Effects of Slightly Acidic Electrolyzed Water on the Quality of Fresh-Cut Apple

To investigate the effects of a slightly acidic electrolyzed water (SAEW) treatment on the quality of fresh-cut apples during storage, this research used a Box–Behnken design to determine the optimal SAEW treatment conditions. Then, the fresh-cut apple was treated under the optimal condition and subjected to a 13-d storage experiment at 4 °C. For fresh-cut apple treated under the optimal SAEW treatment conditions, the total number of surface colonies was reduced by 2.82 logarithms compared to the control group and the sensory score was 8.73. For the treated fresh-cut apple during storage, the quality of the treated group was significantly greater than the non-treatment group. Thus, the SAEW treatment not only effectively controlled the number of microbes on fresh-cut apple, but also slowed quality deterioration during storage

Effects of Temperature on the Growth Performance, Biochemical Indexes and Growth and Development-Related Genes Expression of Juvenile Hybrid Sturgeon (<i>Acipenser baerii</i>♀ × <i>Acipenser schrenckii</i>♂)

In order to investigate the effects of temperature on the growth performance, biochemical indexes and genes expression in juvenile hybrid sturgeon (Acipenser baerii♀ × Acipenser schrenckii♂), five temperature treatment groups (18 °C, 21 °C, 24 °C, 27 °C, 30 °C) were set in this study. After 25 days of domestication, the specific growth rate (SGR) and relative weight gain rate of juvenile sturgeon increased at first and then decreased with the increase in temperature in the range of 18–30 °C and reached the highest value at 21 °C. A quadratic equation was used to fit the regression equation of SGR and temperature (T). The result showed that the temperature of the maximum SGR is 23.45 °C. Moreover, the expression level of the growth hormone (gh) and the content of blood glucose (GLU) increased significantly at 21 °C, while the expression level of the growth hormone receptor (ghr) in the liver decreased significantly. When the temperature exceeded 27 °C, the thyroid hormone levels were significantly affected, and the levels of total antioxidants (T-AOC) and reduced glutathione (GSH) were significantly higher than those in the control group. In addition, with the increase in temperature, the expression levels of hsp70 and hsp90 in the liver increased significantly, while the expression level of the luteinizing hormone (lh) in the brain decreased significantly. To summarize, the effect of temperature on the growth and development of juvenile sturgeon mainly occurs through the effects of glucose metabolism, thyroid hormone level, total antioxidant capacity and growth-related genes. Therefore, in a temperature range between 21 and 24 °C, juvenile sturgeon can obtain the maximum growth rate and survival rate

Effects of Temperature on the Growth Performance, Biochemical Indexes and Growth and Development-Related Genes Expression of Juvenile Hybrid Sturgeon (Acipenser baerii&#9792; &times; Acipenser schrenckii&#9794;)

In order to investigate the effects of temperature on the growth performance, biochemical indexes and genes expression in juvenile hybrid sturgeon (Acipenser baerii&#9792; &times; Acipenser schrenckii&#9794;), five temperature treatment groups (18 &deg;C, 21 &deg;C, 24 &deg;C, 27 &deg;C, 30 &deg;C) were set in this study. After 25 days of domestication, the specific growth rate (SGR) and relative weight gain rate of juvenile sturgeon increased at first and then decreased with the increase in temperature in the range of 18&ndash;30 &deg;C and reached the highest value at 21 &deg;C. A quadratic equation was used to fit the regression equation of SGR and temperature (T). The result showed that the temperature of the maximum SGR is 23.45 &deg;C. Moreover, the expression level of the growth hormone (gh) and the content of blood glucose (GLU) increased significantly at 21 &deg;C, while the expression level of the growth hormone receptor (ghr) in the liver decreased significantly. When the temperature exceeded 27 &deg;C, the thyroid hormone levels were significantly affected, and the levels of total antioxidants (T-AOC) and reduced glutathione (GSH) were significantly higher than those in the control group. In addition, with the increase in temperature, the expression levels of hsp70 and hsp90 in the liver increased significantly, while the expression level of the luteinizing hormone (lh) in the brain decreased significantly. To summarize, the effect of temperature on the growth and development of juvenile sturgeon mainly occurs through the effects of glucose metabolism, thyroid hormone level, total antioxidant capacity and growth-related genes. Therefore, in a temperature range between 21 and 24 &deg;C, juvenile sturgeon can obtain the maximum growth rate and survival rate

Seasonal Changes in Plasma Hormones, Sex-Related Genes Transcription in Brain, Liver and Ovary during Gonadal Development in Female Rainbow Trout (Oncorhynchus mykiss)

The purpose of this study was to investigate the periodic seasonal changes in endocrine activity and gonadal development of female rainbow trout (Oncorhynchus mykiss) in a high-altitude cold-water environment. The fish were sampled monthly from January to November and the levels of plasma hormones (estradiol (E2), cortisol and thyroid hormones (THS)) and vitellogenin (VTG) were measured by ELISA. Moreover, the transcriptions of sex-related genes in the ovary, brain, and liver were detected by qRT-PCR. The results showed a seasonal fluctuation of plasma hormones and VTG together with the development of the ovary, which reached a peak from August to October. Similarly, the transcription of hypothalamic gonadotropin-releasing hormone-2 (cgnrh-2), hypothalamic gonadotropin-releasing hormone receptors (gnrhr) and follicle-stimulating hormone (fsh) in the brain varied from January to September, but the highest level was detected in September to November. In addition, the transcription of sex-related genes located in the ovary and liver increased significantly during August to October, accompanied by a continuous increase in the gonadosomatic index (GSI) and a decrease in the hepatosomatic index (HSI). Therefore, plasma hormones and sex-related genes regulate the development and maturation of O. mykiss oocytes with the change in seasons and peaked in November. The results of this study provide a reference for improving the efficiency of the artificial reproduction of O. mykiss

Effect of crowding stress on growth performance, the antioxidant system and humoral immunity in hybrid sturgeon

To evaluate effects of crowding stress on the physiological mechanisms of juvenile hybrid sturgeon (♀Acipenser baerii×♂Acipenser schrenckii, 23 ± 1 g body weight), an experiment was assigned to three initial stocking densities in flowing water ponds (LD = 100 and 150 fish/m3; MD = 200 and 250 fish/m3; and HD = 300 and 350 fish/m3) for 60 days. Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was used to identify differential metabolites between different stocking densities. The final weight, weight gain rate (WGR) and specific growth rate (SGR) decreased significantly as the stocking density increased (P < 0.05). Gill filaments incurred injury in the MD and HD groups. Crowding stress increased significantly serum cortisol and glucose levels (P < 0.05), and inhibited the antioxidant capacity. However, stocking density did not affect innate immunity parameters in fish, including complement c3, immunoglobulin M (IgM) and lysozyme (LZM). These negative growth performances to crowding stress mainly involved pathways associated with ascorbate and aldarate metabolism, butanoate metabolism, and fatty acid degradation. The gluconeogenesis and glycogenolysis were activated by the glucagon signaling pathway in order to meet the increased energy expenditure of fish under stress, which played a protective role against lipid peroxidation. Assessment of these factors allows for a more comprehensive understanding of the underlying physiological mechanisms associated with crowding stress in hybrid sturgeon