Multi response optimization of waste activated sludge oxidation and azo dye reduction in microbial fuel cell.

Microbial fuel cell technology draws attention with its ability to directly recover electrical energy from various organic materials. In this study, the operating conditions affecting the oxidation-reduction and electricity generation efficiency of MFC were optimized using the Taguchi Experimental Design model. Optimization was carried out for maximum power density, coulombic efficiency, azo dye removal, and COD removal. With the determined optimum conditions (cathode pH of 3.0, cathode oxygen status of anaerobic, anode substrate of pre-treated, external resistance of 100 Ω, cathode electrode type of plain carbon, cathode electrode surface of 22 cm2, cathode conductivity of 20 µs/cm), 177.03 mW/m2 power density, 7.50% coulombic efficiency, 91.26% azo dye removal efficiency and 21.61% COD removal efficiency were obtained. By Pareto analysis, it was determined that the power density, coulombic efficiency and COD removal efficiency were most affected by the substrate type at the anode, and the azo dye removal was most affected by the catholyte pH. The maximum power density and internal resistance of the MFC operated under optimum conditions were determined as 145.11 mW/m2 and 243.30 Ω, respectively by the polarization curve. Cyclic voltammetry was also performed for the electrochemical characterization of MFC operated under optimum conditions. An anodic peak at -183.2 mV and a cathodic peak at -181.2 mV was visible in the CV curve.

Iron Absorption: Factors, Limitations, and Improvement Methods.

Iron is an essential element for human life since it participates in many functions in the human body, including oxygen transport, immunity, cell division and differentiation, and energy metabolism. Iron homeostasis is mainly controlled by intestinal absorption because iron does not have active excretory mechanisms for humans. Thus, efficient intestinal iron bioavailability is essential to reduce the risk of iron deficiency anemia. There are two forms of iron, heme and nonheme, found in foods. The average daily dietary iron intake is 10 to 15 mg in humans since only 1 to 2 mg is absorbed through the intestinal system. Nutrient-nutrient interactions may play a role in dietary intestinal iron absorption. Dietary inhibitors such as calcium, phytates, polyphenols and enhancers such as ascorbic acid and proteins mainly influence iron bioavailability. Numerous studies have been carried out for years to enhance iron bioavailability and combat iron deficiency. In addition to traditional methods, innovative techniques are being developed day by day to enhance iron bioavailability. This review will provide information about iron bioavailability, factors affecting absorption, iron deficiency, and recent studies on improving iron bioavailability.

Fruit Juice Industry Wastes as a Source of Bioactives.

Food processing sustainability, as well as waste minimization, are key concerns for the modern food industry. A significant amount of waste is generated by the fruit juice industry each year. In addition to the economic losses caused by the removal of these wastes, its impact on the environment is undeniable. Therefore, researchers have focused on recovering the bioactive components from fruit juice processing, in which a great number of phytochemicals still exist in the agro-industrial wastes, to help minimize the waste burden as well as provide new sources of bioactive compounds, which are believed to be protective agents against certain diseases such as cardiovascular diseases, cancer, and diabetes. Although these wastes contain non-negligible amounts of bioactive compounds, information on the utilization of these byproducts in functional ingredient/food production and their impact on the sensory quality of food products is still scarce. In this regard, this review summarizes the most recent literature on bioactive compounds present in the wastes of apple, citrus fruits, berries, stoned fruits, melons, and tropical fruit juices, together with their extraction techniques and valorization approaches. Besides, on the one hand, examples of different current food applications with the use of these wastes are provided. On the other hand, the challenges with respect to economic, sensory, and safety issues are also discussed.