THESE UNIQUE El Hassane Kéhien-Piho TOU - Nutridev

E.H. Tou et al. / International Journal of Food Microbiology 106 (2006) 52–60 57
mmol/l
mmol/100g of DM
1.2
1.0
0.8
0.6
0.4
0.2
0.0
25
20
15
10
5
0
SUPERNATANT
GRAINS
0 4 8 12 16 20 24 28 32 36
Soaking time (h)
glucose fructose sucrose
maltose raffinose melibiose
stachyose
Fig. 3. Changes in sugars in grains and in the supernatant during soaking. Bars
indicate standard deviation.
Concentration (mmol/l)
Temperature (°C)
60
50
40
30
20
10
50
40
30
20
10
SETTLING
0 0
SOAKING
0
0 4 8 12 16 20 24 28 32 36
Time (h)
Temperature Ethanol Acetate
Lactate pH
7
6
5
4
3
2
1
6
5
4
3
2
1
0
pH pH
In addition to these results, microbial counts were determined
in samples from different TPUs. In the unfermented wet
flour, counts were similar for the lactic acid bacteria and yeasts
(Table 4). Consistent with the fermentation patterns, at the end
of the fermentation LAB increased and became the dominant
microflora whereas yeasts decreased, though yeasts were still
present. Moreover, amylolytic lactic acid bacteria (ALAB)
were counted and found to increase during fermentation (from
5.1 to 6.1 log CFU/ml). However, the ALAB/LAB ratio (12%)
was constant (Table 4).
4. Discussion
As the flow diagram of ben-saalga production (Fig. 1)
shows, the processing of pearl millet is similar to that of other
African traditional processing of cereals into fermented dough
and pastes such as mawè, ogi in Benin, Ghana, Nigeria
(Blandino et al., 2003; Hounhouigan et al., 1993; Odunfa and
Table 3
Main biochemical characteristics of products during the processing of pearl
millet into ben-saalga in 24 TPUs (results are mean values in g/100 g DM with
standard deviation)
Dry
matter
Protein
Phytate
(IP6)
Sucrose
Raffinose
Washed grains 76.7T8.3 10.2T0.6 0.67T0.05 1.09T0.33 0.48T0.23
Soaked grains 59.3T2 10.1T0.6 0.63T0.10 0.27T0.17 0.21T0.16
Unfermented paste 7T3.2 8.7T1.2 0.51T0.13 0.03T0.02 0.04T0.05
Fermented paste 39.2T9.9 6.0T2.1 0.18T0.12 0.01T0.01 0.08T0.27
Ben-saalga 7.4T1.4 – 0.16T0.07 – –
Fig. 4. Changes in pH, temperature, ethanol, acetic and lactic acid concentrations
in supernatant during soaking and settling in pilot scale experiments. Bars
indicate standard deviation.
Adeyele, 1985; Tomkins et al., 1988). Without claiming to
thoroughly describe the nutritional characteristics of bensaalga
(further investigations are currently underway), some
preliminary conclusions can be drawn from the results. In
agreement with previous results (Svanberg and Lorri, 1997), in
all the TPUs investigated, during the lactic acid fermentation
step (settling) there was natural degradation of phytate, an antinutritional
factor (ANF) that reduces the bioavailability of
mineral micronutrients. As for a-galactosides such as raffinose,
Lactic acid; ethanol (mmol/l)
60
50
40
30
20
10
0
Lactic acid
Ethanol
PSE (14h) TPU (14h) PSE (24h) TPU (24h)
Fig. 5. Comparison between five traditional production units (TPU) and pilot
scale experiments (PSE) for lactic acid and ethanol concentrations in
supernatant during soaking. Bars indicate standard deviation.