Analysis of free fatty acids in whey products by solid-phase microextraction

Area of Science:

• Food Science
• Analytical Chemistry
• Dairy Microbiology

Background:

• Free fatty acids (FFAs) are crucial indicators of lipid breakdown in dairy products.
• Understanding FFA profiles in whey is essential for assessing product quality and stability.
• Cheddar cheese starter cultures can influence the biochemical composition of whey.

Purpose of the Study:

• To investigate the effect of specific Cheddar cheese starter cultures on free fatty acid (FFA) levels in liquid whey.
• To quantify FFAs in experimentally produced whey and commercial whey ingredients.
• To assess the impact of storage on FFA concentrations in whey.

Main Methods:

• Solid-phase microextraction (SPME) technique for FFA extraction and analysis.
• Quantitation of FFAs using response factors relative to an internal standard.
• Verification of linearity across a wide concentration range for accurate measurement.

Main Results:

• Whey produced with *Lactococcus lactis* subsp. *lactis* exhibited the highest total FFAs, notably lauric, myristic, and palmitic acids.
• Oleic, linoleic, and palmitic acids significantly decreased during whey storage.
• Commercial whey ingredients showed a linear increase in FFAs with rising protein content, except for whey protein isolate.

Conclusions:

• Starter culture selection critically influences FFA profiles in whey.
• Storage conditions lead to significant alterations in specific FFAs.
• SPME is a valuable tool for rapid FFA analysis in whey, aiding further quality and stability research.