CHAP 5 : Forumlated foods Flashcards
What are formulated foods?
Why are most formulated foods preserved?
- 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
What are the benefits of formulated foods? (4)
- Shelf stable, safe, and convenient
- Trade-offs between nutrition and quality are not as significant in formulated foods as in processed foods
- Safer than processed foods as they contain preservatives
- Fit in nicely with our fast-paced culture tend to be ready to eat or require minimal preparation
What are the disadvantages of formulated foods?
- When consumed in excess, it can be detrimental to our health and decrease our desire to eat more nutrient-dense foods.
- Formulated foods that contain fruits and vegetables may convey the false idea that they provide benefits of whole fruits and vegetables.
- Unhealthy, high in salt, sugar or fat
Formulation of food products : What are unit operations? Examples of common unit operations?
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
Types of food ingredients
(not in lect notes)
What is the function of flours and grains? [2]
- to provide calories
- providing basic structure and texture of a product
What is gluten? What functions does it serve?
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.
How does gluten contribute to the texture of foods such as bread?
https://www.youtube.com/watch?v=zDEcvSc2UKA
CO2 gas bubbles produced by yeast / baking powder are trapped in pockets formed by the gluten network, creates light, fluffy texture of bread
Why is fiber often removed from foods despite its nutritional value? [2]
- To improve the functionality of the ingredient
- Increase appeal to its customer
How can fruits and vegetables be processed? [4]
Preserved w sugar, canned, frozen or dried.
What are the functions of fruits and vegetables? [2]
- Add colour and texture to products
- Providing nutrition and flavour
What is the function of dairy and eggs?
Sources of high-quality protein and calcium
What are the main protein fractions in milk and what is their main function?
- 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.
Where are gels formed from? What are their functions?
- 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)
What is the function of egg yolk?
It acts as an emulsifier, preventing water and fat from separating in products like mayonnaise.
What is the function of egg yolk?
It acts as an emulsifier, preventing water and fat from separating in products like mayonnaise.
What is the function of egg white?
It has the ability to foam → providing light, fluffy texture of cakes, meringues etc.
What are examples of some sources of plant proteins?
Grains (corn and oats) and oil-rich seeds (peanuts, soy beans)
Plant proteins are not complementary proteins and must be balanced from proteins from another source, like beans. True or False?
True
For use as ingredients, plant proteins do not need isolated and purified. True or False?
False
What is the physical state of fats and oils at room temperature?
Fats : solid at rtp, oils : liquid at rtp
What are the functions of fat and oils? [4]
- Increase satiety –> slows stomach-emptying time
- Acts as carrier of flavour, contribute to mouthfeel
- Act as lubricants in the mouth
- 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
What are the functions of sweeteners? [3]
- Contribute to colour and texture of food products.
- Provide bulk and contribute to mouthfeel
- Have other functional properties relating to sponginess of cakes and creaminess of ice cream
What is the advantage of using artificial sweeteners over natural ones?
Major reduction in calories
What are problems associated with artificial sweeteners and how can they be overcome?
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
Why do some artifical sweeteners require bulking agents?
To provide texture and volume of missing sugar
What are the disadvantages / problems with fat replacers? [3]
- Flavour and mouthfeel of fat is very difficult to replace
- Fat replacers are not stable to high-temperature frying and cooking unlike fats
- Olestra, a fat replacer, though thermally stable, cannot be digested and absorbed by body
What are examples of fat replacers? What is their main function?
- examples : gums and hydrocolloids (carbohydrates similar to dietary fibre)
- provide similar texture to foods and replace bulk of the fat.
What are examples of fat replacers? What is their main function?
- examples : gums and hydrocolloids (carbohydrates similar to dietary fibre)
- provide similar texture to foods and replace bulk of the fat.
What are problems with completely removing fat from a food product? [2]
- 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
Flavour ingredients are volatile compounds contributing to aroma of foods. True or false?
True
Where can natural colourants be isolated from? (i.e. sources of natural colourants)
fruits, vegetables, flowers or insects
What are the benefits of using artificial colourants over natural ones? [3]
artificial colourants are brighter, more stable and easier to handle than natural colourants.
What are the functions of colourants and flavourants? [3]
- Enhance flavour and colour → though most flavour ingredients are colourless, colour can influence the perception of flavour
- 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
- Artificial colours to enhance appeal of food products
What is the function of stabilisers?
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)
What are the 2 important groups of stabilisers? What are their characteristics and their functions if any ?
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
What are the functions of preservatives? Give examples of preservatives for each function[3]
- Slow or prevent spoilage (microbial growth) – e.g. Nitrites, nitrates
- Prevent fatty foods and oils from developing rancidity – e.g. Natural antioxidants like vitamins A,C and E ; Synthetic antioxidants like BHA
- Add flavour , slow the growth of moulds, act as antioxidants – e.g. Spices
