Carotene location in processed food samples measured by cryo In-SEM Raman.

Area of Science:

• Food Science
• Analytical Chemistry
• Spectroscopy

Background:

• Carotenoids like lycopene and beta-carotene are vital micronutrients found in plant-based foods.
• Understanding their distribution within food matrices is crucial for optimizing nutritional quality and bioavailability.
• Current methods may lack the resolution to pinpoint specific micronutrient locations in complex food structures.

Purpose of the Study:

• To apply Cryo In-SEM Raman for the first time to localize carotenoid compounds within a food matrix.
• To investigate the distribution and state of lycopene and beta-carotene in oil droplets and plant cell structures.
• To assess the potential of this combined technique for analyzing micronutrient behavior in food.

Main Methods:

• Utilized Cryo In-SEM Raman spectroscopy to analyze tomato and carrot-based emulsions with 5% oil.
• Visualized oil droplets and plant cell structures using Cryo In-SEM (Cryogenic environmental Scanning Electron Microscopy).
• Acquired Raman spectra from localized areas to identify specific carotenoid compounds.

Main Results:

• Successfully identified and localized lycopene and beta-carotene within both oil droplets and plant cell walls of the emulsions.
• Obtained distinct Raman spectra confirming the presence of these carotenoids.
• Results suggested that the carotenoids were likely in a non-crystalline state within the food matrix.

Conclusions:

• Cryo In-SEM Raman is a powerful technique for structural characterization and molecular identification of carotenoids in food.
• Understanding carotenoid distribution, particularly their solubility in the oil phase, can inform the design of foods with improved bioaccessibility and nutritional value.
• This approach offers a promising avenue for tackling complex biological and food science problems requiring high spatial and molecular resolution.