Quantifying anisotropy in mozzarella cheese using spatially resolved shortwave NIR spectroscopy

Area of Science:

• Food Science
• Materials Science
• Spectroscopy

Background:

• Mozzarella cheese texture and functionality are dictated by its anisotropic structure, formed during the pasta-filata process.
• Traditional mechanical testing methods fail to correlate macroscopic properties with molecular-level structural arrangements.
• Understanding anisotropy is crucial for optimizing cheese properties for various food applications.

Purpose of the Study:

• To introduce and validate spatially resolved shortwave near-infrared spectroscopy (SW-NIRS) as a tool for characterizing Mozzarella cheese anisotropy.
• To establish a correlation between optical measurements and the degree of anisotropy in cheese structure.
• To demonstrate the potential of SW-NIRS for non-destructive evaluation of structure-function relationships in anisotropic food systems.

Main Methods:

• Analysis of 19 designed Mozzarella samples using two SW-NIRS experimental setups: two-axis orthogonal measurements and a spinning sample setup.
• Acquisition of spectral data at varying distances from the illumination source.
• Quantification of spectral variation, scattering, and absorbance using multiplicative scatter correction and regression analysis.

Main Results:

• A high correlation (r² = 0.81) was found between anisotropy and optical measurements obtained via SW-NIRS.
• SW-NIRS effectively captured spectral variations related to the fibrous protein network's orientation.
• The study demonstrated the sensitivity of SW-NIRS to structural differences in Mozzarella cheese.

Conclusions:

• Spatially resolved SW-NIRS is a rapid, non-destructive method for quantifying anisotropy in Mozzarella cheese.
• This technique provides insights into the structure-function relationship at a molecular level.
• SW-NIRS holds promise for analyzing other anisotropic food materials.