Chemical Composition of Food

Question 1

Proximate components (7)

Answer 1

• water (moisture)
• proteins
• fats (lipids)
• carbohydrates (sugar, dietary fiber)
• vitamins
• minerals (collectively as ash)

Question 2

• Known to have a chemical composition of Cx(H20)y

- Contributes to sweetness, chemical reactivity, polymer functionality

Answer 2

Carbohydrates

Question 3

carbohydrates are divided as:

Answer 3

simple (sugars)

complex (polysaccharides)

Question 4

simple carbs: sugars (4)

Answer 4

monosaccharides
disaccharides
oligosaccharides
sugar alcohols (polyols)

Question 5

complex carbs: polysaccharides

Answer 5

digestible

dietary fiber

Question 6

single sugar unit

Answer 6

monosaccharides

Question 7

• known as blood sugar
• mild sweet flavor
• essential energy source

Answer 7

glucose

Question 8

• sweetest of all sugars
• found in fruits and honey
• most common sweetener used in soft drinks, cereals, etc

Answer 8

fructose

Question 9

• hardly taste sweet

- rarely exists as a single sugar unit

Answer 9

galactose

Question 10

disaccharides

Answer 10

-Pairs of monosaccharides
-Combined by condensation,
separated by hydrolysis

Question 11

Maltose

Answer 11

• glucose + glucose
• not abundant
• produced upon starch breakdown

Question 12

Sucrose

Answer 12

-fructose + glucose
-Bears a sweet taste (fruit,
vegetables and grains)
-table sugar that is refined
from sugarcane and/ or sugar beets

Question 13

Lactose

Answer 13

• Galactose + Glucose
• Known as milk sugar
• Primary carbohydrate of milk

Question 14

Oligosaccharides

Answer 14

• Short-chain sugars made of monosaccharides

- 3- 10 sugar units

Question 15

Raffinose, Stachyose and Verbascose

Answer 15

-Composed of Galactose,
Glucose and Fructose
-Found in seeds (legumes)
-Cannot be enzymatically
broken

Question 16

-Non-sugar carbohydrates
༝ Chemical composition
resembles one part (CHO)
one part alcohol
༝ Commonly used as
sweetener
༝ Erythritol, Xylitol,
Mannitol, Sorbitol, Isomalt, Maltitol, Lactitol

Answer 16

Sugar alcohols (Polyols)

Question 17

More than 10 sugar units

Answer 17

Digestible Polysaccharides

Question 18

Major source of carbohydrates in the human diet
༝ Stored in plant cells
༝ Occurs as “granules”

Answer 18

Starch

Question 19

Partially hydrolyzed starch in which glucose chains are reduced
༝ Hydrolysis can be done by heat or by enzymes

Answer 19

Dextrins

Question 20

Found only in meats and animal tissues (liver and muscles)

Allows for breakdown to produce energy

Answer 20

Glycogen

Question 21

Types of polysaccharides that are indigestible

༝ Can be fermented by colonic bacteria

Answer 21

Dietary Fiber

Question 22

• resp for the woody texture of plants

- contributed to the characteristic aroma and taste of wood

Answer 22

Lignins

Question 23

• Principal component of plant cell walls

- Responsible for the structure of vegetables and its crisp texture

Answer 23

Cellulose

Question 24

• Heterogenous branched polymers found in plant cell walls

- Composed of uronic acids (sugar acids) and sugars

Answer 24

Hemicellulose

Question 25

Commonly present in fruits that adheres cell walls.

Answer 25

Pectin

Question 26

Water- soluble polysaccharides commonly used for thickening, stabilizing and emulsifying.

Answer 26

Gums