Viscoelasticidad de sistemas fase grasa-almidón gelatinizado-hidrocoloide: Efecto de la congelación

NAVARRO A.S.; MARTINO M.N.; ZARITZKY N.E.

Sao Paulo

Congreso; I Congreso Iberoamericano de Ingeniería de Alimentos; 1995

Universidade Estadual de Campinas

Freezing rate effect was analyzed, together with the addition of triglyecerides to model suspensions of commercial corn starch (7 and 10% w/w) with and without xanthan gum (0.3% w/w). Transient curves of shear stress of samples thawed under controlled conditions were recorded with a viscometer (Haake Rotovisco RV2) of concentric cylinders. Bird-Leider model was used to obtain the viscoelasticity and structural breakdown parameters for the different systems, obtaining a satisfactory goodness of fit. The lipid phase modified the viscoelastic properties of the model systems. In all cases, samples frozen ultra-rapidly maintained the textural characteristics of the unfrozen samples. The addition of only 0.3% of xanthan gum protected the suspensions from the negative effect attributed to low freezing rates.