This MCQ module is based on: Essential Food Components (Macronutrients and Micronutrients)
Essential Food Components (Macronutrients and Micronutrients)
Study Notes and Summary
Nutrients: Food components that provide energy, support growth, help repair and protect the body from diseases, and maintain various bodily functions are called nutrients.
Major Nutrients: The primary nutrients include carbohydrates, proteins, fats, vitamins, and minerals. Dietary fibers (roughage) and water are also essential components of our diet.
Energy-Giving Foods (Macronutrients):
Carbohydrates: Primary sources of energy. Examples include cereals (wheat, rice, maize), vegetables (potato, sweet potato), and fruits (banana, pineapple, mango). Common sugar is also a carbohydrate. Glucose provides instant energy.
Fats: Source of stored energy. Fats can be from plant sources (nuts, seeds) or animal sources (ghee, oils, butter). Laddoos, rich in ghee and nuts, provide warmth and energy, especially in winters.
Both carbohydrates and fats are termed “energy-giving foods” as they provide energy for various activities. Polar bears accumulate fat for energy during hibernation.
Body-Building Foods (Proteins):
Proteins: Essential for growth and repair of the body. They are called “body-building foods”.
Sources: Good sources include milk products and pulses. Plant sources are pulses, beans, peas, and nuts , while animal sources include milk, paneer, egg, fish, and meat. Edible mushrooms are also good sources of protein.
Growing children require adequate protein for proper growth and development.
Protective Nutrients (Micronutrients):
Vitamins and Minerals: Required in small amounts but are essential for health. They protect the body from various diseases.
Vitamin A: Keeps eyes and skin healthy. Deficiency causes poor vision or loss of vision (night blindness). Sources: Papaya, carrot, mango, milk.
Vitamin B1: Keeps heart healthy and supports various bodily functions. Deficiency causes Beriberi (swelling, tingling, or burning sensation in feet and hands, trouble in breathing). Sources: Legumes, nuts, whole grains, seeds, milk products.
Vitamin C: Helps the body fight diseases. Deficiency causes Scurvy (bleeding gums, slow healing of wounds). Sources: Amla, guava, green chilli, orange, lemon. James Lind’s observations in 1746 showed that lemons and oranges cured scurvy in sailors.
Vitamin D: Helps the body absorb calcium for bone and teeth health. Deficiency causes Rickets (soft and bent bones). Sources: Exposure to sunlight, milk, butter, fish, eggs. Vitamin D can be naturally produced by the body upon sunlight exposure.
Calcium: Keeps bones and teeth healthy. Deficiency causes bone and tooth decay (weak bones, tooth decay). Sources: Milk/soya milk, curd, cheese, paneer.
Iodine: Helps perform physical and mental activities. Deficiency causes Goitre (swelling at the front of the neck). Sources: Seaweed, water chestnut, iodised salt. Iodised salt is common salt mixed with iodine salts.
Iron: Important component of blood. Deficiency causes Anaemia (weakness, shortness of breath). Sources: Green leafy vegetables, beetroot, pomegranate.
Some nutrients, like Vitamin C, can be lost during cooking due to high heat. Washing cut or peeled vegetables can also lead to vitamin loss.
Other Essential Components:
Dietary Fibres (Roughage): Do not provide nutrients but are essential for the body to get rid of undigested food and ensure smooth passage of stools. Sources: Green leafy vegetables, fresh fruits, wholegrains, pulses, nuts.
Water: Helps the body absorb nutrients from food and removes waste through sweat and urine. Many food sources provide water to the body.
Practice MCQs
Assessment Worksheets
This assessment will be based on: Essential Food Components (Macronutrients and Micronutrients)
Experiment-Based Theories for Olympiad Preparation
Hypothetical Experiment: Impact of pH on Vitamin C Stability in Fruit Juices
Objective: To demonstrate how the pH of a solution (simulating different food environments) affects the stability and degradation rate of Vitamin C, a common protective nutrient. This expands on the chapter’s discussion of Vitamin C deficiency and its sources.
Advanced Concept Connection: This experiment introduces the concept of pH influence on chemical stability, particularly for vitamins, and its relevance in food science and preservation. For Olympiad preparation, it deepens understanding of nutrient chemistry, enzyme activity (though not directly measured, pH affects enzyme activity), and the scientific basis for food processing and storage recommendations. It highlights the importance of environmental factors in nutrient bioavailability.
Materials: Fresh orange juice (known source of Vitamin C), lemon juice (acidic), distilled water (neutral control), baking soda solution (alkaline), Vitamin C test kit (iodine titration or indicator strips), three identical test tubes/small beakers, measuring droppers/pipettes, stopwatch.
Procedure:
Solution Preparation:
Test Tube 1 (Acidic): Add 5 ml of orange juice and 1 ml of lemon juice.
Test Tube 2 (Neutral): Add 5 ml of orange juice and 1 ml of distilled water.
Test Tube 3 (Alkaline): Add 5 ml of orange juice and 1 ml of baking soda solution.
Initial Vitamin C Measurement: Immediately after preparing each mixture, take a small sample from each test tube and perform the Vitamin C test. Record the initial readings (e.g., number of drops of iodine solution required for color change).
Observation Over Time: Let the test tubes stand at room temperature for a set duration (e.g., 30 minutes, 1 hour, or longer).
Final Vitamin C Measurement: After the set duration, perform the Vitamin C test again on samples from each test tube. Record the final readings.
Data Analysis: Compare the initial and final Vitamin C levels in each test tube. Calculate the percentage degradation or change in Vitamin C content for each pH condition.
Expected Observations: You would observe that the Vitamin C content decreases in all solutions over time, but the degradation is most pronounced in the alkaline solution (Test Tube 3) and least in the acidic solution (Test Tube 1). The neutral solution (Test Tube 2) would show an intermediate degradation rate.
Theoretical Outcomes: This experiment demonstrates that Vitamin C (ascorbic acid) is more stable in acidic environments and degrades more rapidly in neutral or alkaline conditions. This is because Vitamin C is susceptible to oxidation, and high pH can accelerate this process. The presence of other compounds in fruit juices can also influence stability, but the primary factor observed here is pH. This concept explains why citrus fruits are excellent sources of Vitamin C, as their inherent acidity helps preserve the vitamin.
Real-Life Connections:
Food Preservation: This knowledge is crucial in food processing; for example, using acidic conditions (like adding lemon juice) to prevent browning (oxidation) in cut fruits and vegetables, which also helps retain Vitamin C.
Dietary Advice: It reinforces the benefit of consuming fresh, slightly acidic fruits and vegetables for optimal Vitamin C intake.
Pharmaceuticals: The stability of Vitamin C in various formulations (e.g., supplements) is carefully controlled by adjusting pH.
Cooking Techniques: It explains why prolonged boiling or cooking with alkaline ingredients (like baking soda) can significantly reduce the Vitamin C content of vegetables.
