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Aroma is one of the main characteristics of coffee specimens. Different mixtures of Arabica and Robusta coffees are usually found in the market to offer specific aroma or flavor profiles to consumers. However, the mixed samples or their proportions are not always identified in the product labels. Since the price of Arabica is much higher than that of Robusta, this lack of information is not only an economical issue but a possible fraud to consumers, besides the potential allergic reaction that these mixtures may trigger in some individuals. In this paper, two sample preparation techniques were compared before the analysis of the total volatile organic compounds (VOCs) found in Robusta, Arabica, and in the mixture from both coffee types. The comparison of the signals obtained from the analyses showed that the VOCs concentration levels obtained from the headspace (HS) analyses were clearly higher than those obtained from the pre-concentration step where an adsorbent, an active charcoal strip (ACS + HS), was used. In the second part of this study, the possibility of using the headspace gas-chromatography ion mobility spectrometry (HS-GC-IMS) for the discrimination between Arabica, Robusta, and mixed coffee samples (n = 30) was evaluated. The ion mobility sum spectrum (IMSS) obtained from the analysis of the HS was used in combination with pattern recognition techniques, namely linear discrimination analysis (LDA), as an electronic nose. The identification of individual compounds was not carried out since chromatographic information was not used. This novel approach allowed the correct discrimination (100%) of all of the samples. A characteristic fingerprint for each type of coffee for a fast and easy identification was also developed. In addition, the developed method is ecofriendly, so it is a good alternative to traditional approaches.

Cellulose and lignin, sourced from biomass, hold potential for innovative bioprocesses and biomaterials. However, traditional fractionation and purification methods often rely on harmful chemicals and high temperatures, making these processes both hazardous and costly. This study introduces a sustainable approach for fractionating acacia wood, focusing on both cellulose and lignin extraction using a deep eutectic solvent (DES) composed of choline chloride (ChCl) and levulinic acid (LA). A design of experiment was employed for the optimization of the most relevant fractionation parameters: time and temperature. In the case of the lignin, both parameters were found to be significant variables in the fractionation process (p-values of 0.0128 and 0.0319 for time and temperature, respectively), with a positive influence. Likewise, in the cellulose case, time and temperature also demonstrated a positive effect, with p-values of 0.0103 and 0.028, respectively. An optimization study was finally conducted to determine the maximum fractionation yield of lignin and cellulose. The optimized conditions were found to be 15% (w/v) of the wood sample in 1:3 ChCl:LA under a treatment temperature of 160 °C for 8 h. The developed method was validated through repeatability and intermediate precision studies, which yielded a coefficient of variation lower than 5%. The recovery and reuse of DES were successfully evaluated, revealing remarkable fractionation yields even after five cycles. This work demonstrates the feasibility of selectively extracting lignin and cellulose from woody biomass using a sustainable solvent, thus paving the way for valorization of invasive species biomass.

Grapevine canes are viticulture waste that is usually discarded without any further use. However, recent studies have shown that they contain significant concentrations of health-promoting compounds, such as stilbenes, secondary metabolites of plants produced as a response to biotic and abiotic stress from fungal disease or dryness. Stilbenes have been associated with antioxidant, anti-inflammatory, and anti-microbial properties and they have been tested as potential treatments of cardiovascular and neurological diseases, and even cancer, with promising results. Stilbenes have been described in the different genus of the Vitaceae family, the Vitis genera being one of the most widely studied due to its important applications and economic impact around the world. This review presents an in-depth study of the composition and concentration of stilbenes in grapevine canes. The results show that the concentration of stilbenes in grapevine canes is highly influenced by the Vitis genus and cultivar aspects (growing conditions, ultraviolet radiation, fungal attack, etc.). Different methods for extracting stilbenes from grapevine canes have been reviewed, and the extraction conditions have also been studied, underlining the advantages and disadvantages of each technique. After the stilbenes were extracted, they were analyzed to determine the stilbene composition and concentration. Analytical techniques have been employed with this aim, in most cases using liquid chromatography, coupled with others such as mass spectrometry and/or nuclear magnetic resonance to achieve the individual quantification. Finally, stilbene extracts may be applied in multiple fields based on their properties. The five most relevant are preservative, antifungal, insecticide, and biostimulant applications. The current state-of-the-art of the above applications and their prospects are discussed.

The present investigation endeavors to optimize a method based on enzyme-assisted extraction for the efficient retrieval of bioactive compounds from mulberry, leveraging its notable health-promoting properties. A combined approach of Plackett–Burman design followed by Box–Behnken design was employed for determining the crucial extraction parameters and subsequently, refining the process. Optimal conditions consisted of heating 0.15 g of mulberry at 40 °C, using 15 mL of 70% EtOH as a solvent at pH 4, 38.46 enzyme units per g of sample, and shaking at 200 rpm. The optimum extraction time study revealed that 5 min of extraction was sufficient to reach the maximum concentration of the bioactive compound. The repeatability and intermediate precision assessment exhibited a coefficient of variation below 5%. Among the diverse mulberry varieties scrutinized, Morus nigra showed the highest anthocyanin content (27.90 ± 2.14 mg/100 g), while Morus rubra showed the highest concentration of phenolic compounds (121.10 ± 19.56 mg/100 g). Moreover, the extracted compounds showcased significant antioxidant and antimicrobial properties.

Deep eutectic solvents represent an important alternative in the field of green solvents due to their low volatility, non-toxicity, and low synthesis cost. In the present investigation, we propose the production of enriched polyphenolic extracts from maritime pine forest residues via an ultrasound-assisted approach. A Box–Behnken experimental design with a response surface methodology was used with six variables to be optimized: solid-to-solvent ratio, water percentage, temperature and time of extraction, amplitude, and catalyst concentration. The mixture of levulinic and formic acids achieved the highest extraction yield of polyphenols from pine needle and bark biomass. In addition, the solid-to-solvent ratio was found to be the only influential variable in the extraction (p-value: 0.0000). The optimal conditions were established as: 0.1 g of sample in 10 mL of LA:FA (70:30%, v/v) with 0% water and 0 M H2SO4 heated to 30 °C and extracted during 40 min with an ultrasound amplitude of 80% at 37 kHz. The bioactive properties of polyphenol-enriched extracts have been proven with significant antioxidant (45.90 ± 2.10 and 66.96 ± 2.75 mg Trolox equivalents/g dw) and antimicrobial activities. The possibility to recycle and reuse the solvent was also demonstrated; levulinic acid was successfully recovered from the extracts and reused in novel extractions on pine residues. This research shows an important alternative to obtaining polyphenol-enriched extracts from forest residues that are commonly discarded without any clear application, thus opening an important window toward the valorization of such residues.

Several investigations have proven the presence of anthocyanins in different parts of acai plants. These compounds are responsible for the notable therapeutic properties of acai such as antioxidant, antimicrobial, anti-inflammatory, anticancer, and anticonvulsant. We have therefore optimized an enzyme-assisted extraction method for the anthocyanins found in acai, to be subsequently applied in many fields such as agrifood, medicine, or cosmetics. A Plackett-Burman design with seven variables (time of extraction, pH, temperature, agitation, percentage of ethanol in the solvent, amount of sample, and units of enzyme) was employed to determine the predominant extraction variables, of which four were categorized as influential. Subsequently, a Box-Behnken design-response surface methodology made it possible to determine the degree of influence from these variables and their optimal values. The optimal conditions were established as 0.1 g of acai heated up to 60 degrees C and extracted using 15 mL of solvent with pH 4 and 40% ethanol, 500 units of enzyme per gram of sample, and agitation at 150 rpm for 15 min. The repeatability and intermediate precision of the developed method were confirmed by variation coefficients below 5%. Finally, the developed method was compared against the extensively used maceration and ultrasound-assisted extraction methods.

Gas chromatography (GC) and mass spectrometry (MS) are widely used techniques in the analysis of complex mixtures due to their various advantages, such as high selectivity, reproducibility, precision, and sensitivity. However, the data processing is often complex and time-consuming and requires a great deal of experience, which might be a serious drawback in certain areas, such as quality control, or regarding research in the field of medicine or forensic sciences, where time plays a crucial role. For these reasons, some authors have proposed the use of alternative data processing approaches, such as the total ion chromatogram or total mass spectrum, allowing these techniques to be treated as sensors where each retention time or ratio m/z acts as a sensor collecting total intensities. In this way, the main advantages associated with both techniques are maintained, but the outcomes from the analysis can be reached in a faster, simpler, and an almost automated way. In this review, the main features of the GC- and MS-based analysis methodologies and the ways in which to apply them are highlighted. Moreover, their implementation in different fields, such as agri-food, forensics, environmental sciences, or medicine is discussed, highlighting important advantages as well as limitations.

This work has been supported by the project \"EQC2018-005135-P\" (Equipment for liquid chromatography by means of mass spectrometry and ion chromatography) of the State Subprogram of Research Infrastructures and Technical Scientific Equipment.

Wine lees, an important by-product of the wine industry, pose a major environmental problem due to the enormous quantities of solid–liquid waste that are discarded annually without defined applications. In this study, the optimization of a method based on a Box–Behnken design with surface response has been carried out to obtain extracts with high anthocyanin content and potent antioxidant activity. Six variables have been considered: %EtOH, temperature, amplitude, cycle, pH, and ratio. The developed method exhibited important repeatability properties and intermediate precision, with less than 5% CV being achieved. Furthermore, these novel methods were successfully applied to diverse wine lees samples sourced from Cabernet Sauvignon and Syrah varieties (Vitis vinifera), resulting in extracts enriched with significant anthocyanin content and noteworthy antioxidant activity. Additionally, this study evaluated the influence of grape variety, fermentation type (alcoholic or malolactic), and sample treatment on anthocyanin content and antioxidant activity, providing valuable insights for further research and application in various sectors. The potential applications of these high-quality extracts extend beyond the winemaking industry, holding promise for fields like medicine, pharmaceuticals, and nutraceuticals, thus promoting a circular economy and mitigating environmental contamination.

Betalains are water-soluble pigments that have exhibited important pharmacological properties such as antioxidant, anticancer, antilipidemic and antimicrobial activity. These compounds have been isolated in numerous purple plants or fruits, as is the case of the wild species under the Opuntia genus. The fruits of these species are often disregarded because of their small size as well as the frequent presence of prickles. Based on this, this research has as its objective the optimization of a method based on ultrasound-assisted extraction to obtain extracts enriched with betalains from a wild Opuntia species (Opuntia dillenii (Ker Gawl.) Haw.). Four variables (%EtOH in the solvent, temperature of extraction, ultrasound amplitude and cycle) were selected using a Box-Behnken design. The quadratic interaction of %EtOH and the interaction of %EtOH-cycle have proven to be influential variables at 95% confidence. The conditions to obtain the highest betalain concentration were 100 mg of pulp with 20 mL (60%:40% EtOH:H2O) solvent at 20 degrees C at 24% amplitude and 0.2 cycle for 10 min. The suitability and reliability of the method were evaluated with repeatability and intermediate precision tests obtaining CVs <5%. Finally, the developed method has been employed in the analysis of five Opuntia commercial samples and obtained significant antioxidant activity of the extracts, confirming its applicability.