Tezin Türü: Yüksek Lisans
Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Gıda Mühendisliği Bölümü, Türkiye
Tezin Onay Tarihi: 2012
Öğrenci: BETÜL ÇİLEK
Eş Danışman: SERPİL ŞAHİN, SERVET GÜLÜM ŞÜMNÜ
Özet:The main objective of the study was to encapsulate the phenolic compounds from sour cherry pulp in micro size, to investigate the physicochemical properties of capsules and their digestability in simulated gastric and intestinal fluid. The effect of different coating materials, ultrasonication time and core to coating ratio on encapsulation of phenolic compounds from sour cherry pomace was investigated. Maltodextrin and gum Arabic were chosen as coating materials. Coating material was prepared with different maltodextrin:gum Arabic (MD:GA) ratios of 10:0, 8:2, 6:4 to make the total solid content 10%. In addition, two different core to coating ratios of 1:10 and 1:20 were used. Emulsions were prepared by homogenization through ultrasonication at 160 W power and 20 KHz frequency for different time periods (5-30 min). Then, the emulsions were freeze dried for 48 hours to obtain the microcapsules. Encapsulation efficiency, antioxidant activity, surface morphology, particle size, color, digestability and glass transition temperatures of the microcapsules were determined. The microcapsules with a core to coating ratio of 1:20 were found to have higher encapsulation efficiencies (78.80-92.26%) than those with a core to coating ratio of 1:10 (69.38-77.83%). Increasing the gum Arabic ratio in the coating material increased encapsulation efficiency. Optimum conditions for encapsulation with the highest efficiency and the lowest particle size were sonication time of 22.5 min, MD:GA ratio of 8:2 and core to coating ratio of 1:20. Encapsulation was effective in preventing the release of the phenolic compounds in gastric fluid. On the other hand, phenolic compounds were released from the capsules into the intestinal fluid.