NUFS 100 Topic 4 Food Processing

mold foody, yum

fermentation

acid is produced, ph is reduced, bacteria is controlled

what does it mean to be a geological food

some foods are only made in certain country - France makes Roquefort cheese

pan-continental food

made in every sections of the world - bread, beer, vegetable

what is the fermentation process

nutrients in food

metabolised

fermentation produces accumulate

interaction of fermentation produces with food components

change in food character

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what can you make with lactic acid

pickles, sour cream, salami

what can you make with yeast

bread, bread,

what can you make with molds

cheese

what acid do you make swiss cheese with

propionic acid

what acid do you make coffee and chocolate with

acetic acid

what do you make with acetic acid

vinegar, coffee, chocolate

naturally, wild or spontaneous source of fermerntation

used at home

microbe is natural in foods - cabbage, bread

starter cultures

wine, beer, dairy, meet

used in the industry

result in a consistent product

control microbial growth

true or false:

dry bacteria grows by its self

false

it needs water to grow

drops in ph means _____ pathogens

less

what does salt do

release tings in brine

probiotics

live bacteria that help digestive health

prebiotics

indigestible carbs aka food for probiotics

gut microbiome

population of bacteria in the intestine

health outcomes of keeping gut microboime healthy

mental health

sleep physiology

heart health

weight monitoring

what yogurt company has probiotics and says to eat 2 a day?

activia

true or false:

only fermented things carry probiotics

false

not everything that carries probiotics are fermented

food preservation goals

minimize spoilage

maximize safety

maintain nutritional value

food formulation

list of ingredients

process flow diargram

steps in the processing system

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unit operations

each step in the process flow diagram - chopping, washing etc

examples of unit operations

material handling

disintegrating (chopping)

heat exchange

separating

pumping

evaporation

cleaning

mixing

value added

value of labour when producing products

what are the 3 principle preservations

low temp - freeze/refrigeration

drying

thermal processing - canning/pasteurization

aproach

change environment or destroy microbes

drying

water removal

freezing

water is unavailable

refrigeration

low temp

heat sterilization

viable microbes are inactivated

heating - baking, pasteurization

inactivation of microbes

fermentation

acid producing microbes, lower ph level

pickling/salting

adding salt or sugar to soak up water

what keeps bread form molding

sodium benzoate

how do you control the atmosphere

remove oxygen

add or remove nitrogen

add or remove carbon dioxide

what do wax linings do to oxygen

inhibit it

what is the danger zone

4-60c

what temperature should a fridge be at

0-5c

what temperature should a freezer be at

0 - -18c

refrideration

good for long or short term

before fridges there were lots of salted and canned items

when was the first ammonia fridge invented

1875

what were ice boxes lined with

zinc

when were ice boxes used

1800s

how does refrigeration work

when a liquid evaporates it absorbs heat

when vapour condenses it releases heat

so, refrigerant evaporates in the fridge to make a cool environment

what is a common refrigerant

hydrofluorocarbons (HFCs)

gentle preservation

doesn’t effect the taste, texture, or nutritional value

why should things be cooled down quickly after harvest/butcher

living things give off heat and they were just alive aka field heat

what should fridge humidity be

80-95%

challenges with refridgeration

cross-contamination

spoilage overtime - especially if humidity and temp aren’t right

odours transfer from food to food easily

temperature

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freezing

water changes to ice crystals

is a unit operation

temperature is lower than the food’s freezing point

allows fresh things to last a whole year

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clarence birdseye

father of frozen food

opened first freezing plant in 1920s

frozen food prices go up ___% per year

4

why do frozen food prices go up at a steady rate

increased plant food consumption

convenience

new product offerings

smaller packaging

how did frozen food sales fare during the pandemic

demand and consumption sky rocketed

does freezing inhibit or destroy microbial growth

inhibit

dissolving substances in aqueous phase ____ freezing point

lowers

freezing point of fresh meat

\-1.5c

freezing point of fresh vegetables

\-1c

freezing point of fluid milk

\-0.5c

freezing point of icecream

\-6.0c

things expand in the freezer due to ____ freezing

slow

ice is __x the size of water

1\.09

variation of temperature causes different _____ sizes

ice crystal

which size of ice crystal is better, and why

small, doesn’t puncture cell walls and things

challenges with freezing

fluctuation in temp

freezer burn - moisture loss

chemical changes - blanching veggie > fruits

rancidity - odd flavours, mostly meats

freeze concentration - solutes are left behind after water moves out (freezes)

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how to get small ice crystals

rapid freezing

blast freezing

pushing cold air at high velocity across a food fast

batch blast freezer

food is on trays and have to be swaped out

spiral freezer

food is on a conveyer belt and is continuously moving

fluidized bed freezer

refrigerated air is forced under a perforated tray, lifts up and spins the objects.

why is fluidized bed freezer superiour

it is a quick freeze where everything is individually frozen with little dehydration

when forzen in the fluidized bed freezer food is frozen ____ and not in …

individually, blocks

IQF

Individually Quick Frozen

contact plate

after food is loaded onto the trays they are pressed and refrigerant circulates through the plates freezing the food

contact plates are used for ___

flat foods or brick shaped products

cryogenic freezing

frozen quickly - nitrogen icecream

usual foods - seafood

fresh food can spend 2____ from harvest until consumption

weeks

when are frozen products processed

the same day as harvest

does fresh or frozen have more nutrients

frozen

processed day of harvest

advantages of dehydration and concentration

reduction of moisture content and water activity

reduction of product weight and volume - transportation cost and reduced packaging

Dehydration

longer shelf life

remove water so microbes can’t grow

examples of dehydration

jerky, fruit leather, powdered eggs

sun drying

poor completeness

slow

low cost

poor uniformity

challenges with sun drying

mold

incompleteness

pests

slow

case hardening

when the outside layer of a food dry’s quicker than the inside so the moisture is locked in and can’t leave

how to prevent case hardening

cut into smaller pieces, make more surface area

sun opperation

radiant heat evaporates water

hot air operation

closed environment, hot air by convection

spray operation

fluid foods are sprayed into stream of hot air

fluidized bed operation

beds of food are lifted into the air

spray

creates powdered foods

starts with concentrate

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under high pressure, there is a ______ boiling point

higher

under low pressure there is a ____ boiling pint

lower

vacuum chambers use ____ pressure

low

vacuum drying

removes water at a low temp

high pressure can ___ nutrients

break/lose

freeze drying

evaporates moisture during sublimation

food is frozen and then put into a vacuum chamber