Fatty acid profiles and fat contents of commercially important seawater and freshwater fish species of Turkey: A comparative study

The fat content and fatty acid compositions of edible muscle of commercially important seawater and freshwater fish species were investigated. The fatty acid compositions of seawater fish species were found to be 25.5–39.4% saturated (SFA), 13.2–29.0% monounsaturated (MUFAs) and 25.2–48.2% polyunsaturated acids (PUFAs), whereas the fatty acid compositions of freshwater fish from Lake Seyhan consisted of 28.0–34.6% saturated (SFA), 10.7–22.7% monounsaturated (MUFAs) and 23.2–43.7% polyunsaturated acids (PUFAs). The proportions of n3 PUFAs of seawater fish (ranging from 22.6 for waker to 44.2% for blue fish) were higher than those of n3 PUFAs of freshwater fish (ranging from 11.5% for North African catfish to 28.4% for zander). However, the levels of n6 PUFAs of seawater fish (ranging from 0.43% for blue fish to 14.4% for sea bass) were lower than those of n6 PUFAs of freshwater fish (ranging from 5.27% for kutum to 16.8% for tench). The results showed that fatty acid profiles of most freshwater fish are basically comparable to those of seawater fish as sources of PUFAs.     

The effects of rosemary extract combination with vacuum packing on the quality changes of Atlantic mackerel fish burgers

The effects of the use of antioxidant technology on the quality of mackerel burgers stored at 4 °C were investigated in terms of sensory, biochemical [thiobarbituric acid (TBA), total volatile basic nitrogen (TVB‐N), peroxide value (PV) and free fatty acids (FFA)] and microbiological analyses [total viable count (TVC)]. Fish meat was divided into three groups; the control (C) without rosemary extract, the second group with 0.4% rosemary extracts (Group A) and the third with 0.8% rosemary extracts (Group B). Results showed that the TVB‐N level did not exceed acceptability limit (30–35 mg 100 g^?1) for all groups. TBA value for the control significantly increased from 1.47 to 4.80 MA kg^?1 whereas it slightly increased in treatment groups as the storage time increased. Significantly higher PV and FFA (P < 0.05) were obtained from the control group. Rosemary extract, in combination with vacuum pack was effective in controlling the growth of bacteria and biochemical indices.     

Lipoprotein Subfraction Profile and HDL-Associated Enzymes in Sickle Cell Disease Patients

Although hypocholesterolemia is a reported finding in sickle cell disease (SCD), low-density lipoprotein (LDL)/high-density lipoprotein (HDL) subfractions and HDL-associated enzymes have not been determined in SCD patients. Blood was collected from 38 hemoglobin (Hb)A volunteers and 45 homozygous HbSS patients who had not received blood transfusions in the last 3 months. Serum lipids were measured by automated analyzer while LDL and HDL subfraction analysis was done by continuous disc polyacrylamide gel electrophoresis. Serum levels of cholesteryl ester transfer protein (CETP), lecithin-cholesterol acyltransferase (LCAT), apolipoprotein B (apoB) and apolipoprotein A-1 (apoA-I) were determined by enzyme-linked immunosorbent assay (ELISA). Total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) levels were significantly decreased, while TG levels were significantly increased in SCD patients compared to controls. A significant decrease in intermediate-density lipoprotein (IDL)-C, IDL-B, IDL-A and LDL-1 fractions were seen in SCD patients, while no significant difference was observed in small dense LDL particles. A significant decrease was seen in HDL-large, HDL-intermediate and HDL-small fractions in SCD patients versus controls. Levels of LCAT and ApoA-1 protein measured in SCD patients were significantly lower while no significant difference was observed in CETP and ApoB protein levels compared to controls. The reduction observed in LDL- and HDL-C in SCD patients was reflected as significantly decreased IDL, LDL-1 and HDL-subfractions. Decreased HDL subfractions may possibly lead to the reduced ApoA-1 and LCAT protein levels observed in SCD patients.     

Formation of biogenic amines by Gram-negative rods isolated from fresh,spoiled, VP-packed and MAP-packed herring (<Emphasis Type="Italic">Clupea harengus</Emphasis>)

Bacterial strains (120) were isolated from fresh, spoiled, VP-packed and MAP-packed herring. Identified bacterial strains were investigated for their abilities to produce biogenic amines in histidine, lysine and ornithine decarboxylase broth by a rapid high-performance liquid chromatography (HPLC) method. The microflora of fresh herring was dominantly Pseudomonas (30%), Enterobacteriaceae (23.2%), Vibrio (13.3%) and Moraxella (13.3%) but, the microflora of herring stored in VP and MAP was dominated by species belonging to Vibrio (23.3%) and Moraxella (20%), which indicates that these packaging systems prevented the growth of Pseudomonas and Enterobacteriaceae. In a laboratory medium containing amino acid (histidine, ornithine and lysine), most of bacterial strains produced histamine, putrescine and cadaverine. The highest histidine decarboxylase activities were observed in Klebsiella oxytoca, Hafnia alvei and Proteus vulgaris which produced 396, 232 and 54 mg histamine/L, respectively in histidine-enriched broth. The accumulation of cadaverine by Klebsiella oxytoca and Hafnia alvei was 325 and 208 mg/l, respectively. All strains isolated produced putrescine in an ornithine-enriched broth, ranging from 3 to 249 mg/l. The production of putrescine by Klebsiella oxytoca and Hafnia alvei was 249 and 195 mg/l, respectively. Moraxella spp and Acinetobacter spp did not produce histamine which indicates they did not have histidine decarboxylase activity.     

Evaluation of the potential use of discard species for fish silage and assessment of its oils for human consumption

Waste or by-products contains a substantial amount of nutrients. Fish silage is an alternative way for assessment of fish discards and waste generated in the fish processing industries. The aim of the study was to evaluate the potential use of discard species (Equulites klunzingeri, marine fish and Carassius gibelio, freshwater fish) for fish silage and chemical quality of fish oil extracted from fish silages prepared with acid and fermented methods. Lipid quality of fish oils extracted from fish silages with LAB strains was evaluated in terms of thiobarbituric acid (TBA), peroxide value (PV), p-Anisidine (AV), totox values and fatty acid composition. The results showed that PV, TBA, AV and totox values of all extracted fish oils were within the acceptable limits for edible oils. Recovered fish oils from silage contained high level of polyunsaturated fatty acids (PUFAs), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), serving as a source of good quality fish oil for human consumption.     

Effectiveness of phase I applications for identifying randomly scattered out‐of‐control observations and estimating control chart parameters

Estimation of unknown process parameters with fixed‐size samples are studied in the following. The standard textbook approach for phase I control chart implementation with a Shewhart control chart is evaluated for the case of normally distributed independent observations with random sampling. The charts are simultaneously implemented by generating observations that have a given percentage of randomly scattered out‐of‐control observations. Simulating the phase I steps, where out‐of‐control samples are detected iteratively by determining trial control limits, identifying samples exceeding these limits, and revising the control limits, the standard practice is evaluated in terms of both detection performance and quality of parameter estimates. It is shown that standard phase I control chart implementations with 3‐σ‐limits may perform very poorly in identifying true out‐of‐control observations and providing a reference set of in‐control observations for estimation in some practical settings. A chart design with 2‐σ‐limits is recommended for a successful phase I analysis.