Off-flavors are a major challenge for companies using recirculated aquaculture systems (RAS). In the presented work, we comprehensively characterize the odorant composition of Nile tilapia (Oreochromis niloticus) raised in RAS and compare the impact of two depuration processes on the odorant composition and aroma profile of the fish. Fish collected from the production tank and after two different tank pre-disinfection approaches in the depuration process (high pH versus H2O2) were investigated. A combined sensory-instrumental investigation revealed the presence of 115 odorants, of which 83 were successfully identified. The compounds decanal, tridecanal, (Z)-1,5-octadien-3-one, octane-2,3-dione, benzophenone, non-3-yn-1-ol, γ-dodecalactone, (Z)-geranylacetone, 2,3-diethyl-5-methylpyrazine, 1-methylpyrrolidin-2-one, 2-acetyl-2-thiazoline, benzothiazole, skatole, and 5α-androst-16-en-3-one were detected with the highest flavor dilution factors and are described for the first time as odor-active compounds in fish from RAS. The results indicate that depuration decreased the levels of 78 different odorants from the fish, including the potent earthy smelling odorants geosmin, isoborneol and 2,3-diethyl-5-methylpyrazine.

We examined the possibility of a cross-modal effect in naïve Cotesia vestalis, a parasitoid wasp of diamondback moth larvae, by using artificial flower models of four colours (blue, green, yellow, and red) in the absence or presence of floral scent collected from Brassica rapa inflorescences. In a four-choice test, regardless of the floral scent, non-starved female wasps visited green and yellow models significantly more often than blue and red ones, although no significant difference was observed between visits to the green and yellow models. They seldom visited blue and red models. When starved, the wasps became even more particular, visiting yellow significantly more frequently than green models, irrespective of the presence of the floral scent, indicating that they preferred to use yellow visual cues in their food search. Furthermore, a factorial analysis of variance revealed a significant effect of the interaction between model colour and floral scent on the wasps\' visits to flower models. The floral scent induced starved and non-starved wasps to visit yellow and green models about twice as often as without the scent. A cross-modal effect of olfactory perception on the use of chromatic information by wasps may allow them to search efficiently for food sources.

The prevalence of posttraumatic olfactory dysfunction in children after mild traumatic brain injury ranges from 3 to 58%, with potential factors influencing this variation, including traumatic brain injury severity and assessment methods. This prospective longitudinal study examines the association between mild traumatic brain injury and olfactory dysfunction in children. Seventy-five pediatric patients with mild traumatic brain injury and an age-matched healthy control group were enrolled. Olfactory function was assessed using the Sniffin\' Sticks battery, which focuses on olfactory threshold and odor identification. The study found that children with mild traumatic brain injury had impaired olfactory function compared with healthy controls, particularly in olfactory threshold scores. The prevalence of olfactory dysfunction in the patient group was 33% and persisted for 1 yr. No significant association was found between traumatic brain injury symptoms (e.g. amnesia, loss of consciousness) and olfactory dysfunction. The study highlights the importance of assessing olfactory function in children after mild traumatic brain injury, given its potential impact on daily life. Although most olfactory dysfunction appears transient, long-term follow-up is essential to fully understand the recovery process. The findings add valuable insights to the limited literature on this topic and urge the inclusion of olfactory assessments in the management of pediatric mild traumatic brain injury.

Nitrogen fertilizer supports agricultural intensification, but its manufacturing results in substantial contaminated sites. Ammonia nitrogen is the main specific pollutant in retired nitrogen fertilizer sites with potential human health and odor risks. However, few studies focus on ammonia nitrogen risk assessment at contaminated sites, particularly considering its solid-liquid partitioning process (Kd) and ammonium/ammonia equilibrium process (R) in the soil. This study took a closed nitrogen fertilizer factory site as an example and innovatively introduced Kd and R to scientifically assess the human health and odor risk of ammonia nitrogen. The risk control values (RCVs) of ammonia nitrogen based on human health and odor risk were also derived. The maximum concentration of ammonia nitrogen was 3380 mg/kg in the unsaturated soil, which was acceptable for human health because the health RCVs were 5589 ∼ 137,471 mg/kg in various scenarios. However, odor risk was unacceptable for RCVs were 296 ∼ 1111 mg/kg under excavation scenarios and 1118 ∼ 35,979 mg/kg under non-excavation scenarios. Of particular concern, introducing Kd and R in calculation increased the human health and odor RCVs by up to 27.92 times. Despite the advancements in ammonia risk assessment due to the introduction of Kd and R, odor risk during excavation remains a vital issue. These findings inform a more scientific assessment of soil ammonia risk at contaminated sites and provide valuable insights for the management and redevelopment of abandoned nitrogen fertilizer plant sites.

Serving temperature plays a crucial role in influencing the sensory experience of consumers. In this context, this study investigated the influence of serving temperature on the aroma release and perception of a typical fermented alcoholic beverage named Huangjiu. A quantitative sensory description analysis was conducted, determining serving temperature significantly influenced the 17 sensory attributes in both semi-dry and semi-sweet Huangjiu. The variation in the contents of 41 volatiles in the Huangjiu with temperature was investigated using gas chromatography-ion mobility spectrometry, resulting in volatile content significantly increasing above 30 ℃. The partial least squares discriminant analysis was conducted to predict the variable importance for the projection (VIP) of volatiles, and 22 volatiles (VIP > 1) were screened. These 22 volatiles were confirmed as key odorants influenced by serving temperature though aroma addition experiments. The findings would provide a reference for the effects of serving temperature on the flavor perception of fermented alcoholic beverages.

Contamination by odor substances such as geosmin (GSM) and 2-methylisoborneol (2-MIB) was examined in the cultured water from aquaculture farming in the region of the Hongze Lake in 2022, and some factors influencing residual levels of them in the water were analyzed. Geographically, high concentrations of GSM were located mainly in the north and northeast culture areas of the lake, while those of 2-MIB were found in the northeast and southwest. Analysis of the water in the enclosure culture revealed significant differences in the concentrations of GSM and 2-MIB among the cultured species. The mean concentrations of GSM in culture water were ranked in the order: crab > the four major Chinese carps > silver and bighead carp, and silver and bighead carp > crab > the four major Chinese carps for 2-MIB. The concentration of GSM was significantly higher at 38.99 ± 18.93 ng/L in crab culture water compared to other fish culture water. Significant differences were observed in GSM concentrations between crab enclosure culture and pond culture, while 2-MIB levels were comparable. These findings suggest that cultural management practices significantly affect the generation of odor substances. The taste and odor (T&O) assessment revealed that the residual levels of GSM and 2-MIB in most samples were below the odor threshold concentrations (OTCs), although high levels of GSM and 2-MIB in all water bodies were at 30.9% and 27.5%, respectively. Compared with the corresponding data from other places and the regulation guidelines of Japan, USA, and China, the region in the Hongze Lake is generally classified as a slightly T&O area, capable of supporting the aquaculture production scale.

Currently, soil odor-active substance screening and evaluation methods for contaminated sites are underdeveloped, with unclear treatment objectives and areas. Consequently, some sites suffer from odor issues during and even after remediation. This study focused on an organophosphorus pesticide factory site in Guangdong Province, China. It established a method of determining the odorant control area using a comprehensive approach combining instrumental and olfactory soil sample analyses. The main odor-active substances identified were ethylbenzene, phenol, m, p-xylene, styrene, toluene, and o-xylene, with odorant control values (the limit of odor-active substance contents) of 35.2, 28.1, 8.0, 11.3, 40.2 and 89.3 mg/kg respectively. Instrumental analysis of soil samples revealed 11 sampling points where the main odor-causing substances exceeded standard levels. Among the substances, ethylbenzene (1.48E+04 mg/kg) had the highest content, exceeding the limit up to 421-fold. Olfactory analysis indicated 14 sampling points with odor intensity surpassing the standard (OI > 2). Based on the instrumental analysis results and the odorant control value, the initial estimated odor control area (area with the risk of odor nuisance) was 5.64E+03 m2. Incorporating the olfactory analysis findings, the control area was adjusted by 1.25E+03 m2, leading to a final calculated soil odor control area of 6.89E+03 m2 for the study site. The comprehensive approach to analyzing soil samples for odor control can help evaluate the extent of soil odor pollution in contaminated sites and provide a scientific basis for effectively removing and managing odor-causing substances in soil.

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Surveys and assessments of contaminated sites primarily focus on hazardous pollutants in the soil with less attention paid to odorants. This makes the management of contaminated sites difficult. In this study, hazardous and odorous pollutants in the soil were assessed for a large site that was previously used for production of pharmaceuticals to determine the degree and characteristics of soil contamination at pharmaceutical production sites, for undertaking rational remediation measures. The main hazardous pollutants at the study site were triethylamine, n-butyric acid, benzo(a)pyrene (BaP), N-nitrosodimethylamine (NDMA), dibenzo(a,h)anthracene (DBA), total petroleum hydrocarbons (C10-C40) (TPH), and 1,2-dichloroethane; TEA, BA, and isovaleric acid (IC) were the main odorants. As the type and distribution of hazardous and odorous pollutants differ, it is necessary to separately assess the impact of these pollutants at a contaminated site. Soils in the surface layer pose significant non-carcinogenic (HI = 68.30) and carcinogenic risks (RT = 3.56E-5), whereas those in the lower layer only pose non-carcinogenic risks (HI > 7.43). Odorants were found at considerable concentrations both in the surface and lower layers, with the maximum concentrations being 29,309.91 and 41.27, respectively. The findings of this study should improve our understanding of soil contamination at former pharmaceutical production sites and should inform the assessment of the risks posed by contaminated sites, with problems associated with odour, and possible remediation strategies.

The aged Chinese liquor, Baijiu, is highly valued for its superior organoleptic qualities. However, since age-authentication method and aging-mechanism elucidation of Baijiu is still in the exploratory stage, high-quality aged Baijiu is often replaced by lower-quality, less-aged product with fraudulent mislabeling. Authentic high-quality strong-flavor Baijiu was analyzed by gas chromatography-mass spectrometry. Total esters decreased with aging, while acids, alcohols, aldehydes, ketones, terpenes, pyrazines increased. Although concentrations of partial compounds showed non-monotonic profiling during aging, a close positive linear correlation (R2 = 0.7012) of Baijiu Evenness index (0.55-0.59) with aging time was observed, indicating a more balanced composition in aged Baijiu. The reaction quotient (Qc) of each esterification, calculated by the corresponding reactant and product concentration, approached to the corresponding thermodynamic equilibrium constant Kc. This result demonstrated that the spontaneous transformation driven by thermodynamics explained part of the aging compositional profiling. Furthermore, an aging-related feature selection and an age-authentication method were established based on three models combined with five ranking algorithms. Forty-one key features, including thirty-six compound concentrations, four esterification Qc values and the Evenness index were selected out. The age-authentication based on neural network using forty-one input features accurately predicted the age group of Baijiu samples (F1 = 100 %). These findings have deepened understanding of the Baijiu aging mechanism and provided a novel, effective approach for age-authentication of Baijiu and other liquors.