Aldehyde Content Research Articles

Influence of Electrohydrodynamics on the Drying Characteristics and Volatile Components of Ginger

This article studies the electrohydrodynamic drying of ginger. In this work, drying experiments were performed in an electrohydrodynamic drying (EHD) system at various AC voltages (0 kV (control), 15 kV, 20 kV, 25 kV, and 30 kV). The drying properties and volatile components of ginger were thoroughly examined and studied using IR spectroscopy and GC–MS. The findings revealed that electrohydrodynamics significantly increased the drying rate and reduced the drying time of ginger, with a sevenfold increase in drying rate and a one-third reduction in drying time at 30 kV. The peak of the infrared spectrum of ginger remains unchanged. We found 240 volatile chemicals under different drying voltages. The primary volatile chemicals were esters and aldehydes. The ginger products dried at 30 kV had the lowest aldehyde concentration. These findings give an experimental and theoretical foundation for applying electrohydrodynamics to the subject of ginger drying.

Composition of the Low Molecular Weight Metabolome of Potamogeton perfoliatus (Potamogetonaceae) as an Indicator of the Transformation of the Ecological State of the Littoral Zone

The composition and nature of changes in the low-molecular-weight metabolome (NM) of Potamogeton perfoliatus L., growing in 6 biotopes of Lake Ladoga with different types of the anthropogenic load has been analyzed. According to the research results, it was found that the total number of low molecular weight organic compounds (LMWOCs) in the P. perfoliatus NM composition is directly dependent on anthropogenic load, which is well marked by the development of cyanobacteria. The greater the intensity of pollution or eutrophication of waters, or the higher the number of cyanobacteria, the lower the total number of LMWOCs and their concentration. A strongly pronounced dependence of the total concentrations of groups of NM compounds on the anthropogenic disturbance of the biotope and the concentration of cyanobacteria was revealed. A decrease in the number, relative amount, total concentration of carboxylic acids, number and content of unsaturated fatty acids, and, at the same time, an increase in the composition and content of phenols and the total content of aldehydes and ketones depends on an increase in anthropogenic pressure. The specific composition of NM of pierced pondweed depends on its response to biotic and abiotic factors of the aquatic environment, including anthropogenic ones. The revealed features of the change in the composition of P. perfoliatus NM make it possible to use it as an integral indicator of the anthropogenic impact on the littoral biotopes of water bodies and the deterioration of their ecological state.

Towards the Development of Novel, Point-of-Care Assays for Monitoring Different Forms of Antioxidant Activity: The RoXstaTM System

(1) Background: This study set out to develop a series of simple, novel, rapid methods for assessing different forms of antioxidant activity. (2) Methods: An ABTS platform was used to engineer: (i) an electrochemical post-activation assay to assess free radical scavenging activity; (ii) an electrochemical pre-activation strategy to assesses the suppression of free radical formation; (iii) a horseradish peroxidase-mediated oxidation system to monitor hydrogen peroxide scavenging activity and (iv) a cumene peroxide-hematin system to determine the ability of samples to scavenge the mixture of organic peroxides and peroxyl and alkoxyl radicals generated in the presence of these reagents. Each assay was assessed against a panel of candidate antioxidant compounds to determine their relative activities and specificities. In addition, human semen samples were analyzed to determine how the results of these antioxidant assays correlated with semen quality. (3) Results: All 4 assays revealed dose-dependent antioxidant activity on the part of vitamin C, N-acetyl cysteine, hypotaurine, BSA, melatonin, glutathione, resveratrol and epigallocatechin gallate. The other compounds tested either completely lacked antioxidant activity or were only active in one of the assays. Using unfractionated human semen as an exemplar of biological fluids rich in antioxidants, the outputs from the individual assays were found to reflect different aspects of semen quality. When the data from all 4 assays were combined, accurate predictions were generated reflecting the importance of oxidative stress in defining semen quality as reflected by sperm count, seminal lipid aldehyde content, sperm DNA damage and free radical generation by the sperm mitochondria. (4) Conclusions: The methodologies described in this paper constitute the basis for rapid, point-of-care assessments of oxidative stress.

Effects of Nitrogen Concentration in Nutrient Solution on Growth, Yield and Phytochemical and Aromatic Compounds of Persicaria minor Cultivated Using Hydroponics System

Persicaria minor, locally known as kesum and belonging to the family Polygonaceae, is a widely used aromatic herb in Malaysia. Cultivating kesum hydroponically using a deep-water culture (DWC) system presents an alternative method for growers to enhance crop yields. This system delivers a liquid fertilizer solution directly to the plant roots, eliminating the need for a growth medium or water flow. Kesum contains phytochemical compounds such as quercetin-3-glucuronide and quercitrin, which have medicinal properties. The primary objective of this study was to assess the effects of nitrogen concentration on the growth, yield, phytochemical (quercetin-3-glucuronide and quercitrin) and aromatic (aldehyde and caryophyllene) content of kesum cultivated in a hydroponic system. Plants were grown under four nitrogen concentration regimes: 200 mg/L, 100 mg/L, 50 mg/L, and 0 mg/L. The experiment was conducted under a side-netted rain shelter and arranged in a Randomized Complete Block Design (RCBD) with four replications. The plants were harvested eight weeks after planting. The result indicted those supplemented with 100 mg/L of nitrogen exhibited the best growth performance and biomass yield, along with the highest levels of aromatic compounds (aldehyde C-10: 5.80% and aldehyde C-12: 12.23%). Plants treated with 50 mg/L of nitrogen produced the highest amounts of quercetin-3-glucuronide (98.261 µg/mL) and quercitrin (61.367 µg/mL) compared to other treatments. Additionally, plants receiving 200 mg/L of nitrogen had the highest caryophyllene content (12.53%). In conclusion, the deep-water culture system in hydroponics can effectively cultivate kesum, allowing for adjustments in nitrogen concentration to achieve optimal yields, phytochemical levels, or aromatic compound production based on specific objectives.

Effects of Five Different Withering Methods on the Composition and Quality of Congou Black Tea.

To explore the effects of different withering methods on the quality of Congou black tea, this study focused on five different withering methods: natural withering, warm-air withering, sun-natural combined withering, sun withering, and shaking withering. Gas chromatography‒mass spectrometry (GC‒MS), high-performance liquid chromatography (HPLC), and ion-exchange chromatography techniques were used to analyze the nonvolatile and volatile components and composition of the tea. The results revealed significant differences (p < 0.05) in the contents of nonvolatile constituents including caffeine, polyphenols, soluble sugars, free amino acids and their components, theaflavins, thearubigins, and catechins among the five different withering methods, with varying degrees of correlation between these components. A total of 227 aroma compounds were detected, and significant differences in the contents of alcohols, aldehydes, and ketones were observed. A relative odor activity value (ROVA) analysis of the aroma compounds revealed that 19 compounds had an ROVA > 1. Among them, benzylaldehyde, trans-2-decenal, decanal, benzaldehyde, nonanal, hexanal, trans-linalool, and geraniol from the shaking withering method had significantly higher ROVA values than those from the other withering methods, which may be the reason for the prominent floral and fruity aroma of shaking withering. This study revealed the impact of different withering methods on the quality of Congou black tea, providing a scientific basis for the development of Congou black tea with different flavors and the improvement of Congou black tea processing techniques.

Synthesis of Carboxylate-Dialdehyde Cellulose to Use as a Component in Composite Thin Films for an Antibacterial Material in Wound Dressing.

Wound infections can lead to life-threatening infection and death. Antibacterial materials from biopolymers in the form of films are a promising strategy for wound dressings. Carboxylate-dialdehyde cellulose (CDAC) is a proper candidate for use as an antibacterial material due to its biocompatibility, nontoxicity, and antibacterial property. Additionally, CDAC can be synthesized from cellulose through environmentally friendly and nontoxic methods. Thus, this study aims to synthesize CDAC from microcrystalline cellulose (MCC) PH102 and use it in composite films for an antibacterial application. The CDAC was synthesized using Fe2+/H2O2, followed by NaIO4 oxidation. The obtained CDAC was characterized in terms of carboxylate and aldehyde content as well as FTIR and XRD spectra. The CDAC was mixed with HPMC in different ratios to prepare films. To determine the optimal formulation for clindamycin HCl loading, the films were evaluated for morphology, mechanical properties, and swelling ratio. Finally, the films containing clindamycin HCl were evaluated for drug loading content, in vitro drug release, and antibacterial activity. This study found that CDAC contained 2.1 ± 0.2 carboxylate and 4.15 ± 0.2 mmol/g of aldehyde content. The FTIR spectra confirmed the successful synthesis. X-ray diffractograms indicated that CDAC was less crystalline than MCC. The film, consisting of CDAC and HPMC E50 in the ratio of 2:1 (D2H1), was identified as the most suitable for clindamycin HCl loading due to its superior appearance, mechanical strength, and swelling properties compared to other formulations. D2H1 exhibited a high drug loading capacity (91.49 ± 5.48%) and demonstrated faster drug release than the film composed only of HPMC because of the higher swelling ratio and lower mechanical strength. This formulation was effective against Staphylococcus aureus (MSSA), S. aureus (MRSA), and Pseudomonas aeruginosa. Furthermore, the D2H1 film containing clindamycin HCl showed a larger inhibition zone against these bacteria, likely due to a synergistic effect. This study found that CDAC has the potential to be applied as an antibacterial material for wound dressing.

Comparative analysis of meat quality of Laiwu black, Minxinan black and Hyla rabbits

Abstract. The meat rabbit industry in China relies on foreign breeds and synthetic lines; the development of superior domestic breeds has not yet been fully realised. We compared the meat quality of two Chinese local breeds of black rabbits (Laiwu black and Minxinan black) and Hyla commercial rabbits, to provide a reference for the utilisation of meat rabbit breeds. In the present study, 35 d old Laiwu black rabbits, Minxinan black rabbits, and Hyla rabbits (20 rabbits each) were selected and reared under identical feeding and management conditions for 7 weeks, after which 10 randomly selected rabbits from each group were slaughtered for the analysis of meat quality. The a∗ (redness) value of the two local breeds was significantly higher than that of Hyla rabbits (p&lt;0.01). The shearing force and drip loss of Laiwu black rabbits were significantly lower than those of the other groups (p&lt;0.05). The two local breeds exhibited significantly higher myoglobin levels than Hyla rabbits (p&lt;0.01), while melanin was highest in the meat of Minxinan black rabbits. The essential amino acids (valine, isoleucine, leucine and lysine) were significantly lower in Minxinan black rabbits than in the other groups (p&lt;0.05). Aldehyde (heptanal, octanal) contents in Minxinan black meat were significantly higher than those of the other groups (p&lt;0.01); however, nucleotide (guanine, adenine) contents were significantly lower (p&lt;0.01). Unsaturated fatty acids (oleic, linoleic, α-linolenic) were significantly higher in the meat of Laiwu black rabbits than in those of the other groups (p&lt;0.05). Both Laiwu black and Minxinan black rabbits have certain advantages in terms of nutritional indicators while also having good meat colour and flavour. The results of this study provide a theoretical reference for the research and development of meat rabbit breeds.

Facile photometric quantification of aldehyde content in oxidized starches using 2-aminobenzamide oxime as an aldehyde selective reagent

AbstractThe oxidation of starch to aldehyde starch or dialdehyde starch introduces aldehyde groups to the starch core structure. This functionalization enables a wide range of further derivatization, e.g., oxidation to the corresponding carboxylic acid or functionalization to the corresponding amine via imine formation and reduction, which can be used for cross-linking. Herein, we report a novel method for efficiently quantifying these aldehyde groups based on the selective adduct formation of 2-aminobenzamide oxime (ABAO) and aldehydes. We initially implemented this photometric assay for C6-oxidized aldehyde starch using a plate reader, enabling parallel analysis of multiple samples in a fraction of the time and consistent with the conventional titration methods. Complementing this stream-lined analytical approach, we present an abbreviated workflow for faster downstream processing of reaction samples toward analysis. All of this was performed at a very small scale, cutting costs for (expensive) reagents and solvents, as well as drastically reducing working time. Finally, we also demonstrate our assay's applicability for quantifying the two aldehyde groups formed in dialdehyde starch derived from NaIO4 oxidation. Graphical abstract

Dynamic imine crosslinking for waterproof starch plastic with tunable mechanical properties

Starch-based plastics offer a potential solution to environmental pollution and can reduce the dependence on petroleum-based plastics. However, effectively preparing starch-based plastics with moisture resistance and high strength remains challenging. Herein, dialdehyde starch (DAS) with different degrees of oxidation was first synthesised. The molecular weight and crystallinity of DAS decreased depending on the aldehyde content, as determined through scanning electron microscopy, X-ray diffraction and molecular weight analyses. Subsequently, a sustainable starch plastic (DAS-DA) was prepared via the dynamic imine crosslinking of DAS with diamines. The influence of the degree of oxidation of DAS on the structure and properties of DAS-DA was systematically investigated. No linear relationship was observed between the tensile strength of DAS-DA and the aldehyde content of DAS. When the aldehyde content was 41.1 %, the resulting DAS41-DA exhibited optimal mechanical strength (27.8 MPa), exceeding that of most reported starch-based plastics. In addition, owing to the presence of imine crosslinking networks, DAS41-DA exhibited excellent water and solvent resistance (>60 days), good thermal stability (456 °C–462 °C) and excellent reprocessability and biodegradability. These findings provide a theoretical basis for the preparation of high-performance bioplastics from aldehyde-containing polysaccharides.

Unravelling the formation of characteristic aroma of traditional braised pork through untargeted and targeted flavoromics

Untargeted flavoromics and targeted quantitative analysis of key aroma compounds, and analysis of dynamic change of aroma precursors concentration were used to investigate the aroma evolution of traditional braised pork and the underlying mechanism. The results indicated that lipid oxidation dominated at early cooking stage (0th–45th min), resulting in an increased concentration of most aldehydes, alcohols, ketones, such as hexanal, heptanal, octanal, nonanal, (E)-2-octenal, benzaldehyde, 1-octen-3-ol, and 2,3-octanedione, accompanied with an enhanced unpleasant fatty odor. From 45th to 73rd min, the seasonings alleviated excessive oxidation of unsaturated fatty acids accompanied with decreased aldehydes. Moreover, the diffusion of glucose and amino acids from seasonings to lean meat promoted the consumption of endogenous ribose and amino acids in meat through Maillard reaction, and facilitated the formation of dimethyl trisulfide, dimethyl disulfide, methanethiol, and 2-furfural, which contributed to the meaty, sauce-like, and sweety aroma, thus formed the characteristic aroma of traditional braised pork.

Effects of surimi by-product hydrolysates on processing quality and difference analysis of volatile compounds of silver carp surimi gel

The aim of this study was to investigate the effects of surimi by-product hydrolysates (SBPHs) on the processing quality, gel characteristics, microstructure, and volatile compounds of surimi. The results showed that the addition of SBPHs improved the water holding capacity (95.18% and 94.32%), texture property, and gel characteristic (546.04 g cm) of the surimi gel, reduced the cooking loss (7.15%) and aperture area (34.10%) of the surimi gel (P < 0.05), causing no difference in their whiteness (P > 0.05). The SBPHs reduced the free water and increased the immobilized water of the gel. At the same time, SBPHs made tighter cross-linking of the surimi gel proteins. The results of gas chromatography-ion mobility spectrometry showed that 62 volatile flavor compounds were detected in each group of surimi, and the relative contents of aldehydes, alcohols, and ketones were relatively high. A total of 19 volatile flavor compounds were selected as the potential markers in samples by orthogonal partial least square siscriminant analysis. The additions of SBPHs (0.6% and 1.2%) in this study were much lower than those of commercial cryoprotectant (6%). In conclusion, SBPHs emerges as a potential cryoprotectant for the surimi industry and have promising advantages in enhancing the quality of surimi.

Changes of physicochemical and volatile flavor compounds of dry-cured Diqing Tibetan pig hams during fermentation

This study aimed to explore the flavor formation mechanism of Diqing Tibetan pig hams by investigating changes of their physicochemical and volatile flavor compounds during fermentation (0, 30, 90, 180, 360, and 540d) using amino acid analyzer , texture profile analysis, and gas chromatography-ion mobility spectroscopy (GC-IMS). During fermentation, the hams significantly decreased in moisture and centrifugal loss, while increased in chewiness, hardness, and proteolysis index, with their free amino acids content reaching the maximum at 360d and significantly decreasing at 540d. GC-IMS identified 78 volatile organic compounds, with the highest total content of alcohols and aldehydes at 180d, ketones and heterocycles at 360d, and esters at 540d. PLS-DA screened 24 volatile flavor markers, with aldehyde (2-methyl-2-propenal), ketone (2-heptanone-D), alcohol (3-methylbutanol-D), ester (ethyl3-methylbutanoate-M), and heterocyclic substances (2,3-dimethylpyrazine-M) as the main VFMs at 360d. The unique flavor of 540d Diqing Tibetan pig hams was attributed to their higher content of 3-methyl-2-butenal, 3-(methylthio) propanal, ethyl caproate and 2-butanone. These findings provide a scientific basis for the flavor formation mechanism of hams which favoring the further development processing strategies for Diqing Tibetan pig.

Extra Virgin Olive Oil from Stoned Olives with Oxygen Supply during Processing: Impact on Volatile and Phenolic Fraction and Sensory Characteristics.

The improvement of the extra virgin olive oil (EVOO) extraction process involves the proper management of endogenous enzymes of the olive fruit and all the technological conditions that can affect their activities. Coratina and Peranzana cultivars were processed to assess the influence of different technologies for fruit breaking (crushing and stoning) with and without controlled oxygen addition during this critical phase. The study of volatile compounds revealed that the enzymes that are responsible for their genesis during the technological process were significantly affected by oxygen addition in both the systems of fruit crushing. The results from the stoning technology proved that the quality improvement was a consequence of the prevention of the seed breaking and the oxidation catalyzed by the olive stone enzymes. In Peranzana EVOOs, it was possible to increase the aldehyde concentration up to 97% using stoning technology with a 0.2 L/min oxygen addition compared with traditional crushing. At the same time, non-significant reductions in phenolic compounds were detected when comparing crushing and stoning with and without the addition of oxygen, and similar trends were observed for the two studied cultivars. The sensory analyses confirmed the differences in phenolic and volatile composition detected in the EVOO samples.

Combined Analysis of Transcriptome and Metabolome Provides Insights in Response Mechanism under Heat Stress in Avocado (Persea americana Mill.)

Plants generate a range of physiological and molecular responses to sustain their growth and development when suffering heat stress. Avocado is a type of tropical fruit tree with high economic value. Most avocado cultivars delete, wither, or even die when exposed to heat stress for a long time, which seriously restricts the introduction and cultivation of avocados. In this study, samples of a heat-intolerant variety (‘Hass’) were treated under heat stress, and the transcriptomics and metabolomics were analyzed, with the expectation of providing information on the variety improvement and domestication of avocados. The differentially expressed genes identified using transcriptome analysis mainly involved metabolic pathways such as plant hormone signal transduction, plant–pathogen interaction, and protein processing in the endoplasmic reticulum. Combined transcriptome and metabolome analysis indicated that the down-regulation of Hass.g03.10206 and Hass.g03.10205 in heat shock-like proteins may result in the reduced Trehalose and Sinapoyl aldehyde content. Metabolomics analysis results indicated that the decrease in Trehalose and Sinapoyl aldehyde content may be an important factor for heat intolerance. These results provide important clues for understanding the physiological mechanisms of adaptation to heat stress in avocados.

Comprehensive investigation on non-volatile and volatile flavor compounds in different varieties of rose tea by UPLC-Q-TOF-MS/MS-based metabolomics and GC-IMS, GC-MS

This study aimed to analyze the quality differences of different varieties of rose tea. Ultra-high-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS) was used to detect the metabolites in different varieties of rose to find out the differential metabolites.Forty-four phenylpropionic acid and polyketone compounds were found to the main differential metabolites in 6 different varieties of roses. Gas chromatography ion mobility spectrometry (GC-IMS) results revealed the presence of 15 potential differential compounds among different varieties of roses, with 1-penten-3-one (monomer) and ethyl propionate being the two most significantly different substances among the six different varieties of roses. GC-MS analysis of volatile flavor compounds in different varieties of rose tea showed that the concentrations of aldehydes, alcohols, alkanes, and phenols in XS rose tea were the highest, being 4.133 µg/g, 14.873 µg/g, 3.039 µg/g, and 2.399 µg/g, respectively. The concentrations of ketones, heterocyclic compounds, and ethers in KS rose tea are the highest, being 4.344 µg/g, 0.752 µg/g, and 0.234 µg/g, respectively. Phenyl-ethanol, citronellol, octanoic acid ethyl ester, and decanoic acid ethyl ester are considered to be the main factors in the formation of characteristic aromas in different varieties of rose tea.

Effects of phenolic acid grafted-chitosan hydrocolloids on the aldehyde contents from lipid oxidation in golden pompano (Trachinotus blochii) fillets during pan-frying

The effects of phenolic acid grafted-chitosan hydrocolloids (CS-g-GA/FA) on aldehyde contents from lipid oxidation in golden pompano fillets during pan-frying was investigated with an established high-performance liquid chromatography-mass spectrum method. Results indicated that pan-frying induced profound lipid oxidation and aldehydes generation with propanal, hexanal, nonanal, trans, trans-2,4-decadienal, and 4-hydroxy-2-nonenal as the abundant species. CS-g-FA and CS-g-GA effectively decreased their contents by 23.74–27.42 %, 61.69–67.42 %, 41.83–53.91 %, 29.91–48.79 %, and 61.57–65.39 % after 3 min. Most aldehyde contents decreased with the extension of pan-frying time due to the volatilization and reaction. In terms of substrate depletion, CS-g-phenolic acids effectively inhibited unsaturated fatty acids oxidation due to their decent antioxidant activity than CS. The significant lower retention rates of aldehydes in the CS-g-phenolic acids groups compared with control in chemical mode confirmed the carbonyl ammonia condensation. These results suggested that CS-g-phenolic acids serve as novel coating to reduce hazardous compounds during aquatic products thermal processing.

Effects of heat treatments on the stability, antioxidant activity and volatiles of milk and whey ultrafiltration permeates

Milk (MP) and whey (WP) ultrafiltration permeates were obtained from different dairy processing plants. The effects of pH (4 or 6) and heat treatments (63 °C, 30 min; or 110 °C, 6 min) on permeate stability were measured by the increase of turbidity, and precipitation of nitrogen and calcium. The antioxidant activity and the production of volatiles compounds, as affected by heat treatments, was also evaluated. WP showed a higher sensitivity to heat treatments than MP. Increasing heating temperature reduced the stability of permeates, with an intensified effect at pH 6. Calcium precipitation was the main factor responsible for the increase in turbidity. Lowering the pH to 4 prior to heating strongly limited the development of turbidity. Sterilisation improved antioxidant activity of both permeates, with a greater effect on WP. Sterilisation had no effect on the concentration of volatile aldehydes but promoted the formation of volatile sulfur compounds, and more significantly in WP.

Characterization of Camphene- and Fenchol-Based Hydrophobic Eutectic Solvents and Their Application in Aldehyde Extraction.

Binary terpenoid-based eutectic systems consisting of the natural substances camphene (CA), fenchol (FE), thymol (TH), menthol (ME), dodecanoic acid (DA), and 1-dodecanol (DO) are synthesized and screened for their Solid-Liquid Equilibrium (SLE) and eutectic compositions. Out of nine eutectic systems, 13 solvent compositions at eutectic points and next to them, in addition to the reference solvent, TH:ME, are synthesized and applied for the solvent extraction of the aromatic aldehydes vanillin (VAN), syringaldehyde (SYR), and p-hydroxybenzaldehyde (HYD) from an acidic aqueous model solution. The extraction efficiency is determined from aldehyde concentrations measured by High-Performance Liquid Chromatography (HPLC), taking into consideration mutual solubility measured by Karl Fischer titration (KF) and a Total Organic Carbon-analysis (TOC). Physicochemical properties, such as the density, viscosity, and stability of the solvents, are evaluated and discussed. Additionally, 1H-NMR measurements are performed to verify hydrogen bonding present in some of the solvents. The results show that all synthesized eutectic systems have a strong hydrophobic character with a maximum water saturation of ≤2.21 vol.% and solvent losses of ≤0.12 vol.% per extraction step. The hydrophobic eutectic solvents based on CA exhibit lower viscosities, lower mutual solubility, and lower extraction efficiency for the aromatic aldehydes when compared with FE-based solvents. The highest extraction efficiencies for VAN (>95%) and for SYR (>93%) at an extraction efficiency of 92.61% for HYD are achieved by the reference solvent TH:ME (50:50 mol.%). With an extraction efficiency of 93.08%, HYD is most preferably extracted by the FE-DO-solvent (80:20 mol.%), where the extraction efficiencies for VAN and SYR reach their maximum at 93.37% and 90.75%, respectively. The drawbacks of the high viscosities of 34.741 mPas of the TH:ME solvent and 31.801 mPas of the FE-DO solvent can be overcome by the CA-TH solvent, which has a viscosity of 3.436 mPas, while exhibiting extraction efficiencies of 71.92% for HYD, >95% for VAN, and >93% for SYR, respectively.

Study of the volatile compounds of dry fermented sausage with salt reduction and its relationship with sensory acceptance

In many industrialised countries, sodium intake exceeds the nutritional guidelines. High sodium intake has been associated with health problems, such as arterial hypertension and, consequently, a higher health risk of cardiovascular disease. The aim of this study was to evaluate overall quality of salamis with reduced sodium content by analysing aldehydes, proteolysis, and lipolysis, as well as to verify the correlation between sensory acceptance and volatile compounds. Four formulations were prepared replacing NaCl by a mixture of KCI and CaCl2. Two controls, one with a high level and the other with a low NaCl level were also included in the study. Water activity and pH levels were monitored in all samples. Volatile compounds were measured, in particular, hexanal, 2,4-decadienal and 3-methylbutanal. Finally, a sensory acceptance test was carried out using potential consumers. The results highlighted a relation between aldehyde concentration and sensory acceptance, hexanal/3-methybutanal ratio, that may be a marker of partial NaCl substitution in salami. Thus, our results may be used to guide the use of NaCl substitution by KCl/CaCl2 in terms of volatile compounds.Graphical

Atmospheric aldehydes in indoor and outdoor environments impacted by combustion emissions of diesel/biodiesel mixtures

The temporal evolution of air pollutants concentrations inside a semi-closed bus station has been investigated since 2002 until 2023 to understand the impact of direct combustion emissions from buses using diesel/biodiesel fuel blends (B3-B12). Carbonyl compounds concentrations were evaluated, which predominance of acetaldehyde and formaldehyde. It is known that acrolein emission increases with the addition of biodiesel to diesel. However, the determination of acrolein by the official method is compromised due to coelution with acetone on liquid chromatographic separation. In this work, with adaptation of the mobile phase, acrolein was separated adequately and could be determinate in samples obtained in the same bus station while the vehicles had been using B12 fuel blends. Concomitantly, samples were collected outside the station to compare indoor and outdoor air quality. Formaldehyde, acetaldehyde and acrolein were detected in both environments. Aldehydes concentration was higher indoor than outdoors. There are indications that acrolein levels may increase with higher proportions of biodiesel in diesel blends. This study valuable information for future studies on air quality and vehicular emissions.