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BACTERIAL AND MOLD STARTER CULTURES
NOTE A MORE EXTENSIVE DISCUSSION OF THIS TOPIC CAN BE FOUND ON THE INTRODUCTION PAGE.
One can not always depend on indigenous bacterial contaminants to produce a desireable result. Specialized meat cultures can be added to impart added safety, color and taste to dry-cured or fermented sausages. Fermentation is best controlled by the addition of selected strains of Lactic Acid bacteria (a large family of bacteria), whereas members of the Staphylococci contribute to the color, aroma, flavor and stability of the sausage. Also available are cultures that produce bacteriocins that provide anti-lysterial effects and bioprotection from pathogens.
Lactic Acid Starter:
Starter cultures accelerate the formation of lactic acid and drop the pH (to about pH5.3) of salami, which can inhibit the growth of spoilage bacteria and pathogens. The rapid decline of pH not only gives the salami a unique lactic acid flavor, but also increases the firmness of texture and mouth feeling due to the acidic denaturation of meat proteins. The lactic acid bacteria (LAB) in starter cultures have been shown to inhibit Staphylococcus, gram-negative bacteria, and E. coli, by 97.8% after 48 hours of fermentation. Further studies of LAB starters (which often contain one or more species) of Pediococcus cerevisiae, Lactobacillus platarum and Staphylococcus carnosus, have shown a very wide spectrum of inhibition activity on Staphylococcus epidermidis, Lysteria monocytogenes Klebsiella oxytoca, Shigella dysenteriae and germination of the spores of Bacillus subtilis and Bacillus cereus, and Pseudomonas fluorescens. I've added extensive coverage to the starter cultures produced by Chr. Hansen, Inc., producers of freeze dried starter cultures on my main web pages [Introduction section - Starter Cultures]
BIOPROTECTIVE CULTURES:
Listeria is a constant concern in the meat industry.The US-FDA reports (June /29/2009) Listeria monocytogenes (Lm) has been responsible for several outbreaks of food borne illness domestically. Each year approximately 2500 people become seriously ill due to Lm infections. Nearly 500 of these die from their infection. Listeriosis only accounts for about 0.02% of illnesses due to food borne disease, but it causes 27.6% of all deaths due to foodborne infection.
Cultures containg Staphlococcus xylosis, Lactobacillus curvatus, and Pediococcus acidilactici provide protection against a population explosion of Lm in fermented sausages. Chr. Hansen North America produces several bioprotective meat cultures; Bactoferm F-LC and the newer Bacterferm BL-C-48. A source for these is listed below
EXTERIOR MOLD CULTURES:
Many fermented sausages, especially Northern Italian and American-Italian dry salami are generally covered in a pure white mold; much like a good French brie cheese. This is desirable and contributes to the overall taste of the final product. The mold (fungus) is a variety of Penicillium (Penicilium nalgiovense) and is applied to the surface casing after stuffing and tying the salami, prior to fermentation. The easily available product is Bactoferm M-EK-4.
CHOOSING A STARTER CULTURE
Consider the qualities you want in your final product. Are you trying to mimic a particular geographic style; German Polish, Italian, etc.? Would you like it to be having a tang [a sharp or acidic] tang or a mild one? What about sweetness? What about salt—with its concentration kill or inhibit the starter culture? And then there is the flavor component—how do you define that quality? Do you consider it divorced from the added spices or in addition to their characteristics? Often it’s a matter of a somewhat educated choice based on experimentation.
American style [whatever that means] is generally recognized by a short fermentation that produces a very low pH [high acid content]. These products are mostly produced commercially where a high acid content complies with USDA guidelines and super-fast fermentation gets the product “out the door” and to the consumer quickly.
Dry cured sausages from Southern Europe and the Balkans tend to be on the “sweet” side—lower acid [higher pH] and often allowed to dry several months. Rarely will you find Italian, French, Spanish, Serbian salami or Bulgarian Loukaniko to have a tart, acidic tang.
On the other hand, fermented sausages from Northern and Eastern Europe generally have a sharp tang [lower pH] whether they are dry-cured or semi-dry-cured [“summer-type” sausage]; Think German Thüringen, Swedish medvurst,
Cultures distributed by Internet online companies are of the freeze dried type. In order to choose the correct culture the following advise may be used as general guidelines. Paragraph numbers refer to the discussion of starter cultures on the INTRODUCTION page.
· Traditional South and North European, choose cultures in paragraph 5.1.1.
· North European fast fermented, choose cultures in paragraph 5.1.2.
· US style, choose the extra fast and very fast cultures in paragraph 5.1.2
· To enhance nitrate reductase activity choose from paragraph 5.1.3
· To produce a consistent surface molds, choose from paragraph 5.1.4
· To provide Lysteria protection, choose from paragraph 5.1.5
Technical information sheets provide the recommended temperatures for fermentation, however, bacteria will also ferment at lower temperatures, just more slowly. For example, the technical information sheet for T-SPX lists temperatures as 26-38º C, optimum being 32º C. T-SPX will ferment as well at 20-24º C which is not uncommon for "European" style sausages, and 48 hours or more is not atypical.
When freeze-dried cultures are used it is recommended to disperse them in distilled or purified water. Adding 25 grams of powdered culture to 200 kg (440 lbs) of meat makes uniform distribution quite challenging. That comes to about 1/2 teaspoon to 4.5 kg (10 lbs) of meat and the culture must be very uniformly dispersed otherwise defects will occur later on. For those reasons it is advisable, especially at home conditions, to mix 1/2 tsp of culture in 1/2 cup (150 ml) of distilled water and then pour it down all over the meat. Any tap water which is chlorine free will do, the problem is that different cities, or countries, sanitize water in different ways. Chlorine will kill bacteria and the process will suffer. For this reason it is recommended to use distilled water.
Mixing freeze-dried cultures with cold water for 15-30 minutes before use allows them to "wake up" and to react with meat and sugar faster when introduced during the mixing process.
Once fast-fermented starter culture or GDL has been added to the sausage mix, the mix should be filled into casings.
I suggest that don't put your trust in indigenous bacteria that contaminate ground meats instead purchase a culture from a supplier, such as Butcher and Packer Company. Use those suggestions in lieu of those given with any formulation or recipe. When you choose a starter, check with the vendor or the manufacture's guidelines as to the required time and temperature for optimum fermentation. Dissolve freeze-dried culture in a couple of tablespoons of de-chlorinated water; add a small pinch of glucose (dextrose) and set aside for 2 or 3 minutes before use.
