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O2 Kg (o2 + kg)
Kinds of O2 Kg Selected AbstractsEffects of drying process on biochemical and microbiological quality of silverside (fish) Atherina lagunaeINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 6 2010Salah Selmi Summary Changes in biochemical and microbiological quality of silverside during two drying process were investigated. Total fatty acid and amino acid contents in silverside were 5.42 and 10.9 g 100 g,1 fresh sample, respectively, in which, palmitic acid and glutamic acid were the most abundant. N-3 and n-6 polyunsaturated fatty acids (PUFA) levels were 0.59 and 0.62 g 100 g,1 fresh silverside respectively. After hot air and solar drying treatments, Peroxide value and thiobarbituric acid reactive substances of the total lipids increased significantly (P < 0.05) to reach 2.58 and 3.41 meq active O2 kg,1 oil and 0.87 and 1.27 mg MA kg,1 oil, respectively. Fatty acid profile of non-polar lipid remains unchanged during experimental drying process. However, PUFA (% of total fatty acids) of polar lipid decreased significantly (P < 0.05) during both drying process with lower levels in solar drying process. Drying conditions had a significant effect on the microbiological quality. Therefore, mesophiles and total coliforms increased within drying treatment with higher counts in solar drying process. [source] Effect of feeding level and feeding frequency on specific dynamic action in Silurus meridionalisJOURNAL OF FISH BIOLOGY, Issue 1 2005S. J. Fu The effect of feeding level (FL; 0·5 to 4% dry diet mass per wet fish body mass) and feeding frequency (once every 4 days to twice per day) on postprandial metabolic response was investigated in southern catfish Silurus meridionalis at 27·5° C. The results showed that there was no significant difference in the specific dynamic action (SDA) coefficient among the groups of different feeding levels (P > 0·05). The duration increased from 26·0 to 40·0 h and the peak metabolic rate increased from 207·8 to 378·8 mg O2 kg,1 h,1 when the feeding level was increased from 0·5 to 4%. The relationship between the peak metabolic rate (RP, mg O2 kg,1 h,1) and FL could be described as: RP = 175·4 + 47·3 FL(r2 = 0·943, n = 40, P < 0·001). The relationship between the SDA duration (D, h) and FL could be described as D=30·97FL0·248 (r2=0·729, n=40, P < 0·001). [source] Endurance swimming of European eelJOURNAL OF FISH BIOLOGY, Issue 2 2004G. Van Den Thillart A long-term swim trial was performed with five female silver eels Anguilla anguilla of 0·8,1·0 kg (c. 80 cm total length, LT) swimming at 0·5 body lengths (BL) s,1, corresponding to the mean swimming speed during spawning migration. The design of the Blazka-type swim tunnel was significantly improved, and for the first time the flow pattern of a swim tunnel for fish was evaluated with the Laser-Doppler method. The velocity profile over three different cross-sections was determined. It was observed that 80% of the water velocity drop-off occurred over a boundary layer of 20 mm. Therefore, swim velocity errors were negligible as the eels always swam outside this layer. The fish were able to swim continuously day and night during a period of 3 months in the swim tunnel through which fresh water at 19° C was passed. The oxygen consumption rates remained stable at 36·9 ± 2·9 mg O2 kg,1 h,1 over the 3 months swimming period for all tested eels. The mean cost of transportation was 28·2 mg O2 kg,1 km,1. From the total energy consumption the calculated decline in fat content was 30%. When extrapolating to 6000 km this would have been 60%, leaving only 40% of the total energy reserves for reproduction after arriving at the spawning site. Therefore low cost of transport combined with high fat content are crucial for the capacity of the eel to cross the Atlantic Ocean and reproduce. [source] Thermal tolerance and metabolic physiology among redband trout populations in south-eastern OregonJOURNAL OF FISH BIOLOGY, Issue 2 2004K. J. Rodnick Streamside measurements of critical thermal maxima (Tcrit), swimming performance (Ucrit), and routine (Rr) and maximum (Rmax) metabolic rates were performed on three populations of genetically distinct redband trout Oncorhynchus mykiss in the high-desert region of south-eastern Oregon. The Tcrit values (29·4 ± 0·1° C) for small (40,140 g) redband trout from the three streams, and large (400,1400 g) redband trout at Bridge Creek were not different, and were comparable to published values for other salmonids. At high water temperatures (24,28° C), large fish incurred higher metabolic costs and were more thermally sensitive than small fish. Ucrit(3·6 ± 0·1 LF s,1), Rr(200 ± 13 mg O2 kg,0·830 h,1) and metabolic power (533 ± 22 mg O2 kg,0·882 h,1) were not significantly different between populations of small redband trout at 24° C. Rmax and metabolic power, however, were higher than previous measurements for rainbow trout at these temperatures. Fish from Bridge Creek had a 30% lower minimum total cost of transport (Cmin), exhibited a lower refusal rate, and had smaller hearts than fish at 12-mile or Rock Creeks. In contrast, no differences in Ucrit or metabolism were observed between the two size classes of redband trout, although Cmin was significantly lower for large fish at all swimming speeds. Biochemical analyses revealed that fish from 12-mile Creek, which had the highest refusal rate (36%), were moderately hyperkalemic and had substantially lower circulating levels of free fatty acids, triglycerides and albumin. Aerobic and anaerobic enzyme activities in axial white muscle, however, were not different between populations, and morphological features were similar. Results of this study: 1) suggest that the physiological mechanisms that determine Tcrit in salmonids are highly conserved; 2) show that adult (large) redband trout are more susceptible to the negative affects of elevated temperatures than small redband trout; 3) demonstrate that swimming efficiency can vary considerably between redband trout populations; 4) suggest that metabolic energy stores correlate positively with swimming behaviour of redband trout at high water temperatures; 5) question the use of Tcrit for assessing physiological function and defining thermal habitat requirements of stream-dwelling salmonids like the redband trout. [source] Relationships between metabolic rate, muscle electromyograms and swim performance of adult chinook salmonJOURNAL OF FISH BIOLOGY, Issue 4 2003D. R. Geist Oxygen consumption rates of adult spring chinook salmon Oncorhynchus tshawytscha increased with swim speed and, depending on temperature and fish mass, ranged from 609 mg O2 h,1 at 30 cm s,1 (c. 0·5 BL s,1) to 3347 mg O2 h,1 at 170 cm s,1 (c. 2·3 BL s,1). Corrected for fish mass, these values ranged from 122 to 670 mg O2 kg,1 h,1, and were similar to other Oncorhynchus species. At all temperatures (8, 12·5 and 17° C), maximum oxygen consumption values levelled off and slightly declined with increasing swim speed >170 cm s,1, and a third-order polynomial regression model fitted the data best. The upper critical swim speed (Ucrit) of fish tested at two laboratories averaged 155 cm s,1 (2·1 BL s,1), but Ucrit of fish tested at the Pacific Northwest National Laboratory were significantly higher (mean 165 cm s,1) than those from fish tested at the Columbia River Research Laboratory (mean 140 cm s,1). Swim trials using fish that had electromyogram (EMG) transmitters implanted in them suggested that at a swim speed of c. 135 cm s,1, red muscle EMG pulse rates slowed and white muscle EMG pulse rates increased. Although there was significant variation between individual fish, this swim speed was c. 80% of the Ucrit for the fish used in the EMG trials (mean Ucrit 168·2 cm s,1). Bioenergetic modelling of the upstream migration of adult chinook salmon should consider incorporating an anaerobic fraction of the energy budget when swim speeds are ,80% of the Ucrit. [source] Use of a spouted bed to improve the storage stability of wheat germ followed in paper and polyethlyene packagesJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 8 2005Füsun Yöndem-Makasc Abstract Stabilization of wheat germ by heating in a spouted bed for 180,540 s with air at 140,200 °C was studied. The lipase activity decreased by 6,65%. Wheat germ processed at 200 °C for 360 s was ranked highest in sensory evaluation, described as having ,a golden color' and ,nutty flavor', and its lipoxygenase activity had decreased by 91.2%. This product and raw wheat germ were stored in paper, polyethylene and vacuum-packed polyethylene pouches at 5 °C, room temperature (18,26 °C) and 40 °C, and the moisture contents, water activities, free fatty acid contents and peroxide values were followed for 20 weeks. The increases were faster in paper pouches than in the polyethylene ones; vacuum packaging in polyethylene did not bring about significant improvement. The peroxide values of raw samples exceeded 10 meq O2 kg,1 oil after 3,23 days while those of the processed samples stored at room temperature or 5 °C were still less than 10 after 20 weeks. The free fatty acid content and peroxide value changes were expressed by zero order kinetics, resulting in similar activation energies for the raw and processed samples. Copyright © 2005 Society of Chemical Industry [source] Size-related oxygen consumption and ammonia excretion of Eurasian perch (Perca fluviatilis L.) reared in a recirculating systemAQUACULTURE RESEARCH, Issue 1 2009Vlastimil Stejskal Abstract Oxygen consumption (OC) and ammonia excretion rates (AE) of perch were measured under commercial-like conditions (temperature 23.3 °C) in both fed (F) and feed-deprived groups (D). Measurements were taken in triplicate in six sized batches of perch ranging from 44.8 to 336.2 g. The mean daily OC was 288.3,180.6 mg O2 kg,1 h,1 for group F fish ranging in size from 44.8 to 279.4 g body weight. The mean daily AE expressed as total ammonia nitrogen (TAN) was 13.8,5.2 mg TAN kg,1 h,1 in the same groups. Daily peaks of OC in group F perch were observed 6 h after the onset of feeding for each size group with relatively stable values up to the end of feeding. Peaks of daily AE in group F perch were observed 10 h after the onset of feeding in each size group, with a rapid decrease up to 16 h after onset. In group D, OC was 181.1,110.5 mg O2 kg,1 h,1 in the weight range 57.9,336.2 g. The daily mean AE was 1.7,0.5 TAN kg,1 h,1 in this group. No dramatic peaks of OC and AE were observed in group D perch. [source] | |||||||||||||