krit.club logo

Mindful Eating: A Pathway to Health - Test for Fats

Grade 6CBSE

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

•

Fats are essential nutrients that serve as the body's secondary energy source and are stored for later use.

•

The energy provided by 1 g1 \text{ g} of fat is significantly higher than that provided by 1 g1 \text{ g} of carbohydrates. Specifically, fats provide approximately 9 kcal/g9 \text{ kcal/g}.

•

A simple physical test called the 'Paper Patch Test' is used to detect the presence of fats in food items.

•

A 'Translucent Patch' is a spot on the paper that allows light to pass through partially, which is a characteristic indicator of lipids (fats/oils).

•

When performing the test, it is important to let the paper dry to ensure that any 'wet' patch observed is not due to water content in the food.

•

Common sources of fats include butter, ghee, vegetable oils, nuts (like groundnuts), and animal fats.

📐Formulae

Food Sample+Paper→Crushing/RubbingTranslucent Patch=Presence of Fat\text{Food Sample} + \text{Paper} \xrightarrow{\text{Crushing/Rubbing}} \text{Translucent Patch} = \text{Presence of Fat}

Energy from Fat≈2.25×Energy from Carbohydrates\text{Energy from Fat} \approx 2.25 \times \text{Energy from Carbohydrates}

Total Energy (kcal)=(Mass of Fat in g×9)+(Mass of Carbohydrates in g×4)+(Mass of Protein in g×4)\text{Total Energy (kcal)} = (\text{Mass of Fat in g} \times 9) + (\text{Mass of Carbohydrates in g} \times 4) + (\text{Mass of Protein in g} \times 4)

💡Examples

Problem 1:

A student takes a small piece of butter and rubs it on a white sheet of paper. After waiting for 55 minutes, the patch remains and allows some light to pass through. What is the conclusion?

Solution:

The food sample (butter) contains fats.

Explanation:

Butter is rich in lipids. When rubbed on paper, it leaves an oily residue. Unlike water, fats do not evaporate at room temperature quickly, leaving a permanent translucent patch which is the standard positive result for the fat test.

Problem 2:

Calculate the approximate energy in kilocalories (kcal) provided by a snack containing 10 g10 \text{ g} of fat and 20 g20 \text{ g} of carbohydrates.

Solution:

10 g×9 kcal/g+20 g×4 kcal/g=90+80=170 kcal10 \text{ g} \times 9 \text{ kcal/g} + 20 \text{ g} \times 4 \text{ kcal/g} = 90 + 80 = 170 \text{ kcal}

Explanation:

Fats provide 9 kcal9 \text{ kcal} per gram and carbohydrates provide 4 kcal4 \text{ kcal} per gram. By multiplying the mass of each nutrient by its energy constant, we find the total energy content.

Problem 3:

During a science experiment, a student crushed a piece of apple on paper. Initially, a patch appeared, but after 1010 minutes of drying in the sun, the patch disappeared. Does the apple contain significant fat?

Solution:

No, the apple does not contain a significant amount of fat.

Explanation:

The initial patch was caused by the water content (H2OH_2O) in the apple. Since the patch disappeared upon drying, it indicates the absence of non-volatile oils or fats, which would have left a permanent translucent mark.