Biomedical Engineering Reference
In-Depth Information
Fig. 11.2
Process chart for
togwa preparation
as they hydrolysed starch [
14
] . The dominance of
L. plantarum
was probably
because of its acid tolerance and its ability to effectively utilise different carbon
sources. Obligative heterofermentative
Lactobacillus brevis, L. fermentum
and
W. confusa
, and homofermentative
Pediococcus pentosaceus
were also among
dominant LAB strains in togwa [
14
] .
Issatchenkia orientalis
was the predominant
yeast whereas
S. cerevisiae, Candida pelliculosa
and
C. tropicalis
were also among
the most common yeast isolates (Table
11.2
).
Hellström et al. [
16
] isolated a number of yeast strains from togwa fermenta-
tions, identified them using API and molecular techniques, and determined their
phytase activity. Yeast strains with high phytase activity could serve as alternatives
for mineral fortification or the addition of phytases in order to improve the mineral
availability of fermented foods through elimination of the metal-chelating com-
pound phytate. The lactic acid bacteria may also promote phytate elimination as the
acidification increases the activity of endogenous cereal phytases [
17
] .
In addition to the elimination of antinutritive compounds, the microflora of togwa
may produce beneficial compounds such as B vitamins in food fermentations.
Hjortmo et al. [
18
] investigated folate production in togwa fermented with previously
isolated togwa-adapted yeasts [
16
] . Tetrahydrofolate and 5-methyl-tetrahydrofolate
were the dominant forms. The concentration of the latter folate type substantially
