Characterization of Key Odorants in Scallion Pancake and Investigation on Their Changes during Storage

To characterize key odorants in scallion pancake (SP), volatiles were extracted by solvent extraction-solvent assisted flavor evaporation. A total of 51 odor-active compounds were identified by gas chromatography-olfactometry (GC-O) and chromatography–mass spectrometry (GC-MS). (Z/E)-3,6-Diethyl-1,2,4,5-tetrathiane was detected for the first time in scallion food. Application of aroma extract dilution analysis to extracts showed maltol, methyl propyl disulfide, dipropyl disulfide and 2-pentylfuran had the highest flavor dilution (FD) factor of 4096. Twenty-three odorants with FD factors ≥ 8 were quantitated, and their odor active values (OAVs) were calculated. Ten compounds with OAVs ≥ 1 were determined as the key odorants; a recombinate model prepared from the key odorants, including (E,E)-2,4-decadienal, dimethyl trisulfide, methyl propyl disulfide, hexanal, dipropyl trisulfide, maltol, acetoin, 2-methylnaphthalene, 2-pentylfuran and 2(5H)-furanone, successfully simulated the overall aroma profile of SP. The changes in odorants during storage were investigated further. With increasing concentrations and OAVs during storage, hexanal became an off-flavor compound.

Sensory-Based Identification of Aroma-Active Compounds in Hotpot Seasoning before and after Boiling

Boiling, the most frequent edible way to hotpot seasoning (HS), exerts a significant impact on the aroma of HS. The present study employed, for the first time, a novel switchable system between GC-O-MS and GC×GC-O-MS (SGC/GC×GC-O-MS) to study the aroma compounds of HS and hotpot seasoning boiling liquid (HSBL). A total of 79 aroma compounds and 56 aroma-active compounds were identified. The aroma extract dilution analysis (AEDA) was used to analyze the differences between the key aroma-active components in the HS and HSBL. The results showed that 13 aroma-active components were significantly affected by boiling, such as D-limonene, methional, and linalool. Moreover, a total of 22 key aroma-active components were identified through the odor activity values (OAVs) calculation. Of them, (E)-2-octenal (fatty) and linalool showed a significant difference, suggesting them to be the most critical aroma-active compounds in the HSBL, and HS, respectively. Finally, the correlation between key aroma-active compounds and the sensory properties of HS and HSBL was studied. These results demonstrated that the OAVs of key aroma-active compounds could characterize the real information of samples through bidirectional orthogonal partial least squares (O2PLS). The analysis results were consistent with the sensory evaluation results.

Estudio químico del aroma y bioactividad de la fruta del pepino dulce (Solanum muricatum)

Los compuestos volátiles activos olfativamente en el aroma de la fruta del pepino dulce (Solanun muricatum) se extrajeron mediante la técnica de extracción de aroma asistido por disolventes (solventassisted flavor evaporation, SAFE), se analizaron por cromatografía de gases acoplada a olfatometría (CGO), y cromatografía de gases acoplada a espectrometría de masas (CG/EM) y se compararon con estándares. Los compuestos con más influencia en el aroma de la fruta se diferenciaron mediante el análisis por dilución del extracto de aroma (aroma extract dilution analysis, AEDA). Con base en el cálculo del valor de la actividad del olor (odor activity value, OAV) se identificaron como compuestos de impacto de la fruta el E-6-nonenal (nota acuosa), el E-2-nonenal (nota verde-pepino), el hexanal (nota verde), el nonanal (nota verde-pepino) y la 1-penten-3-ona (nota etérea). También se estudiaron in vitro algunas de las propiedades biofuncionales de la fruta: la actividad antihipertensiva mediante la inhibición de la enzima convertidora de angiotensina-I (ECA-I) y la actividad antihipercolesterolémica con base en la inhibición de la 3-hidroxi-3-metilglutaril-coenzima A (HMG-CoA) reductasa. Se encontró que la fruta presenta una actividad inhibitoria de la ECA-I promisoria (IC50=3,72 ± 0,19 ppm), ya que se obtuvo un valor mucho menor que el obtenido para el control positivo (lisinopril). También se evidenció con el tiempo que el extracto de la fruta inhibió la actividad de la HMG-CoA reductasa con una cinética comparable a la del control positivo (pravastatina). Con estos resultados, la fruta de S. muricatum se convierte en una candidata potencial para el desarrollo de alimentos funcionales.

Characterization of the Key Aroma-Active Compounds in Yongchuan Douchi (Fermented Soybean) by Application of the Sensomics Approach

Yongchuan douchi is a traditional fermented soya bean product which is popular in Chinese dishes due to its unique flavor. In this study, the key aroma-active compounds of Yongchuan douchi were characterized by the combined gas chromatography–olfactometry (GC–O) and gas chromatography−mass spectrometry (GC–MS) with sensory evaluation. In total, 49 aroma compounds were sniffed and identified, and 20 of them with high flavor dilution factors (FD) and odor activity values (OAVs) greater than one were screened by applied aroma extract dilution analysis (AEDA) and quantitated analysis. Finally, aroma recombination and omission experiments were performed and 10 aroma-active compounds were thought to have contributed significantly including 2,3-butanedione (butter, cheese), dimethyl trisulfide (garlic-like), acetic acid (pungent sour), acetylpyrazine (popcorn-like), 3-methylvaleric acid (sweaty), 4-methylvaleric acid (sweaty), 2-mehoxyphenol (smoky), maltol (caramel), γ-nonanolactone (coconut-like), eugenol (woody) and phenylacetic acid (flora). In addition, sensory evaluation showed that the flavor profile of Yongchuan douchi mainly consisted of sauce-like, sour, nutty, smoky, caramel and fruity notes.