Fehmi Yazici

A note on the total and heme iron contents of ready-to-eat doner kebabs

Total and heme iron contents of ready-to-eat beef and chicken doners collected from restaurants were determined. Total and heme iron contents of beef and chicken doners were 36.70±9.85-15.98±2.86 and 14.27±4.43-4.49±1.95 μg/g, respectively. The percent heme iron contents in beef and chicken doners were 46.06% and 34.36%, respectively.

A Survey on the Some Chemical and Biochemical Properties of Civil Cheese, a Traditional Turkish Cheese

In this article, 15 randomly selected samples of Civil cheese, were purchased from different retail markets in the Erzurum province, Turkey and were investigated for some chemical and biochemical analyses. All cheese samples were analyzed for dry matter, fat, salt, ash, titrable acidity, total nitrogen, soluble nitrogen, ripening index, αs-and β-casein degradation, γ-casein, and peptides. Dry matter, fat, fat in dry matter, salt, salt in dry matter, ash, and acidity values in samples analyzed were found to be as found between 31.33 and 40.12 g/100 g cheese; 1.00 and 7.00 g/100 g cheese; 2.49 and 18.98 g/100 g cheese; 0.11 and 0.34 g/100 g cheese; 0.27 and 1.04 g/100 g cheese; 1.42 and 5.14 g/100 g cheese and, 0.63 and 2.16%, respectively. TN, WSN/TN, TCA-SN/TN, and PTA-SN/ TN values, expressed as TN%, were found between 3.01 and 5.57 g/100 g cheese, 4.25 and 8.80 g/100 g cheese, 3.23 and 6.12 g/100 g cheese, 1.03, and 5.53 g/100 g cheese in Civil cheese samples analyzed, respectively. SDS-PAGE showed that both αs-CN and β-CN ratios were not high compared with similar cheeses, and are not completely hydrolyzed in all Civil cheese samples. A broad range of values from chemical and biochemical analysis indicated that Civil cheeses collected from retail markets lacked standardization. Consequently, it was decided that Civil cheese samples do not undergo an excessive proteolysis.

New approaches to determination of HMF.

Several techniques have been used for hydroxymethylfurfural (HMF) detection in foods. Most of these involve the protein hydrolysation step process to determine the presence of organic acid with heat treatment. The affinity and separability of HMF to/from some proteins were exhibited in this study. Also, the dependency of HMF level was determined in the presence of some substances such as reductive and non-reductive sugars, gums and polysaccharides due to high temperature and acidity during the hydrolysation stage. Consequently, the HMF levels of the samples were evaluated separately either by no treatment or by the acid-heat treated method. The HMF amount which was measured by the conventional method was found to be dependent on the sample amount. The binding capacity of HMF to casein was about 10% but did not bind to the gluten in the model system. However it was not released from the caseine by acid hydrolysation in the solvent.

Natamycin content and quality evaluation of yoghurt from small- and large-scale brands in Turkey.

In this study, the presence of natamycin and quality parameters of yoghurt samples manufactured by small- and large-scale dairy firms in Turkey were investigated. Physicochemical and microbiological results revealed that, except Lactobacillus bulgaricus and Streptococcus thermophilus counts, the majority of the yoghurts manufactured by small-scale dairy firms were found to be out of the limits. Natamycin was detected in 31 and 2 yoghurt samples from small- and large-scale brands, respectively. The levels of natamycin in small-scale brand yoghurts were higher than those in large-scale brand yoghurts. Of the analysed samples, 42.3% did not comply with the Turkish Food Codex.

A Survey on Selected Chemical, Biochemical and Sensory Properties of Kes Cheese, A Traditional Turkish Cheese

Kes, a traditional Turkish dairy product, is commonly produced in the northern Anatolian region of Turkey. Kes samples were obtained from local markets in Ordu vicinity and were investigated for some chemical, biochemical, and sensorial analyses. The mean values of dry matter (DM), fat, fat in DM, salt, salt in DM, ash, and pH were found to be 56.17 ± 6.07, 8.79 ± 2.84, 15.78 ± 5.39, 3.22 ± 1.35, 5.68 ± 2.19, 4.31 ± 1.29 g/100 g cheese, and 4.75 ± 0.59, respectively. The WSN/TN, TCA-SN/TN and PTA-SN/TN values were between 1.79–28.53, 1.67–23.24, and 0.44–17.56%, respectively. SDS-PAGE showed that both αs–CN and β–CN fractions were not completely hydrolyzed in all Kes cheese samples. αs–CN, β–CN, and γ-casein and other peptides fractions determined as 34.57 ± 5.21, 33.74 ± 4.21, and 31.37 ± 6.82%, respectively. Panelists gave high scores (above 7 out of 10) to all samples for all the attributes considered.

Effect of whey pH at drainage on physicochemical, biochemical, microbiological, and sensory properties of Mozzarella cheese made from buffalo milk during refrigerated storage

The objective of this research was to determine the effect of drainage pH on physicochemical, biochemical, microbiological and sensory properties of Mozzarella cheese made from buffalo milk during refrigerated storage. Four vats of cheese were made at 4 different whey drainage pH (6.2, 5.9, 5.6, and 5.2). Lower drainage pH caused higher pH 4.4-soluble N and pH 4.4-soluble N:total N. Interaction of drainage pH at d 1 and 30 of storage on all soluble nitrogen fractions was significant. Degradation of caseins in samples made at a drainage pH of 6.2 was lower than that of other cheese samples. The decreasing whey drainage pH significantly increased counts of thermophilic and mesophilic lactobacilli of the samples during refrigerated storage. No coliforms or Escherichia coli were detected in the cheeses. The average sensory property scores of all cheese samples were very close, and, as expected, storage time had a negative effect on all sensory scores.

Evaluation of the Nutritional and Storage Quality of Meatballs Formulated with Bee Pollen

In this study, the nutritional and storage quality of meatballs formulated with different levels (0, 1.5, 3.0, 4.5 and 6.0%) of bee pollen were investigated during storage at 41℃ for 9 d. Protein content of meatballs increased, while moisture content decreased with increased pollen. The addition of pollen improved cooking loss but decreased the redness (Hunter a value) and sensory scores. Textural parameters (hardness, springsness, gumminess, and chewiness) were affected by pollen addition and the hardness and gumminess values of meatballs decreased as the pollen content increased. While C18:0 content of meatballs slightly decreased with pollen addition, C18:2n-6c, C18:3n-3, C20:5n-3, and PUFA contents increased. The PUFA/saturated fatty acids (P/S) ratio increased from 0.05 in the control to 0.09 in meatballs with 6.0% pollen. The n-6/n-3 ratio decreased from 11.84 in the control to 3.65 in the meatballs with 6.0% pollen. The addition of pollen retarded the lipid oxidation and inhibited the bacterial growth in meatballs. The pH, redness, TBA value and total aerobic mesophilic bacteria, coliform bacteria and S. aureus counts values changed significantly during storage. The results suggest that bee pollen could be added to enhance the nutritional and storage quality of meatballs with minimal changes in composition and/or sensory properties.

Effect of ultrasound treatment on the properties of nano-emulsion films obtained from hazelnut meal protein and clove essential oil

Hazelnut meal protein (4% (w/v)) and clove essential oil (CEO) (3% (v/v)) were homogenized with ultrasound (US) at different times (2, 4 and 6 min) and amplitudes (50, 75 and 100%) to obtain nano-emulsion films. Film forming nano-emulsions (FFNs) were analyzed for average particle size (Dz) and zeta potential, and edible film characterization were evaluated depending on US treatment, as well as antibacterial and antioxidant activities. Dz values and zeta potential of FFNs decreased with increasing acoustic energy delivered to nano-emulsion system. Thickness and water solubility of films significantly decreased with increasing US treatment. Films became more transparent depending on US treatment probably due to particle size reduction. Tensile strength (TS) of films significantly increased with US treatment, while elongation at break (EAB) slightly increased. Microstructure of films became more homogeneous after US treatment and caused to lower water vapor permeability. Enrichment with CEO has given the films antibacterial activity against L. monocytogenes, B. subtilis, S. aureus, P. aeruginosa and E. coli, and antioxidant activity, and US application has improved these activities. US technology can be used to improve mechanical, barrier and antimicrobial properties of hazelnut meal protein based edible films enriched with CEO.

Effect of brewing process and sugar content on 5-hydroxymethylfurfural and related substances from Turkish coffee

ABSTRACT The effect of brewing process on 5-hydroxymethylfurfural, 2-furylmethylketone, and 2-furoic acid levels of traditionally prepared and instant Turkish coffee samples containing different amounts of table sugar (0, 2, 4, or 8 g in 20 mL of coffee) were analyzed by high pressure liquid chromatography with diode array detector. The highest change at the levels of furfurals was observed in sample of traditional and instant Turkish coffee named T4 and S4 both of containing 8 g of sugar, respectively. The results showed that 5-hydroxymethylfurfural, 2-furylmethylketone, and 2-furoic acid concentrations in both traditionally prepared and instant Turkish coffee samples increased with increasing sugar concentration. The brewing method and sugar concentration had a significant effect on furfural contents of Turkish coffee (p < 0.05). Daily intakes of furfurals for Turkish population were calculated as 8.14–13.54 and 9.36–10.25 µg kg−1 body weight for traditionally prepared and instant Turkish coffee samples, respectively, and daily intakes of furfurals were lower than the acceptable daily intake value of 0.5 mg kg−1 body weight.

Toxic and essential elements in butter from the Black Sea region, Turkey

In this study, 88 randomly selected samples of butter produced in the Black Sea region of Turkey were purchased from different retail markets during different periods and investigated for toxic and essential elements content. Quantitative analyses of elements in the samples were performed using an inductively coupled plasma-mass spectroscopy (ICP-MS). Mean concentrations of As, Cr, Cu, Fe, Mn, Ni, Pb, Se and Zn in the butter samples were 18.93, 100.32, 384.66, 4199.1, 887.47, 168.64, 56.13, 16.34 and 384.66 µg kg−1, respectively. Cd and Co were detected in 19 (mean content 0.29 µg kg−1) and 81 (mean content 3.81 µg kg−1) samples of 88 butter samples, respectively. However, the dietary intake of these elements by the population of the Black Sea region is currently well below the dietary reference intake (DRI) and provisional tolerable weekly intake (PTWI) levels of essential and toxic elements.