Food Chemistry

Introduction• Food Chemistry: the study of producing, processing,

preparing, evaluating, and using food

• The study of how your body uses the food you eat is nutrition

• Substances that are found in food and needed by the body to function, grow, repair itself and produce energy are called nutrients

• Your body needs over 50 different nutrients which can be divided into 6 classes: Carbohydrates

FatsProteins

VitaminsMineralsWater

Major Biomolecules

• Carbohydrates

• Fats

• Protein

CarbohydratesMade up of C, H, and O in a 1 : 2 : 1 ratio

• Functions– Provides body main

source of energy (quick energy)

– Provide bulk– Helps the body digest

fats• Types– Simple –Sugars (basic bldg blocks – mono = 1)

– Complex• Starches and Fiber (Di = 2, Poly = many)

• Sources:– Sugars—honey, jam– Fiber sources—fruits,

vegetables, whole grains

– Starch sources—breads, cereals, pasta

Carbohydrates structure

Classified as simple or complex, based on the number and structure of the sugar molecule they contain:

-Monosaccharides = simple sugars

-Polysaccharide = complex sugars

Fats Made up mostly of C and H with some O

• Functions– Provides energy– Carries fat-soluble

vitamins– Protects vital organs

and provides insulation– Provides essential fatty

acids• Types– Fatty Acids– Cholesterol

• Types– Fatty Acids• Saturated –raises LDL• Polyunsaturated-

decreases LDL• Monounsaturated-

decreases LDL and increases HDL

– Cholesterol• LDL-”bad cholesterol”• HDL-”good cholesterol”

Sources of Fats

• Cheese• Butter• Nuts• Meats• Dressings• Chocolate

Fats structure

a. Saturated fats form when each carbon atom in the fatty acid chain is joined to another carbon atom by a single covalent bond • Solid at room temperature (Ex: butter)

b. Unsaturated fats form when there is a least one carbon-carbon double bond• liquid at room temperature (ex: Olive oil)

c. Polyunsaturated fats form when there are two or more carbon-carbon double bonds• liquid at room temperature (ex: Corn, sesame & peanut oil)

Proteins Made up of C, H, O, and N

• Functions– Build and repair tissues– Help body make

important substances– Regulate body

processes– Supply energy

• Types– Complete: contains

adequate amounts of all essential amino acids

– Incomplete: Lacks some amino acids

• Sources– Meat-Complete– Milk-Complete– Eggs-Complete– Fish-Complete– Nuts-Incomplete– Legumes-

Incomplete

Protein structure

• Proteins are polymers of amino acids

Dietary Guidelines

• 55 % of person’s calories should come from carbohydrates

• 15 % from protein• 30% or less from fat

Vitamins

• Can be divided into two main categories• Fat-soluble vitamins– dissolve in fats– can be stored in fatty tissues of the body

• Water-soluble vitamins– dissolve in water– are not stored in the body

Fat-Soluble Vitamins

Water-Soluble Vitamins

Minerals

• Minerals can also be divided into two categories:

• Macrominerals are needed in amounts of 100 mg or more per day.

• Trace elements are needed in amounts less than 100 mg per day.

Macrominerals

Trace Minerals

Excess Nutrients

• As with everything, too much of any one thing is not good for you and the same thing goes for nutrients.

• Excess energy nutrients-carbohydrates, fats, and proteins-can lead to unhealthy weight gain

• Excesses of some vitamins and minerals can lead to toxicity (poisoning) and other complications

Food Labels= must be on all packaged foods as of 1990 federal law

D. Nucleic Acids1. Made up of C, H, O, N, and P2. Uses:

a. Store and transmit genetic informationb. Make proteins

3. Made up of nucleotidesa. 5 – Carbon sugarb. Phosphate groupc. Nitrogenous base

4. Example: DNA and RNA