Differentiation of the Organoleptic Volatile Organic Compound Profile of Three Edible Seaweeds

Funding Information: This research was funded by FUNDAÇÃO PARA A CIÊNCIA E TECNOLOGIA (FCT—PORTUGAL), grant number PD/BDE/150627/2020. This research was funded by MAR2020 – PORTUGUESE GOVERNMENT, project number MAR-01.03.0-FEAMP-0016. Funding Information: P.C.M. acknowledges Fundação para a Ciência e Tecnologia (FCT—Portugal) for his doctoral grant (PD/BDE/150627/2020). Publisher Copyright: © 2023 by the authors.The inclusion of seaweeds in daily-consumption food is a worthy-of-attention challenge due to their high nutritional value and potential health benefits. In this way, their composition, organoleptic profile, and toxicity must be assessed. This work focuses on studying the volatile organic compounds (VOCs) emitted by three edible seaweeds, Grateloupia turuturu, Codium tomentosum, and Bifurcaria bifurcata, with the aim of deepening the knowledge regarding their organoleptic profiles. Nine samples of each seaweed were prepared in glass vials, and the emitted headspace was analyzed, for the first time, with a gas chromatography—ion mobility spectrometry device, a highly sensitive technology. By statistically processing the collected data through PCA, it was possible to accurately differentiate the characteristic patterns of the three seaweeds with a total explained variance of 98%. If the data were pre-processed through PLS Regression, the total explained variance increased to 99.36%. The identification of 13 VOCs was accomplished through a developed database of compounds. These outstanding values in addition to the identification of the main emissions of VOCs and the utilization of a never-before-used technology prove the capacity of GC-IMS to differentiate edible seaweeds based solely on their volatile emissions, increase the knowledge regarding their organoleptic profiles, and provide an important step forward in the inclusion of these highly nutritional ingredients in the human diet.publishersversionpublishe

Urinarv volatiles and chemical characterisation for the non-invasive detection of prostate and bladder cancers

Bladder cancer (BCa) and prostate cancer (PCa) are some of the most common cancers in the world. In both BCa and PCa, the diagnosis is often confirmed with an invasive technique that carries a risk to the patient. Consequently, a non-invasive diagnostic approach would be medically desirable and beneficial to the patient. The use of volatile organic compounds (VOCs) for disease diagnosis, including cancer, is a promising research area that could support the diagnosis process. In this study, we investigated the urinary VOC profiles in BCa, PCa patients and non-cancerous controls by using gas chromatography-ion mobility spectrometry (GC-IMS) and gas chromatography time-of-flight mass spectrometry (GC-TOF-MS) to analyse patient samples. GC-IMS separated BCa from PCa (area under the curve: AUC: 0.97 (0.93–1.00)), BCa vs. non-cancerous (AUC: 0.95 (0.90–0.99)) and PCa vs. non-cancerous (AUC: 0.89 (0.83–0.94)) whereas GC-TOF-MS differentiated BCa from PCa (AUC: 0.84 (0.73–0.93)), BCa vs. non-cancerous (AUC: 0.81 (0.70–0.90)) and PCa vs. non-cancerous (AUC: 0.94 (0.90–0.97)). According to our study, a total of 34 biomarkers were found using GC-TOF-MS data, of which 13 VOCs were associated with BCa, seven were associated with PCa, and 14 VOCs were found in the comparison of BCa and PCa

Biomarkers Used for the Diagnosis of Diseases

The detection and quantification of with high precision nucleic acid biomarkers and protein biomarkers in resource-limited settings is key to the early diagnosis of diseases and for monitoring the effects of treatments. As there is an enormous demand for high-quality biomarker detection platforms that are robust and highly applicable in resource-limited settings, this book is devoted to exploring methods for detection and quantification of biomarkers, focusing on the recent advances in this field

Gas phase biomarkers for disease diagnostics by ion-mobility

The detection of Volatile Organic Compounds (VOCs) has shown great potential as a noninvasive and rapid diagnostic tool for early cancer and disease detection. The use of VOCs for early disease detection has several advantages and can provide valuable insights into disease pathophysiology. This PhD research aimed to investigate the presence of VOCs in urine samples and the development of chemical fingerprints for various cancers, namely, bladder cancer, colorectal cancer, prostate cancer and hepatocellular cancer, and diseases such as fibrosis and urinary tract infection. This study investigated the possibility of using analytical techniques such as Gas Chromatography-Ion Mobility Spectrometry (GC-IMS), Gas Chromatography-Time of Flight-Mass Spectrometry (GC-TOF-MS), and Electronic Noses (eNoses) for the identification of these biomarkers. The study findings demonstrate the presence of particular VOCs in urine samples. We found that GC-IMS and GC-TOF-MS was able to distinguish between some of the cancers with 100% sensitivity and 100% specificity. During this research, a total of 46 VOCs were identified as relevant for the identification of these cancer groups, with some VOCs being specific to each type of cancer. 13 VOCs with the highest concentration in urine samples of bladder cancer patients were identified in the course of this study. The electronic noses utilized in this research were the AlphaMOS FOX 4000 and PEN3 eNose. The AlphaMOS FOX 4000 was able to distinguish between some of the cancer groups with 100% sensitivity and 100% specificity. Although, PEN3 eNose did not exhibit 100% sensitivity in distinguishing between the different cancer groups, it still demonstrated high levels of sensitivity and specificity. Overall, the study contributes to the advancement of research on the detection of VOCs and provides insights into the potential for using analytical techniques for the detection of VOCs in urine samples. However, there are some limitations to these technologies such as some of them require specialized training and expertise to operate and interpret results accurately and the cost of some of these technologies can be high, making them less accessible. Another limitation is that the detection of VOCs can be affected by factors such as sample collection, handling, and storage, which can impact on the accuracy of results. The second aim of this research presents the development of an in-house device based on Photo Ionisation Detector (PID) for the detection of VOCs. The thesis focuses on the xxii evaluation of the performance of the developed PID+ based device for detecting ISB. Throughout this thesis, we have examined the electronics of PID+. Experiments were conducted to assess the performance of the PID+ at various flow rates, ISB (Isobutylene) gas concentrations, bias voltages of detector plates, and amplifier circuit gains. The results of the study demonstrate the feasibility and efficacy of the developed device in detecting ISB with high response. It was observed that increasing the flow rate of the sample gas has the potential to improve the response time of the detector. Additionally, it was observed that the concentration of the target VOCs, in this case ISB gas, was a crucial factor that affected the response of the detector, with higher concentrations resulting in higher sensitivities. However, it was noted that elevating either the flow rate or the concentration of the target VOCs beyond a certain threshold could lead to the saturation of the output. During the testing of the two versions of PID+, the performance of the PID+ was significantly improved. Nevertheless, more extensive research is required to verify the validity of the results of this study with respect to various VOCs