part 3c Flashcards
what are more natural antimicrobials?
natamycin, lactoferrin, carnobacterium maltaromaticum
what is macrolide?
antibiotic produced by bacterium that contains macrocyclic lactone ring
natamycin produced by bacterium _____ and industrially produced by ____
streptomyces natalensis; fermentation
natamycin hydrophobic or hydrophilic?
hydrophobic
phys properties of natamycin?
white/off-white solid, tasteless/odourless, very heat/pH stable, not very water sol
what is activity spectrum of natamycin?
yeasts and moulds
mech of action for natamycin?
incorporation into cyto mem–>pore formation and cell leakage and/or ergosterol binding (loss of essential membrane enzyme functions)
natamycin is an ___, and has limited ____ agent activity
antimicotic; antimicrobial
food uses for natamycin?
North America, cheese surface treatment ; EU bakery/dairy, processed meats, wine
-also topical drug for eye infection and for med devices
how come 40ppm (which is greater than natamycin’s water solubility) allowed in wine?
alcohol improve solubility in wine
what is lactoferrin?
glycoprotein found naturally in milk/dairy, produced by lactic acid bacteria
what bacteria is lactoferrin active against?
both gram neg and pos!
approved uses for lactoferrin:
surface spray for uncooked beef carcasses
perks of lactoferrin?
promote cell growth, antioxidant properties
what is CB1?
facultative anaerobe present naturally in enviro (soil)
CB1 produces ____ that are active against ____
bacteriocins; Listeria monocytogenes (gram positive)
CB1 approved for use as:
surface spray for vacuum packaged wieners and sliced meats (ready to eat)
what is protamine?
highly positively charged (arginine rich) protein, not very acidic, temp stable under 35 degrees
major source of protamine?
fish sperm
protamine activity spectrum?
gram pos and neg, yeasts, moulds
mech of action for protamine?
binds to cyto mem, result in rapid leakage
how does protamine work as drug?
used in combo with insulin to improve longevity, reduce flu-like symptoms of taking insulin
what does HAMLET stand for?
human alpha-lactalbumin made lethal to tumor cells
what is HAMLET?
human milk-protein lipid complex isolated from breast milk
how is HAMLET an adjuvant?
works in conjunction with antimicrobial agent by increasing sensitivity
how does HAMLET work to increase antimicrobial sensitivity?
alpha-lactalbumin + oleic acid complex has strong interaction with cyto cell wall to increase sensitivity to antimicrobial agents
how is HAMLET an answer to resistant strain concerns?
broad spectrum antimicrobial activity as adjuvant
examples of plant antimicrobials?
citral (citrus), carvacrol (oregano), thymol (thyme) with antimycotic, gram + and - activities
how get plant antimicrobials?
pressing/extraction (crude mix)
what are antimicrobials from animals?
chitosan, lysozyme
what is chitosan?
polysacc isolated from exoskeleton of arthropods with broad spectrum antimicrobial activity
chitosan is hydrolysate of ___ which is second most common in the world
chitin
what is lysozyme?
protein isolated from egg white, active against gram + pathogens
why is pH activity range not optimal for lysozyme?
most active 6-9, but most food is <5
lysozyme approved for use in ___ for Canada, also in ___ for EU
cheese; wine
is lysozyme temp stable?
yessss
mech of action for lysozyme and chitosan?
cyto wall destruction
___ not approved for food use in Canada, but ___ has GRAS
chitosan; lysozyme
examples of antimicrobials from microorg:
pediocin, others produced by lactobacilli species
what is pediocin?
bacteriocin isolated from pediococcus acidilactici
phys properties of pediocin?
water sol, active over wide pH range, active against gram positive
what are CAPs?
cationic antimicrobial peptides; produced from protein isolates via protease treatment
what is activity spectrum of CAPs?
bacteria, fungi, molds, viruses
how is CAPs effective against viruses?
hydrolyze phospholipid coat
what is antimicrobial design?
consider gram + and -, note cell wall is neg. charged (N-AMA), 12-50 aa size, amphiphilic, cationic, flexible (alpha helix), bind to create pores in cell mem *control hydrophobicity, charge
what is intelligent/smart packaging?
based on chem compound response (typically colour) to changes in pressure, temp, pH, O2/CO2, electrochem, moisture, etc.
how does thermochromic cap work for coffee?
as temp changes, expansion happens and crystals change structure and reflect light diff.
why not see smart packaging much?
not consumer driven, cost, reliability, stability, liability
why liability issues?
leakage into foods, false pos. or neg.
