Ion Chromatographic Determination of Free Cyanide in Different Classes of Bottled Natural Mineral Water Consumed in Turkey

An ion chromatographic method for the quantitative determination of free cyanide in bottled natural mineral waters were measured in terms of selectivity, linearity, the limit of detection, limit of quantification, repeatability, precision, and accuracy. Chromatographic separation of free cyanide ions was accomplished with an anion-exchange column and detected by pulsed amperometric detection with a silver working electrode. The method was found to be selective, linear (r² = 0.999) at a concentration range of 0.5 to 134 μg L^?1, precise, and accurate. Recovery values of free cyanide in all classes of natural mineral water varied from 65.9 ± 1.6 to 95.2 ± 0.7 at different spiking levels (5–70 μg L^?1). Parameters (total dissolved solids, mineral interferences, and added sodium hydroxide) affecting the recovery values were studied in this project. The limit of detection and limit of quantification were found to be 0.295 and 0.983 μg L^?1, respectively. The proposed method was applied to 27 different brands of commercially available bottled natural mineral water products sold in Turkish markets. These natural mineral waters were classified as: (i) very low mineral concentration, (ii) low mineral concentration, (iii) intermediate mineral concentration, and (iv) high mineral concentration based on their total dissolved solids contents according to European Union Directive (Directive 80/777/EEC). Levels of free cyanide residues in the samples ranged from > limit of detection to 6.12 μg L^?1. The highest average concentration of free cyanide residues was found in the class of “high mineral concentration waters.” However, the determined free cyanide values in all of the tested natural mineral water samples were found to be within the limits of European Union legislation.     

Kinetic and thermodynamic investigation of mancozeb degradation in tomato homogenate during thermal processing

BACKGROUND: The kinetic and thermodynamic parameters of mancozeb degradation in tomato homogenates under the conditions prevailing in the manufacture of tomato products (at 60–100 °C for 0–60 min) were investigated. A gas chromatography–mass spectrometry method was used to analyse residual mancozeb in tomato homogenate. Ethylenethiourea (ETU), the main toxic degradation product of mancozeb, was measured by high‐performance liquid chromatography (HPLC)–with photodiode array detector (PDA). RESULTS: The degradation of mancozeb and the formation of ETU in tomato homogenates were adequately described as first‐order kinetics. Dependence of the rate constant followed the Arrhenius relationship. Apparent activation energies, temperature coefficients, half time and time to reduce to 90% of the initial value of mancozeb were calculated as kinetic parameters. The thermodynamic parameters of mancozeb were also described as Δg^d = ? 2.440 and 7.074 kJ mol^?1; Δh^d = ? 32.555 and ? 42.767 kJ mol^?1; Δs^d = ? 0.090 and ? 0.150 kJ mol^?1 K^?1; K_e = 0.414 and 9.797 L g^?1 for 333 and 373 K respectively. CONCLUSION: Current findings may shed light on the reduction of mancozeb residue and its toxic degradation product during thermal processing of tomatoes and may also be valuable in awareness and prevention of potential risks from dietary exposure. Copyright © 2011 Society of Chemical Industry     

Determination of physicochemical properties of multifloral honeys stored in different containers

In comparison with the initial values, acidity and 5‐(hydroxy‐methyl)‐2‐furaldehyde (HMF) values of all honey samples increased during storage. The total phenol contents of honey were decreased from 286.2 to 108.6 mg GAE/kg during 9 months of storage in white colored container. In addition, total phenol contents of honey sample stored in tin container ranged from 294.7 to 258.6 mg GAE/kg (p < .05). While radical scavenging activity values of honey samples stored in amber colored container during storage are measured as 78.6 g/L, IC₅₀, 77.9 g/L, IC50, and 76.1 g/L, IC₅₀, these activity values were determined as 84.9 g/L, IC₅₀, 80.7 g/L, IC_50, and 75.2 g/L, IC₅₀ in tin container (p < .05), respectively. While acidity values of honey samples stored in white bottle range from 23.6 (3th month) to 25.7% (9th month), it varied from 20.6 (3th month) to 21.6% (9th month) in honey sample stored in amber colored container during storage.

Practical applications

Different honeys are produced in different parts of Turkey. The known honeys are pine, citrus, and chestnut honey. Various flower honeys are produced in these and other regions. HMF formation is considered as a bed result of storage and heating.     

Inhibitory effect of sour orange (Citrus aurantium) juice on Salmonella Typhimurium and Listeria monocytogenes

The sour orange (Citrus aurantium) juice is commonly used as flavoring and acidifying agent for vegetable salads and appetizers in Turkey. It was aimed to determine the survival and growth pattern of Salmonella Typhimurium and Listeria monocytogenes in sour orange juice. Different concentrations of neutralized and un-neutralized juice samples were inoculated with each of the test microorganisms (∼6 log CFU/mL) separately and then incubated at 4 °C and 37 °C for seven days. It was detected both of the test microorganisms could survive and even grow in neutralized juice samples at 37 °C for two days. However, none of them could survive at the end of seventh day of incubation at 37 °C. Low incubation temperature (+4 °C) increased the survival of the tested microorganisms. Also, it was detected that L. monocytogenes were less resistant to the variable conditions than S. Typhimurium. It was concluded that the antimicrobial effect of sour orange juice mainly depends on the low pH value of the product. However, incubation time and temperature are also effective on the survival of the tested pathogens.     

Viability of Escherichia coli O157:H7 during manufacturing and storage of a fermented,semidry soudjouk-style sausage

Soudjouk-style batter was inoculated with a five-strain mixture of Escherichia coli O157:H7 at about 7.6 log10 CFU/g in each of two trials. The sticks were fermented and dried at 22 degrees C and 50% relative humidity (RH) for 3 days and then at 9 degrees C and 40% RH for 18 h. After being flattened to about 1.25 cm, the sticks were conditioned at 38 degrees C and 70% RH or at 22 degrees C and 50% RH for about 3 days. After the latter conditioning treatment, sticks either were cooked to an internal temperature of 63 degrees C or received no heat treatment. Final mean pH values after conditioning at 22 degrees C and 50% RH for soudjouk manufactured with a starter culture and dextrose (1.0%) and for soudjouk manufactured without a starter culture were about 4.9 and 6.0, respectively. For soudjouk produced with a starter culture, pathogen numbers were reduced by 4.53 and 0.88 log10 CFU/g after conditioning at 38 degrees C and 70% RH and at 22 degrees C and 50% RH, respectively. For soudjouk produced via natural fermentation, pathogen numbers were reduced by 1.39 and 0.09 log10 CFU/g after conditioning at 38 degrees C and 70% RH and at 22 degrees C and 50% RH, respectively. Cooking reduced pathogen numbers to below the levels detectable by direct plating (<1.0 log10 CFU/g) and by enrichment for soudjouk produced with a starter culture and also reduced pathogen numbers by 6.28 log10 CFU/g for soudjouk produced via natural fermentation. However, cooking also resulted in an unacceptable product. In general, the reduction in pathogen numbers achieved by storage at ambient temperature (25 degrees C) was greater than that achieved by storage at cooler temperatures (4 and 15 degrees C), particularly for soudjouk prepared with a starter culture (for which a final pH value of 4.8 and a 6.4-log10 reduction were obtained after 21 days at 25 degrees C) rather than for that prepared without a starter culture (for which a final pH value of 6.1 and a 2.6-log10 reduction were obtained after 21 days at 25 degrees C). These results indicate that naturally fermented old-country-type sausage may allow the survival of E. coli O157:H7 in the absence of controlled fermentation, postfermentation cooking, and/or an ambient-storage processing step.     

Antioxidant abietane diterpenoids from Salvia barrelieri

The root extract of endemic Algerian Salvia species Salvia barrelieri Ettling and its diterpenoids were investigated for potential antioxidant activity. From its acetone extract, a new natural abietane diterpenoid 7-oxoroyleanone-12-methyl ether (1) and six known diterpenoids 7α-acetoxyroyleanone-12-methyl ether (2), royleanone (3), horminone (4), 7-acetylhorminone (5), cryptojaponol (6) and inuroyleanol (7) were isolated, and their structures were elucidated by spectroscopic means. Among the diterpenoids, the new diterpenoid 7-oxoroyleanone-12-methyl ether (1) showed highest superoxide anion scavenging activity while inuroyleanol (7) showed both the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity and inhibition of lipid peroxidation in β-carotene–linoleic acid system. These findings indicate that S. barrelieri extract as well as isolated abietane diterpenes, particularly inuroyleanol are promising antioxidants which can be used as food additives.