A multiscale approach to evaluate the effect of different extraction and pre‐treatment methodologies on physicochemical properties of cashew ( <scp> <i>Anacardium occidentale L</i> </scp> .) nut shell liquid

Abstract BACKGROUND Cashew nutshell liquid (CNSL) is an agro‐industrial residue from cashew production that has gained relevance due to its possibilities to generate valuable by‐products. Although lab‐scale CNSL extraction has been studied in terms of yield and energy efficiency, the effect of industrial‐scale extraction and nut pre‐treatment methods on the physicochemical properties of the extract remains underexplored. Thus, this work focuses on using a multiscale approach to study the relationship between the most common extraction (Soxhlet and mechanical pressing) and pre‐treatment processes (roasting and steaming) with CNSL chemical composition and its physicochemical properties. RESULTS The study revealed minimal variations (&lt;0.5% w/w) on phenolic lipids mass fraction of different CNSL samples. However, Soxhlet extracted samples revealed an increase of 2.9%–6.7% (w/w) of cardanol content, as well as 50% lower viscosity and 34% lower saponification value than pressed CNSL samples. Additionally, the study demonstrated that pre‐treatment operation influences CNSL composition since CNSL from raw nuts exhibits 35% less amount of phenolic lipids than pre‐treated samples. Samples from raw nuts also exhibited vibration of ester groups on their FTIR spectra, which may indicate the presence of diacylglycerols. CONCLUSION The findings demonstrate that while extraction methods have limited effect on CNSL physicochemical properties, nut pre‐treatment markedly alters its chemical nature. By clarifying how pre‐treatment impacts CNSL quality, this work reduces technological barriers for cashew producers and processors, enabling informed selection of efficient methods for transforming CNSL into valuable by‐products, and enhancing the economic and sustainable utilization of this bioresource. © 2025 The Author(s). Journal of Chemical Technology and Biotechnology published by John Wiley &amp; Sons Ltd on behalf of Society of Chemical Industry (SCI).