Abstract: The aim of the current study was to identify optimum process parameters for the vacuum drying of honeysuckle. The effects of heating temperature, drying pressure and material loading on drying characteristics were explored through single factor experiments. Meanwhile, two mathematical regression models were fitted with required drying time or chlorogenic acid content as a function of temperature, pressure and material amount. Both models had excellent goodness of fit. Multi-target nonlinear optimization indicated that the optimum vacuum drying parameters were drying temperature of 63.6 ℃, drying pressure of 800 Pa and material loading (a single layer) of 40 g, resulting in the highest comprehensive evaluation of required drying time and chlorogenic acid content, which were 215 min and 3.34%, respectively. Vacuum drying can allow the production of high-quality dried honeysuckle in a short time.

Key words: honeysuckle, vacuum drying, mathematical model, optimization