Lesson 2

Question 1

Dispersed phase

Answer 1

The substance dispersed within another

Question 2

Continuous phase

Answer 2

The continuous substance around the dispersed phase

Question 3

Solid in liquid

Answer 3

Sol (starches)

Question 4

Liquid in solid

Answer 4

Gel (Jams, jellies)

Question 5

Gas in liquid

Answer 5

Foams (whipped egg whites)

Question 6

Gas in solid

Answer 6

Solid foam (ice cream)

Question 7

Liquid in liquid (2 immiscible liquids)

Answer 7

Emulsion (mayonnaise)

Question 8

Liquid in solid

Answer 8

Solid emulsion (butter)

Question 9

How many calories in carbohydrates

Answer 9

4 cal/g

Question 10

What are the monosaccharides?

Answer 10

Glucose, fructose, galactose

Question 11

What are the disaccharides?

Answer 11

Sucrose (glucose and fructose), lactose (glucose and galactose), maltose (glucose and glucose)

Question 12

How is honey made?

Answer 12

Nectar contains sucrose which is broken into its components (fructose and glucose 60:40) by invertase in the bees saliva. Some glucose is made into gluconic acid and hydrogen peroxide by glucose oxidase, which act as preservative to the nectar.

Question 13

What enzyme do lactose intolerant people not have?

Answer 13

Lactase - breaks lactose down

Question 14

How is lactic acid made?

Answer 14

Lactose is fermented by lactic acid producing bacteria, which is a preservative agent in yogurt and some cheeses

Question 15

How do you get maltose?

Answer 15

Starch is hydrolyzed by amylase

Question 16

How do you make High fructose Corn syrup?

Answer 16

Hydrolyze maltose by maltase into glucose, which is then isomerased by glucose isomerase

Question 17

What is the difference between invert sugar and HFCS?

Answer 17

Invert sugar has a 1:1 ration of fructose and glucose and is made by hydrolyzing sucrose with invertase or an acid

Question 18

Which sugar is not reducing?

Answer 18

Sucrose (no free OH)

Question 19

Name the non enzymatic browning reactions

Answer 19

caramelization and Maillard browning

Question 20

What is caramelization?

Answer 20

Sugars are heated at high temperatures

Question 21

What is Maillard browning?

Answer 21

Reducing sugar react with nitrogenous compounds. Responsible for the browning on toast

Question 22

What is gelatinization?

Answer 22

Heating up starch granules in water, thee starch granules absorb water, swell and burst

Question 23

What is retrogradation?

Answer 23

The reverse of gelatinization - yet cannot reform granules. This can be partially reversed by heating

Question 24

Calories in fats?

Answer 24

9 cal/g

Question 25

What is an unsaturated fat?

Answer 25

Contain double bonds

Question 26

What is a saturated fat?

Answer 26

Contains only single bonds

Question 27

What are the characteristics of animal fats?

Answer 27

Solid at room temperature, saturated, high melting point, fatty acids packed more tightly

Question 28

What are the characteristics of vegetable oils?

Answer 28

Liquid at room temperature, unsaturated, packed less tightly, lower melting point than animal fats, less stable

Question 29

What is the difference in trans and cis unsaturated fatty acids?

Answer 29

Trans fatty acids have a higher melting point since its packed more tightly

Question 30

What are the types of rancidity?

Answer 30

Oxidative and hydrolytic

Question 31

What is oxidative rancidity?

Answer 31

Cause off flavours and carcinogenic compounds

Question 32

What happens when monounsaturated FA and polyunsaturated FAs are exposed to heat, light and O2?

Answer 32

hydroperoxides can form

Question 33

What is hydrolytic rancidity?

Answer 33

Bonds between glycerol and the FAs are cleaved by lipase, forming free FAs, which is odorous

Question 34

How do you decrease the rate of oxidative rancidity?

Answer 34

Store away from light, O2 and warmth, avoid repeated exposure to high temperatures, add antioxidants, hydrogenation

Question 35

What is hydrogenation?

Answer 35

Hardening liquid oils by forcing h atoms into double bonds in the trans configuration

Question 36

What is the problem with trans fats?

Answer 36

although they behave like saturated fats, LDL cholesterol is increased which increases heart disease. Amount of TF must be labelled

Question 37

What does lecithin do?

Answer 37

Decrease interfacial tension by forming an emulsion

Question 38

What do stabilizers do?

Answer 38

Increase viscosity of the continuous phase

Question 39

What are the calories of proteins?

Answer 39

4 cal/g

Question 40

What causes allergies?

Answer 40

Intolerance to certain proteins, indigestibility

Question 41

What is free water?

Answer 41

Water in tissue food systems an in dispersion, available to microorganisms, can be bound by salt and sugar

Question 42

What is bound water?

Answer 42

Not readily available

Question 43

What does an Aw of 1 mean?

Answer 43

All water is free

Question 44

What do organic acids do?

Answer 44

Impart flavour and acidity

Question 45

What is a low acid food?

Answer 45

pH above 4.6

Question 46

What is an acid food?

Answer 46

pH below 4.6, does not support disease causing microorganism growth

Question 47

What makes flavour?

Answer 47

Aroma (volatile) and taste (non volatile)