Submitted to: Proceedings of Florida State Horticultural Society
Publication Type: Abstract Only
Publication Acceptance Date: 2/28/2004
Publication Date: N/A
Technical Abstract: Mango fruit (cv. Tommy Atkins), were homogenized, and sampled for volatile analysis by static headspace method using an electronic nose (e-nose) with metal oxide coated or uncoated sensors and gas chromatography (GC) equipped with a polar carbowax column and a flame ionization detector. Dilution of homogenate and homogenate volume was analyzed to determine effect on e-nose and GC headspace measurements. Mango homogenate (1.0, 1.5, and 2.0 mL) was diluted with DI water to 50, 25, and 12.5% of original concentration. The resulting e-nose signal was analyzed by Principal Component Analysis (PCA) or Discriminant Factorial Analysis (DFA), which resulted in grouping by dilution factor, regardless of sample size. A combination of 2.0 mL and 25% dilution of mango homogenate were determined to be optimal. These results were compared to analysis of 13 characteristic mango volatiles by gas chromatography (GC) headspace analysis of the mango homogenate for the same volume/dilution combinations. Concentration of volatiles in the headspace generally increased with volume, however, methanol, a-copaene and a-caryophyllene did not change with either dilution or sample volume. Acetone and p-cymene did not change with dilution, but increased slightly with volume, while ethanol and a-terpinolene decreased with dilution, but were not affected by volume. The increase in headspace concentration was not directly proportional to the homogenate volume, indicating matrix effect on aroma partitioning into the headspace, which varied for different compounds. A large volume injected into the e-nose (2000 µL) was necessary to get ample signal and reproducible results for intact fruit sealed in buckets.