title: Physicochemical and functional properties of rapeseed protein isolate: influence of antinutrient removal with acidified organic solvents from rapeseed meal.
abstract: The presence of antinutritional constituents in rapeseed protein products (RPI), such as polyphenols, phytates, allyl isothiocyanates, and glucosinolates, is a formidable constraint. The effect of antinutrient removal from rapeseed meal with an organic solvent mixture (methanol/acetone, 1:1 v/v, combined with an acid (hydrochloric, acetic, perchloric, trichloroacetic, phosphoric)) on the physicochemical and functional properties of RPI was investigated. The extraction resulted in a substantial reduction of antinutrients from RPI, especially polyphenols and phytates, with concomitant decreases in protein yield and solubility. Treatment harbored significant improvement in the degree of whiteness, which was highest in the perchloric acid case. Surface hydrophobicity and free sulfhydryl group of RPI changed considerably, with perchloric acid-treated samples showing higher values, whereas the disulfide content remarkably increased in trichloroacetic acid- and phosphoric acid-treated samples, signifying aggregation. Intrinsic emission fluorescence and FTIR spectra showed significant changes in proteins' tertiary and secondary conformations, and the changes were more pronounced in samples treated with higher concentrations of acids. No appreciable alteration appeared among the electrophoretic profiles of proteins from pristine meal and those treated with lower levels of acids. Interfacial surface properties of proteins were variably improved by the solvent extraction, whereas the converse was true for their extent of denaturation. The results suggest that the physicochemical and conformational properties of RPI are closely related to its functional properties.
authors.affiliation: Department of Food Engineering and Technology, School of Engineering, Tezpur University , Tezpur, Assam, India.
authors.forename: Manashi
authors.initials: M
authors.lastname: Das Purkayastha
authors.forename: Jyotchna
authors.initials: J
authors.lastname: Gogoi
authors.forename: Dipankar
authors.initials: D
authors.lastname: Kalita
authors.forename: Pronobesh
authors.initials: P
authors.lastname: Chattopadhyay
authors.forename: Khonamai Sewa
authors.initials: KS
authors.lastname: Nakhuru
authors.forename: Danswrang
authors.initials: D
authors.lastname: Goyary
authors.forename: Charu Lata
authors.initials: CL
authors.lastname: Mahanta
mesh_terms: D029741:Brassica rapa / Q000737:chemistry*; D055598:Chemical Phenomena; D005511:Food Handling / Q000379:methods*; D057927:Hydrophobic and Hydrophilic Interactions; D009753:Nutritive Value; D010472:Perchlorates; D010833:Phytic Acid / Q000032:analysis; D010940:Plant Proteins / Q000737:chemistry* / Q000302:isolation & purification; D059808:Polyphenols / Q000032:analysis; D011487:Protein Conformation / Q000187:drug effects; D012995:Solubility; D012997:Solvents; D013438:Sulfhydryl Compounds / Q000032:analysis
chemical_list: D010472:Perchlorates; D010940:Plant Proteins; D059808:Polyphenols; D012997:Solvents; D013438:Sulfhydryl Compounds; D010833:Phytic Acid; C576518:Perchloric Acid