The drying of food products is an essential step in the preservation of crops and agricultural by-products that serve as raw materials for numerous end applications. Solar drying with phase change materials (PCMs) is an efficient low-energy consumption process in the post-reaping stage, reducing food deterioration. A customized solar dryer setup was assembled using Cudappah (black) stones as the base of the drying chamber to facilitate the absorption of solar energy on its surface. The organic paraffin wax, with a melting point of 60 ℃, was used as PCM in the solar dryer. The novelty of the study is the application of a PCM in a solar dryer to improve the effectiveness of drying and decrease the absolute drying period and the microbial content in the dried coconut. The study compared the drying characteristics between open sun drying and solar drying without and with PCM (100 and 200 g). The fabricated setup was utilised for drying coconut using a PCM-based solar drying method. The coconut was dried from an initial moisture content of 55.5% to a final moisture content of about 9%. The prototype dryer model minimized the use of the workforce, avoided improper drying, and decreased the absolute drying time. A total plate count (TPC) test was conducted to characterize the microbial content in the dried coconut. The microbial count decreased with the use of 200-g PCM as the use of PCM retained the heat for a longer time in the chamber. The drying time of coconut decreased by about 28 and 52 h on using 100 and 200 g of PCM, respectively, compared to open sun drying. The sensory characteristics like colour, taste, flavour, quality, and texture of the solar-dried coconut sample were superior to the sun-dried coconut sample.

Hookah, a popular form of smoking tobacco, has been commonly used in Asia and Africa. However, the widespread consumption of hookah has a major impact on human health being. In addition to health risks, discarding the waste products of hookah would be a serious potential danger for environmental resources. In this study, the waste materials of hookah consumption (water, tobacco, and charcoal) were analyzed for the determination of the metals and PAHs using inductively coupled plasma mass spectrometry (ICP-MS) and gas chromatography-mass spectrometry (GC–MS), respectively. Results showed that the average concentration of iron in different flavors of tobacco had the highest amount (3654.2 ppb). Iron had the maximum concentration among the heavy metals, particularly in the mint flavor (10,863.3 ± 4.1). The highest ƩPAHs were related to the mint flavor (47.48 ± 15.21 ppb). Results showed that the aromatic tobacco available in the Ahvaz-Iran market is polluted by heavy metals. The high consumption of hookah in Ahvaz city and the presence of pollutants in hookah waste materials, apart from health risk aspects, can be potentially regarded as sources of environmental contamination. Therefore, education and preventive measures are necessary for this concern.