Food Engineering / Gıda Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/12
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Conference Object Citation - WoS: 14Citation - Scopus: 16Drying of Olive Leaves in a Geothermal Dryer and Determination of Quality Parameters of Dried Product(Elsevier, 2019) Helvacı, Hüseyin Utku; Menon, Abhay; Aydemir, Levent Yurdaer; Korel, Figen; Gökçen Akkurt, GüldenIn this study, a cabinet type geothermal dryer was designed, operated and tested for drying olive leaves with minimum losses of phenolic content and antioxidant capacity by optimization of drying conditions. Two factors; face centered central composite design was applied and response surface methodology was used to optimize the drying conditions of olive leaves. The results indicate that phenolic content stability were mainly affected by air temperature, whereas antioxidant capacity is affected by both air temperature and velocity (p<0.05). The optimal drying conditions were found to be at 50°C of air temperature and 1 m/s of air velocity for the minimum losses of determined quality parameters, where 88.8% of phenolic content and 95.3% of antioxidant capacity were recovered.Article Citation - WoS: 49Citation - Scopus: 66Bioactive, Functional and Edible Film-Forming Properties of Isolated Hazelnut (corylus Avellana L.) Meal Proteins(Elsevier Ltd., 2014) Aydemir, Levent Yurdaer; Adan Gökbulut, Aysun; Baran, Yusuf; Yemenicioğlu, AhmetThis study aimed characterization of bioactive, functional and edible film making properties of isolated proteins from untreated (HPI), hot extracted (HPI-H), acetone washed (HPI-AW), and acetone washed and hot extracted (HPC-AW-H) hazelnut meals. The most bioactive protein extract was HPC-AW-H, followed by HPI-AW, HPI-H and HPI, based on antioxidant activity (TEAC and ORAC: 158-461mmolTrolox/kg), iron chelation (60.7-126.7mmolEDTA/kg), angiotensin-converting enzyme inhibition (IC50: 0.57-1.0mg/mL) and antiproliferative activity on colon cancer cells (IC50: 3.0-4.6mg/ml). Protein contents of HPI, HPI-H and HPI-AW (93.3-94.5%) were higher than that of HPC-AW-H (86.0%), but HPC-AW-H showed the best pH-solubility profile. The extracts showed good oil absorption (7.4-9.4g/g) and foaming, but limited water holding and gelling capacities, and emulsion stability. The protein extracts gave transparent, yellowish to brownish and reddish colored and water soluble edible films. The HPI gave the lightest colored films with acceptable mechanical properties (elongation up to 144% and tensile strength up to 4.9MPa). 1-D and 2-D electrophoresis clearly showed the molecular and isoelectric profiles of hazelnut proteins. The overall results of this study showed that the bioactive, solubility and gelation properties of hazelnut proteins could be improved by simple processes like acetone washing and/or heat treatment. The hazelnut proteins are valuable as multipurpose food ingredients.Article Citation - WoS: 104Citation - Scopus: 123Potential of Turkish Kabuli Type Chickpea and Green and Red Lentil Cultivars as Source of Soy and Animal Origin Functional Protein Alternatives(Academic Press Inc., 2013) Aydemir, Levent Yurdaer; Yemenicioğlu, AhmetIn this study, functional properties of proteins from Turkish Kabuli type chickpea (CPEs) and green and red lentil cultivars (LPEs) were characterized and compared with those of soy and animal proteins. The LPEs and whey protein isolate (WPI) showed higher soluble and total protein content than the other proteins. CPEs showed the highest oil absorption capacity (10.9-14.59 g/g), followed by LPEs (6.90 -10.44 g/g), soy protein extract (8.23 g/g), and egg white proteins (6.37 g/g). The highest water absorption capacities were obtained for bovine gelatin (BGEL) (8.84 g/g), CPEs (4.90-7.94 g/g) and soy protein isolate (7.94 g/g). The foaming capacities of BGEL and fish gelatin (FGEL), and emulsifying capacity of WPI were slightly higher than those of CPEs and LPEs, but most stable emulsions and foams were formed by chickpea and lentil proteins. The least gelling concentration of CPEs (5-7 g/100 g) came second after BGEL (3 g/100 g). The 2-D electrophoresis revealed the detailed isoelectric point (between 4.5 and 5.9) and molecular weight patterns of chickpea and lentil proteins. This study clearly showed that the functional properties of Kabuli chickpea proteins are superior than those of lentil proteins and most of the studied soy and animal proteins.Article Citation - WoS: 76Citation - Scopus: 85Development of Flexible Antimicrobial Packaging Materials Against Campylobacter Jejuni by Incorporation of Gallic Acid Into Zein-Based Films(American Chemical Society, 2011) Alkan, Derya; Aydemir, Levent Yurdaer; Arcan, İskender; Yavuzdurmaz, Hatice; Atabay, Halil İbrahim; Ceylan, Çağatay; Yemencioğlu, AhmetIn this study, antimicrobial films were developed against Campylobacter jejuni by incorporation of gallic acid (GA) into zein-based films. The zein and zein-wax composite films containing GA between 2.5 and 10 mg/cm 2 were effective on different C. jejuni strains in a concentration-dependent manner. Zein and zein-wax composite films showed different release profiles in distilled water but quite similar release profiles at solid agar medium. Depending on incorporated GA concentration, 60-80% of GA released from the films, while the remaining GA was bound or trapped by film matrix. The GA at 2.5 and 5 mg/cm 2 caused a considerable increase in elongation (57-280%) of all zein films and eliminated their classical flexibility problems. The zein-wax composite films were less flexible than zein films, but the films showed similar tensile strengths and Young's modulus. Scanning electron microscopy indicated different morphologies of zein and zein-wax composite films. This study clearly showed the good potential of zein and GA to develop flexible antimicrobial films against C. jejuni.