Assessment of technological attributes of autochthonous starter cultures in Turkish dry fermented sausage (sucuk)

The study aims to evaluate the technological properties of autochthonous strains (Lactobacillus sakei S15, Lactobacillus plantarum S24, L. plantarum S91, Pediococcus pentosaceus S128b and Staphylococcus carnosus G109) in Turkish dry fermented sausage (sucuk). After 24 h of fermentaPtion, all lactic acid bacteria strains reduced the pH to below 5.0, while the pH in the control group was above 5.3. The number of lactic acid bacteria strains reached 10⁸–10⁹ cfu g⁻¹ during fermentation. Staphylococcus carnosus G109 remained at the inoculation level of 10⁶ cfu g⁻¹ during ripening. Lactobacillus sakei S15 as mono-culture showed higher TBARS values compared to other strains. The control group had the lowest L* value and autochthonous strains caused no significant difference for a* value. According to principal component analysis results, most volatile compounds were positively correlated with the group containing only L. sakei S15.     

Biogenic amine formation in Turkish dry fermented sausage (sucuk) as affected by nisin and nitrite

BACKGROUND: The effects of nitrite (0, 100, and 200 mg kg^?1) and nisin (0, 250, and 500 mg kg^?1) on biogenic amine formation in sucuk were investigated by utilising a central composite design of response surface methodology. RESULTS: The addition of nitrite led to decreased levels of tryptamine, 2‐phenylethylamine, putrescine, cadaverine, tyramine, and histamine, whereas nisin decreased the tryptamine level and counts of lactic acid bacteria. However, nisin increased putrescine, cadaverine, and spermidine levels. Their interactive effect was also found to be significant (P < 0.05) for putrescine values. CONCLUSION: The additional nitrite levels can be decreased by the addition of nisin, which will hinder biogenic amine formation. Copyright © 2010 Society of Chemical Industry     

Quality characteristics of doner kebab made from sucuk dough which is a dry fermented Turkish sausage

The objective of this study was to determine certain quality characteristics of the raw and cooked doner kebabs made from beef and sucuk dough which is a traditional fermented sausage. The doners were divided into two groups; traditional beef doners and sucuk dough groups, and all the samples were frozen and stored at (−30 ±1 °C) for 60 days to monitor their quality characteristics. All of the raw and cooked doner samples were subjected to chemical and microbiological analysis while only the cooked doners were evaluated organoleptically at 0th, 30th and 60th days of storage. In the chemical analysis; proximate composition (% moisture, % protein, % fat, and % ash), pH and TBA values were determined. The samples were examined for total aerobic plate count (APC), total anaerobes, psychrotrophic bacteria, total coliforms, total staphylococcus/micrococcus count, mould and yeast to observe the hygienic quality of the doner samples. The results of chemical analysis, in general, showed that sucuk doners had higher ash content, pH and TBA values, and all of the doners had higher APC, psychrotrophic bacteria and coliform counts at the beginning compared to 30th and 60th days of storage not only in the raw condition but also in cooked counterparts. The sensory evaluation results indicated that sucuk doners received favorable preferences, therefore, traditional sausage (sucuk) dough application in doner production could be possible without posing any acceptability problems in terms of quality factors compared to traditional beef doners.     

Effect of fat level and ripening temperature on biochemical and sensory characteristics of naturally fermented Turkish sausages (sucuk)

Changes in chemical and sensory characteristics of naturally fermented Turkish sausages during ripening were evaluated for three fat levels (10, 20 and 30%) and two different ripening temperatures, i.e. 20–22 and 24–26 °C. Fat level, ripening temperature and time affected total acidity, free fatty acids (FFA) and thiobarbituric acid (TBA) values. Both higher fat content and higher temperature resulted in higher FFA and TBA values during ripening, indicating high lipolytic and oxidative activity. TBA values showed an increase from the first to the ninth day, but were lower at 20–22 °C than at 24–26 °C. High fat level and temperature adversely affected rancid flavor and overall acceptability.     

Effect of replacing beef fat with hazelnut oil on quality characteristics of sucuk - A Turkish fermented sausage

Turkish fermented sausages (sucuk) were produced by replacing 15, 30 and 50% of beef fat with hazelnut oil incorporated as pre-emulsified with simplesse^® 100 (whey protein powder) Each treatment was formulated to contain 20% total fat and beef fat was the only fat material used in the control (C) group. After 12 days of fermentation and ripening, all sucuk samples had TBA values within acceptable limits (<1.0). Increasing levels of hazelnut oil in sucuk formulation increased penetrometer values (softer texture) and moisture content. Hazelnut oil replacement had a significant effect on redness values of the samples. Cholesterol content decreased progressively as the percentage of hazelnut oil increased in the formulation. Replacement of 50% beef fat with 50% hazelnut oil significantly increased MUFA, PUFA and MUFA + PUFA/SFA ratios. The use of hazelnut oil resulted in significant decreases in the slice appearance, texture and taste scores. However there was no significant difference in the overall acceptability score of samples, except those in which hazelnut oil replaced 15% beef fat, which had the highest score.     

Survival of Helicobacter pylori in artificially contaminated ultrahigh temperature and pasteurized milk

Helicobacter pylori (H. pylori) is a very important bacterial pathogen of humans which may cause gastrointestinal illnesses ranging from gastric and duodenal ulcers to neoplastic diseases such as MALToma and gastric cancer. Transmission via contaminated food is still uncertain but several authors believe this can realistically occur and milk may act as a vehicle of infection. This paper reports the results of H. pylori survival trials in pasteurized and ultrahigh temperature (UHT) milks artificially contaminated and aerobically stored at 4 degrees C. The results obtained showed that the four strains used in this study (H. pylori nat 18-19-20 and H. pylori ATCC 43504), had a progressive reduction in bacterial load with a median survival of 9 days in pasteurized milk and 12 days in UHT milk, with approximate average of initial inoculum of 10(5) and 10(6)cfu/ml, respectively. These findings are very important to clarify the route of transmission of H. pylori to humans via food and for implementation of a correct risk analysis for food safety purposes.     

Survival of Helicobacter pylori in ready-to-eat foods at 4 degrees C

The survival of Helicobacter pylori (NCTC 11638) in various semiprocessed and fresh, ready-to-eat foods, and one raw chicken was studied at 4 degrees C and under aerobic conditions by experimentally inoculating these with 10(4) CFU. Cells were concentrated by two centrifugation cycles followed by plating onto selective blood agar medium made from Wilkins-Chalgren agar supplemented with 5% whole horse blood, and 30 mg/l colistin methanesulfonate, 100 mg/l cycloheximide, 30 mg/l nalidixic acid, 30 mg/l trimethoprim, and 10 mg/l vancomycin. H. pylori was recovered from spiked pasteurized milk and tofu samples up to 5 days and from spiked leaf lettuce and raw chicken up to 2 days. H. pylori could not be recovered from yogurt after any length of storage time. H. pylori is unlikely to grow in foods; however, it may survive in low acid-high moisture environments under refrigeration and pose a possible risk for transmission of infection via foods.     

Investigation of the effect of sumac extract and BHT addition on the quality of sucuk (Turkish dry‐fermented sausage)

The effect of sumac extract and BHT (butylated hydroxytoluene) addition on the quality (pH, colour, biogenic amine, TBARS values and sensory attributes) of sucuk (Turkish dry‐fermented sausage) were investigated during the ripening period. Addition of BHT decreased the TBARS value by about 23.7%, whereas sumac extract decreased it by 42.0%. Sumac extract decreased (P < 0.05) putrescine formation more than BHT addition. However, no significant difference (P > 0.05) was observed in histamine formation for both the sumac extract and BHT‐added recipe. The highest tyramine concentration was observed in a control recipe (R1) prepared without any antioxidants, and the lowest was in the sumac extract‐added recipe (R3) with mean values of about 96.62 and 63.17 mg kg^?1, respectively. The control recipe (R1) was found to be the worst (P < 0.05) sample with respect to overall sensory quality and addition of either sumac extract or BHT increased (P < 0.05) the overall sensory quality of sucuk. The pH and colour attributes of sucuk were not significantly different (P > 0.05) between the addition of sumac extract and BHT. This study demonstrated that sumac extract had more effect on the quality of sucuk during the ripening period, hence it could be easily utilised in sucuk to enhance quality. Copyright © 2006 Society of Chemical Industry     

Effect of Bifidobacterium bifidum fermented milk on Helicobacter pylori and serum pepsinogen levels in humans

Helicobacter pylori infection is an important risk factor for gastric diseases. Some probiotics are useful for suppressing H. pylori infection. Bifidobacterium bifidum YIT 4007 can improve the experimental gastric injury in rats and the disease stages on the gastric mucosa in peptic ulcer patients. We evaluated the fermented milk using a clone (BF-1) having the stronger ability to survive in the product than this parent strain to clarify the in vitro suppressive effect of BF-1 on H. pylori and the in vivo efficacy of BF-1 fermented milk on H. pylori and gastric health. In the mixed culture assay of BF-1 and H. pylori, the number of pathogens was decreased such that it was not detected after 48 h in the Brucella broth with a decrease in pH values. In the cell culture experiment with human gastric cells, the H. pylori infection-induced IL-8 secretion was suppressed by the preincubation of BF-1. In a human study of 12-wk ingestion (BF-1 group, n = 40; placebo group, n = 39) with a randomized double-blind placebo-control design, the H. pylori urease activity and gastric situation were evaluated using a urea breath test (UBT) and the serum pepsinogen (PG) levels as biomarkers for inflammation or atrophy, respectively. In the H. pylori-positive subjects, the difference (ΔUBT) of the UBT value from the baseline value in the BF-1 group (n = 34) was lower than that in the placebo group (n = 35) at 8 wk. The baseline UBT values showed a negative correlation with ΔUBT values at 8 and 12 wk in the BF-1 group but not in the placebo. In the PG-positive subjects classified by the PG test method, the BF-1 group was lower in ΔUBT values than the placebo group at 8 and 12 wk. In the active gastritis class by PG levels, the BF-1 group was lower in their ΔUBT values than the placebo at 8 and 12 wk. The PG I levels in the BF-1 group were lower than the placebo at 12 wk. The PG II levels in the BF-1 group did not change during the ingestion period, but the placebo was increased. The PG I/II ratios slightly decreased from baseline at 12 and 20 wk in the BF-1 and placebo groups. These patterns were also observed in the H. pylori-positive subjects. The improving rates of upper gastrointestinal symptomatic subjects and total symptom numbers in the BF-1 group were higher than those in the placebo. These results indicate that BF-1 fermented milk may affect H. pylori infection or its activity, gastric mucosal situation, and the emergence of upper gastrointestinal symptoms.     

Colour and textural attributes of sucuk during ripening

The sensory (flavour, colour, and ease of cutting scores), colour (Hunter L, a, b, YI, total colour difference, hue angle, chroma, and browning index values) and textural (hardness, adhesiveness, springiness, cohesiveness, gumminess, chewiness, and resilience) attributes of sucuk were followed during the ripening period. Colour scores increased (P<0.05) from score 4 to 6 during the first 3 days of the ripening period and then decreased (P<0.05). The lightness (L values), yellowness (b), and hue angle of sucuk decreased (P<0.05) during the ripening period. The major colour changes occurred between the 5th and 9th days of the ripening period. Pearson correlation test indicates that a positive relationship (P<0.01) exists between a-values and sensory colour scores. The overall sensory scores changed (P<0.05) in parallel to the flavour scores. Hardness, gumminess, and chewiness of sucuk increased (P<0.05) during the ripening period. Strong relationships (P<0.01) were found between hardness and cutting scores. Adhesiveness values of sucuk decreased significantly (P<0.05) about 10 times from -9.3 to -92.6 during the ripening period. Springiness and cohesiveness values decreased during the ripening period, but not significantly (P>0.05). Cutting scores were related (P<0.01) to gumminess (0.921) and chewiness (0.922) values but not to resilience (P>0.05). It was observed that most instrumental colour and textural attributes were in agreement with sensory attributes. These results indicated that instrumental methods could be easily adapted and can be used for evaluation of quality attributes of sucuk during the ripening period.     

Determination of antibiotic susceptibility and decarboxylase activity of coagulase‐negative Staphylococcus and Macrococcus caseolyticus strains isolated from fermented Turkish sausage (sucuk)

The aim of this research was to detect antibiotic susceptibility patterns and amino acid decarboxylase activity of 61 presumptive coagulase‐negative Staphylococcus (CNS) strains from the Turkish dry fermented sausage (sucuk). The presumptive CNS strains were identified at species levels as 21 S. saprophyticus, 16 S. epidermidis, 10 Macrococcus caseolyticus, 4 S. xylosus, 3 S. sciuri, 2 S. hominis, 2 S. warneri, 1 S. cohnii, 1 S. pasteuri, and 1 S. vitulinus by 16S rDNA sequence analysis. S. saprophyticus and S. epidermidis species were found highly resistant to antibiotics than other species. In addition, most of the CNS and M. caseolyticus strains showed multiple antibiotic resistance profiles. None of the CNS and M. caseolyticus strains did not decarboxylate histidine, lysine, or ornithine, but only three CNS strains produced tyramine from tyrosine. A 100% correlation was found between the presence of tdc gene and tyramine production in tyraminogenic strains.

Practical applications

Coagulase‐negative Staphylococcus (CNS) strains play an important role in production of traditional fermented sausages such as sucuk. In this study, S. saprophyticus and S. epidermidis were found the most common isolated CNS species from sucuk. Antibiotic resistance was detected widespread in CNS and M. caseolyticus strains. Most of the CNS strains were found resistant to clinically relevant antibiotics. Antibiotic resistance strains may be dangerous for consumer health. These strains can be a potential reservoir to spread of antibiotic resistance gene between staphylococci and other species of bacteria. In addition, biogenic amine production was not found widespread in CNS strains.     

The use of commercial starter cultures in the production of Turkish semi-dry fermented sausages

 The effects of three different starter cultures (Pediococcus acidilactici, Staphylococcus xylosus plus P. pentosaceus, S. carnosus plus Lactobacillus pentosus) were evaluated during the production of Turkish semi-dry fermented sausages. Sausages were studied during the fermentation phase, after heat processing and after drying for 24 h and 72 h. Chemical and organoleptical results indicated that in the processing of these semi-dry sausages a starter culture of P. acidilactici should be used. The use of this culture significantly reduced the pH, increased the lactic acid content and percentage of total heme pigments converted to the cured pigment and improved the development of the sausages' characteristics, i.e. color, appearance, flavor and general acceptability. Received: 20 February 1998 / Revised version: 7 May 1998     

In vitro screening of lactobacilli with antagonistic activity against Helicobacter pylori from traditionally fermented foods

Helicobacter pylori may cause stomach diseases such as chronic gastritis, peptic ulcer, and gastric cancer, and several studies reported that lactobacilli have inhibitory effects on H. pylori. In this study, 38 Lactobacillus strains were screened for anti-H. pylori activity using in vitro methods, including survivability under the simulated gastric conditions, agar plate diffusion, urease activity, coaggregation, autoaggregation, and hydrocarbon analysis. The results indicate that 2 Lactobacillus strains showed potential anti-H. pylori activity in vitro. Lactobacillus plantarum 18 had the largest zone of inhibition and markedly reduced the urease activity of H. pylori. Lactobacillus gasseri Chen had higher coaggregation rate (58.15%) and hydrophobicity (59.27%) compared with the other strains. Further research is needed to verify the activities of these strains against H. pylori.     

Tarhana as a traditional Turkish fermented cereal food. Its recipe, production and composition

As a fermented product tarhana is the dry form of yogurt-cereal mixture and represents an important part of the diets of many people in Turkey. It is prepared by mixing wheat flour, yogurt, yeast and a variety of cooked vegetables (tomatoes, onions, green pepper etc.), salt, and spices (mint, paprika) followed by fermentation for one to seven days. Generally one part yogurt is mixed with two parts of wheat flour (w/w). In commercial production there are two methods for tarhana making. First method is called straight method and ingredients in the recipe is mixed and kneaded, fermented, dried and finally sieved. Second method is called sour dough method that contains three steps, each one has a different recipe. Throughout fermentation lactic acid bacteria and yeast give the characteristic taste and flavour of tarhana by producing lactic acid, ethanol, carbondioxide and some other organic compounds. Organic acids composed in fermentation period lower the pH (3.4-4.2), and low moisture content (6-10%) is a poor medium for pathogens and spoilage organisms. The nutrient content of tarhana depends upon yogurt and flour ratios as well as some other ingredients, and it is also considered to be a useful high-protein dietary supplement with average 15% protein content. Addition of set yogurt due to high dry matter content and baker's yeast increase protein content and enhances it's amino acid composition.     

Survival of Listeria monocytogenes during the manufacture and ripening of Turkish white cheese

Listeria monocytogenes was enumerated during the manufacture and ripening of Turkish White cheese with particular reference to a) pasteurized milk, b) cheese milk after inoculation with L. monocytogenes (0 h), c) after curd formation (2 h), d) curd after pressing (6 h), e) curd after pH was reduced (17 h), f) curd after salting (32 h), and g) cheeses during ripening. Cheeses were also examined periodically for total solids, moisture and salt contents, pH values and aerobic plate count. An increase in the number of L. monocytogenes was observed during manufacture. Following salting and throughout the storage period, numbers of L. monocytogenes decreased at a rate depending on the salt concentration, starter activity and storage time. The initial microbial number had a significant (P < 0.01) effect on the survival of L. monocytogenes during the storage period.     

Effects of some commercial additives on the quality of sucuk (Turkish dry-fermented sausage)

The effects of some commercial additives on the quality of sucuk (Turkish dry-fermented sausage) were investigated during the ripening and storage periods. Microbial, chemical and sensory changes were followed for 15 days of ripening and 36 days of storage. Aerobic plate count (APC) increased (P < 0.05) from 5.19 to 6.09 log CFU/g during the first 10 days of ripening and afterwards decreased (P < 0.05) to 3.69 log CFU/g. APC and lactic acid bacteria (LAB) changed significantly (P < 0.05) with time and additives. LAB increased (P < 0.05) from 4.62 log CFU/g to about 5.47 log CFU/g during the first 10 days of the ripening period and decreased to 1.79 log CFU/g at the end of storage. Control sucuk without additives had the highest level of mould and yeast counts (5.09 log CFU/g). TBARS values increased gradually (P < 0.05) from 0.61 to 1.73 mg/kg and tyramine concentrations varied from 56.8 to 419 mg/kg. Control sucuk was found to have the lowest overall sensory quality (P < 0.05), and nitrate/nitrite concentration increased (P < 0.05) the overall sensory quality of the sausages. Pearson’s correlation test indicated that there was a link (P < 0.01) between the overall sensory quality and pH, TBARS values, mould and yeast counts, and putrescine concentration.     

Effects of starter cultures and additives on the quality of Turkish style sausage (sucuk)

The effects of starter cultures and additives on the quality of Turkish style sausage (sucuk) were investigated during ripening and storage. Total aerobic plate counts (aerobic bacteria), mould and yeast counts, pH, thiobarbituric acid (TBA) value and biogenic amine formation were followed. Aerobic bacteria increased (P<0.05) during the first 10 days of ripening to 9.26 log CFU/g and they decreased (P<0.05) to 5.70 at the end of the storage. Larger reductions (P<0.05) were observed in sausages made with high levels of potassium sorbate, nitrite and nitrate than in those containing low levels of additives and those without additives at the end of storage. During the first 3 days of ripening, the pH values of all sausages decreased (P<0.05) from 5.98 to about 4.53. Later, the pH values increased slowly, due to decomposition of acids to an approximately constant value of about 5.20. TBA values were higher (P<0.05) in the sausages made without additives than in the others. Sausages prepared using high concentration of additives had lower (P<0.05) concentrations of biogenic amines than the others. Addition of starter culture with high concentration of additives (nitrite, nitrate, α-tocopherol, ascorbic acid, potassium sorbate, potassium pyrophosphate and di-potassium hydrogenphosphate) decreased the formation of biogenic amine.     

茅台酒与幽门螺旋杆菌

通过一些实际例子,证明茅台酒具有治疗胃病的功效。结合幽门螺旋杆菌的基本研究状况及其与胃病间的关系,推断茅台酒对幽门螺旋杆菌具有杀灭或抑制其生长繁殖的作用;指出此方面的相关研究需从茅台酒健康成分及其对人体内环境产生变化等方面开展。（晓文）     

Probiotic lactobacilli and bifidobacteria in a fermented milk product with added fruit preparation reduce antibiotic associated diarrhea and Helicobacter pylori activity

To investigate matrix-specifity of probiotic effects and particularly of the reduction of antibiotics-associated diarrhea, a controlled, randomized, double-blind study was performed, in which 88 Helicobacter pylori-infected but otherwise healthy subjects were given for eight weeks either a) a probiotic fruit yoghurt "mild" containing Lactobacillus acidophilus LA-5 plus Bifidobacterium lactis BB-12, n = 30), b) the same product but pasteurized after fermentation (n = 29) or c) milk acidified with lactic acid (control, n = 29). During week five, a Helicobacter eradication therapy was performed. Helicobacter activity was measured via 13C-2-urea breath tests and antibiotic-associated diarrhoea and other gastrointestinal complaints were recorded by validated questionnaires. In intervention group a, b and c the mean number of days with diarrhoea was 4, 10 and 10 (P<0·05), the frequency of episodes 17%, 7% and 27% (n.s.), and the change in total symptoms score before antibiotics treatment was -1·4 ± 1·1, -1·2 ± 1·1, 2·6 ± 1·1 points/four weeks (P<0·05). All milk products decreased Helicobacter activity by 18 to 45% without significant differences between groups. The observed decrease in Hel. pylori activity seems to be not or not only due to probiotic bacteria but (rather) to components of acidified milk (most probably lactic acid). Fruit-yogurt-like fermented milk products with living probiotic bacteria significantly shorten the duration of antibiotics-associated diarrhoea and improve gastrointestinal complaints. Fruit yogurt-like fermented milk is a matrix suitable for probiotic bacteria.