CARBS

• Dietary carbohydrates may be categorized as digestible & Indigestible based on their ability to digest by enzymes present in saliva, stomach or intestin
• Dietary CHO may be categorized as digestible present in the saliva, stomach or intestine or absorbable without digestion
• Food is any substance usually composed of carbohydrates, fats, proteins, water etc that can be eaten or drunk by humans for nutrition.
• The constituents of foods are divided into two major categories: carbohydrates, vitamins, fats, minerals, proteins, enzymes, pigments, flavors, and acids.
• Water is an ever-present and important constituent of food.
• Foods are classified according to their functions in the body into energy-yielding foods, body-building foods, and protection & regulation foods.
• The α-form of glucose has the – OH group on the opposite side from the – CH2OH group, while the β-form has the – OH group on the same side as the CH2OH group.
• Pyranosides are the glycosides of α-D-glucose.
• A carbohydrate containing a five-membered ring is called furanose because furan is the name of a heterocyclic compound whose ring consists of four carbon and one oxygen atom.
• The glycosides of furanose are called furanosides.
• For β-D-glucose, the C1 alcohol points above the plane of pyranose ring.
• The Haworth formula for α-D-glucose shows the C1-OH group below the plane of the pyranose ring.
• Energy-yielding foods include foods rich in carbohydrates and fats, and are divided into pure carbohydrates like sugar, fats & oils, and cereals, pulses, roots & tubers.
• Sugars provide energy and fats and oils also provide a concentrated source of energy.
• Cereals provide in addition to energy large amounts of proteins, minerals and vitamins in the diet.
• This group includes naturally occurring compounds as well as their derivatives such as exudate gums, seaweed gums, seed gums, microbial gums etc.
• Microbial polysaccharides xanthan gum and gellan gum are also important sources of gums.
• Algae polysaccharides, agar, alginate, carrageenan, and locust bean gum are important sources of gums.
• Gums are widely used in the food industry as gelling, stabilizing, and suspending agents.
• The large group of polysaccharides and their derivatives is characterized by its ability to give highly viscous solutions at low concentrations.
• Tree exudate gums, gum arabic, gum ghatti, gum karaya, and gum tragacanth are other sources of gums.
• Fruits including onion, garlic, bananas, asparagus etc contain inulins, which are polymers consisting of fructose units that typically have a terminal glucose.
• Pulses provide proteins and vitamins besides giving energy to the body.
• Roots & tubers mainly provide energy but they also contribute to some extent vitamins & minerals.
• Body-building foods are foods rich in proteins, and are classified into milk, meat, egg & fish, which are rich in proteins of high biological value, and pulses, oil-seeds & nuts, which are rich in protein but may not contain all the essential amino acids required by the human body.
• Protection & regulation foods are foods rich in proteins, vitamins & minerals, and have regulatory functions in the body such as maintaining heart beat, body temperature, clotting of blood & excretion of wastes.
• All the carbon atoms in monosaccharides contain one hydroxyl (–OH) group and sometimes one carbonyl oxygen (as in – CHO, or C=O).
• Monosaccharides are classified into two types based on their functional group: Aldoses and Ketoses.
• The number of carbon atoms in an aldose or ketose may be specified by Triose, Tetrose, Pentose, Hexose.
• Existence of different compounds having same molecular formula but different structural forms are isomers.
• Glucose, Fructose, Galactose are examples of monosaccharides with 3 to 7 carbon atoms.
• Monosaccharides can further be divided on the basis of the number of carbon atoms they possess.
• If the carbonyl oxygen group is present in any other position, the monosaccharide is a ketone derivative that is known as ketoses.
• If the carbonyl oxygen group is present at the terminal position, the monosaccharide is an aldehyde derivative and the sugar is called aldose sugar.
• Monosaccharides exhibit a variety of isomerism such as Aldose-Ketose isomerism, Stereoisomerism, and Optical isomerism.
• In a monosaccharide either an aldehyde or a ketone group is present.
• Examples of monosaccharides with six carbon atoms include Glucose and Fructose.
• Examples of aldose sugars include Glucose and Fructose.
• The carbon atoms in monosaccharides are numbered as C-1 is an aldehyde functional group & C-2 is a ketone functional group.
• Examples of ketose sugars include Fructose and Galactose.