ABSTRACT
Due to the recent and ongoing pandemic - COVID-19 - there was an urgency to determine a method to delay the continuously rapid development of the new virus. As a result, Ultraviolet-C (UVC) light, also known as Ultraviolet Germicidal Irradiation (UVGI), has been in higher demand because of its known ability to disinfect quickly and effectively. However, because of its short wavelength/higher energy, either 222nm or 254nm, material degradation is usually much more accelerated than Ultraviolet-A (UVA) or Ultraviolet-B (UVB). At this moment, this study only observed color change when exposing polystyrene to UVC light, and it is believed that this is one of the first studies, if not the first, conducted with this material. Polystyrene was selected because of its availability, abundance of relevant research (ie. UVA/UVB exposure results), and its use in weathering standards. Additionally, since there are no standards specifically about UVC exposure, this preliminary research may provide some direction. © 2022 Society of Plastics Engineers. All rights reserved.
ABSTRACT
Currently, an estimated 20% of the population in Sub-Saharan Africa is food insecure with the incidence of hunger and malnutrition still rising. This trend is amplified by the socio-economic consequences of the COVID-19 pandemic. In contrast, more than a third of the harvestable perishable produce is lost due to a lack of preservation or failure to utilize preservation as is the case for underutilized crops (UCs). Moreover, some of the preservation techniques utilized are poor, leading to the deterioration of food quality, especially the micronutrients. In this study, we thus exemplarily investigated the impact of different drying settings on the quality of two highly nutritious UCs, namely cocoyam and orange-flesh sweet potato (OFSP) (40, 60, and 80 degrees C for cocoyam and 40, 50, 60, and 70 degrees C for OFSP) to deduce the optimum quality retention and further develop a theoretical design of processing units and processing guidelines for decentralized food processing. Drying cocoyam at 80 degrees C and OFSP at 60 degrees C, respectively resulted in a relatively shorter drying time (135 and 210 min), a lower total color difference (2.29 and 11.49-13.92), greater retentions for total phenolics (0.43 mg GAE/100 g(DM) and 155.0-186.5 mg GAE/100 g(DM)), total flavonoid (128 mg catechin/100 g(DM) and 79.5-81.7 mg catechin/100 g(DM)) and total antioxidant activity (80.85% RSA and 322.58-334.67 mg AAE/100 g(DM)), respectively for cocoyam and OFSP. The beta-carotene, ascorbic acid and vitamin A activity per 100 g(DM) of the OFSP flours ranged between 6.91- 9.53 mg, 25.90 - 35.72 mg, and 0.53 - 0.73 mg RAE, respectively.