A Further Tool To Monitor the Coffee Roasting Process: Aroma Composition and Chemical Indices

Coffee quality is strictly related to its flavor and aroma developed during the roasting process, that, in their turn, depend on variety and origin, harvest and postharvest practices, and the time, temperature, and degree of roasting. This study investigates the possibility of combining chemical (aroma components) and physical (color) parameters through chemometric approaches to monitor the roasting process, degree of roasting, and aroma formation by analyzing a suitable number of coffee samples from different varieties and blends. In particular, a correlation between the aroma composition of roasted coffee obtained by HS-SPME-GC-MS and degree of roasting, defined by the color, has been researched. The results showed that aroma components are linearly correlated to coffee color with a correlation factor of 0.9387. The study continued looking for chemical indices: 11 indices were found to be linearly correlated to the color resulting from the roasting process, the most effective of them being the 5-methylfurfural/2-acetylfuran ratio (index)

Chemometric Modeling of Coffee Sensory Notes through Their Chemical Signatures: Potential and Limits in Defining an Analytical Tool for Quality Control

Aroma is a primary hedonic aspect of a good coffee. Coffee aroma quality is generally defined by cup tasting, which however is time-consuming in terms of panel training and alignment and too subjective. It is challenging to define a relationship between chemical profile and aroma sensory impact, but it might provide an objective evaluation of industrial products. This study aimed to define the chemical signature of coffee sensory notes, to develop prediction models based on analytical measurements for use at the control level. In particular, the sensory profile was linked with the chemical composition defined by HS-SPME-GC-MS, using a chemometric-driven approach. The strategy was found to be discriminative and informative, identifying aroma compounds characteristic of the selected sensory notes. The predictive ability in defining the sensory scores of each aroma note was used as a validation tool for the chemical signatures characterized. The most reliable models were those obtained for woody, bitter, and acidic properties, whose selected volatiles reliably represented the sensory note fingerprints. Prediction models could be exploited in quality control, but compromises must be determined if they are to become complementary to panel tasting

Artemisia umbelliformis Lam. and Génépi Liqueur: Volatile Profile as Diagnostic Marker for Geographic Origin and To Predict Liqueur Safety

Artemisia umbelliformis, commonly known as “white génépi”, is characterized by a volatile fraction rich in α- and β-thujones, two monoterpenoids; under European Union (EU) regulations these are limited to 35 mg/L in <i>Artemisia</i>-based beverages because of their recognized activity on the human central nervous system. This study reports the results of an investigation to define the geographical origin and thujone content of individual plants of <i>A. umbelliformis</i> from different geographical sites, cultivated experimentally at a single site, and to predict the thujone content in the resulting liqueurs through their volatile fraction. Headspace solid phase microextraction (HS-SPME) combined with gas chromatography–mass spectrometry (GC-MS) and non-separative HS-SPME-MS were used as analytical platforms to create a database suitable for chemometric description and prediction through linear discriminant analysis (LDA). HS-SPME-MS was applied to shorten analysis time. With both approaches, a diagnostic prediction of (i) plant geographical origin and (ii) thujone content of plant-related liqueurs could be made

Time-of-addition assays with <i>S</i>. <i>desoleana</i> EO.

<p>A) Vero cells were treated with EO prior to virus infection (pre-treatment), during the infection period (during infection), or after infection (post-treatment). Data are presented as % of control. Values are means ± SEM of three independent experiments performed in duplicate. B) The histograms show the percentage of plaque area and plaque number of treated wells compared to that of untreated wells as a function of the concentration in the post-treatment assay. C) The images show representative plaques in Vero cells. The pictures and histograms shown are representative of many analyzed plaques, ranging from 15 to 25 per condition. * P< 0.0001.</p

Antiviral activity against HSV-2.

<p>Antiviral activity against HSV-2.</p

Chemical composition (expressed as g/100g) of <i>S</i>. <i>desoleana</i> essential oil and its fractions.

<p>Chemical composition (expressed as g/100g) of <i>S</i>. <i>desoleana</i> essential oil and its fractions.</p

Antiviral activity against HSV-2 acyclovir resistant.

<p>Antiviral activity against HSV-2 acyclovir resistant.</p

Time-of-addition assays with SD1 fraction.

<p>A) Vero cells were treated with SD1 fraction prior to virus infection (pre-treatment), during the infection period (during infection), or after infection (post-treatment). Data are presented as % of control. Values are means ± SEM of three independent experiments performed in duplicate. B) The histograms show the percentage of plaque area and plaque number of treated wells compared to that of untreated wells as a function of the concentration in the post-treatment assay. C) The images show representative plaques in Vero cells. The pictures and histograms shown are representative of many analyzed plaques, ranging from 15 to 25 per condition. * P< 0.0001.</p

Virus inactivation assay 10⁵ pfu of HSV-2 were incubated with 190 μg/ml of <i>S</i>. <i>desoleana</i> EO for 0 or 2 h at 37°C.

<p>The mixtures were then titrated on Vero cells at high dilutions at which the concentration of EO was not active. The titers, expressed as pfu/ml, are means and SEM for 3 independent experiments performed in duplicate.</p