MCB master race

Robert Hooke and Anton von Leeuwenhoek

two people that observed microscopic fungi and bacteria

Lazzaro Spallanzani

Boiled meat strike a blow on spontaneous generation

Nicolas Appert

discovering panning during napoleon

Peter Durand

Patents tin can

Appert and Raymond Chevallier-Appert

Retort

Louis Pasteur

discovered living organisms that cause lactic and alcoholic fermentation, disproved spontaneous generation; joseph lister develops the concept of antiseptic process

Robert Koch

postulate bacteria as causative agents of disease

Hans Christian Gram

Gram stain

Julius Richard Petri

invented the petri dish

Joseph Lister

father of antispetic techniques

A.A. Gartner

Isolates Salmonella enterica serovar enteritidis

1890

when did milk get pasteurized

1900

Food and drug act passed in this century

Alexander fleming

discovered antibiotics

Clarence Birdseye

introduced frozen foods commercially

GM Dack

confirms the staphylococcus aureus produces toxins

James Watson and Francis Crick

discover the DNA structure research on food irradiation

C. Duncan and D. Strong

discovered that poisoning is caused by toxins

Fungal toxins

elucidated in turkey x disease

Molds, Yeast, Bacteria

rank these organisms by pH survivability range: Bacteria molds yeast

acidic.

when animals die, 1% glycogen converts to lactic acid and the internal pH becomes more _____

Inherent acidity

Fermented milks, sauerkraut, and pickles, mustard. Fruit are all examples of foods that have __________

Buffering capacity

ability of certain foods to resist drastic changes in pH. An example component of these foods is protein. This macromolecule increases this characteristic of some foods.

charged = uncharged, protonated acids are most common and can cross the cell membrane

why is pKa of acids so important in pH and food preservation. And why is it better for ph to be near or lower than pka

Stops nutrient transport, membranes are denatured, stops function of enzymes

how does pH parameter effect the cells

Energy is used to expel acids within the cell membrane,

why is pH a good parameter for inhibition

8-9

upper limit for basic pH

Homeostatic response

happens in pH 6.0, Increases the activity of proton pumps in order to expel more protons from the cytoplasm. This ph adaptive response is always on

Acid Tolerance Response

happens pH 5.5 to 6.0, sensitive to protein synthesis inhibitors. Involves the ATPase proton pump to maintain a pH of 5.0

Synthesis of Acid Shock Proteins

happens pH 3.0 to 5.0, Constitutes a set of regulatory proteins distinct from the atr proteins

moles, vapor pressure, equilibrium relative humidity

three types to express water activity

no, Aw is the amount of usable water

is Aw and amount of water the same?

salts/ sugars

how to lower Aw using solutes

Freezing, dehydration, evaporation, freeze drying

lowering Aw using external conditions

Oxidation-reduction potential

ease of which the substrates losses or gains electrons

Aerobic microorganisms

what type of microbes grow within ranges of +500mv to +300mv, oxidized environments, and positive redox potential?

Anaerobic Microorganisms

what type of microbes grow within ranges of +100mv, -250mv

Poisoning capacity

refers to the term of foods to resist drastic changes in Eh

depletion of O2 in the environment results to alternate and not as efficient means of e-acceptor

describe the effects of redox potential of microbes

SH groups and ascorbic acid

amino groups that maintain reducing conditions in foods

Microaerophiles

slightly reduced conditions bacteria, lactobacilli and campylobacters

Facultative anaerobes

aerobic/ anaerobic. Most yeast and Molds

meats more oxidized, vegs more reduced

compare the redox of meats and vegetables

carbs, fats, simple sugars

energy sources

Amino acids , proteins

nitrogen source

Gram-positive bacteria

what are the microorganisms that cannot synthesize b-vitamins on their own

Gram-negative and molds

what are microorganisms that can synthesize their own b-vitamins

lower in B-vitamins

why are meats more susceptible to mold spoilage than negative gram spoilage?

oils (eugenol, allicin, cinnamic)

antimicrobial constituents of plants

lactoferrin, conglutinin, lactoperoxidase system, casein

antimicrobial constituents of cow’s milk

isothiocyanates

antimicrobial constituents when damaged in cruciferous plants

lysozyme conalbumin avidin

eggs microbial constituents

lactoperoxidase, thiocyanate and H2O2

components of lactoperoxidase system

lactoperoxidase system

inhibitory system that occurs naturally in bovine milk

gram negative

microbes that are sensitive to lactoperoxidase system

covering, testam, shells, hides

biological structures parameters

slower and genetically different

Factors that are effected due to low temp

Psychrotrophs

below 7C and optima, 20-30C

Mesophiles

20-45 survivability, 30-40C optimal

Thermophiles

45, optimal 55-65C

Compatible solutes, cold shock proteins, Homeoviscous adaptation

synthesis of increasing amounts of mono= and Di unsaturated fatty acids

kinks

what are produced in the dna to stop the tight packing of fatty acids and solidification

below 40/ above 140

golden rule for temperature

thermotolerance

sublethal temperature can increase _______

Cold shock proteins

RNA chaperons, minimizing folding of RNA

food looses moisture in low RH, resulting in less Aw

why is low RH better?

CO2, O2, Ozone

gasses used to control gas composition of foods

strong oxidizing agent

why is ozone not good with high lipid foods

extend lag phase, slow growth rate, increase death rate

describe hurdle technology in terms of lag phase, growth rate, death rate

Homeostasis

tendancy of microogansims to maintain their internal statues, hurdle tech either disturbs temporarily/permanently alter the internal conditions of the organism

Metabolic exhaustion

mircrobes attempt to stabilize themseleves cause metabolic energy

Stress reaction

stress shock proteins, acid tolerance response proteins