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Food  Safety  and  Technology:  Microbial  Threats  and  Gene<c  

Engineering  BIOL  103,  Chapter  14  

Today’s  Topic  

•  Food  Safety  •  Food  Technology  •  Gene<cally  Modified  Foods    

Food  Safety  

•  Harmful  substances  in  foods  – Pathogens  (disease-­‐causing)  

– Foodborne  illness:  1.  Infec<on  from  pathogen  2.  Toxin  produced  by  microorganism  •   CDC:  “48  million  Americans  become  sick,  128,000  require  hospitaliza<on,  and  3,000  die  from  foodborne  illnesses).”  

Food  Safety  

•  Harmful  substances  in  food  pathogens  (Table  14.1:  Common  Foodborne  Pathogens  and  Illnesses):  

 Pathogens   Common  Source   Illness   Symptoms  

S.  aureus   Toxins  from  S.  aureaus  contaminated  foods  

Vomi<ng,  abdominal  cramps  

C.  botulinum   Improperly  canned  foods  and  contaminated  honey  

 Fatal  to  infants  

Salmonella   Undercooked  and  contaminated  poultry/eggs  

Diarrhea,  Vomi<ng,  Abdominal  cramps  

E.  coli   Raw  or  undercooked  meat,  vegetables,  contaminated  water  

Watery  or  bloody  diarrhea,  Death  

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Food  Safety  

•  Prions:  self-­‐reproducing  protein  par<cles  that  can  cause  a  disease  such  as…  – Mad  Cow  Disease  or  Bovine  spongiform  encephalopathy  (BSE)  

 

Mad  Cow  Disease  •  Diseased  prions  induce  healthy  (prion)  proteins  to  change  their  

shape  (from  alpha  helix  to  beta  sheets),  and  clusters  of  disease  build,  leaving  holes  in  the  brain.  

Mad  Cow  Disease  •  Feeding  prac<ces  doesn’t  help:  Recycling  dead  animals  into  

livestock  feed  increase  risks  spreading  of  abnormal  prions  •  Cooking  and  irradia<on  do  not  kill  or  deac<vate  abnormal  

prions.    

Food  Safety-­‐  Harmful  Substances  in  Food  

•  Chemical  contamina<on  – Pes<cides  

•  Important  role  in  food  produc<on  •  Concerns:    

1.  ________________________________  2.  ________________________________  

•  FDA  collects  samples  and  analyzes  food  samples  and  animal  feeds  for  illegal  pes<cide  residues.  

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Food  Safety  –  Organic  Alterna<ves  •  Organic  foods  

–  “Organic  Seals”  –  Concerns  regarding  natural  fer<lizer  

•  Manure  can  contribute  to  contamina<on  of  crops,  soil,  or  water  à  pollu<on  

–  Can  use  approved  synthe<c  and  natural  pes<cides  to  control  weeds  and  insects  

–  Microbial  contaminants  s<ll  found  

 

Food  Safety  

•  Animal  drugs  1.  An<bio<cs  to  maintain  animal  well-­‐being,  but  

overuse  can  develop  ____________________  microorganisms  à  illness  in  humans  

2.  However,  drug  residues  may  enter  human  food  à  _______________  or  illness  in  humans  

Food  Safety  

•  Pollutants  – Animal  manure,  factories  wastes/dioxins,  human  sewage  can  contaminate  food  produc<on  areas  

– Dioxins:  chemical  compounds  created  in  the  manufacture,  combus<on,  and  chlorine  bleaching  of  pulp  and  paper  and  in  other  industrial  processes.    

•  They  can  accumulate  in  the  food  chain  and  are  potent  animal  carcinogens.  

 

Food  Safety:  Harmful  Toxins  

•  Natural  Toxins  – Aflatoxins:  Carcinogenic  and  toxic  factors  produced  by  ___________.  

– Ciguatera:  A  toxin  found  in  tropical  __________.    •  Cooking  does  not  destroy  these  toxins.  

– Methyl  mercury:  Results  from  chemical  transforma<on  of  mercury  by  _____________.  

– Poisonous  mushrooms:  cause  stomach  upset,  hallucina<ons,  neurological  symptoms.  

– Solanine:  Toxic  substance  in  improperly  stored  raw  _________________________.  

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Figure  14.5  Toxins  in  the  food  chain  As  toxins  travel  up  the  food  chain,  they  become  concentrated  in  larger  fish.  

Figure  14.7  Government  agencies  that  help  protect  our  food  supply  Although  the  FDA  has  primary  responsibility  for  the  safety  of  much  of  our  food  supply,  many  government  agencies  provide  oversight.  

Keeping  Food  Safe:  Government  Agencies  (Pg587-­‐588)  

1.   FDA:  enforces  laws  governing  safety  of  ____________________  food,  except  meat  and  poultry.  

2.   CDC:  monitors/inves<gates  outbreaks  of  ________  _______________and  determines  proper  preven<on  

3.   USDA  FSIS:  enforces  laws  governing  safety  of  domes<c  and  imported  ________________  product.  

4.   USDA  CSREES:  develops  research  and  educa<on  programs  on  ______________for  farmers/consumers  

5.   EPA:  regulates  public  ___________,  approves  _________________and  other  chemicals  used  in  the  environment.  

Keeping  Food  Safe:  Consumer  

•  Keep  hot  foods  hot  and  cold  foods  cold  

1.  Clean  2.  Separate    3.  Cook    4.  Chill  (refrigerate  

promptly)  

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Food  Safety:  Separate,  don’t  cross-­‐contaminate!    

•  Separate  the  re-­‐usable  tote  bags  •  Use  different  cuhng  boards  for  vegetables  and  meat.  

Risk  for  Foodborne  Illness  

1.  Immune disorders 2.  Cancer 3.  Diabetes 4.  Long-term steroid use 5.  Liver disease 6.  Hemochromatosis 7.  Stomach problems  

Food  Technology  

•  Food  preserva<on  – Preserva<ves  

1.  Salt,  sugar    – Most  common  an<microbial  agents  

2.  An<oxidants  –   prevents  changes  in  color/flavor  caused  by  air  exposure  

Food  Technology  

•  Other  preserva<on  techniques  1.  Sal<ng  2.  Fermen<ng  3.  Drying    4.  Canning    5.  Hea<ng  (e.g.  pasteuriza<on)    6.  Irradia<on  –  controversial    

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Food  Technology  

•  Irradia<on  –  food  is  exposed  to  measured  doses  of  radia<on  to  reduce  or  eliminate  pathogens  and  kill  insects,  reduce  spoilage,  and  in  certain  fruits/vegetables,  inhibit  sprou<ng  and  delay  ripening.  

•  Why  are  food  manufacturers  reluctant  to  use  this  method  of  preserva<on?  

Food  Technology:  Irradia<on    

Food  Technology  

•  Bacteriophage:  viruses  that  infect  bacteria  

 

Food  Technology  

•  Bacteriophage  – Sprayed  on  ready-­‐to-­‐eat  meats  and  poultry  products  to  protect  people  from  bacterial  infec<ons  

•  Infect  only  bacteria  and  do  not  bother  mammalian  or  plant  cells  

– Must  declare  “bacteriophage  prepara<on”  

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Gene<cally  Modified  Foods  

Tradi<onal  Breeding  •  Cross  two  plants  and  

develop  hybrids  •  Takes  <me  

Gene<c  Engineering  •  Transform  specific  genes  •  Less  <me  needed  to  get  

desired  effects  

GM  foods:  Pros  and  Cons  

Benefits  1.  Enhanced  plant  growth  2.  _________    pes<cide  and  

fer<lizer  use  3.  Enhanced  ___________  

composi<on  4.  Enhanced  _____________  

Risks  •  Poten<al  for  new  ________  •  Herbicide-­‐resistant  weeds  •  Loss  of  ________________  

–  Biggest  con  of  unmonitored  GM  crops  

 

Food  Safety  •  There  is  no  scien<fic  evidence  that  gene<c  

engineering  and  irradia<on  of  foods  present  unacceptable  risks    

 

Gene<cally  Modified  Foods  

•  Regula<on  – _________  oversees  gene<cally  modified  foods  – Label  requirements  if  food  is  significantly  different    

•  Examples:    –  Changes  in  ____________  proper<es  –  Presence  of  ____________  that  consumers  would  not  expect  in  the  food  

–  Any  property  that  would  require  special  handling,  storage,  cooking,  or  preserva<ons.