Enhancing the aroma of white whole sorghum flour using supercritical carbon dioxide
Arda Tuhanioglu, Scott Lafontaine, Ali Ubeyitogullari
Abstract
Removal of undesired odor-active compounds from sorghum flour is vital for the widespread production of sorghum-based foods. This study investigated the use of supercritical carbon dioxide (SC-CO2) for the extraction of volatile compounds (VCs) from white sorghum flour. The extraction temperature (33.18-66.81°C), pressure (8.18-41.82 MPa), and time (1.32-4.68 h) were optimized for the removal of 11 VCs (decane, undecane, tetradecane, dodecane, hexanal, nonanal, hexanol, dodecanol, limonene, styrene, and butylated hydroxytoluene) from whole white sorghum flour using a central composite response surface design. The maximum VC removal (∼89%) was obtained at 60°C and 15 MPa with 2 h extraction time. SC-CO2 extraction at higher pressures (> 15 MPa) or lower temperatures (<60°C) did not improve the VC removal. After SC-CO2 treatment, water absorption index, oil absorption capacity, and swelling power increased, whereas moisture/lipid contents, water solubility index, and particle size reduced significantly (p<0.05). The lightness of the sorghum flour treated with SC-CO2 increased significantly compared to untreated sorghum flour, while the yellowness decreased after SC-CO2 extraction (p<0.05). Overall, this study developed a novel green approach to enhancing the aroma of sorghum flour, which has a high potential for scale-up, and generating sorghum flours with more neutral flavors for numerous food applications.