Muhammet Dervisoglu

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.

Manufacture and characterization of kefir made from cow and buffalo milk, using kefir grain and starter culture.

The microbiological and chemical characteristics as well as organic and amino acid profiles of kefir samples made from cow and buffalo milks fermented by kefir grains and starter culture were investigated during storage for 21 d at 4°C. After incubation, lactic, acetic, and citric acid concentrations showed a difference among the samples due to milk type and production methods. Storage time had little effect on the organic acid values of kefir samples. As compared with cow milk kefir, buffalo milk kefir had higher numbers of microorganisms, except lactobacilli, at the end of storage. Whereas pH and titratable acidity exhibited similar changes during storage in all kefir samples, ethanol levels were significantly increased in buffalo milk kefir samples. Glutamic acid was the major amino acid at all sampling times for all samples. Tyrosine, serine, histidine, alanine, methionine, and lysine concentrations were determined to be different in all samples depending on milk type. In general, due to the higher microbial population (especially yeast), kefir made from buffalo milk may be preferred.

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.

Occurrence of Aflatoxin M1 in Vacuum Packed Kashar Cheeses in Turkey

In this study, aflatoxin M1 (AFM1) levels of vacuum packed Kashar cheese marketed in the Black Sea Region of Turkey were determined during October 2008 and June 2009. The occurrence of AFM1 contamination in vacuum packed cheese samples was investigated using immunoaffinity column extraction and high-performance liquid chromatography. AFM1 was detected in 144 (97.96%) of cheese samples ranging from 0.015 to 3.774 μg/kg cheese, and mean value of AFM1 was found to be 0.273 μg/kg cheese. AFM1 level in 16 (11.11%) of positive samples was higher than the maximum tolerance limit (0.5 μg/kg) accepted by Turkish Food Codex.

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.

Influence of an ultrasonic nozzle in spray‐drying and storage on the properties of blueberry powder and microcapsules

BACKGROUND Recently, ultrasonic nozzle technology has been applied in spray-drying because of its numerous advantages, including providing more uniform droplets and reducing damage observed in bioactive compounds. In this study, the production of blueberry powders and microcapsules by using an ultrasonic spray nozzle was investigated. Firstly, the important ultrasonic nozzle parameters were optimised by using response surface methodology and compared with a conventional nozzle (control). Secondly, powder and microcapsules obtained at the optimum point were stored at 22 °C and 35 °C at 0.32 water activity (aw ). RESULTS The optimum conditions were estimated as 125 °C inlet air temperature, 9 W ultrasonic power and 8% feed pump rate. There was significantly difference (P < 0.05) in the total phenolic content and antioxidant power of microcapsules produced by an ultrasonic nozzle and a conventional nozzle. Because the temperature affected the stability of powders negatively, the blueberry powder showed higher losses than microcapsules in the content of bioactive compounds. In addition, the ultrasonic nozzle showed a significantly greater protective effect on physico-chemical properties than did the conventional nozzle. CONCLUSION Results of the study point that the production of ultrasonic nozzle powders and microcapsules is feasible to use as a functional ingredient in food industry.

Antifungal activity of lemon balm and sage essential oils on the growth of ochratoxigenic Penicillium verrucosum

In this study, the chemical compositions of essential oils (EOs) from lemon balm ( Melissa officinalis ) and sage ( Salvia officinalis ) were determined using gas chromatography/mass spectrometry (GC/MS) method, indicating that 1,2-propanediol (31.26%) and α-thujone (24.92%) were the major components in lemon balm and sage, respectively. In addition, antifungal effects of these EOs against ochratoxigenic Penicillium verrucosum Dierckx (D-99756) isolated from Kashar Cheese were investigated. In order to test their antifungal effects, the EOs dilutions were prepared in methanol at seven different concentrations (500, 250, 125, 62, 31, 15.5 and 7.75 µl/ml; the values corresponding to 0.5, 0.25, 0.125, 0.062, 0.031, 0.015 and 0.00775% based on agar medium). Their antifungal activities were determined with respect to minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC). The MIC values of lemon balm and sage EOs against P. verrucosum were determined to be the 125 and 62 µl/ml, respectively; and their MFC values were found to be 250 and 125 µl/ml, respectively, indicating that sage exhibited two fold fungistatic and fungicidal effect against ochratoxigenic P. verrucosum than did lemon balm. The results of this study suggest that lemon balm and sage EOs can be considered as natural antifungal agents that can be used to inactivate ochratoxigenic P. verrucosum with respect to food safety applications.

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.