Food Deterioration

How long do leafy vegetables last at room temp (70 degrees)?

1-2 days

How long do fruits last at room temp (70 degrees)?

1-7 days

what percentage of air does oxygen make up?

10%

what temp range is most bacteria killed in

180-200 degrees

how long do rats live

2-3 years

what is temp of sterilization for acidic foods

200 degrees

in 24 hours at room temp what is the bacteria count in milk?

25 million

how many litters can rats have per year

3-5

underfavorable conditions, how long does it take bacteria to double its numbers?

30 minutes

How long does dried, smoked meat last at room temp?

360+ days

How long to dried seeds last at room temp?

360+ days

how much do insects destroy in field and storage of UD grain crop?

5-10%

what is normal harvest temp

50-100 degrees

what temp range is most food handled in

50-100 degrees

How long do root vegetables last at room temp?

7-20 days

how many young do rats have per litter

7-8

what percentage of air does nitrogen make up?

70%

how much excess water may be contained in microorganisms in healthy state?

80%

what kinds of diseases do rodent excretion spread?

Salmonellosis, typhus fever, plague

food deterioration

a series of continuous degradative changes occurring in a food item which may effect the product's wholesomeness and result in a reduction of its quality and/or its serviceability

activity of food enzymes

at the time of harvest or slaughter, enzymes that control digestion and respiration proceed uncontrolled and cause the tissue damage (e.x. fermentation good, rancidity bad)

thermophilic

bacteria grow as high as 180 degrees

psychrophilic

bacteria grow down to freezing point

what causes oxidative rancidity

bacteria or enzymes

bacterias, yeasts and molds - how do they compare in size?

bacteria smallest, then yeast, then mold

when do most bacteria multiply

between 60 and 100 degrees F (mesophilic)

what happens when freezing milk

breaks down fat emulsion, can denature milk protein (curdling)

facultative

can grow in aerobic or anaerobic conditions

obligative

capable of surviving and aerobic OR anaerobic situation

physical changes

caused by low or high temps, the gain or loss of moisture, physical stress or abuse, light, industrial contaminants (e.x. bananas brown in fridge)

surface moisture caused by

changes in relative humidity can cause lumping and caking, as well as surface defects such as mottling, crystallization, stickiness

what kinds of acids are added to foods

citric acid, phosphoric acid

3 classifications of bacteria

cocci - spherical shapes bacilli - rod shape spirilla and vibrios - spiral forms

4 types of dates

date of manufacture (pack date) date by which product should be sold (sell by date) last date of maximum quality (best used by date) date beyond which product is no longer acceptable (use by date or expiration date)

what can radiation do

destroy microorganisms and inactivate enzymes

insects

destructive to cereal grains, and fruits and vegetables; eggs may persist after processing (like in flour); chemicals used in control

what happens to frozen fruit

discoloration, changes in texture, cracked skins, and is not susceptible to microorganisms

EPA

environmental protection agency

True or False: irradiation is not considered a food additive and so not monitored by FDA

false

trichinosis nematode

foodborne parasite entering hogs eating uncooked food wastes

wholesomeness

free from pathogenic or otherwise harmful organisms; a characteristic possessed by a food product that is conducive to good health and well being in the customer

microorganisms

growth and bacteria of microorganisms, particularly bacteria, molds, and yeasts (e.x. acid, gas, toxins)

What kind of deterioration progress with time?

growth of microorganisms loss of flavor destruction by insects effects of heat/cold moisture oxygen light

how are enzymes inactivated?

heat, chemicals, radiation

Most important means of controlling bacteria, yeasts, molds:

heat, cold, drying, acid, sugar, salt, smoke, air, chemicals, irradiation

When is deterioration time slower?

high in sugar, salt, or acid

organoleptic

how something is perceived by sensory organs

for ever rise in 50 degrees, what happens to the rate of chemical reaction

it doubles

after how long are some fruits, leafy vegatables, and raw milk inedible at room temp?

less than 24 hours

after how long is meat, fish, and poultry inedible at room temp?

less than 24 hours

who defines minimum acceptability quality (MAQ)

manufacturer

major causes of food deterioration

microorganisms activity of food enzymes chemical reactions physical changes time insects and/or rodents

Which spores are most resiliant?

molds

condensation can come from

outside or moisture barrier packaged fruit and vegetables that give off moisture from respiration and transpiration

in 96 hours at room temp what is the bacteria count in milk?

over 5 billion

chemical reactions

oxidation, color changes, reactions between a food container and its contents and coagulation of proteins

Shelf life will vary due to

processing method, packaging, and storage conditions

rodents

qty of food they consume and filth (urine, feces) that they contaminate foods

What is the major strategy in reducing food spoilage?

reduce contamination by ensuring good sanitation practicies

quality

refers to the degree of excellence or grade of a product

What vitamins does light especially destroy?

riboflavin, vit a, vit c

How many bacterias, yeasts, and molds are associated with foods?

several hundred

what microorganisms are anaerobic

some bacteria

Which microorganisms are aerobic

some bacteria and all molds

What produces spores

some bacteria, yesast, and all molds

what ensures sterility

temp of 250 degrees for 15 minutes or longer

What kind of sugar solutions have high osmotic pressure and low water activity?

those high in solute

shelf life

time it takes a product to decline to an unacceptable level; tie product remains salable

how does oxidative rancidity affect meat color

turns it brown

how does oxidative rancidity affect fat color

turns it yellow

scorbic acid

used to treat the surface of cheese to prevent mold growth

serviceability

usefulness of a food item

mesophilic

whem bacteria multiply between 60 and 100 degrees F

chill injury

when held at 40 degrees and are deteriorated

Microorganisms and tolerance?

yeasts and molds more than bacteria