Development of a novel tray solar dryer for aquaculture product: Experimental study on drying kinetics and product quality in Eucheuma cottonii seaweed

Fresh Eucheuma cottonii seaweed, with its high moisture content, requires extended open sun drying, leading to potential issues like prolonged drying duration and reduced product quality due to dirt and animal contamination. A novel tray solar dryer specifically designed for drying fresh Eucheuma cottonii seaweed was developed for seaweed farmers to address these issues. The investigation encompassed several aspects, including the assessment of ambient meteorological conditions (solar radiation, temperature, humidity, and wind speed), the solar dryer performance with and without fans (internal temperature and humidity), the study of drying kinetics (drying rate and moisture ratio), and an evaluation of product quality (moisture content and shrinkage) and compared with open sun drying. Furthermore, the study also investigated the effect of employing different tray layers, such as perforated and black high-density polyethylene plastic. The proposed solar dryer reduced the moisture content of fresh Eucheuma cottonii seaweed from 92 % ± 0.4 (wet basis) to a market-acceptable range of 35 % to 40 % (wet basis) within two days, achieving a drying time two days shorter than open sun drying. Using an HDPE plastic layer, the upper tray achieved both the highest temperature and the lowest humidity, measuring 62.1 °C and 9 %, respectively, when a fan was not employed. However, when a fan was utilised, the highest temperature and the lowest humidity were recorded at 56.8 °C and 9 %, respectively. Thus, the utilisation of the forced convection mode provides optimal performance in a solar dryer when drying fresh Eucheuma cottonii seaweed. The study reveals that employing the proposed solar dryer provides better drying kinetics and product quality compared to open sun drying. In conclusion, the proposed solar dryer has demonstrated its superior capability in effectively addressing the challenges associated with open sun drying.