The aim of this study was to improve the knowledge of phenolic content and antioxidant potential during ripening of different grape varieties (Malvasia, Sercial and Tinta Negra) used to produce Madeira wine. Rapid spectrophotometric methods were selected to obtain this information, since these methods could be used as a routine analytical procedure, being easy, simple, rapid, and cost-effective. A significant correlation was observed between total phenolic content and antioxidant capacity for all grape varieties under study, which suggests that phenolics either alone or in combination are responsible for the grapes antioxidant capacity. Our findings showed significant differences (p < 0.05) for phenolic content and antioxidant capacity for all the studied grape varieties. Sercial grapes showed the highest values of phenolics and antioxidant capacity. Moreover, grape ripening stages revealed a significant impact on grapes phenolic content and antioxidant capacity. This information could be used by viticulturists and winemakers to improve and define Vitis vinifera L. grapes harvest management in order to maximize its bioactive potential.

In recent years, food frauds and adulterations have increased significantly. This practice is motivated by fast economical gains and has an enormous impact on public health, representing an important issue in food science. In this context, this review has been designed to be a useful guide of potential biomarkers of food authenticity and safety. In terms of food authenticity, we focused our attention on biomarkers reported to specify different botanical or geographical origins, genetic diversity or production systems, while at the food safety level, molecular evidences of food adulteration or spoilage will be highlighted. This report is the first to combine results from recent studies in a format that allows a ready overview of metabolites (<1200 Da) and potentially molecular routes to monitor food authentication and safety. This review has therefore the potential to unveil important aspects in food adulteration and safety, contributing to improve the current regulatory frameworks.

MEPS, the acronym of microextraction by packed sorbent, is a simple, fast and user- and environmen tally-friendly miniaturization of the popular solid-phase extraction technique (SPE). In fact, it has been widely shown that MEPS can easily replace SPE for most, if not all, previous applications. It can attain this with obvious gains in sample and solvent usage, which is greatly reduced without compromising the extraction efficiency. Furthermore, MEPS can be operated with semiautomatic electronic syringes, making it very reliable and versatile, particularly to handle very low and very high sample volumes. This review will focus on the strengths and weaknesses of this technique and the different MEPS architectures commer cially available in the context of the MEPS applications reported in the last five years. Additionally, innova tive improvements will be highlighted, particularly those related with new applications and recent MEPS configurations and sorbents, such as the controlled directional flow or the innovative µSPEed variant.

Sotolon is widely associated with the quality of fortified aged wines, and has also been linked to premature oxidative aging (premox). Here we developed a single, fast and environmental-friendly microextraction by packed sorbent ultra-high pressure liquid chromatography analysis (MEPS/UHPLC-PDA) for sotolon quantification in different wines. The best extraction conditions (loading three times 250μL samples through the MEPSPEP sorbent and elution with 100μL of 50% MeOH) were combined with a fast UHPLC separation (5min separation using acidified 10% MeOH isocratic flow in a CORTECS C18 column) to allow unparalleled minimum sample and solvents volumes usage. The validated methodology showed good linearity (r(2)>0.993) and precision (<5.6%); high recovery (>81%) and detection limits (0.45-2.51μg/L) far below sotolon odor threshold for any type of wine. The methodology was successfully applied to selected white table and Madeira wines, encompassing therefore a wide range of alcohol and sugar contents. Furthermore, as far we may know, this is the first time a single methodology can be used to assess both wine aging or premox according to the type of wine.

Introduction Breast cancer (BC) is positioned as the second among all cancers remaining at the top of women´s diseases worldwide followed by colorectum, lung, cervix, and thyroid cancers. The main drawback of most the screening/diagnostic methods is their low sensitivity/specificity and in some cases the invasive procedure required to obtain the samples. Objectives On the present investigation, we report a statistical design was to evaluate by central composite design the influence towards the optimization of the most significant variables of solid-phase microextraction (SPME) procedure for the isolation of volatile organic metabolites (VOMs) from urine of BC patients (N = 31) and healthy individuals (CTL; N = 40). The establishment of the urinary volatomic composition, through gas chromatography-mass spectrometry (GC–MS) analysis, can boost the identification of volatile organic metabolites (VOMs) potential BC biomarkers useful to be used together or to complement the current BC diagnostics tools. Better early detection methods are needed to improve the outcomes of patients with BC. Methods Several combinations of experiments were considered with a central composite design (CCD) of response surface methodology (RSM) for the urinary volatomic pattern. Three-level three-factor CCD was employed assessing the most important extraction-influencing variables—fiber coating, NaCl amount, extraction time and temperature. The optimal conditions were achieved using a carboxen/polydimethylsiloxane fiber with 15% (w/v) NaCl during 75 min at 50 °C. Results A total of ten VOMs belonging to sulfur compounds, terpenoids and carbonyl compounds presented the highest contribution towards discrimination of BC patients from CTL (variable importance in projection (VIP) > 1, p < 0.05). The discrimination efficiency and accuracy of urinary metabolites was ascertained by receiver operating characteristic (ROC) curve analysis that allowed the identification of some metabolites with highest sensitivity and specificity to discriminate the groups. Conclusions The results obtained with this approach suggest the possibility to identify endogenous metabolites as a platform to discovery potential BC biomarkers and paves a way to explore the related metabolomic pathways in order to improve BC diagnostic tools.

his paper reports the effect of storage temperature, storage time and glucose content on furanic derivatives (FDs) formation in fortified Madeira wines using headspace solid phase microextraction (HS–SPME) combined with gas chromatography-quadrupole mass spectrometry (GC–qMS), and microextraction by packed sorbent (MEPS) tandem with ultrahigh pressure liquid chromatography coupled to photodiode array detection (UPLC–PDA). Based on the results obtained, MEPS/UPLC–PDA showed better FDs extraction compared to HS–SPME/GC–qMS, in terms of analysis reduction, sensitivity, reproducibility and allow detect all target furanic derivatives considered in this study. 5-Hydroxymethyl-2-furfural, one of the most abundant FDs in wines, is not detected by HS–SPME/GC–qMS, which suggest that this methodology is not the most suitable to achieve the purpose of this study. Regarding the impact of storage time and temperature on FDs formation using MEPS/UPLC–PDA, it was verified an increase on FDs concentration during storage time independently of storage temperature as well as glucose content, and this increase is also favored by temperature increases, being more significant at 55 °C. The results obtained in this study could be used as a useful tool in winemaking field in order to introduce changes in fermentation as well as baking (estufagem) process, and/or predict the effects of storage time by application of high temperatures.

Background: Food frauds and counterfeit products produced to obtain economic advantages have become a growing concern over the last decade. The assessment of food safety and authenticity constitute a powerful tool to mitigate this problem and protect public health. Nevertheless, the growing sophistication of fraudulent practices requires a continuous update and improvement of the analytical methodologies. Scope and approach: In this context, the advances and novel techniques and chemometric approaches reported since 2016 are discussed regarding their potential use in food authentication. This review details the main analytical techniques applied in the extraction, detection and identification of metabolites to obtain food fingerprints, emphasizing the advantages and drawbacks of each approach with practical examples. Additionally, the current legislation on food authentication has also been revised. Key findings and conclusions: GC-MS, LC- q-TOF-MS and NMR followed by PCA and PLS-DA are the most often reported analytical methodologies to discriminate between authentic and non-authentic foodstuffs using chemical fingerprints. More recently, novel and promising statistical methods with high classification power (DDSIMCA, OO-SIMCA, BPR, k-NN, among others) are being already applied. Overall, the development of nondestructive, on-siteandreal-time analyticalprocedures abletodeliverfastandunambiguous foodauthentication results will continue to be the goal driving food research.

Aroma is a crucial criterion to assess the quality of apple fruits, juices, and ciders. The aim of this study was to explore similarities and differences in volatile profiles among apple fruits, juices, and ciders from different apple varieties (Festa, Branco, and Domingos) by headspace solid-phase microextraction gas chromatography–mass spectroscopy (HS–SPME/GC–MS). A total of 142 volatile organic compounds (VOCs) were identified, but only 9 were common in all analysed matrices and apple-tested varieties. Esters, alcohols, and aldehydes presented a higher concentration in apple fruits and juices, whereas esters, alcohols, and acids were dominant in ciders. Moreover, there were unique VOCs for each matrix and for each variety, highlighting the importance of the selection of apple varieties as an important factor to obtain good sensory and quality ciders, multiple benefits, and legal protection against the misuse of local products.

One of the main food authenticity issues is related to products` false labelling concerning their variety or geo graphical origin. For this reason, the aim of this study was to establish distinctive characteristics for the dis crimination of apple juices according to regional varieties (Rijo, Verde, Ribeiro and Azedo) and geographical origin (Prazeres and Santo da Serra (Madeira Island)) on the basis of their volatile pattern by headspace solid phase microextraction combined with gas chromatography mass spectrometry (HS-SPME/GC–MS) combined with chemometric tools. The results obtained revealed a perfect discrimination between the different apple varieties, with Rijo apple juices as samples with the major relative concentration of ethanol, ethyl butanoate, ethyl 2-methylbutanoate and ethyl hexanoate. Moreover, this study allowed a geographical origin-based clas sification of Azedo apple juices, highlighting ethyl acetate, 2-methyl-1-propanol, ethyl hexanoate, and toluene (described for the first time in apple juices) as discriminatory features. This study demonstrated that volatile organic compounds (VOCs) could serve as authenticity indicators to verify variety and geographical origin of apple juices, providing local producers multiple benefits and legal protection against misuse of the products.

In the current study, a comprehensive approach based on headspace solid-phase microextraction (HS-SPME), combined with gas chromatography-quadrupole mass spectrometry (GC-qMS), was used to establish the volatile signature of fresh and processed fruit juices, obtained from the same batch of grapes, red fruits, orange, pear, and apple. This is a powerful tool for evaluating the impact of the production process on the volatomic pattern of fruit juice. A total of 169 volatile organic compounds (VOCs) belonging to different chemical groups were identified. Esters, carbonyl compounds, terpenoids, and alcohols are the major chemical groups in the investigated fruit juices. However, their contribution to the total volatile profile varied. Special attention should be paid to processed fruit juices to avoid the possible deleterious effects associated with the formation of furanic compounds (e.g., heat treatment), since their furanic content was significantly higher in comparison to that of fresh fruit juices. The knowledge obtained in the current study will allow for the introduction of modifications to the process involved in processing juice, which will improve the organoleptic characteristics of processed juices, contributing to a better acceptance by consumers. Furthermore, more assays should be performed to assess the effect of harvests, geography, and agronomy on the volatile profile of juices.