Solid beverages in China started late, but have developed quite rapidly in recent years. Effervescent tablet solid beverage is widely used, and its convenient storage and drinking methods, unique flavor, rich taste, and more comprehensive nutrients make it a beverage product that meets the requirements of modern people.

When the effervescent tablet solid drink is put into drinking water, under the action of effervescent disintegrating agent, a large number of bubbles (carbon dioxide) will be produced rapidly, which will make the tablet disintegrate and melt rapidly, and the carbon dioxide produced during the disintegration of the tablet will partly be dissolved in drinking water, so that the drinking water will have a soda-like aesthetic feeling in the mouth. Sometimes the bubbles generated by the disintegration will also make the effervescent tablets in the water roll up and down, so that it disintegrates and melts.

Currently on the market there are VC effervescent tablets, ginkgo effervescent tablets on sale, a variety of flavors and varieties of effervescent tablets continue to be developed. There are already effervescent tablets containing tea (including tea extracts and active ingredients), fruits and vegetables, micronutrients and so on.

Effervescent solid drinks have developed quite rapidly in recent years, mainly because they have some advantages compared with traditional liquid drinks as follows:

① natural flavor, good instant solubility, wide range of applications, easy to drink;

② significant reduction in quality, volume significantly smaller, easy to carry;

③ simple packaging, easy transportation, water content of less than 5%, not only long shelf life, not easy to deteriorate, and small size, easy to carry and transportation.

④Easy to maintain hygiene;

⑤ Often added to effervescent tablet solid beverage there are many nutrient-rich substances, such as vitamins, amino acids, fruit juices, honey, etc., in the drink at the same time the human body gets the rich nutrients needed by the human body, which is beneficial to the human body’s physical development.

Due to the above advantages and its simple and mature production process, the sales volume of effervescent tablet solid beverage has been increasing dramatically for a long time, and the market prospect is relatively broad.

This part will be from the effervescent tablets main material granulation technology, effervescent tablets main material and auxiliary materials, processing equipment in three aspects, combined with the application of examples over the years, to show the current development of China’s effervescent tablets processing technology.

Effervescent tablet solid beverage granulation technology

1. Ordinary granulation method of effervescent tablets

Effervescent tablets of the main material preparation commonly used wet granulation technology, dry granulation technology, non-aqueous granulation technology, control of granulation water content technology, direct compression technology.

1.1 Wet granulation method

The acid or alkali are granulated and dried with water-containing binder, and mixed well before tabletting. This method avoids the contact of acid and alkali, prevents acid-base reaction during operation, and is favorable to the stability of the preparation. Its products have the advantages of beautiful appearance, good fluidity, stronger abrasion resistance, good compression molding, etc., and are most widely used in the pharmaceutical industry, food industry and other fields. However, it is not applicable to the granulation of special materials such as heat-sensitive, moisture-sensitive, extremely soluble and so on.

Effervescent tablets have higher requirements for the preparation environment, especially when using wet granulation, the relative humidity should not exceed 30%. For example: the preparation of pumpkin cornstarch effervescent tablets, pu-erh tea effervescent tablets prepared using wet granulation process, respectively, granulation and drying and sweeteners and other raw materials, mixing, compression of tablets and become.

1.2 Dry granulation method

Granulation is carried out by rolling or pressing method. The method requires less auxiliary materials, simple process, short cycle, small pollution, is conducive to improving particle stability, disintegration and dissolution; but should pay attention to the selection of adhesion and compressibility of better auxiliary materials. This method is mostly applied in the test, due to the high price of equipment, not many factory applications.

For example: the preparation of stevia effervescent tablets, stevia extract using dry granulation pressed into the oral preparation of traditional Chinese medicine, the preparation contains carbonates and organic acids, water can produce gas into effervescent.

1.3 Non-aqueous granulation method

The components of the prescription with non-aqueous liquid (such as isopropyl alcohol, anhydrous ethanol) granulation. This operation is simpler than the wet granulation, but easy to have binder residue, so it is also necessary to measure the amount of residue; in addition, the price of non-aqueous binder is slightly higher than the wet granulation. For example: the preparation of matcha effervescent tablets, VC effervescent tablets choose non-aqueous granulation, through this method of preparation of effervescent tablets, effervescent effect is good, the appearance of the integrity of the taste and smell good.

Control the water content of granulation: generally use the appropriate amount of citrate-hydrate instead of anhydrous, control the water content of the granules, when the mixture is heated, that is, the release of water of crystallization is easier to operate than the amount of water added to the granulation; wet particles immediately pressed tablets, and then tablets will be dried.

1.4 Direct tablet pressing method

The powder of the drug and the appropriate excipients were sieved and mixed, not after the granulation process, directly to the drug and excipient mixture for tabletting. This method of drug to have a certain fluidity, preferably with a certain crystal shape, to choose the appropriate excipients, and then the mixture of direct compression of tablets, can omit the step of granulation, can save time and energy, easy process, less process, suitable for the moisture and heat instability of the drug; but there is also a poor fluidity of the powder, the weight of the tablets varies greatly, and powder compression is easy to cause weaknesses of lobes and so on.

Combined with a variety of effervescent tablets prepared on the basis of practice, we found that the mainstream of several granulation processes, wet granulation helps to stabilize the preparation, but is not suitable for heat-sensitive, moisture-sensitive, extremely soluble and other special materials such as granulation, the requirements of the relative humidity should not be more than 30%; dry granulation is generally used for the production of pharmaceutical materials and laboratory operations; the preparation of matcha tea effervescent tablets, VC effervescent tablets are generally used in the non-aqueous granulation method, but non-aqueous granulation binder is not a good choice. However, the price of non-aqueous granulation binder is higher; direct compression method is suitable for drugs that are unstable to moisture and heat, such as blackberry effervescent tablets.

2. Novel Granulation Methods

2.1 Extended-release effervescent tablets

The active ingredients and excipients are made into granules, and water-insoluble and swellable acrylic polymers and water-soluble cellulose derivatives are encapsulated in the outer layer of the granules, which are then mixed with granules made from acids and bases and pressed into tablets. This method can control the release rate and thus achieve long-lasting effect.

2.2 Solid Dispersions Effervescent Tablets

Solid dispersion is a dispersion system in solid form formed by highly dispersing the drug in a solid carrier. The particle size of the drug in the carrier ranges from 0.001 to 0.100 mm. J. Li et al [11] prepared vitamin B complex effervescent tablets by solid dispersion method and proved that it disintegrated rapidly.

2.3 Multilayer effervescent tablets

This method can reduce the volume of effervescent tablets, reduce the amount of excipients and accelerate their disintegration in water. Zhang Lingling et al [12] developed 3-layer effervescent tablets of Ambroxol Hydrochloride, the results showed that the initial and long-term stability of this effervescent tablet was significantly better than that of ordinary effervescent tablets under the environment of high temperature, high humidity, and strong light irradiation.

2.4 Citrate hydrate compression method

Replacing anhydrous material with appropriate amount of citrate hydrate, which can control its water content, the mixture was heated to release the water of crystallization, and the particles were pressed and dried.

Effervescent Tablets Main Ingredients and Excipients

Effervescent tablets contain main and excipient ingredients, the excipients include disintegrants, granulating agents, sweeteners, flavors, fillers and so on. In foodstuffs, all of the above excipients must be of edible grade and characterized as soluble in water or soluble in water after compounding in order to make a clarified and transparent beverage after effervescence.

1.Disintegrant

Effervescent disintegrants have both an acid source and a base source, and their mechanism of action is to cause the base source therein to react with the acid source to produce carbon dioxide. Citric acid, malic acid, tartaric acid, adipic acid, fumaric acid, lactic acid, water-soluble amino acids and so on are the more commonly used acid sources.

Citric acid is currently the most widely used source of effervescent acid, its physical properties of colorless translucent crystals or white powder, with a good taste, easily soluble in water, and many other advantages, but because of its strong hygroscopicity, easy to cause up the tablets, viscous punch. Malic acid has better taste, but its hygroscopicity is also stronger, easy to sticky punch.

Citric acid is more acidic than tartaric acid, soluble in water, hygroscopicity is small, the disadvantage is that it is easy to react with many minerals and produce precipitation, affecting the view. Adipic acid does not absorb moisture, and its lubricating effect is better, but the reaction process with the alkali source is slow, and the reaction is not complete and there are residues. Fumaric acid has better lubrication and is not hygroscopic, but it is less acidic.

The more commonly used alkali sources include sodium carbonate, sodium bicarbonate, and potassium bicarbonate. In order to stabilize the effervescent tablets in the solid state and prevent the acid and base from reacting during preparation, a protective agent can be applied to the outside of the base source so that the effervescent tablets do not react with the acid source in the solid state.

In the preparation of effervescent tablets, the ratio of acid and alkali has a significant effect on their stability. In general, the amount of acid used exceeds its theoretical amount, which can improve the taste of the effervescent tablets as well as increase their stability.

2. Granulating agent

Granulating agent includes binder and lubricant. Commonly used binder includes starch slurry, PVP ethanol solution, hydroxypropyl methylcellulose aqueous solution, syrup and so on. Because PVP ethanol solution is prone to moisture absorption, a copolymer of polyvinylpyrrolidone and polyvinyl acetate is generally used as the binder.

The lubricant can solve the problems of tablet rise and sticky punch in the tablet pressing process, and should have good lubricity and water solubility. Commonly used lubricants include polyethylene glycol 6000, L-leucine, sodium (potassium) stearyl fumarate, sodium (magnesium) lauryl sulfate, etc. L-leucine has better lubricating effect, but it is more expensive.

Polyethylene glycol 6000 lubricant in the tabletting process, because of its low melting point, punch friction heating will make it soften, sticky punch, thus affecting the production efficiency, so in the production of the dosage of not more than 5% of the total weight to prevent excessive increase in the viscosity of the punch and need to be crushed through the 160 mesh sieve after use.

Lubrication effect is also related to the particle size of the lubricant, sodium benzoate and L-leucine after spray drying can significantly improve the lubrication effect. In order to achieve better lubrication effect, can be several kinds of lubricants in accordance with a certain proportion of mixing. 3.

3. Sweeteners and flavoring agents

Sweeteners include sodium cyclohexanesulfamate, sugar, saccharin sodium, saccharin calcium, licorice sweet, dihydrochalcone, asparagine and so on. Sweeteners can be classified into 2 types: natural and artificial. Generally, the amount of natural sweeteners is less than 5%, while the amount of artificial sweeteners is less than 1%. Flavoring agents include menthol, peppermint oil, artificial vanilla, cinnamon, and various fruit flavors. The general dosage ratio is 0.5% to 3.0%.

4. Flavors and colors

Flavors include sweet orange, lemon, pineapple and so on. In food, effervescent tablets can also be added to a small amount of coloring, the type and amount added should be in line with national food additive standards.

5. Filling agents

Filling agents include dextrin, starch, lactose, glucose, mannitol and so on. Among them, starch is neither soluble in water nor in ethanol, and it is more stable in air, so it can absorb water without deliquescence. Dextrin is soluble in hot water and dissolves slowly in cold water, and is insoluble in ethanol. Lactose is often chosen as filler for effervescent tablets, which is soluble in water and more stable in air.

Processing equipment for effervescent tablets

The production process of effervescent tablets, such as crushing, mixing, drying, pressing and so on, needs specialized equipment to cooperate with the production, so as to make the effervescent tablets of qualified quality and efficient production.

Equipment settings must be decided according to the process route, the main production involved in the crushing equipment, such as sieve mill; combined equipment, such as single-propeller tank mixer; molding equipment, such as swing granule molding machine; drying equipment, generally using superheated steam drying method, dry hot air boiling method, drying oven, etc.; in the selection of homogenizer, the use of high-pressure homogenizer or colloidal mill; sugar pot is used to melt all kinds of sugar in the protein-based effervescent tablets. Sugar pot is used to melt all kinds of sugar in protein effervescent tablets.

Application in food industry

At present, the main products of effervescent solid drinks on the market are VC effervescent tablets, including a variety of fruit-flavored VC effervescent tablets. In addition, micronutrient supplements such as iron tablets are also common. With more and more in-depth research on effervescent tablet solid beverage, its product varieties are increasing. According to the different raw material composition of effervescent tablets, the existing several edible effervescent tablets are divided into four categories for brief description:

1. Tea effervescent tablets

Tea effervescent tablets – effervescent tablets containing tea and its active ingredients in tea, such as tea extracts, catechins, tea polyphenols, tea polysaccharides, instant tea and other components of the formula of the effervescent tablets. Pu’er tea, honeysuckle tea, matcha tea and barley black tea effervescent tablet solid beverages are used as examples to understand the specific process of making tea effervescent tablets.

1.1 Pu-erh Tea Effervescent Tablets

Pu-erh tea effervescent tablets are made by grinding tea powder, filler, effervescent agent and binder through 0.11mm sieve, wetting and mixing the material with anhydrous ethanol, granulation with 1.21mm sieve, and then vacuum drying in vacuum drying oven at 45℃ for 30min, and then whole granules with 1.21mm and 0.894mm sieve, while discarding the part below 0.894mm and above 1.21mm. The resulting particles were weighed, added with lubricant (0.11mm sieve) and mixed well, and then sent to a tablet press to press the tablets, and the effervescent tablets were made by sealing and preserving the tablets.

Due to the acid-base two granulation method of pu-erh tea effervescent tablets are easy to appear flower tablets, and in the disintegration of water will appear in the tea powder cohesion caused by the insoluble small particles, so this study adopts the one-phase mixing wet granulation.

1.2 Honeysuckle tea effervescent tablets

The preparation process of honeysuckle tea effervescent tablets is to prepare honeysuckle extract powder first:

First take 6kg honeysuckle, add water to soak twice (each time with 10 times water, extraction 0.5h), combined extraction twice (each time with 10 times water, extraction 0.5h), combined extract, 60 ℃ concentrated to thick paste, at 60 ℃ under the condition of drying under pressure crushed to get the paste powder 1257g;

Then according to the preparation of effervescent tablets to take the proportion of 40% of the weight of the entire tablet honeysuckle extract powder, add 15% sodium bicarbonate and citric acid mass ratio of 1.3:1 composed of disintegrating agent, diluent for 32% lactose, mixing, with 1% PVP-K30 anhydrous ethanol solution granulation, through 20 mesh sieve, at (45 ± 5) ℃ under the conditions of decompression drying for 4h, the whole granule;

Add 1% PEG6000 as lubricant and 12% by PEG6000 wrapped in sodium bicarbonate and citric acid mass ratio of 1.3:1 disintegrating agent, that is, the use of non-aqueous method of granulation to manufacture effervescent tablets, the finished product after pressing.

1.3 Matcha effervescent tablets

The preparation process of matcha effervescent tablets adopts the formula of matcha 4.0%, meringue 3.6%, sugar 17.8%, citric acid 35.6%, sodium bicarbonate 31.1%, maltodextrin 6.7%.

At the same time add appropriate amount of suspending agent and 4%~6% powder flavor, binder is 1% PVP anhydrous ethanol solution, lubricant is 2%~3% PEG6000 or soluble starch. The granulation process was selected as acid-base mixed non-aqueous granulation method, and the matcha tea effervescent tablets prepared by this method had a good effervescence effect, sweet and sour taste, and tea aroma.

1.4 Barley black tea effervescent tablets

The preparation process of the new barley black tea effervescent tablet solid beverage uses instant black tea powder and instant barley powder as the main raw materials, and aspartame and other auxiliary materials, and adopts the wet granulation method to manufacture effervescent tablets, and takes the disintegration time, taste and so on as the indexes of investigation, and selects the ratio of the main and auxiliary materials through the one-way test and the orthogonal test.

The optimal formulation of barley black tea effervescent tablets was 2.0% of instant black tea powder, 18.1% of instant barley powder, 36.7% of sodium bicarbonate, 9.2% of aspartame, 60001.0% of polyethylene glycol and 33.0% of citric acid. The average disintegration time of the effervescent tablets is 3.6min, and the beverage obtained after dissolving in water is yellowish brown, sweet and sour, rich in the aroma of barley and black tea.

The majority of tea-containing effervescent tablets are multifunctional effervescent tablets with anti-fatigue, anti-aging and other health functions. The preparation of tea-containing effervescent tablets generally adopts non-aqueous granulation method and wet granulation method. Among them, non-aqueous granulation method accounts for the majority, the preparation process of this method is simple, can retain part of the beneficial substances, more suitable for the preparation of tea-containing effervescent tablets.

2. Fruit and vegetable effervescent tablets

Fruit and vegetable effervescent tablets is to fruit or vegetable as the main material, fruit and vegetable active ingredients formulated effervescent tablet solid beverage, the current fruit and vegetable effervescent tablets for the study of a lot of documents, which is more on the extraction of fruits and vegetables in the human body is beneficial to the study of the active ingredients, such as: pumpkin cornstarch effervescent tablets, blueberry effervescent tablets solid beverage, fruit and plum children’s health care effervescent rinse, melon effervescent tablets, hawthorn effervescent tablets, and so on. Now to cool melon effervescent tablets, blackberry effervescent tablets, blueberry effervescent tablets and so on one by one to introduce its preparation process.

2.1 Cool melon effervescent tablets

Cool melon effervescent tablets to acid and alkali respectively granulation method for manufacturing effervescent tablets, its main preparation process is to filler and cool melon powder is divided into two parts, the other with sodium bicarbonate mixed with binder and deionized water for making soft materials, drying, crushing and sieving steps.

One part is mixed with citric acid plus binder and deionized water for soft material making, drying, crushing and sieving. The resulting two powders were then mixed proportionally, added to the crushed and sieved lubricant mix, and pressed into tablets.

At the same time, the dried cool melon was crushed and sieved through 80 mesh to obtain the raw material. Drying temperature are 50 ℃, drying time is 4h, in the tablet pressure less than 20Pa conditions to prepare cool melon effervescent tablets.

2.2 Blackberry effervescent tablets

Blackberry effervescent tablets were prepared by direct powder compression method, and its optimal formula was as follows: blackberry powder (containing maltodextrin 48%) 41%, sodium carbonate 24%, citric acid 35%, aspartame 0.2%. The process is that the other materials are first crushed, then sieved, then blackberry powder is added for mixing, and finally the tablets are pressed and packed.

The experimental results show that the blackberry effervescent tablets obtained by this method are not deformed in appearance, not easy to absorb moisture, the disintegration time limit is 40s, the sweet and sour is moderate, and there is no obvious precipitation after disintegration.

2.3 Blueberry effervescent tablets

Blueberry effervescent tablets are prepared by wet granulation (relative humidity should be ≤ 30%) for the preparation of effervescent tablets, and after repeated tests, the results show that the best scientific composition of blueberry effervescent tablets (weight percentage), 15% of blueberry fresh fruit juice concentrated and dried extract at room temperature freshness and low temperature, 21% of β-cyclodextrin, 5% of vitamin C, 28% of sodium bicarbonate, 26% of citric acid, 0.1% of magnesium stearate, and 5% of sucrose.

The effervescent tablets have rapid and uniform distribution in water, high bioavailability, easy absorption of active ingredients, comfortable taste, crispy texture, convenient consumption, both solid and liquid preparations, and have a broad market prospect in the food industry.

2.4 Other fruit and vegetable effervescent tablets

Pumpkin cornstarch effervescent tablets are made by wet granulation process, acid and alkali granulation and drying respectively, mixed with sweeteners and raw materials, and pressed into tablets. Fruit plum children’s health care effervescent punch preparation process is: in the fruit plum, hawthorn extract concentrate add sugar (drying and crushing through 60 mesh sieve), zinc chloride, flavor, lysine and other mixing, and then granulation, granulation, these mixtures after drying, crushing, and then add citric acid, sodium bicarbonate and extracts mixing, through the 80 mesh sieve, sterilized, and finally packaged finished product.

Hawthorn effervescent tablet is hawthorn powder obtained from hawthorn by softening, pulping, microfine, homogenization, enzymolysis, spray drying, matched with citric acid, proteins sugar, sodium bicarbonate and other raw materials, and adopted dry granulation preparation process.

Fruit and vegetable effervescent tablets are taken from daily life fruits and vegetables, through in-depth research of raw materials, coupled with mature processing technology and scientific formula, fruit and vegetable effervescent tablets make the release of nutrients in raw materials be effectively improved. The preparation process of fruit and vegetable effervescent tablets generally adopts wet granulation; fruit and vegetable extracts are selected, mixed with acid and alkaline granulation raw materials and auxiliary materials, and pressed into tablets.

3. Vitamin effervescent tablets

Vitamin effervescent tablets have been available at home and abroad in recent years, with a single ingredient or a variety of vitamins and different fruit-flavored series of products, is a source of vitamin supplementation. The production process has been very mature, and the majority of effervescent tablets on the market are VC effervescent tablets, of which there are also multivitamin effervescent tablets.

Vitamin effervescent tablets generally use non-aqueous granulation method to obtain good stability, short disintegration time, simple process, quality control products.

4. Trace element supplement effervescent tablets

Trace element supplement effervescent tablets such as calcium supplements effervescent tablets, calcium citrate-malate (CCM) effervescent tablets and nutritional effervescent milk tablets. Micronutrient supplements have a variety of benefits and functions for the human body, such as the ability to prevent cancer, reduce anxiety and perceptual stress, and reduce the incidence of cataracts. Therefore, trace element supplements are becoming increasingly popular.

Calcium citrate-malate (CCM) effervescent tablets are prepared as follows: CCM is crushed through a 100-mesh sieve, VC, stevia, baking soda are added, put into a mixer for mixing, polyvinylpyrrolidone is added for mixing, 12-mesh granulation is carried out, and the wet granules are ventilated and dried under the condition of about 50°C and passed through a 14-mesh sieve for the whole granule. Then add PEG6000 for mixing, fully mixed, put into the tablet press in the tablet molding, drying at 60 ℃ under the condition of 2h, sterilization, packaging, that is, CCM effervescent tablets.

The development direction and prospect of effervescent tablet solid beverage

The development of effervescent tablet solid beverage will certainly be centered on the traditional consumption habits of the public, and broaden the sales market of non-traditional solid beverages.

The promotion of effervescent tablets in China should make full use of and develop the advantages of rich material resources in China, and actively develop the nutritious, functional and special effervescent tablet solid beverages such as plant protein, fruit and vegetable juices, milk protein, instant tea, and so on. Combined with China’s rich agricultural resources, traditional consumer demand and new effervescent tablets featuring products of the region of origin as a hot spot for research and development.

As effervescent tablets can be added with flavoring agents, sweeteners, coloring agents, and excipients in addition to the main agent and effervescent agent in the process of production, it is possible to improve the flavor of food and develop a series of flavored effervescent food products for food. As effervescent tablets have a special disintegrating agent – effervescent disintegrating agent, can be quickly disintegrated in cold water, which is conducive to absorption, easy to carry and take, good color and flavor, ready to drink, especially catering to the young people who love the advantages of the new, strange, special, in the field of children and adolescents have obvious advantages.