بررسي و توليد امولسيون نوشيدني فرسودمند حاوي اسيد لينولئيك مزدوج ﴿CLA﴾

چكيده انگليسي :

Evaluation of Production of Functional Beverage Emulsion Containing Conjugated Linoleic Acid CLA Maryam Nikbakht Nasrabadi m nikakht@ag iut ac ir October 20 2013 Department of Food Science and Technology Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisors Sayed Amir Hossein Goli Assist Prof amirgoli@cc iut ac ir Ali Nasirpour Assist Prof a nasirpour@cc iut ac irAbstractNowadays consumers are looking for food products which are useful for human health in addition tosatiate their hunger The term functional food refers to food containing one or several nutrients withspecific beneficial functions in the human body It is recently proven that some fats and oils in addition tohaving nutritional value have positive effects on the human body One of the functional lipid compoundsis conjugated linoleic acid CLA The aim of this study is to prepare a functional beverage containingCLA as a functional compound Because CLA has a low water solubility and beverages are mainlycomposed of water in order to add CLA to beverage oil in water emulsion can be used which is calledbeverage emulsion Beverage emulsions are thermodynamically unstable systems and tend to break downdue to various physicochemical mechanisms during storage Emulsions composed of arabic gum AG 5 10 w w CLA oil 3 5 6 5 w w and xanthan gum XG 0 1 0 3 w w were prepared and theirmean droplet size D43 opacity speci c gravity viscosity and heat stability was investigated applyingresponse surface methodology RSM The effects of main emulsion components were evaluated andresults revealed that their contents had a direct impact on physicochemical characteristics of emulsions Itwas generally concluded that the increase in AG and XG content led to increase in density turbidity viscosity and stability D43 decreased when AG concentration increased and increased by the XG content The oil content has resulted in increasing D43 and turbidity whereas was negatively effective on heatstability and specific gravity Applying RSM emulsion with the highest specific gravity turbidity viscosity stability and smallest average droplet size considered as an optimum product Optmizationbased on D optimal design was succesfully accomplished for selecting a CLA oil in water beverageemulsion containing 3 5 w w oil 10 AG w w and 0 3 w w XG as an optimum formula Theemulsion and finished product stability and oxidative stability were investigated during 49 days of storageand results showed that specific gravity and viscosity decreased insignificantly during this time Opacity heat stability specific surface area and creaming index decreased significantly and surface tention pH size index D43and span increased in the passage of time Peroxide value increased until the day 21 andbegan to fall down after that time TBA and Totox values increased significantly during storage time Turbidity of finished product decreased significantly and turbidity loss rate was calculated 0 038 A daywhich was low and indicated the good stability of diluted form Totally the oxidative stability of theCLA beverage emulsion and its stability in beverage were acceptable upto 28 days and 21 days respectively Keywords Arabic gum Xanthan Conjugated linoleic acid Emulsion beverage Functional Optimization Oxidative stability

نيكبخت نصرآبادي، مريم

بررسي و توليد امولسيون نوشيدني فرسودمند حاوي اسيد لينولئيك مزدوج ﴿CLA﴾

صمغ عربي , زانتان , بهينه سازي , پايداري اكسيداتيو