CamScanner Features Quiz

Disaccharides

• Disaccharides are formed when two monosaccharides combine in a dehydration reaction
• They consist of two monosaccharides linked together by a glycosidic bond
• Common disaccharides include maltose, lactose, and sucrose
• The most common disaccharides are maltose, lactose, and sucrose

Monosaccharides and Disaccharides (Combining)

• Glucose + Glucose = Maltose + H₂O
• Glucose + Galactose = Lactose + H₂O
• Glucose + Fructose = Sucrose + H₂O

Classification of Disaccharides

• Reducing disaccharides have a free aldehyde or ketone group
  • Examples: Maltose and Lactose
• Non-reducing disaccharides do not have a free aldehyde or ketone group
  • Example: Sucrose

Properties of Disaccharides

• Disaccharides are crystalline, water-soluble, and sweet
• They are classified as reducing or non-reducing based on the presence of a free aldehyde or ketone group
• Solubility varies; sucrose is very soluble, maltose is fairly soluble, and lactose is only slightly soluble

Disaccharides Formation

• Disaccharides are formed when two monosaccharides are joined by a dehydration synthesis reaction

Types of Oligosaccharides

• Oligosaccharides contain 2-10 monosaccharide units
• They are classified based on the number of monosaccharide units (e.g., disaccharides, trisaccharides, tetrasaccharides, pentasaccharides)

Importance of Oligosaccharides

• They are not digested by human gastric glands
• They are consumed by intestinal microflora
• They help in growth of microflora that reduce pathogens
• They reduce toxins and protect the liver
• They offer benefits for constipation, cholesterol, and glucose metabolism
• They might have anticancer effects

Oligosaccharide Groups

• Sucrose-related oligosaccharides
• Starch-related oligosaccharides
• Lactose-related oligosaccharides
• Other oligosaccharides

Properties of Oligosaccharides

• Lower sweetness intensity than sucrose
• Calorie-free
• Resistant to hydrolysis by digestive enzymes
• Non-cariogenic, inhibit the growth of Streptococcus mutans
• Higher solubility compared to sucrose
• Heat-stable, do not degrade with heating
• Hydrolyze in an acidic environment

Benefits of Oligosaccharides

• Enhance bifidus bacteria in the colon
• Improve lactose digestion and metabolism
• Increase mineral absorption
• Improve HDL/LDL ratio
• Reduce serum lipids and blood cholesterol
• Lower blood pressure
• Reduce the glycemic response
• Decrease toxic and carcinogenic metabolites in feces

Legal Status of Oligosaccharides

• Not labeled as carbohydrates or sugars
• Not food additives
• Considered food ingredients
• No restrictions on application

Lactosucrose

• A tri-saccharide composed of glucose, galactose, and fructose
• Has prebiotic effects
• Promotes intestinal mineral absorption
• Naturally present in some yogurts when sucrose and lactose are present in milk
• Produced on a large scale through a reaction involving the enzyme fructosyltransferase

Lactose

• A disaccharide composed of galactose and glucose
• Also called milk sugar
• Requires the enzyme lactase for digestion
• Widely used in the food industry
• Present in the urine of pregnant women (giving a positive Cu²+ test)
• A reducing sugar

Maltose

• A disaccharide composed of two glucose molecules
• Formed during the digestion of starch
• A reducing sugar

Raffinose

• A trisaccharide composed of glucose, fructose, and galactose.
• Occurs in some plants
• Not easily digested by humans, leading to potential digestive issues

Stachyose

• A tetrasaccharide, with a structure similar to raffinose, but with an additional galactose unit.
• Found in many plants
• Difficult for human digestion

Verbascose

• A pentasaccharide composed of multiple units of glucose, fructose, and galactose.
• Found in some plants
• Highly indigestible for humans

Melezitose

• A trisaccharide found in honey and some plants
• Present in various plant saps and honey

Cycloheptamylose

• A heptasaccharide derived from starch
• Useful in chromatographic separations

Classification of Carbohydrates

• Carbohydrates are classified into monosaccharides, oligosaccharides, and polysaccharides
• Monosaccharides are the simplest form, while polysaccharides are formed from many monosaccharide units
• Different types of monosaccharides, such as trioses, tetroses, pentoses, hexoses, and heptoses exist. Specific examples are given, along with examples of disaccharides, trisaccharides, tetrasaccharides, and pentasaccharides. Polysaccharide examples like starch and glycogen are mentioned, as well as heteropolysaccharides.