Odorous Compounds Research Articles

Biofiltration for odor mitigation in water resource recovery facilities.

Odor emissions, primarily from anthropogenic activities like waste treatment and industrial processes, pose significant challenges in urban areas, particularly near water resource recovery facilities. While these emissions are generally not toxic, they can adversely affect community wellbeing and investment, prompting stricter regulations in some regions. For example, New York State's hydrogen sulfide guidelines are more stringent than federal standards. Hydrogen sulfide, along with other reduced sulfur compounds, volatile organic compounds, and nitrogen compounds, are among the key odorants produced by water resource recovery facilities. Various methods have been explored to mitigate these odors, including chemical treatments, operational modifications, and air treatment strategies like biofiltration, activated carbon adsorption, and regenerative incineration. Among these, biofiltration stands out as an environmentally friendly option due to its high efficiency in removing hydrogen sulfide and other odorants without the need for chemicals. Biofiltration systems, including biofilters and biotrickling filters, use microorganisms immobilized in a bed of porous media to degrade odorous compounds. Biofilters, which operate with intermittent water supply, are highly effective at total odor removal. In contrast, biotrickling filters, which use continuous nutrient and water flow, are better suited for higher pollutant loads but struggle with compounds of low solubility. Key factors influencing biofilter performance include the empty bed residence time, media type, moisture content, and microbial diversity. This review explores recent advancements in biofilter technology, with a focus on the removal of hydrogen sulfide and organic sulfur compounds. It also highlights real-world applications in water resource recovery facilities and discusses critical design and operational parameters for improving odor control, such as media selection, residence time, pH regulation, and microbial management. Key studies underscore the importance of media composition and nutrient supply in optimizing biofilter performance, especially at higher pollutant concentrations. Understanding these factors will help inform future improvements in odor management for water resource recovery facilities.

Biochemical, micro and ultrastructural changes in vanilla pods (Vanilla planifolia, Andrews) during the curing process

Vanilla is used in several industries, due to during the artisanal curing process, compounds responsible for a highly demanded aroma are synthesized. This process involves physical, biochemical, microbiological and structural changes, which through their study with high-resolution techniques allowed for deep introspection at the ultra-structural level, to identify cellular structures. Which, under conditions leading to the pod during the process, allow the synthesis, release, and storage of molecules aroma responsible. The integration of the referred changes will allow the strategies generation that lead to better use of the vanilla extract and its residue obtained after the extraction processes (∼95%) to which the sheath could be subjected. The proximal chemical analysis showed an increase in lipids (∼25%) at 10 SS (drying-sweating cycles) associated with oleoresins and aroma responsible compounds. Proteins increased (∼50%), a result of the catalytic activity of the enzymes present and associated with the endophytic flora. β-glucosidase associated with the synthesis of aromatic compounds, increased their activity at 10 SS (196 IU/mL). The mesocarp showed a folding and shrinkage of (∼50%), evaluated by SEM and image analysis. Using CLSM, the major compounds in the bean were located and their relationship with the micro and ultra-structure. Using TEM, plastoglobules responsible for the odorant compounds accumulation and plasmodesmata for their transport and storage were identified. The comprehensive study of the curing process and the phenomena conjunction involved, allowed the process key stage identification, important for the proposal of strategies that lead to the optimal use of the metabolites and their residues.

Characterization of three novel dimethyl disulfide degrading bacteria and their potential degradation pathways.

Dimethyl disulfide (DMDS) is an odor compound characterized by the lowest olfactory threshold and high toxicity. It is indispensable to explore the bacteria with high resistance and degradation efficiency to DMDS. Acinetobacter lwoffii, Pseudomonas mendocina, and Myroides odoratus were isolated from kitchen waste. After 6days of individual treatment, the removal rates were 34.22%, 40.95%, and 41.94% respectively. The DMDS metabolic pathways based on metagenomic assays were discovered to be incomplete due to the insufficient annotation of some key genes in the current database. Following 3days of treatment with bacterial consortia at ratios of 5:1 for A. lwoffii C2/ M. odoratus C7 and 1:1:1 for the three strains achieved 100% DMDS removal. Additionally, the consortia reduced hydrogen sulfide (H2S) and dimethyl sulfide (DMS).This discovery broadens the spectrum of bacteria exhibiting high tolerance and efficient degradation of DMDS, with significant implications for DMDS removal and odor treatment.

Development of estrus detection technology for breeding female of Japanese black cows using odor compounds from vaginal secretions

Development of estrus detection technology for breeding female of Japanese black cows using odor compounds from vaginal secretions

The Impact of Storage Conditions on Stool Smellprints as Assessed by an Electronic Nose.

Necrotizing enterocolitis (NEC) is a devastating disease of the neonatal gastrointestinal tract. Volatile organic compounds (VOCs), odoriferous compounds released as a byproduct of bacterial metabolism, can be used as a proxy for gut health. We hypothesized that patients with NEC would have different microbial profiles and elicit different VOC signatures as assessed by gas chromatography/mass spectrometry (GC/MS) or an electronic nose compared to controls. Furthermore, we hypothesized that the temperature of sample storage and the length of time in storage would impact the VOC signatures. Forty-five human stool samples were obtained from Neonatal Intensive Care Units. They were stored at -80 °C as part of the Necrotizing Enterocolitis Biorepository. The microbiome composition was determined by 16S-rRNA gene sequencing and VOC profiles were obtained with GC-MS and by analysis with the Cyranose 320 electronic nose. In separate experiments, fresh stool samples were collected from three different strains of mice. Samples were stored for different times and different temperatures, and VOC signals were compared. A p-value less than 0.05 was considered significant. 16S-rRNA sequencing found a difference in the microbiome composition (p = 0.025) between human NEC and control samples. There was also a difference observed between NEC and control samples identified by GC-MS (p = 0.001). However, there were no differences in VOC smellprints between NEC and controls when analyzed with an electronic nose. When mouse specimens were analyzed, principal component values changed significantly over time and with different storage temperatures. NEC is associated with a different gut microbiome and the VOC profile compared to age-matched controls. However, this difference was not appreciated when biobanked stool samples were compared via an electronic nose. Older samples may experience VOC decay, or the electronic nose may not be sensitive enough to detect NEC in stool samples. Further studies on fresh human stool samples are needed, but the findings herein may limit the use of electronic noses as diagnostic tools for NEC.

Characterization of the ligand-binding properties of odorant-binding protein 38 from Riptortus pedestris when interacting with soybean volatiles.

Riptortus pedestris (Fabricius) (Hemiptera: Alydidae) is a major soybean pest throughout East Asia that relies on its advanced olfactory system for the perception of plant-derived volatile compounds and aggregation pheromones for conspecific and host plant localization. Odorant binding proteins (OBPs) facilitate the transport of odorant compounds across the sensillum lymph within the insect olfactory system, enabling their interaction with odorant receptors (ORs). Real-time quantitative PCR (qRT-PCR) analyses, fluorescence-based competitive binding assays, and molecular docking analyses were applied to assess the expression and ligand-binding properties of OBP38 from R. peddestris. The qRT-PCR analyses revealed high levels of RpedOBP38 expression in the antennae without any apparent sex bias, and it was also highly expressed in the adult stage. Recombinant RpedOBP38 was prepared by expressing it in E. coli BL21 (DE3) followed by its purification with a Ni-chelating affinity column. RpedOBP38 was found to bind most strongly to trans-2-decenal (Ki = 7.440) and trans-2-nonenal (Ki = 10.973), followed by β-pinene, (+) -4-terpineol, carvacrol, methyl salicylate, and (-)-carvone. The 3D structure of RpedOBP38 contains six α-helices and three interlocked disulfide bridges comprising a stable hydrophobic binding pocket. In a final series of molecular docking analyses, several polar (e.g., His 94, Glu97) and nonpolar (e.g., Leu29, Ile59) residues were found to be involved in RpedOBP38-ligand binding. These data support a role for RpedOBP38 in the perception of volatiles derived from host plants, providing important insight into the mechanisms that govern olfactory recognition in R. pedestris, thereby informing the development of ecologically friendly approaches to managing R. pedestris infestations.

High Antennal Expression of CYP6K1 and CYP4V2 Participate in the Recognition of Alarm Pheromones by Solenopsis invicta Buren.

Insects have highly developed olfactory systems in which cytochrome P450s (CYPs) were involved as odor-degrading enzymes throughout the olfactory recognition of odor compounds by insects to avoid continuous stimulation of signaling molecules and thus damage to the olfactory nervous. To understand whether the highly expressed CYPs in the antennae play an olfactory function in Solenopsis invicta worker, in this study, we find six highly expressed antennal CYPs from the transcriptome of S. invicta. Multiple sequence alignment and phylogenetic analysis divided them into two families: the CYP3 family (SinvCYP6K1, SinvCYP6K1-1) and the CYP4 family (SinvCYP4C1, SinvCYP4C1-1, SinvCYP4C1-2, SinvCYP4V2). The expression patterns of these six CYPs were analyzed by RT-qPCR, which revealed that SinvCYP6K1 and SinvCYP4V2 were only highly expressed in the antennae of adult workers. The expression of SinvCYP6K1 and SinvCYP4V2 in workers was markedly diminished after feeding with dsRNA. The electroantennography (EAG) assay demonstrated that the silencing of either SinvCYP6K1 or SinvCYP4V2 resulted in a notable reduction in the EAG response of workers to 2-ethyl-3,6(5)-dimethylpyrazine (EDMP). Furthermore, the trajectory behavior assay showed that the worker's range and speed of movement in response to EDMP significant decreased after the silencing of SinvCYP6K1 and SinvCYP4V2. The findings indicated that both SinvCYP6K1 and SinvCYP4V2 were implicated in the recognition of EDMP by S. invicta.

Design, simulation, and manufacturing of analyzer optical cell for detection and measurement of injectable odorant at pressure reduction stations.

The absence of a mercaptan compounds analyzer in natural gas pressure reduction stations (PRS) odorizer leads to inaccuracies in the injection dosage, often resulting in quantities beyond standard limits and consequently increasing odorant consumption. Insufficient odorant levels in natural gas can pose safety risks to consumers, as the gas may become odorless at the end of the pipeline. Therefore, accurate determination of the concentration of key odorant compounds in natural gas can reduce both costs and environmental risks. In this study, a hybrid UV-IR analyzer for detecting key odorant compounds was designed and developed. Initially, regional conditions were examined, and various natural gas and odorant samples were analyzed to identify compound percentages, which were then used to prepare calibration gas cylinders. Based on the results of simulated conditions, the analyzer's structure was designed, and technical specifications of components were determined. The analyzer consists of mechanical and optoelectronic units, connected via fiber optics. Subsequently, an optical cell was designed and manufactured, and the performance of the analyzer's components was evaluated in laboratory testing systems. This device can measure two key compounds, tert-butyl mercaptan and isopropyl mercaptan, separately, simultaneously, or in mixtures, making it comparable to an online gas chromatograph (GC). Installing this analyzer in PRSs enables precise adjustment of odorant injection dosages based on the analyzer's real-time results.

Effects of Temporary Rearing on the Muscle Flavor Quality of Chinemys reevesii.

Chinemys reevesii, a special economic aquaculture species in China, is valued highly for its medicinal and nutritional benefits. However, the muscle of farmed C. reevesii exhibits a strong off-flavor, resulting in poor flavor quality. To enhance the flavor quality of the C. reevesii meat, this study examined the volatile compounds in C. reevesii muscle by establishing identification methods for these volatile odor compounds and comparing the differences between the two aquaculture modes. It also explored the impact of fasting temporary rearing (60 days) on the flavor quality of the C. reevesii meat. The results indicated that a combination of direct solvent extraction-solvent-assisted flavor evaporation (DSE-SAFE), headspace-solid phase microextraction (HS-SPME), gas chromatography-mass spectrometry/olfactometry (GC-MS/O), and aroma recombination effectively simulated the odor profile of C. reevesii meat. The study identified the key volatile odor compounds in outdoor pond-cultivated C. reevesii meat (OP), including hexanal, heptanal, 1-octen-3-ol, octanal, nonanal, (E)-2-nonenal, decanal, (E)-2-decenal, (E,E)-2,4-decadienal, and dodecanal. In greenhouse-cultivated C. reevesii meat (GH), key volatile odor compounds were hexanal, hexanol, heptanal, 1-octen-3-ol, octanal, nonanal, (E)-2-nonenal, decanal, (E)-2-decenal, and dodecanal. The study found that appropriate fasting temporary rearing improved the odor quality of C. reevesii meat; OP temporary rearing for 40-50 days showed a significant reduction in greasy and musty odors. In GH, 40 days temporary rearing retained a fresh aroma while reducing the seaweed and fishy odors, achieving a flavor similar to OP. This study provides data support for C. reevesii meat processing and suggests a reference for applying temporary rearing to enhance the flavor quality of aquatic products.

Optimization of Odorous Compounds Analysis in Water Using Headspace-SPME and GC-MSD, and Detection Characteristics in the Nakdong River Basin

Objectives : This study developed a simple and automated analytical method using headspace-SPME (solid phase microextraction) and GC (gas chromatography)-MSD (mass selective detector) to simultaneously analyze ten odorous compounds (dimethyl trisulfide (DMTS), 3-hexenylacetate (HA), 2-isopropyl-3-methoxypyrazine (IPMP), 2-methylbenzofuran (MBF), 2-isobutyl-3-methoxypyrazine (IBMP), β-cyclocitral (CC), trans-2-decenal (DCNL), 2-trans-4-trans-decadienal (DENL) 2,4,6-trichloroanisole (TCA) 및 β-ionone (ION)), evaluating their distribution characteristics throughout the Nakdong River basin.Methods : To optimize the extraction efficiency of the headspace-SPME method for ten odorous compounds, we evaluated various SPME fiber materials, extraction temperatures, extraction times, desorption temperatures, desorption times and salt (NaCl) dosages. Additionally, using the optimized headspace-SPME, we investigated the detection concentrations at ten main stream sites and six tributary sites in the Nakdong River basin.Results and Discussion : The most suitable SPME fiber material for the pretreatment of ten odorous compounds was CAR/PDMS/DVB. The optimal SPME extraction temperature and time were 75°C and 60 minutes, respectively, and the optimal desorption temperature and time at the GC injection port were 250°C and 3 minutes. Additionally, the optimal salt (NaCl) dosage for a 10 mL water sample was 2 g. Using the optimized headspace-SPME pretreatment method for GC-MSD analysis, the detection limits and quantification limits for the ten odorous compounds ranged from 2 to 10 ng/L and 5 to 25 ng/L, respectively, with HA exhibiting the highest detection and quantification limits. The evaluation of the distribution characteristics of odorous compounds throughout the Nakdong River basin revealed that only three compounds—DMTS, CC and ION—were detected. Among these, DMTS was found at the highest concentration of 115.5 ng/L in the tributary Jincheon-cheon, while CC was detected at the highest concentration of 30.6 ng/L in the main river at Goryeong. In the case of the Nakdong River basin, there was no contamination by odorous compounds in the upstream area. In the middle reach, influenced by effluent of wastewater treatment plants, the detection concentrations of three odorous compounds increased, but they showed a decreasing trend as they moved downstream.Conclusion : Since odorous compounds can lead to distrust in water quality even at extremely low concentrations in the ng/L range in tap water, regular monitoring of water sources is necessary during algal bloom season, including the dry season. Furthermore, continuous research is needed on various odorous compounds beyond the 10 odorous compounds in this study, including the optimization of analytical methods and the detection characteristics in water sources.

Geosmin Events Associated with Dolichospermum circinale Abundance Promoted by Nitrogen Supply in a Chinese Large Tropical Eutrophic Reservoir.

Taste and odor (T/O) compounds are a global threat in drinking water, mainly produced by cyanobacteria in freshwater environments. Temperature plays a crucial role in regulating geosmin dynamics in temperate and subtropical lakes, while its influence may be lower in tropical waters. To better understand the factors affecting geosmin occurrence in tropical waters, a dataset from a field investigation conducted in a large tropical reservoir was analyzed. The water temperature varied between 16 °C and 32 °C, with geosmin concentration ranging from below the detection limit (3 ng/L) to as high as 856 ng/L. Elevated geosmin levels exceeding > 10 ng/L were observed over the whole year except for in September, suggesting that the annual temperature was suitable for geosmin production. Among the diverse cyanobacteria, Dolichospermum circinale was identified as the main producer of geosmin in the reservoir, both by correlation analysis and cells' geosmin measurements. Geosmin concentration was also significantly related to the abundance of D. circinale. None of the environmental variables (temperature, pH, transparency and nutrients) were significantly directly correlated with geosmin concentration. But the high total nitrogen significantly explained the increase in D. circinale abundance associated with geosmin elevation. Our results suggest that nutrients, particularly nitrogen, directly affected the competitive advantage and abundance of key geosmin producers and thus modified geosmin levels in this tropical reservoir. Our study thus hints at the possible management of the geosmin problem through nutrient reduction in tropical reservoirs.

Effects of benzoic acid in pig diets on nitrogen utilization, urinary pH, slurry pH, and odorous compounds.

The objective was to investigate the effects of dietary benzoic acid (BA) on nitrogen (N) balance, urinary pH, slurry pH, and odorous compounds in feces and slurry of pigs. Twelve barrows with an initial body weight of 56.2±2.6 kg were individually housed in metabolism crates. The animals were allocated to a replicated 6×4 incomplete Latin square design with 12 animals, 6 experimental diets, and 4 periods, resulting in 8 observations per treatment. The basal diet consisted mainly of corn, soybean meal, and rapeseed meal. Benzoic acid was supplemented to the basal diet at 0.5%, 1.0%, 1.5%, 2.0%, or 2.5% at the expense of corn starch. Each period consisted of a 4-day adaptation period and a 24-h collection period for slurry, followed by a 4-day collection period for feces and urine. On day 5, feces and urine were collected for 24 h and mixed to obtain slurry samples. The daily digested N linearly increased (p<0.05) with increasing BA supplementation. Supplemental BA lowered urinary pH (p<0.001) and slurry pH (p<0.05) in a linear and quadratic manner. In the fecal samples, the concentrations of acetate, propionate, butyrate, and skatole linearly decreased (p<0.05) with supplemental BA. In the slurry samples, the concentrations of butyrate, isovalerate, and skatole linearly decreased (p<0.05) by supplemental BA. In conclusion, supplemental benzoic acid has the potential to improve nitrogen digestion in a dose-dependent manner for pigs. Additionally, dietary benzoic acid lowers urinary pH, slurry pH, and concentrations of odorous compounds in pig feces and slurry.

Characterization of key off-odor compounds in grass carp cube formed during room temperature storage by molecular sensory science approach

Flavor is a significant factor in determining the popularity of freshwater fish. However, freshwater fish can easily spoil during storage, producing an unpleasant odor. Little research has determined the changes in key off-odor compounds (OOCs) in freshwater fish during storage. In this study, quantitation and odor activity value (OAV) calculations revealed that 19 odorants were important volatile odor compounds in fresh, spoilage, and serious spoilage GCC. Recombination and omission experiments verified that (E)-2-hexenal, acetoin, N,N-dimethyl-benzenamine, trimethylamine (TMA), and ammonia were the key OOCs in spoilage GCC. Additional key OOCs in serious spoilage GCC were cyclohexane isothiocyanato, butylated hydroxytoluene, putrescine, cadaverine and histamine compared to those of spoilage GCC. Correlation analysis showed that 12 amino acids and 10 fatty acids played important roles in the formation of key OOCs. This study provides a theoretical basis for a comprehensive understanding of the formation of key OOCs in GCC during room temperature storage.

Biodegradation-assisted removal of sulfur-based odor compounds in rural drinking water using durable chitosan/polyvinyl alcohol biochar aerogels

Rural drinking water often suffers from unpleasant odors like dimethyl sulfide (DMDS) and dimethyl trisulfide (DMTS) due to poor raw water quality and limited treatment options. This study introduces durable chitosan/polyvinyl alcohol (PVA) biochar aerogels-supported bioflims in ultrafiltration (BAB-UF) reactors, where the incorporation of PVA significantly enhances structural integrity, biodegradation resistance, and functional lifespan, providing an efficient, sustainable solution for removing odorous compounds from rural water. Experimental results showed the enhanced chitosan/PVA porous biochar aerogels (CPPCA) displayed excellent biocapacity and structural stability. After 63 days of continuous operation, the degradation rate of biochar aerogels with 0.2 wt% PVA (CP2PCA) was only 8.2 %. The one-step membrane reactors utilizing PVA-enhanced aerogels achieved removal efficiencies for DMDS/DMTS pollutants of up to 98.4 %, surpassing systems without PVA. These findings indicate the potential for improved aerogels in rural drinking water treatment, providing a viable solution for effective and low-maintenance water purification.

Preparation of Low-Fishy Microencapsulated DHA-Rich Algal Oil Powder Using Infant Rice Powder.

Commercial DHA-rich algal oil has some issues, such as an unpleasant odor and susceptibility to oxidation. The main fishy odor compounds in commercial DHA-rich algal oil powder and DHA-rich algal oil microcapsules are hexanal and (E, E)-2,4-heptadienal. To address this issue, a microencapsulation process was designed for DHA-rich algal oil using infant rice powder (IRP), maltodextrin (MD), and whey protein concentrate (WPC) as wall materials, with sodium starch octenyl succinate (SSOS) and monoacylglycerol (MAC) as emulsifiers. The spray-drying method was used for microencapsulation. The experimental data showed that microcapsules with wall materials in a ratio of IRP/MD/WPC = 1:3:1 and an emulsifier content of 3.5% (SSOS and MAC) had the highest encapsulation efficiency (85.20 ± 6.03%) and the lowest aldehyde content (65.38 ± 3.23%). This microcapsule showed a good appearance and better oxidation stability compared with the crude oil, with a water content and average particle size of 1.69 ± 0.57% and 631.60 ± 23.19 nm, respectively. The results indicated that DHA-rich algal oil microcapsules prepared with infant rice powder had a lower fishy odor and better sensory acceptability compared to commercial DHA-rich algal oil powder.

Identification of odor compounds from Wagyu cattle feed “fermented TMR” for quality assessment and efficient analysis by ultra-compact portable gas chromatography

Identification of odor compounds from Wagyu cattle feed “fermented TMR” for quality assessment and efficient analysis by ultra-compact portable gas chromatography

Effects of amino acids on the release of acidic odor compounds in Langjiu and its potential mechanisms

Non-volatile amino acids could influence the overall aroma volatility and perception of Chinese liquor (Baijiu), yet the underlying mechanisms remain unclear. In this study, stir bar sorptive extraction-gas chromatography-mass spectrometry (SBSE-GC-MS) and amino acid analyzer were used to identify the odor compounds and free amino acids in Langjiu. Six acidic odor compounds with an odor activity value (OAV) ≥ 1 and the flavor amino acid L-phenylalanine (L-phe) were selected for analysis. Partition coefficient and olfactory threshold analyses were conducted to investigate the effect of L-phe on the release of these odor compounds. The results indicated that L-phe promoted the release of 3-methylbutanoic acid and pentanoic acid, while it inhibited the release of 2-methylpropanoic acid, butanoic acid, hexanoic acid, and octanoic acid. However, at high concentrations (257 mg/L), L-phe attenuated both the promotive and inhibitory effects. Fluorescence spectroscopy and isothermal titration calorimetry analyses demonstrated that the six acidic odor compounds effectively quenched the intrinsic fluorescence of L-phe through a static quenching mechanism, forming ground-state complexes. The primary interactions between L-phe and 3-methylbutanoic acid and pentanoic acid were attributed to hydrophobic interactions, while the interactions with 2-methylpropanoic acid, butanoic acid, hexanoic acid, and octanoic acid were mainly due to electrostatic interactions. This study provides new insights into the flavor regulation of Baijiu.

Chemical mimicry in the corpse flower: Floral odor and phytochemical profiles of Amorphophallus titanum (Becc.) Becc.

Amorphophallus titanum (Becc.) Becc., commonly known as titan arum, corpse flower or carrion flower, is famous for having the largest inflorescence in the world. In addition to mimicking rotting meat with its flesh-colored floral parts and thermogenesis features, the bloom produces a variety of odorous chemical compounds that give the inflorescence its characteristic rotting animal smell when blooming, in order to attract a specific group of pollinators. This study analyses the volatile chemical profiles of the odors emitted during various stages of blooming. The floral odor samples were collected at different times of the bloom using HS-SPME fibers, and the samples were analyzed by GC/Q-ToF. A total of 66 volatile compounds were identified in the bloom, representing 31.62–96.92% of the volatile composition. Several malodorous compounds were detected, including trimethylamine, dimethyl disulfide, dimethyl trisulfide, dimethyl tetrasulfide, and indole. We also analyzed the non-volatile phytochemical constituents of various floral and vegetative organs of the plant for the first time using LC/Q-ToF and identified 40 compounds, including flavonoids, anthocyanins, amino acids, xanthones, C-glycosylflavones, and organic acids in different organs of the plant. The main constituents of anthocyanins were cyanidin-3-O-glucoside and cyanidin-3-O-rutinoside. Leucine, isoleucine, phenylalanine, tryptophan, and methionine were the major amino acids found in the plant's organs. We observed that A. titanum emits distinct odor compounds from different parts of the inflorescence at various stages of blooming.

Biological effects of Maillard reaction products: use of Caenorhabditis elegans as an in vivo model.

Maillard reaction products (MRPs), including melanoidins and volatile odor compounds, are associated with distinct flavors and colors during food processing and cooking. Although MRPs have health benefits, such as antioxidant activity, they are also associated with pathophysiological effects. Several in vivo models, especially rodents, are used to demonstrate physiological effects. Caenorhabditis elegans (C. elegans), an easy to rear free-living nematode with a short lifespan, has been used as a promising in vivo organism for the evaluation of functional properties in food components, including anti-aging, antioxidant, and anti-obesity properties. Furthermore, the high olfactory discrimination of this organism allows for the basic elucidation of behavior and regulation of aging. In this Minireview, I discuss the various attributes of C. elegans that make it a promising in vivo model for studying the biological effects of MRPs.

Novel Insights into the Enrichment Pattern of Aroma and Taste in Cooked Marinated Meat Products of Black Pork via Typical Process Steps.

This study aims to reveal the evolution mechanism of odour and taste active compounds in cooked marinated pork knuckles via typical process steps; among them, the brine soup stage was the most important part due to spices' enriching flavours. These results revealed that the content and diversity of volatile compounds increased due to the addition of spices and heating temperature, imparting a unique aroma. Aldehydes played the main role in the overall odour. Benzaldehyde, hexanal, 1-octen-3-ol, levulinic acid, hydroxyacetone, ethyl octanoate, and 2-pentyl-furan were identified as the most important odour-active compounds. The key taste-active amino acids were glutamine, leucine, valine, and lysine. The IMP, AMP, and GMP provided a strong umami taste. Taste nucleotides and Val, Leu, Ile, and Phe were important precursor substances for aldehydes. The high responses of the electronic nose indicated that the gas component contained alkanes, alcohols, and aldehydes. The synergistic effects between umami-free amino acids and nucleotides correlated well with umami, as assessed by the electronic tongue. These results could be a starting point for the manufacturing industry, contributing to a better understanding of product performance.