Stability of double emulsions for food applications


Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Gıda Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2015

Öğrenci: MERVE YILDIRIM

Eş Danışman: SERPİL ŞAHİN, SERVET GÜLÜM ŞÜMNÜ

Özet:

Double emulsion technology has potential effect on development of diversity and quality of functional foods by decreasing the oil and salt concentration, encapsulating and controlled release of valuable components. In this study, it was aimed to formulate stable double emulsions to be used for reduction of oil content of mayonnaise samples. W1/O ratios of primary emulsions, stabilized by polyglycerol polyricinoleate, were designed as 2:8, and 4:6, and (W1/O)/W2 ratios of double emulsions were 2:8, and 4:6. Double emulsion ratios, homogenization methods applied to primary emulsion (high speed homogenization, ultrasonic homogenization), and emulsifier types used in W2 phase (sodium caseinate, xanthan gum, lecithin-whey protein concentrate) were used as independent variables. Particle size and distributions, stability, encapsulation efficiency, rheological properties, long term stability and morphological properties of double emulsions were investigated. The most vi acceptable double emulsions were integrated into mayonnaise samples and quality parameters were investigated. Double emulsions prepared by sodium caseinate, and primary emulsions at W1/O ratios of 2:8 and 4:6 and (W1/O)/W2 ratio of 4:6 were found to have the higher stability values, higher apparent viscosity and lower particle size. High speed homogenization applied to primary emulsion affected particle size and viscosity positively, but did not affect stability and encapsulation efficiency of the double emulsions. Mayonnaise sample containing sodium caseinate at a ratio of 4:6 were not different from control mayonnaise in terms of stability and particle size. In addition, by the help of double emulsion, it was possible to reduce oil content of mayonnaise to 36.6%.