Aziz Tekin

Utilization of zero-trans non-interesterified and interesterified shortenings in cookie production

The effects of zero-trans chemically interesterified (in-es) and non-interesterified (non-in-es) cottonseed (CO), hazelnut (HO) and olive oil (OO) and their blends (25, 50 and 75%) with palm oil (PO) were studied in the production of cookies. All the experimental shortenings had zero-trans fatty acids (TFA) while the shortening contained 14.20% TFA. Incorporation of CO in PO considerably increased the linoleic acid content whereas the raising of HO and OO ratio in the blend increased the oleic acid content. Zero-TFA and lower saturated /unsaturated fatty acid ratio (SFA/UFA) of some of the experimental shortenings indicated an important in nutritional properties of cookies produced from these experimental shortenings. Cookies with in-es shortenings showed significantly higher (p < 0.05) spread ratios and L Hunter color than their non-in-es shortenings added counterparts. It can be concluded that chemical interesterification is a promising method to produce cookie shortenings with zero-TFA.

Production of Microfluidized Wheat Bran Fibers and Evaluation as an Ingredient in Reduced Flour Bakery Product

In this study, the potential use of microfluidization as a milling process for wheat bran was evaluated. More specifically, the influences of regular wheat bran and microfluidized wheat bran on quality (hardness, cutting force, specific volume, and color) and storage characteristics of model bakery product cake were compared. Microfluidization process led to formation of the finely separated fibrous structure with great surface area that allowed higher water holding capacity and methanol soluble-free phenolic content. Rheological measurements showed that the increased surface area of fibers also allowed bran fiber to intertwine and form strong fibrous matrix resulting in higher consistency index, yield stress, and viscoelastic moduli values in batter samples. Various flour formulations have been also tested in the presence of microfluidized wheat bran, and in reduced flour-containing samples, a fibrous network provided gluten-like strength to the batter and cake samples. Microfluidized wheat bran also affected color of cake samples. High water holding ability of microfluidized wheat bran had also impact on moisture loss and staling rate of the cake samples. These results show that microfluidized wheat bran could be an alternative functional ingredient in bakery products.

A novel mutation of ABCG5 gene in a Turkish boy with phytosterolemia presenting with macrotrombocytopenia and stomatocytosis.

Phytosterolemia is a rare autosomal recessive sterol storage disease caused by mutations in ABCG5 and ABCG8 genes. A 9‐year‐old Turkish boy who was presented with exclusively hematologic abnormalities had elevated plant sterol levels. Sequencing of ABCG5 and ABCG8 genes revealed a novel homozygous IVS10‐1 G>T mutation in ABCG5 gene. Four of the 13 family members had xanthoma but they had neither hematologic abnormalities nor IVS10‐1 G>T mutation. Ezetimibe therapy reduced plant sterol levels in association with marked clinical improvement. Plant sterol levels and ABCG5/ABCG8 genes should be analysed in patients with unexplained hemolytic anemia and macrothrombocytopenia. Pediatr Blood Cancer 2014; 61:1457–1459.

Effect of Ozonated Water Treatment on Fatty Acid Composition and Some Quality Parameters of Olive Oil

ABSTRACT The organic olives from Çine-Aydın (Turkey) were washed with tap or ozonated water for 2 and 5 min, respectively, and pressed to olive oil. The effects of wash treatments on fatty acid composition and several quality parameters of the oils were determined. The maximum values after 2-min ozonated water washes were 9.58 meqO2/kg, 0.73%, 2.44 and 0.16 for peroxide, free acid, K232 and K270 values, respectively, which were under the standard limits for extra-virgin olive oil. Five min of ozonated water washes also yielded acceptable results, except for a slight excess on K232 value. Ozonated water washes had almost no effect on fatty acid composition.

Multi-objective Optimization of Molecular Distillation Conditions for Oleic Acid from a Rich-in-Fatty Acid Model Mixture

Oleic acid is a commercially valuable compound and has many positive health effects. Determining optimum conditions in a physical separation process is an industrially significant point due to environmental and health related concerns. Molecular distillation avoids the use of chemicals and adverse effects of high temperature application. The objective of this study was to determine the molecular distillation conditions for oleic acid to increase its purity and distillation yield in a model fatty acid mixture. For this purpose, a short-path evaporator column was used. Evaporation temperature ranged from 110 to 190℃, while absolute pressure was from 0.05 to 5 mmHg. Results showed that elevating temperature generally increased distillation yield until a maximum evaporation temperature. Vacuum application also affected the yield at a given temperature, and amount of distillate increased at higher vacuums except the case applied at 190℃. A multi-objective optimization procedure was then used for maximizing both yield and oleic acid amounts in distillate simultaneously, and an optimum point of 177.36℃ and 0.051 mmHg was determined for this purpose. Results also demonstrated that evaporation of oleic acid was also suppressed by a secondary dominant fatty acid of olive oil - palmitic acid, which tended to evaporate easier than oleic acid at lower evaporation temperatures, and increasing temperature achieved to transfer more oleic acid to distillate. At 110℃ and 0.05 mmHg, oleic and palmitic acid concentrations in distillate were 63.67% and 24.32%, respectively. Outcomes of this study are expected to be useful for industrial process conditions.

Oxidative changes in hazelnut, olive, soybean, and sunflower oils during microwave heating

ABSTRACT The effects of microwave heating for 3, 6, and 9 min at a frequency of 2450 MHz on fatty acid composition, tocopherols, iodine value, free fatty acids (%), peroxide value, conjugated dienes and trienes, and hexanal contents of refined hazelnut, soybean, sunflower, and virgin olive oils were investigated. A significant (p < 0.05) decrease was observed in linoleic and linolenic acids contents of soybean oil during exposure to microwave heating. Tocopherol contents of oil samples significantly decreased (p < 0.05) during microwave heating. Free fatty acids of the samples slightly increased and iodine value showed reduction throughout the process. Conjugated dienes contents of samples showed an increasing trend up to the 6 min, followed by a reduction at 9 min. Conjugated triene fatty acids of all the samples significantly increased (p < 0.05) throughout the application. While peroxide value showed increasing trend up to the 3 min and sharply decreased at 9 min, hexanal contents of refined hazelnut, virgin olive, soybean, and sunflower oils increased 63, 28, 55, and 389 fold, respectively, after 9 min exposure to microwave heating. Kinetic analysis of data showed that the reaction orders for peroxide and hexanal formation were zero and first order, respectively, and in the tested oils the reaction rate followed the order: soybean oil ˃ sunflower oil ˃ hazelnut oil ˃ virgin olive oil for peroxide, and sunflower oil ˃ soybean oil ˃ hazelnut oil ˃ virgin olive oil for hexanal formation. It was concluded that hexanal could be considered as a parameter for evaluation of the quality of oils exposed to microwave heating.

Different sized wheat bran fibers as fat mimetic in biscuits: its effects on dough rheology and biscuit quality

The aim of this study is to investigate the effects of various particle sized and different amount of plant fibers as fat mimetic for biscuit formulations instead of biscuit fat. The fibers with different particle sizes were obtained from wheat bran and used instead of fat in biscuit formulations. The texture, rheology and quality analyses of low-fat biscuit (30, 20 and 10% fat) were performed and compared with those of the full-fat control sample (40% fat). Results showed that wheat bran fiber with bigger particle size (Long Fiber, LF) were more favorable in terms of textural properties of the dough and the quality parameters of biscuits while the fibers with smaller particle size (Medium Fiber, MF and Small Fiber, SF) improved viscoelastic properties of dough similar to the control. Although the use of these fibers in the production of low-fat biscuits were suitable in terms of workability of dough increasing fiber content and/or reducing fiber size resulted in harder biscuits with lower spread ratio. This study showed that the texture of biscuits was greatly dependent on the texture of the dough.

THE EFFECT OF MALAXATION TIME AND TEMPERATURE ON SOME PROPERTIES OF OLIVE OIL

The aim of the study was to determine the effect of different malaxation time (30, 60 and 90 min) and temperatures (30, 45 and 60°C) on quality criteria and oxidative stability of Edremit yağlık and Memecik olive oils. For this purpose, olives from Edremit yağlık and Memecik varieties were subjected to crushing, malaxation, pressing and centrifugation operations in laboratory scale and extra virgin olive oils were obtained. Results demonstrated that free fatty acidity, peroxide value and total phenol content of Memecik olive oil were higher than Edremit yağlık variety, whereas K232 and K270 values and induction periods of Edremit yağlık olive oil were higher than Memecik olive oil. The effect of malaxation time and temperature was not influential on free fatty acidity, K 232 and K270 values and total phenol content of olive oils. On the other side, a slight increase in peroxide value was determined when malaxation time was increased. The increase in malaxation temperature led to an increase in induction period of olive oils. On the other hand, there was no significant effect of malaxation conditions on the fatty acid compositions of olive oils.

AYÇİÇEK ve PİRİNA YAĞLARININ KIZARTMA STABİLİTELERİNİN KARŞILAŞTIRILMASI

Calismanin amaci, aycicek ve pirina yaglarinin kizartma stabilitelerinin karsilastirilmasidir. Materyal olarak rafine aycicek yagi ile pirina-rafine pirina karisimi (50:50) kullanilmistir. Patatesle yapilan kizartma islemleri 180 o C’de 3 dakika olarak gerceklestirilmis ve toplamda 40 kizartma yapilmistir. Kizartma islemleri boyunca yaglarda serbest yag asitleri, dumanlanma noktasi, p -anisidin, toplam polar madde, viskozite, polimer trigliserit ve renk analizleri yapilmistir. Yaglarda serbest yag asitleri, p-anisidin, toplam polar madde, viskozite, polimer trigliserit ve renk degerlerinde artis, dumanlanma noktasi degerlerinde ise azalma gozlenmistir. Pirina yaginin dumanlanma noktasi aycicek yagina gore daha kisa surede 170°C’den daha dusuk bir degere ulastigi gorulmustur. Buna karsin olusan polimer trigliserit ve buna bagli olarak gerceklesen viskozite degerlerindeki artislar, pirina yaginda aycicegi yagina gore oldukca dusuk degerlerdedir. Tum incelenen degerler arasindaki farkliliklar incelendiginde, pirina yaginda elde edilen degerlerin, aycicegi yagina oranla daha dusuk kaldigi belirlenmistir. Bu sonuclar, doymamislik derecesi dusuk olan pirina yaginin kizartma islemleri sirasinda bozulma reaksiyonlarina daha dusuk duzeyde maruz kaldigini gostermektedir.

GÜNEYDOĞU ANADOLU BÖLGESİ’NDE YETİŞTİRİLEN GEMLİK ÇEŞİDİ ZEYTİNLERDE VERTİCİLLİUM SOLGUNLUĞUNUN ZEYTİNYAĞI KALİTE PARAMETRELERİ VE FENOLİK BİLEŞENLERE ETKİSİ

Calismanin amaci Verticillium solgunlugunun zeytinyagi kalite parametreleri ve fenolik bilesenlerine etkisini incelemektir. Bu amacla, Guneydogu Anadolu Bolgesi’nde yetistirilen Gemlik cesidine ait 16 farkli ornek degisik yetisme alanlarindaki enfekte agaclardan hasat edilmistir. Zeytinler, hastalik siddetine gore siniflanmis ve su, yag ve fenolik iceriklerine gore degerlendirilmistir. Zeytin ornekleri laboratuvar olcekli bir sistemle yaga islenmis ve ornekler serbest yag asitleri; peroksit degeri; K 232 , konjuge dien ve ΔE degerleri ile toplam fenol ve fenolik bilesen dagilimi acisindan analiz edilmislerdir. Sonuclar, hastalik siddetiyle zeytinlerin su iceriginin dustugunu fakat yag iceriginin degismedigini gostermistir. Peroksit, K 232, konjuge dien, ΔE degerleri ve toplam fenol miktari hastalik siddetiyle genellikle pozitif korele iken, serbest yag asitleri degismemistir. Zeytinyagi orneklerinin hakim fenoligi luteolin olup, trans sinnamik asit ve luteolin-7-glikozit izleyen fenolikler olarak tespit edilmistir.