15B-4 |
Creaming and sedimentation of emulsion in citrus drink |
A. R. TAHERIAN and P. Fustier. Food Research & Development Center, Agriculture & Agri-Food Canada, 3600 Cassavant Blvd. W., Sainte-Hyacinthe, QC J2S 8E3, Canada Emulsion stability in citrus drinks is one of the criteria of quality and ringing or creaming has been considered as a quality defect. Modified food starches, on the other hand, are the most widely accepted alternative to gum arabic for use as the beverage emulsion stabilizer. The properties raised from emulsions prepared with different types and concentrations of starch could provide useful information for formulation of a relatively stable emulsion. The objectives of this study were to investigate the suitable concentration and type of modified starches for a relatively stable emulsion in both concentrated and diluted forms. Oil-in water emulsions were prepared from 10,12 and 14% modified starches (Purity gum be and purity gum 2000 provided by National Starch and Chemical Company) and constant ratio of coconut oil (10% w/w). Using both Quick Scan and Wintrobe tube, creaming and sedimentation rates of dispersed solutions were evaluated prior to the homogenization. After homogenization, opacity, size index, refractive index, apparent viscosity and density of each prepared emulsions was tested and compared. The results indicated that Purity Gum Be can form more stable emulsion compare to Purity Gum 2000 . The least amount of creaming and sedimentation were associated with mulsion formulated from 14% Purity Gum Be. Rheological tests also indicated that increase in viscosity of external phase when decreasing the amount of water addition could play a positive role in increasing the stability of emulsion. In case of purity gum 2000, both creaming and sedimentation values were decreased along with increasing the level of starch. These values in comparison to the emulsions formulated with purity gum Be were almost two times greater.The quantitative evaluation of creaming and sedimentation rates by Quick Scan were also in agreement with the visual observation. Obtained results will be helpful for prevention of ringing as a quality defect.
Session 15B, Citrus
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