Hasan Temiz

Influence of Wild Garlic on Color, Free Fatty Acids, and Chemical and Sensory Properties of Herby Pickled Cheese

The effect of wild garlic herb (Allium sp.) on color, free fatty acids, chemical and sensorial properties of Herby-Pickled cheese were investigated during ripening. Analyses were carried out on 2, 30, 60, and 90 days of ripening. Increasing of herb level in cheese, L* and b* values of cheese were decreased but, a* values was increased. The color values of all cheese samples changed significantly during ripening. The increase in herb levels in cheese resulted in a significant increase in total free fatty acids value. While the caproic, capric, lauric, myristic, and palmitic acid levels of cheese were significantly increased by herb addition, stearic and oleic acids values significantly decreased. The dry matter, fat, and pH values of control cheeses were found to be higher than those of the others herby cheeses. On the other hand, acidity of control cheese was lower than that of herb added-cheeses. Herb addition only affected significantly body and texture of cheese samples. Sensory scores determined in cheeses during ripening showed significant differences.

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.

Lipid Quality of Anchovy (Engraulis Encrasicholus) Fillets Affected by Different Cooking Methods

The influence of cooking methods (baking, grilling, or frying) on lipid oxidation and fatty acid composition of anchovy (Engraulis encrasicholus) fillets was evaluated. All of the treatments reduced the free fatty acid content of the fillets (P < 0.05) and minimal values were determined in grilled (3.30 g/100 g lipid) and fried (2.84 g/100 g lipid) fillets. The peroxide value and thiobarbituric acid value of the fillets were also increased by the cooking process (P < 0.05). While the maximum peroxide value content of anchovy fillets was determined in grilled fillets as 16.23 meq O2/kg lipid (P < 0.05), the highest thiobarbituric acid values were determined as 3.63 mg MDA/kg fillet and 2.96 mg MDA/kg fillet for grilled and baked fillets, respectively. In the grilled fillets, the increase of thiobarbituric acid value exceeded the permitted limiting value. All of the cooking methods used caused modifications in the fatty acid compositions and only frying caused modification in the n-3/n-6 ratio of the fillets. The modifications in the fatty acid compositions were more prominent in the fried fillets. These results indicated that grilling may be hazardous because of the formation of lipid oxidation products as a result of thermal degradation of lipids during cooking.

The partial purification and properties of pepsin obtained from Turkey proventriculus

In this study, pepsin from turkey proventriculus was purified, and its biochemical properties examined. Initially, the turkey proventriculus (stomach) was mixed with 10% NaCl (1∶2, w/v) and extracted by centrifugation to produce a crude extract. The partial purification of the extract was carried out using Sephadex G-50 resin in gel filtration column chromatography. The fractions obtained by gel filtration were analyzed for milk clotting activity (MCA), protein content, proteolytic activity (PA), purification factor (PF), and SDS-PAGE electrophoresis was also performed. The enzyme was purified 207-fold with a recovery of 36%. The first 4 fractions did not have any activities; fractions 7, 8, and 9 exhibited the highest levels of milk clotting and proteolytic activity. The electrophoretic patterns revealed that further purification steps should be applied for better results.

Composition of volatile aromatic compounds and minerals of tarhana enriched with cherry laurel (Laurocerasus officinalis)

Different concentrations of cherry laurel pulp (0, 5, 10, 15 and 20%) were used to produce tarhana samples. Volatile aromatic compounds and minor mineral content were investigated. Volatile aromatic compounds were analyzed by using GC–MS with SPME fiber and minor mineral values were evaluated with inductively coupled plasma optical emission spectrometer. The statistical analysis showed that addition of pulp affected volatile aromatic compounds and minor mineral content significantly. Thirty five volatile aromatic compounds were found in tarhana samples. The octanoic acid from acids, benzaldehyde (CAS) phenylmethanal from aldehydes, 6-methyl-5-hepten-2-one from ketones, octadecane (CAS) n-octadecane form terpenes, ethyl caprylate from esters and benzenemethanol (CAS) benzyl alcohol from alcohols had the highest percentage of volatile aromatic compounds. Tarhana samples were rich source of Mn, Cu and Fe content.

Partial purification and characterization of alkaline proteases from the Black Sea anchovy (Engraulis encrasicholus) digestive tract

Alkaline proteases from the digestive tract of anchovy were partially purified by ammonium sulfate fractionation, dialysis and Sephadex G-75 gel filtration. The purification fold and yield were 6.23 and 4.49%, respectively. The optimum activities of partially purified alkaline proteases were observed at 60°C and at pH 11.0. The alkaline proteases were stable within the temperature range of 40 to 50°C and pH range of 9.0 to 11.0. They were inhibited by the serine-protease inhibitor phenylmethylsulfonyl fluoride (PMSF) and trypsin specific inhibitor benzamidine, but were not inhibited by the β-mercaptoethanol. The enzymes were slightly activated by metal ions such as Na + and Ba 2+ and inhibited by Cu 2+ , Zn 2+ , K + and Mn 2+ at different degrees. The molecular weight of the partially purified enzyme was 24 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Key words : Alkaline proteases, Engraulis encrasicholus , purification, characterization, digestive tract.