fermented foods Flashcards
microorganisms have been used for —- of years
1000s
what does fermentation do
extends shelf life,
improves nutritional value
increases lysine, vitamins B and C
enhanced taste aroma and texture
which processes are normally used in fermentation
bacteria
acids
yeast
alcohol
in the past which microorganism were used
naturally occurring
which microorganisms are now used
starter cultures
do any foods still contain the natural flora for fermentation
yes
what problems does using normal flora cause
inconsistency in quality and premature spoilage
also can produce dangerous toxins
the bongkrek (coconut press cake) is associated with what when homemade
deaths
is the coconut cake is not quickly covered with fungal growth you may get growth of ……..
Burkholderia gladiolo var cocovenenans
Burkholderia gladiolo var cocovenenans produces which toxins
Toxoflavin,
Bongkrekic acid (more deadly than cyanide )
what is tempeh made of
soy beans
name the traditional two stage production of tempeh
Soaking - bacterial fermentation
mould fermentation - add mould starter culture
what prevents the growth of pathogens in tempeh
natural lactic acid bacteria
what is the danger with tempeh
insufficient acidification
how to prevent the dangers with tempeh
investigate lactic acid bacteria for antagonistic effects (e.g Bacteriocins )
use bacteriocins produces as starter culture in soaking process
how can we improve a suitable organism
Mutagenesis and recombination
describe mutagenesis
physical treatment - irradiation
chemical treatment - ethyl methane sulphate
describe Recombination
conjugation
genetic modification
parasexual breeding (fungi)
protoplast fusion
why would you want to improve the organism
improve selected strain to give increased yield of product
faster growth etc
what is the new approach of genome shuffling
CSI then multi parental crossing via protoplast fusion
select most promising strain and then use second round of protoplast fusion
2 rounds of genome shuffling is equivalent to what
20 rounds of CSI
give an example of genome shuffling
antibiotic TYLOSIN
what is classical strain improvement
CSI
what is CSI
mutagenesis and screening
