Fish are one of the main sources of protein in Cambodia but they are highly perishable. This requires immediate consumption or processing for later use. In processing, fish drying is very common, but most processors practice traditional drying methods although solar dryers have been introduced, or gradually used, in Cambodia. There is a large variation in terms of drying efficiency due to large differences in solar radiation, temperature, and humidity conditions in traditional drying methods and solar dryers. However, there is limited information on the actual variation in these two systems, which should be documented in Cambodia. Using sensors to monitor micro-climatic changes inside the drying chamber will be useful to improve efficiency and performance. Therefore, the objectives of this research were to (1) design a fish dryer from locally available inputs; (2) determine changes in solar radiation over time; (3) compare relative humidity and temperatures between traditional sun-drying and the solar dryer; (4) determine the relationship among the climatic parameters; and (5) compare some physical, chemical, and biological properties of dried fish in both drying techniques with the Cambodian dried fish standards. The study was conducted in collaboration with a fish processor in the Siem Reap Province between December 2023 and January 2024 using a sensor-mounted solar dryer fabricated by the Royal University of Agriculture to dry fish and compared with traditional sun-drying. Three experiments were carried out from 8:00 to 16:00 following the common drying practices in Cambodia. In each experiment, 80–100 kg of raw giant snakehead, or 56–70 kg of prepared fish (1.04 ± 0.05 kg each fish), was prepared for drying. Data on environmental conditions were measured and analyzed. The results show that the solar dryer had higher temperatures (almost 60 °C) and lower relative humidity (about 20%) during peak hours when compared with traditional sun-drying (36.8 °C and 40%, respectively). In all cases, relative humidity decreased with rising solar radiation and temperatures. The final weight and moisture of dried fish in the solar dryer were lower than those in traditional sun-drying in eight hours. Salmonella was detected with traditional sun-drying but E. coli was not. Bacterial presence may be harmful to human health. Nevertheless, the time spent for drying in both techniques was the same, so future studies should focus on improving ventilation to remove moisture faster out of the solar dryer, which can help with faster drying and more time saving. Hybrid solar dryers should also be considered to maintain high temperatures at night, while bacteria should be counted for safety reasons.

Fish is a vital source of proteins and nutrients and can be eaten in many forms, one of which is dried fish. In Cambodia, fish is mostly dried in traditional ways and can be subject to dust, flies, rain, and weather events, resulting in low-quality products. These issues can be addressed by using solar dryers. Thus, this study was aimed to (1) compare the socio-economic conditions between dried fish processors practicing traditional drying and those using solar dryers, (2) to identify potentials and challenges to dried fish production between the two groups, and (3) to determine the factors affecting income. The study was conducted between May and August 2023, using purposive sampling to select two groups of dried fish processors in three provinces along the river systems in Cambodia. The selection criteria included (1) engagement in year-round dried fish production, (2) at least 100 kg of raw fish dried per month, and (2) willingness to participate in the interviews. Then, 35 dried fish processors that practiced traditional drying and 9 processors that utilized solar dryers were selected. T-tests, chi-square tests, analysis of variance (ANOVA), Likert scale analysis, and multiple linear regression model were used to compare the socio-economic conditions, perceptions, and the factors affecting the income. The results show that the solar dryer group used more labor, produced more dried fish, and had a higher selling price when compared to the traditional drying group. They had more opportunities to attend training and trusted the solar dryer technology. Meanwhile, the traditional drying group preferred direct sun-drying, but dried fish quality was better when solar dryers were used. Experience, total costs, and the use of solar dryers affect the income. In conclusion, using solar dryers tends to produce dried fish of better quality and a higher income, which is good for both health and improved livelihoods of fish producers and sellers.