Effect of extrusion on the functional properties of carrot pulp added extrudates and in-vitro bioaccessibility of lutein and beta-carotene

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Tezin Türü: Yüksek Lisans

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

Tezin Onay Tarihi: 2014

Tezin Dili: İngilizce

Öğrenci: MELDA ORTAK

Asıl Danışman (Eş Danışmanlı Tezler İçin): İlkay Şensoy

Eş Danışman: Zümrüt Ögel

Özet:

In this study, effects of extrusion on the functional properties of carrot pulp added extrudates was investigated. Extrusion was performed at four different conditions. Two different temperature profile and two different screw speeds were investigated. Change in antioxidant activity, phenolic content, β-carotene and lutein content and their in-vitro bioaccessibilities after extrusion were investigated. Antioxidant activity and total phenolic content was determined by DPPH and Folin–Ciocalteu method, respectively. It was found that extrusion process significantly decreased (p≤0.05) the level of both the antioxidant activity and the total phenolic content, but the extrusion temperature and the shear rate did not cause a significant change (p>0.05) within the ranges studied. Effect of conventional heating process on antioxidant activity and phenolic content was also investigated, where no significant changes were observed (p>0.05). The quantification of carotenoids was conducted with HPLC. It is investigated that extrusion process resulted in the loss of β-carotene and lutein content at specified conditions. Extrusion process at 130°C last zone temperature did not affect the lutein in-vitro bioaccessibility while increased the in-vitro bioaccessibility at 160°C (p≤0.05). In-vitro bioaccessibility of β-carotene increased after extrusion both at 130°C and 160°C last treatment zone temperatures