This study aimed to detect the fatty acid profile and oxidative stability traits of hazelnuts dried using three different methods: artificial drying (AR), concrete ground (CN), and grass ground (GS) during 12 months of storage (2013–2014) at 20–25°C and 70–90% relative humidity. As expected, monounsaturated fatty acids (MUFA) were the main fatty acid group (81.75–83.59%) followed by polyunsaturated fatty acids (10.20–11.48%) and saturated fatty acids (5.38–6.96%). Samples dried in AR had more MUFA (83.59%) than sun-dried (CN and GS) samples. Following the drying process, the lowest peroxide value (PV) and the highest ratio of oleic-to-linoleic acid (8.27%) were recorded in samples dried in AR. At the end of storage, the PV was lower in samples dried in AR than on CN and GS methods. The results of this research showed that the AR method is the best for drying hazelnut. This research, therefore, recommends the AR method for drying hazelnuts on a commercial scale.

The aim of this study was to investigate the effects of different cooking techniques and internal cooking temperature applications on the oxidative stability of hamburger patties. For this purpose, 4 different cooking techniques (boiling, oven-roasting, grilling and microwave) and 2 different internal cooking temperatures (72°C and 78°C) were used. Microwave cooking caused the highest cooking loss values. The higher cooking loss values were determined as a result of the 78°C internal cooking temperature application. Lower pH values were obtained by microwave cooking. Boiling increased L* and a* values, whereas decreased b* values compared to other cooking techniques. While a* values decreased with storage in hamburger patties, b* and HUE angle values increased. The lower thiobarbituric acid reactive substances (TBARS) and lipid hydroperoxide (LPO) values were determined in samples cooked with microwave or boiling technique. Even though there was no TBARS difference between different internal cooking temperature applications, the higher LPO values were determined in the application of 78°C internal cooking temperature. The results of this study showed that less oxidative changes could be occurred by the use of either microwave or boiling technique in hamburger patty production.

Çalışmanın amacı Çekişte çeşidi zeytinlerden elde edilen zeytinyağlarının ısıtma işlemi sırasında temel kalite kriterleri, oksidatif stabilite ve yağ asidi bileşiminde meydana gelen değişimlerin belirlenmesidir. Bu amaçla Aydın ilinden 2017 yılında hasat edilmiş olan Çekişte çeşidi zeytinlerden elde edilmiş olan zeytinyağı, 100°C sıcaklıkta ve 20 L/saat hava akışı altında toplamda 50 saat süreyle ısıtılmıştır ve 10 saatlik aralıklarla serbest yağ asidi oranı, peroksit sayısı, dien ve trien (K232 ve K270) değerleri, toplam fenol miktarı, antioksidan aktivite, klorofil ve karotenoid miktarları ile yağ asidi kompozisyonları yönünden analiz edilmiştir. Ayrıca örneklerin indüksiyon periyodu olarak ifade edilen oksidatif stabiliteleri belirlenmiştir. Çalışma sonunda temel kalite parametrelerinden serbest yağ asidi miktarı, peroksit sayısı, dien ve trien (K232 ve K270) değerlerinin ısıtma işlemi ile birlikte artış gösterdiği saptanmıştır. Örneklerin toplam fenol, antioksidan aktivite, klorofil ve karotenoid miktarları ise ısıtma süresinin artmasıyla birlikte kademeli olarak azalmıştır. Benzer şekilde indüksiyon periyodunun da işlem süresinin artmasıyla birlikte azaldığı tespit edilmiştir. Zeytinyağı örneklerinde tespit edilen yağ asitlerinden linolenik asit miktarının ise işlem sonunda önemli düzeyde arttığı, oleik asit miktarının ise işlem öncesine göre azalma eğiliminde olduğu saptanmıştır.

This study aimed to detect the fatty acid profile and oxidative stability traits of hazelnuts dried using three different methods: artificial drying (AR), concrete ground (CN), and grass ground (GS) during 12 months of storage (2013–2014) at 20–25°C and 70–90% relative humidity. As expected, monounsaturated fatty acids (MUFA) were the main fatty acid group (81.75–83.59%) followed by polyunsaturated fatty acids (10.20–11.48%) and saturated fatty acids (5.38–6.96%). Samples dried in AR had more MUFA (83.59%) than sun-dried (CN and GS) samples. Following the drying process, the lowest peroxide value (PV) and the highest ratio of oleic-to-linoleic acid (8.27%) were recorded in samples dried in AR. At the end of storage, the PV was lower in samples dried in AR than on CN and GS methods. The results of this research showed that the AR method is the best for drying hazelnut. This research, therefore, recommends the AR method for drying hazelnuts on a commercial scale.