Sasongko Setia Budi, Hadiyanto H, Djaeni Mohamad, Perdanianti Arninda Mahar, Utari Febiani Dwi
Department of Chemical Engineering, Faculty of Engineering, Diponegoro University, Jl Prof. H. Soedarto, SH, Tembalang, Semarang, 50275, Indonesia.
Heliyon. 2020 Jul 4;6(7):e04338. doi: 10.1016/j.heliyon.2020.e04338. eCollection 2020 Jul.
Onion, a very common season ingredient, is useful as an antioxidant and optimal conditions are required for its drying while ensuring the best quality is retained. This study evaluated the effect of drying temperatures and relative humidity on both drying rate and onion quality. Onions with an average diameter of 20.125 ± 0.025 mm were peeled and sliced into a thickness of 1.233 ± 0.029 mm. They were then dried for 120 min under various temperatures ranging from 40 to 70 °C. Both moisture content and total phenolic compounds were measured and analyzed as responses, and the data obtained were used for estimating the kinetic parameters of drying rate and total phenolic compounds degradation. The results show that the drying kinetics followed Fick's model. Moreover, the total phenolic compounds degradation can be properly expressed using a first-order reaction model, and the optimization using response surface method revealed that the optimum conditions of onion slice drying were achieved at 49.6 °C and relative humidity of 0.65%. These conditions can significantly reduce drying time with phenolic compounds retention of up to 96%.
洋葱是一种非常常见的调味品，作为抗氧化剂很有用，其干燥需要最佳条件，同时要确保保留最佳品质。本研究评估了干燥温度和相对湿度对干燥速率和洋葱品质的影响。将平均直径为20.125±0.025毫米的洋葱去皮，切成1.233±0.029毫米厚的薄片。然后在40至70°C的不同温度下干燥120分钟。测量并分析水分含量和总酚类化合物作为响应指标，所得数据用于估算干燥速率和总酚类化合物降解的动力学参数。结果表明，干燥动力学遵循菲克模型。此外，总酚类化合物的降解可以用一级反应模型恰当地表示，使用响应面法进行优化表明，洋葱片干燥的最佳条件是在49.6°C和相对湿度0.65%下实现的。这些条件可以显著减少干燥时间，同时酚类化合物的保留率高达96%。
