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An experimental setup was devised to investigate the permeability of cocoa bean seed coat and pulp to key volatile compounds during fermentation. Four labeled compounds (ethyl acetate- d 3, ethyl octanoate- d 15, 2-phenylethanol- d 5, linalool- d 5) and 2 unlabeled (beta-damascenone, delta-decalactone) were chosen for the investigation. The beans (cotyledons), depulped beans, or pulped beans were immersed separately in a concentrated solution of these volatile compounds at 36 or 46 °C for durations ranging from 3 to 120 h. The imbibed beans were dissected, and the cotyledons were analyzed by SPME-GC/MS. The diffusion of volatile compounds from the external solution to the seed was categorized into three groups: (1) not diffusible (ethyl octanoate- d 15); (2) semidiffusible (ethyl acetate); and (3) totally diffusible (2-phenylethanol- d 5, linalool- d 5, beta-damascenone, delta-decalactone). The impact of the yeast on volatile compound diffusion was also investigated by immerging the pulped beans into the same concentrated solution with a yeast starter. Results highlighted the positive role of yeast in the diffusion of volatile compounds. The starter positively contributed to volatile compound diffusion after a transition phase occurring at approximately 48 h of fermentation, enriching the cocoa beans with key aromatic volatile compounds.

This work aims to sort cocoa beans according to chocolate sensory quality and phenolic composition. Prior to the study, cocoa samples were processed into chocolate in a standard manner, and then the chocolate was characterized by sensory analysis, allowing sorting of the samples into four sensory groups. Two objectives were set: first to use average mass spectra as quick cocoa-polyphenol-extract fingerprints and second to use those fingerprints and chemometrics to select the molecules that discriminate chocolate sensory groups. Sixteen cocoa polyphenol extracts were analyzed by liquid chromatography-low-resolution mass spectrometry. Averaging each mass spectrum provided polyphenolic fingerprints, which were combined into a matrix and processed with chemometrics to select the most meaningful molecules for discrimination of the chocolate sensory groups. Forty-four additional cocoa samples were used to validate the previous results. The fingerprinting method proved to be quick and efficient, and the chemometrics highlighted 29 m/ z signals of known and unknown molecules, mainly flavan-3-ols, enabling sensory-group discrimination.

Flavan-3-ols were successfully extracted from cocoa by the Fast-Prep device and analyzed by HPLC-DAD, and their identifications were confirmed by injection of authentic standards. (-)-Epicatechin was the most abundant component with an average of 9.4 mg/g dried cocoa powder. More than 700 cocoa samples were used to calibrate the NIRS. An efficient calibration model was developed to accurately determine any flavan-3-ol compound of ground dried cocoa beans (SEP = 2.33 mg/g in the case of total flavan-3-ols). This performance enabled NIRS to be used as an efficient and easy-to-use tool for estimating the level of targeted compounds. The analysis of the PLS loadings of the model and pure epicatechin spectra gave proof that NIRS was calibrated on an indirect strong correlation resulting in the changes in flavan-3-ols during fermentation and their interaction with some major components, such as proteins. Total flavan-3-ol concentration fell from an average of 33.3 mg/g for unfermented samples to an average of 6.2 mg/g at the end of fermentation. Changes in flavan-3-ol content were dependent upon the origin and highly correlated to the fermentation level expressed as the sum of temperatures (average R(2) = 0.74), a good marker of the fermentation process and of the heterogeneity of the batch.

In greenhouse experiments, Aychade, a fragrant rice variety, was grown under one level of salt solution (EC of 3800 ± 400 μS·cm(-1)) sufficient to induce salt stress in rice. Timing and duration of salt solution application varied according to the growth stages. 2-Acetyl-1-pyrroline (2AP), a characteristic flavor compound of fragrant rice as well as biogenetically related compounds, proline, and γ-aminobutyric acid (GABA) were quantified. Salt treatments induced 2AP synthesis in the leaves, but the increase was often higher in the vegetative phase. This increase was correlated with proline level but not with that of GABA. Interestingly the grains from all the salt treated plants contained significantly higher levels of 2AP (733-998 μg·kg(-1)) than those from the control (592 μg·kg(-1)). The highest 2AP synthesis occurred when the plants were subjected to salt treatment during whole vegetative or reproductive phases. However in the latter case crop yield decreased significantly.

Volatile compounds of cooked rice from scented (Aychade, Fidji) and nonscented (Ruille) cultivars grown in the Camargue area in France were compared to that of a marketed Asian scented one (Thai) by gas chromatography-olfactometry (GC-O) and gas chromatography-mass spectrometry (GC-MS). GC-O analyses of the organic extracts resulted in the perception of 40 odorous compounds. Only two compounds, oct-1-en-3-one and 2-acetyl-1-pyrroline, were almost always perceived. Hierarchical cluster analysis showed that most of the difference between rice odors was linked to quantitative differences with only 11 compounds being specific to some of the rice. Sixty compounds were identified and quantified by GC-MS, including a few new odor-active components. Principal component analysis enabled us to differentiate scented cultivars from a nonscented one, and scented rice cultivars from Camargue from a Thai sample. Calculated odor-active values evidenced that the Thai sample odor differed from that of scented Camargue cultivars because of the degradation of lipids and of cinnamic acid compounds.

This study describes a new and suitable method for the rapid evaluation of rice (Oryza sativa, L.) aroma by analysis of the volatile fraction using solid-phase microextraction coupled with mass spectrometry (SPME/MS). The abundance list of unresolved mass fragments of the SPME extracted volatile fraction formed the "fingerprint" of a rice sample. Fingerprints of 61 rice samples were recorded in duplicate. Pollutants originating from the extraction system induce fingerprint background that could be lowered by careful cleaning of vials and caps and by exclusion of specific mass fragments. A good discrimination between scented and nonscented rice samples was obtained using the SIMCA procedure. Most of the discriminating mass fragments could be directly or indirectly assigned to potential aromatic molecules present in rice.

The formation of volatile compounds from precursors or through chemical rearrangement during heat treatment of bacuri pulp at fruit natural pH were studied using simultaneous distillation/extraction (SDE) technique. An increase of the quantities of oxygenated and hydrocarbon terpenes and, to a lesser degree, aldehydes, was observed after SDE at pH 3, relative to the other extraction methods used, SDE at neutral pH and solid phase extraction (SPE). More particularly, linalool, linalool furanoxides, alpha-terpineol, hotrienol, nerol oxide, nerol, and geraniol were isolated in more important quantities after the first treatment than after the others. These results can be partially explained by the hydrolysis of glycosidically bound compounds previously identified in bacuri. Other pathways such as polyol rearrangements were also involved. The formation of linalool and alpha-terpineol was probably the result of the rearrangement of 2,6-dimethyloct-1-ene-3,7-diol. Moreover, it was assumed that oxidation reactions occurred during SDE at pH 3; more particularly, linalool pyranoxides partially resulted from nonenzymatic oxidation of linalool. When SDE was performed at pH 3, an increase of furfural and 4-methoxy-2,5-dimethyl-3(2H)-furanone was noticed. The modifications of the concentration of aliphatic aldehydes, known as lipid oxidation compounds, and of fatty acid esters were in good agreement with the observed decrease of palmitic and linoleic acid concentrations during this treatment. Moreover, important amounts of 2-acetyl-1-pyrroline were found in the SDE extract recovered at pH 7.