Carbon neutrality in wastewater treatment plants: An integrated biotechnological-based solution for nutrients recovery, odour abatement and CO2 conversion in alternative energy drivers.

Wastewater treatment plants play a crucial role in water security and sanitation, ensuring ecosystems balance and avoiding significant negative effects on humans and environment. However, they determine also negative pressures, including greenhouse gas and odourous emissions, which should be minimized to mitigate climate changes besides avoiding complaints. The research has been focused on the validation of an innovative integrated biological system for the sustainable treatment of complex gaseous emissions from wastewater treatment plants. The proposed system consists of a moving bed biofilm reactor coupled with an algal photobioreactor, with the dual objective of: i) reducing the inlet concentration of the odourous contaminants (in this case, hydrogen sulphide, toluene and p-xylene); ii) capturing and converting the carbon dioxide emissions produced by the degradation process into exploitable algal biomass. The first reactor promoted the degradation of chemical compounds up to 99.57% for an inlet load (IL) of 22.97 g m-3 d-1 while the second allowed the capture of the CO2 resulting from the degradation of gaseous compounds, with biofixation rate up to 81.55%. The absorbed CO2 was converted in valuable feedstocks, with a maximum algal biomass productivity in aPBR of 0.22 g L-1 d-1. Dairy wastewater has been used as alternative nutrient source for both reactors, with a view of reusing wastewater while cultivating biomass, framing the proposed technology in a context of a biorefinery within a circular economy perspective. The biomass produced in the algal photobioreactor was indeed characterized by a high lipid content, with a maximum percentage of lipids per dry weight biomass of 35%. The biomass can therefore be exploited for the production of alternative and clean energy carrier. The proposed biotechnology represents an effective tool for shifiting the conventional plants in carbon neutral platform for implementing principles of ecological transition while achieving high levels of environmental protection.

Multifaceted analysis of the effects of roasting conditions on the flavor of fragrant Camellia oleifera Abel. seed oil.

Fragrant Camellia oleifera Abel. seed oil (FCSO), produced by a roasting process, is popular for its characteristic aroma. This study investigated the effects of various roasting temperatures (90℃, 120℃, 150℃, 180℃) and durations (20 min, 40 min, 60 min) on the flavor of FCSO by physicochemical properties, hazardous substances, sensory evaluation, and flavor analyses. The results showed that FCSO roasted at 120℃/20 min had a reasonable fatty acid composition with a lower acid value (0.16 mg/g), peroxide value (0.13 g/100 g), p-anisidine value (2.27), dibutyl phthalate content (0.04 mg/kg), and higher 1,1-diphenyl-2-picrylhydrazyl free radical scavenging activity (224.51 µmol TE/kg) than other samples. A multivariate analysis of FCSO flavor revealed that the 120℃/20 min group had a higher grassy flavor score (5.3 score) from nonanoic acid and a lower off-flavor score (2.2 score) from 2-methylbutyric acid. The principal component analysis showed that 120℃/20 min could guarantee the best flavor and quality of FCSO. Therefore, this information can guide the preparation of FCSO.

The effect of maturity of tea leaves and processing methods on the formation of milky flavor in white tea - A metabolomic study.

Targeted metabolomics combined with chemometrics were applied to investigate the flavor profiles of 4 white tea samples, which were produced from different maturity fresh tea leaves with different withering methods. Mature leaves that underwent novel withering process at higher temperature (28-30℃) and humidity (75 ± 3 %) (MN) were characterized by intense milky flavor. The content of free amino acids, catechins, and soluble sugars in MN were significantly lower than that in the other 3 tea samples, resulting in a sweet and mellow taste with low bitterness. Meanwhile, MN possessed the highest intensity of milky aroma, which could be mainly attributed to the existence of dihydro-5-pentyl-2(3H)-furanone and 2-pentyl-furan as the key volatile substances with coconut and creamy fragrance. These findings provide insight into the substance foundations of milky flavor, and identified leaf maturity and processing method as the determining factors of the milk-flavored white tea (MFWT).

Combined multi-omics approach to analyze the flavor characteristics and formation mechanism of gabaron green tea.

Gabaron green tea (GAGT) has unique flavor and health benefits through the special anaerobic treatment. However, how this composite processing affects the aroma formation of GAGT and the regulatory mechanism was rarely reported. This study used nontargeted metabolomics and molecular sensory science to overlay screen differential metabolites and key aroma contributors. The potential regulatory mechanism of anaerobic treatment on the aroma formation of GAGT was investigated by transcriptomics and correlation analyses. Five volatiles: benzeneacetaldehyde, nonanal, geraniol, linalool, and linalool oxide III, were screened as target metabolites. Through the transcriptional-level differential genes screening and analysis, some CsERF transcription factors in the ethylene signaling pathway were proposed might participate the response to the anaerobic treatment. They might regulate the expression of related genes in the metabolic pathway of the target metabolites thus affecting the GAGT flavor. The findings of this study provide novel information on the flavor and its formation of GAGT.

Rapid classification of coffee origin by combining mass spectrometry analysis of coffee aroma with deep learning.

Mislabeling the geographical origin of coffee is a prevalent form of fraud. In this study, a rapid, nondestructive, and high-throughput method combining mass spectrometry (MS) analysis and intelligence algorithms to classify coffee origin was developed. Specifically, volatile compounds in coffee aroma were detected using self-aspiration corona discharge ionization mass spectrometry (SACDI-MS), and the acquired MS data were processed using a customized deep learning algorithm to perform origin authentication automatically. To facilitate high-throughput analysis, an air curtain sampling device was designed and coupled with SACDI-MS to prevent volatile mixing and signal overlap. An accuracy of 99.78% was achieved in the classification of coffee samples from six origins at a throughput of 1 s per sample. The proposed approach may be effective in preventing coffee fraud owing to its straightforward operation, rapidity, and high accuracy and thus benefit consumers.

Artificial Intelligence Sensing: Effective Flavor Blueprinting of Tea Infusions for a Quality Control Perspective.

Tea infusions are the most consumed beverages in the world after water; their pleasant yet peculiar flavor profile drives consumer choice and acceptance and becomes a fundamental benchmark for the industry. Any qualification method capable of objectifying the product's sensory features effectively supports industrial quality control laboratories in guaranteeing high sample throughputs even without human panel intervention. The current study presents an integrated analytical strategy acting as an Artificial Intelligence decision tool for black tea infusion aroma and taste blueprinting. Key markers validated by sensomics are accurately quantified in a wide dynamic range of concentrations. Thirteen key aromas are quantitatively assessed by standard addition with in-solution solid-phase microextraction sampling followed by GC-MS. On the other hand, nineteen key taste and quality markers are quantified by external standard calibration and LC-UV/DAD. The large dynamic range of concentration for sensory markers is reflected in the selection of seven high-quality teas from different geographical areas (Ceylon, Darjeeling Testa Valley and Castleton, Assam, Yunnan, Azores, and Kenya). The strategy as a sensomics-based expert system predicts teas' sensory features and acts as an AI smelling and taste machine suitable for quality controls.

Exploration of Raw Pigmented-Fleshed Sweet Potatoes Volatile Organic Compounds and the Precursors.

Sweet potato provides rich nutrients and bioactive substances for the human diet. In this study, the volatile organic compounds of five pigmented-fleshed sweet potato cultivars were determined, the characteristic aroma compounds were screened, and a correlation analysis was carried out with the aroma precursors. In total, 66 volatile organic compounds were identified. Terpenoids and aldehydes were the main volatile compounds, accounting for 59% and 17%, respectively. Fifteen compounds, including seven aldehydes, six terpenes, one furan, and phenol, were identified as key aromatic compounds for sweet potato using relative odor activity values (ROAVs) and contributed to flower, sweet, and fat flavors. The OR sample exhibited a significant presence of trans-ß-Ionone, while the Y sample showed high levels of benzaldehyde. Starch, soluble sugars, 20 amino acids, and 25 fatty acids were detected as volatile compounds precursors. Among them, total starch (57.2%), phenylalanine (126.82 ± 0.02 g/g), and fatty acids (6.45 µg/mg) were all most abundant in Y, and LY contained the most soluble sugar (14.65%). The results of the correlation analysis revealed the significant correlations were identified between seven carotenoids and trans-ß-Ionone, soluble sugar and nerol, two fatty acids and hexanal, phenylalanine and 10 fatty acids with benzaldehyde, respectively. In general, terpenoids and aldehydes were identified as the main key aromatic compounds in sweet potatoes, and carotenoids had more influence on the aroma of OR than other cultivars. Soluble sugars, amino acids, and fatty acids probably serve as important precursors for some key aroma compounds in sweet potatoes. These findings provide valuable insights for the formation of sweet potato aroma.

Testing detectability, attractivity, hedonic specificity, extractability, and robustness of colostrum odor-Toward an olfactory bioassay for human neonates.

Human milk odor is attractive and appetitive for human newborns. Here, we studied behavioral and heart-rate (HR) responses of 2-day-old neonates to the odor of human colostrum. To evaluate detection in two conditions of stimulus delivery, we first presented the odor of total colostrum against water. Second, the hedonic specificity of total colostrum odor was tested against vanilla odor. Third, we delivered only the fresh effluvium of colostrum separated from the colostrum matrix; the stability of this colostrum effluvium was then tested after deep congelation; finally, after sorptive extraction of fresh colostrum headspace, we assessed the activity of colostrum volatiles eluting from the gas chromatograph (GC). Regardless of the stimulus-delivery method, neonates displayed attraction reactions (HR decrease) as well as appetitive oral responses to the odor of total colostrum but not to vanilla odor. The effluvium separated from the fresh colostrum matrix remained appetitive but appeared labile under deep freezing. Finally, volatiles from fresh colostrum effluvium remained behaviorally active after GC elution, although at lower magnitude. In sum, fresh colostrum effluvium and its eluate elicited a consistent increase in newborns' oral activity (relative to water or vanilla), and they induced shallow HR decrease. Newborns' appetitive oral behavior was the most reproducible response criterion to the effluvium of colostrum. In conclusion, a set of unidentified volatile compounds from human colostrum is robust enough after extraction from the original matrix and chromatographic processing to continue eliciting appetitive responses in neonates, thus opening new directions to isolate and assay specific volatile molecules of colostrum.

Fermentation of Texturized Pea Protein in Combination with Proteases for Aroma Development in Meat Analogues.

The potential use of texturized pea protein in meat analogues was investigated by comparing the effects of fermentation on pea and myofibrillar pork proteins in a model system including additives, microbial starters, and proteases. Model fermentation was controlled for 15 days by a pH decrease and microbial count and free amino acid increase. Besides, volatile production and sensory properties were evaluated at the end of fermentation. Protein type affected free amino acid generation and volatile profile. Models supplemented with proteases showed an increase in amino-acid-derived compounds (branched aldehydes and alcohols) and fruity odor notes. During fermentation, protease addition significantly reduced the production of linear aldehydes (pentanal, hexanal, and octanal) in vegetal models, while pyrazine compounds were not affected. This changes in the volatile profile reduced the legume beany odor but increased the perception of toasted cereal-like notes generated by the texturization process.

Impact of dietary digestible aromatic amino acid levels and stachyose on growth, nutrient utilization, and cecal odorous compounds in broiler chickens.

This study evaluated the impact of dietary digestible aromatic amino acid (DAAA) levels and stachyose on growth, nutrient utilization and cecal odorous compounds in broiler chickens. A 3×2 two-factor factorial design: Three dietary DAAA levels (1.40, 1.54, 1.68%) supplemented with either 5 g/kg of stachyose or without any stachyose were used to create 6 experimental diets. Each diet was fed to 6 replicates of 10 birds from d 22 to 42. Findings revealed that broilers receiving a diet with 1.54% DAAA levels supplemented with 5 g/kg stachyose exhibited a significant boost in average daily gain and improved utilization of crude protein, ether extract, tryptophan, and methionine compared to other diet treatments (P < 0.05). As the dietary DAAA levels increased, there was a significant rise in the concentrations of indole, skatole, p-methylphenol, and butyric acid in the cecum of broilers (P < 0.05). The addition of stachyose to diets reduced concentrations of indole, skatole, phenol, p-methylphenol, acetic acid and propionic acid in the cecum (P < 0.05). The lowest concentrations of indole, phenol, p-methylphenol, volatile fatty acids and pH in cecum of broilers were observed in the treatment which diet DAAA level was 1.40% with stachyose (P < 0.05). In conclusion, dietary DAAA levels and stachyose had significant interactions on the growth, main nutrient utilization and cecal odorous compounds in broilers. The dietary DAAA level was 1.54% with 5 g/kg of stachyose can improve the growth performance, nutrient utilization. However, the dietary DAAA level was 1.40% with stachyose was more beneficial to decrease the cecal odor compound composition in broilers.

Impact of phenylalanine on Hanseniaspora vineae aroma metabolism during wine fermentation.

Hanseniaspora vineae exhibits extraordinary positive oenological characteristics contributing to the aroma and texture of wines, especially by its ability to produce great concentrations of benzenoid and phenylpropanoid compounds compared with conventional Saccharomyces yeasts. Consequently, in practice, sequential inoculation of H. vineae and Saccharomyces cerevisiae allows to improve the aromatic quality of wines. In this work, we evaluated the impact on wine aroma produced by increasing the concentration of phenylalanine, the main amino acid precursor of phenylpropanoids and benzenoids. Fermentations were carried out using a Chardonnay grape juice containing 150 mg N/L yeast assimilable nitrogen. Fermentations were performed adding 60 mg/L of phenylalanine without any supplementary addition to the juice. Musts were inoculated sequentially using three different H. vineae strains isolated from Uruguayan vineyards and, after 96 h, S. cerevisiae was inoculated to complete the process. At the end of the fermentation, wine aromas were analysed by both gas chromatography-mass spectrometry and sensory evaluation through a panel of experts. Aromas derived from aromatic amino acids were differentially produced depending on the treatments. Sensory analysis revealed more floral character and greater aromatic complexity when compared with control fermentations without phenylalanine added. Moreover, fermentations performed in synthetic must with pure H. vineae revealed that even tyrosine can be used in absence of phenylalanine, and phenylalanine is not used by this yeast for the synthesis of tyrosine derivatives.

Effects of Bacillus-based inoculum on odor emissions co-regulation, nutrient element transformations and microbial community tropological structures during chicken manure and sawdust composting.

This study aims to evaluate whether different doses of Bacillus-based inoculum inoculated in chicken manure and sawdust composting will provide distinct effects on the co-regulation of ammonia (NH3) and hydrogen sulfide (H2S), nutrient conversions and microbial topological structures. Results indicate that the Bacillus-based inoculum inhibits NH3 emissions mainly by regulating bacterial communities, while promotes H2S emissions by regulating both bacterial and fungal communities. The inoculum only has a little effect on total organic carbon (TOC) and inhibits total sulfur (TS) and total phosphorus (TP) accumulations. Low dose inoculation inhibits total potassium (TK) accumulation, while high dose inoculation promotes TK accumulation and the opposite is true for total nitrogen (TN). The inoculation slightly affects the bacterial compositions, significantly alters the fungal compositions and increases the microbial cooperation, thus influencing the compost substances transformations. The microbial communities promote ammonium nitrogen (NH4+-N), TN, available phosphorus (AP), total potassium (TK) and TS, but inhibit nitrate nitrogen (NO3--N), TP and TK. Additionally, the bacterial communities promote, while the fungal communities inhibit the nitrite nitrogen (NO2--N) production. The core bacterial and fungal genera regulate NH3 and H2S emissions through the secretions of metabolic enzymes and the promoting or inhibiting effects on NH3 and H2S emissions are always opposite. Hence, Bacillus-based inoculum cannot regulate the NH3 and H2S emissions simultaneously.

Release characteristics and risk assessment of volatile sulfur compounds in a municipal wastewater treatment plant with odor collection device.

Due to the malodorous effects and health risks of volatile sulfur compounds (VSCs) emitted from wastewater treatment plants (WWTPs), odor collection devices have been extensively utilized; however, their effectiveness has rarely been tested. In the present investigation, the characteristics of VSCs released in a WWTP equipped with gas collection hoods are methodically examined by gas chromatography. The obtained results indicate that the concentration of VSCs in the ambient air can be substantially reduced, and the primary treatment unit still achieves the highest concentration of VSCs. Compared to WWTPs without odor collection devices, the concentration of H2S in this WWTP is not dominant, but its sensory effects and health risks are still not negligible. Additionally, research on the emission of VSCs from sludge reveals that the total VSCs emitted from dewatering sludge reaches the highest level. Volatile organic sulfur compounds play a dominant role in the component and sensory effects of VSCs released by sludge. This study provides both data and theoretical support for analyzing the effectiveness of odor collection devices in WWTPs, as well as reducing the source of VSCs. The findings can be effectively employed to optimize these devices and improve their performance.

Exploring aromatic components differences and composition regularity of 5 kinds of these 4 aroma types Phoenix Dancong tea based on GC-MS.

Different aromatic components do indeed give different tea flavors. There is still little research on whether there is a certain regularity in the combination and content of aromatic components in different aroma types of Phoenix Dancong (PDC) tea. This potential regularity may be a key factor in unraveling the relationship between reproduction and evolution in PDC tea. Here, the 5 kinds of these 4 aroma types PDC tea (Zhuye, Tuofu, Jianghuaxiang, Juduo, Yashixiang) were used as research materials in this study, the headspace solid-phase microextraction combined with gas chromatography-mass spectrometry was used to analyze the aromatic components of these PDC teas. The results showed a total of 36 aromatic components identified in this study. When conducting cluster analysis, it was found that similarity degree arrangement sequence of 5 PDC teas was Juduo, Tuofu, Yashixiang, Zhuye and Jianghuaxiang. Among these aromatic components, the 7,9-Di-tert-butyl-1-oxaspiro(4,5)deca-6,9-diene-2,8-dione, the 2-Cyclopenten-1-one, 3-methyl-2-(2-pentenyl)-,(Z)-, the 2,4-Di-tert-butylphenol, the 3,7-dimethyl-1,5,7-Octatrien-3-ol, and the 2-Furanmethanol,5-ethenyltetrahydro-.alpha.,.alpha.,5-trimethyl-,cis- are common to 5 PDC teas. This study aims to elucidate the similarities in the aromatic components of 5 PDC teas, revealing the major aroma-endowed substances of various aroma, and providing theoretical reference for further exploring the relationship between aroma type discrimination, variety selection, and evolution of PDC teas.

Neural mechanisms of odour imagery induced by non-figurative visual cues.

Odour imagery, the ability to experience smell when an appropriate stimulus is absent, has widely been documented as being particularly difficult. However, previous studies have shown the beneficial effect of visual cues (e.g., pictures or words) to facilitate performance in numerous tasks of olfactory nature. Therefore, the use of visual cues to evoke odours seems relevant. In this study, our interest is directed towards non-figurative coloured arrangements, which result from a patented technology and aim at chromatically representing any smell from its chemical composition and sensory description. The aim of this study was to characterise the neural mechanisms of odour imagery facilitated by these non-figurative coloured arrangements. Using functional magnetic resonance imaging, we recorded and compared hemodynamic responses during odour imagery facilitated by non-figurative coloured arrangements and pictures. Our findings reveal that the use of non-figurative coloured arrangements during odour imagery solicits olfactory and non-olfactory brain regions (orbitofrontal cortex, insula, hippocampus, thalamus, dorsolateral prefrontal cortex and supplementary motor area), which are mainly involved in olfactory processing and multimodal integration. Moreover, very similar cortical activity was found between the use of non-figurative coloured arrangements and pictures during odour imagery, with increased activity in the supplementary motor area during the use of coloured arrangements only. Overall, non-figurative coloured arrangements could become a robust tool to visually evoke odours without requiring prior familiarity with the depicted odour. Future studies should use psychometric measures to determine the relationships between brain activation, odour imagery ability and vividness of the generated odour images.

Therapeutic Management of Malignant Wounds: An Update.

OPINION STATEMENT: Malignant fungating wounds (MFW) are severe skin conditions generating tremendous distress in oncological patients with advanced cancer stages because of pain, malodor, exudation, pruritus, inflammation, edema, and bleeding. The classical therapeutic approaches such as surgery, opioids, antimicrobials, and application of different wound dressings are failing in handling pain, odor, and infection control, thus urgently requiring the development of alternative strategies. The aim of this review was to provide an update on the current therapeutic strategies and the perspectives on developing novel alternatives for better malignant wound management. The last decade screened literature evidenced an increasing interest in developing natural treatment alternatives based on beehive, plant extracts, pure vegetal compounds, and bacteriocins. Promising therapeutics can also be envisaged by involving nanotechnology due to either intrinsic biological activities or drug delivery properties of nanomaterials. Despite recent progress in the field of malignant wound care, the literature is still mainly based on in vitro and in vivo studies on small animal models, while the case reports and clinical trials (less than 10 and only one providing public results) remain scarce. Some innovative treatment approaches are used in clinical practice without prior extensive testing in fungating wound patients. Extensive research is urgently needed to fill this knowledge gap and translate the identified promising therapeutic approaches to more advanced testing stages toward creating multidimensional wound care strategies.

Evaluation of spontaneous fermentation impact on the physicochemical properties and sensory profile of green and roasted arabica coffee by digital technologies.

There is a growing demand for specialty coffee with more pleasant and uniform sensory perception. Wet fermentation could modulate and confer additional aroma notes to final roasted coffee brew. This study aimed to assess differences in volatile compounds and the intensities of sensory descriptors between unfermented and spontaneously fermented coffee using digital technologies. Fermented (F) and unfermented (UF) coffee samples, harvested from two Australia local farms Mountain Top Estate (T) and Kahawa Estate (K), with four roasting levels (green, light-, medium-, and dark-) were analysed using near-infrared spectrometry (NIR), and a low-cost electronic nose (e-nose) along with some ground truth measurements such as headspace/gas chromatography-mass spectrometry (HS-SPME-GC-MS), and quantitative descriptive analysis (QDA ®). Regression machine learning (ML) modelling based on artificial neural networks (ANN) was conducted to predict volatile aromatic compounds and intensity of sensory descriptors using NIR and e-nose data as inputs. Green fermented coffee had significant perception of hay aroma and flavor. Roasted fermented coffee had higher intensities of coffee liquid color, crema height and color, aftertaste, aroma and flavor of dark chocolate and roasted, and butter flavor (p < 0.05). According to GC-MS detection, volatile aromatic compounds, including methylpyrazine, 2-ethyl-5-methylpyrazine, and 2-ethyl-6-methylpyrazine, were observed to discriminate fermented and unfermented roasted coffee. The four ML models developed using the NIR absorbance values and e-nose measurements as inputs were highly accurate in predicting (i) the peak area of volatile aromatic compounds (Model 1, R = 0.98; Model 3, R = 0.87) and (ii) intensities of sensory descriptors (Model 2 and Model 4; R = 0.91), respectively. The proposed efficient, reliable, and affordable method may potentially be used in the coffee industry and smallholders in the differentiation and development of specialty coffee, as well as in process monitoring and sensory quality assurance.

Effects of Monascus purpureus on ripe Pu-erh tea in different fermentation methods and identification of characteristic volatile compounds.

The present study aimed to explore the key volatile compounds (VCs) that lead to the formation of characteristic flavors in ripe Pu-erh tea (RIPT) fermented by Monascus purpureus (M. purpureus). Headspace solid-phase microextraction coupled with gas chromatography/mass spectrometry (HS-SPME-GC-MS), orthogonal partial least square-discriminant analysis (OPLS-DA) were employed for a comprehensive analysis of the VCs present in RIPT fermented via different methods and were further identified by odor activity value (OAV). The VCs 1,2-dimethoxybenzene, 1,2,3-trimethoxybenzene, (E)-linalool oxide (pyranoid), methyl salicylate, linalool, ß-ionone, ß-damascenone were the key characteristic VCs of RIPT fermented by M. purpureus. OAV and Gas chromatography-olfactometry (GC-O) further indicated that ß-damascenone was the highest contribution VCs to the characteristic flavor of RIPT fermented by M. purpureus. This study reveals the specificities and contributions of VCs present in RIPT under different fermentation methods, thus providing new insights into the influence of microorganisms on RIPT flavor.

Aroma and taste analysis of pickled tea from spontaneous and yeast-enhanced fermentation by mass spectrometry and sensory evaluation.

Anaerobically fermented pickled tea (PT) can be produced by spontaneous fermentation (SF) or yeast-enhanced fermentation (YF). Aroma and taste characteristics of PT during YF and SF were investigated using sensory evaluation, odour activity, aroma character impact values, HS-SPME-GC-MS, UPLC-QQQ-MS/MS, and spectrophotometry, annotating 198 volatile and 115 non-volatile components. The main contributing volatile components were ß-ionone, and 1-octanol, promoted by YF and SF, and yielding floral and fruity aromas respectively. Additionally, compared with SF, YF promoted the formation of citronellol yielding a floral aroma, inhibited the stale aroma of methoxybenzenes, and reduced bitter, astringent, and sour tastes. Furthermore, partial least-squares regression analysis identified the main components related to the 'acides aroma' of PT as linalool oxide, n-decanoic acid, hexanoic acid, 3,7-dimethyl-2,6-octadienoic acid, 3-methyl-1-dodecyn-3-ol, and nerolidol. This application could be used as methodology for the comprehensive analysis of tea aroma and taste and these results can act as guidelines for PT production and quality control.

Effect of industrial wastewater treatment system upgrade on the composition of emitted odorants and volatile organic compounds from a cheese production facility.

This study investigates the rarely studied volatile organic compound emissions from a cheese production facility and the impact of its wastewater treatment system upgrade on the composition of emitted odorants. Wastewater grab samples were collected from six separate wastewater channels before (2019) and after (2021) the system upgrade and analyzed for volatile organic compounds, pH, total dissolved solids, and electrical conductivity. Results showed that the channel from hard cheese production in 2021 had the highest number of volatile organic compounds (35), followed by the fresh cheese production channel (22). Following the industrial wastewater treatment system upgrade, a mineral oil contamination occurred; however, the number of odorants with nasal impact frequency (NIF) ≥ 0.5 in the effluent decreased from 11 to 5. 2-Propenoic acid butyl ester (NIF 0.75) stood out as the most prominent compound, described as fruity, waxy, or green. After the industrial wastewater treatment system upgrades, we observed a decrease in the number of odorants. However other measures must be taken to ensure proper wastewater processing. PRACTITIONER POINTS: More than 60 VOCs were identified in 6 channels from the cheese production facility.15 odorants in cheese production wastewater were detected by SPME-GC-MS/O. The most potent odorants before and after the system upgrade were 1-octen-3-ol and 2-propenoic acid butyl ester, respectively. The upgrades of the industrial wastewater treatment system had a positive impact on reducing the number of odorants and their odor intensity.