CHAPTER 18

CLASSIFICATION OF FOOD

INTRODUCTION

Food can be classified by its origin, by its chemical composition as per their nutritive values and according to predominant functions of food.

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CLASSIFICATION OF FOOD

The food can be classified on the various basis as follows:

• On the basis of origin.
• On the basis of chemical.
• On the basis of predominant.
• On the basis of nutritive value.

Classification of Food by Origin

• Foods of animal origin: It includes milk, meat, fish, egg.
• Foods of vegetable/plant origin: It includes cereals, millets, pulses, oil seeds, nuts, fruits and vegetables.

Classification of Food by Chemical Composition

Macronutrients

Proteins

• It is a macronutrient. In Indian diet, it contributes 7–15% of total energy intake of daily requirement. Proteins are complex organic nitrogenous compounds. Proteins are formed from simpler units called amino acids.
• There are 10 essential amino acids (EAA) and 10 nonessential amino acids (Non-EAA).

Sources of Proteins

• Meat, cheese, egg, milk, beans, peas, pulses, fish, nuts, etc.

Functions of Proteins

• The functions of proteins are as follows:
• Used as enzymes catalyzing many chemical reaction of the cell.
• They serve as structural components of cells.
• They are general body builds.
• Helps in repair and maintenance of body tissue

Fats or Lipids

Fats and their derivatives are collectively known as lipids or oils. They are solid at 20°C. They contain twice as much energy as carbohydrates. It contributes 10–30% of total energy intake. They are said to be energy-rich compounds

Fatty Acids

Fat yields fatty acids and glycerols on hydrolysis. Fatty acids are divided into saturated fatty acids such as lauric, palmitic, and stearic acids and unsaturated fatty acids are further divided into monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA).

Classification

• Simple lipid
• Compound lipids
• Derived lipids

Sources

• Vegetable oil, butter, meat, milk, ghee, groundnut, coconut, cereals, pulses and vegetables, etc.
• Visible fats are those that are separated from their natural sources like ghee, oil, etc.
• Invisible fats are those which are not visible through naked eye.
• Give energy 9 kcal (37 kJ)/g

Carbohydrates

Carbohydrates are a group of compounds containing carbon, hydrogen and oxygen. They are commonly known as starches or sugars or saccharides. They are chief energy producers of our body. Carbohydrates provide energy 4 kcal (17kJ)/g.

Classification

• Monosaccharides
• Disaccharides
• Polysaccharides

Micronutrients

Minerals

More than 50 chemical elements are found in the human body which are required for growth, repair, and regulation of vital body functions. Mineral salts serve to regulate the different metabolic activities. Mineral can be divides in two groups:

• Major: Calcium, phosphorus, sodium, potassium, magnesium, chlorine.
• Trace elements minerals: Iron, iodine, fluorine, zinc, copper, cobalt, chromium, manganese.
• Trace minerals with no known function: Lead, mercury, boron, aluminium.

Vitamins

Vitamins are a class of organic compound comes under category of micronutrients. Since the body is generally unable to synthesize them in sufficient amounts, they must be taken by food. They are broadly as water-soluble and fat-soluble vitamins.

• Fat-soluble vitamins: Vitamins A, D, E and K are fat-soluble vitamins.
• Water-soluble vitamins: Vitamins B (B1, B2, B3, B5, B6, B7, B9 and B12) and C are readily soluble in water

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Water

All biochemical activities take place in water, making it an essential nutrient at every age and a vital part of overall health. It fills the spaces in and between cells and helps to form structures of large molecules such as protein and glycogen.

Classification of Food by Predominant Function

• Energy-yielding Food

This group includes foods rich in carbohydrates and fats and also pure fats and carbohydrates.

• Body Building Food

Food rich in proteins are called body building foods. Milk, egg, meat and fish rich in protein of high biological value.

• Protective Food

Foods rich in proteins, vitamins and minerals are termed protective foods.

Classification of Food by Nutritive Value

• Cereals and Millets
• Vegetables
• Nuts and Oilseeds
• Fruits
• Animal Foods
• Fats and Oils
• Sugar and Jaggery
• Condiments and Spices
• Beverages

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