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Time, Temperature, and Concentration Dependence of Ricinelaidic Acid–Canola Oil Organogelation
Author(s) -
Wright Amanda J.,
Marangoni Alejandro G.
Publication year - 2007
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/s11746-006-1012-6
Subject(s) - rheology , microstructure , canola , optical microscope , materials science , analytical chemistry (journal) , elasticity (physics) , chemistry , chromatography , scanning electron microscope , chemical engineering , crystallography , composite material , food science , engineering
Canola oil (CO) gels were formed using ricinelaidic acid (REA), a hydroxylated fatty acid, and the time, temperature, and concentration dependence of the resulting gel structure was studied using small‐deformation rheology, light microscopy, and powder X‐ray diffraction (XRD). Between 5 °C and 30 °C, REA concentration had a significant influence on gel elasticity ( P < 0.05), whereas temperature had a relatively lesser influence on gel rheology. Differences were observed in the scaling exponent of G ′ LVR with concentration above 20 °C, which were also correlated with significant differences in gelation time at 20 °C. However, the 5% gels at 5 °C, 20 °C, and 35 °C displayed similar microstructures and behaved like weak gels stabilized by junction zones. Most of the gels studied (i.e., the 2%, 3%, 4%, and 5% gels at 15 °C, 20 °C, and 25 °C) consisted of long, thin, fibrous REA strands, although at 25 °C, the 2% gel was characterized by more transient and circular entities. During 28 days’ storage, there were no apparent changes detected in gel microstructure by microscopy or XRD, despite increases in the gel's opacity.