Solvent accessibility limitation by plant matrix compounds in extraction of rutin from Solanum lycopersicum

Abstract

Extraction procedures for plant‐based secondary metabolites are mainly influenced by choice of solvent, particle size and solvent to feed ratio. For developing an extraction protocol design‐of‐experiments or model‐based approaches have widely been used. Botanical aspects such as the influence of side compounds are less investigated. Either for analytical or preparative purposes, knowledge of the underlying extraction mechanisms is required to improve the process development. In this work, we demonstrate the mechanism of accessibility limitation of rutin by side compounds depending on the solvent to feed ratio. Extraction yields of target and side compounds are analyzed to derive correlations. The role of side compounds as limiting factors for target compound accessibility is demonstrated by performing two extraction steps using three different plant species. The maximum extraction yield of rutin is reached using a solvent to feed ratio of at least 300 for all three investigated plant species, while side compounds in liquid state generally affect the extractability of rutin. Phosphatidylcholines are identified as possible accessibility‐limiting compounds. In conclusion, the yields of target and side compounds strongly depend on the solvent to feed ratio, while side compounds cover the target compound in dry matter, reducing its accessibility.