Tissue storage affects lipidome profiling in comparison to in vivo microsampling approach

Area of Science:

• Analytical Chemistry
• Marine Biology
• Biochemistry

Background:

• Lipid profiling is crucial for understanding fish muscle quality and health.
• Traditional extraction methods can be destructive and may alter lipid profiles during sample processing and storage.
• In vivo sampling offers a potential alternative for minimally invasive lipid analysis.

Purpose of the Study:

• To evaluate the efficacy of in vivo solid-phase microextraction (SPME) for analyzing lipid profiles in living fish muscle.
• To compare the lipid profiles obtained via in vivo SPME with those from ex vivo SPME and solid-liquid extraction (SLE) on stored samples.
• To assess the impact of storage on lipid profiles and highlight the advantages of in vivo sampling.

Main Methods:

• Low-invasive in vivo SPME using mixed-mode fibers inserted into fish muscle for 20-minute extractions.
• Desorption of analytes from SPME fibers using an optimized solvent mixture.
• Comparison of in vivo SPME results with ex vivo SPME and SLE performed on fish muscle stored for one year.

Main Results:

• In vivo SPME detected a significantly higher number of molecular features compared to ex vivo SPME and SLE.
• Ex vivo analysis of stored samples showed a tenfold decrease in detected molecular features.
• In vivo microsampling identified distinct classes of bioactive lipids, such as fatty acyls, absent in ex vivo/SLE analyses.

Conclusions:

• In vivo SPME is a highly advantageous technique for comprehensive lipid profiling of fish muscle.
• Storage significantly alters the unbound lipid fraction, making in vivo sampling critical for accurate assessment.
• This method preserves the integrity of the lipid profile, revealing bioactive compounds missed by traditional approaches.