Carbs

• Basic structure of a monosacharide

  • Monosaccharides are the simplest form of carbohydrates and are commonly referred to as single sugars.
  • They are composed of carbon (C), hydrogen (H), and oxygen (0) atoms.
  • Examples include glucose, fructose, and galactose.
  • These sugars have a backbone of a single sugar unit, which can be in a linear chain or a ring structure.
• Formation of disaccharides and polysaccharides

  • Disaccharides are formed when two monosaccharides undergo a dehydration reaction, resulting in the formation of a glycosidic bond and the release of water.
  • Common disaccharides include sucrose (glucose + fructose), lactose (glucose + galactose), and maltose (two glucose molecules).
• Polysaccharides

  • Polysaccharides are complex carbohydrates formed by the polymerization of multiple monosaccharide units. They are classified based on their structure and functional properties.
  • Starch, cellulose, and glycogen are examples of polysaccharides, which serve various roles like energy storage (starch and glycogen) and structural functions (cellulose)
• Monosaccharides classification

  Single sugar units like glucose, fructose, and  Galactose
• Disaccharides classification

  Two monosaccharides linked together, such as sucrose, lactose, and maltose.
• Polysaccharides classification

  Complex carbohydrates consisting of many sugar units. Examples include starch (energy storage in plants), cellulose (structural component in plant cell walls), and glycogen (energy storage in animals).
• Monosaccharides sources

  • Glucose: Found in fruits, sweet vegetables, and honey.
  • Fructose: Abundant in fruits, honey, and root vegetables.
  • Galactose: Not commonly found in its free form but is a part of lactose in milk.
• Disaccharide sources

  • Sucrose: Common sugar (table sugar), found in sugar cane, sugar beets, and fruits.
  • Lactose: Found in milk and dairy products.
  • Maltose: Produced during the breakdown of starch in germinating seeds, like barley.
• polysaccharides sources

  • Starch: Majorly found in foods like potatoes, grains (rice, wheat), and legumes.
  • Cellulose: Present in the cell wall of plants, hence in all plant-based foods like vegetables, fruits, and whole grains.
  • Pectin: Found in fruits such as apples, plums, and citrus fruits. Used as a gelling agent in jams and jellies.
  • Non-Starch Polysaccharides (Dietary Fibre): Includes cellulose, hemicelluloses, pectins, and gums. Found in whole grains, fruits, vegetables, nuts, and seeds.
• Properties- sweetness

  • Carbohydrates, especially simple sugars like glucose and fructose, are known for their sweet taste.
  • The degree of sweetness varies among different carbohydrates. Fructose is the sweetest, followed by sucrose and glucose.
• Properties- solubility

  • solubility in water.
  • Monosaccharides and disaccharides are generally soluble in water
  • Polysaccharides like starch have limited solubility in cold water but can absorb water and swell.
• Gelatinisation of starch

  • Gelatinisation occurs when starch granules absorb water and swell upon heating.
  • This process is critical in cooking and baking, as it thickens sauces and gives structure to baked goods.
• Hydrolysis

  • In hydrolysis, carbohydrates are broken down into simpler molecules by the addition of water.
  • This includes the breakdown of disaccharides into monosaccharides (e.g., sucrose into glucose and fructose).
• Inversion

  Inversion is the process of converting sucrose into glucose and fructose, especially in the making of sweets and syrups.
• Crystallisation

  • Crystallisation refers to the formation of sugar crystals from a concentrated solution of sugar.
• Caramelisation

  • Caramelisation is the browning of sugar, which occurs through the application of heat, producing a distinctive flavour and colour.
• Dextrinisation

  Dextrinisation involves the breakdown of starch into dextrins due to dry heat, resulting in colour and flavour changes, as seen in toasted bread.
• Pectin extraction and gel formation

  • Pectin, found in fruits, is extracted and used as a gelling agent in jams and jellies.
  • It forms a gel when heated with sugar and acid, essential in preserving fruits.
• Effects of heat

  • Dry heat causes caramelisation and dextrinisation.
  • Moist heat leads to gelatinisation of starch and hydrolysis of carbohydrates.
• effects of enzymes

  • Enzymes like amylase break down carbohydrates during digestion.
  • They convert complex carbohydrates into simpler sugars, facilitating absorption.
• Biological functions

  • Sugars: Quick source of energy, essential for brain function, and as a dietary energy source.
  • Starch: Major energy reserve in plants, slowly releases glucose for sustained energy.
  • Non-Starch Polysaccharides: Includes dietary fibres that aid in digestion, prevent constipation, and help in weight management.
• Culinary functions

  • Sugars: Provide sweetness, contribute to the texture and colour of foods, act as preservatives.
  • Starch: Thickening agent in sauces and gravies, provides structure in baking.
  • Pectin: Used as a gelling agent in jams and jellies, stabilises foods.
• Energy

  • Carbohydrates are the primary energy source in the average diet, contributing significantly to the body's energy needs.
  • used for various bodily functions such as muscle movement, brain function, and maintaining body temperature.
  • primary sources : grains, fruits, veg
• • Non-starch polysaccharides, also known as dietary fibre, are essential for maintaining healthy digestion.
  • Dietary recommendations suggest a daily intake of approximately 25-30 grams of fibre.
  • This can be achieved by including a variety of fruits, vegetables, whole grains, legumes, nuts, and seeds in the diet.
• Hydrolysis

  • Hydrolysis is the chemical breakdown of carbohydrates into simpler sugars, facilitated by enzymes and water.
  • It involves the cleavage of glycosidic bonds in polysaccharides and disaccharides, converting them into monosaccharides
• Digestion

  • Digestion of carbohydrates begins in the mouth with the enzyme salivary amylase, which starts breaking down starch.
  • In the small intestine, pancreatic amylase continues the process, breaking down remaining starch into maltose.
  • Further digestion is carried out by enzymes in the intestinal lining, which break down disaccharides into monosaccharides.
• Absorption

  • Monosaccharides like glucose, fructose, and galactose are absorbed directly into the bloodstream through the intestinal wall.
  • They are then transported to the liver, where they are metabolised or distributed throughout the body as a source of energy.
• Utilisation of glucose

  • Glucose is the primary energy source for cells.
  • It is either used immediately for energy or stored as glycogen in the liver and muscles for later use.
  • Excess glucose can be converted into fat and stored in adipose tissue
• Disease prevention

  dietary fibre is linked to reduced risk of chronic diseases such as diabetes and heart disease.