Concordance analysis between estimation methods of milk fatty acid content

Area of Science:

• Analytical Chemistry
• Food Science
• Nutritional Science

Background:

• Milk fatty acids significantly impact human health.
• Accurate determination of milk fat composition is crucial for nutritional and health evaluations.
• Gas chromatography (GC) and Fourier transform infrared (FTIR) spectroscopy are common analytical techniques.

Purpose of the Study:

• To compare the accuracy and reliability of GC and FTIR spectroscopy for determining milk fatty acid content.
• To assess the agreement between GC and FTIR measurements of key fatty acids in milk fat.
• To evaluate the suitability of both methods for analyzing milk fat composition.

Main Methods:

• Fatty acid content was determined using both GC and FTIR spectroscopy.
• Data were compared using Pearson's correlation, linear Bayesian regression, and the Bland-Altman method.
• Analysis focused on individual fatty acids, saturated, unsaturated, monounsaturated, and polyunsaturated fatty acids.

Main Results:

• High correlations (r=0.60-0.92) were observed between GC and FTIR measurements.
• GC generally reported higher values for palmitic acid, oleic acid, unsaturated, and monounsaturated fatty acids compared to FTIR.
• FTIR generally reported higher values for stearic acid, saturated, and polyunsaturated fatty acids compared to GC, with an average bias ranging from -8.65 to 6.91g/100g of fat.
• Despite quantitative differences, 94% of samples fell within concordance limits, indicating consistent variability.

Conclusions:

• Both GC and FTIR spectroscopy can be used to assess milk fat composition, providing similar conclusions regarding sample profiles.
• Quantitative discrepancies between GC and FTIR exist for specific fatty acids and groups.
• The consistent pattern of milk fat composition observed by both methods supports their utility in health-related studies.