capsules described herein includes the following steps: (1) preparing a gel solution using the starch film-forming composition described herein as a raw material, and forming the gel solution into a rubber sheet; (2) preparing the rubber sheet into a molded soft capsule; and (3) drying the molded soft capsule to a moisture content of less than 15% (e.g., 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%) to obtain a soft capsule; wherein the drying time of the molded soft capsule is less than 10 hours (e.g., 1, 2, 3, 4, 5, 6, 7, 8 or 9 hours), such as 4-10 hours, 5-9 hours, 5-8 hours, 5-7 hours or 5-6 hours. The drying conditions of this method can be ambient conditions, or drying conditions with a temperature of 15-35°C (e.g., 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35°C) and humidity of 10-30% (e.g., 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%). The drying step of this method does not require further heating. Preferably, the drying process is carried out under static conditions or without turning. Preferably, the process of forming the adhesive into a rubber sheet is carried out under normal pressure. More specifically, the method includes A) mixing water and a plasticizer to obtain a premix; B) mixing the premix with acid-treated starch to obtain a glue solution, for example, heating and mixing at 90-95°C for 1-1.5 hours; optionally, one or more of a second starch and edible gum are added in step B); C) preparing molded soft capsules from the glue solution and drying the molded soft capsules to a moisture content of less than 15%. Preferably, the method further includes conveying the glue solution to a glue box of a soft capsule filling machine, extending and cooling on a drum to form a rubber sheet, and filling the soft capsules with contents during mold cutting and sewing. Preferably, the molded soft capsules are dried to a moisture content of 9-15%. Preferably, the contents are a powdered or liquid active ingredient, such as oil, preferably algal oil. Preferably, the glue solution is conveyed from a storage tank to the glue box through a glue tube under gravity or by compressed air at 0.05-0.1 MPa.

[0068] Example

[0069] To better illustrate and demonstrate the effects of the present invention, the following indicators were used to evaluate the sample examples and control examples. All materials and instruments used in the examples were commercially available. All measurement methods used were conventional methods in the art.

[0070] method

[0071] 1. Drying time determination

[0072] Using the tray drying method, 30 trays in total were dried in a drying chamber under drying conditions (temperature 20-25℃, humidity 10-30%). The moisture content of the soft capsules at different drying time points was measured, with a target moisture value of 9-15%, to evaluate the drying time.

[0073] 2. Evaluation of coefficient of variation

[0074] From the bottom to the top, the 1st to the 30th trays of a cart were used to measure the moisture content of soft capsules at different locations and points. The coefficient of variation was used to evaluate the uniformity and stability of the capsules.

[0075] Moisture content was measured in soft capsules taken from the first tray at four corners and one midpoint.

[0076] Take the 15th plate and test the moisture content of the soft capsules at the four corners and one midpoint.

[0077] Take the 30th plate and test the moisture content of the soft capsules at the four corners and one midpoint.

[0078] Sampling points for each drying tray, such as Figure 1 As shown.

[0079] Coefficient of variation (CV = standard deviation / mean × 100%)

[0080]

[0081] 3. Halogen rapid moisture analyzer was used to determine the moisture content of the soft capsule shell.

[0082] Detection principle: The core principle of the halogen rapid moisture analyzer is thermogravimetric analysis, which involves heating the sample to evaporate the moisture and calculating the moisture content based on the mass difference before and after heating.

[0083] Moisture content (%) = (Initial weight - Dried weight) / Initial weight x 100%

[0084] The specific operating steps are as follows:

[0085] Preheating: Turn on the power to the halogen rapid moisture analyzer and preheat to the set temperature.

[0086] Sampling: Use the sample tray or sample spoon provided with the instrument to take an appropriate amount of sample (usually a few grams).

[0087] Weighing: Place the sample into the instrument, and the instrument will automatically record the initial weight.

[0088] Heating and drying: The instrument heats the sample according to a preset heating program to evaporate the moisture.

[0089] Real-time monitoring: The instrument's built-in balance monitors changes in sample mass in real time and transmits the data to the processor.

[0090] Calculate moisture content: When the sample reaches constant weight or reaches the preset drying time, the instrument automatically stops heating and calculates the moisture content of the sample based on the mass loss.

[0091] The results show that the moisture content is displayed directly on the instrument screen, and the data can be printed or saved.

[0092] 4. Evaluation of the flowability of the adhesive solution under gravity conditions

[0093] Take 200g of glue solution into a 500ml beaker, tilt the beaker at a 45-degree angle downwards. The glue solution should flow out normally and smoothly within 1 minute. If it does not flow out after 2 minutes or more, it indicates poor fluidity or no fluidity.

[0094] Smooth flow: indicated by ●;

[0095] Cannot flow: indicated by ○.

[0096] 5. Film-forming properties —Evaluation of the rubber sheet formed by the spreading and cooling of the adhesive on a rotating drum (15-20℃):

[0097] Can form rubber: √

[0098] If the adhesive is too thin to cool and gel, or too viscous and lacks fluidity, a rubber sheet cannot form: ×

[0099] Since the starch film-forming composition cannot form a film and cannot be made into soft capsules, drying time and moisture content cannot be evaluated, indicated by " / ".

[0100] 6. Determination of gelatinized viscosity and phosphate ester group content of acid-treated starch

[0101] In this example, the acid-treated starches were all custom-made and supplied by the starch supplier. Starch suspension preparation: The starch sample was mixed with deionized water at a concentration of 10% w / w and stirred thoroughly until uniformly dispersed, avoiding clumping. Hydration: The suspension was allowed to stand for approximately 30 minutes (at room temperature) to allow the starch particles to fully hydrate and remove air bubbles (centrifugation or vacuum degassing may be necessary). A rotational rheometer (Anton Paar MCR series) was used, with a paddle-type probe and matching container. Temperature control: A Peltier temperature control system or circulating water bath was used to ensure temperature accuracy (±0.1°C). The measurement mode was dynamic oscillation mode. The gelatinization program was a temperature program: 1. Initial temperature: Starting at 50°C, held for 2 minutes to stabilize the baseline. 2. Heating stage: The temperature was increased to 95°C at a rate of 2-5°C / min (simulating the gelatinization process). 3. Holding stage: The temperature was held at 95°C for 5-10 minutes, and the viscosity was observed to stabilize. 4. Cooling Stage (Optional): Cool to 50°C at 1-2°C / min to study retrogradation behavior. Data Acquisition: Continuously record temperature, G', G'', tanδ (=G'' / G'), or apparent viscosity. Key Parameters and Gelatinization Characteristics: Gelatinization Onset Temperature (Tonset): The temperature at which G' or viscosity begins to rise significantly (determined by the tangent method); Gelatinization Peak Temperature (Tpeak): The temperature at which viscosity or G' reaches its maximum value; Gelatinization Enthalpy (ΔH): Requires verification using DSC; cannot be directly measured by a rheometer; Final Viscosity: The viscosity value at the end of heat treatment, reflecting the thermal stability of the starch paste.

[0102] The content of phosphate ester groups in acid-treated starch was determined by phosphorus content, as per national standard GB 5009.87-2016 "National Food Safety Standard - Determination of Phosphorus in Food".

[0103] 7. Soft Capsule Preparation

[0104] Water and plasticizer are mixed to obtain a premix. This premix is ​​then heated and mixed with acid-treated starch at 90-95°C for 1-1.5 hours to obtain a glue solution. Under gravity, the glue solution is conveyed from a storage tank to the left and right glue boxes of a soft capsule filling machine. It is stretched and cooled on a rotating drum (15-20°C) to form a rubber sheet. During the mold cutting and sewing process, algae oil is filled to form soft capsules. The formed soft capsules are dried at 20-25°C and 10-30% humidity for 4-10 hours until the moisture content reaches 9-15%, thus obtaining the soft capsules.

[0105] Example 1: Effect of film-forming composition formulation on measurement results

[0106] According to the formulations (in parts by weight) of compositions 1-5 and comparative examples 1-2 in Table 1, as described above, " Soft capsule preparationThe method describes the formation of a gel shell, with algal oil as the core liquid, to prepare algal oil soft capsules. The drying environment is 22°C and 20% humidity. The fluidity, film-forming properties, drying time, moisture content uniformity, and stability of these film-forming compositions were investigated and evaluated.

[0107] Table 1: Formulations and test results of compositions 1-5 (formulations of compositions and control examples are expressed in parts by weight).

[0108] composition Compare with Example 1 Composition 1 Composition 2 Composition 3 Composition 4 Composition 5 Compare with Example 2 Acid-treated potato starch gelatinization viscosity: 16 mPa·s; phosphorus content: 0.06%. 61.50 66.05 107.35 136.88 187.86 271.82 307.00 glycerin 100.00 100.00 100.00 100.00 100.00 100.00 100.00 water 85 85 85 85 85 85 85 Liquidity ● ● ● ● ● ● ○ Film-forming properties × √ √ √ √ √ × Drying time (hours) / 8 8 6 6 5 / Moisture content at sampling point 1 of tray 1 / 14.26% 12.98% 13.55% 13.14% 12.56% / Moisture content at sampling point 2 in tray 1 / 14.23% 13.02% 13.51% 13.16% 12.63% / Moisture content at sampling point 3 in tray 1 / 14.28% 13.03% 13.60% 13.09% 12.55% / Moisture content at sampling point 4 in tray 1 / 14.35% 12.95% 13.58% 13.18% 12.54% / Moisture content at sampling point 5 in tray 1 / 14.33% 12.98% 13.51% 13.14% 12.56% / Moisture content at sampling point 1 of tray 15 / 14.28% 13.03% 13.51% 13.11% 12.55% / Moisture content at sampling point 2 (15th tray) / 14.25% 13.04% 13.53% 13.14% 12.58% / Moisture content at sampling point 3 of tray 15 / 14.27% 13.01% 13.57% 13.13% 12.65% / Moisture content at sampling point 4 of tray 15 / 14.31% 12.99% 13.56% 13.14% 12.51% / Moisture content at sampling point 5 of tray 15 / 14.34% 12.99% 13.54% 13.11% 12.55% / Moisture content at sampling point 1 of tray 30 / 14.29% 12.99% 13.58% 13.19% 12.57% / Moisture content at sampling point 2 of tray 30 / 14.27% 12.97% 13.56% 13.17% 12.56% / Moisture content at sampling point 3 of tray 30 / 14.27% 13.01% 13.56% 13.16% 12.58% / Moisture content at sampling point 4 of tray 30 / 14.31% 12.96% 13.58% 13.16% 12.61% / Moisture content at sampling point 5 of tray 30 / 14.28% 12.99% 13.57% 13.17% 12.58% / Standard deviation (STDEV) / 0.03% 0.03% 0.03% 0.03% 0.04% / Average / 14.29% 13.00% 13.55% 13.15% 12.57% / Coefficient of variation (CV) / 0.24% 0.21% 0.21% 0.21% 0.28% /

[0109] This embodiment used acid-treated potato starch with a phosphorus content of 0.06% and a gelatinized viscosity controlled at 16 mPa·s. Table 1 shows that for the formulation of Comparative Example 1, using less than 25% acid to treat the starch content resulted in a gel with good flowability, but the gel was too thin to form a film, thus preventing the preparation of soft capsules. For the formulation of Comparative Example 2, using more than 60% acid to treat the starch content resulted in a gel with extremely poor flowability, unable to form a film, and also preventing the preparation of soft capsules.

[0110] For formulations of compositions 1-5, the acid-treated starch content is 25%-60%, resulting in a gel with good fluidity that can form a film. During the preparation of algal oil soft capsules, the drying time is 5-8 hours. The moisture values ​​at five sampling points from the 1st, 15th, and 30th trays (from bottom to top) are similar, with a CV < 10%, indicating highly stable data and excellent uniformity.

[0111] Example 2: Effects of acid-treated starches with different gelatinization viscosities and different phosphate ester group contents on the test results

[0112] According to the proportions of composition 3, and based on the formulations of compositions 6-10 and comparative examples 3-6 in Table 2, as described above... soft capsules preparation The method describes forming a gel shell, using algal oil as the core liquid, to prepare algal oil soft capsules. The drying environment is 20°C and 25% humidity. In this embodiment, a batch of acid-treated starches with different gelatinization viscosities and different phosphate ester group contents were customized. For acid-treated starches with different gelatinization viscosities and different phosphate ester group contents, the flowability, film-forming properties, drying time, moisture uniformity, and stability of these film-forming compositions were investigated and evaluated.

[0113] Table 2: Effects of acid treatment on starches with different gelatinization viscosities and different phosphate ester groups on the determination results

[0114] composition Compare with Example 3 Compare with Example 4 Composition 6 Composition 7 Composition 8 Composition 9 Composition 10 Compare with Example 5 Compare with Example 6 Gelatinized viscosity of acid-treated starch (mPa·s) 4.87 80.34 5.02 65.15 102.51 150.77 195.98 189.73 242.57 Phosphate groups of acid-treated starch (%, based on phosphorus, dry basis). 0.057 0.008 0.037 0.042 0.05 0.011 0.060 0.07 0.053 Liquidity ● ● ● ● ● ● ● ○ ● Film-forming properties × √ √ √ √ √ √ × √ Drying time (hours) / 10 6 6 6 6 6 / 10 Moisture content at sampling point 1 of tray 1 / 18.54% 13.02% 13.21% 13.56% 13.84% 13.78% / 16.66% Moisture content at sampling point 2 in tray 1 / 21.19% 12.99% 13.18% 13.58% 13.79% 13.86% / 22.15% Moisture content at sampling point 3 in tray 1 / 26.78% 13.01% 13.19% 13.61% 13.78% 13.79% / 25.34% Moisture content at sampling point 4 in tray 1 / 19.50% 13.00% 13.18% 13.58% 13.88% 13.78% / 20.56% Moisture content at sampling point 5 in tray 1 / 17.55% 12.97% 13.19% 13.54% 13.74% 13.84% / 16.85% Moisture content at sampling point 1 of tray 15 / 16.79% 13.01% 13.22% 13.57% 13.85% 13.91% / 15.78% Moisture content at sampling point 2 (15th tray) / 26.78% 13.06% 13.23% 13.58% 13.87% 13.84% / 23.98% Moisture content at sampling point 3 of tray 15 / 27.58% 13.04% 13.17% 13.57% 13.83% 13.83% / 25.56% Moisture content at sampling point 4 of tray 15 / 19.04% 13.02% 13.19% 13.60% 13.84% 13.77% / 24.15% Moisture content at sampling point 5 of tray 15 / 17.89% 12.95% 13.24% 13.64% 13.91% 13.91% / 19.87% Moisture content at sampling point 1 of tray 30 / 17.69% 12.98% 13.19% 13.58% 13.79% 13.79% / 16.78% Moisture content at sampling point 2 of tray 30 / 27.65% 13.07% 13.20% 13.59% 13.77% 13.86% / 26.15% Moisture content at sampling point 3 of tray 30 / 22.88% 13.06% 13.19% 13.62% 13.86% 13.79% / 24.89% Moisture content at sampling point 4 of tray 30 / 21.68% 13.03% 13.24% 13.59% 13.82% 13.84% / 22.08% Moisture content at sampling point 5 of tray 30 / 16.58% 13.01% 13.18% 13.59% 13.77% 13.77% / 18.11% Standard deviation STDEV / 4.14% 0.03% 0.02% 0.02% 0.05% 0.05% / 3.71% Average / 21.21% 13.01% 13.20% 13.59% 13.82% 13.82% / 21.26% Coefficient of variation (CV) / 19.51% 0.26% 0.17% 0.18% 0.35% 0.34% / 17.44%

[0115] Table 2 shows that, for the formulation of Comparative Example 3, the prepared adhesive solution has good fluidity; however, if the solution is too thin, it cannot form a film to create a gel, thus making it unsuitable for preparing soft capsules. For the formulation of Comparative Example 4, after drying the algal oil soft capsules for 10 hours, the moisture content failed to meet the standard. Furthermore, the moisture content of the soft capsules fluctuated greatly from bottom to top in the drying tray, and the moisture content at each of the five sampling points on each drying tray showed significant and uneven fluctuations, with a CV exceeding 15%, indicating instability.

[0116] For the formulation of Comparative Example 5, the adhesive solution had high viscosity and poor flowability, making it impossible to form a film and prepare soft capsules. For the formulation of Comparative Example 6, after drying the algal oil soft capsules for 10 hours, the moisture content failed to meet the standard. Furthermore, the moisture content of the soft capsules fluctuated greatly from bottom to top in the drying tray, and the moisture content of the five sampling points in each drying tray also fluctuated greatly and was uneven, with a CV exceeding 15%, indicating instability.

[0117] For formulations 6-10, the gel has good fluidity and can form a film. The drying time for preparing algal oil soft capsules is approximately 6 hours. The moisture values ​​at five sampling points from the 1st, 15th, and 30th trays (from bottom to top) are similar, with a coefficient of variation (CV) < 10%, indicating highly stable data and excellent uniformity. Compositions 7 and 8, which use 0.04-0.05 (as phosphorus phosphorus) phosphate groups and acid treatment of 65.15-102.51 mPa·s on the starch, yielded the best data stability and uniformity.

[0118] Example 3: The effect of other starch or edible gum components in the film-forming composition on the test results.

[0119] According to the formulations of compositions 11-16 in Table 3, as described above... Soft capsule preparation The method describes the formation of a gel shell, with algal oil as the core liquid, to prepare algal oil soft capsules. The drying environment is 25°C and 15% humidity. The fluidity, film-forming properties, drying time, moisture content uniformity, and stability of these film-forming compositions were investigated and evaluated.

[0120] Compositions 11-16 are made from acid-treated potato starch with a gelatinized viscosity of 15.77 mPa·s and a phosphate ester group content of 0.06% (calculated as phosphorus P). Composition 11 contains hydroxypropyl starch. Composition 12 contains native potato starch. Composition 13 contains carrageenan. Composition 14 contains gellan gum. Composition 15 contains pectin.

[0121] Table 3: Effect of other starch or edible gum components in the film-forming composition on the test results

[0122] composition Composition 11 Composition 12 Composition 13 Composition 14 Composition 15 Composition 16 Acid-treated starch (gelatinized viscosity 15.77 mPa·s) phosphate ester group content (0.06%, based on phosphorus, dry basis) 25.80% 28.00% 32.50% 37.80% 32.60% 35.00% Hydroxypropyl starch 5.50% / / / / / Potato starch / 8.00% / / / / Carrageenan / / 6.50% / / / Gel / / / 3.20% / / pectin / / / / 10.00% / gelatin / / / / / 10.00% glycerin 35.00% 32.00% 30.00% 25.00% 34.00% 30.00% water 33.70% 32.00% 31.00% 34.00% 23.40% 25.00% Liquidity ● ● ● ● ● ● Film-forming properties √ √ √ √ √ √ Drying time (hours) 8 8 6 10 6 8 Moisture content at sampling point 1 of tray 1 14.28% 13.57% 13.24% 13.65% 13.26% 12.78% Moisture content at sampling point 2 of plate 1 14.27% 13.59% 13.26% 13.61% 13.33% 12.69% Moisture content at sampling point 3 in tray 1 14.28% 13.60% 13.19% 13.66% 13.29% 12.79% Moisture content at sampling point 4 of plate 1 14.31% 13.58% 13.28% 13.68% 13.28% 12.76% Moisture content at sampling point 5 in tray 1 14.32% 13.52% 13.24% 13.61% 13.24% 12.74% Moisture content at sampling point 1 of plate 15 14.32% 13.56% 13.21% 13.61% 13.25% 12.65% Moisture content at sampling point 2 of plate 15 14.26% 13.55% 13.24% 13.73% 13.34% 12.75% Moisture content at sampling point 3 of plate 15 14.27% 13.55% 13.23% 13.67% 13.33% 12.78% Moisture content at sampling point 4 of plate 15 14.33% 13.56% 13.24% 13.66% 13.34% 12.77% Moisture content at sampling point 5 of tray 15 14.31% 13.55% 13.21% 13.74% 13.31% 12.81% Moisture content at sampling point 1 of plate 30 14.29% 13.58% 13.19% 13.68% 13.29% 12.69% Moisture content at sampling point 2 of plate 30 14.29% 13.55% 13.27% 13.76% 13.27% 12.66% Moisture content at sampling point 3 of plate 30 14.28% 13.56% 13.26% 13.66% 13.33% 12.69% Moisture content at sampling point 4 of plate 30 14.31% 13.58% 13.26% 13.68% 13.32% 12.75% Moisture content at sampling point 5 of plate 30 14.28% 13.60% 13.19% 13.67% 13.27% 12.77% Standard deviation STDEV 0.02% 0.02% 0.03% 0.05% 0.03% 0.05% Average 14.29% 13.57% 13.23% 13.67% 13.30% 12.74% Coefficient of variation (CV) 0.15% 0.16% 0.23% 0.33% 0.26% 0.39%

[0123] Table 3 shows that for formulations 11-16, the prepared adhesive solution has good flowability and can form a film. The drying time for preparing algal oil soft capsules is 6-10 hours. The moisture values ​​at the five sampling points in the 1st, 15th, and 30th trays from bottom to top are similar, with a CV < 10%, indicating highly stable data and excellent uniformity.

[0124] Example 4: The effect of auxiliary components such as pigments or fragrances in the film-forming composition on the test results.

[0125] According to the formulations of compositions 17-18 in Table 4, algal oil soft capsules were prepared by forming a gel shell using algal oil as the core liquid, as described above. The drying environment was 24°C and 12% humidity. The fluidity, film-forming properties, drying time, moisture content uniformity, and stability of these film-forming compositions were investigated and evaluated.

[0126] Compositions 17-18 are made from acid-treated starch with a gelatinized viscosity of 15.77 mPa·s. Composition 17 contains steviol glycosides and β-carotene natural pigments; composition 18 contains sweet orange oil flavoring.

[0127] Table 4: Effect of auxiliary components (pigments or fragrances) of the film-forming composition on the test results

[0128] composition Composition 17 Composition 18 Phosphate ester group content (0.06%, based on phosphorus, dry basis) of acid-treated potato starch (gelatinized viscosity 15.77 mPa·s). 28.00% 28.00% glycerin 35.00% 35.00% water 36.37% 36.54% Steviosides 0.13% / Sweet orange oil flavoring / 0.46% β-Carotene Natural Pigment 0.50% / Liquidity ● ● Film-forming properties √ √ Drying time (hours) 8 8 Moisture content at sampling point 1 of tray 1 13.58% 14.23% Moisture content at sampling point 2 in tray 1 13.52% 14.31% Moisture content at sampling point 3 in tray 1 13.55% 14.26% Moisture content at sampling point 4 in tray 1 13.56% 14.27% Moisture content at sampling point 5 in tray 1 13.52% 14.26% Moisture content at sampling point 1 of tray 15 13.56% 14.26% Moisture content at sampling point 2 (15th tray) 13.53% 14.29% Moisture content at sampling point 3 of tray 15 13.61% 14.25% Moisture content at sampling point 4 of tray 15 13.58% 14.29% Moisture content at sampling point 5 of tray 15 13.56% 14.30% Moisture content at sampling point 1 of tray 30 13.55% 14.27% Moisture content at sampling point 2 of tray 30 13.55% 14.28% Moisture content at sampling point 3 of tray 30 13.59% 14.27% Moisture content at sampling point 4 of tray 30 13.58% 14.25% Moisture content at sampling point 5 of tray 30 13.60% 14.28% Standard deviation STDEV 0.03% 0.02% Average 13.56% 14.27% Coefficient of variation (CV) 0.20% 0.15%

[0129] Table 4 shows that for compositions 17-18, the prepared adhesive solution has good fluidity and can form a film. The drying time for preparing algal oil soft capsules is approximately 8 hours. The moisture values ​​at the five sampling points in the 1st, 15th, and 30th trays from bottom to top are similar, with a CV < 10%, indicating highly stable data and excellent uniformity.

[0130] Example 5: Effects of different sources of acid-treated starch, different gelatinization viscosities, and different phosphate ester contents on the test results.

[0131] According to the formulations of compositions 19-20 in Table 5, algal oil soft capsules were prepared by forming a gel shell using algal oil as the core liquid, as described above. The drying environment was 25°C and 18% humidity. The fluidity, film-forming properties, drying time, moisture content uniformity, and stability of these film-forming compositions were investigated and evaluated.

[0132] Composition 19 uses acid-treated pea starch with a gelatinized viscosity of 189 mPa·s and a phosphate group content of 0.054% (calculated as phosphorus P). Composition 20 uses acid-treated wheat starch with a gelatinized viscosity of 167 mPa·s and a phosphate group content of 0.046% (calculated as phosphorus P).

[0133] Table 5: Effects of different sources of acid-treated starch, different gelatinization viscosities, and different phosphate ester contents on the determination results.

[0134] composition Composition 19 Composition 20 Acid-treated pea starch gelatinized viscosity: 189 mPa·s; phosphorus content: 0.054%. 158.88 / Acid-treated wheat starch gelatinized viscosity: 167 mPa·s; phosphorus content: 0.046%. / 189.54 glycerin 100.00 100.00 water 85.00 85.00 Liquidity ● ● Film-forming properties √ √ Drying time (hours) 8 6 Moisture content at sampling point 1 of tray 1 14.15% 13.64% Moisture content at sampling point 2 in tray 1 14.21% 13.71% Moisture content at sampling point 3 in tray 1 14.10% 13.66% Moisture content at sampling point 4 in tray 1 14.28% 13.68% Moisture content at sampling point 5 in tray 1 14.31% 13.74% Moisture content at sampling point 1 of tray 15 14.21% 13.71% Moisture content at sampling point 2 (15th tray) 14.03% 13.64% Moisture content at sampling point 3 of tray 15 14.17% 13.73% Moisture content at sampling point 4 of tray 15 14.16% 13.74% Moisture content at sampling point 5 of tray 15 14.24% 13.71% Moisture content at sampling point 1 of tray 30 14.18% 13.59% Moisture content at sampling point 2 of tray 30 14.16% 13.57% Moisture content at sampling point 3 of tray 30 14.16% 13.66% Moisture content at sampling point 4 of tray 30 14.28% 13.72% Moisture content at sampling point 5 of tray 30 14.27% 13.68% Standard deviation STDEV 0.07% 0.05% Average 14.19% 13.68% Coefficient of variation (CV) 0.53% 0.38%

[0135] Table 5 shows that for compositions 19-20, the prepared adhesive solution has good fluidity and can form a film. The drying time for preparing algal oil soft capsules is 6-8 hours. The moisture values ​​at the five sampling points in the 1st, 15th, and 30th trays from bottom to top are similar, with a CV < 10%, indicating highly stable data and excellent uniformity.

[0136] discuss

[0137] This invention addresses the drawbacks of using starch-containing compositions to prepare soft capsules, which suffer from poor fluidity of the liquid, require prolonged drying times (over 24 hours), and necessitate manual turning during the drying process to achieve uniform moisture content. Existing plant-based soft capsule technologies utilize water-retaining agents or physical heating during preparation for rapid drying, but these methods result in uneven moisture distribution and risks such as stickiness and dents. To overcome these shortcomings, this invention controls the gelatinization viscosity of acid-treated starch, mixes it with plasticizers and water in a specific ratio to obtain a highly fluid colloid, forming a starch film-forming composition with a certain gel strength. This composition, when used to make soft capsules, exhibits high water loss efficiency, rapid drying speed (reaching the target moisture content of 9-15% within 5-10 hours), eliminates the need for manual turning, ensures uniform moisture content, and significantly reduces production costs.

[0138] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A starch film-forming composition comprising 25-60 wt% acid-treated starch, 20-40 wt% plasticizer and 15-40 wt% water, wherein the acid-treated starch is acid-treated starch with a gelatinized viscosity of 5-196 mPa·s, and the phosphate content of the acid-treated starch is 0.01-0.06% based on phosphorus.

2. The starch film-forming composition according to claim 1, wherein the acid-treated starch is one or more of acid-treated corn starch, acid-treated pea starch, acid-treated potato starch, and acid-treated wheat starch, and / or Acid-treated starches are amylose and / or amylopectin; and / or Plasticizers are one or more of glycerin, propylene glycol, polyethylene glycol, sorbitol, erythritol, and maltitol; and / or The plasticizer content is 22wt%-38wt%; and / or The water content is 18wt%-37wt%.

3. The starch film-forming composition according to claim 1 or 2, further comprising one or more of a second starch different from acid-treated starch, edible gum, pigment, and flavoring.

4. The starch film-forming composition according to claim 3, wherein the starch film-forming composition satisfies one or more of the following conditions: (1) The second starch is one or more of hydroxypropyl starch, cross-linked starch, acetate starch, oxidized starch and natural starch; (2) The content of secondary starch is 2-8 wt%; (3) The content of pigments and / or flavors is within the acceptable range for soft capsules; (4) Edible gum is one or more of gelatin, carrageenan, agar, sodium alginate, pectin, xanthan gum, and locust bean gum; and (5) The content of edible gum is 0.1-20 wt%.

5. The starch film-forming composition according to claim 1 or 2, wherein the starch film-forming composition does not contain edible gum or the starch film-forming composition does not further contain a water-retaining agent.

6. The starch film-forming composition according to claim 1 or 2, wherein the starch film-forming composition does not contain gelatin or does not contain one or more of trehalose, mannitol and xylitol.

7. A soft capsule shell comprising or prepared from any one of the starch film-forming compositions of claims 1-6, wherein the water content of the soft capsule shell is 9-15 wt%.

8. A method for preparing soft capsules, comprising the following steps: (a) Preparing a glue solution using raw materials comprising the starch film-forming composition of any one of claims 1-6, and forming the glue solution into a rubber sheet. (b) The rubber sheet is prepared into a molded soft capsule, and (c) The shaped soft capsules are dried to a moisture content of less than 15% to obtain soft capsules; wherein the drying time of the shaped soft capsules is less than 10 hours.

9. The method of claim 8, wherein the method satisfies one or more of the following conditions: (i) Drying time is 4-10 hours; (ii) The drying conditions are ambient conditions, or drying conditions with a temperature of 20-25°C and a humidity of 10-30%; (iii) The drying process is carried out under static conditions or without turning the soft capsules; (iv) The drying method is tray drying.

10. The method of claim 8, comprising: A) Mix water and plasticizer to obtain a premix. B) The premix is ​​mixed with acid-treated starch to obtain a gel; C) Prepare molded soft capsules from the gel and dry the molded soft capsules to a moisture content of less than 15%.

11. The method of claim 10, further comprising one or more of the following steps: D) Add one or more of the following in step B): a second starch, edible gum, pigment, and flavoring, which are different from the acid-treated starch; E) The adhesive liquid is delivered to the glue box of the soft capsule filling machine, where it is extended and cooled on the drum to form a rubber sheet. During the mold cutting and sewing process, the contents are filled to form a soft capsule.

12. The method according to claim 11, wherein the method comprises heating the mixture at 90-95°C for 1-1.5 hours to obtain a liquid adhesive; and / or drying the molded soft capsules to 9-15% moisture content; and / or the contents being powdered or liquid active ingredients; and / or conveying the liquid adhesive from a storage tank to a cartridge via a tubing under gravity or under the pressure of compressed air at 0.05-0.1 MPa.

13. A soft capsule comprising a soft capsule shell according to claim 7 or prepared by any one of claims 8-12, and further comprising contents.

14. Use of the soft capsule shell of claim 7 or the soft capsule of claim 13 in food or cosmetics or in the preparation of a medicine.

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