Investigation and Modeling of Electrical Stunning Parameters of Turkey Using Response Surface Methodology

Abstract: The aim of this work is to evaluate the effects of electrical stunning parameters of turkey on the quality of steak and stew using the response surface methodology. 1584 turkeys were used for the study. The parameters tested were the voltage and pulse. The responses were the sensory quality of steak and stew. The rejection rate varies between 0.23% (steak female) and 56.06% (female stew). Results show that it is possible to obtain a low rejection rates (< 1% for the steak of male turkey) at a voltage of 50 Volts and pulse of 7. In comparison of pulse, voltage remains the most important factor. The optimal conditions selected for the total output of the process obtained from the analysis of the response surfaces are: voltage, from 45 to 47 Volts; pulse from 6.5 to 7 and voltage from 50 to 52 Volts; pulse from 6.8 to 7, respectively for female and male turkeys. Under these experimental conditions, the rejection rates range from 0.23% to 0.80% and from 11.93% to 13.27% respectively for steak and stew. The results show that the voltage and pulse are both the parameters meaning on the global quality of steak and stew

EFFECTS OF DRYING PROCESS ON LIPID QUALITY OF SILVERSIDE (FISH) ATHERINA LAGUNAE

Abstract Changes in lipid quality of silverside during solar and hot air drying process were investigated. Total fatty acid content in silverside was 5.42 g/100g fresh sample. N-3 and n-6 polyunsaturated fatty acids levels were 0.59 and 0.62 g/100g fresh silverside respectively. Therefore, all fatty acid groups increased significantly (p<0.05) within processing with higher levels in experimental drying process. After hot air and solar drying treatments, PV and TBARS of the total lipids increased significantly (p <0.05) to reach 2.58 and 3.41 meq active O /kg oil and 0.87 and 1.27 mg MA/kg oil, respectively

Investigating otolith mass asymmetry in six benthic and pelagic fish species (Actinopterygii) from the Gulf of Tunis

Otolith mass asymmetry can significantly affect the vestibular system functionalities; usually, the X values of mass asymmetry vary between −0.2 and + 0.2 (−0.2 < X < + 0.2). These values can change during a fish life and therefore they are not related to the fish total length. We collected a total of 404 fish specimens from the Gulf of Tunis, including three pelagic species: Sardina pilchardus (Walbaum, 1792) (74 otolith pairs), Trachurus mediterraneus (Steindachner, 1868) (66 otolith pairs), and Chelon auratus (Risso, 1810) (60 otolith pairs) and three benthic species: Gobius niger Linnaeus, 1758 (77 otolith pairs), Mullus barbatus Linnaeus, 1758 (60 otolith pairs), and Trachinus draco Linnaeus, 1758 (67 otolith pairs). The relation between the total length and the otolith mass asymmetry was first calculated and compared, and then was evaluated. The comparison of the otolith mass asymmetry between benthic and pelagic species showed a significant difference (P < 0.05), where the absolute mean value of X does not exceed the critical value (0.2) for all the studied species. No relation has been found between the magnitude of the otolith mass asymmetry and the length in both benthic and pelagic specimens. Environmental factors have an indirect effect on somatic growth and otolith accretion. The significant difference found in this study can be due to the difference between the benthic and pelagic environments