Optimization of wheat sprouting for production of selenium enriched kernels using response surface methodology and desirability function

Response surface methodology and desirability function were used as tools to optimize wheat (Triticum aestivum L) germination conditions in the presence of SeO3Na2 to obtain selenium (Se)-enriched kernels. The effects of Se concentration (32.85–54.76 mg SeO3Na2/L), germination time (24–48 h) and germination temperature (18–25 °C) were investigated. The best Se-enriched wheats were selected based on selenomethionine (SeM) content, α-amylase activity (AC), and sprouting features such as kernel moisture (KM) content, germinated grains (GG) and radicle growth (RG). A second order polynomial model produced a satisfactory fitting of the experimental data considering the total kernel SeM content (R2adj = 58.8, S = 14.29), AC (R2adj = 59.80, S = 48.78), KM (R2adj = 71.30, S = 2.94), GG (R2adj = 66.70, S2 = 1.20) and RG (R2adj = 84.60, S = 23.38). Total desirability (δ) value was 67.6% in operational conditions (35 mg Se/L, 25 °C and 24 h germination). Under these conditions sprouted kernels contained 41.8 g/100 g, 95.5% and 98% for KM, GG and RG respectively, and 54 mg Se/kg as SeM and 54.8 CU of AC. In conclusion, the generated models with desirability methodology could be useful to optimize SeM content and alpha amylase activity in Se-enriched sprouted wheat kernels.