Modelling the β-amylase activity during red sorghum malting when Bacillus subtilis is used to control mould growth

Effect of cold shock on the enhancement ofβ-amylase activity during malting and malt processability for a red sorghum intended for brewing use

“…Our results make the assumption that the reduction of enzyme synthesis in the aleurone layer (owing to an ABA concentration increase), combined with that of the hydrolysis of grain reserves (owing to low temperature and a decrease in enzyme synthesis), negatively affects the diffusion rate of enzymes as well as signalling molecules in the endosperm and increases the lag phase of enzyme synthesis in the scutellum. This hypothesis is supported by the fact that β-amylase synthesis in red sorghum occurs mainly in the scutellum, as proposed by Bwanganga et al (5). On the other hand, it is known that sugar levels can repress or induce enzyme synthesis in the scutellum.…”

“…Indeed, it has been reported that the exposure of plants to the cold induces metabolic changes that are not only due to the reduction of enzymatic reaction rates, but also and specifically to the reconfiguration of the metabolome (9). Our previous results have shown that the rate of β-amylase synthesis was inversely proportional to the germination temperature increase, while that of α-amylase increased proportionally with the increase in the germination temperature (5,6). Several events take place during germination-the production of phytohormones, the activation of enzyme synthesis, the hydrolysis of the reserves of grain and various interactions.…”

Enzymatic activity in braúna seeds subjected to thermal stress

“…It was reported, during the germination of Sorghum bicolor seeds, (TAWABA et al, 2013) that from 24°C, a 4-8°C rise in the temperature was sufficient to reduce the synthesis of β-amylase. Diminishing enzyme synthesis is consistent with lower maltose and maltotriose release at high temperatures.…”

Suitability of the Weibull four-parameters model to predict the induction phase ofα-amylase production during red sorghum malting when a steep in dilute NaOH is used prior to a re-steep in aBacillus subtilis-S499 based treatment

“…The red sorghum cultivar used was obtained from the Democratic Republic of Congo and has been described previously . Sorghum malts were obtained as described by Bwanganga et al .…”

“…The AA # = {[( AA ω − AA 0 )/( AA − AA 0 )]} is dimensionless and tends to one at the maximum activity. The value of β is the expression of the speed at which the maximum activity is achieved [ β = ∂ln(ln AA # )/∂ln GD ], and − (ln α )/ β is the starting point, that is, the advantage offered by the steeping treatment or the expression of the capacity of the treatment to improve α ‐amylase activity . Minitab 16 software was used for statistical analyses: analysis of variance, goodness of fit, stepwise regression, general linear model, fitted line plot and scatter plot.…”