HPLC determination of gamma amino butyric acid (GABA) and some biogenic amines (BAs) in controlled, germinated, and fermented brown rice by pre-column derivatization

• HPLC method for analysis of gamma amino butyric acid and biogenic amines in rice.
• 2-Hydroxynaphthaldehyde was utilized as a pre-column derivatizing reagent.
• Analytes were analyzed in controlled, germinated and fermented rice.
• Concentration of GABA and BAs increase after germination and fermentation processes.

The gamma amino butyric acid (GABA) and biogenic amines (BAs) have great physiochemical importance due to their unique functions in human biological systems. The current study describes the investigation and separation of GABA and BAs including putrescine (PUT), cadaverine (CAD), dopamine (DOP), tyramine (TYRA), histamine (HIST), spermine (SPM) and spermidine (SPD) in some Pakistani brown rice. The GABA and BAs were analyzed in controlled, germinated and fermented conditions by using high performance liquid chromatographic (HPLC) technique after pre-column derivatization on a reversed phase C-8 column with diode-array detection at 230 nm. 2-Hydroxynaphthaldehyde was used as a pre-column derivatizing agent and the analytes were detected as Schiff base derivatives. A linear regression was found within 2.25–34.5 μg/mL for the standards GABA and DOP, 1.15–28.5 μg/mL for standards PUT, CAD, HIST, and 2.50–48.5 μg/mL for standards TYRA, SPD, SPM with the correlation coefficient (r2) in the range of 0.997–0.998. GABA was detected in controlled, germinated and fermented samples, whereas analyzed biogenic amines were below the detection limit in controlled conditions and their concentration increased with the passage of germination time and also detected after the fermentation process. This method could be used for separation and quantification of GABA and other BAs simultaneously in food samples especially in cereal seeds during germination and fermentation to examine their levels.