Due to rapid economic development and increasing market demand after the 1980s, research on the production of modified starch and starch derivatives developed very quickly in China.
This post describes the present situation and the development potential of modified starch, starch sweeteners, saccharide alcohol, degradable starch plastics, oligo-saccharides, and lactic acid made from cassava starch in China, including the production and use of the most popular products.
Progress made, and future planning for developing these products will also be discussed.
Industrial Development of Starch in China
In recent years the production and application of starch, modified starch, and starch derivatives developed rapidly, in line with the overall development of the Chinese economy (Table 1).
The development of starch derivatives depends mainly on the rapid growth of the starch industry.
From 1989 to 1998, the total production of Chinese starch increased about 2.7 times, from 1.12 to nearly 3 million tonnes. The scale of the starch factories has also grown considerably while their numbers have decreased (Table 2).
Production of cassava starch showed a similar trend. Guangxi is the largest cassava-producing province in China, with cassava production there accounting for more than 50% of total national production. The cassava planted area, total fresh cassava root production, and starch output are shown in Table 3.
As indicated in Table 3, from 1989 to 1998, the cassava planted area increased by 24%, the yield by 72%, new root production by 113%, and cassava starch production by 170%.
Modified Starch and its Applications in China
The present situation of Chinese modified starch
Recently, the modified starch industry in China has developed rapidly (see Table 1); modified starch production in 1998 was 7.5 times greater than in 1989. This has been the result of the following factors:
- Production of starch in China has increased rapidly, so the starch factories had to search for new markets.
- The demand for modified starch from various industries increased very quickly.
- With the opening up and reform of the Chinese scientific system, a more creative technological development framework was established, resulting in new progress in research, development, and utilization of modified starch.
- As new foreign technologies were introduced, demand for modified starch increased.
- New enterprises have high-quality requirements, so demand for modified starch with high-added value increased.
| Starch | Modified starch | Crystal glucose | Liquid Glucose | |
| 1989 | 1,117 | 21.6 | 109.4 | 144.5 |
| 1992 | 1,200 | 34.8 | 134.0 | 70.8 |
| 1993 | 1,600 | 54.0 | 149.0 | 85.0 |
| 1994 | 2,470 | 59.8 | 198.8 | 138.3 |
| 1995 | 2,600 | 80.9 | 220.9 | 108.1 |
| 1996 | 2,645 | 73.4 | 196.4 | 168.6 |
| 1997 | 2,589 | 91.3 | 145.8 | 170.1 |
| 1998 | 2,978 | 162.0 | 157.4 | 256.0 |
| % increase since 1989 | 167 | 650 | 44 | 77 |
| 1989 | 1993 | 1998 | |
| Number of starch factories | 388 | 243 | 157 |
| Total annual capacity (million tonnes) | 1,167 | 1,520 | 2,978 |
| Average power (t/year) | 2900 | 6255 | |
| Number of factories of >100,000 t/year capacity | 14 | 37 | 67 |
| Number of factories of >200,000 t/year capacity | 0 | 0 | 2 |
| Year | Planted area (‘000 ha) | Yield (t/ha) | Fresh root production (‘000 t) | Starch production (‘000 t) |
| 1989 | 210.6 | 8.24 | 1,734.9 | |
| 1990 | 219.3 | 8.82 | 1,934.5 | 122.5 |
| 1991 | 221.5 | 9.00 | 1,993.8 | 168.2 |
| 1992 | 213.3 | 9.95 | 2,121.4 | 191.0 |
| 1993 | 219.7 | 11.43 | 2,511.7 | 230.0 |
| 1994 | 229.6 | 12.15 | 2,789.3 | 258.2 |
| 1995 | 272.9 | 13.68 | 3,733.5 | 273.0 |
| 1996 | 288.9 | 13.41 | 3,873.7 | 321.2 |
| 1997 | 273.3 | 14.22 | 3,886.1 | 385.0 |
| 1998 | 260.5 | 14.21 | 3,701.6 | 330.3 |
Types of Chinese modified starch
Modified starch can be divided into three main groups according to the modification process utilized.
These three groups are further subdivided according to processes and products:
- Physically modified starch: Pyrodextrin (white dextrin, yellow dextrin, soluble dextrin), Pregelatinized starch (α-starch), Fractionated starch (amylose, amylopectin).
- Chemically modified starch: oxidized starch, esterified starch, etherified starch, graft co-polymerized starch.
- Enzymatically modified starch: Enzyme degradation starch (maltodextrin, cyclodextrin).
Current and future applications of modified starch
China modified starch has an excellent development prospect (Table 5). The paper and cardboard industry of China in 1996 consumed 300 thousand tonnes.
Moreover, for the papermaking industry in China, unlike in most other countries, wood pulp is a minor raw material, while the primary raw materials are straw pulp and bagasse. The straw pulp fiber is shorter, and of lower strength, so it needs more modified starch.
The proportion of modified starch used in the American papermaking industry is 2%.
It is estimated that the consumption of modified starch in China’s papermaking industry will be above 700,000 tonnes.
Other industries, such as textile, food, medicine, and materials used for construction and environmental protection, consume a lot of modified starch.
Advantages and development prospects of modified cassava starch
Cassava starch is characterized by low pasting temperature, high viscosity, and easy enzymatic hydrolysis. Pregelatinized starch and cationic starch made from cassava starch have particular quality advantages.
| Product | Production process | Application |
| Yellow dextrin | Heat for roasting | Casting, construction materials |
| White dextrin | Heat for roasting | Binding agents in medicines |
| Pregelatinized starch | Dried and milled by drum | Feed, casting, construction materials |
| Oxidized starch | Oxidized by the oxidizing agent | Binding agent for cardboard, textile, food |
| Acid-hydrolyzed starch | Hydrolyzed by acid | Food, sizing for fabrics, paper making |
| Starch acetate | Esterification by acetic acid | Papermaking, textile, casting, food, snack food |
| Cationic starch | Etherification by trimethyl amine | Paper pulp additive coating |
| Complex modified starch | Paper pulp additive coating | |
| Carboxymethyl starch | Etherification by chloroacetic acid | Lubricant for oil drilling medicine, construction materials |
| Hydroxy-propyl starch | Food, candy | |
| Cross-linked starch | Food, medicine, textile, and chemical industry | |
| Graft co-polymerized starch | Graft co-polymerized by acrylonitrile | High water-absorbent materials, such as disposable diapers, female napkins, textile sizing material |
| Application of modified starch products | Current production | Current domestic market volume | Expected future domestic market volume |
| Textile | 50 | 100 | 120 |
| Paper | 40 | 350 | 700 |
| Food | 3 | 200 | 400 |
| Medicine | 10 | 20 | 40 |
| Agriculture | X | 100 | 200 |
| Casting | X | 37 | 75 |
| Animal feed | X | 100 | 200 |
| Construction materials | X | 50 | 80 |
| Oil drilling | X | 30 | 50 |
| Fine chemicals | X | 10 | 30 |
| Total | 103 | 997 | 1895 |
Pregelatinized starch: About 10,000 tonnes of pregelatinized starch are produced annually in Guangxi.
The quality of pregelatinized starch from cassava starch is better than that from maize starch, resulting in good market demand and a 10% higher price than that made from maize starch.
Cationic starch: Approximately 10,000 tonnes of tri-methyl amine cationic starch are produced annually in Guangxi.
The cationic starch made from cassava has a low viscosity and a high degree of substitution, making it especially suitable for the sizing and coating high-speed papermaking machines.
Recently, the Guangxi Nanning Cassava Technical Development Center, in cooperation with the Mingyang Starch Factory, succeeded in developing a solid process for cationic starch production.
The degree of substitution of the product is higher than that of the original wet process, there is no pollution, and the production cost is 20% lower, giving it a solid competitive advantage
Besides, Guangxi also produces oxidized starch, starch acetate, amphoteric starch, yellow dextrin, starch phosphate, etc.
Starch-based Sweeteners
China has a 3000 years history of producing sweeteners made from starch.
Ancient China was the first to invent sugar production from plants’ raw materials, especially maltose from rice starch.
Starch-based sweetener production started with the manufacture of malt syrup.
At present, China produces several kinds of starch-based sweeteners, as indicated below:
Glucose syrup
After the starch is hydrolyzed by enzymes or acid, malt syrup is obtained and divided into high-DE, medium-DE, and low-DE syrups according to their different DE values, as shown in Table 6.
Maltose
Table 7 shows several types of maltose syrups produced in China.
Fresh wheat bran contains a considerable amount of β-glucosidase, an enzyme that can decompose starch molecules to produce maltose; this technology is used for creating maltose syrup in China.
Glucose
Table 8 lists the principal types, characteristics, and uses of glucose produced in China. So far, China has mainly four production technologies for glucose, as indicated in Table 9.
Conversion and isomerization sweeteners
In the Chinese market, we have four types of fructose-glucose products, as shown in Table 10.
| Product | DE value | Degree of hydrolysis | Main ingredients | Product form | Usage |
| Malt dextrin | 10-15 | Low | low molecule dextrin malt polymaltose iso-maltose glucose | powder liquid | milk powder, substitute solid drink, oral soluble dosage food |
| Malt syrup | 25-35 | Medium | maltose glucose maltotriose | liquid 70-80o Bx | confectionery |
| Glucose syrup | 42-55 | Medium | glucose maltose | liquid 70-84o Bx | confectionery |
| Liquid Glucose | 75-94 | High | glucose maltose malt poly-saccharide salt | liquid 70o Bx | syrup, food, antifreeze, sorbitol |
| Mother liquid of glucose | 75-80 | High | liquid 60o Bx | caramel-coloring, antifreeze, sorbitol |
| Product | Maltose content (%) | Characteristics | Usage |
| Maltose | <50 | liquid, sweet, sensitive to moisture | daily food |
| High-maltose syrup | 50-75 | liquid, sweet, sensitive to moisture | special food |
| Super-high-maltose syrup | 75-95 | liquid, sweet | special food |
| Crystal maltose | 90 | strong water absorption | special food |
| Crystal anhydrous maltose | 90 | highly soluble | dehydrating agent |
| High purity maltose | 99 | high purity | injection solution |
| Product | Specification | Price (Yuan/t) | Usage | 1996 Production (‘000 t) |
| Medical anhydrous glucose | China Pharmacopoeia 1995 | 5200 | injectable solution | 20 |
| Medical glucose | China Pharmacopoeia 1995 | 4500 | injectable solution | 120 |
| Oral glucose | China Pharmacopoeia 1995 | 4200 | food; sorbitol for the production of Vitamin C | 50 |
| Industrial glucose | Industrial grade | 3900 | general industrial use of sorbitol production | 40 |
| Industrial total powder sugar | DE 90 | 3000 | industrial use | 20 |
| Production process | Mixing | Acid liquification | Enzymatic liquefaction | Acid saccharification | Enzymatic saccharification | Decoloration and filtering | Concentration |
| Acid process | ✓ | ✓ | ✓ | ✓ | ✓ | ||
| Enzymatic process | ✓ | ✓ | ✓ | ✓ | ✓ | ||
| Acid-enzymatic process | ✓ | ✓ | ✓ | ✓ | ✓ | ||
| Enzymatic acid process | ✓ | ✓ | ✓ | ✓ | ✓ |
| Product name | Viscosity | Fructose content (%) | Sweetness compared to sucrose | Usage |
| Fructose-glucose syrup | 70 Bx | 42 | 0.9 | food |
| High-fructose syrup | 75 Bx | 55 | 1.1 | soft drinks |
| High-purity fructose syrup | 80 Bx | 90 | 1.6 | special drinks |
| Crystalline Fructose | solid | >98 | 1.8 | special food/drinks |
Oligo-saccharides
Oligo-iso-maltose
The enzyme transglucosidase (TG) interacts with maltose and glucose, resulting in an inversion reaction, which produces iso-maltose, panose, iso-malto-triose, etc.
Oligo-iso-maltose can not be digested and fermented by yeast, but it can be used by Bifidobacterium iridium to enhance its reproduction; this is good for the intestinal bacterial colonies and elevates the proportion of favorable settlements resulting in a healthy functioning of the digestive system.
This kind of oligo-iso-maltose has been produced in the starch industry; the procedure is as follows:
1) liquify starch milk with the use of α-amylase;
2) saccharify with the combination of β-amylase and glucose group invertase; β-amylase yields maltose, invertase yields iso-maltose and panose through the linking of α-1,6 link yield glucose and maltose.
3) refine and concentrate to 75%. A colorless, transparent solution is obtained, which contains the following substances (dry weight basis): 16.9% iso-maltose, 12.5% panose, 3.4% iso-malto-triose, 6.7% maltose, and 40.5% glucose. The content of iso- 560 maltose can be elevated to as high as 85% with resin chromatography while glucose is removed.
Oligo-fructose
Oligo-fructose is one of the edible enhancement and function foods. Because the bio-reactions of oligo-fructose are almost the same as short-link soluble cellulose, it can be used as a source of edible cellulose.
In China, oligo-fructose is now produced on an industrial scale and marketed. The first production line of 3000 t/year was set up in Yunnan province.
Researchers of Guangxi University used the immobile enzyme to produce oligo-fructose successfully; a 1000 t/year production line has been built.
Besides oligo-iso-maltose and oligo-fructose, new oligo-saccharides, such as oligo-saccharide, oligo-mannose, etc., have also been researched.
Hydrogenated Sweeteners
Sorbitol
Sorbitol is the primary raw material for the production of vitamin C. It is also a favored sweetener for diabetic patients and can function as an effective moisture absorbent; it absorbs water strongly, so it has been used widely in the production of toothpaste and cosmetics.
The present diversity and characteristics of various sorbitol-based products in China are shown in Table 11.
Mannitol
Mannitol is the only polyol that is solid under normal conditions. It is a favored medicine for diuretic and dehydration problems.
Mannitol is one of the essential medicines in all hospitals. In industry, mannitol is the primary raw material for producing polyester and polyether, crucial raw materials for making foamed plastic.
Currently, mannitol in China’s market is mainly derived from seaweed, with an annual production capacity of 8,000 tonnes. The cost is high, and the production process is out of date.
In recent years China has developed a new technology, which uses sucrose or glucose to manufacture mannitol, and has begun industrial production.
Hydrolysis of sucrose can yield the inversion sugars fructose and glucose, producing 25% mannitol and 75% sorbitol, respectively, when hydrogenated.
After special isomerization, part of the glucose can be inverted to mannose and fructose, yielding 42% mannitol and 58% sorbitol when hydrogenated.
Recently, research on the adoption of a simulated fluid bed to separate mannitol
and sorbitol has been successful.
Maltol
Maltol is a new type of dietary supplement produced by hydrogenating maltose. Maltol is a transparent, colorless, or lightly yellow solution.
Maltol is non-fermentable, so it may be used to prevent dental decay; it is low in calories, so it may be used to avoid obesity; it has good flavor with a sweetness of 90% of that of sucrose; it has a high viscosity and may be used as a thickener; moreover, it has high heat and acid resistance, good moisture retention, so may be used for moisture adjustment.
561 it hardly decomposes by insulin, so it can be used as food for people with diabetes. About 10,000 tonnes are produced annually in China, mainly using cassava starch.
| Characteristic | vitamin C production | detergent and cosmetics production | toothpaste production | Injectable Sorbitol l | Hard crystal sorbitol | Solid sorbitol | Icy sorbitol |
| Appearance | colorless and transparent solution | colorless and transparent solution | colorless and transparent solution | white powder | white hard granules | white soft granules | icy |
| Degree of substitution | 45-51 | 67-73 | 69-71 | 99.5 | 99.5 | 99.0 | 98.0 |
| Specific weight(gm/ml) | 1.228 | 1.280-1.316 | >1.285 | ||||
| Refractive index | 1.42 | >1.460 | 1.459-1.461 | ||||
| Reducing sugar (%) | >0.2 | 0.63 | >0.5 | 0.2 | 0.3 | 0.2 | 0.2 |
| Main usage | raw material for vitamin C | food, cosmetics, detergents | toothpaste | medical injection solution | food gum | chemicals and food | chemicals and food |
| Relative price | 1.1 | 1.0 | 1.0 | 3.5 | 2.8 | 1.6 | 1.3 |
Organic Acids
Besides citric acid and acetic acid, two kinds of organic acids using starch as the raw material have been developed successfully.
Lactic acid
Lactic acid is an essential organic acid; it can be used in the production of beer for adjustment of the pH of the malt, in the pharmaceutical industries, and the production of cosmetics, fine chemicals, tobacco, food, and silk.
Stearoyl lactate sodium and calcium salts are the most critical lactate salts, a general food additive used worldwide.
Monoglyceride lactate ester is an emulsifier suitable for producing biscuits, meats, milk products, fruit jams, and pectin.
In recent years, researchers have developed L-lactic acid, i.e., poly-lactic acid, an ideal fully-degradable plastic material, and easier to produce industrially.
Therefore, research on lactic acid in China has developed very fast. Presently, a 10,000 t/year L-lactic acid production line is under construction.
Itaconic acid
Itaconic acid and its esters are excellent additives and raw materials for manufacturing synthetic resins, plastic, rubber, ion-exchange resins, surfactants, anti-rust agents, etc.
Yunnan and Hubei provinces have produced the enzyme for itaconic acid. These factories succeeded in making itaconic acid from native cassava starch. So far, China has produced more than 5,000 tonnes of itaconic acid.