Characterization of the Changes in Volatile Flavor Substances of Rice and Rice Bran With Different DOM by...

Area of Science:

• Food Chemistry
• Analytical Chemistry
• Agricultural Science

Background:

• Rice flavor is influenced by volatile organic compounds (VOCs).
• Degree of milling (DOM) significantly alters rice composition and sensory properties.
• Understanding VOC changes during milling is crucial for quality control.

Purpose of the Study:

• To investigate the impact of different degrees of milling (DOM) on VOC profiles in rice and rice bran.
• To identify characteristic VOCs responsible for flavor in rice and rice bran.
• To establish a theoretical basis for optimizing milling processes for desirable rice flavor.

Main Methods:

• Combined headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) and headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS) were used.
• Odor activity value (OAV) analysis was performed to identify key aroma compounds.
• Multivariate statistical analyses, including Principal Component Analysis (PCA) and Partial Least Squares Discriminant Analysis (PLS-DA), were employed.

Main Results:

• A total of 43-73 VOCs were detected in rice and rice bran samples, varying with DOM.
• VOC content fluctuated with DOM, with peak levels in specific rice (R-3) and rice bran (B-4) samples.
• Key aroma compounds, including 2-acetyl-1-pyrroline, were identified, with PLS-DA distinguishing DOM based on VOCs.

Conclusions:

• DOM significantly influences the retention and generation of VOCs, thereby shaping rice and rice bran flavor.
• Sample R-3 represents an optimal DOM for rice aroma, with B-4 (outermost layer) playing a key role in flavor.
• The study provides a theoretical foundation for understanding how milling precision impacts rice flavor quality.