Characterization of Fish Sauce Aroma‐Impact Compounds Using GC‐MS, SPME‐Osme‐GCO, and Stevens' Power Law Exponents

Abstract

The objectives of this study were to characterize volatile compounds and to determine the characteristic aromas associated with impact compounds in 4 fish sauces using solid-phase micro-extraction, gas chromatography-mass spectrometry, Osme, and gas chromatography olfactometry (SPME-Osme-GCO) coupled with Stevens' Power Law. Compounds were separated using GCMS and GCO and were identified with the mass spectral database, aroma perceived at the sniffing port, retention indices, and verification of compounds by authentic standards in the GCMS and GCO. Aromas that were isolated and present in all 4 fish sauce samples at all concentrations included fishy (trimethylamine), pungent and dirty socks (combination of butanoic, pentanoic, hexanoic, and heptanoic acids), cooked rice and buttery popcorn (2,6-dimethyl pyrazine), and sweet and cotton candy (benzaldehyde). All fish sauces contained the same aromas as determined by GCO and GCMS (verified using authentic standard compounds), but the odor intensity associated with each compound or group of compounds was variable for different fish sauce samples. Stevens' Power Law exponents were also determined using this analytical technique, but exponents were not consistent for the same compounds that were found in all fish sauces. Stevens' Power Law exponents ranged from 0.14 to 0.37, 0.24 to 0.34, 0.09 to 0.21, and 0.10 to 0.35 for dirty socks, fishy, buttery popcorn, and sweet aromas, respectively. This demonstrates that there is variability in Stevens' Power Law exponents for odorants within fish sauce samples.

Identification of odour-active compounds of pasteurised orange juice using multidimensional gas chromatography techniques

“…GC-O has been applied to food and beverage, fragrances, and essential oils analysis (Chin, Eyres, & Marriott, 2012a;Dussort et al, 2012;Eyres, Marriott, & Dufour, 2007;Janzantti & Monteiro, 2014;Qiao et al, 2008;Rouseff et al, 2001). Detection frequency (Dussort et al, 2012;Falcão, de Revel, Rosier, & Bordignon-Luiz, 2008), dilution to threshold (Benzo et al, 2007;Kang & Baek, 2014), and direct intensity (Garruti, Franco, da Silva, Janzantti, & Alves, 2003;Pham, Schilling, Yoon, Kamadia, & Marshall, 2008) are the main GC-O techniques. In particular, detection frequency analysis is based on the assumption that the relative number of subjects detecting an odour at any given retention time during a GC-O run reflects the relative importance of that odour compound.…”

Effect of Enzymatic Protein Deamidation on Protein Solubility and Flavor Binding Properties of Soymilk

“…A sigmoidal relationship between chemical concentration and perceived intensity were also reported in previous studies (Audouin and others 2001; van Ruth 2004). The relationship observed for the plots of the logarithm of concentration of the flavor compound versus logarithm of perceived aroma intensity (Figure 2b and 3b) were linear, and thus followed the Stevens's power law (Kamadia and others 2006; Pham and others 2008). …”

“…From Stevens's power law, the n exponent value (Table 5) (from the slope of the linear section of the plot) indicated the relationship between the perceived magnitude (aroma intensity) and the concentration of a stimulus (flavor compound) (Stevens 1971). From Table 5, all n exponents of vanillin and maltol in both CSM and DSM were less than one, which means the aroma intensity increased only marginally as a function of increasing concentration (Pham and others 2008). The results showed that the n exponents for both vanillin and maltol were higher in DSM than in CSM.…”

Volatile aroma components of Thai fish sauce in relation to product categorization

“…However, the odour‐active compounds give different odour intensities at the same FD value. According to Stephens’ law, the odour intensity perceived depends on threshold value and concentration of an odorant . At one dilution level, the detected odour‐active compounds exhibited different intensities of the odour which vary as their concentration, exponent and proportionality constant .…”