A study on the performance of corn grain dryer using hybrid solar drying with liquefied petroleum gas

Corn is a widely produced and consumed agricultural product, used as fuel, staple food, and livestock feed. The high level of corn production can lead to potential post-harvest food losses. Drying methods offer a solution to extend the shelf life of a substance. Hybrid solar drying, which combines solar drying with additional heating, particularly using liquefied petroleum gas (LPG), was introduced in this research to ensure faster and more efficient drying processes. The three drying methods compared in this study consist of open sun drying, natural solar drying, and hybrid solar drying. The research results show an average corn grain moisture content of 13.95% over 10.5 hrs, 13.75% over 6 hrs, 13.65% over 7 hrs, 13.45% over 5 hrs, and 13.65% over 4.5 hrs in open sun drying, natural solar drying, and hybrid solar drying with temperature variables of 40°C, 50°C, and 60°C. The average drying rates were 0.212 g/min, 0.364 g/min, 0.318 g/min, 0.439 g/ min, and 0.477 g/min, respectively. The average drying efficiency values for each variable were 2.968%, 4.719%, 5.358%, 5.271%, and 6.037%. In the proximate test, the corn grain moisture content in the hybrid solar drying variable at 60°C was 13.8%, ash was 1.24%, protein was 7.76%, fat was 4.40%, and carbohydrate was 72.8%. For the corn grain color test, the average values obtained were L = 46.48, a = 4.58, and b = 25.37. Meanwhile, the aflatoxin test for dried corn grains showed values of aflatoxin B1, B2, G1, and G2 <0.5 with a total aflatoxin content <2.00. Therefore, hybrid solar drying is recommended over open sun drying and natural solar drying because of its ability to operate even in unfavorable weather conditions, its temperature control capability, its ability to accelerate the drying process, and its capacity to maintain the quality of the material.