Antagonistic effect on Listeria monocytogenes and L. innocua of a bacteriocin-like metabolite produced by lactic acid bacteria isolated from sucuk.

Two Lactobacilli and four Pediococci strains producing bacteriocin-like metabolities isolated from sucuk were tested with agar spot tests and well diffusion assays for their inhibitory activity against 16 Listeria strains, also isolated from sucuk. The production of organic acids and hydrogen peroxide limited, L. sake Lb 706 (used as a bacteriocin producer strain) and the isolated lactic acid bacteria (LAB) showed inhibitory activity against all of the Listeria strains, while L. sake Lb 706-A (used as a bacteriocin non-producer mutant) had the same effects against only two Listeria monocytogenes strains (51, 52) in agar spot tests. In the well diffusion assays, while L sake Lb 706 and four Pediococci isolates (413, 416, 419, 446) exhibited inhibitory activity against all of the Listeria strains tested, L. sake Lb 706-A and two of the Lactobacilli isolates (77, 116) showed no effect on the Listeria strains tested.

Production of bacteriocin-like metabolites by lactic acid cultures isolated from sucuk samples.

A total of 51 sucuk samples, obtained from different regions of Turkey, were examined for lactic acid bacteria (LAB) strains producing putative bacteriocin-like metabolites. For detection of antagonistic activity, agar spot and well diffusion assay tests were used. Lactobacillus sake Lb790, Listeria monocytogenes Li6, Staphylococcus aureus St44 and Escherichia coli NRRL B-3704 were used as indicator organisms. Strains having antimicrobial activity were also tested against Clostridium perfringens 4TTK, Clostridium botulinum type A. 7948, Bacillus cereus NRRL B-3711, Micrococcus luteus NRRL B-4376 and Yersinia enterocolitica type 103. 57 of 424 isolates from sucuk samples were putative producers of bacteriocin-like metabolistes and were identified as the following: 19 Lactobacillus plantarum, 4 L. curvatus, 4 Pediococcus pentosaceus, 3 P. acidilactici, 2 L. pentosus, 2 L. sake, 1 L. delbrueckii, 1 L. rhamnosus and 21 unidentified Lactobacillus spp. P. pentosaceus 416, P. acidilactici 413, 419 and 446, L. curvatus 348, L. plantarum 452 and 495, and Lactobacillus spp. 411 strains have the best potential for use as sucuk starter cultures.

Effects of Different Fruits and Storage Periods on Microbiological Qualities of Fruit-Flavored Yogurt Produced in Turkey.

Comparative microbiological analyses of fruit-flavored yogurt, plain yogurt, and plain yogurt with 8% sugar were conducted in this research. The fruit-flavored yogurts were produced from evaporated cow's milk (19.75% dry matter) containing 16% jam prepared with an equal weight of sugar and fruit (sour cherry, orange, strawberry, or banana). The total plate count, lactic acid and coliform bacteria, and yeast and mold counts were determined in yogurt samples stored for 1, 3, 5, 7, 9, and 13 days. In conclusion, it is suggested that these types of yogurt should not be stored longer than 7 days, because when a carryover culture is used for yogurt production, most likely yeast contamination will occur. Otherwise, pure starter culture should be utilized in yogurt production.

Basic chemical characteristics of fresh, non-packed and vacuum-packed sheep-tail and tail-fat stored frozen for different periods.

Fatty tails were obtained after the slaughter of Morkaraman sheep, which are a common breed of fatty-tailed sheep in Turkey. Fat obtained from sheep tails, (called tail-fat) is used either in fresh condition or after frozen storage. This fat is commonly used as a food source in many countries in which fat-tail sheep breeds are raised; but there has been no detailed research on fatty tails or the tail-fat. In this work some quality criteria such as water, fat and nitrogen content, 2-thiobarbituric acid and peroxide numbers, free fatty acids, melting point, iodine and saponification numbers were studied in sheep tails and sheep tail-fat, both in the fresh condition and after storage at -18 ± 1°C for up to 60 days. The effect of vacuum packaging versus storage in netting bags (no-protection, non-packed), was also determined. The fat content of the tails was around 94%. Thus, the tail is a concentrated fat source. Some quality criteria of the tail and the tail-fat were determined and are given in the text. Overall results indicated that both the tail and the tail-fat can be effectively used in various types of food and food processing, especially after performing some technological and refining processing. If the fatty tail has to be stored, it should be vacuum packed and stored frozen. At -18°C, vacuum-packed tail samples could be stored around 45 days, but in the netting bags, this storage period should not exceed 30 days.

Effects of shooting period, times within shooting periods and processing systems on the extract, caffeine and crude fiber contents of black tea.

The extract, caffeine and crude fibre contents of black tea, from different shooting periods, different times within each shooting period and processed by five different commercial rolling methods, were examined. The extract and crude fibre contents of black tea were significantly (P < 0.01) affected by all these factors and their interactions. The caffeine content of black tea was affected by the shooting period and times within the shooting period. It was determined that processing methods did not have a significant (P < 0.05) effect on the caffeine content. The amount of extract and caffeine decreased from the first shooting period to the third, and also from the beginning of each shooting period to the end. However, the crude fibre content of the black tea increased, especially from the beginning of each shooting period to the end of each shooting period.

K and Ca content of fresh green tea, black tea, and tea residue determined by X-ray fluorescence analysis.

X-Ray fluorescence (XRF) can be successfully used for the qualitative and quantitative elemental analysis of various agricultural products. Its simplicity, high throughput and the possibility of automation make it useful for screening large numbers of samples. The K and Ca content of 138 samples of fresh green tea, black tea and black tea residues were determined by applying the XRF system. Such a method of mineral analysis of food products is not very common. Tea from different tea-growing areas of Turkey, green tea of different shooting periods, black tea processed at different tea plants and tea residues from these black tea were analysed. The K content of green tea, processed black tea and tea residues after brewing were found to have ranges of 19,049-26,254 mg/kg, 21,904-26,883 mg/kg and 9,468-13,778 mg/kg, respectively. In the same samples the Ca content was determined as 3,580-4,799 mg/kg, 3,370-4,823 mg/kg, and 3,743-5,733 mg/kg, respectively. These findings were compared with the results of atomic emission techniques and it was concluded that the XRF system could be effectively used for quantitative analysis of the K and Ca content of tea samples.

Model system evaluations of the effects of different levels of K(2)HPO(4) NaCl and oil temperature on emulsion stability and viscosity of fresh and frozen turkish style meat emulsions.

The effects of different levels of K(2)HPO(4), NaCl, and the effects of oil temperature used in the evaluation of emulsion stability and viscosity of fresh and frozen beef (fat level adjusted with tail fat from sheep) was studied by utilizing a model system. Emulsion stability (ES) and emulsion viscosity (EV) of frozen meat tissue were both decreased, by 3·6% and 10·5% respectively, when compared to fresh meat. ES was decreased by 4·0% and 3·7% at 5°C and 11°C oil temperature respectively when compared to 21°C. While EV decreased 12·2% at 11°C compared to 21°C, it did not show any statistically significant (P < 0·01) change at 5°C oil temperature. ES and EV were elevated with the addition of phosphate and increasing phosphate levels. These increases for ES were 3·9% and 3·7% with 0·50% and 0·75% phosphate levels respectively, when compared to the 0·00% phosphate control group. Also, the increases for EV were 22·3% and 27·0% with 0·50% and 0·75% phosphate levels respectively, compared to the 0·00% phosphate control group. The alteration of the ES was not statistically P < 0·01) significant for the 0·50% phosphate level when compared to the 0·75% phosphate level. The ES decreased 1·1% for a 3·0% salt level when compared to a 2·5% salt level, and there was statistically (P < 0·05) no effect on the EV.

Physical, chemical and organoleptic characteristics of Turkish style frankfurters made with an emulsion containing Turkish soy flour.

The possibility of using Turkish Defatted Soy Flour (DSF) to replace part of the meat in Turkish style frankfurters was studied and the technological, physical, chemical, nutritional, sensory and quality characteristics of these sausages produced under Turkish conditions were determined. No significant difference in physical and sensory properties between the control group (all meat) and treatment groups (5, 10 and 20% soy flour) was found. DSF up to the level used significantly (P > 0·01) increased moisture and protein and decreased fat levels of the sausages. The amino acid and PER results also indicated that replacing meat with DSF in sausages did not significantly alter the nutritional value of the sausages.

Saprophytic and Pathogenic Bacteria Levels in Turkish Soud-jouks Manufactured in Erzurum, Turkey 1.

In Turkey, spicy, typically dry, fermented sausage (soudjouk) is one of the most popular processed meat products. In this study, 42 soudjouk samples were collected from the eight manufacturers in Erzurum, Turkey. These samples were evaluated for aerobic plate count (APC) at 37 and 25°C, psychrotrophic, coliform, Escherichia coli , and coagulase-positive Staphylococcus aureus counts and presence of Salmonella and Shigella spp. Generally, all the samples had very high counts of most of the bacteria enumerated. In two samples of the 42, Shigella spp. was found and one of them was Shigella boydii . None of the samples yielded Salmonella spp.