Optimization of Protein Extraction from DDGS Using Response Surface Methodology and the Properties of the Protein

DDGS is the major co product generated from the fermentation of grain, but it is high in protein and an inexpensive source of protein. To optimize the extracting process of protein from DDGS, Response surface methodology (RSM) has been developed using the three influential process variables: alkali concentration, extraction time and solid-liquid ratio. The properties of the protein were further investigated by SDS-PAGE and FTIR spectroscopy. From the RSM-generated model, the optimum conditions of protein extraction were identified as alkali concentration 0.626 mol/L, extraction time 2.3 h and solid-liquid ratio 1:37(g:mL). The predicted protein extracted from DDGS with the optimum extraction conditions was 0.3691 g/2 g DDGS, the validation experiments with this optimum solution were implemented in triplicate and the average dry weight was 0.3825. The relative error between expected value and experimental value was 3.50%.