[CH] Candida spp - was Fermented Mash Sauce Questions
George Nelson (70431.3065@compuserve.com)
Tue, 12 Jan 1999 23:25:39 -0500
Cameron Begg listed a whole bunch of Candida yeast species as possibilities
for what could be the organism(s) responsible for chile pepper mash. I
looked them up in _Food_and_Beverage_Mycology_ (AVI 1978, L. Beuchat) which
I borrowed from a colleague.
One point made in the book was: "[Candida] is the depository for a large
heterogeneous group of yeasts which lacks any important criterion for
classification except for the production of pseudomycelia." This is
unfortunate since once in awhile the classification gives clues to
metabolites or substrates (e.g. "Saccharomyces"). With no clue about this
from the classification, the type of acid produced in pepper mashes remains
unknown.
I was able to find references in the book to habitats of some of the
species on his list, though this is not the result of an exhaustive search
of the index.
Candida albicans - pathogenic
Candida catenulata - isolated from frankfurters
Candida guilliermondii - fresh shrimp, chlortetracyclene-treated poultry
Candida intermedia - eviscerated poultry
Candida kefyr - potential for use to produce protein from whey
Candida krusei - eviscerated poultry
Candida lipolytica - fresh fish, mutant tested for citric acid production
from palm oil
Candida parapsilosis - fresh shrimp, chlortetracyclene-treated poultry
Candida utilis - protein from whey, protein and vitamins from sulfite
waste liquor
Candida vini - Film former, metabolizes lactic acid, lives in lower salt
concentration, could be responsible for flavor development in fermented poi
Candida zeylanoides - frankfurters, fresh fish
There are few clues in the listing above to what is going on. Obviously, I
looked hard at the chapter on meats (it was in a nice table), but the
chapters on fruits and on vegetables gave few clues either.
Mark Ellis gave the good advice to plate samples of the mash (I would add
one should do so at different stages) and try to get identifications that
way. His point is well-taken about the futility of attempting
identification in view of the huge numbers of "bugs" in the world, but it
would be neat to see what they are.
Regarding the point about a lactic fermentation being more efficient. It
maybe would not be faster, but it would give more direct use of the
substrate to produce acid since it would occur in a single step. As for
the resulting flavor, lactic acid is mellower than acetic acid. Of course,
the other metabolites in addition the the acid determine the flavor
produced. If the organism is not "clean" and produces a lot of "stinky
stuff" it is worthless for this type of fermentation. My vote remains for
lactic acid as the one produced. Ion chromatography of the liquor could
settle the question.
Another value of extreme conditions (lots of salt) is that my impression of
chiles is they have little available substrate (sugar, whatever) to get a
fermentation going rapidly enough to exclude other organisms. Wine musts
are around 25% sugar and beer worts range from 10 to 20% or more
fermentables which gives the saccharomyces a good start towards their
desirable dominance.
Oh, before I forget, the book mentioned one Candida surprisingly missing
from Mr. Begg's list: Candida scottii =;-)
George Nelson
70431.3065@compuserve.com