Abstract:This study describes a non-separative headspace solid phase microextraction-mass spectrometry (HS-SPME-MS) approach, in view of its application to online monitoring of a roasting process. The system can quickly provide representative and diagnostic fingerprints of the volatile fraction of samples and, in combination with appropriate chemometric pattern recognition and regression techniques, can successfully be applied to characterize, discriminate, and/or correlate patterns with the roasting process. Eighty co… Show more
“…Separated peaks were identified using the Wiley NIST MS Library and retention index (RI) values of the compounds were calculated by comparing the retention times of saturated alkanes (C7–C22), which can provide a more accurate identification of the compounds. The RI values were compared to LRI values presented in the literature (Table ) …”
Specific fermentation processes such as digestive bioprocessing and monsooning have been of interest to coffee consumers. Volatile compounds of beans during the different fermentation processes vary considerably and exhibit different profiles. The representative flavor compounds for the luwak green bean were found to be pentamethyl heptane and 3‐methyl‐1‐butanol, while more diverse and distinct compounds were observed from the monsooned green bean, namely alkyl butanals, pinenes, benzaldehyde and butanediols. However, after roasting, the fermented form of both beans contained similar types of volatiles and their relative contents compared to those of non‐fermented roasted beans, except for α‐pinene in luwak and 2‐methyl furan in monsooned beans. In principal components analysis and partial least squares‐discriminant analysis (PLS‐DA), the different fermented beans were clearly distinguished by the extracted peak entities from their total ion chromatograms. The s‐plot and variable importance on projection (VIP) values related to PLS‐DA showed the significant compounds contributing to the identification of the groups. 3‐Methyl‐1‐butanol was the most distinctive compound for the luwak green bean, and β‐pinene, ethylbenzene and benzaldehyde were found to be the significant compounds in the monsooned green bean. In roasted beans, the most significant compounds to distinguish luwak were furfural, α‐pinene and 3‐carene with high variable in the projection (VIP) values. A significant presence of pyrazine, alkyl pyrazines, pyridine and alkyl pyridines contributed to differentiating both fermented roasted coffee beans from the unfermented roasted beans.
“…Separated peaks were identified using the Wiley NIST MS Library and retention index (RI) values of the compounds were calculated by comparing the retention times of saturated alkanes (C7–C22), which can provide a more accurate identification of the compounds. The RI values were compared to LRI values presented in the literature (Table ) …”
Specific fermentation processes such as digestive bioprocessing and monsooning have been of interest to coffee consumers. Volatile compounds of beans during the different fermentation processes vary considerably and exhibit different profiles. The representative flavor compounds for the luwak green bean were found to be pentamethyl heptane and 3‐methyl‐1‐butanol, while more diverse and distinct compounds were observed from the monsooned green bean, namely alkyl butanals, pinenes, benzaldehyde and butanediols. However, after roasting, the fermented form of both beans contained similar types of volatiles and their relative contents compared to those of non‐fermented roasted beans, except for α‐pinene in luwak and 2‐methyl furan in monsooned beans. In principal components analysis and partial least squares‐discriminant analysis (PLS‐DA), the different fermented beans were clearly distinguished by the extracted peak entities from their total ion chromatograms. The s‐plot and variable importance on projection (VIP) values related to PLS‐DA showed the significant compounds contributing to the identification of the groups. 3‐Methyl‐1‐butanol was the most distinctive compound for the luwak green bean, and β‐pinene, ethylbenzene and benzaldehyde were found to be the significant compounds in the monsooned green bean. In roasted beans, the most significant compounds to distinguish luwak were furfural, α‐pinene and 3‐carene with high variable in the projection (VIP) values. A significant presence of pyrazine, alkyl pyrazines, pyridine and alkyl pyridines contributed to differentiating both fermented roasted coffee beans from the unfermented roasted beans.
“…SPME allows for solvent minimization and provides for higher sample enrichment. Different forms of SPME techniques are practiced, but the headspace type (HS-SPME) is very suitable in the analysis of volatile compounds [121, 122]. Affinity of an analyte towards the fiber can be enhanced by carefully selecting the right polymer coating material [123].…”
Section: Extraction Methods For Bioactive Micronutrients Of Coffeementioning
Production of coffee beans is an important lifeline for the economy of several countries in Latin America, Africa, and Asia. The brew from this well sought for cash crop is readily consumed due to its good sensory qualities owing to the presence of many micronutrients. Some of these chemical compounds possess biological activities, including antiproliferative, antioxidant, and antimicrobial effects. Four representative groups of these micronutrients, namely, caffeine, chlorogenic acid, diterpenes, and trigonelline, play key roles in these bioactive effects of coffee. In order to guarantee the quality of coffee products and to protect consumer interest and safeguard their well-being, it is extremely important to employ sensitive and accurate analytical methods in the characterization and quantitative determination of these bioactive constituents. This review aims to present recent applications in this regard.
“…These MS-based nose results detailed the volatile-profile differentiations and provided an important chemical markers in a form of discriminative MS dataset as “digital fingerprints” for dogfruit and stink bean during maturity for further development of rapid measurement technology on volatile alterations evaluation of these legumes or their derivative products [21] . The MS-based electronic nose method and chemometric data analysis might thus be applied for monitoring the flavor quality of smelly plant materials in a faster and thorough manner than compositional GC measurement, which confirms the advantageous use of MS-based e-nose profiling technique on differentiation of food flavor [19] , [20] , [21] , [31] , [32] . Fig.…”
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
