Sugars made from starch-containing grains, potatoes, etc., made by acid method, enzyme method, or enzyme method, including maltose, glucose, fructose syrup, etc., are collectively referred to as starch sugar. Food with starch and sugar includes sweet potatoes, potatoes, yams, taro, corn, cassava, wheat, rice and related products, etc. Starch sugar has a long history in China. Starch sugar was mentioned in "Qi Min Yao Shu" for more than 500 AD, and the method of making sugar with rice was described in detail.
Liquid glucose is a mixed syrup composed of glucose, maltose, and malt oligosaccharides obtained by controlling the proper hydrolysis of starch. Both glucose and maltose are sugars with strong reducing ability. The glucose value (dextrose equivalent) commonly used in the starch sugar industry is referred to as the DE value (all reducing sugars in the saccharification solution are calculated as glucose, and the percentage of dry matter is called glucose value) to indicate the degree of starch hydrolysis. Liquid glucose can be divided into three categories: high, medium, and low according to the degree of conversion. Liquid glucose with different DE values has certain differences in performance, so starch sugars with different degrees of hydrolysis can be selected for different uses.
Glucose is a product of starch completely hydrolyzed by acid or enzyme. Due to different production processes, the purity of the resulting glucose product is also different. This type of starch sugar can be generally divided into two types of crystalline glucose and whole sugar, of which glucose accounts for 95% to 97% of dry matter. The rest is a small number of oligosaccharides left due to incomplete hydrolysis.
If the refined glucose solution has flowed through the immobilized glucose isomerase column, a part of the glucose undergoes an isomerization reaction and is converted into its isomer fructose to obtain a syrup composed mainly of fructose and glucose. This kind of starch sugar is refined by activated carbon and ion exchange resin and concentrated to obtain colorless and transparent fructose syrup products. The mass fraction of this starch sugar is 71%, the sugar group is fructose 42% (dry basis), glucose 53%, oligosaccharide 5%. This is the international production of fructose syrup products in mass production in the late 1960s. The Sweetness of fructose syrup is equal to sucrose, but the flavor is better, known as the first generation fructose syrup product.
A starch syrup made from starch as raw material and hydrolyzed by enzyme or acid-binding method. Compared with liquid glucose, the content of this starch sugar in maltose syrup is lower (generally less than 10%). The content of maltose is high (generally 40% to 90%). According to different manufacturing methods, maltose content can be called caramel, high maltose syrup, ultra-high maltose syrup, etc. The sugar composition of this starch sugar is mainly maltose, dextrin, and oligosaccharides.
The metabolism of fructose syrup and high maltose syrup is not controlled by insulin, blood sugar will not rise, and the osmotic pressure is only half of the body's blood glucose metabolism. The starch sugar is decomposed and used by oral microorganisms and will not cause dental caries. Starch sugar like maltose can also be used as a wetting regulator for toothpaste, medical ointment, capsules, etc.
In the field of bioengineering technology, the protease activity can be stabilized by adding ultra-high maltose syrup. The shelf life of β-galactosidase is extended, the yield of kasugamycin has been improved, and it is also a necessary substance for diphtheria vaccine activity improvement No other alternatives.
Through the action of glucoside invertase maltose, oligomeric isomaltose containing non-fermentable oligosaccharides such as maltose, panose, and isomaltose can be prepared. Such polysaccharides are not digested and absorbed by the human body, but can be absorbed by the bifido Bacillus use and promote its proliferation; inhibit the growth of harmful intestinal bacteria, reduce spoilage products, etc .; improve human immunity. Generally speaking, the starch sugar can be used in industries such as pharmaceuticals, health products, and winemaking.
Different starch sugar products have differences in many properties, such as sweetness, viscosity, tackiness, thickening, moisture absorption, and moisture retention, osmotic pressure and food preservation, color stability, cooking, fermentation, reducibility, prevention of sucrose crystallinity, foam stability, etc. These properties are closely related to the application of starch sugar. Different uses require different types of starch sugar products. The following briefly describes the relevant characteristics of starch sugar.
Sweetness is an important property of sugar, but there are many factors that affect sweetness, especially concentration. The increase in concentration increases the sweetness, but there is a difference between the different levels of sugar. The degree of sweetness of the glucose solution with the concentration increase is greater than that of sucrose. At a lower concentration, the sweetness of glucose is lower than that of sucrose, but with the increase of concentration reduced, when the content reaches 40% or more, the sweetness of the two is equal (Table 6-1). The sweetness of starch sugar syrup increases with the degree of conversion. In addition, the mixing of different starch sugars has the effect of mutual improvement. Below are the sweetness of several sugars.
High fructose syrup（42Tyep）
Starch syrup(DE value 42)
Starch syrup（DE value 70）
The solubility of various sugars is different, fructose is the highest, followed by sucrose and glucose. The solubility of glucose is low, the concentration is about 50% at room temperature, and glucose concentration will be precipitated if the concentration is too high. In order to prevent the precipitation of crystals, industrial storage of glucose solution needs to control the glucose content below 42% (dry matter), the sugar composition of high conversion syrup to maintain glucose 35% to 40%, maltose 35% to 40%, fructose syrup (conversion rate 42%) quality score is generally 71%
Sucrose is easy to crystallize and the crystal can grow very large. Glucose is also easy to crystallize, but the crystals are fine. Fructose is difficult to crystallize. Starch syrup is a mixture of glucose, oligosaccharides, and dextrin. It cannot crystallize and prevents sucrose from crystallizing. This crystalline nature of sugar is related to its application. For example, in the manufacture of hard confectionery, sucrose is used alone and boiled to less than 1.5% moisture. After cooling, the sucrose crystallizes and cracks, and a tough and transparent product cannot be obtained. If a part of starch syrup is added, it can prevent sucrose from crystallizing and prevent sand from returning during storage. The dextrin in starch syrup can also increase the toughness, strength, and viscosity of the candy, making the candy not easy to break. In addition, the sweetness of starch syrup is more Low, has the effect of diluting the sweetness of sucrose, making the product sweet and mild.
Hygroscopicity and moisture retention
Different types of foods have different requirements for sugar hygroscopicity and moisture retention. For example, hard candy needs to have low hygroscopicity to avoid dissolution due to moisture absorption in wet weather, so it is better to use sucrose, low conversion, or medium conversion syrup. Invert sugar and fructose syrup contain highly hygroscopic fructose and should not be used. However, soft candy needs to maintain a certain amount of moisture, and bread and pastry foods also need to be kept soft, and high conversion syrup and fructose syrup should be used. The hygroscopicity of fructose is the highest among all kinds of sugar.
A higher concentration of sugar liquid can inhibit the growth of many microorganisms. This is because the osmotic pressure of the sugar liquid causes the water in the microbial cells to be absorbed and the growth is inhibited. The osmotic pressure of different sugars is different. The osmotic pressure of monosaccharides is about twice that of disaccharides. Both glucose and fructose are monosaccharides, which have higher osmotic pressure and food preservation effect. The sugar of fructose syrup is grouped into glucose and fructose. The osmotic pressure is also high. Starch syrup is a mixture of sugars. The osmotic pressure increases with the degree of conversion. In addition, the osmotic pressure of the sugar solution is also related to the concentration, which increases as the concentration increases.
The viscosity of glucose and fructose is lower than that of sucrose, and the viscosity of starch sugar syrup is higher, but it decreases as the degree of conversion increases. The high viscosity of starch syrup can be used in a variety of foods to improve the consistency and palatability of products.
Glucose, fructose, and starch syrup are all reductive. These starch sugars have low chemical stability under neutral and alkaline conditions. They are easily decomposed by heat to form colored substances, and they can easily react with protein-containing nitrogen-containing substances to form colored substances. Sucrose does not have reducing properties, and it has high chemical stability under neutral and weakly alkaline conditions, but it is easily decomposed by heating at a pH above 9 to produce colored substances. Starch sugar has high stability to acid and heat and does not easily cause Maillard reaction, and the color of food is stable. If heated at 120 ° C for 90 min at pH3, maltose hardly decomposes; the boiling temperature is as high as 160 ° C. Therefore, it is not easy to scorch when heated, and it is not easy to absorb moisture. In the confectionery industry, it can be used for casting and molding to make hard candy, and the finished product is not easy to retain moisture.
Yeast can ferment glucose, fructose, maltose, and sucrose, but cannot ferment higher oligosaccharides and dextrins. Some foods need to be fermented, such as bread, cakes, etc .; some foods do not need to be fermented, such as preserves, jams, etc. The fermented sugar of starch syrup is divided into glucose and maltose and increases with the degree of conversion. It is better to use high conversion syrup and glucose with high fermented sugar content in the production of fermented bread.