Akademik Veri Yönetim Sistemi
Tezin Türü: Yüksek Lisans
Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Gıda Mühendisliği Bölümü, Türkiye
Tezin Onay Tarihi: 2014
Öğrenci: ELİF YILDIZ
Eş Danışman: ALEV BAYINDIRLI, BEHİÇ MERT
Özet:The main objective of this study was to investigate the effect of micro and nano hazelnut skin fibers on biscuit quality, texture, and staling. In the first part of the study, microstructural properties of cacao powder and hazelnut skin samples and rheological, and textural properties of biscuit dough containing different percentages (0%, 10%, 15%, and 20%) of cacao powder or hazelnut skin samples were observed. Flow behaviors of biscuit dough was explained with power law model and shear thinning behavior was observed. Also, elastic and viscous moduli of biscuit dough were evaluated and it was found that the highest elastic modulus and viscous modulus were obtained from dough containing 20% microfluidized hazelnut skin fibers. Moreover, the effects of replacement of flour by cacao powder or hazelnut skin samples on quality of biscuits (moisture content, size, color, and hardness) were determined. The darkest color and the highest moisture content was obtained from biscuits containing 20% microfluidized hazelnut skin fiber. The lowest spreading ratio was also observed in this sample. Breaking strength increased with increasing percentage of cacao powder or hazelnut skin samples in biscuit samples. In the second part of this study, staling of biscuit samples was analyzed with X-ray, FT-IR and other quality parameters. Slow starch retrogradation was achieved in biscuits prepared with microfluidized hazelnut skin fiber. It means that staling of biscuits was retarted. In the last part of this study, phenolic content of cacao powder and hazelnut skin samples were analyzed. The highest value was observed for microfluidized hazelnut skin fiber.