An improved method for the purification of milk oligosaccharides by graphitised carbon-solid phase extraction

Area of Science:

• Food Chemistry
• Analytical Chemistry
• Biochemistry

Background:

• Milk oligosaccharides (OS) are bioactive compounds with health benefits.
• Efficient extraction of OS is crucial for their analysis and quantification.
• Current methods for isolating OS from lactose using solid phase extraction (SPE) lack formal optimization studies.

Purpose of the Study:

• To optimize solid phase extraction (SPE) conditions for improved purification of milk oligosaccharides (OS).
• To evaluate the efficacy of different washing solutions in removing lactose while retaining OS.
• To compare the performance of the optimized SPE method against standard techniques.

Main Methods:

• Modification of established solid phase extraction (SPE) protocols.
• Testing low concentrations of acetonitrile (ACN) and trifluoroacetic acid (TFA) for solid phase washing.
• Quantification of lactose removal and OS retention using the modified SPE technique.

Main Results:

• A novel SPE washing solution of 4% ACN/0.1% TFA significantly enhanced lactose removal compared to water washing.
• The optimized SPE method demonstrated improved retention of various milk oligosaccharides (OS).
• Differential behavior was observed between acidic and neutral OS during the extraction process.

Conclusions:

• The developed SPE technique offers improved extraction efficiency for bovine milk OS.
• This method is particularly beneficial for applications where prior lactose hydrolysis is not required.
• The findings contribute to more effective analysis and utilization of bioactive milk oligosaccharides.