Pulsed vacuum drying enhances drying efficiency and preserves lignan compounds of Schisandra chinensis fruit extract

This study introduces pulsed vacuum drying (PVD) as an innovative method to improve drying efficiency and product quality for Schisandra chinensis fruit extract. The roles of PVD in enhancing drying kinetics and its mechanisms, preserving lignan compounds, reducing the generation of 5-hydroxymethylfurfural (5-HMF) and lowering energy consumption have been investigated. Results demonstrated that reducing the pulsed vacuum ratio from 14:1 to 4:1 shortened drying time by 40–65 % compared to conventional vacuum drying (VD), while simultaneously decreasing energy consumption and increasing specific moisture extraction rate and energy efficiency. Notably, lower pulsed vacuum ratios reduced 5-HMF concentration and slightly increased lignan retention. Furthermore, micro X-CT analysis revealed that PVD increased the porosity and pore number of the dried extract, suggesting that these structural changes represent the primary mechanism underlying the enhanced drying efficiency. The findings position PVD as a promising drying technique for liquid fruit extract dehydration. • Pulsed vacuum drying was employed to dehydrate fruit extract in liquid state. • Pulsed vacuum drying markedly saved drying time and promoted energy performance. • Pulsed vacuum drying at 4:1 pulsed vacuum ratio greatly preserved lignans compounds. • Pulsed vacuum drying increased porosity and pore number of dried extract.