Development and optimization of a HS-SPME-GC-MS methodology to quantify volatile carbonyl compounds in Port wines

Development of a fiber derivatization method for the analysis of 18 carbonyl compounds in roasted lamb using HS-SPME/GC-TQ/MS

A method based on headspace solid-phase microextraction fiber derivatization (HS-SPME-FD) coupled with gas chromatography-triple quadrupole mass spectrometry (GC-TQ/MS) was developed to quantify 18 flavor-related carbonyl compounds in roasted lamb. Optimization of derivatization conditions established the following optimal parameters: a 3 g/L concentration of O-2,3,4,5,6-(pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA), fiber loading at 50 °C for 5 min, followed by simultaneous extraction/derivatization at 50 °C for 30 min. The method was validated for linearity, limits of detection (LOD), limits of quantification (LOQ), precision, and accuracy. Results confirmed the method's suitability for determining carbonyl compounds in roasted lamb. During roasting, the composition and concentration of carbonyl compounds increased significantly, with hexanal being the most abundant. Additionally, the method detected carbonyl compounds in the model system at levels comparable to real roasted lamb, validating both the model's accuracy and the method's quantitative precision.

Discrimination and characterization of the volatile organic compounds in red and black raspberry wines fermented with different commercial Saccharomyces cerevisiae: An integrated analysis using E-nose, GC-MS, GC-IMS, and multivariate statistical models

This study employed E-nose, GC-MS, and GC-IMS to analyze the volatile organic compounds (VOCs) of red and black raspberry wines fermented by commercial Saccharomyces cerevisiae (X16, RB2, XarOm). Relative odor activity value (ROAV) analysis, orthogonal partial least squares discriminant analysis (OPLS-DA), and random forest (RF) were employed to assess the VOCs and predict key aroma compounds comprehensively. The results revealed that red raspberry wine has a higher ester content (64.18% of total VOC content), while black raspberry wine showcased a significantly higher terpene concentration (13.60%). Moreover, the raspberry wine fermented with X16 yeasts demonstrated the highest contents of esters (64.88%) and alcohols (26.21%). In contrast, the RB2 yeasts displayed a higher level of terpenes (9.56%). The ROAV analysis, OPLS-DA, and RF models predicted 11 key aroma compounds in samples. These findings would provide valuable data for the application of commercial S. cerevisiae in the flavor modulation of raspberry wine.

Characterization of volatile profile from different coriander (Coriandrum sativum L.) varieties via HS-SPME/GC-MS combined with E-nose analyzed by chemometrics

Headspace-solid phase microextraction/gas chromatography-mass spectrometry (HS-SPME/GC-MS) and electronic nose (E-nose) technologies were implemented to characterize the volatile profile of aerial part from 40 coriander varieties. A total of 207 volatile compounds were identified and quantified, including aldehydes, alcohols, terpenes, hydrocarbons, esters, ketones, acids, furans, phenols and others. E-nose results showed that W5S and W2W were representative sensors responding to coriander odor. Among all varieties, the number (21-30 species) and content (449.94-1050.55 μg/g) of aldehydes were the highest, and the most abundant analytes were (Z)-9-hexadecenal or (E)-2-tetratecenal, which accounted for approximately one-third of the total content. In addition, 37 components were determined the characteristic constituents with odor activity values (OAVs) ≥ 1, mainly presenting citrusy, fatty, soapy and floral smells. Hierarchical cluster analysis (HCA) and principal component analysis (PCA) could effectively distinguish different varieties. This study provided a crucial theoretical basis for flavor evaluation and quality improvement of coriander germplasm resources.

Aroma determination in alcoholic beverages: Green MS-based sample preparation approaches

Aroma determination in alcoholic beverages has become a hot research topic due to the ongoing effort to obtain quality products, especially in a globalized market. Consumer satisfaction is mainly achieved by balancing several aroma compounds, which are mixtures of numerous volatile molecules enclosed in challenging matrices. Thus, sample preparation strategies for quality control and product development are required. They involve several steps including copious amounts of hazardous solvents or time-consuming procedures. This is bucking the trend of the ever-increasing pressure to reduce the environmental impact of analytical chemistry processes. Hence, the evolution of sample preparation procedures has directed towards miniaturized techniques to decrease or avoid the use of hazardous solvents and integrating sampling, extraction, and enrichment of the targeted analytes in fewer steps. Mass spectrometry coupled to gas or liquid chromatography is particularly well suited to address the complexity of these matrices. This review surveys advancements of green miniaturized techniques coupled to mass spectrometry applied on all categories of odor-active molecules in the most consumed alcoholic beverages: beer, wine, and spirits. The targeted literature consider progresses over the past 20 years.

Room-Temperature Sensing Mechanism of GQDs/BiSbO4 Nanorod Clusters: Experimental and Density Functional Theory Study

Creating high-performance gas sensors for heptanal detection at room temperature demands the development of sensing materials that incorporate distinct spatial configurations, functional components, and active surfaces. In this study, we employed a straightforward method combining hydrothermal strategy with ultrasonic processing to produce mesoporous graphene quantum dots/bismuth antimonate (GQDs/BiSbO4) with nanorod cluster forms. The BiSbO4 was incorporated with appropriate contents of GQDs resulting in significantly improved attributes such as heightened sensitivity (59.6@30 ppm), a lower threshold for detection (356 ppb), and quicker period for response (40 s). A synergistic mechanism that leverages the inherent advantages of BiSbO4 was proposed, while its distinctive mesoporous hollow cubic structure, the presence of oxygen vacancies, and the catalytic enhancement provided by GQDs lead to a marked improvement in heptanal detection. This work introduces a straightforward and effective method for crafting sophisticated micro-nanostructures that optimize spatial design, functionality, and active mesoporous surfaces, showing great promise for heptanal sensing applications.

Green infant formula analysis: Optimizing headspace solid-phase microextraction of carbonyl compounds associated with lipid peroxidation using GC-MS and pentafluorophenylhydrazine derivatization

The refinement and optimization of a method combining headspace solid-phase microextraction (HS-SPME) with gas chromatography-mass spectrometry (GC-MS) was successfully performed for the first time to determine seven carbonyl and dicarbonyl compounds, including glyoxal, methylglyoxal, dimethylglyoxal, and malondialdehyde in infant formulae, related to lipid peroxidation. HS-SPME was utilized for simultaneous extraction and derivatization with pentafluorophenylhydrazine (PFPH). Critical parameters such as temperature, pH, extractive phase, and salting-out were meticulously investigated and fine-tuned by an asymmetrical 2232//9 screening design to ensure the method's efficacy and reliability. Optimal conditions included a PFPH concentration of 5 g/L, pH 5.0, head-space extraction at 60 °C within 10 min, utilizing a DVB/CAR/PDMS coating, and a 20% w/w salting-out. The analytical validation of this method, compliant with FDA guidelines, demonstrated exceptional linearity, sensitivity, specificity, precision (RSD ≤13.8%), and accuracy (84.8% ≤ recovery ≤111.5%). The metric approach AGREEprep confirms its eco-friendliness, marking a significant step towards an environmentally conscious approach in infant formula analysis. An occurrence study conducted on 25 infant formula samples revealed widespread carbonyl and dicarbonyl compounds in both powdered and liquid variants. ANOVA results exhibited variations in compound concentrations among different sample groups. Clustering analyses delineated distinct groups based on carbonyl content, indicating the potential of these compounds as markers for lipid peroxidation and food quality assessment. This method serves as a valuable tool for evaluating infant formula quality, stability towards oxidation, and safety.

Comparative Analysis of Nutritional Quality, Serum Biochemical Indices, and Visceral Peritoneum of Grass Carp (Ctenopharyngodon idellus) Fed with Two Distinct Aquaculture Systems

This study scrutinized the nutritional quality and serum biochemical indices of grass carp (Ctenopharyngodon idellus) cultivated in traditional pond intercropping (TPI) and in-pond raceway system (IPRS) aquaculture setups. The findings showed that the TPI group exhibited a superior water-holding capacity, while the IPRS showcased heightened crude lipid content and levels of textural properties such as springiness. Moreover, significant differences emerged in the fatty acid profiles, with the TPI group manifesting higher total polyunsaturated fatty acids (ΣPUFAs), EPA, DHA, and Σn-3, while the IPRS group exhibited elevated total saturated fatty acids (ΣSFAs). In terms of amino acids, valine and histidine levels were notably higher in the IPRS group, whereas lysine levels were reduced. Volatile compound analysis revealed significant variations, with the IPRS group containing more volatile substances with a better aroma, resulting in a better odor. The IPRS group performed better in serum biochemistry analysis. Additionally, grass carp in the IPRS group displayed an improved structure and greater coverage area of the visceral peritoneum, appearing lighter in color compared to the TPI group. TPI mainly influences nutritional elements; IPRSs primarily affect muscle texture, serum biochemistry, and overall health. This study aims to fill the gap in quality comparison research and provide an important scientific basis.

Development of a Fully Automated Method HS-SPME-GC-MS/MS for the Determination of Odor-Active Carbonyls in Wines: a "Green" Approach to Improve Robustness and Productivity in the Oenological Analytical Chemistry

The aim of this study was the optimization and validation of a green, robust, and comprehensive method for the determination of volatile carbonyl compounds (VCCs) in wines that could be added as a new quality control tool for the evaluation of a complete fermentation, correct winemaking style, and proper bottling and storage. A HS-SPME-GC-MS/MS method was optimized and automated using the autosampler to improve overall performance. A solvent-less technique and a strong minimization of all volumes were implemented to comply with the green analytical chemistry principles. There were as many as 44 VCC (mainly linear aldehydes, Strecker aldehydes, unsaturated aldehydes, ketones, and many other) analytes under investigation. All compounds showed a good linearity, and the LOQs were abundantly under the relevant perception thresholds. Intraday, 5-day interday repeatability, and recovery performances in a spiked real sample were evaluated showing satisfactory results. The method was applied to determine the evolution of VCCs in white and red wines after accelerated aging for 5 weeks at 50 °C. Furans and linear and Strecker aldehydes were the compounds that showed the most important variation; many VCCs increased in both classes of samples, whereas some showed different behaviors between white and red cultivars. The obtained results are in strong accordance with the latest models on carbonyl evolution related to wine aging.

Headspace Microextraction. A Comprehensive Review on Method Application to the Analysis of Real Samples (from 2018 till Present)

This work describes current trends in the development of headspace microextraction methods. The main trends in the selection of detection techniques used in combination with microextraction and preferences in the selection of headspace liquid-phase microextraction (HS-LPME) or headspace solid-phase microextraction (HS-SPME) methods, depending on the analytes and their quantity, are also briefly presented. In the main part of the work, on the basis of current journal literature, headspace microextraction analytical methods used for the determination of various inorganic and organic analytes are classified and compared over the last five years. The work also reflects the current modifications of techniques and approaches proposed for these microextraction methods.

Selected Maillard Reaction Products and Their Yeast Metabolites in Commercial Wines

During beer and wine production, Maillard reaction products (MRPs) are formed, which have a particular influence on the taste and aroma of the fermented beverages. Compared to beer, less is known about individual Maillard compounds and especially corresponding yeast metabolites in wine. In this study, 36 selected wines (Amarone, Ripasso, red, and white wines) were analyzed by HPLC-UV and GC-MS concerning the amounts of 3-deoxyglucosone (3-DG), 3-deoxygalactosone (3-DGal), methylglyoxal (MGO), glyoxal (GO), 5-hydroxymethylfurfural (HMF), and furfural (FF). 3-DG was found to be the dominant compound with values from 3.3 to 35.1 mg/L. The contents of 3-DGal, MGO, GO, HMF, and FF were in a single digit range. In addition to MRPs, the yeast metabolites originating from 3-DG, namely, 3-deoxyfructose and 3-deoxy-2-ketogluconic acid, 2,5-bis(hydroxymethyl)furan and 5-formyl-2-furancarboxylic acid, both formed from HMF, and the FF metabolites furfuryl alcohol and furan-2-carboxylic acid were detected and quantitated in wines for the first time. The amounts were between 0.1 and 53.5 mg/L with especially high contents of the oxidation products. Differences between red and white wines indicate that enological parameters like grape variety, production method, and aging may have an influence on the MRP contents in wines.

Typical Aroma of Merlot Dry Red Wine from Eastern Foothill of Helan Mountain in Ningxia, China

Aroma is an important aspect of wine quality and consumer appreciation. The volatile organic compounds (VOCs) and olfactory profiles of Merlot dry red wines from the Eastern Foothill of Helan Mountain (EFHM) were analyzed using gas chromatography-mass spectrometry and quantitative descriptive analysis. The results showed that Merlot wines from EFHM were characterized by intense flavors of drupe and tropical fruits compared with the Gansu region. Nineteen VOCs were defined as essential compounds contributing to the aroma characteristics of the Merlot wines through gas chromatography-olfactometry/mass spectrometry and odor activity value analysis. Predominantly, geranyl isovalerate, which contributed to the herbal odors of the Merlot wines, was detected in the grape wine of EFHM for the first time. The addition experiment revealed that geranyl isovalerate influenced the aroma quality of wine by increasing herbal odors and enhancing the olfactory intensities of tropical fruits. These results are helpful for further understanding the aroma of Merlot wines from EFHM and improving the quality of wine aromas.

A New Perspective on SPME and SPME Arrow: Formaldehyde Determination by On-Sample Derivatization Coupled with Multiple and Cooling-Assisted Extractions

Formaldehyde (FA) is a toxic compound and a human carcinogen. Regulating FA-releasing substances in commercial goods is a growing and interesting topic: worldwide production sectors, like food industries, textiles, wood manufacture, and cosmetics, are involved. Thus, there is a need for sensitive, economical, and specific FA monitoring tools. Solid-phase microextraction (SPME), with O-(2,3,4,5,6-pentafluorobenzyl)-hydroxylamine (PFBHA) on-sample derivatization and gas chromatography, is proposed for FA monitoring of real-life samples. This study reports the use of polydimethylsiloxane (PDMS) as a sorbent phase combined with innovative commercial methods, such as multiple SPME (MSPME) and cooling-assisted SPME, for FA determination. Critical steps, such as extraction and sampling, were evaluated in method development. The derivatization was performed at 60 °C for 30 min, followed by 15 min sampling at 10 °C, in three cycles (SPME Arrow) or six cycles (SPME). The sensitivity was satisfactory for the method's purposes (LOD-LOQ at 11-36 ng L^-1, and 8-26 ng L^-1, for SPME and SPME Arrow, respectively). The method's linearity ranges from the lower LOQ at trace level (ng L^-1) to the upper LOQ at 40 mg L^-1. The precision range was 5.7-10.2% and 4.8-9.6% and the accuracy was 97.4% and 96.3% for SPME and SPME Arrow, respectively. The cooling MSPME set-up applied to real commercial goods provided results of quality comparable to previously published data.

Comparative study on nutritional quality and serum biochemical indices of common carp (Cyprinus carpio) aged 11 to 13 months aged cultured in traditional ponds and land-based container aquaculture systems

In the study, the physical characteristics, nutritional composition, mineral elements, volatile substances, and serum biochemistry of common carp (Cyprinus carpio) after rearing for two months were compared and analyzed to reveal the differences in muscle nutritional quality and serum biochemical indices between fish raised in traditional ponds (TP) and land-based container recirculating aquaculture systems (C-RAS). One hundred fish were selected from each aquaculture mode for the following experiments. Results show that: in terms of physical properties, C-RAS frozen seepage rate was significantly lower than that in TP (P < 0.05), the chewiness, gumminess, springiness, resilience, adhesiveness, cohesiveness, and shearing of C-RAS group were significantly higher than in TP (P < 0.01). Regarding muscle nutrients, the moisture, the crude lipid contents of C-RAS group were significantly lower than that of the TP group (P < 0.05), and the crude protein content of C-RAS group was extremely significantly higher than that in TP (P < 0.01). The saturated fatty acids (ΣSFA) and polyunsaturated fatty acids (ΣPUFA) in the muscle of C-RAS were significantly higher than that in TP (P < 0.01), and monounsaturated fatty acids (ΣMUFA) of C-RAS were significantly lower than that in TP (P < 0.01). Methionine content in C-RAS was significantly higher than that in TP (P < 0.05). In terms of mineral elements, the contents of K and Se in C-RAS were significantly higher than those in TP, and the content of Zn in C-RAS was significantly lower than that in TP (P < 0.05). In terms of volatile substances, nonanal, octanal, and benzaldehyde in C-RAS were significantly lower than those in TP(P < 0.01), 2,3-diethyl-5-methylpyrazine, ethyl 3-methylpentanoate, butyl formate were significantly higher than those in TP (P < 0.01). In terms of serum biochemistry, the glucose index in C-RAS was extremely significantly lower than that in TP group, total protein, albumin, alkaline phosphatase, and triglyceride were extremely significantly higher than those in TP (P < 0.01). Experiments show that the aquaculture mode has a large impact on the physical properties of the common carp, nutrients, mineral elements, volatile matter, and serum biochemical. In conclusion, the common carp cultured in C-RAS systems had better muscle nutritional quality, which provides a reference for future regulation of fish nutritional quality by C-RAS.

Volatile Composition of Fortification Grape Spirit and Port Wine: Where Do We Stand?

Port wine's prominence worldwide is unequivocal and the grape spirit, which comprises roughly one fifth of the total volume of this fortified wine, is also a contributor to the recognized quality of this beverage. Nonetheless, information about the influence of the grape spirit on the final aroma of Port wine, as well as its volatile composition, is extremely limited. Moreover, the aroma characteristics of Port wines are modulated mainly by their volatile profiles. Hence, this review presents a detailed overview of the volatile composition of the fortification spirit and Port wine, along with the methodologies employed for their characterization. Moreover, it gives a general overview of the Douro Demarcated Region (Portugal) and the relevance of fortification spirit to the production of Port wine. As far as we know, this review contains the most extensive database on the volatile composition of grape spirit and Port wine, corresponding to 23 and 208 compounds, respectively. To conclude, the global outlook and future challenges are addressed, with the position of the analytical coverage of the chemical data on volatile components discussed as crucial for the innovation centered on consumer preferences.

Tracing the Volatilomic Fingerprint of the Most Popular Italian Fortified Wines

The aim of the current study was to provide a useful platform to identify characteristic molecular markers related to the authenticity of Italian fortified wines. For this purpose, the volatilomic fingerprint of the most popular Italian fortified wines was established using headspace solid-phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME/GC-MS). Several volatile organic compounds (VOCs), belonging with distinct chemical groups, were identified, ten of which are common to all the analyzed fortified Italian wines. Terpenoids were the most abundant chemical group in Campari bitter wines due to limonene's high contribution to the total volatilomic fingerprint, whereas for Marsala wines, alcohols and esters were the most predominant chemical groups. The fortified Italian wines VOCs network demonstrated that the furanic compounds 2-furfural, ethyl furoate, and 5-methyl-2-furfural, constitute potential molecular markers of Marsala wines, while the terpenoids nerol, α-terpeniol, limonene, and menthone isomers, are characteristic of Vermouth wines. In addition, butanediol was detected only in Barolo wines, and β-phellandrene and β-myrcene only in Campari wines. The obtained data reveal an adequate tool to establish the authenticity and genuineness of Italian fortified wines, and at the same time constitute a valuable contribution to identify potential cases of fraud or adulteration to which they are subject, due to the high commercial value associated with these wines. In addition, they contribute to the deepening of scientific knowledge that supports its valorization and guarantee of quality and safety for consumers.

Differentiating Huangjiu with Varying Sugar Contents from Different Regions Based on Targeted Metabolomics Analyses of Volatile Carbonyl Compounds

Huangjiu is one of the oldest alcoholic beverages in the world. It is usually made by fermenting grains, and Qu is used as a saccharifying and fermenting agent. In this study, we identified differential carbonyl compounds in Huangjiu with varying sugar contents from different regions. First, we developed and validated a detection method for volatile carbonyl compounds in Huangjiu, and for optimal extraction, 5 mL of Huangjiu and 1.3 g/L of O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA) were incubated at 45 °C for 5 min before extracting the volatile carbonyl compounds at 45 °C for 35 min. Second, the targeted quantitative analysis of 50 carbonyl compounds in Huangjiu showed high levels of Strecker aldehydes and furans. Finally, orthogonal projections to latent structures discriminant analysis (OPLS-DA) was used to differentiate between Huangjiu with different sugar contents, raw materials, and region of origin. A total of 19 differential carbonyl compounds (VIP > 1, p < 0.05) were found in Huangjiu with different sugar contents (semidry and semisweet Huangjiu), and 20 differential carbonyl compounds (VIP > 1, p < 0.05) were found in different raw materials for Huangjiu production (rice and nonrice Huangjiu). A total of twenty-two and eight differential carbonyl compounds, with VIP > 1 and p < 0.05, were identified in semidry and semisweet Huangjiu from different regions (Zhejiang, Jiangsu, Shanghai, and Fujian), respectively.

A novel UHPLC-MS/MS method for the determination of four α-dicarbonyl compounds in wine and dynamic monitoring in human urine after drinking

α-dicarbonyl compounds (α-DCs) serve as potential biomarkers for oxidative stress-related diseases but are difficult to detect.To study the metabolism of carbonyl compounds, we developed a new mass spectrometry probe, 3-benzyl-2-oxo-4λ³-thiazolidine-4-carbohydrazide (BOTC), containing hydrazyl groups for the targeted detection of carbonyl functional groups.In a novel approach, we used BOTC pre-column derivatization with ultrahigh performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) to simultaneously detect four kinds of α-DCs in red wine as well as in urine after drinking. The α-DCs were completely separated (R² ≥ 0.9995), detection was sensitive (detection limit was 12.5-50 fmol), consistent (intraday and interday precision was 0.1-5.7 %), and efficient (average recoveries were 103.3-110.2 %). The method was applied to the analysis of α-DCs in different wines and the dynamic monitoring of transit and excretion in vivo after drinking. Our novel method provides a new strategy for the detection of α-dicarbonyl compounds in red wine and dicarbonyl compounds produced in oxidative stress-related diseases.

Derivatization Strategies in Flavor Analysis: An Overview over the Wine and Beer Scenario

Wine and beer are the most appreciated and consumed beverages in the world. This success is mainly due to their characteristic taste, smell, and aroma, which can delight consumer’s palates. These olfactory characteristics are produced from specific classes of volatile compounds called “volatile odor-active compounds” linked to different factors such as age and production. Given the vast market of drinking beverages, the characterization of these odor compounds is increasingly important. However, the chemical complexity of these beverages has led the scientific community to develop several analytical techniques for extracting and quantifying these molecules. Even though the recent “green-oriented” trend is directed towards direct preparation-free procedures, for some class of analytes a conventional step like derivatization is unavoidable. This review is a snapshot of the most used derivatization strategies developed in the last 15 years for VOAs’ determination in wine and beer, the most consumed fermented beverages worldwide and among the most complex ones. A comprehensive overview is provided for every method, whereas pros and cons are critically analyzed and discussed. Emphasis was given to miniaturized methods which are more consistent with the principles of “green analytical chemistry”.

The Impact of Storage Conditions and Bottle Orientation on the Evolution of Phenolic and Volatile Compounds of Vintage Port Wine

This work evaluates the influence of the cellar conditions and bottle orientation, on the phenolic and volatile composition of a Vintage Port wine, sealed with natural cork stoppers, for 44 months post-bottling. The storage was performed in two different cellars, namely a cellar A with controlled temperature and humidity, and a cellar B, representing a traditional cellar, with uncontrolled temperature and humidity. The impact of bottle orientation was studied in cellar A, where the bottles were stored in horizontal and vertical positions. The phenolic and volatile composition of the bottled Vintage Port wine were analyzed after 6, 15 and 44 months. The results unveiled that the cellar conditions and bottle orientation had an impact in Port wine composition which was higher at 44 months post-bottling. The samples stored in the traditional cellar unveiled significantly higher yellow tones, lower tannin specific activity, and higher levels of furfural and 5-methylfurfural. Furthermore, the samples stored in the horizontal position revealed significant higher levels of total proanthocyanidins and higher tannin specific activity than the samples stored in the vertical position. Interestingly, for the first time to our knowledge, an ellagitannin-derived compound (Corklin) was detected in Vintage Port wines stored in the horizontal position, which results from the reaction of cork constituents with phenolic compounds present in wines.

Valorization of Traditional Alcoholic Beverages: The Study of the Sicilian Amarena Wine during Bottle Aging

Traditional alcoholic beverages have always been part of the Mediterranean culture and, lately, they have been re-evaluated to valorize both the territory and local customs. In this study, the Amarena wine, a fortified wine included in the national list of the traditional agri-food products, was characterized during bottle aging for oenological parameters, chromaticity, volatiles, and inorganic elements. Then, experimental data were visually interpreted by a principal component analysis (PCA). PCA revealed that most of oenological parameters (i.e., alcoholic grade, total dry extract, sugars, organic acids, and phenolic compounds) had a scarce discriminating power. Additionally, ethyl esters were only present in younger products, while remaining at quite constant levels. Conversely, certain metals (i.e., Mg, Na, Mn, Zn, and Cu), chromatic properties, and pH differentiated older Amarena bottles from the younger counterpart. Particularly, acetaldehyde and furanic compounds proved to be valid aging markers. A sensorial analysis highlighted that fruity and floral odors and flavors characterized younger beverages, while dried fruity, nutty, and spicy notes were displayed by older products, along with the valuable attribute of “oxidized” typically observed in aged Sherry wines. Overall, this study may encourage the production and commercialization of the Amarena wine, thus preserving the cultural heritage of the Mediterranean area.

Key aroma compounds of Canastra cheese: HS-SPME optimization assisted by olfactometry and chemometrics

An analytical method was developed to determine volatile compounds (VC) that contribute to the aroma of cheese from Serra da Canastra (Brazil) and evaluate them in three ripening stages (fresh, short-ripened, and ripened) via headspace solid-phase microextraction (HS-SPME) combined with gas chromatography (GC). Proximate and fatty acid compositions were determined to observe whether there would be changes during ripening. Multivariate designs were applied to optimize the extraction parameters of volatile compounds and assisted by GC olfactometry (GC-O) and chemometrics. The adopted strategy revealed that the best extraction condition requires 10 min of equilibration, 75.2 min of fiber exposure at 40 °C, and 1 g of sample. The data obtained evidenced the alteration of the abundance of volatile compounds, fatty acids, and proximate composition of Canastra cheese during ripening. The fatty acid profile of the samples was mainly composed of palmitic, oleic, and stearic acids. This dairy product is rich in volatile compounds and formed primarily by alcohols (n = 14), acids (n = 13), and esters (n = 11). Olfactometry indicated that the VCs that most affected the aroma of ripened Canastra cheese were acetic acid, isobutyric acid, butanoic acid, and ethyl hexanoate. The method developed effectively discriminated against Canastra cheeses at their different ripening stages.

Combination of solid phase microextraction and low energy electron ionisation gas chromatography-quadrupole time-of-flight mass spectrometry to meet the challenges of flavour analysis

The flavour analysis of volatile compounds remains challenging not only because of their diversity in properties and dynamic range, but also due to the high background noise from food matrix constituents. To improve sensitivity and specificity for a multiclass range of compounds, a combination of solid phase micro-extraction (SPME) devices and low energy electron ionisation (LE-EI) was proposed for the analysis of 36 volatile compounds, using coffee as a model matrix. From a pre-evaluation of devices and extraction modes, the combined use of direct immersion-stir bar sorptive extraction and headspace-thin-film SPME (SBSE-TFSPME) was selected to increase compound recovery, and further optimised for extraction temperature (88 °C) and time (110 min). Furthermore, to complement sample preparation by improving method specificity, a LE-EI technique was developed by evaluating the effect of ionisation energy, source temperature, and emission current on the formation of the diagnostic molecular ions and their preservation. This LE-EI method (15 eV, 150 °C, 0.3 μA) was validated with SBSE-TFSPME as a complete workflow in coffee matrices, and was found to possess good repeatability (intra-day RSD: 1.6-7.3 %), intermediate precision (inter-day RSD: 4.1-12.2 %), and linearity (R² > 0.98). Even for complex coffee samples, the method detection limit reached the pg/mL range (e.g. 2,4,5-trimethylthiazole was detected at 15 pg/mL). In conclusion, this study provided insights on the potential of SPME and LE-EI to improve the sensitivity and specificity of analysis for a range of volatile compounds from food and other complex matrices.

Method Validation and Evaluation of Safrole Persistence in Cowpea Beans Using Headspace Solid-Phase Microextraction and Gas Chromatography

Bioinsecticides are regarded as important alternatives for controlling agricultural pests. However, few studies have determined the persistence of these compounds in stored grains. This study aimed at optimizing and validating a fast and effective method for extraction and quantification of residues of safrole (the main component of Piper hispidinervum essential oil) in cowpea beans. It also sought to assess the persistence of this substance in the grains treated by contact and fumigation. The proposed method used headspace solid-phase microextraction (HS-SPME) and gas chromatography with a flame ionization detector (GC/FID). Factors such as temperature, extraction time and type of fiber were assessed to maximize the performance of the extraction technique. The performance of the method was appraised via the parameters selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), precision, and accuracy. The LOD and LOQ of safrole were 0.0057 and 0.019 μg kg⁻¹, respectively and the determination coefficient (R²) was >0.99. The relative recovery ranged from 99.26 to 104.85, with a coefficient of variation <15%. The validated method was applied to assess the persistence of safrole residue in grains, where concentrations ranged from 1.095 to 0.052 µg kg⁻¹ (contact) and from 2.16 to 0.12 µg kg ⁻¹ (fumigation). The levels measured up from the fifth day represented less than 1% of the initial concentration, proving that safrole have low persistence in cowpea beans, thus being safe for bioinsecticide use. Thus, this work is relevant not only for the extraction method developed, but also for the possible use of a natural insecticide in pest management in stored grains.

Identification and characterization of volatile compounds in Lentinula edodes during vacuum freeze-drying

In this study, modified headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) and electronic nose (E-nose) were utilized to investigate the dynamic aroma changes of Lentinula edodes (L. edodes) at different stages of vacuum freeze drying (VFD). The extraction efficiency of volatile compounds from vacuum freeze-dried L. edodes was improved by optimizing five parameters of the HS-SPME. A total of 50 volatiles were identified in L. edodes from different VFD stages by GC-MS. Alcohols, aldehydes, and volatile sulfur-containing compounds (VSCs) were the main flavor constituents of fresh L. edodes, frozen L. edodes, and secondary dried L. edodes. Aldehydes, ketones, and VSCs were the main aroma groups in L. edodes after primary drying. There were 20 volatiles as key odorants with the odor activity values greater than 1, in which esters appeared only before secondary drying of L. edodes. These findings could contribute to a comprehensive insight into the formation mechanism of flavor in the VFD process of L. edodes. PRACTICAL APPLICATIONS: Lentinula edodes is the second most widely cultivated edible fungus worldwide. It is considered a valuable health food not just because of its abundance of nutrients but also because of its delicious taste. This study investigated the regularity regarding the changes of volatile compounds in L. edodes during vacuum freeze drying. The results of the present study offer valuable knowledge for the formation mechanism of volatile substances in the drying process of L. edodes, which can be beneficial to promote the development and utilization of flavor substances in L. edodes.

Multicriteria decision making for evergreen problems in food science by sum of ranking differences

Finding optimal solutions usually requires multicriteria optimization. The sum of ranking differences (SRD) algorithm can efficiently solve such problems. Its principles and earlier applications will be discussed here, along with meta-analyses of papers published in various subfields of food science, such as analytics in food chemistry, food engineering, food technology, food microbiology, quality control, and sensory analysis. Carefully selected real case studies give an overview of the wide range of applications for multicriteria optimizations, using a free, easy-to-use and validated method. Results are presented and discussed in a way that helps scientists and practitioners, who are less familiar with multicriteria optimization, to integrate the method into their research projects. The utility of SRD, optionally coupled with other statistical methods such as ANOVA, is demonstrated on altogether twelve case studies, covering diverse method comparison and data evaluation scenarios from various subfields of food science.

13-Plex UHPLC-MS/MS Analysis of Hexanal and Heptanal Using Multiplex Tags Chemical Isotope Labeling Technology

In this work, a new series of chemical isotope labeling reagents, levofloxacin-hydrazide-based mass tags (LHMTs) named as LHMT359/360/361/362/363/364/365/366/373/375/376/378/379/381 were first designed and synthesized for the high-throughput analysis of potential biomarkers containing hexanal and heptanal of lung cancer. We exploited a new core structure of levofloxacin-d₃, which significantly enhanced the multiplexing capability. Among them, LHMT359 was used for labeling standard compounds as internal standards for quantification. Using LHMT373-heptanal as dummy template, dummy magnetic molecularly imprinted polymers (DMMIPs) were prepared for magnetic dispersive solid-phase extraction after derivatization procedure. Other 12 LHMTs were established for high-throughput labeling hexanal and heptanal in human serum samples. The presynthesized DMMIPs can selectively extract LHMTs-derivatives of hexanal and heptanal from equally mixed derivatization solutions. The enriched derivatives of hexanal and heptanal were quantified by ultrahigh-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). A single UHPLC-MS/MS run enabled simultaneously quantifying hexanal and heptanal from 12 serum samples only within 2 min. The limits of detection were all 0.5 pM for hexanal and heptanal. The accuracies from human serum samples ranged from -10.2% to +11.0% with the intra- and interday precisions less than 11.3%. Meanwhile, this method was successfully applied for the analysis of hexanal and heptanal in serum samples from healthy people and lung cancer patients. The results show that this method has the significant advantages of high sensitivity, accuracy, selectivity, and analysis-throughput. The method application indicates that the developed method is promising in the screening of suspected lung cancer patients.

Comprehensive analysis of volatile compounds in cold-pressed safflower seed oil from Xinjiang, China

Three varieties of safflower seed oil (SSO) from Xinjiang Autonomous Region, China, were analyzed by headspace solid-phase micro-extraction gas chromatography coupled with mass spectrometry (HS-SPME-GC-MS) to reveal volatile components. Overall, 67 volatile components were determined and four compounds including isoamyl alcohol, caproic acid, n-pentanal, and heptanal were newly identified in SSO as aroma-active components. Meanwhile, 16 compounds were selected by relative odor activity value (ROAV) to evaluate contributions of single compounds to the overall odor (ROAV > 1), in which nonanal, (Z)-6-nonenal, and (E)-2,4-decadienal were the top three contributed substances (ROAV > 70). The sensory panel was described as eight definition terms (grassy, fruity, almond, mushroom, fatty, sweet, paddy, and overall fragrance). Principal component analysis (PCA) revealed a significant separation of three cultivars with the first principal component (PC-1) and the second principal component (PC-2) expressing 73.9% and 23.1%, respectively. Both PCA and ROAV allowed identifying the compounds positively correlated to sensory evaluation.

Release of Fragrances from Cotton Functionalized with Carbohydrate-Binding Module Proteins

Perspiration as a response to daily activity and physical exercise results in unpleasant odors that cause social unrest and embarrassment. To tackle it, functional textiles incorporating fragrances could be an effective clothing deodorizing product. This work presents two strategies for the release of β-citronellol from functionalized cotton with carbohydrate-binding module (CBM)-based complexes (OBP::GQ₂₀::CBM/β-citronellol-approach 1 and CBM::GQ₂₀::SP-DS3-liposome/β-citronellol-approach 2). CBM from Cellulomonas fimi was fused with the odorant-binding protein (OBP::GQ₂₀::CBM) and with an anchor peptide with affinity to the liposome membrane (CBM::GQ₂₀::SP-DS3). In approach 1, OBP fusion protein served as a fragrance container, whereas in approach 2, the fragrance was loaded into liposomes with a higher cargo capacity. The two strategies showed a differentiated β-citronellol release profile triggered by an acidic sweat solution. OBP::GQ₂₀::CBM complex revealed a fast release (31.9% and 25.8% of the initial amount, after 1.5 and 24 h of exposure with acidic sweat solution, respectively), while the CBM::GQ₂₀::SP-DS3-liposome complex demonstrated a slower and controlled release (5.9% and 10.5% of the initial amount, after 1.5 and 24 h of exposure with acidic sweat solution, respectively). Both strategies revealed high potential for textile functionalization aimed at controlled release of fragrances. The OBP::GQ₂₀::CBM/β-citronellol complex is ideal for applications requiring fast release of a high amount of fragrance, whereas the CBM::GQ₂₀::SP-DS3-liposome/β-citronellol complex is more suitable for prolonged and controlled release of a lower amount of β-citronellol.

Physicochemical characterization and quality of Dangshan pear wines fermented with different Saccharomyces cerevisiae

Three commercial yeasts strains, namely, Saccharomyces cerevisiae SY, DV10, and Drop Acid Yeast, were used for Dangshan pear wine fermentation. Monitoring main physical and chemical indexes and scoring comprehensive sensory characteristics to find a suitable yeast to produce Dangshan pear wine. The fermentation cycle of SY was short (15 days), and the SY-fermented wine had a suitable sugar-acid ratio, with a residual sugar content of 3.13 ± 0.05 g/L, total acid content of 3.40 ± 0.11 g/L, and ethanol content of 14.1 ± 0.27% (v/v). Additionally, 42 flavor compounds were detected in fermented Dangshan pear wine, and the total amount of flavor compounds was highest in the SY wine (2,584.72 μg/L). Combined with the comprehensive sensory evaluation scores, these results suggest that Saccharomyces cerevisiae SY was the most suitable strain to produce Dangshan pear wine. PRACTICAL APPLICATIONS: In this study, we compared the physical and chemical indicators of pear wine brewed by different Saccharomyces cerevisiae in the process of fermentation and the final quality of pear wine products. It was concluded that the pear wine produced by Saccharomyces cerevisiae SY had good quality. The study found a strain suitable for the fermentation of pear wine and provided a theoretical basis for the industrial production of pear wine. Next, we can try to use Saccharomyces cerevisiae SY for large-scale production of pear wine and try to sell it on the market.

Current Trends in Fully Automated On-Line Analytical Techniques for Beverage Analysis

The determination of target analytes in complex matrices such as beverages requires a series of analytical steps to obtain a reliable analysis. This critical review presents the current trends in sample preparation techniques based on solid phase extraction miniaturization, automation and on-line coupling. Techniques discussed include solid-phase extraction (SPE), solid-phase microextraction (SPME), in-tube solid-phase microextraction (in-tube SPME) and turbulent-flow chromatography (TFC). Advantages and limitations, as well as several of their main applications in beverage samples are discussed. Finally, fully automated on-line systems that involve extraction, chromatographic separation, and tandem mass spectrometry in one-step are introduced and critically reviewed.