Effect of spray drying and fluidized bed drying on whey protein phospholipid concentrate: Microstructural analysis,...

Area of Science:

• Dairy Science
• Food Processing Technology
• Biochemistry

Background:

• Whey protein phospholipid concentrate (WPPC) is a valuable dairy coproduct rich in bioactive compounds.
• Drying is essential for powdered dairy ingredients but can alter microstructure and bioactivity.
• Understanding the impact of drying methods on WPPC is crucial for developing functional ingredients.

Purpose of the Study:

• To investigate the effects of spray drying (SD) and fluidized bed drying (FBD) on WPPC properties.
• To compare lab-scale SD and FBD with industry-scale spray-dried WPPC (I-SDWPPC).
• To evaluate how drying methods influence WPPC microstructure, protein structure, and bioactivity.

Main Methods:

• Comparison of WPPC processed via spray drying (SD) and fluidized bed drying (FBD).
• Inclusion of industry-scale spray-dried WPPC (I-SDWPPC) as a control.
• Analysis of particle size, milk fat globule diameter, microstructure (confocal microscopy), protein secondary structure (FTIR), xanthine oxidase activity, and oxidation markers (carbonyls, LOOH, TBARS).

Main Results:

• FBD-WPPC showed more uniform protein distribution and distinct fat clusters compared to aggregated structures in SD-WPPC and I-SDWPPC.
• FBD-WPPC retained a more native-like protein secondary structure, while I-SDWPPC exhibited the most significant alterations.
• Xanthine oxidase activity was significantly higher in FBD-WPPC, indicating better enzyme stability; lipid and protein oxidation levels did not significantly differ among methods.

Conclusions:

• Fluidized bed drying preserves the microstructure and native protein structure of WPPC more effectively than spray drying.
• Drying method significantly influences the bioactivity, specifically enzyme stability, of WPPC.
• These findings provide insights for optimizing drying processes for functional dairy coproduct powders.