Label-Free Fried Starchy Matrix: Investigation by Harmonic Generation Microscopy

Area of Science:

• Food Science
• Microscopy
• Biochemistry

Background:

• Traditional methods for analyzing food microstructure often require sample destruction.
• Identifying and locating specific components like starch and oil within complex food matrices can be challenging.

Purpose of the Study:

• To develop and demonstrate a non-destructive method for analyzing the microstructure of fried starchy foods.
• To detect and map starch granules and oil distribution within a fried matrix.
• To perform topography analysis of food products.

Main Methods:

• Utilized harmonic generation microscopy, a non-linear optical technique.
• Employed specific fluorescent probes (Safranin O for starch, Nile red for oil) for targeted labeling.
• Integrated fluorescence signals with Second Harmonic Generation (SHG) and Third Harmonic Generation (THG) signals.
• Performed sequential scanning with specific emission filters for signal superposition.

Main Results:

• Successfully mapped starch granules using SHG and Safranin O fluorescence.
• Investigated food product topography using THG, independent of fluorescent probes.
• Achieved label-free microstructure investigation of starch granules and oil distribution.
• Demonstrated the ability to obtain starch granule mapping and topography without destructive sample preparation.

Conclusions:

• Harmonic generation microscopy offers a powerful, non-destructive approach for food microstructure analysis.
• This label-free methodology is highly promising for investigating a wide range of starchy food products.
• The technique enables simultaneous visualization of biochemical components and surface topography.