Browsing by Author "Aydemir, Levent Yurdaer"

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Citation - WoS: 46
Bioactive, functional and edible film-forming properties of isolated hazelnut (Corylus avellana L.) meal proteins
(Elsevier Sci Ltd, 2014) Aydemir, Levent Yurdaer; Gokbulut, Aysun Adan; Baran, Yusuf; Yemenicioglu, Ahmet; Baran, Yusuf
This 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: 158-461 mmol Trolox/kg), iron chelation (60.7-126.7 mmol EDTA/kg), angiotensin-converting enzyme inhibition (IC50: 0.57-1.0 mg/mL) and antiproliferative activity on colon cancer cells (IC50: 3.0-4.6 mg/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 (7.4-9.4 g/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 4.9 MPa). 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. (c) 2013 Elsevier Ltd. All rights reserved.
Characterization of antioxdant activity and protein functionality in some legume cultivars grown in Turkey
(Izmir Institute of Technology, 2008) Aydemir, Levent Yurdaer; Yemenicioğlu, Ahmet
Turkish chickpeas (4 cultivars) and lentils (6 cultivars) show similar total phenolic contents and free radical scavenging capacities in aqueous extracts ranging between 2869 and 4312 mg gallic acid equivalents/kg legume and 24.42 and 38.20 mmol Trolox equivalents/kg legume, respectively. However, the free radical scavenging capacity of lentil and chickpea protein extracts, range between 110 and 185 mmol Trolox/kg protein and 58 and 144 mmol Trolox/kg protein, respectively, clearly showed the higher free radical scavenging capacity of lentil proteins than chickpea proteins.Protein extracts of chickpeas and lentils showed considerable emulsifying and foaming capacities in almost at the same range, but emulsions and foams formed by chickpea proteins are more stable than those of lentil proteins. The lentil protein extracts are highly soluble and showed poor water absorption and gelling characteristics. In contrast, chickpea protein extracts showed moderate water absorption and gelling capacity.Chickpea protein extracts are also good oil absorbers with almost 1.5 to 2 fold better oil adsorption capacity than lentil protein extracts. Thus, chickpea proteins are suggested as soy and whey protein alternatives for functional proteins used in the food, drug and cosmetics industries. Considering functional properties of proteins for different cultivars, the outstanding Turkish chickpea cultivars are Gökçe and Cevdetbey, while the outstanding Turkish lentil cultivar is Alidayı. Variations in the functional properties of protein suggest the diversity of genes in chickpeas and lentils responsible for these properties. Thus, this study showed the possibility of improving functional properties of chickpeas and lentils by breeding programs.
Production of high quality functional proteins from legumes and plant based agroindustrial wastes and byproducts
(Izmir Institute of Technology, 2014-07) Aydemir, Levent Yurdaer; Yemenicioğlu, Ahmet
In this thesis, technological and bioactive properties of protein concentrates and isolates form Turkish lentil and chickpea cultivars and hazelnut meal has been characterized. This study aimed to increase industrially suitable alternatives to soy and animal origin proteins. The functional properties (solubility, gelation, water and oil absorption, emulsion and foaming capacity and stability) of globulin proteins from chickpeas are comparable or superior than those of soy proteins and most animal proteins (fish and bovine gelatin, egg white and whey proteins) with the exception of gelation capacity of bovine gelatin. The chickpea proteins got extremely high water (4.9-7.9 g/g) and oil (10.9-14.6 g/g) absorption capacity. The lentil globulins showed high protein solubility (0.56-0.69 g/g) and oil absorption capacities (6.9-10.4 g/g), but missed water absorption and gelation properties. The lentil proteins showed 2-3 fold higher antioxidant capacity than the chickpea proteins, and antioxidant lentil protein fractions could be separated or concentrated by isoelectric precipitation, ion exchange chromatography and ultrafiltration. The hazelnut meal globulins showed satisfactory oil absorption (7.4-9.4 g/g) and good foaming (7.1 to 18.9 ml foam with 10 mg/ml), but poor water absorption, gelation and emulsion properties. The hazelnut proteins also form water soluble yellowish to brownish and reddish colored transparent edible films with 10-12.5 % (w/w) solutions. However, the most outstanding properties of hazelnut meal proteins is their high bioactivity including free radical scavenging (158-461 μmol Trolox/g), iron chelation (60.7-126.7 μmol EDTA/g) and angiotensin-converting enzyme inhibition (IC50: 0.57-1.0 mg/mL) capacities. Thus, a functional beverage, hazelnut milk enriched with trypsin and pepsin hydrolyzed hazelnut globulins, was developed as an example functional food product. This work showed the good potential of selected Turkish plant resources as animal and soy protein alternatives.