Plant soft capsule and preparation method and application thereof

Abstract

The present disclosure belongs to the technical field of soft capsules, and particularly relates to a plant soft capsule and a preparation method and application thereof. The plant soft capsule with excellent performance is prepared from carrageenan, starch, a plasticizer and water by controlling the weight-average molecular weight of the carrageenan to be 1.2×10.sup.6 to 2.0×10.sup.6. Compared with a plant soft capsule in the existing technology, the plant soft capsule of the present discourse has lower production cost, and the product quality meets the requirements of gelatin soft capsules; and on the premise of high production efficiency, a low oil leakage rate is achieved, and the rupture time meets United States Pharmacopoeia (USP) standards. The plant soft capsule prepared according to the present disclosure can be filled with an active component as a content and used for preparation of a plurality of drugs, functional food or dietary nutritional supplements.

Claims

1. A preparation method of plant soft capsules, comprising the following steps: 1) gum dissolving process: weighing carrageenan, starch, a plasticizer, a pigment, and water in a formula amount to obtain a mixture, heating until the mixture swells at 80 to 90° C., preserving heat for 20 to 120 minutes, and degassing until the mixture is clear and transparent to obtain a gum solution; and 2) pill rolling process: heating a gum box of a pill rolling machine at 80 to 95° C., heating a rotary drum at 20 to 40° C., supplying the gum solution to the pill rolling machine, setting a thickness of a gum skin to be 0.30 to 0.60 mm, rolling the gum solution to obtain the plant soft capsules after setting a machine speed of the pill rolling machine, drying until the plant soft capsules reach a certain hardness, selecting the plant soft capsules, and finally packaging the plant soft capsules, wherein the weight-average molecular weight Mw of the carrageenan is 1.2×10.sup.6 to 2.0×10.sup.6 daltons, and the carrageenan is an iota-carrageenan or a combination of the iota-carrageenan and the kappa-carrageenan; and in the combination of the iota-carrageenan and the kappa-carrageenan, the iota-carrageenan:the kappa-carrageenan is calculated to be 9.9:0.1 to 7.0:3.0 according to weight ratio, wherein the plasticizer is selected from the group consisting of glycerin and sorbitol, wherein the starch is selected form the group consisting of hydroxypropyl starch and oxidized hydroxypropyl starch, and wherein the pigment is selected from the group consisting of annatto and spirulina blue.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a detection diagram of typical commercial carrageenan with high molecular weight, wherein the weight-average molecular weight Mw=2.40×10.sup.6.

(2) FIG. 2 is a detection diagram of typical commercial carrageenan with low molecular weight, wherein the weight-average molecular weight Mw=1.12×10.sup.6.

(3) FIG. 3 is a detection diagram of typical carrageenan with limited molecular weight according to the present disclosure, wherein the weight-average molecular weight Mw=1.78×10.sup.6.

(4) In FIGS. 1-3, the horizontal axis represents a logarithm of the molecular weight; and the vertical axis represents that a vertical axis value of a point on the curve is a numerical value related to content of sample molecules at each molecular weight

DETAILED DESCRIPTION OF THE INVENTION

(5) For the purpose of making objectives, technical schemes and advantages of the present disclosure clearer, further detailed description will be made to the present disclosure in conjunction with specific embodiments. It should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present disclosure.

(6) Devices involved in embodiments: gum dissolving tank TRRJ-10, from Wenzhou Tianrui Pharmaceutical Machinery Co., Ltd.; full-automatic soft capsule machine BCM-GB6, from BOCHANG Co., Ltd.; and SLX-A hardness tester, from Wenzhou Shandu Instrument Co., Ltd.

(7) Main Detection Indexes of Soft Capsules:

(8) 1) gum skin joint rate: a ratio of the joint thickness of gum skins to the thickness of the gum skins; 2) oil leakage rate: a ratio of soft capsules leaking oil to all soft capsules; 3) content loading capacity: the maximum loading capacity of a mold; 4) rupture time: referring to a rupture experiment in USP <2040>; and 5) hardness: the hardness of dried soft capsules, for measurement of the drying effect of the soft capsules.

Embodiment 1

(9) Influence of Different Types of Carrageenan on Prepared Soft Capsules

(10) 1) Gum Dissolving Process

(11) 8 KG of different types of carrageenan, 30 KG of hydroxypropyl starch, 15 KG of glycerin and 47 KG of purified water were weighed, put in a gum dissolving tank and heated to 80 to 90° C. to enable a gum solution to swell, then heat was preserved for 20 to 120 min, and degassing was performed until the gum solution was clear and transparent to obtain the gum solution.

(12) 2) Pill Rolling Process

(13) A 22-minim cylindrical soft capsule mold was selected, a gum box of a pill rolling machine was heated to 80 to 95° C., a rotary drum was heated to 20 to 40° C., gum was supplied, the thickness of gum skins was set to be 0.80 mm, pill rolling was performed at a machine speed of 1.5 rpm, the content was linseed oil, pills were dried until the hardness of the gum pills met the requirement (50 to 70 N), and the pills were selected and finally packaged.

(14) The gum skin joint rate, the content loading capacity and the oil leakage rate of soft capsules prepared from the different types of carrageenan were detected, and the result is shown in Table 1.

(15) TABLE-US-00001 TABLE 1 Influence of Types of Carrageenan on Products Carrageenan I type K type L type I type + K type Gum skin joint rate 70%  0%  0% 75% Content loading capacity 800 mg 0 0 850 mg Oil leakage rate Less 100% 100% Less than 1% than 1%

(16) Note: in Table 1, the weight-average molecular weight of I-type carrageenan is 1.2×10.sup.6, the weight-average molecular weight of K-type carrageenan is 2.0×10.sup.6, and the weight-average molecular weight of L-type carrageenan is 1.8×10.sup.6; and I type+K type means that the I-type carrageenan and the K-type carrageenan are used as raw materials, and the weight ratio of the I type: the K type is calculated and may be in the range of 9.9:0.1 to 7.0:3.0, and is 8:1 in the present embodiment.

(17) It is found in the experiment that the gum solution prepared from the L-type carrageenan has no gelation performance and cannot be spread to form a film, and the gum solution prepared from the pure K-type carrageenan has good film forming property but poor viscosity. Only the gum solution prepared from the pure I-type or I-type+K-type carrageenan is easy to spread to form a film and moderate in viscosity, the gum skins are good in toughness and not easy to break, the oil leakage rate of the produced capsules is low, and the production efficiency is high.

Embodiment 2

(18) Influence of Carrageenan With Different Weight-Average Molecular Weights on Prepared Soft Capsules

(19) 1) Gum Dissolving Process

(20) 8 KG of I-type (Iota) carrageenan with different weight-average molecular weights, 30 KG of hydroxypropyl starch, 15 KG of glycerin and 47 KG of purified water were weighed, put in a gum dissolving tank and heated to 80 to 90° C. to enable a gum solution to swell, then heat was preserved for 20 to 120 min, and degassing was performed until the gum solution was clear and transparent to obtain the gum solution.

(21) 2) Pill Rolling Process

(22) A 22-minim cylindrical soft capsule mold was selected, a gum box of a pill rolling machine was heated to 80 to 95° C., a rotary drum was heated to 20 to 40° C., gum was supplied, the thickness of gum skins was set to be 0.80 mm, pill rolling was performed at a machine speed of 1.5 rpm, the content was linseed oil, pills were dried until the hardness of the gum pills met the requirement (50 to 70 N), and the pills were selected and finally packaged.

(23) The gum skin joint rate, the content loading capacity and the oil leakage rate of soft capsules prepared from the carrageenan with different weight-average molecular weights were detected, and the result is shown in Table 2.

(24) TABLE-US-00002 TABLE 2 Influence of Weight-average Molecular Weights of Carrageenan on Products Carrageenan Mw 1.0 × 10.sup.6 1.2 × 10.sup.6 1.5 × 10.sup.6 2.0 × 10.sup.6 2.5 × 10.sup.6 Gum skin joint rate 40% 60% 70% 50% 20% Content loading capacity 600 mg 800 mg 850 mg 800 mg 400 mg Oil leakage rate 20% Less than 1% Less than 1% Less than 1% 50%

(25) It is found in the experiment that when the proportion of carrageenan with small molecular weight is too high, the viscosity of the gum skins is strong, but the film forming property is poor, resulting in low loading capacity and high oil leakage rate. When the proportion of carrageenan with high molecular weight is too high, the film forming property of the gum solution is good, and the gum solution can be uniformly spread on the surface of the rotary drum, but the viscosity of the gum skins is poor, the joint rate is low, and the oil leakage of the rolled pills is obvious. Only when the weight-average molecular weight of the carrageenan is stable between 1.20×10.sup.6 and 2.00×10.sup.6, the gum solution is easy to spread to form a film and moderate in viscosity, the gum skins are good in toughness and not easy to break, and the production efficiency is high.

Embodiment 3

(26) Influence of Different Rotary Drum Temperatures on Properties of Prepared Soft Capsules

(27) 1) Gum Dissolving Process

(28) 8 KG of I-type (Iota) carrageenan (the weight-average molecular weight of the carrageenan is 1.50±0.1×10.sup.6), 30 KG of hydroxypropyl starch, 15 KG of glycerin and 47 KG of purified water were weighed, put in a gum dissolving tank and heated to 80 to 90° C. to enable a gum solution to swell, then heat was preserved for 20 to 120 min, and degassing was performed until the gum solution was clear and transparent to obtain the gum solution.

(29) 2) Pill Rolling Process

(30) A 22-minim cylindrical soft capsule mold was selected, a gum box of a pill rolling machine was heated to 80 to 95° C., a rotary drum was heated, gum was supplied, the thickness of gum skins was set to be 0.80 mm, pill rolling was performed at a machine speed of 1.5 rpm, the content was linseed oil, pills were dried until the hardness of the gum pills met the requirement (50 to 70 N), and the pills were selected and finally packaged.

(31) The gum skin joint rate, the content loading capacity and the oil leakage rate of soft capsules prepared at different rotary drum temperatures were detected, and the result is shown in Table 3.

(32) TABLE-US-00003 TABLE 3 Influence of Different Rotary Drum Temperatures on Products Rotary drum temperature 15° C. 20° C. 30° C. 40° C. 50° C. Gum skin joint rate 50% 60% 70% 70% 40% Content loading capacity 600 mg 800 mg 850 mg 850 mg 700 mg Oil leakage rate 20% Less than 1% Less than 1% Less than 1% 40%

(33) Different rotary drum temperatures have a great influence on the toughness of the gum skins, and at present, rotary drums of pill rolling machines in the industry are all refrigerated, so that a gelatin solution is cooled and formed as soon as possible, but the moisture content of the plant gum solution of the present disclosure is high and is difficult to dry quickly by a conventional refrigeration method to form gum skins with good toughness. The rotary drum is heated, the plant gum skins which pass the rotary drum with the heating function can be dried quickly, the toughness and the viscosity are good, and the early drying time is saved. Through the experiment, it is found that when the rotary drum temperature is low, the gum skins are dried slowly and the toughness is not enough, resulting in lower loading capacity and high oil leakage rate. When the rotary drum temperature is high, the water loss of the gum skins is too fast, so that the viscosity of the gum skins is reduced, the joint rate is low, and finally oil leakage is caused. Thus the preferred rotary drum temperature range is 20 to 40° C.

Embodiment 4

(34) Influence of Different Plasticizers on Properties of Prepared Soft Capsules

(35) 1) Gum Dissolving Process

(36) 8 KG of I-type (Iota) carrageenan (the weight-average molecular weight of the carrageenan was 1.50±0.1×10.sup.6), 30 KG of hydroxypropyl starch, 15 KG of a plasticizer and 47 KG of purified water were weighed, put in a gum dissolving tank and heated to 80 to 90° C. to enable a gum solution to swell, then heat was preserved for 20 to 120 min, and degassing was performed until the gum solution was clear and transparent to obtain the gum solution.

(37) 2) Pill Rolling Process

(38) A 22-minim cylindrical soft capsule mold was selected, a gum box of a pill rolling machine was heated to 80 to 95° C., a rotary drum was heated to 20 to 40° C., gum was supplied, the thickness of gum skins was set to be 0.80 mm, pill rolling was performed at a machine speed of 1.5 rpm, the content was linseed oil, pills were dried until the hardness of the gum pills met the requirement (50 to 70 N), and the pills were selected and finally packaged.

(39) The gum skin joint rate, the content loading capacity and the oil leakage rate of soft capsules prepared from different plasticizers were detected, and the result is shown in Table 4.

(40) TABLE-US-00004 TABLE 4 Influence of Different Plasticizers on Products Plasticizer Glycerin Sorbitol Xylitol Polyethylene glycol Gum skin joint rate 70% 60% 40% 30% Content loading capacity 850 mg 700 mg 500 mg 400 mg Oil leakage rate Less Less 20% 40% than 1% than 1%

(41) The plasticizers have a great influence on the toughness of the gum skins, the toughness of the gum skins determines the loading capacity range of capsules, and the better the toughness is, the larger the loading capacity is. Glycerin, sorbitol, xylitol and polyethylene glycol were tested as plasticizers, and it is found that glycerin gum skins have the best toughness, the loading capacity of the capsules can be up to 850 mg, when the sorbitol, the xylitol or the polyethylene glycol is used as the plasticizer for the same mold, the gum skin toughness is insufficient, the loading capacity of the capsules is low, and when the xylitol and the polyethylene glycol are used as plasticizers, the oil leakage rate is high, so the glycerin is preferred as the gum skin plasticizer.

Embodiment 5

(42) Influence of Different Starch Types on Properties of Prepared Soft Capsules

(43) 1) Gum Dissolving Process

(44) 8 KG of I-type (Iota) carrageenan (the weight-average molecular weight of the carrageenan was 1.50±0.1×10.sup.6), 30 KG of starch, 15 KG of glycerin and 47 KG of purified water were weighed, put in a gum dissolving tank and heated to 80 to 90° C. to enable a gum solution to swell, then heat was preserved for 20 to 120 min, and degassing was performed until the gum solution was clear and transparent to obtain the gum solution.

(45) 2) Pill Rolling Process

(46) A 22-minim cylindrical soft capsule mold was selected, a gum box of a pill rolling machine was heated to 80 to 95° C., a rotary drum was heated to 20 to 40° C., gum was supplied, the thickness of gum skins was set to be 0.80 mm, pill rolling was performed at a machine speed of 1.5 rpm, the content was linseed oil, pills were dried until the hardness of the gum pills met the requirement (50 to 70 N), and the pills were selected and finally packaged.

(47) The gum skin joint rate, the content loading capacity and the oil leakage rate of soft capsules prepared from different types of starch were detected, and the result is shown in Table 5.

(48) TABLE-US-00005 TABLE 5 Influence of Different Starch on Products Starch Oxidized Acidic Hydroxypropyl Oxidized hydroxypropyl starch starch starch starch Gum skin joint rate 10% 20% 70% 70% Content loading capacity 300 mg 500 mg 850 mg 900 mg Oil leakage rate 80% 60% Less than 1% Less than 1%

(49) The starch has a great influence on the viscosity of the gum skins, when the viscosity of the gum skins is too low, the joint thickness is insufficient and the oil leakage rate is high, and when the viscosity of the gum skins is too high, the gum skins is easy to adhere to the surface of the rotary drum, and the production efficiency is influenced. Therefore, oxidized starch, acidic starch, hydroxypropyl starch and oxidized hydroxypropyl starch were screened and tested respectively, it is found that the viscosity of gum skins prepared from the oxidized starch and the acidic starch is insufficient, and the prepared capsules is very easy to leak oil; the hydroxypropyl starch and the oxidized hydroxypropyl starch have good viscosity and meet the production requirements, so that the hydroxypropyl starch or the oxidized hydroxypropyl starch are preferred.

Embodiment 6

(50) Influence of Different Thicknesses of Gum Skins on Properties of Products

(51) 1) Gum Dissolving Process

(52) 8 KG of I-type (Iota) carrageenan (the weight-average molecular weight of the carrageenan was 1.50±0.1×10.sup.6), 30 KG of hydroxypropyl starch, 15 KG of glycerin and 47 KG of purified water were weighed, put in a gum dissolving tank and heated to 80 to 90° C. to enable a gum solution to swell, then heat was preserved for 20 to 120 min, and degassing was performed until the gum solution was clear and transparent to obtain the gum solution.

(53) 2) Pill Rolling Process

(54) A 22-minim cylindrical soft capsule mold was selected, a gum box of a pill rolling machine was heated to 80 to 95° C., a rotary drum was heated to 20 to 40° C., gum was supplied, the gum skins were set to be in different thicknesses, pill rolling was performed at a machine speed of 1.5 rpm, the content was linseed oil, pills were dried until the hardness of the gum pills met the requirement (50 to 70 N), and the pills were selected and finally packaged.

(55) The gum skin joint rate, the content loading capacity, the oil leakage rate, the rupture time and hardness of soft capsules prepared from the gum skins in different thicknesses were detected, and the result is shown in Table 6.

(56) TABLE-US-00006 TABLE 6 Influence of Different Thicknesses of Gum Skins on Products Gum skin thickness 0.20 0.30 0.45 0.60 0.80 Gum skin joint rate 70% 70% 70% 70% 70% Content loading capacity 750 mg 1000 mg 1000 mg 950 mg 850 mg Oil leakage rate 5% Less than 1% Less than 1% Less than 1% Less than 1% Rupture time 1 min 3 min 5 min 13 min 25 min Hardness 30N 50N 70N 70N 70N

(57) The data show that gum skins in the thickness of 0.30 mm to 0.60 mm can be prepared on the premise of meeting the above performance indexes. Theoretically, the thicker the gum skins, the better, but the thinner the gum skins are, the higher the risk of oil leakage is, so in order to control the oil leakage rate, the conventional gum skin thickness in the industry is 0.70 mm to 0.90 mm. However, by adjusting the formula of the soft capsules and combining the production process of the present disclosure, on the premise of ensuring the oil leakage rate of the products, the thickness of the gum skins can be 0.30 mm to 0.60 mm. When the thickness of the gum skins is large, the oil leakage rate of the capsules is low, but the rupture time is too long, and the cost of the gum skins is too high; when the thickness of the gum skins is too small, the rupture time is short, but the oil leakage rate of the capsules is high, the capsules are too soft, and the hardness is not enough. The preferred thickness of the gum skins is 0.30 mm to 0.60 mm by comprehensively considering the cost and the oil leakage rate.

Embodiment 7

(58) Influence of Different Machine Speeds on Properties of Products

(59) 1) Gum Dissolving Process

(60) 8 KG of I-type (Iota) carrageenan (the weight-average molecular weight of the carrageenan was 1.50±0.1×10.sup.6), 30 KG of hydroxypropyl starch, 15 KG of glycerin and 47 KG of purified water were weighed, put in a gum dissolving tank and heated to 80 to 90° C. to enable a gum solution to swell, then heat was preserved for 20 to 120 min, and degassing was performed until the gum solution was clear and transparent to obtain the gum solution.

(61) 2) Pill Rolling Process

(62) A 22-minim cylindrical soft capsule mold was selected, a gum box of a pill rolling machine was heated to 80 to 95° C., a rotary drum was heated to 20 to 40° C., gum was supplied, the thickness of gum skins was set to be 0.40 mm, pill rolling was performed at different machine speeds, the content was linseed oil, pills were dried until the hardness of the gum pills met the requirement (50 to 70 N), and the pills were selected and finally packaged.

(63) The gum skin joint rate, the content loading capacity and the oil leakage rate of soft capsules prepared at the different machine speeds were detected, and the result is shown in Table 7.

(64) TABLE-US-00007 TABLE 7 Influence of Different Machine Speeds on Products Machine speed 1.5 rpm 2.5 rpm 3.0 rpm 4.0 rpm 5.0 rpm Gum skin joint rate 80% 75% 70% 60% 50% Content loading capacity 1000 mg 1000 mg 1000 mg 1000 mg 1000 mg Oil leakage rate Less than 1% Less than 1% Less than 1% Less than 1% Less than 1%

(65) Conventional plant soft capsule production considers the problem of the oil leakage rate, the machine speed is generally relatively low, and it can also be seen from the joint rate of a gum solution that a joint is relatively perfect and the risk of oil leakage is low. However, the production efficiency at a low speed is low, while a plant soft capsule production process of the present disclosure can achieve the approximate gum skin joint rate at the machine speed of 1.5 to 5.0 rpm, the oil leakage rate is less than 1%, and the plant soft capsule production process has extremely high production efficiency.

Embodiment 8

(66) Influence of Different Ions on Properties of Products

(67) 1) Gum Dissolving Process

(68) 8 KG of I-type (Iota) carrageenan (the weight-average molecular weight of the carrageenan was 1.50±0.1×10.sup.6), 30 KG of hydroxypropyl starch, 15 KG of glycerin, 0.1 KG of ions (if necessary) and 47 KG of purified water were weighed, put in a gum dissolving tank and heated to 80 to 90° C. to enable a gum solution to swell, then heat was preserved for 20 to 120 min, and degassing was performed until the gum solution was clear and transparent to obtain the gum solution.

(69) 2) Pill Rolling Process

(70) A 22-minim cylindrical soft capsule mold was selected, a gum box of a pill rolling machine was heated to 80 to 95° C., a rotary drum was heated to 20 to 40° C., gum was supplied, the thickness of gum skins was set to be 0.40 mm, pill rolling was performed at a machine speed of 3.0 rpm, the content was linseed oil, pills were dried until the hardness of the gum pills met the requirement (50 to 70 N), and the pills were selected and finally packaged.

(71) The gum skin joint rate, the content loading capacity, the oil leakage rate and the rupture time of soft capsules prepared from the different ions were detected, and the result is shown in Table 8.

(72) TABLE-US-00008 TABLE 8 Influence of Different Ions on Products Ion Sodium chloride Potassium chloride Calcium chloride No ion Gum skin joint rate 90% 85% 85% 70% Content loading capacity 1000 mg 1000 mg 1000 mg 1000 mg Oil leakage rate Less than 1% Less than 1% Less than 1% Less than 1% Rupture time 18 min 20 min 25 min 5 min

(73) In the existing technology, calcium chloride, potassium chloride, sodium chloride and other ions are used as film-forming agents to promote cross-linking of carrageenan so as to realize excellent film forming property and ensure the toughness of gum skins; and it is found in the study of the present disclosure that the addition of the film-forming agents results in too long capsule rupture time far exceeding 15 minutes. According to the present disclosure, the soft capsules with equivalent or even better performance (basically the same toughness as measured by the content loading capacity) can be prepared without adding any metal ions, and the rupture time is obviously shortened and completely meets the USP standards.

Embodiment 9

(74) Influence of Different Pigments on Properties of Products

(75) 1) Gum Dissolving Process

(76) 8 KG of I-type (Iota) carrageenan (the weight-average molecular weight of the carrageenan was 1.50±0.1×10.sup.6), 30 KG of hydroxypropyl starch, 15 KG of glycerin, 1 KG of pigments and 47 KG of purified water were weighed, put in a gum dissolving tank and heated to 80 to 90° C. to enable a gum solution to swell, then heat was preserved for 20 to 120 min, and degassing was performed until the gum solution was clear and transparent to obtain the gum solution.

(77) 2) Pill Rolling Process

(78) A 22-minim cylindrical soft capsule mold was selected, a gum box of a pill rolling machine was heated to 80 to 95° C., a rotary drum was heated to 20 to 40° C., gum was supplied, the thickness of gum skins was set to be 0.40 mm, pill rolling was performed at a machine speed of 3.0 rpm, the content was linseed oil, pills were dried until the hardness of the gum pills met the requirement (50 to 70 N), and the pills were selected and finally packaged.

(79) The result of properties of soft capsules prepared from the different pigments is shown in Table 9.

(80) TABLE-US-00009 TABLE 9 Influence of Different Pigments on Products Spiru- Purple Red Cara- An- lina sweet iron Car- Pigment mel natto blue potato red oxide mine Appearance Brown Orange Blue Purple red Red brown Red Fade Not Not Not Fade Not Not or not fade fade fade fade fade Gum Poor Good Good Good Poor Good solution performance

(81) Because the production process of the plant soft capsule is high in temperature and conventional pigments are extremely easy to fade at high temperature, screening of the pigments with resistance to high temperature and meeting production requirements has extremely important significance. According to the present disclosure, the influence of various pigments on the performance of the gum solution was tested, and it is found that when the adding proportion of caramel is high, the viscosity of the gum solution is very strong, but the performance of the gum solution is poor, and the gum solution cannot be spread to form a film. Purple sweet potato red can meet production requirements, but this natural pigment is extremely easy to fade at high temperature. Although red iron oxide does not fade at high temperature, the gum solution has poor performance. After screening for many times, it is found that annatto and spirulina blue do not affect the performance of the gum solution, and do not fade at high temperature for a certain time, which is of great significance for enriching product types.

(82) In Table 9, the purple sweet potato red (also known as a purple sweet potato red pigment) is a natural red pigment extracted from roots, stems and leaves of purple sweet potatoes, and the structure of the purple sweet potato red contains a plurality of phenolic hydroxyl groups. The stability of the purple sweet potato red pigment was studied in detail in the existing technology (Food Processing, No. 2, Vol. 41, 2016, pages 38-41, Research on Stability of Purple Sweet Potato Red Pigment), and the research shows that Al3.sup.+, Ca2.sup.+ and Sn2.sup.+ are the best for the stability of the purple sweet potato red pigment, but the addition of metal ions in the system of the present disclosure has a great influence on the rupture time of the soft capsules. In addition, the article shows that the metal ion types may have an adverse effect on accelerating the color fading, so the reference significance is not great.

(83) In order to develop a purple red soft capsule and solve the problem of discoloration of the purple sweet potato red during preparation of the soft capsule, different kinds of food additives were researched to serve as color fixatives of the purple sweet potato red, and it is found that meglumine can effectively solve the problem of fading of the purple sweet potato red; a preparation method of a soft capsule added with a color fixative differs from the screening method of the pigments in that the purple sweet potato red was selected as the pigment, the color fixative with the weight of 50 wt % (namely 500 g) of the purple sweet potato red was added, and the color of soft capsule shells prepared from different color fixatives was taken as a measure of the color fixative effects of the color fixatives. The result is shown in Table 9-A.

(84) TABLE-US-00010 TABLE 9-A Color Fixative effects of Different Color Fixatives Color change of soft capsule shells at different stages Accelerate for 3 Color fixative 0 day months at 40° C. ND Basically colorless — Ascorbic acid Basically colorless — Citric acid Basically colorless — Glucose Light purple Basically colorless L-cysteine Purple red Become dark red hydrochloride after two months Meglumine Purple red Purple red Sodium benzoate Basically colorless —

(85) Note: ND means that no color fixative is added as a contrast; ‘’ means not tested; 0 day refers to soft capsules prepared on the same day; accelerate for 3 months at 40° C. means that the prepared soft capsules are packaged by PVC plastic bottles (simulating commercial packages) and placed in the dark for 3 months at a temperature of (40±2)° C., and the color change of the capsule shells is observed.

(86) The experiment result shows that acid color fixatives (ascorbic acid and citric acid) and organic acid salts (sodium benzoate) basically have no color fixative effect on the purple sweet potato red in the system; glucose has a weak color fixative effect, only L-cysteine hydrochloride and meglumine have obvious color fixative effects, but only meglumine has an excellent long-term color fixative effect when an accelerated test is adopted for evaluating the long-term placement, and can really have the prospect of industrial application.

Embodiment 10

(87) 1) Gum Dissolving Process

(88) 8 KG of I type (Iota) carrageenan (the weight-average molecular weight of the carrageenan was 1.50±0.1×10.sup.6), 30 KG of hydroxypropyl starch, 15 KG of glycerin and 47 KG of purified water were weighed, put in a gum dissolving tank and heated to 80 to 90° C. to enable a gum solution to swell, then heat was preserved for 20 to 120 min, and degassing was performed until the gum solution was clear and transparent to obtain the gum solution.

(89) 2) Pill Rolling Process

(90) A 22-minim cylindrical soft capsule mold was selected, a gum box of a pill rolling machine was heated to 80 to 95° C., a rotary drum was heated to 20 to 40° C., the gum was supplied, the thickness of gum skins was set to be 0.40 mm, pill rolling was performed at a machine speed of 3.0 rpm, the content was linseed oil, pills were dried until the hardness of the gum pills met the requirement (50 to 70 N), and the pills were selected and finally packaged.

(91) The rupture time of an obtained finished product is 5 min, an oil leakage rate is controlled to be less than 1%, and the process has extremely high production efficiency and meets the USP standards.

Embodiment 11

(92) 1) Gum Dissolving Process

(93) 3 KG of I type (Iota) carrageenan (the weight-average molecular weight of the carrageenan was 1.50±0.1×10.sup.6), 40 KG of hydroxypropyl starch, 20 KG of glycerin and 37 KG of purified water were weighed, put in a gum dissolving tank and heated to 80 to 90° C. to enable a gum solution to swell, then heat was preserved for 20 to 120 min, and degassing was performed until the gum solution was clear and transparent to obtain the gum solution.

(94) 2) Pill Rolling Process

(95) A 22-minim cylindrical soft capsule mold was selected, a gum box of a pill rolling machine was heated to 80 to 95° C., a rotary drum was heated to 20 to 40° C., the gum was supplied, the thickness of gum skins was set to be 0.40 mm, pill rolling was performed at a machine speed of 3.0 rpm, the content was linseed oil, pills were dried until the hardness of the gum pills met the requirement (50 to 70 N), and the pills were selected and finally packaged.

(96) The obtained detection result is shown in Table 11:

(97) TABLE-US-00011 TABLE 11 Soft Capsule Detection Result Gum skin joint rate 70% Content loading capacity 800 mg Oil leakage rate Less than 1% Rupture time 3 min Hardness 55N

Embodiment 12

(98) 1) Gum Dissolving Process

(99) 15 KG of I type (Iota) carrageenan (the weight-average molecular weight of the carrageenan was 1.50±0.1×10.sup.6), 20 KG of hydroxypropyl starch, 10 KG of glycerin and 55 KG of purified water were weighed, put in a gum dissolving tank and heated to 80 to 90° C. to enable a gum solution to swell, then heat was preserved for 20 to 120 min, and degassing was performed until the gum solution was clear and transparent to obtain the gum solution.

(100) 2) Pill Rolling Process

(101) A 22-minim cylindrical soft capsule mold was selected, a gum box of a pill rolling machine was heated to 80 to 95° C., a rotary drum was heated to 20 to 40° C., the gum was supplied, the thickness of gum skins was set to be 0.40 mm, pill rolling was performed at a machine speed of 3.0 rpm, the content was linseed oil, pills were dried until the hardness of the gum pills met the requirement (50 to 70 N), and the pills were selected and finally packaged.

(102) The obtained detection result is shown in Table 12:

(103) TABLE-US-00012 TABLE 12 Soft Capsule Detection Result Gum skin joint rate 60% Content loading capacity 750 mg Oil leakage rate Less than 1% Rupture time 6 min Hardness 65N

(104) Although the embodiments of the present disclosure have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the present disclosure.