SEM 2 Lecture 10

MICROBIOLOGICAL ANALYSIS OF FOOD SAMPLE

FOOD MICROBIOLOGY

is the study of the microbes that inhabit, create, or contaminate food including the study of microbes which causes food spoilage.

synthesis a new compound that cause spoiling of the food.

produced enzymatic changes and contributing off-flavours by mean of breakdown of product.

How microorganisms can cause deterioration of the food?

Food Bioprocessing

Food produce by using biological process

starter culture

A concentrated preparation of live cells that is added to raw material to initate fermentation rapidly.

Food Bioprocessing

food-grade microorganisms are used to produce different types of fermented food using raw materials from animal and plant sources

Food Biopreservation

s a food biological preservative by using antimicrobial metabolites

Food Biopreservation

beneficial bacteria are used to prevent food spoilage and get rid of harmful pathogens.

Lactic acid bacteria (LAB)

most commonly used Biopreservative due to their unique properties and because they are harmless to humans.

Probiotics

Is a concentrated supplement of beneficial live cells of bacteria (friendly bacteria) culture taken orally intended to improve our health by promoting our body’s natural immunity and improving digestion system.

Foodborne Disease

Is a disease cause by consumption of contaminate during various stage of handling between production and consumption by many pathogenic microorganisms

Food Spoilage

is a condition of contaminate food due to Growth of microorganisms in food and The action of microbial heat stable enzymes

ASPERGILLUS specifically A. niger

It is the leading species important for food microbiologists.

Selected strains are used for commercial production of citric and gluconic acids

YEASTS

Most widely used microbes in the food industry due to their ability to ferment sugars to ethanol and carbon-dioxide.

P. camemberti

Greyish conidia, useful in the ripening process of camembert cheese.

Penicillium roqueforti

Used in ripening of blue cheeses.

Rhizopus nigricans

Sometimes called “bread mold”, is very common and is involved in the spoilage of many foods.

MUCOR (Mucor racemosus & Mucor rouxii)

involved in the spoilage of some foods and in the manufacture of others

food safety

proposed to provide a target for operational food safety management, leaving flexibility in the way equivalent food safety levels are achieved by different food chains.

food preservation

defined as the process of treating and handling food in such a way as to stop, control, or greatly slow down spoilage and, of course, to minimize the possibility of foodborne illness while maintaining the optimum nutritional value, texture, and flavor.

fermentation

a metabolic process in which an organism converts a carbohydrate, such as starch or a sugar, into an alcohol or an acid.

Indicator organisms

These are organisms used to suggest the sanitary quality of food or the possible presence of contamination.

Direct examination

This may include immediate microscopic or physical examination of food samples. useful for quick preliminary assessment.

Cultural techniques

These involve inoculating samples onto media to isolate and identify organisms. This remains a standard approach in microbiology.

Enumeration Methods

These determine the number of microorganisms present.

MPN or Most Probable Number

a statistical estimation method often used for organisms in liquid or diluted samples

Rapid methods

These are especially useful when rapid turnaround time is needed or when detecting specific pathogens or toxins.

includes immunological methods and DNA/RNA-based methods.