FOOD PRESERVATION 1

Question 1

what’s the goal of food preservation

Answer 1

extend shellfire to allow storage and convenient distribution

Question 2

whats the most dangerous limitation to food preservation

Answer 2

microorganisms

Question 3

whats the primary aim of food preservation

Answer 3

eliminate microbial spoilage by limiting available water

Question 4

what are some physical methods of food preservation

Answer 4

concentration, dehydration, freezing

Question 5

what are some chemical methods of food preservation

Answer 5

addition of solutes (sugars, salts)

Question 6

what changes contribute to food spoilage

Answer 6

biological, chemical, physic

Question 7

what are three causes of biological spoilage

Answer 7

bacteria, yeasts, molds

Question 8

what foods are susceptible to bacteria spoilage + how to prevent?

Answer 8

high water activity + high protein
can control by keeping water activity low

Question 9

what is yeast attracted to

Answer 9

liquid foods high in sugar (fruits + preserves)

Question 10

what does yeast caused + how can you prevent

Answer 10

can cause unwanted fermentation + can control by keeping water activity low

Question 11

what will mold grow on

Answer 11

almost any foods under suitable conditions of moisture, air and temp

Question 12

how to control mold?

Answer 12

can control by keeping oxygen levels low (vacuum)

Question 13

describe enzymatic spoilage

Answer 13

chemical changes due to enzymes; proteins that catalyze chemical reactions

Question 14

describe proteases

Answer 14

spilt proteins into smaller peptide and polypeptide fragments

Question 15

what do good proteases do

Answer 15

create food flavor and vice versa

Question 16

what do lipases do

Answer 16

contribute to enzymatic spoilage; break down lipid (triglycerides) into glycerol and fatty acids

Question 17

what does further enzymatic/lipid degradation lead to

Answer 17

rancidity (off odors/ taste) due to reaction with oxygen or water

Question 18

what do carbohydrates do

Answer 18

breakdown carbohydrates (typically named after carb they act on)

Question 19

whats an example of a carbohydrase

Answer 19

amylase

Question 20

whats polyphenol oxidase

Answer 20

undesirable browning of fruits and vegetables; enzymatic spolage

Question 21

what is physical spoilage due to

Answer 21

water migration

Question 22

name two types of physical spoilage

Answer 22

evaporation + seperatiion

Question 23

describe evaporation

Answer 23

water loss due to improper storage + undesirable dried out appearance

Question 24

describe seperation

Answer 24

water + oil separation; unlike chemical changes, dont result in formation of new compounds

Question 25

what is the most important thing to control in food preservation

Answer 25

water

Question 26

whats drying + name five types

Answer 26

removal of water sun-drying; conventional; vacuum; osmotic; freeze-drying

Question 27

what does drying do

Answer 27

inhibits growth of microorganisms

Question 28

whats sun-drying

Answer 28

sun provides heat to evaporate water (ex: tomatoes)

Question 29

whats conventional drying

Answer 29

uses heat to evaporate water; tray, tunnel, drum, spray-drying, big oven (ex: whey)

Question 30

whats vacuum-drying

Answer 30

pressure is lowered below atmospheric, which lowers boiling point of water (ex: tomato paste)

Question 31

whats osmotic drying

Answer 31

uses concentrated syrup to osmotically draw out water (craisins)

Question 32

whats freeze-drying

Answer 32

frozen solid water is sublimated (solid to gas) at low pressure and temp (ex: instant coffee)

Question 33

whats curing

Answer 33

high concentrations of solutes (salts, nitrates, nitrites, sugars, etc) draw water out of food, making it unavailable to microorganisms

Question 34

describe smoking cured meats

Answer 34

meats exposed to smoke of burning wood for added flavor (flavor depends on type of wood)

Question 35

whats fermentation

Answer 35

microorganisms convert sugar -> alcohol, gases, acids

Question 36

describe why fermentation works

Answer 36

most spoilage microorganisms cannot survive in acidic or alcoholic environment