Antioxidant and angiotensin-I converting enzyme inhibitory activity in the water-soluble protein extract from Petrovac Sausage (Petrovská Kolbása)

Petrovac Sausage (Petrovská Kolbása) is a traditional dry fermented sausage from Bački Petrovac (province Vojvodina, Serbia). In this study, the in vitro antioxidant and angiotensin-I converting enzyme (ACE) inhibitory activities in the water-soluble (pH 7.4) protein extracts were evaluated throughout the sausage ripening. In the protein extract from the sausage mixture (day 0) degree of hydrolysis (DH) of 6.07 ± 0.84% was determined, which reached 17.71 ± 0.76% after 90 days. The protein extract at day 0 showed free radical (2.2-diphenyl-1-picrylhydrazyl, DPPH) scavenging assay (RSA) and reducing power (RP) of 27.61 ± 0.73% and 0.493 ± 0.016, respectively. In fermented sausage at day 90, RSA and RP increased up to 50.08 ± 1.25% and 0.972 ± 0.065%, respectively. The examined protein extracts exhibited ACE inhibitory activity, which also enhanced; from 27.11 ± 2.163% (day 0) to 73.74 ± 3.299% (day 90). These results suggested that in Petrovská Kolbása, the final products of meat proteins hydrolysis during sausage ripening might be hydrolysates with antioxidant and ACE inhibitory properties.     

Antibacterial activity and chemical constitutions of Ziziphora clinopodioides

The essential oil and methanol extract obtained from aerial parts of Ziziphora clinopodioides Lam. harvested in the Eastern part of Turkey were evaluated for their chemical composition and antibacterial activity against 52 Gram-positive and Gram-negative bacteria. The GC–MS analyses allowed 18 compounds to be determined; the main constituents of the essential oils were (+)-pulegone (31.86%), 1,8-cineole (12.21%), limonene (10.48%), menthol (9.13%), β–pinene (6.88%), menthone (6.73%), piperitenone (5.30%) and piperitone (4.18%) The essential oil and methanol extract had a broad-spectrum antimicrobial activity against pathogens in broth microdilution bioassays. Maximum activity of essential oil (>22 mm) and methanol extract (>11 mm) was observed against Acidovorax facilis, Bacillus flexus, Bacillus spp, Bacillus sphaericus, Brevibacillus brevis, Corynebacterium ammoniagenes, Enterobacter sakazakii, Erwinia carotovora carotovora, Moraxella catarrhalis and Xanthomonas arboricola.     

Essential oils composition,antioxidant and antimicrobial activity of the leaves and flowers of Chaerophyllum macropodum Boiss

This study reports the essential oils chemical composition and in vitro antioxidant and antimicrobial potentials of the leaves and flowers of Chaerophyllum macropodum. GC and GC/MS analysis of the plant essential oils led to the identification of 49 components making 98.3–99.4% of its oils. The main constituents of the essential oils were trans-β-farnesene, trans-β-ocimene, β-pinene, limonene, spathulenol and myrcene constituting 49.6–73.1% of the oils. The extracts from the leaves and flowers showed moderate antioxidant activities in 1,1-diphenyl-2-picrylhydrazyl (DPPH) test (IC₅₀ values = 196.8 and 167.1 μg/ml respectively) and β-carotene/linoleic acid assay (inhibitions percentages = 69.9% and 62.7% respectively), but the essential oils were almost inactive in these tests. On the other hand, only the essential oils of the plant showed considerable antimicrobial activity against most of the tested microorganisms.     

In vitro control of growth and ochratoxin A production by butylated hydroxyanisole in Aspergillus section Nigri species

This study was carried out to determine the efficacy of phenolic antioxidant butylated hydroxyanisole (BHA) under different interacting water activity (a_W) and temperature regimes on the lag phase and growth rate by Aspergillus section Nigri strains. In this experiment four A. section Nigri strains were used. Peanut meal extract agar (PMEA) was prepared at 2%. The a_W of the medium was adjusted to 0.995, 0.980 and 0.930, BHA at 1, 5, 10 and 20 mmol l^?1 was added to the basic medium. The plates were inoculated and incubated for 30 days at 18 and 25 °C. Radial growth rates (mm d^?1) and lag phase (h) were calculated. In control treatments, the growth rate decreased as water activity reduced in all strains assayed. At all a_W levels tested, BHA at 20 mmol l^?1 completely inhibited growth. In general, at 10 mmol l^?1 and 0.995 and 0.980a_W level, a significant reduction respect to control was observed. This antioxidant completely inhibited OTA production, at concentrations of 20 mmol l^?1, regardless of a_W used by all the strains evaluated.     

Paralytic toxins in four species of coral reef crabs from Kenting National Park in southern Taiwan

Paralytic toxicity was detected by tetrodotoxin (TTX) bioassay in 41 specimens of four species of coral reef crabs collected from Kenting National Park, southern Taiwan from January 2003 to March 2004. The frequency of toxicity in Zosimus aeneus, Xanthias lividus, Actaeodes tomentosus (Xanthidae family) and Camposcia retusa (Majidae family) specimens was 93.3%, 100%, 46.7% and 66.7%, respectively. The average toxicity of crab specimens was 483 ± 225 (mean ± SD) mouse units (MU) for Z. aeneus, 51 ± 32 MU for X. lividus, 6 ± 5 MU for A. tomentosus, and 18 ± 11 MU for C. retusa. Each toxin of four species of crabs was extracted with acidic methanol, cleansed using a C18 solid-phase extraction column, filtered through a microcentrifuge filter and analyzed by HPLC, LC-MS and GC-MS. The toxins of Z. aeneus and X. lividus contained TTX (90%) and a small amount of gonyautoxins (10%), whereas those of A. tomentosus and C. retusa all mainly contained TTX, but no paralytic shellfish poison. Except for Z. aeneus and X. lividus, two species A. tomentosus and C. retusa were first recorded as toxic in Taiwan.     

Antibacterial effect of black seed oil on Listeria monocytogenes

Listeria monocytogenes is a major foodborne pathogen in the United States. Effective methods for reducing L. monocytogenes in foods would reduce the likelihood of foodborne outbreaks of listeriosis, and decrease economic losses to the food industry. Nigella sativa is a herbaceous plant, whose seeds (black seed) have been used as a spice and condiment in foods in the Middle East. The objective of this study was to determine the antibacterial effect of black seed oil on twenty strains of L. monocytogenes by disc diffusion method. A population of 7.0 log CFU of each strain of L. monocytogenes was inoculated on duplicate plates containing antibiotic medium one agar. The plates were allowed to dry at room temperature for 15 min. Three discs (6 mm diameter), each impregnated with 10 μl of black seed oil, vegetable oil (oil control), or gentamicin (positive control) were placed on each inoculated plate. The plates were incubated at 37 °C for 24 h, and were observed for zones of L. monocytogenes growth inhibition. Black seed oil exhibited a strong antibacterial activity against all the strains of L. monocytogenes, yielding a significantly (P<0.01) larger inhibition zone than that of gentamicin. The mean zones of inhibition produced by black seed oil and gentamicin were 31.50 ± 1.0 and 14.80 ± 0.50, respectively. The vegetable oil had no inhibitory effect on L. monocytogenes. Results indicate that black seed oil could potentially be used to inhibit L. monocytogenes, but appropriate applications in foods need to be validated.     

Investigations on the essential oil of Lippia rugosa from Cameroon for its potential use as antifungal agent against Aspergillus flavus Link ex. Fries

Lippia rugosa essential oil was tested for its effectiveness against Aspergillus flavus on artificial growth media. The chemical composition of the oil was determined by gas chromatography–mass spectrometry (GC–MS). Geraniol (51.5%), nerol (18.6%) and geranial (10.4%) were the main components of Lippia oil. After 8 days of incubation on essential oil supplemented medium, mycelium growth of A. flavus was totally inhibited by 1000 mg l^?1 of L. rugosa essential oil. The effect of essential oil on aflatoxin B₁ synthesis was evaluated in SMKY broth. The medium supplemented with different essential oil concentrations, was inoculated with A. flavus mycelium and incubated at 25 °C. After 2, 4, 6 and 8 days, aflatoxin B₁ (AFB₁) was quantified in the supernatant using Enzyme Linked Immuno-Sorbent Assay (ELISA). Results showed that aflatoxin B₁ synthesis was inhibited by 1000 mg l^?1 of L. rugosa essential oil after 8 days of incubation. The effect of the EO on the H⁺-ATPase pumping membrane was also evaluated in the presence of several concentrations of oil (200–2000 mg l^?1) by monitoring glucose-induced acidification of the external medium. L. rugosa essential oil at the concentration of 2000 mg l^?1 completely inhibited the activity of this enzyme. These data suggest that the essential oil of L. rugosa is a fungicidal for A. flavus and its possible cellular target include the H⁺-ATPase.Results obtained in the present study indicate the possibility of exploiting Lippia rugosa essential oil in the fight against strains of A. flavus responsible for biodeterioration of stored foods products.     

Pre-processed bovine milk quality in Trinidad: Prevalence and characteristics of bacterial pathogens and occurrence of antimicrobial residues in milk from collection centres

The study was conducted to assess the impact of the changes in the milk collection system in Trinidad (from twice daily collection to once, introduction of chilling facilities to the collection centres and transportation of milk to the processing plant in insulated truck instead of in metal churns at ambient temperature) on the microbial load and antimicrobial residue quality of the milk as well as the temperature and pH of milk, using standard methods. The presence of antimicrobial residues was detected using the Delvo test kit. Of a total of 266 milk samples from churns, the mean ± sd temperature and log₁₀ ± sd TAPC per ml was 20.36 ± 7.91 °C and 6.3 ± 1.09 respectively. For 20 milk samples from the chillers, the mean temperature and log₁₀ ± sd TAPC per ml was 15.10 ± 2.73 °C and 7.04 ± 0.33 respectively compared with corresponding values for 36 samples collected from the truck, 11.64 ± 4.22 °C and 7.11 ± 0.62 respectively (P < 0.05; X²). The mean TAPC, staphylococcal and E. coli counts per ml of milk from churns were significantly (P < 0.05; X²) higher for milk at low temperature (0–20 °C) compared with milk at high temperature (>30 °C). Eight (4.2%) of 192 milk samples tested contained antimicrobial residues. Of 168 S. aureus isolates tested, 24 (14.3%) were enterotoxigenic while 53 (45.3%) of 117 isolates tested exhibited resistance to various antimicrobial agents while of 386 isolates of E. coli tested, 3 (0.8%) were O157 strain and 129 (64.5%) of 200 isolates exhibited resistance to antimicrobial agents. It was concluded that despite the changes, the microbial load of milk was still high suggesting poor sanitary practices at the farm level. The detection of antimicrobial residues agents coupled with toxigenic S. aureus and E. coli isolates could pose health hazards to consumers.     

Effects of Zataria multiflora Boiss. essential oil and nisin on Bacillus cereus ATCC 11778

The effects of different concentrations of Zataria multiflora Boiss. essential oil (EO, 0.0%, 0.005%, 0.015%, 0.03% and 0.045%) and nisin (N, 0.0, 0.25, 0.5, 1.5 and 2.5 μg ml⁻¹), pH values (7.4, 6.5 and 6.0), temperatures (Ts, 10, 20 and 30 °C) and storage times (Ds, up to 43 days) on log₁₀ probability percentage of growth initiation (log P%) of one vegetative cell of Bacillus cereus in brain heart infusion broth were evaluated in a factorial design study. The log P% of the organism was significantly affected (P < 0.01) by the values of EO, N, pH, T and D.The combinations of T ⩾ 20 °C, EO ⩽ 0.03% and pH values (7.4, 6.5 and 6.0) could not obviously affect the growth of the organism in this study. Whereas, the strong inhibitory action was observed by increasing EO concentration to 0.045 at T ⩾ 20 °C and selected pH values (7.4, 6.5 and 6.0) and by decreasing temperature to 10 °C at EO ⩾ 0.015% and pH values used in this study. The inhibitory effect of N also was enhanced by decreasing storage temperature to 10 °C at the selected pH values (7.4, 6.5 and 6.0) in this study.The growth of the organisms was strongly affected by increasing EO concentration to 0.03% in combination with N concentrations used at the selected temperatures in this study. The growth of the organism was completely inhibited at combinations EO ⩾ 0.015%, N ⩾ 1.5 μg ml⁻¹, T ⩽ 30 °C and pH ⩽ 7.4 during 43 days of storage in this study. This synergistic effect of EO and N was enhanced in lower pH values (6.5 and 6.0) in the present study. The growth of organism was completely inhibited at combinations of EO ⩾ 0.005 and N ⩾ 1.5 μg ml⁻¹ at pH = 6.0, and EO ⩾ 0.03 and N ⩾ 0.5 μg ml⁻¹ at pH ⩽ 6.5 during the study at the selected Ts (30, 20 and 10 °C).     

Seasonal variation in the chemical composition and microbiological condition of Mediterranean horse mackerel (Trachurus mediterraneus) muscle from the North Aegean Sea (Greece)

The aim of this work was to determine the chemical composition and microbiological quality of Mediterranean horse mackerel (Trachurus mediterraneus) muscle during the year and the consequent advantages or disadvantages in processing the raw material. A total of 180 samples were examined (15 samples per month) during two years (November 2001–November 2003). Fish were caught in the coastal waters of Chalkidiki peninsula (Northern Greece). Proximate composition of the muscle during the year resulted in: water 76.8 ± 1.39%, proteins 20.3 ± 0.68%, fat 1.3 ± 1.08% and ash 1.5 ± 0.08%. In March, April and May an increase in fat content of the muscle (2.5%, 2.8% and 2.1%, respectively) and a decrease in water content of the muscle (below 75.9%) were observed. On the contrary, fat content showed a decrease in September and October (0.4% and 0.6%, respectively), while water content of the muscle increased during these months (78.2% and 77.6%, respectively). The protein content of the muscle remained at high values, while the ash content was almost constant during the year. The mean value of muscle pH was 6.38 ± 0.16; extreme values (<6 or >7) of muscle pH were not observed. Total Viable Bacteria, Shewanella putrefaciens and Pseudomonas spp. were used as microbial indices to evaluate the microbiological quality of the muscle. Mean counts of Total Viable Bacteria, S. putrefaciens and Pseudomonas spp. during the year were: 4.01 ± 0.38 log₁₀ cfu/g, 2.37 ± 0.43 log₁₀ cfu/g and 3.34 ± 0.27 log₁₀ cfu/g, respectively. The variations of the values within seasons are minimal and significant homogeneity in the chemical composition and microbiological quality of Mediterranean horse mackerel muscle is observed. This is an important advantage in processing of the raw material.     

Microbial profile of buffalo sausage during processing and storage

A study was made on the microbial levels of buffalo sausage during preparation and storage at 4 ± 1 °C. Microbial counts in raw minced meat were, total plate count (TPC) (log cfu/g) 5.41 ± 0.25; coliforms (MPN/g) 23.2; Staphylococcus aureus (log cfu/g) 1.57 ± 0.11; yeasts and molds (log cfu/g) 2.29 ± 0.07 and lactic acid bacteria (LAB) (log cfu/g) 0.60 ± 0.20. Sausage emulsion showed similar trend in microbial counts with minimal microbial contamination during the preparation of emulsion. Cooked buffalo sausage gave the following microbial counts: TPC (log cfu/g) 3.75 ± 0.31; coliforms (MPN/g) 0.2; LAB (log cfu/g) 0.07 ± 0.01; yeast and molds (log cfu/g) 0.72 ± 0.07. S. aureus, Clostridium perfringens and Bacillus cereus were not detected in cooked sausages. These results indicate that steam cooking for 45 min followed in the study was effective in reducing the microbial counts substantially. The investigation revealed that shelf life of cooked buffalo sausage was 31 days in either vacuum or CO₂ at 4 ± 1 °C. The results indicated that spoilage of vacuum packed cooked buffalo sausage was likely due to LAB while microflora other than LAB may be responsible for spoilage of CO₂ packed cooked buffalo sausage. The study suggests that measures such as low initial microbial counts, hygienic precautions during preparation of sausage, steam cooking for 45 min, vacuum or CO₂ packing and storage at 4 ± 1 °C would control the microbial growth and provide wholesomeness and safety to the buffalo sausage.     

Thermally treated wine retains antibacterial effects to food-born pathogens

Although cooking with wine and consumption of wine as a warm beverage is widespread, antibacterial effects of thermally treated wine have not been studied.We examined in vitro antibacterial activity of wine heated at 75 and 125 °C for 45 min against Salmonella enterica serovar Enteritidis and Escherichia coli. Their effects were compared with intact red wine, dealcoholized wine (DW) and dealcoholized wine reconstituted (RDW) with water to the initial volume. Samples were also analysed for their phenolics content, antioxidant capacity, resveratrol and ethanol content and pH.Total phenolics concentration and related antioxidative activity followed changes in samples volume, regardless of treatment type, while pH of all samples remained stable and ranged from 3.09 to 3.24.The order of the antibacterial activity of wine samples was: intact wine > heated at 75 °C > heated at 125 °C > DW > RDW.Antibacterial activity of the samples could not be related to their content of resveratrol as a single phenolics compound, antioxidative capacity or pH.Thermally treated wine under conditions applicable to food processing in everyday life, may be effective antibacterials in spite of significant heat-induced changes in their physical–chemical composition.     

Essential oils to control Alternaria alternata in vitro and in vivo

The inhibitory effects of five essential oils (thyme, sage, nutmeg, eucaptus and cassia) against Alternaria alternata were tested at different concentrations (100–500 ppm) in vitro. The cassia oil and thyme oil both exhibited antifungal activity against A. alternata. The cassia oil inhibited completely the growth of A. alternata at 300–500 ppm. The thyme oil exhibited a lower degree of inhibition 62.0% at 500 ppm. Spore germination and germ tube elongation of the pathogens in potato dextrose broth was strongly inhibited in the presence of 500 ppm cassia oil. Irreversible inhibition of fungal growth could be caused by exposure to 300 ppm and 400 ppm cassia oil for 6 days and 500 ppm cassia oil for 3 days. Cassia oil at 500 ppm reduced the percentage of decayed tomatoes. The experiments on reducing natural decay development of tomatoes gave similar results. Therefore, essential oils could be an alternative to chemicals for control of postharvest phytopathogenic fungi on fruits or vegetables.     

Efficiency of high pressure treatment on inactivation of pathogenic microorganisms and enzymes in apple,orange, apricot and sour cherry juices

The purpose of this study was to investigate the effect of high hydrostatic pressure with a mild heat treatment on Staphylococcus aureus 485, Escherichia coli O157:H7 933 and Salmonella Enteritidis FDA in apple, orange, apricot and sour cherry juices. The effectiveness of the treatment on polyphenol oxidase activity in apple juice and pectinesterase activity in orange juice were also determined. An inoculum of microorganisms was completely inactivated at 350 MPa and 40 °C in 5 min. The residual polyphenol oxidase activity in apple juice after treatment at 450 MPa and 50 °C for 60 min was obtained as 9 ± 2.2%. The residual pectinesterase activity in orange juice after treatment at 450 MPa and 50 °C for 30 min was determined as approximately 7 ± 1.6%. It compares with 12 ± 0.2% at a treatment of 40 °C and 450 MPa for 60 min. Pressure resistant isoenzymes were thought to be responsible for the final residual activity. The inactivation is irreversible and the enzyme is not reactivated upon storage. High pressure processing constitutes an effective technology to inactivate the enzymes in fruit juices. Pressures higher than 400 MPa can be combined with mild heat (<50 °C) to accelerate enzyme inactivation.     

Chemical constituents,antifungal and antioxidative potential of Foeniculum vulgare volatile oil and its acetone extract

GC and GC–MS analysis of Foeniculum vulgare volatile oil showed the presence of 35 components containing 96.4% of the total amount. The major component was trans-anethole (70.1%). The analysis of its acetone extract showed the presence of nine components accounting for 68.9% of the total amount. Linoleic acid (54.9%), palmitic acid (5.4%) and oleic acid (5.4%) were found as major components in extract. The antifungal and antioxidative potentials were also carried out by different techniques. In inverted petriplate method, the volatile oil showed complete zone inhibition against Aspergillus niger, Aspergillus flavus, Fusarium graminearum and Fusarium moniliforme at 6 μL dose. It was found to be effective for A. niger even at 4 μL dose. Moreover, using food poison technique, the volatile oil and extract both showed good to moderate zone of inhibition. The antioxidant value was evaluated by measuring peroxide and thiobarbituric acid values for linseed oil at fixed time intervals. Both, the volatile oil and extract showed strong antioxidant activity in comparison with butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). In addition, their inhibitory action in linoleic acid system was studied by monitoring peroxide accumulation in emulsion during incubation through ferric thiocyanate method. The results were well correlated with the above results.     

Influence of the hydrophobicity and surface roughness of mangoes and tomatoes on the adhesion of Salmonella enterica serovar Typhimurium and evaluation of cleaning procedures using surfactin

Salmonellosis is associated with the consumption of raw vegetables and fruits such as tomatoes, watermelons, alfalfa sprouts, radishes, carrots, lettuce and parsley. The influence of the fruits' roughness on bacterial adhesion was evaluated as measured using a profilometer. The adhesion of Salmonella enterica serovar Typhimurium to mango and tomato surfaces was also evaluated by measuring of the hydrophobicity of the microorganisms and the fruits surfaces. The bacteria adherent on fruit's surface was quantified by plate count and visualize by scanning electron microscopy. In addition, the efficiency of surfactin in removing S. Typhimurium from the fruits' surfaces was analyzed. The average roughness (R_a) of mango (4.54 ± 1.95 μm) was significantly different (p < 0.05) compared to tomato (2.88 ± 2.15 μm). The adhesion of the microorganisms to the fruits' surfaces, as predicted by a determination of the total energy of adhesion (ΔG), was thermodynamically unfavorable. Despite these data, the numbers of bacteria on both fruits' surfaces were similar (p > 0.05), reaching 5.95 ± 0.36 log CFU cm⁻² and 5.81 ± 0.39 log CFU cm⁻² on mango and tomato, respectively. Therefore, these results suggest that the adhesion observed in this experiment is a multifactorial process. Surfactin removed 94.3% and 92.2% of the S. Typhimurium adhered to the surfaces of the mangoes and tomatoes, respectively. Our research showed that the roughness and hydrophobicity of the fruits' surface did not affect the efficiency of each sanitation treatments on removing of S. Typhimurium. It was observed that the chlorine was more efficient treatment (p < 0.05) for tomato surface. For surface of mangoes, chorine and surfactin were better than water treatment for bacteria control.     

Validation of the procedure for the determination of aflatoxin B1 in animal liver using immunoaffinity columns and liquid chromatography with postcolumn derivatisation and fluorescence detection

The validation of the procedure for the determination of aflatoxin B₁ in animal liver (pig, chicken, turkey, beef, calf) was performed. The limit of detection (LOD) and limit of quantification (LOQ) were 2 ng/kg and 7.8 ng/kg, respectively. The repeatability of measurements, represented by the standard deviation (RSD_r) was 7.5%, 7.1%, and 4.8% at the contamination levels of 0.025 μg/kg, 0.050 μg/kg, and 0.075 μg/kg, respectively. The relative standard deviation for the within-laboratory reproducibility (RSD_R) was 18% at the level of 0.025 μg/kg and 22% at the levels of 0.050 μg/kg and 0.075 μg/kg. The measurement uncertainties at the same contamination levels were ±0.007 μg/kg, ±0.016 μg/kg, and ±0.023 μg/kg, respectively. The mean recovery was 72.8%, the decision limit (CCα) 0.063 μg/kg and the detection capability (CCβ) 0.080 μg/kg. The results indicate that the procedure is suitable for the determination of aflatoxin B₁ in animal liver and can be implemented for the routine analysis.     

A comparison of microbial contamination on sheep/goat carcasses in a modern Indian abattoir and traditional meat shops

The microbial load on sheep/goat carcasses was investigated in Deonar abattoir and traditional meat shops in Mumbai. A total of 96 swab samples from carcass sites were collected and analysed from the abattoir, while 144 swab samples from carcass sites were analysed from three meat shops. These samples were processed for total viable count (TVC) and differential counts. The average TVC after flaying, evisceration and washing in the abattoir was 5.51 ± 0.36, 6.06 ± 0.53 and 5.13 ± 0.58 CFU/cm², respectively. Pooled average TVC in the shops after flaying, evisceration and washing was 5.83 ± 0.42, 6.48 ± 0.27 and 6.17 ± 0.41 log CFU/cm², respectively. Statistical analysis revealed a highly significant difference (P < 0.01) among TVC counts after washing between abattoir and the shops. The highest prevalence of Micrococcus spp. and S. epidermidis was noticed during various operations in both the abattoir and the shops. Although Salmonella spp. could not be isolated from any of the carcass sites in the abattoir, in the shops it showed 16.4% prevalence at all the sites irrespective of operations. Overall study revealed that level of contamination in the traditional meat shops was significantly higher compared to the abattoir. However, the microbial contamination in the abattoir is also high if we compare these results to the reports from developed countries and do not conform to EU specifications. The findings of this study reflect the hygiene status of meat production in the developing world.     

Comparison of the effects of sesame and Thymbra spicata oil during the manufacturing of Turkish dry-fermented sausage

Effects of sesame, Thymbra spicata oil and BHT (butylated hydroxy toluene) on the quality and safety (pH, biogenic amine, TBARS values, colour and sensory attributes) of Turkish dry-fermented sausage were investigated during the ripening periods. A sharp decrease (P < 0.05) in pH values were observed from 5.84 to about 4.40 during the first 2 days of ripening. The TBARS value and putrescine concentration in recipes were found in the following order: control (S1) > BHT (S2) > sesame oil (S4) > Thymbra spicata oil (S3). Histamine and tyramine concentrations were highest (P < 0.05) in the control recipe, while lowest (P < 0.05) in Thymbra spicata and sesame oil added recipes. The most acceptable recipes were found to be the sesame oil added recipes with respect to their highest overall sensory quality scores. The order of acceptability was found to be S4 = S3 = S2 > S1. The pH, L, b, and YI-values were not significantly changed (P > 0.05) by the addition of Thymbra spicata oil, sesame oil, and BHT. These results indicated that the most effective antioxidant was found to be Thymbra spicata oil. This study pointed out that natural antioxidants could be easily utilized in sausages to enhance quality and get safe products.     

The in vitro antimicrobial and antioxidant activities of the essential oils and methanol extracts of endemic Thymus spathulifolius

The present study was conducted to evaluate the in vitro antimicrobial and antioxidant properties of essential oil and methanol extracts from a unique and endemic plant, Thymus spathulifolius (Hausskn. and Velen.). The antimicrobial test results showed that the essential oil of T. spathulifolius strongly inhibited the growth of test microorganisms studied, except for 4 fungi species while polar and non-polar subfractions of the methanol extract had moderate antibacterial, but not antifungal and anticandidal activity. The antioxidative potential of the samples was evaluated using two separate methods, inhibition of free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) and β-carotene–linoleic acid systems. The polar subfraction of the methanol extract was able to reduce the stable free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) with an IC₅₀ of 16.15 ± 0.5 μg/ml, which was lower than that of synthetic antioxidant, BHT, (19.8 ± 0.5 μg/ml). Inhibition values of linoleic acid oxidation were calculated as 92% and 89% for the oil and the polar subfraction, respectively. Gallic acid equivalent total phenolic constituent of the polar subfraction was 141.00 ± 0.90 μg/mg (14.1%, w/w). The chemical composition of a hydrodistilled essential oil of T. spathulifolius was analyzed by a GC and GC/MS system. A total of 28 constituents representing 99.2% of the oil were identified; thymol (36.5%), carvacrol (29.8%), p-cymene (10.0%) and γ-terpinene (6.3%) were the main components comprising 82.6% of the oil. Results presented here may suggest that the essential oil and extracts of T. spathulifolius possess antimicrobial and antioxidant properties, and therefore, they can be used as a natural preservative ingredient in food and/or pharmaceutical industry.