In tropical countries, food and agricultural crops need to be kept cool to reduce spoilage and quality losses. Airborne psychrotrophic bacteria and fungi can cause adverse effects on food quality and consumers' health safety. The present study aimed to present a facile and cost-effective approach to remove airborne microbes from indoor air by employing silver (Ag) and zinc oxide (ZnO) to decorate fibrous air filters. A water-based anti-germ solution containing Ag/ZnO nanoparticles was first prepared using high-speed homogenization. Second, a commercially available washable non-woven air filter (thickness 50 mm) was coated by aerosol generated from the mixture using spray coating process. This facile method successfully led to homogeneous coating of active nanomaterials on the filter's surface as unveiled by scanning electron microscope (SEM) with energy dispersive X-ray spectroscopy (EDX). On laboratory scale, the Ag/ZnO air filter was shown to exhibit antibacterial effectiveness against Staphylococcus aureus and Escherichia coli under contact mode following an antibacterial standard method (AATCC 147-2011). Finally, the Ag/ZnO filter was assembled into a commercial air filtration system (670 × 820 × 1420 mm) containing two UVA light lamps (365 nm). The Ag/ZnO air-filtration unit was placed in a 45-m3 cold storage room (4–5 °C) for evaluation of airborne psychrotrophic microbial reduction efficiency. The developed Ag/ZnO air filter reduced the airborne psychrotrophic germs concentrations by ∼50% and its efficiency increased to ∼70% when combined with UVA illumination. Based on these results, a simple and low-cost ZnO/Ag air filter was successfully introduced as an effective strategy for removal of psychrotrophic microbes from indoor air.

Value addition of agro products improves the livelihood opportunities for rural farmers. Cold Storage is one of the techniques to improve the shelf life of agro product. With the increase in the utilization of refrigeration and air cooling using vapour compression refrigeration technology, global warming and ozone depletion due to the refrigerants have also been increased. So, to overcome this problem, several restrictions were placed on the refrigerant by the United Nations Framework Convention on Climate Change (UNFCCC). There is no way to slow down the growth of this technology, so the focus should be shown on finding an alternative. Various studies have been carried out on an alternate refrigeration system. This paper attempts to study the power quality challenges in the conventional vapour compression system. A comparative analysis of vapour compression refrigeration (VCR) and vapour absorption refrigeration (VAR), power factor analysis and temperature measurement on both technologies has also been carried out and reported.

Globally, vaccination plays a vital role in controlling the Covid-19 pandemic. However, the cold supply chain is essential for vaccine storage and logistics services. In a country like India, the last-mile logistics of vaccines is a challenging task. The cold chain is indispensable for the Covid-19 vaccine drive to the rural areas. The demand for cold storage increases rapidly due to the rapid Covid-19 vaccine drive. The conventional cold storage facility has a more significant threat to the grid power quality and environmental impacts. The energy demand and greenhouse gas emission of traditional cold storage lead to global warming. The micro cold storage facility has to be developed rapidly to accelerate the vaccine drive to the last mile of the county with reliable and affordable energy sources. In addition, climate change mitigation is ensured by the renewable energy utilization in the Covid-19 vaccine drive. The proposed novel micro cold storage aims to be silent, clean, mobile, without moving parts, and reliable for the last-mile vaccine logistics as a vaccine carrier to the remote rural areas. This paper deals with the novel design, development, and experimental investigation of solar photovoltaic powered thermoelectric-based micro cold storage as a Covid-19 vaccine carrier for rural areas. The design consideration of Covid-19 vaccine storage has been reported. The experimental results ensure the World Health Organization recommended vaccine storage (i.e., vaccine carrier) temperature range of +2 to +8 °C. Therefore, green energy and refrigeration system provide environmental sustainability by mitigating 700kg of annual carbon emission.

The main objective of this work was to study the effects of probiotic strains, probiotic primary inoculated population, concentrations of spiked diazinon, physiology of probiotic bacteria, fermentation times, and cold storage period in six consecutive stages on diazinon reduction in apple juice. Chemical properties (pH, total acidity, and sugar content), probiotic viability, and diazinon reduction percent were monitored during fermentation and cold storage. Dispersive solid phase extraction (dSPE) followed by gas chromatography-mass spectrometry was used to extract and measure diazinon concentration. Results showed that Lactobacillus acidophilus revealed the highest ability to reduce diazinon in apple juice after fermentation. Inoculation of L. acidophilus at 9 log CFU/mL showed significantly higher diazinon reducing ability than 7 log CFU/mL. L. acidophilus reduced diazinon in apple juice samples containing 1000 μg/L of spiked diazinon significantly higher than those containing 5000 μg/L. Heat-killed (dead) L. acidophilus bacteria reduced less diazinon content at the end of fermentation than viable bacteria. Furthermore, 72 h of fermentation was more effective in diazinon reduction. Spiked diazinon is completely disappeared at the end of cold storage (28 days) in treatments containing L. acidophilus, while the viability of probiotic bacteria required for causing health-promoting properties was maintained in apple juice.

The copper pots with an inner coating layer of tin have been remarkably used in many countries for a long time. In this study, leaching of some metals from tin-lined copper pots into food simulators at different pHs (4, 5.5, 7, and 8.5) during boiling processing (95 °C for 1, 2, and 3 h) or refrigerated storage (4 °C for 1, 2, and 3 days) was investigated. Citric acid and sodium hydroxide were used to adjust the pH of food simulators. The leaching concentrations of metals were analyzed by inductively coupled plasma optical emission spectrometers (ICP-OES). Scanning electron microscopy (SEM) was used to indicate the surface morphological properties of cookware. Based on the preliminary experiments, metals including Al, Sn, Cu, Mn, Fe, Ca, Na, Cr, Mg, and Zn were selected to analyze in acidic treatments. Furthermore, Al, Cu, Sn, Na, and Ca were analyzed for neutral and alkaline ones. Results showed that the boiling temperature for 3 h resulted in a much higher migration of metals compared with cold storage for 3 days. Mn and Cr showed the lowest metal concentration during cooking and cold storage, respectively. The concentration of Sn in acidic simulators was remarkably higher than the other metals during both cooking and refrigerated storage. However, Ca during cold storage, as well as Na during both cooking and cold storage, showed the most migration in alkaline solutions, among the other pHs. An acidic simulator with pH 4 showed the most considerable release of metals from copper pots. SEM results indicated more intense surface corrosion by acidic solution (pH 4) than alkaline one. In general, longer cooking and cold storage durations led to increasing metals release. The migration of the studied metals demonstrates the impurities of the tin layer of these cookwares that may lead to acute and/or chronic diseases.