Analysis of Volatiles in Food Products

The evaluation of volatiles in food is an important aspect of food production. It gives knowledge about the quality of foods and their relationship to consumers’ choices. Alcohols, aldehydes, acids, esters, terpenes, pyrazines, and furans are the main chemical groups that are involved in aroma formation. They are products of food processing: thermal treatment, fermentation, storage, etc. Food aroma is a mixture of varied molecules. Because of this, the analysis of aroma composition can be challenging. The four main steps can be distinguished in the evaluation of the volatiles in the food matrix as follows: (1) isolation and concentration; (2) separation; (3) identification; and (4) sensory characterization. The most commonly used techniques to separate a fraction of volatiles from non-volatiles are solid-phase micro-(SPME) and stir bar sorptive extractions (SBSE). However, to study the active components of food aroma by gas chromatography with olfactometry detector (GC-O), solvent-assisted flavor evaporation (SAFE) is used. The volatiles are mostly separated on GC systems (GC or comprehensive two-dimensional GCxGC) with the support of mass spectrometry (MS, MS/MS, ToF–MS) for chemical compound identification. Besides omics techniques, the promising part could be a study of aroma using electronic nose. Therefore, the main assumptions of volatolomics are here described.

Essential Oil Profile Diversity in Cardamom Accessions From Southern India

The essential oil of cardamom capsules is a high-value ingredient in foods, beverages, perfumery, and traditional medicines. It is responsible for the characteristic aroma of cardamom. The present study aimed to evaluate essential oil yield and chemical constituents of 22 diverse accessions of cardamom. A total of 20 g of the cured capsules were hydrodistilled in a Clevenger apparatus for 3 h in three replications. The amount of essential oil yield ranged from 4.5 to 9.5%, indicating a substantial variation in this feature among the accessions. The GC/MS analysis results discovered 24 constituents that constituted 98.1–100% of total essential oil. The main fractions were found to be oxygenated monoterpenes (40.7–66.7%), monoterpene hydrocarbons (23.1–58.6%), and sesquiterpenes (0.1–2.0%). Among the monoterpenoids, the predominant constituents were α-terpinyl acetate (29.9–61.3%) followed by 1,8-cineole (15.2–49.4%), α-terpineol (0.83–13.2%), β-linalool (0.44–11.0%), and sabinene (1.9–4.9%). Two sesquiterpene constituents, cardinen and nerolidol and p-cresol (a phenol derivative) were also identified. The compositional data were subjected to euclidean-distance-based similarity analysis, which showed two major clusters. The major constituents of cardamom essential oil (CEO) are 1,8-cineole, α-terpinyl acetate, sabinene, and β-linalool that can be used in food, aroma, and pharmaceutical applications.

Adaptive Expansion of Taste Neuron Response Profiles by Congruent Aroma in Drosophila

Pairing of food aroma with selected taste can lead to enhanced food flavor and eating euphoria, but how cross-modal sensory combinations are integrated to increase food reward value remains largely unclear. Here we report that combined stimulation by food aroma and taste drastically increased appetite in well-nourished Drosophila larvae, and the appetizing effect involves a previously uncharacterized smell-taste integration process at axon terminals of two Gr43a gustatory neurons. Molecular genetic analyses of the smell-taste integration reveal a G protein-mediated tuning mechanism in two central neuropeptide F (NPF) neurons. This mechanism converts selected odor stimuli to NPF-encoded appetizing signals that potentiate Gr43a neuronal response to otherwise non-stimulating glucose or oleic acid. Further, NPF-potentiated responses to glucose and oleic acid require a Gr43a-independent and Gr43a-dependent pathway, respectively. Our finding of adaptive expansion of taste neuron response profiles by congruent aroma reveals a previously uncharacterized layer of neural complexity in food flavor perception.