Food Microorganisms, Toxins, and Food Safety: Key Concepts and Examples

what are the four types of foodborne microrganisms

mold, bacteria, parasite, virus

example of mold

Aspergillus

Example of bacteria

Salmonella

example of parasite

tapeworm

Example of virus

HIV

infection

invasion of the body by a pathogenic organism

Intoxication

The germs grow in the food before you eat it and make toxins (poisons).
When you eat the food, those toxins make you sick.

Toxico-infection

organism causes illness by producing toxin while growing in the intestine

example of infection

Salmonella

Example of intoxication

Botulism

example of toxcio-infection

Clostridium perfringens

what are factors that promote microbial growth

aw over 0.91, temp 40-140, near netural ph

what is the primary source of s.aurus contaimation

human and its caused by intoxication

different stages of the bacterial growth cycle

lag,log,stationary and death

What are pigments?

Colored chemical compounds that absorb light

example of plant pigments

Chlorophyll

Do anthocyanins change color under different pH conditions?

yes

which pigments are responsible for red to brown colors in meats how do they change color

myoglobin to metmyoglobin, making it brown.

provide some examples of ingrdents that affect food texture

aw, fat content,strach and gums

difference between pasturization commerical and strerlization

Pasteurization: Kills most germs — not all.

Commercial sterilization: Kills almost all germs so food is safe at room temperature.

Sterilization: Kills all germs and spores — completely germ-free.

which microrgamism is considered as the largest pathogen when we do thermal processing of food why?

clostridum botiumum

How to find D value

D-value = how long it takes to kill 1 log (or 90%) of bacteria at a certain temperature.

what are some charaistics of aspic packaging

food heated/sterlized before packaging most suitable for liquid foods

advantages of non-thermal processijg

retain color texture taste and flavor

what are some types of nonthermal processing

hpp,pef,omf

what is the mecanism of inactivation for high pressure processing what are the crinical process parameters in hpp

HPP kills microbes by breaking their cells and proteins using very high pressure.Its main control factors are pressure, time, and temperature.

Are HPP-treated products widely accepted?

yes

how does pef inactviate microrganisms

It works by making holes in the cell membrane (electroporation), causing the cells to leak and die — all without using heat.

what is drying what happends during drying

Drying removes moisture from food, causing water to evaporate and making the food last longer.

what are the advantages of spray drying

Advantages of Spray Drying:

Fast drying — water evaporates very quickly.

Preserves flavor, color, and nutrients because drying happens quickly.

Does freezing kill microbes?

no, it's not effective at killing microbes; preserves food

at what temp is there no spoilage

over -9.5 celcious

what are some key requirmenfrs of an effective refrigated storage

In short:

Keep it cold, clean, and well-ventilated with proper humidity and organization for safe refrigerated storage.

what are the changes that occur in foods during freezing

In short:

During freezing, water becomes ice, which can change texture, flavor, color, and nutrients if not stored properly.

how does freezinf affect these changes

Freezing helps preserve food by stopping spoilage and slowing changes, but fast freezing and good packaging are important to protect texture and quality.

rapid freezing

most bacteria will remain dormant (but still alive)

Slow freezing

more harmful because ice crystals disrupt cell structure

Why is biotechnolgy used in the food industcry

To improve food quality - better taste, texture, and nutrition.

To make food last longer - using microbes or enzymes to slow spoilage.

give examples of producrs that are overdependent on the use of microrganisms

Yogurt - made by Lactobacillus and Streptococcus bacteria.

Cheese - made using bacteria and molds.

Bread - yeast (Saccharomyces cerevisiae) helps dough rise.

what are some of the controveries surrounding biotech

The main controversies are about safety, ethics, environment, and who controls biotechnology.

give examples of animal toxins

Here's a simple list of animal toxins 👇

Pufferfish toxin (tetrodotoxin) - blocks nerve signals; very deadly.

what foods are associated with acyloamide

French fries 🍟

Potato chips

Toast and bread crusts 🍞

In short:

Acrylamide is found in fried or baked starchy foods like potatoes, bread, and coffee when they're cooked until brown or crispy.

how would you explain the sentance "the dose makes the posion"

Anything can be harmful if you take too much of it — even things that are normally safe.

what is high pressure processing

is when food is put under very strong pressure to kill germs without heat.

what is pulsed eletcric fields

uses short bursts of electricity to kill germs in food.
It helps keep the food fresh and safe without using heat.