Characterization of desi ghee obtained from different extraction methods using Raman spectroscopy

Area of Science:

• Food Science
• Analytical Chemistry
• Spectroscopy

Background:

• Desi ghee, a clarified butter, is a staple in South Asian cuisine.
• Traditional extraction methods may affect the nutritional profile of ghee.
• Raman spectroscopy offers a non-destructive method for molecular characterization.

Purpose of the Study:

• To characterize desi ghee extracted from cow and buffalo milk using different methods.
• To differentiate between cow and buffalo ghee based on their molecular composition.
• To evaluate the impact of extraction methods on the retention of key compounds.

Main Methods:

• Raman spectroscopy with 532 nm and 785 nm laser wavelengths.
• Analysis of ghee samples extracted via direct cream (DC), milk butter (MB), and milk skin (MS) methods.
• Statistical analysis using Principal Component Analysis (PCA) to identify spectral differences.

Main Results:

• Cow ghee exhibited distinct beta-carotene bands (1005, 1156, 1520 cm⁻¹) differentiating it from buffalo ghee.
• The DC method retained higher beta-carotene in cow ghee compared to MB and MS methods.
• MB method showed higher conjugated linoleic acid (CLA) and fatty acid content in cow ghee than MS.
• DC and MS methods retained more CLA and fatty acids in buffalo ghee than MB.

Conclusions:

• Raman spectroscopy effectively distinguishes cow and buffalo ghee based on molecular signatures.
• Extraction methods significantly influence the concentration of beta-carotene, CLA, and fatty acids in ghee.
• The DC and MB methods are superior for preserving specific beneficial compounds in cow and buffalo ghee, respectively.