ABSTRACT
OBJECTIVE: The objective of this study was to investigate the effect of frying oils (canola, hydrogenated sunflower and soybean oils) available commercially and chill storage on the proximate and fatty acid composition of fried slices of farmed great sturgeon (Huso huso). METHODS: Slices of farmed great sturgeon were fried for four minutes at 160ºC in a deep-fryer using different frying oils (canola, hydrogenated sunflower and soybean oils). The oil-to-slice ratio was 2:1. After frying, the slices were allowed to be air cooled for two minutes prior to analysis. For performing the analysis, each of the abovementioned batches was divided into two groups: one group was analysed immediately after frying and the second group was chill-stored at 4ºC for three days and then analysed. RESULTS: After frying, the moisture content decreased while that of fat increased. Fatty acid composition of the slices is affected by type of frying oil. Frying increased the omega-6-to-omega-3 (n-6:n-3) fatty acid ratio while decreased Eicosapentaenoic Acid (C20:5 n-3) and Docosahexaenoic Acid (C22:6 n-3) contents. Proximate and fatty acid composition of raw slices did not change after chill storage. However, in fried- and chill-stored slices, Eicosapentaenoic Acid and Docosahexaenoic Acid contents decreased, while linoleic acid content increased. CONCLUSION: The fatty acid composition of the fried slices tended to resemble that of the frying oils, indicating fatty-acid equilibrium between oils and slices and, during chill storage, it is influenced by the type of frying oil. Slices fried with canola oil had omega-6-to-omega-3 ratios in the ranges recommended for human health.
OBJETIVO: O objetivo deste estudo foi investigar o efeito de óleos de fritura (canola, girassol hidrogenado e soja) disponíveis comercialmente e do armazenamento a frio em postas fritas de beluga (Huso huso), e na composição centesimal e lipídica. MÉTODOS: Postas de beluga de cativeiro foram fritas por imersão durante quatro minutos a 160ºC utilizando-se óleos de fritura diferentes (canola, girassol hidrogenado e soja). A razão entre óleo e postas foi de 2:1. Após a fritura, permitiu-se que as postas esfriassem a temperatura ambiente por dois minutos antes da análise. Para a análise, cada um dos grupos acima foi dividido em dois subgrupos: um subgrupo foi analisado imediatamente após a fritura e o segundo subgrupo foi armazenado resfriado a uma temperatura de 4ºC por três dias e então analisado. RESULTADOS: Após a fritura, o conteúdo da umidade diminuiu enquanto que da gordura aumentou. A composição dos ácidos graxos das postas foi afetada pelo tipo de óleo utilizado na fritura. A fritura aumentou a razão omega-6 para omega-3 e diminuiu os conteúdos dos Ácidos Eicosapentaenoico (C20:5 n-3) e Docosahexaenoico (C22:6 n-3). As composições centesimal e lipídica das postas cruas não se alteraram após o armazenamento a frio. Porém, os conteúdos de Ácidos Eicosapentaenoico e Docosahexaenoico nas postas fritas e resfriadas diminuíram, enquanto que de ácido linoleico aumentou. CONCLUSÃO: A composição lipídica das postas fritas tendeu à semelhança do óleo utilizado para a fritura, indicando um equilíbrio de ácidos graxos entre os óleos e as postas. A composição lipídica das postas durante o armazenamento a frio é influenciada pelo tipo de óleo de fritura. Postas fritas com óleo de canola continham uma razão de ômega-6 para ômega-3 dentro do intervalo recomendado para a saúde humana.
Subject(s)
Beluga Whale , Lipids , Oils/analysisABSTRACT
This study examined the effect of different starvation periods on hematological parameters including hemoglobin[MCV], hematocrit [MCH], red and white blood cells count and corpuscle indices [MCHC], of cultured juvenile Beluga [Huso huso], with an initial body weight of 45 +/- 0.91g. After adaptation to a dry diet for 10 days group s, with 15 fish in each group, were used for this experiment. Each group was randomly distributed to twelve 500L fiberglass tanks. Each tank had a flow-through system. The fish were exposed to 4 different feeding regimes; Control Group [fed four times daily]; Group 1 [given 2 days of starvation]; Group 2 [given 4 days of starvation]; and, Group 3 [given 8 days of starvation]. Analysis was done at the end of each starvation period by collecting blood from the caudal vein and immediately transporting the samples to the laboratory. The results of the analysis indicated that the different starvation periods did not affect the red blood cell count. The hematocrit value in the Control Group was significantly lower [p<0.05] than the fish group starved for 8 days. MCHC value in the control group was significantly lower [p<0.05] than the fish group starved for 2 days. The hemoglobin concentration, MCV and MCH, did not show any significant difference between the treated groups and the Control Group. Those groups with longer starvation periods showed that the white blood cell count decreased significantly [p<0.05]. It could be concluded that short-term starvation periods weaken the immunological system of cultured juvenile Beluga
Subject(s)
Food Deprivation/physiology , Leukocyte Count , Erythrocyte Count , Beluga Whale , HematocritABSTRACT
Beluga [Huso huso] is one of the most valuable species of sturgeons and many efforts have been made to artificially reproduce, culture and restore this precious species. The objective of this study was to find the effects of garlic essential oil as an immunostimulant on hematological indices and on the cellular immunity system of juvenile belugas. An experiment was organized in which six different diets were fed to belugas including: diet without garlic essential oil and antibiotic, diet with oxytetracycline antibiotic [30 mg/kg], and four diets with various amounts of garlic essential oil [0.05, 0.10, 0.15 and 0.20 g/kg]. Beluga juveniles with an average weight of 24 +/- 2 g were fed these diets for 56 days. At the end of the experiment, hematological indices were determined. The blood coagulation time and mean corpuscular hemoglobin [MCH] indices increased in the groups treated with garlic essential oil. Significant increases in lymphocyte counts were observed in groups fed 0.05, 0.10 and 0.15 g/kg garlic essential oil as compared with the antibiotic and control groups. A significant decrease in the blood neutrophil count was observed in the belugas fed 0.15 and 0.20 g/kg garlic essential oil compared with the other treatments. In conclusion, these results showed that adding garlic essential oil increases the blood coagulation time, the hemoglobin content of red blood cells, lymphocyte numbers, and decreases eosinophils. Significant improvements of the immune system and of the physiological condition were observed in juvenile belugas receiving garlic essential oil compared with the control and the antibiotic treatments. It can therefore be used as a suitable replacement for oxytetracycline in the diet of juvenile belugas