Product diversification is needed to increase selling and marketing prices. One of them is the African catfish sausage product. Liquid smoke has been used commercially by the food industry. This study aimed to determine the physical and chemical properties of smoked African catfish after adding different concentrations of liquid smoke and immersion duration. The chemical analysis measured the levels of protein, fat, and phenol. The results showed that sausage with a concentration of 20% liquid and soaking for 30 minutes was the best treatment with a protein content of 43.8 ± 0.34%, a fat of 12.33 ± 0.61%, and phenol 292.74 ppm. Determination of the compound using GC-MS found that the most dominant compound in the smokeless sausage was 2-hexanone, 3,3 dimethyl with a relative concentration of 32.42%. The dominant compound in the besttreated sausage was Furan, tetrahydro-2,2-dimethyl- with a relative concentration of 19%. Liquid smoke penetration is clearly visible in the microstructure of smoked sausages, both in the best-treated smoked sausages and commercial sausages. Scanning Electron Microscope (SEM) magnification of 2.500x shows that the best emulsified smoked sausages have a flatter structure, smaller droplets, and are more refined than smokeless sausages or commercial smoked sausages.

The water stream in Desa Kejapanan, Pasuruan, East Java, Indonesia used as a source of water for households and field irrigation is indicated to experience heavy metal contamination. The purpose of this study is to determine the type and concentration of metals in the water stream that is contaminated with metal washing waste. The concentration of heavy metals in water and sediments was tested using the Atomic Absorption Spectrophotometer (AAS) method. In this case, the physical and chemical components of the water measured were color, temperature, pH and DO. Meanwhile, the data of heavy metal concentration was tested using ANOVA and was analyzed descriptively. The data were analyzed using SPSS version 16.0 software. The test results point out that the concentration of mercury (Hg) is ranged from 0.028±0.002 mg/L to 0.036±0.005 mg/L while lead (Pb) is in between 0.492±0.009 mg/L and 0.665±0.007 mg/L, cadmium (Cd) in between 0.142±0.011 mg/L and 0.161±0.004 mg/ L, zinc (Zn) in between 0.737±0.006 mg/L and 0.763±0.004 mg/L), and copper (Cu) in between 0.318±0.004 mg/L and 0.369±0.002 mg/L. It is known that Zn has the highest concentration of metals compared to other metals while the highest concentration of all types of metals (Hg, Pb, Cd, Zn, and Cu) occurs in the sample S2. The water stream is indicated to have been contaminated by heavy metals (Hg, Pb, Cd, Zn, Cu) because the concentrations of these metals have exceeded the maximum qualification both in water and sediments.

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Mercury is a heavy metal that has the highest toxicity. The toxicity of mercury will increase at the time of entry into the water. This study aims to determine the percentage of death Tubifex tubifex exposed to HgCl2 and determine LC50-48 hours of mercury in Tubifex tubifex worms. The study was divided into two stages, preliminary test and definitive toxicity acute test (LC50-48 h). Concentrations are used to test toxicities on a logarithmic scale. Observations were made every 24 hours for 48 hours. Mercury was detected by Atomic Absorption Spectrophotometer (AAS) method. The results showed that the increase in Tubifex tubifex mortality was directly proportional to the increase in HgCl2 concentration. The use of probit obtained LC50-48 h at a mercury concentration of 83.15 ± 3.89 μg / L, can be categorized into heavy metals with high toxicity. The tendency of toxicity decreases with the length of exposure time.

Highlight ResearchIndicated that white feces at Vanammei appeared along with the appearance of the disease besides its main trigger that is Vibrio sp.Increase the availability of carbon for photosynthesis process of phytoplankton.Clinical symptom of shrimp attacked by white feces disease is indicated by a change in intestine.AbstractShrimp disease that currently causes economic loss to shrimp farmers is White Feces Disease (WFD). This disease appeared due to several factors, such as poor pond management, unhealthy shrimp seed, and poor water quality which resulted in the appearance of Vibrio sp. bacteria and Dinoflagellate. This study aimed to analyze the cause of WFD outbreak in vannamei shrimp pond. The study method through direct experiment was applied in shrimp pond. Sampling was performed three times in each feeding tray to collect ten shrimps. Overall, sampling was performed twice a week. The Sample Survey Method was used to collect sample in this study. Result of study showed that clinical symptom was observed through changes in pattern and behavior of vannamei shrimp during culture. However, this observation resulted in insignificant data. Vannamei shrimp infected WFD tended to swim slower and often rose to the surface with body color turned red. Moreover, total organic matter (TOM) increased on week-7 along with the increasing growth of plankton, particularly from the Dinoflagellate group. However, bacterial growth of Vibrio sp. on week-7 was insignificant, yet many shrimps were found dead with white feces during that period. The result of analysis indicated that white feces disease was caused by Dinoflagellate besides the main trigger, namely, Vibrio sp.