CHAP 5 : Forumlated foods

Question 1

What are formulated foods?
Why are most formulated foods preserved?

Answer 1

• Formulated foods are products that are mixtures of ingredients, and are not directly recognizable as their original plant or animal sources.
• Most formulated foods are preserved to reduce microbial load

Question 2

What are the benefits of formulated foods? (4)

Answer 2

1. Shelf stable, safe, and convenient
2. Trade-offs between nutrition and quality are not as significant in formulated foods as in processed foods
3. Safer than processed foods as they contain preservatives
4. Fit in nicely with our fast-paced culture tend to be ready to eat or require minimal preparation

Question 3

What are the disadvantages of formulated foods?

Answer 3

1. When consumed in excess, it can be detrimental to our health and decrease our desire to eat more nutrient-dense foods.
2. Formulated foods that contain fruits and vegetables may convey the false idea that they provide benefits of whole fruits and vegetables.
3. Unhealthy, high in salt, sugar or fat

Question 4

Formulation of food products : What are unit operations? Examples of common unit operations?

Answer 4

Unit operations : physical processes used to separate, transform or transport materials in a process system

materials handling, pumping, mixing, heat exchanging, packaging, drying, controlling etc

Question 5

Types of food ingredients
(not in lect notes)

What is the function of flours and grains? [2]

Answer 5

1. to provide calories
2. providing basic structure and texture of a product

Question 6

What is gluten? What functions does it serve?

Answer 6

Gluten is a protein naturally found in some grains including wheat, barley, and rye.

It acts like a binder, holding food together. It is elastic thus allowing it to bend, expand and stretch rather than break.

Question 7

How does gluten contribute to the texture of foods such as bread?

https://www.youtube.com/watch?v=zDEcvSc2UKA

Answer 7

CO2 gas bubbles produced by yeast / baking powder are trapped in pockets formed by the gluten network, creates light, fluffy texture of bread

Question 8

Why is fiber often removed from foods despite its nutritional value? [2]

Answer 8

1. To improve the functionality of the ingredient
2. Increase appeal to its customer

Question 9

How can fruits and vegetables be processed? [4]

Answer 9

Preserved w sugar, canned, frozen or dried.

Question 10

What are the functions of fruits and vegetables? [2]

Answer 10

1. Add colour and texture to products
2. Providing nutrition and flavour

Question 11

What is the function of dairy and eggs?

Answer 11

Sources of high-quality protein and calcium

Question 12

What are the main protein fractions in milk and what is their main function?

Answer 12

• Casein and whey
• They coagulate and come out of solution to form smooth and creamy texture of yoghurt, sour cream etc
• Proteins can act as emulsifiers. During homogenisation of milk, fat globules decrease in size and caesin protein is partially unfolded, allowing it to bind to fat globules to form an emulsion.

Question 13

Where are gels formed from? What are their functions?

Answer 13

• Can be formed from egg white, milk and certain plant and animal proteins
• Gels bind water, providing customer with unique textural sensations (formation of such gels is used in molecular gastronomy)

Question 14

What is the function of egg yolk?

Answer 14

It acts as an emulsifier, preventing water and fat from separating in products like mayonnaise.

Question 14

What is the function of egg yolk?

Answer 14

It acts as an emulsifier, preventing water and fat from separating in products like mayonnaise.

Question 15

What is the function of egg white?

Answer 15

It has the ability to foam → providing light, fluffy texture of cakes, meringues etc.

Question 16

What are examples of some sources of plant proteins?

Answer 16

Grains (corn and oats) and oil-rich seeds (peanuts, soy beans)

Question 17

Plant proteins are not complementary proteins and must be balanced from proteins from another source, like beans. True or False?

Answer 17

True

Question 18

For use as ingredients, plant proteins do not need isolated and purified. True or False?

Answer 18

False

Question 19

What is the physical state of fats and oils at room temperature?

Answer 19

Fats : solid at rtp, oils : liquid at rtp

Question 20

What are the functions of fat and oils? [4]

Answer 20

1. Increase satiety –> slows stomach-emptying time
2. Acts as carrier of flavour, contribute to mouthfeel
3. Act as lubricants in the mouth
4. Can serve as flavour precursors / become oxidised

Precursor : flavourless compound that changes form to either a desirable or undesirable flavour during mixing, heating or storage

Question 21

What are the functions of sweeteners? [3]

Answer 21

1. Contribute to colour and texture of food products.
2. Provide bulk and contribute to mouthfeel
3. Have other functional properties relating to sponginess of cakes and creaminess of ice cream

Question 22

What is the advantage of using artificial sweeteners over natural ones?

Answer 22

Major reduction in calories

Question 23

What are problems associated with artificial sweeteners and how can they be overcome?

Answer 23

ome artificial sweeteners have a bitter aftertaste, cause gassiness (farting, aka flatulence) or only work well in certain types of food (baked goods)

Problem can be overcome by mixing artificial sweeteners

Question 24

Why do some artifical sweeteners require bulking agents?

Answer 24

To provide texture and volume of missing sugar

Question 25

What are the disadvantages / problems with fat replacers? [3]

Answer 25

1. Flavour and mouthfeel of fat is very difficult to replace
2. Fat replacers are not stable to high-temperature frying and cooking unlike fats
3. Olestra, a fat replacer, though thermally stable, cannot be digested and absorbed by body

Question 26

What are examples of fat replacers? What is their main function?

Answer 26

• examples : gums and hydrocolloids (carbohydrates similar to dietary fibre)
• provide similar texture to foods and replace bulk of the fat.

Question 26

What are examples of fat replacers? What is their main function?

Answer 26

• examples : gums and hydrocolloids (carbohydrates similar to dietary fibre)
• provide similar texture to foods and replace bulk of the fat.

Question 27

What are problems with completely removing fat from a food product? [2]

Answer 27

1. difficult to match flavour and texture of the full fat product

2.Consumers may eat more low fat product to fill themselves up and not reduce their calorie intake

Question 28

Flavour ingredients are volatile compounds contributing to aroma of foods. True or false?

Answer 28

True

Question 29

Where can natural colourants be isolated from? (i.e. sources of natural colourants)

Answer 29

fruits, vegetables, flowers or insects

Question 30

What are the benefits of using artificial colourants over natural ones? [3]

Answer 30

artificial colourants are brighter, more stable and easier to handle than natural colourants.

Question 31

What are the functions of colourants and flavourants? [3]

Answer 31

1. Enhance flavour and colour → though most flavour ingredients are colourless, colour can influence the perception of flavour
2. Flavourants may provide or add to the flavour impact of a product, enhance or mask other flavours, or provide a background for other flavours present
3. Artificial colours to enhance appeal of food products

Question 32

What is the function of stabilisers?

Answer 32

Prevent separation (breakdown) of food components in formulated foods not related to microbes and maintain product structure (e.g. separation of oil from peanut butter)

Question 33

What are the 2 important groups of stabilisers? What are their characteristics and their functions if any ?

Answer 33

Emulsifiers and gums.

Emulsifiers : can both disperse in water and oil

Gums : water soluble polysaccharides (starch, glycogen)

• Function : help thicken liquid and semi-solid foods.
  Thicken up by binding water present and swelling up

Question 34

What are the functions of preservatives? Give examples of preservatives for each function[3]

Answer 34

1. Slow or prevent spoilage (microbial growth) – e.g. Nitrites, nitrates
2. Prevent fatty foods and oils from developing rancidity – e.g. Natural antioxidants like vitamins A,C and E ; Synthetic antioxidants like BHA
3. Add flavour , slow the growth of moulds, act as antioxidants – e.g. Spices