Department of Zoology, University of Ilorin Ilorin, Nigeria.
Department of Physics, University of Ilorin Ilorin, Nigeria.
Food Sci Nutr. 2014 May;2(3):244-50. doi: 10.1002/fsn3.101. Epub 2014 Mar 7.
This study was done to evaluate the drying performance, efficiency, and effectiveness of five different types of improved low-cost solar driers in terms of moisture loss from two tropical African fish species Clarias gariepinus (African sharp tooth catfish) and Oreochromis niloticus (Nile tilapia) and testing the organoleptic characteristics of the dried samples. The driers used were made from plastic, aluminum, glass, glass with black igneous stone, and mosquito net, with traditional direct open-sun drying as a control. A significant (P < 0.05) decrease in weight resulting from moisture loss in the two fish species was observed in all the driers, with the highest reduction occurring in the glass drier containing black stone. The rate of weight loss was faster in the first 4 days of drying with black stone-inserted glass drier showing the fastest drying rate with a constant weight in C. gariepinus attained on the 11th day and in O. niloticus on the eighth day. The slowest drier was plastic where a constant weight of the species were recorded on and 13th day and 11th day, respectively. Volunteers were used to assess the organoleptic characteristics of the dried samples and they showed lowest acceptability for the open-sun drying, while samples from the glass drier containing black stone had the highest acceptability in terms of the taste, flavor, appearance, texture, odor, palatability, and shelf-life. The low-cost solar driers were effective found in removing water from the fish resulting in significant loss of weight and moisture. The highest drying time, efficient performance, drying effectiveness, and high acceptability of the organoleptic parameters of the dried products from the black stone-inserted glass drier were due to the ability of the glass and the black stone to retain, transmit, and radiate heat to the fish sample all the time (day and night). These low-cost driers are simple to construct, materials for its construction readily available, easy to maintain and operate, hygienic in use, reliable, effective, occupies less area, dry products faster with increased shelf-life, save man-hour, user-friendly, use renewable energy, protect the drying samples from filthiness, wetness, and invasion by pests, insects, and microbes, with well-dried, high-quality, and better preserved final products. The adoption and use any of these low-cost solar driers by artisanal fishermen and general household in sub-Saharan Africa will not only help in reducing post catch losses, but also ensure food safety and security as there is abundant solar energy in these sub-Saharan African tropical countries for the operation of the driers.
这项研究旨在评估五种不同类型改进型低成本太阳能干燥器在两种非洲热带鱼类（非洲尖齿鲶鱼和尼罗河罗非鱼）的水分损失方面的干燥性能、效率和效果，并测试干燥样品的感官特征。所使用的干燥器由塑料、铝、玻璃、带黑色火成岩的玻璃和蚊帐制成，以传统的直接露天干燥作为对照。在所有干燥器中，两种鱼类的体重都显著（P<0.05）下降，这是由于水分流失所致，其中含有黑色火成岩的玻璃干燥器的体重下降幅度最大。在干燥的前 4 天内，体重下降速度较快，插入黑色火成岩的玻璃干燥器的干燥速度最快，在第 11 天达到了 C. gariepinus 的恒定重量，在 O. niloticus 的第 8 天达到了恒定重量。最慢的干燥器是塑料，在第 13 天和第 11 天，这两种鱼类的体重才达到了恒定。志愿者被用来评估干燥样品的感官特征，他们对露天干燥的可接受性最低，而来自带黑色火成岩玻璃干燥器的样品在味道、口感、外观、质地、气味、口感和保质期方面的可接受性最高。这些低成本的太阳能干燥器有效地从鱼类中去除水分，导致显著的体重和水分损失。由于玻璃和黑色火成岩能够一直（白天和黑夜）保留、传递和辐射热量给鱼样，因此插入黑色火成岩的玻璃干燥器的最高干燥时间、高效性能、干燥效果和干燥产品感官参数的高可接受性。这些低成本的干燥器结构简单，其建筑材料易得，易于维护和操作，使用卫生，可靠，有效，占地面积小，干燥产品速度快，保质期长，节省工时，用户友好，使用可再生能源，保护干燥样品免受污垢、潮湿和害虫、昆虫和微生物的侵害，最终产品干燥良好、质量高、保存更好。撒哈拉以南非洲的手工渔民和普通家庭采用和使用这些低成本的太阳能干燥器，不仅有助于减少捕捞后损失，而且还能确保食品安全，因为这些撒哈拉以南非洲热带国家有丰富的太阳能可供干燥器运行。
