Effect of dehydration and pulsed light treatment on decontamination of minced onions: Microbial safety and physicochemical properties.

Microbial contamination of dehydrated onion products is a challenge to the industry. The study focused on opting for a suitable drying condition for minced onion and exploring the decontamination efficacy of pulsed light (PL) treatment conditions for the dehydrated product. The minced onions were hot air dried at 55-75°C for 280 min. The drying condition selected was 195 min at 75°C with a final water activity of 0.5 and moisture content of 7% (wet basis [w.b.]). The weight losses, browning indexes (BI), shrinkage volumes (%), and thiosulfinate content were considered. The dehydrated product was exposed to PL treatment corresponding to an effective fluence range of 0.007-0.731 J/cm2. A fluence of 0.444 J/cm2 (1.8 kV for 150 s) achieved 5.00, 3.14, 2.96, and 2.98 log reduction in total plate count, yeast and mold count, Bacillus cereus 10876, and Escherichia coli ATCC 43888, respectively. The PL-treated sample (0.444 J/cm2) produced a microbially safe product with no significant difference in the moisture contents (%w.b.) and water activity (aw) from the untreated dehydrated sample. Further, a 30.9% increase in the BI and a 4.25% depletion in thiosulfinate content were observed after PL treatment. An optimum drying combination (75°C for 195 min) of minced onion followed by decontamination using pulsed light treatment at 0.444 J/cm2 fluence satisfies the microbial safety and quality. PRACTICAL APPLICATION: Dehydrated minced onion can be used for dishes requiring low water content and short cooking time. It is helpful during shortages, high price fluctuations, and famines.

Alkaliphiles for comprehensive utilization of red mud (bauxite residue)-an alkaline waste from the alumina refinery.

The mining industry has powered the human endeavor to make life more innovative, flexible, and comfortable. However, it has also led to concerns due to the increasing amount of mining and associated industrial waste. Special attention is highly desired for its proper management and safe disposal in the environment. The problem has only augmented with the increase in the mining costs because of the investments needed for ecological remediation after the mining operation. It is pertinent that the targeted technologies need to be developed to utilize mining and associated industrial waste as a secondary resource to ensure sustainable mining operations. Every perceived waste is a valuable resource that is needed to be utilized to create additional value. In this review, the case of alkaline bauxite residue (red mud)-alumina refinery waste has been discussed at length. The highlight of the proposed work is to understand the importance of alkaliphile-assisted biomining-a sustainable alternative to conventional metal recovery processes. Along with the recovery of metals, pH reduction of red mud is possible through biomining, which ultimately paves the way for its complete utilization. The unique adaptation strategies of alkaliphiles make them more suitable for biomining of red mud through bioleaching, biosorption, and bioaccumulation, which have been discussed here. Furthermore, we have focused on the potential of the indigenous microflora of red mud for metal recovery in addition to its neutralization. The study of indigenous alkaliphiles from red mud, including its isolation and propagation, is crucial for the industrial-scale application of alkaliphile-based technology and has been emphasized.