Physicochemical characterization and stability of inulin gels

The ability of three commercial inulins (Raftilose (R) P95, Frutafit IQ (R), and Frutafit TEX (R)) with different chemical composition (oligo-polysaccharides profile) to form gels (at 25 and 50 degrees C) was evaluated. Raftilose (R) P95 (rich in mono-disaccharides) did not form gels, Frutafit IQ (R) (mainly oligosaccharides) gelatinized in the 30-60% w/w concentration range and Frutafit TEX (R) (mainly long-chain saccharides) in the 20-40% w/w range. Textural and thermal properties of the gels were studied and their stability was evaluated during storage at 4 degrees C. Frutafit TEX (R) gels (both fresh and during storage) were harder, more adhesive, and less cohesive than Frutafit IQ (R) gels (40% w/w). At 40% w/w, Frutafit TEV gels had a significantly higher amount of freezable water than Frutafit IQ (R), and the DSC thermogram line shapes indicated that ice melting was more uniform and occurred at higher temperatures in Frutafit TEX (R) than in the Frutafit IQ (R) gels. Ice melting profile was not significantly affected by both gelification temperature and storage time. Frutafit IQ (R) gels were more stable than Frutafit TEX (R) gels during storage.