Midterm T.1

Question 1

Analytical Method and Method Principle: water

Answer 1

Analytical Method: Vacuum oven
Method Principle: weight loss due to drying

Question 2

Analytical Method and Method Principle: protein

Answer 2

Analytical Method: Kjeldahl
Method Principle: Sulphuric acid digestion: calculate protein from N2

Question 3

Analytical Method and Method Principle: lipid

Answer 3

Analytical Method: Soxhlet
Method Principle: Solvent extration of lipid

Question 4

Analytical Method and Method Principle: minerals (ash)

Answer 4

Analytical Method: Muffle Furnace
Method Principle: Weight of ash

Question 5

Analytical Method and Method Principle: carbohydrate

Answer 5

Method Principle: calculated by difference

Question 6

Types of Monosaccharides

Answer 6

Pentoses (5C)
Hexoses (6C)
glucose fructose galactose

Question 7

Types of Complex Carbohydrate

Answer 7

oligosaccharides: combination of 3-10 monosaccharides

polysaccharides: chains of oligosaccharides: starch, cellulose, pectin, hydrocolloids

Question 8

Types of Disaccharides

Answer 8

sucrose: table sugar; glucose + fructose

lactose: glucose + galactose

maltose: glucose + glucose

Question 9

Functions of Sugars in Foods

Answer 9

crystallization (characteristic products)

body and mouthfeel (viscosity)

humectant (hygroscopic, attract and hold water, preservation effect at high levels

source of food for yeast and bacteria (fermentation)

browning reactions (Maillard reaction and Carmelization)

Question 10

Browning Reaction: Caramelization

Answer 10

sugar decomposition at high temperature creates brown polymers

with heat, table sugar (sucrose) can be broken down into glucose and fructose

Question 11

Browning Reaction: Maillard Reaction

Answer 11

reducing sugar and amino acids react with dry heat

Question 12

Complex carbohydrates are added to foods to

Answer 12

increase dietary fibre (cellulose)

thicken foods (gums starch)

form gels (pectin, starch)

bind water (pectin)

stabilize proteins (carrageenan)

Question 13

Types of Polysaccharides

Answer 13

starches
long chains of glucose units
amylose (linear, gel formation (gummy ears)
amylopectin (brained chains, viscosity)

cellulose (major component of plant cell walls)

pectin (intercellular cement in fruits and vegatables)

gums ( thicken and stabilize)

Question 14

Carbs not digested by humans are

Answer 14

dietary fibre

Question 15

High fructose corn syrup (HFCS)

Answer 15

derived from glucose hydrolyzed from corn starch
some glucose molecules (42 or 55%) are isomerized to fructose