Dried pet food analysis by nearinfrared spectroscopy (NIRS)

Importance of the Topic

Pet food quality assessment is essential for nutritional compliance and regulatory standards. Near-infrared spectroscopy offers a rapid, non-destructive approach to measure moisture, protein, fat and ash in dried pet food, reducing time and labor compared to conventional methods.

Study Objectives and Overview

The main aim is to evaluate NIR spectroscopy for simultaneous determination of key quality parameters in dried dog and cat food. The study included 199 samples from multiple suppliers in both whole and ground forms. Calibration and validation were performed to develop robust predictive models.

Methodology and Instrumentation

Diffuse reflectance spectra were acquired using the OMNIS NIR Analyzer Solid. Samples were placed in a rotating cup to capture uniform spectra. Reference values were obtained by standard ISO methods: moisture (ISO 6496), protein (ISO 5983), fat (ISO 6492) and ash (ISO 5984). Spectral data were averaged automatically and used to build calibration models with external validation.

Instrumentation Used

• OMNIS NIR Analyzer Solid
• Multi-position rotating sample cup
• Pre-calibrated dry pet food model (6.06008.027)

Main Results and Discussion

All four parameters showed strong correlations between NIR predictions and reference methods. Ground samples yielded slightly lower prediction errors than whole samples. Key points:

• Moisture: high correlation coefficients for both sample forms
• Protein: accurate predictions with minimal bias
• Fat and Ash: reliable performance across sample types

Figures of merit confirmed the suitability of NIR models for routine quality control.

Benefits and Practical Applications

NIR spectroscopy enables rapid analysis (approximately one minute for all parameters) compared to hours required by traditional methods. It requires minimal sample preparation and supports on-line or at-line monitoring in production environments. The availability of a pre-calibrated model simplifies implementation further.

Future Trends and Opportunities

Advancements may include:

• Integration with automated production lines for inline quality monitoring
• Expansion of calibration databases using machine learning algorithms
• Application to diverse pet food formulations and other feed matrices
• Linkage with digital quality management and Industry 4.0 ecosystems

Conclusion

This application note demonstrates that NIR spectroscopy with the OMNIS NIR Analyzer Solid provides accurate, fast and cost-effective determination of moisture, protein, fat and ash in dried pet food. Its adoption can streamline quality control workflows and reduce operational workload.

Reference

• ISO 6496: Determination of moisture content
• ISO 5983: Protein determination
• ISO 6492: Fat determination
• ISO 5984: Ash determination
• ASTM D6122: NIR method for moisture, protein, fat and ash