Simultaneous Fractionation of Low-gluten Flour and Gum from Durian Seed: Process-Properties Relationship

Abstract

Abstract In this study, valuable low-gluten flour and gum were fractionated simultaneously from durian seed via a green and safe aqueous extraction method at maximum atom economy. As the extraction process significantly affected the properties and hence, the application of the flour and gum, the process-properties relationship of extraction temperature and W/S ratio were investigated and presented in this paper. The demucilaged durian seed flour (DDSF) and durian seed gum (DSG) solubilities and water absorption capacity (WAC) were found improved at higher extraction temperature (85 °C) due to bond cleavage and retention of amylose and hydrophilic amino acids. Furthermore, DSG with a solubility of 46.67% was the highest that can be achieved by current aqueous extraction method as further increase of W/S ratio and DSG yield exerted no effect on the solubility. Besides, the oil absorption capacity (OAC) of DSG was found higher than the DDSF due to the presence of nonpolar amino acids and fatty acids that tended to bind with the hydrophobic oil. OAC was mainly determined by the extraction yield and distribution of these hydrophobic fraction, instead of the degree of degradation. Higher overall yield was found at higher extraction temperature of 85 °C for simultaneous extraction of DDSF and DSG. While lower W/S ratio at 1:1 was preferable to obtain higher yield of DDSF, a higher W/S ratio at 5:1 was required for higher yield of DSG. Other than the extraction temperature, drying temperature and duration were key factors determining the colour of the extracted DDSF and DSG.