Biophysical, histological, and bioaccumulation properties of Tilapia muscle affected by water pollution with heavy elements and microbes at the El-Rahawy drain in Egypt.

The leakage of sewage and agricultural drains has led to the contamination of freshwater branches with toxic heavy elements. This raises concerns about their toxic effects on aquatic ecosystems, especially on fish. Tilapia is regarded as an important protein source in Egypt and many other countries. The biophysical, nutritional, and histological aspects of water pollution in the El-Rahawy and Al-Qatta locations of the Nile on Nilotic tilapia muscle were evaluated by assessing the level of contamination of Nilotic tilapia fish. The current study showed that water of the Rosetta branch water was polluted with a very high level at El-Rahawy Drain discharge (RD) location, and with a high level at Al-Qatta (Q) location, while El-Rahawy (R) location was polluted with a lower level. The study traced the pollution effects on Tilapia (Nilotic) muscles in the previous locations. Bioaccumulation factor (BAF) showed a high value of all heavy metals in Tilapia muscle at the Q and R locations. Contrary to what was expected, discharge (RD) location contamination caused BAF increment of heavy metals in Tilapia muscles at upstream R location. All these results were compared with measured dielectric parameters of Tilapia muscle samples in the frequency range (0.02-1000) kHz. There was an increase in conductivity (σac), dielectric constant (ε'), dielectric loss (ε″), penetration depth (dp), and dissipated power (PD) values of Tilapia muscle, with increasing pollution level. The values of permittivity at low and high frequencies (ε's & ε'∞) for Tilapia muscle decreased by increasing pollution. Finally, the variation of these parameters, based on that proportionality relationship, can be considered as a physical indicator for fish contamination affected by their environment pollution, although these parameters need further studies in a controlled (qualitatively and quantitatively) polluted media.

Pea peels as a value-added food ingredient for snack crackers and dry soup.

The food industry produces large quantities of waste, which is available in bulk at zero cost. This study aimed to investigate a new method to maximize the protein intake from pea peels and its further utilization as a value-added food ingredient to produce healthy snack crackers and dry soup. Dehydrated green curd of pea peel (DGCPp) with high protein content (35%) was prepared and incorporated into snack cracker and instant soup powder. Wheat flour was substituted with DGCPp to prepare crackers at three substitution levels (5, 10, and 15%) compared to the cracker control sample (100% wheat flour). Increasing the level of this substitution improved the nutritional value of crackers, with highest protein content was in DGCPp crackers (15%). Crackers also had higher contents of mineral and essential amino acids. The physicochemical and sensorial properties of soup samples were significantly influenced by the addition of DGCPp. Higher rehydration value and mineral content (Ca, Mg, Fe, and Zn) were observed in DGCPp soup samples compared to the control sample. Soup samples of all proportions were more acceptable by all the panelists compared with the control sample. With these findings, it can be concluded that DGCPp can be utilized in a variety of food products (such as crackers and soups) with higher nutritive values.