Download - SPC, LPC, PI, Coliform - Home | University of Wisconsin ... · PDF fileThe Big Four SPC, LPC, PI, Coliform Scott Rankin, Ph.D. University of Wisconsin-Madison Food Science Keith Engel

Transcript
Page 1: SPC, LPC, PI, Coliform - Home | University of Wisconsin ... · PDF fileThe Big Four SPC, LPC, PI, Coliform Scott Rankin, Ph.D. University of Wisconsin-Madison Food Science Keith Engel

The Big Four SPC, LPC, PI, Coliform

Scott Rankin, Ph.D. University of Wisconsin-Madison

Food Science

Keith Engel WestfaliaSurge, Inc.

Farm Technologies Division

Page 2: SPC, LPC, PI, Coliform - Home | University of Wisconsin ... · PDF fileThe Big Four SPC, LPC, PI, Coliform Scott Rankin, Ph.D. University of Wisconsin-Madison Food Science Keith Engel

Significance

  Regulatory standard   Impact on pasteurized product   Premium programs   Troubleshooting

Page 3: SPC, LPC, PI, Coliform - Home | University of Wisconsin ... · PDF fileThe Big Four SPC, LPC, PI, Coliform Scott Rankin, Ph.D. University of Wisconsin-Madison Food Science Keith Engel

In general…

  Many procedural variations, highly defined practices   Method basis: anything present will grow, if it can   Individual cells (clusters, chains) each form a Colony

Forming Unit (CFU)   CFUs are counted

  25-250, 30-300, or?   Dilution math is done, e.g. 1:10 dilution, 50 colonies = 500 CFU/mL   Might be expressed as log#, e.g. 1000 = 3

  Precision – two SDs   Can be statistically complex

Page 4: SPC, LPC, PI, Coliform - Home | University of Wisconsin ... · PDF fileThe Big Four SPC, LPC, PI, Coliform Scott Rankin, Ph.D. University of Wisconsin-Madison Food Science Keith Engel

A plate to be counted

http://water.me.vccs.edu/courses/env108/lessons.htm

Page 5: SPC, LPC, PI, Coliform - Home | University of Wisconsin ... · PDF fileThe Big Four SPC, LPC, PI, Coliform Scott Rankin, Ph.D. University of Wisconsin-Madison Food Science Keith Engel

One, two, three…uh…?

Page 6: SPC, LPC, PI, Coliform - Home | University of Wisconsin ... · PDF fileThe Big Four SPC, LPC, PI, Coliform Scott Rankin, Ph.D. University of Wisconsin-Madison Food Science Keith Engel

Now what?

Page 7: SPC, LPC, PI, Coliform - Home | University of Wisconsin ... · PDF fileThe Big Four SPC, LPC, PI, Coliform Scott Rankin, Ph.D. University of Wisconsin-Madison Food Science Keith Engel

Remember heterotrophic

Page 8: SPC, LPC, PI, Coliform - Home | University of Wisconsin ... · PDF fileThe Big Four SPC, LPC, PI, Coliform Scott Rankin, Ph.D. University of Wisconsin-Madison Food Science Keith Engel

Petrifilm

Page 9: SPC, LPC, PI, Coliform - Home | University of Wisconsin ... · PDF fileThe Big Four SPC, LPC, PI, Coliform Scott Rankin, Ph.D. University of Wisconsin-Madison Food Science Keith Engel

SPC   Very common, referenced—NCIMS, PMO   Standard Plate Count   Also called:

  APC (Aerobic plate count)   HPC (Heterotrophic plate count)

  Plate loop count   Spiral plate count   BactoScan FC   Pour plate vs Petrifilm

Page 10: SPC, LPC, PI, Coliform - Home | University of Wisconsin ... · PDF fileThe Big Four SPC, LPC, PI, Coliform Scott Rankin, Ph.D. University of Wisconsin-Madison Food Science Keith Engel

SPC

  Growth conditions   SMA (Standard Methods Agar)

  Casein digest   Yeast extract   Sugar (glu)

  Aerobic   32°C ± 1; 48 hrs ± 3

Page 11: SPC, LPC, PI, Coliform - Home | University of Wisconsin ... · PDF fileThe Big Four SPC, LPC, PI, Coliform Scott Rankin, Ph.D. University of Wisconsin-Madison Food Science Keith Engel

LPC   Lab Pasteurized Count   Same as SPC with one exception:

  Milk is first heated to 145°F for 30 min   Kills most vegetative cells   Activates some spores (from where?)   Doesn’t kill “thermoduric” microbes   What survives pasteurization?

  In cheese   In UHT milk   Shelf life of fluid milk

Page 12: SPC, LPC, PI, Coliform - Home | University of Wisconsin ... · PDF fileThe Big Four SPC, LPC, PI, Coliform Scott Rankin, Ph.D. University of Wisconsin-Madison Food Science Keith Engel

Can be a big “Swissue”

Page 13: SPC, LPC, PI, Coliform - Home | University of Wisconsin ... · PDF fileThe Big Four SPC, LPC, PI, Coliform Scott Rankin, Ph.D. University of Wisconsin-Madison Food Science Keith Engel

PI

  Preliminary Incubation count   Same as SPC with one exception:

  Incubate milk at 55°F for 18 hrs, then plate   Growth of cold-lovers (from where?)   Compared to standard SPC#

Page 14: SPC, LPC, PI, Coliform - Home | University of Wisconsin ... · PDF fileThe Big Four SPC, LPC, PI, Coliform Scott Rankin, Ph.D. University of Wisconsin-Madison Food Science Keith Engel

Coliform Count   Think “colon”   Manure, environment

  Aerobic, facultative anaerobic; gram-, nonspore-forming rods

  Ferment lactose = acid and gas   32 or 35°F w/in 48 hrs

  Escherichia, Enterobacter, Klebsiella

Page 15: SPC, LPC, PI, Coliform - Home | University of Wisconsin ... · PDF fileThe Big Four SPC, LPC, PI, Coliform Scott Rankin, Ph.D. University of Wisconsin-Madison Food Science Keith Engel

Coliform Count

  What’s for dinner?   Yeast extract   Gelatin digest   Lactose (gas)

  Neutral red (red)

  Bile salts mixture   Crystal violet (caning treatment)   Salt

Page 16: SPC, LPC, PI, Coliform - Home | University of Wisconsin ... · PDF fileThe Big Four SPC, LPC, PI, Coliform Scott Rankin, Ph.D. University of Wisconsin-Madison Food Science Keith Engel

Coliform Count

http://water.me.vccs.edu/courses/env108/lessons.htm

Page 17: SPC, LPC, PI, Coliform - Home | University of Wisconsin ... · PDF fileThe Big Four SPC, LPC, PI, Coliform Scott Rankin, Ph.D. University of Wisconsin-Madison Food Science Keith Engel

Coliform Count

3m.com

Page 18: SPC, LPC, PI, Coliform - Home | University of Wisconsin ... · PDF fileThe Big Four SPC, LPC, PI, Coliform Scott Rankin, Ph.D. University of Wisconsin-Madison Food Science Keith Engel

The Big Four SPC, LPC, PI, Coliform

Scott Rankin, Ph.D. University of Wisconsin-Madison

Food Science

Keith Engel WestfaliaSurge, Inc.

Farm Technologies Division