Module 8 and 9 - Microbial Food Spoilage and Foodborne Pathogens

What aspect of food is not part of microbiology

• spoilage

• food safety

• fermentation

• food preservation

• insulin production

Answer explanation

What microbe is not commonly used as microbial biomass for food sources

• bacteria because they are pathogenic

• fungi because they may sporulate and propagate in the body

• algae because they are sourced from seawater and interrupt osmotic balance

• archaea because of difficulty in culturing

Answer explanation

spirulina is not known as

• Arthrospira

• cyanobacteria

• dihe

• tecuitlatl

• Fusarium venenatum

Answer explanation

Fusarium venenatum is used in quorn as a mycoprotein meat substitute with similar protein quality to egg and cows milk

What nutritional value is provided by Chlorella

• protein

• Vit B 12

• Beta carotene

• carbohydrates

• lipids

Answer explanation

Marmite and vegemite differ from probiotics because

• their processing involving heating and grinding

• they are composed of live microbes

• they prevent gout and uric acid buildup

• contain prokaryotic extracts

Answer explanation

probiotics are alive but due to heating and grinding the cells are lysed and the proteins / nucleic acids are denatured

how is fermentation controlled

• presence of oxygen and nutrients

• presence of oxygen and lactic acids

• presence of lactic acids and ethanol

• presence of nutrients and lactic acids

Answer explanation

homolactic: mainly glucose to lactic acid

heterolactic: mainly glucose to lactic acid, acetic acid, ethanol and carbon dioxide

mixed: multiple bacterial strains for mix of diff products (from homo and heterolactic)

Microbe responsible for wine making

• Saccharomyces cerevisiae

• Saccharomyces carlbergensis

• Candida

• Penicillium roqueforti

• Penicilium camamberti

Answer explanation

Sugars to ethanol (from fruits)

Saccharomyces cerevisiae is also responsible for ale beer, bread (as baker's yeast), cocoa fermentation (may also use Candida species)

Saccharomyces carlbergensis is for lager beer

penicillium is usually for cheese making

what is the difference with bottom and top fermentation

• microbes used

• temperature

• location

• duration

• all of the above

Answer explanation

What product of yeast fermentation causes bread to 'rise'

• CO2

• H2O

• lactic acid

• amino acids

Answer explanation

Which cheeses use molds that are anaerobes?

• camembert

• brie

• gorgonzola

• roquefor

Answer explanation