Fast determination of total unbound fat in snack foods using a new fully automated parallel extraction and concentration system

Importance of the topic

Lipid analysis in foods is critical for consumer health and regulatory compliance. Unbound fat content informs nutritional labeling under NLEA and impacts diet-related health issues such as obesity and cardiovascular diseases. Efficient analytical methods support high-throughput testing in food quality control and research environments.

Goals and overview of the study

This study aims to evaluate the effectiveness of the Thermo Scientific EXTREVA ASE system for rapid determination of total unbound fat in snack foods. Performance metrics are compared against the conventional Dionex ASE 350 extractor coupled with the Rocket Synergy 2 evaporator and traditional Soxhlet methods.

Methodology and instrumentation

Sample Preparation:

• Four snack foods purchased locally, ground with diatomaceous earth (ASE Prep DE) in a coffee grinder.
• Samples loaded into 10 mL stainless steel extraction cells fitted with cellulose filters.

Extraction and Concentration:

• EXTREVA ASE system: Fully automated parallel accelerated solvent extraction and evaporation; hexane/isopropanol (60:40) solvent; 125 °C; 200 psi; nitrogen-assisted; 0.6 mL/min flow; 24 mL volume; evaporation to dryness at 70 °C under vacuum.
• Dionex ASE 350 + Rocket Synergy 2: Separate accelerated solvent extraction and manual transfer of extracts to evaporator; similar solvent and temperature conditions; extraction ~20 min; evaporation ~30 min to dryness.

Main results and discussion

Both extraction approaches yielded comparable unbound fat values (16.1–35.3% w/w) with RSDs below 1.6%, aligning with declared label values (14.3–35.7% w/w). The EXTREVA ASE system halved sample processing time (~20 min/sample vs. ~40–45 min/sample) while minimizing solvent use. Automated transition from extraction to evaporation reduced user intervention and improved laboratory throughput.

Benefits and practical applications

• Significant time savings and increased sample throughput suited for routine food lipid analysis.
• Reduced solvent consumption enhances laboratory sustainability and lowers operating costs.
• Automation minimizes manual handling errors and supports consistent analytical performance.

Future trends and potential applications

Advancements may focus on further reduction of evaporation time via optimized vacuum control and integration of AI-driven process monitoring. The EXTREVA ASE platform could be extended to other matrices such as dairy, meat, and processed foods, and adapted for simultaneous extraction of additional analyte classes (e.g., pesticides, vitamins).

Conclusion

The EXTREVA ASE system offers a robust, fully automated solution for determining total unbound fat in snack foods, delivering accuracy comparable to standard methods while doubling analytical throughput and improving laboratory efficiency.

Instrumentation used

• Thermo Scientific EXTREVA ASE Accelerated Solvent Extractor
• Dionex ASE 350 Accelerated Solvent Extractor
• Rocket Synergy 2 Evaporator System
• 60 mL collection vials and 10 mL stainless steel extraction cells

Reference

• Title 21, Parts 100–169, revised April 1, 2013. §101.9, Code of Federal Regulations, US Government Publishing Office, Washington, DC.
• Department of Health and Human Services, FDA, Food labeling: Mandatory status of nutrition labeling and nutrient content revision, Federal Register, 58, 2079 (1993).
• Rowlands JC, Hoadley JE. FDA perspectives on health claims for food labels. Toxicology, 221, 35 (2006).
• AOAC Official Methods of Analysis, 15th ed.; Method 983.23, Association of Official Analytical Chemists, Arlington, VA (1990).
• AOAC Official Methods of Analysis, 17th ed.; Method 945.16, Association of Official Analytical Chemists, Arlington, VA (2002).
• Srinivasan K, Ullah R. US Patent 9,440,166 B2, Method and Device to Extract Analyte from a Sample with Gas Assistance (2016).
• Srinivasan K, Ullah R. US Patent 11,123,655 B2, Apparatus for Parallel Accelerated Solvent Extraction (2021).