Determining Sugar Content in Food by the Enzymatic Method

1. The Enzymatic method and the importance of determining sugar content in food

- Enzyme tests can quickly and accurately determine the content of different sugars such as glucose, fructose, lactose, sucrose and maltose in products ranging from beverages and dairy products to diet foods and confectionery

- These tests are highly specific and effective even in complex sample matrices, thanks to the use of high-quality enzymes that ensure accurate and precise measurements. The results of these enzyme tests are measured with a spectrophotometer and the process can be automated for maximum efficiency.1.2. The importance of determining sugar content in food

- Enzyme tests can quickly and accurately determine the content of different sugars such as glucose, fructose, lactose, sucrose and maltose in products ranging from beverages and dairy products to diet foods and confectionery.

- Accurate sugar determination is very important for product quality and compliance with nutritional standards. See one of the following sugars to learn more about its relevance in food production.

* Certification and approval by international organizations

Many enzymatic methods have been validated or approved by leading international organizations, ensuring their reliability and standardization in food analysis. The most important of these organizations include:

- AOAC (Association of Official Analytical Chemists)

- CEN (European Committee for Standardization)

- IDF (International Dairy Federation)

- IFU (International Federation of Fruit Juice Producers)

- ISO (International Organization for Standardization)

- OIV (International Organization of Vine and Wine)

2. The significance of the different sugars in food

2.1. Beta Glucan

- Beta Glucan (β-Glucan) is a high molecular weight carbohydrate consisting of linear and branched glucose polymers. At high concentrations it forms "gel" or "membrane" that can block the filters used in breweries. β-Glucan is formed during malt production (from barley), but must not exceed the maximum level before the malt is sold to breweries.

- Therefore, this is the second most important parameter tested in the malt industry, with specific methods registered only for barley and malt.

- β-Glucan is also present in other plants such as mushrooms and grapes, but because it has a molecular structure characteristic of each plant, the tests developed for barley and malt cannot be used.

* The β-Glucan rapid test kits from R-Biopharm:

Enzytec™ Color GlucaTest® (Art. No. E3500 / E3550)

2.2. D-Galactose

- Galactose is a monosaccharide sugar, a molecule that is linked to a glucose molecule and forms a lactose molecule. Therefore, galactose is mainly found in milk and dairy products in the form of the disaccharide lactose. However, the monosaccharide can also be present in free form, not in milk but in dairy products such as cheese.

- D-Galactose can also be found in fruits and vegetables and, in polymeric form, in legumes as stachyose and raffinose.

- In lactose-free dairy products, galactose and glucose are formed in free form through the enzymatic cleavage of lactose. As a component of breast milk, this is an important energy source for infants. Galactose is absorbed in the small intestine and is broken down in the liver by the enzyme galactosidase, or is converted into glycogen by glucose uridine diphosphate.

* The D-Galactose rapid test kits from R-Biopharm include the following products:

- Enzytec™ Liquid D-Galactose (Art. No. E8120)

- RIDA®CUBE D-Galactose (Art. No. RCS4120)

- Enzytec™ Multi-sugar standard low & high (Art. No. E8440 / E8445)

2.3. D-Glucose

- D-glucose is widely present in the animal and plant kingdoms. It is an essential component of carbohydrate metabolism and usually exists in free form together with D-fructose and sucrose. However, more important forms are the di-, tri-, oligo- and polysaccharides (lactose, maltose, sucrose; raffinose, dextrin and starch, cellulose).

- In food, it is present in significant amounts in honey, wine, beer and fruit juice, and in a range of solid foods such as bread and pastries, chocolate and candy. Glucose determination is particularly important in diet products.

* The D-Glucose rapid test kits from R-Biopharm include the following products:

- Enzytec™ Liquid D-Glucose (Art. No. E8140)

- RIDA®CUBE D-Glucose (Art. No. RCS4140)

- Enzytec™ Generic D-Glucose (Art. No. E1210)

- Enzytec™ Multi-sugar standard low & high (Art. No. E8440 / E8445)

2.4. D-glucose/ D-fructose

- D-glucose and D-fructose are present in most plant products. In food, they are present in significant amounts in honey, wine and beer, and in a range of solid foods such as bread and pastries, chocolate and candy. Fructose, or fruit sugar, is a monosaccharide present in many plants, where it is usually linked with glucose to form the disaccharide sucrose.

- In the brewing and wine industry, the total of D-glucose and D-fructose is an important parameter, because it expresses the amount of sugar available for yeast to convert into ethanol.

- In honey, the ratio between the two sugars allows the detection of sugars that are not permitted to be added, such as glucose syrup. D-glucose and D-fructose are measured in many food samples and can be measured separately (as with honey) or at the same time (as with wine).

* The D-glucose/D-fructose rapid test kits from R-Biopharm include the following kits:

- Enzytec™ Liquid D-Glucose / D-Fructose (Art. No. E8160)

- RIDA®CUBE D-Glucose / D-Fructose (Art. No. RCS4160)

- Enzytec™ Generic D-Glucose / D-Fructose (Art. No. E1245)

- Enzytec™ Multi-sugar standard low & high (Art. No. E8440 / E8445)

2.5. Lactose/ D-Galactose

- Lactose is a disaccharide sugar consisting of galactose and glucose. Lactose is an important carbohydrate component of mammalian milk; therefore, it is nutritionally significant. The lactose concentration in milk from healthy cows is about 4,6 to 5 g / 100 g. Lactase (ß-galactosidase), an enzyme present in gastric juice, breaks down lactose into D-galactose and D-glucose. People who lack this enzyme after infancy cannot digest milk and are considered lactose intolerant.

- Determination of the lactose concentration is particularly important for food products labeled as lactose-free. Furthermore, lactose can be used as a sweetener in the food industry and therefore needs to be controlled. D-galactose very rarely occurs in free form; therefore, measurement on the galactose part (lactose/galactose test) is more reliable than measurement on the glucose part (lactose/glucose test).

* The Lactose/D-Galactose rapid test kits from R-Biopharm include the following products:

- Enzytec™ Liquid Lactose / D-Galactose (Art. No. E8110)

- RIDA®CUBE Lactose / D-Galactose (Art. No. RCS4110)

- Enzytec™ Generic Lactose / D-Galactose (Art. No. E1213)

- Enzytec™ Multi-sugar standard low & high (Art. No. E8440 / E8445)

2.6. Lactose/ D-Glucose

- Lactose is a disaccharide consisting of D-galactose and D-glucose and is present in cow's milk at a concentration of about 50 g/L. D-Galactose very rarely occurs in free form and is not present in milk. Therefore, measurement on the galactose part (lactose/galactose test) is more reliable than measurement on the glucose part (lactose/glucose test) when testing food products produced with ordinary milk or without milk.

- When producing lactose-free milk, the disaccharide lactose is hydrolyzed by adding the enzyme lactase (ß-galactosidase), forming D-galactose and D-glucose at about 25 g/L each. The lactose/galactose test cannot be used because the large amount of excess galactose (25 g/L) cannot be removed. For this reason, the excess glucose (25 g/L) must be removed by using glucose oxidase, and the sample is then tested with the lactose/glucose test. R-Biopharm AG provides a special test kit for removing the excess glucose (EnzytecTM Glucose Remover, Product code E3400).

* The Lactose/D-Glucose rapid test kits from R-Biopharm include the following products:

- Enzytec™ Liquid Lactose / D-Glucose (Art. No. E8130)

- RIDA®CUBE Lactose / D-Glucose (Art. No. RCS4130)

- Enzytec™ Glucose remover (Art. No. E3400)

- Enzytec™ Multi-sugar standard low & high (Art. No. E8440 / E8445)

2.7. Maltose/ Sucrose/ D-Glucose

- The malt grain develops the enzymes needed to transform the grain starch into various sugars, including the monosaccharide glucose, the disaccharide maltose, the trisaccharide maltotriose and higher sugars called maltodextrin.

- Glucose syrup (starch syrup) produced from ​​starch using amyloglucosidase also contains maltose. Maltose is measured together with sucrose and D-glucose, because the enzyme α-glucosidase reacts not only with maltose but also with sucrose.

* The Maltose/Sucrose/D-Glucose rapid test kits from R-Biopharm include the following products:

- Enzytec™ Liquid Maltose/Sucrose/D-Glucose (Art. No. E8170)

- Enzytec™ Glucose remover (Art. No. E3400)

- Enzytec™ Multi-sugar standard low & high (Art. No. E8440 / E8445)

2.8. Raffinose

- Raffinose is a trisaccharide consisting of galactose, glucose and fructose. It can be found in beans, beetroot, Brussels sprouts, kale, asparagus, other vegetables and whole grains. Raffinose can be hydrolyzed into D-galactose and sucrose by the enzyme α-galactosidase (α-GAL), an enzyme that is not present in the human digestive tract.

- Humans and other monogastric animals (pigs and poultry) do not have the enzyme α-GAL, and these oligosaccharides pass through the stomach and small intestine without being digested. In the small intestine, they are fermented by gas-forming bacteria that have the enzyme α-GAL and produce carbon dioxide, methane or hydrogen - leading to flatulence that is commonly associated with eating beans and other vegetables.

* The Raffinose rapid test kit from R-Biopharm:

Raffinose (Art. No. 10428167035)

2.9. Starch

- Starch is a polymeric carbohydrate consisting of a large number of glucose units linked together by α-1,4- and α-1,6-glycosidic bonds (amylose, amylopectin). This polysaccharide is produced by most green plants as a reserve of energy. It is the most common carbohydrate in the human diet and is present in large amounts in staple foods such as potatoes, wheat, maize (corn) and rice.

- Starch is an important component of food and animal feed. It acts as a binder, for example in sauces, a filler, a thickener and a structuring agent in the production of many different foods. Partially hydrolyzed starch is also used in soft drinks and is added illegally to alcohol to increase the dry extract (and thus makes the alcohol of better quality).

* The starch rapid test kits from R-Biopharm include the following products:

- Enzytec™ Liquid Starch (Art. No. E8100)

- Starch (Art. No. 10207748035)

- Enzytec™ Generic Starch (Art. No. E1268)

- Enzytec™ Glucose remover (Art. No. E3400)

2.10. Sucrose/D-Glucose

- Sucrose and glucose occupy a central position in the metabolism of plants. In food, they are present in significant amounts in honey, wine, beer and fruit juice, and in a range of solid foods such as bread and pastries, chocolate and candy. Sucrose is also called table sugar, and isolating it from sugarcane and sugar beet is of great economic benefit. When sucrose is hydrolyzed (inverted), D-glucose and D-fructose are formed.

- Sucrose is an important component of food, not only as a sweetener but also because it brings monetary value. There are specific sugar ratios for many fruits and honeys; this can be used as an indicator of the amount of added sugar.

* The sucrose/D-Glucose rapid test kits from R-Biopharm include the following products:

- Enzytec™ Liquid Sucrose / D-Glucose (Art. No. E8180)

- RIDA®CUBE Sucrose / D-Glucose (Art. No. RCS4180)

- Enzytec™ Generic D-Glucose / Sucrose (Art. No. E1246)

- Enzytec™ Glucose remover (Art. No. E3400)

- Enzytec™ Multi-sugar standard low & high (Art. No. E8440 / E8445)

2.11. Sucrose/ Glucose/ Fructose

- Sucrose, D-glucose and D-fructose are present in most plant products and foods. In plant material, D-glucose and D-fructose exist as free sugars and in a range of oligo- and polysaccharides such as fructan (inulin), starch and cellulose.

- In food, they are present in significant amounts in honey, wine, beer and fruit juice, and in a range of solid foods such as bread and pastries, chocolate and candy.

* The Sucrose/Glucose/Fructose rapid test kits from R-Biopharm include the following products:

- Enzytec™ Liquid Sucrose / D-Glucose / D-Fructose (Art. No. E8190)

- RIDA®CUBE Sucrose / D-Glucose / D-Fructose (Art. No. RCS4190)

- Enzytec™ Generic D-Glucose / D-Fructose / Sucrose (Art. No. E1247)

- Enzytec™ Glucose remover (Art. No. E3400)

- Enzytec™ Multi-sugar standard low & high (Art. No. E8440 / E8445)

3. Main benefits of determining sugar parameters in the composition of foods

- Precise compositional analysis: Ensure accurate measurement of sugar, acid, alcohol and other food components, maintaining product quality and consistency.

- Standards compliance: Helps manufacturers meet international standards and regulations, such as the standards set by AOAC, CEN, IDF, IFU, ISO and OIV.

- Quality control: Strengthen the quality control process, ensuring products meet the desired specifications and consumer expectations.

- Versatility: Suitable for many types of food, including fruit juice, wine, beer, dairy products, eggs and meat, making this a useful tool for many segments of the food industry.

- Easy to automate: Create favorable conditions for automation in the laboratory, improving efficiency and accuracy in routine analysis.

Monitoring food components is necessary to maintain the quality, safety and compliance of food products. By using advanced enzyme tests and technologies such as the SureFood® and Enzytec™ product lines, manufacturers can achieve accurate and reliable measurement of key food components. This not only ensures product consistency and consumer satisfaction but also helps meet strict international standards and regulations. Implementing comprehensive compositional testing supports strong quality control and improves overall production efficiency.