1. Fermentations
meats

2. Types of fermentations
Definitions:
Natural fermentation
“Back-slopping”, “mother batch”
Starter-culture initiated

4. Common meat starters Lactobacillus sp. Pediococcus sp.
L. plantarum, L. pentosus, L. sake, L. curvatus
Pediococcus sp.
P. pentosaceus, P. acidilactici
Staphylococcus sp.
S. carnosus
Molds and yeasts
Penicillium camemberti, P. chrysogenum, P. nalgiovense

5. General process Grinding of meat (pH ~ 5.9) Drying Add:
salt (2.5-3%),
glucose ( %)
Nitrates/nitrites
Sodium erythorbate
Spices (sterilized)
Starter culture
Heating (optional)
Smoking (optional)
Fermentation (ripening)
Encasing (stuffing)

6. Choosing a starter General characteristics Lactobacillus sp.
Homofermentative
Growth down to pH 4.5
Tolerant of salt (up to 6%)
Tolerant of nitrates/nitrites
Lactobacillus sp.
“slow fermentations” (>96 hours; pH>5.5; oC)
More common in Europe
Pediococcus sp
“fast fermentations” (<48 hours; pH<5.2; ~40 oC)
More common in US

7. Other bits about “fast” process
Fast may also include “direct acidulation”
Glucono-delta-lactone (GDL)
Metabolized to glucose
Converted to lactic acid by homofermentative starters
Citric acid
Rely on acidification for preservation
Flavor almost exclusively from acid

9. Starters and color formation
Oxymyoglobin (red)  deoxymyoglobin (brown/purple)  nitric oxide myoglobin (pink)
Fermentation initially lowers oxygen concentrations (favors metmyoglobin)
Metmyoglobin = -OH bound to Fe (brown)

10. Cultures that maintain cured color
Staphylococcus carnosus, Kocuria varians (formerly Micrococcus varians)
Some lactobacilli (L. sakai, L. plantarum)
Slow fermentation
Nitrate reductase (NO3  NO2)
Nitrite reductase (NO2  NO)
Also chemically under acidic conditions
Also contribute to flavor (lipase, amino acid catabolism)
Metmyoglobin = -OH bound to Fe (brown)

11. Smoking/Heating/Drying (“curing”)
Phenols, carbonyls, organic acid inhibit microorganisms
Flavor and color (carbonyls + amino acids)
Drying
~10-20 oC or 2-3 weeks (generally)
Dry sausage (25-50% moisture loss; aw < 0.91)
Semi-dry (8-15% moisture loss; aw )
Heating
Depends upon style of sausage

12. Role of starter organisms
Mold and yeasts
On outside of casing
Can be cosmetic
Can be to decompose lactic acid
Protect product against spoilage molds

13. Spoilage Proteolytic organisms (Pseudomonas)
Hydrogen sulfide
Hydrogen peroxide producing organisms (Lactobacillus viridescens)
Heterofermenters (Lactobacillus brevis)
Souring (Brochrothrix sp.)

14. E. coli O157:H7 – Palmyra Bologna Company, March 2011

15. Good manufacturing practices (GMPs)
Standardize your Come-Up-Time (CUT)
Understand your equipment
Control relative humidity
Use standardized starter cultures
Weaver's-Kutztown plant in Lebanon

16. Good manufacturing practices con’t
“Degree-hour concept”
Degrees above 60 oF x hours to pH 5.3
Fermentation temperature Max degree-hour
< 90 oF oF oF
If fermentation temperature is 100 oF, must reach pH 5.3 within 25 hours.