Precise separation of flavor constituents from tobacco extracts via tailored nanofiltration membranes

Abstract

Tobacco extract derived from tobacco leaves contains a broad range of bioactive compounds with significant industrial value, yet their structural diversity and overlapping molecular weights pose challenges for selective separation. In this work, a four-stage membrane cascade system, integrating ultrafiltration with three custom-designed nanofiltration (NF) membranes featuring precisely tuned molecular weight cut-offs (MWCOs), was developed to separate the targeted compounds from authentic tobacco extract. Results demonstrated that nicotine was gradually enriched with up to 97 % rejection, while flavor compounds ranging from 90 to 400 Da were selectively retained based on molecular sieving in the four-step membrane cascade system. Following filtration with a ∼342 Da MWCO membrane, the flavor compounds Rishitin (336 Da) and Butyl octyl phthalate (334 Da) were completely retained; subsequent filtration with a ∼180 Da MWCO membrane enabled 100 % retention of β-Violetol (194 Da) and Megastigmatrienone (190 Da); and flavor compounds with 90∼160 Da molecular weights were effectively retained using a ∼92 Da MWCO membrane at final stage. In contrast, low-molecular-weight (<90 Da) compounds exhibited lower retention due to their small size and weak membrane interactions. This membrane-based approach enables efficient and scalable purification of tobacco extract, offering new opportunities for clean processing and high-value utilization in the tobacco industry.