Colloidal properties of titanium dioxide stabilized pickered emulsions


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Türk T., Güven O., Çelik M. S.

XVIIth Balkan Mineral Processing Congress, Antalya, Türkiye, 1 - 03 Kasım 2017, ss.305-310

  • Yayın Türü: Bildiri / Tam Metin Bildiri
  • Basıldığı Şehir: Antalya
  • Basıldığı Ülke: Türkiye
  • Sayfa Sayıları: ss.305-310
  • İstanbul Teknik Üniversitesi Adresli: Evet

Özet

Beverage emulsion is a unique class of oil in water emulsion that is prepared as an emulsion concentrate and usually stabilized with the addition of polysaccharides like Arabic gum along with various hydro colloids. On the other hand, its physicochemical properties are generally modified with water soluble agents like glycerol which also provides better stability and rheological properties. In recent years, however, pickering emulsion concept which involves inorganic additives like titanium dioxide is added to control the stability of emulsion. In pickering emulsions particulate additives like titanium dioxide or biopolymer aggregates are added with the aim of scattering light to obtain cloudier or opaque emulsion products. The aim of this study was therefore to produce a model beverage emulsion with sufficient stability mainly with the addition of titanium dioxide as a stability agent. Towards this aim, surface and colloid chemistry tools, namely zeta potential and turbidity were conducted to characterize the stability of produced pickered emulsions. The final appearance of the selected beverage emulsion was adjusted with the sequential addition of xanthan gum, glycerol and titanium dioxide and also in mixture form. by adapting zeta potential and turbidity measurements and try to determine the optimum amount with sufficient product quality and stability. The results suggested that the zeta potential of originally negatively charged emulsion was slightly affected by the addition of titanium dioxide and glycerol whereas a significant change was obtained upon the addition of xanthan gum. Similar trends were also observed in both absorbance and rheological measurements which in turn showed the importance of surface charge in emulsion systems for obtaining good dispersion in system. These kinds of systems very much mimic flotation systems where the interaction of particles, bubbles/oil drops, dispersing and depressing agents together with collectors determine the destiny of emulsion and in turn flotation recoveries.