The Scientific Study of Food

Measurement Units Food’s energy value can be quantified in calories or joules, with kilocalories being a common larger unit of energy. The international unit for energy is the “joule.” Kilocalories represent the heat required to raise the temperature of a thousand grams (1000) of water by 1 degree Celsius. For instance, one gram (gm.) of […]

Measurement Units

Food’s energy value can be quantified in calories or joules, with kilocalories being a common larger unit of energy. The international unit for energy is the “joule.” Kilocalories represent the heat required to raise the temperature of a thousand grams (1000) of water by 1 degree Celsius. For instance, one gram (gm.) of carbohydrates yields four kilocalories, one gram of protein yields four kilocalories, and one gram of fat yields nine kilocalories.

Food Weight: Raw or processed food weight can be expressed in grams or kilograms.

1 kilogram = 1000 grams.

Macronutrients are measured in grams, while vitamins and trace elements, needed in smaller quantities by the body and present in food in small amounts, are measured in milligrams (mg.) and micrograms (μg.).

 

1g = 1000mg (10^3mg)

1gm = 1,000,000g (10^6g)

Or

1mg = 0.001 or 10^-3g

1g = 0.000001g or 10^-6g

Other commonly used units for measuring vitamins are the international unit (I.U) and standard unit (S.I).

Effects of Heat on Nutrients

Effects of Heat on Carbohydrates:

  1. Carbohydrates undergo dextrinization, breaking down into simpler units for easier digestion.
  2. In moist heat, carbohydrates gelatinize, expanding and bursting, making them more digestible.
  3. Carbohydrates caramelize, turning brownish, usually with dry heat.

 

Effects of Heat on Proteins:

  1. Heat denatures proteins, altering their primary structure and state, as seen in eggs and beans.
  2. Proteins contract, causing food to shrink, as in meat.
  3. Overcooking proteins results in toughness and indigestibility, as with fried fish.

 

Effects of Heat on Fats and Oils:

  1. Fats change from a solid to a liquid state when heated.
  2. Oil produces a blue haze at its smoke point (2000-2100°F), indicating potential combustion.
  3. Heating oil beyond the smoke point leads to decomposition, producing a poisonous substance.

Related Posts:

Absorption

Digestive System

Dietary Deficiency

Mineral Elements | Macro Elements, Micro Elements & Water

Vitamins

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