The aroma transformation of Japanese sea bass (Lateolabrax japonicas) through endogenous enzyme incubation during the lag phase of attached microorganisms.

Endogenous enzymes play a crucial role in determining fish product aroma. However, the attached microorganisms can promote enzyme production, making it challenging to identify specific aromatic compounds resulting from endogenous enzymes. Thus, we investigated the aroma transformation of Japanese sea bass through enzymatic incubation by controlling attached microorganisms during the lag phase. Our results demonstrate that enzymatic incubation significantly enhances grassy and sweet notes while reducing fishy odors. These changes in aroma are associated with increased levels of 10 volatile compounds and decreased levels of 3 volatile compounds. Among them, previous studies have reported enzyme reaction pathways for octanal, 1-nonanal, vanillin, indole, linalool, geraniol, citral, and 6-methyl-5-hepten-2-one; however, the enzymatic reaction pathways for germacrene D, beta-caryophyllene, pristane, 1-tetradecene and trans-beta-ocimene remain unclear. These findings provide novel insights for further study to elucidate the impact of endogenous enzymes on fish product aromas.

Easily injectable gelatin-nonanal hydrogel for endoscopic resectioning of gastrointestinal polyps.

The use of submucosal injection is crucial for satisfactory submucosal elevation in the early resection of flat polyps originating from the gastrointestinal tract (GIT). Injectable hydrogels derived from natural polypeptides are attractive candidates due to their excellent biocompatibility and easy gelation properties. However, most of the reported hydrogels are not the class of catheter delivery materials due to quick gelation, high inherent viscosity, and injection clogging. This study presents a novel injectable shear-thinning hydrogel platform of small molecules (nonanal) modified gelatin polymer, which offers a promising submucosal injection for effective removal of polyps from GIT. Physicochemical characterizations of hydrogel demonstrate the suitable features as an effective submucosal injection, including shear thinning property, self-assembly, methylene blue dye encapsulation, flow behavior, stability, syringeability (18 G, 21 G, and 24 G needles) and fibrous morphology. Ex vivo investigations of developed submucosal formulation on goat intestines demonstrate the enhanced visibility of cushions and the ability to produce stable, long-lasting cushions of about 8.07 mm up to ∼60 min of submucosal injection. The rapid blood clotting behavior of hydrogel was observed in about 120 s without compromising hemocompatibility with the hemolysis of about 3.77 % only. In vitro biocompatibility of the hydrogel was also verified using the HepG2 and nHDF cells. In vivo study depicts desirable biocompatibility, a non-toxic organ profile, and optimal cushion height in mice models. Studies established the foundation of novel submucosal fluid to improve the therapeutic outcomes of early resection for gastrointestinal polyps.

Verification and Evaluation of Male-Produced Pheromone Components from the Citrus Long-Horned Beetle, Anoplophora chinensis (Forster) (Insecta: Coleoptera: Cerambycidae).

The citrus long-horned beetle, Anoplophora chinensis (Coleoptera: Cerambycidae), is a highly polyphagous species native to eastern and southeastern Asia. Detection of these beetles is dependent on visual surveys, which are inefficient and labor-intensive. The identification and development of pheromone-based lures would help improve survey efforts for A. chinensis should it become established within the US. We identified three antennally active male-produced chemical components (nonanal, 4-(n-heptyloxy)butan-1-ol, and 4-(n-heptyloxy)butanal), which were then tested for behavioral activity at our USDA Quarantine laboratory. When tested together in Y-tube behavioral assays, a three-component blend of the identified compounds was shown to be attractive to adult female A. chinensis. Pheromone production and behavior of A. chinensis and other closely related Anoplophora cerambycid species are discussed in relation to mate finding and potential monitoring.

Ethnobotany, phytochemistry, pharmacology and quality control of Peucedanum decursivum (Miq.) Maxim: A critical review.

ETHNOPHARMACOLOGICAL RELEVANCE: Dried roots of Peucedanum decursivum, a traditional Chinese medicine (TCM), has historically respiratory diseases such as cough, thick phlegm, headache, fever, and gynecological diseases, rheumatoid arthritis, and nasopharyngeal carcinoma. AIM OF THE STUDY: Made an endeavor to evaluate the research trajectory of P. decursivum, comprehensively discern its developmental status, and offer a guideline for future investigations. MATERIALS AND METHODS: A meticulous search of literatures and books from 1955 to 2024 via databases like PubMed, Web of Science and CNKI was conducted, including topics and keywords of " P. decursivum" "Angelica decursivum" and "Zihua Qianhu". RESULTS: P. decursivum and its prescriptions have traditionally been used for treating phlegm-heat cough, wind-heat cough, gastrointestinal diseases, pain relief and so on. It contains 234 identified compounds, encompassing coumarins, terpenes, volatile oils, phenolic acids, fatty acids and derivatives. It exhibits diverse pharmacological activities, including anti-asthmatic, anti-inflammatory, antioxidant effects, anti-hypertensive, anti-diabetic, anti-Alzheimer, and anti-cancer properties, primarily attributed to coumarins. Microscopic identification, HPLC fingerprinting, and bioinformatics identification are the primary methods currently used for the quality control. CONCLUSION: P. decursivum demonstrates anti-asthmatic, anti-inflammatory, and antioxidant effects, aligning with its traditional use. However, experimental validation of its efficacy against phlegm and viruses is needed. Additionally, analgesic effects mentioned in historical texts lack modern pharmacological studies. Numerous isolated compounds exhibit highly valuable medicinal properties. Future research can delve into exploring these substances further. Rigorous of heavy metal contamination, particularly Cd and Pb, is necessary. Simultaneously, investigating its pharmacokinetics and toxicity in humans is crucial for the safety.

Synergistic antifungal mechanism of cinnamaldehyde and nonanal against Aspergillus flavus and its application in food preservation.

Aspergillus flavus colonization on agricultural products during preharvest and postharvest results in tremendous economic losses. Inspired by the synergistic antifungal effects of essential oils, the aims of this study were to explore the mechanism of combined cinnamaldehyde and nonanal (SCAN) against A. flavus and to evaluate the antifungal activity of SCAN loading into diatomite (DM). Shriveled mycelia were observed by scanning electron microscopy, especially in the SCAN treatment group. Calcofluor white staining, transmission electron microscopy, dichloro-dihydro-fluorescein diacetate staining and the inhibition of key enzymes in tricarboxylic acid cycle indicated that the antifungal mechanism of SCAN against A. flavus was related to the cell wall damage, reactive oxygen species accumulation and energy metabolism interruption. RNA sequencing revealed that some genes involved in antioxidation were upregulated, whereas genes responsible for cell wall biosynthesis, oxidative stress, cell cycle and spore development were significantly downregulated, supporting the occurrence of cellular apoptosis. In addition, compared with the control group, conidia production in 1.5 mg/mL DM/cinnamaldehyde, DM/nonanal and DM/SCAN groups were decreased by 27.16%, 48.22% and 76.66%, respectively, and the aflatoxin B1 (AFB1) contents decreased by 2.00%, 73.02% and 84.15%, respectively. These finding suggest that DM/SCAN complex has potential uses in food preservation.

Paeonia mascula subsp. russoi (biv.) Cullen & Heywood: the chemical composition of the aerial parts essential oils of two different populations collected in Sicily (Italy).

In the present study, the chemical composition of the essential oil from aerial parts of two populations of Paeonia mascula subsp. russoi, collected in Sicily, was evaluated by GC-MS. No previously phytochemical investigation has been reported for this subspecies. The main components of the essential oil of the population with pink flowers were salicylaldehyde (34.31%), nonanal (16.95%) and 2-hexenal (10.17%), whereas essential oil of the population with white flowers, was shown to be rich of myrtanal (14.14%), eugenol (14.02%) and salicylaldehyde (12.21%). Furthermore, a complete literature review, not present in literature, on the composition of the essential oils of all the other taxa of Paeonia, studied so far, was performed. PCA and HCA analyses of the composition of essential oils obtained from the aerial parts were also carried out.

Microcapsules of mesoporous silica and cyclodextrin modified loaded with nonanal and decanal for effective control of Sitotroga cerealella in grain storage environments.

BACKGROUND: The Angoumois grain moth, Sitotroga cerealella, is a destructive pest of maize, wheat, and rice, causing economic losses and threatening food security. This study aimed to develop and characterize microcapsules of mesoporous silica nanospheres (MSN) and cyclodextrin-modified mesoporous silica nanospheres (CDMSN) containing two aldehydes, nonanal and decanal, found in plant essential oils, to assess their attractiveness to S. cerealella populations. RESULTS: Microcapsules with 2:1 ratio of nonanal and decanal exhibited an average encapsulation efficiency of 39.82% for MSN loaded with nonanal and decanal (MSN-ND) and 46.10% for CDMSN loaded with nonanal and decanal (CDMSN-ND). They have an elliptical shape with particle sizes of 115 nm for MSN and 175 nm for CDMSN. Gas chromatography-mass spectrometry analysis revealed in vitro release of nonanal in MSN at 96.24% and decanal at 96.42% by the 36th day. CDMSN showed releases of 93.83% for nonanal and 93.74% for decanal by the 50th day. CDMSN-ND attracted adult S. cerealella for 43 days, while MSN-ND remained effective for 29 days. In mass trapping assays in simulated grain warehouse, both MSN-ND and CDMSN-ND trapped over 50% of the adult population within 7 days, significantly reducing grain infestation rates below 10% by inhibiting F1 adult emergence. At temperatures ranging from 20 °C to 35 °C, both microcapsules exhibited significant and effective attraction rates for S. cerealella. Stored wheat seeds treated with CDMSN and CDMSN-ND over 1 year showed no significant differences in key germination parameters. CONCLUSION: Microencapsulated nonanal and decanal offer a promising, sustainable approach for controlling S. cerealella infestation in stored grains, contributing to global food security. © 2024 Society of Chemical Industry.

Bamboo shoots improve the nutritional and sensory quality, and change flavor composition of chicken soup.

The effect of adding bamboo shoots to stewing on the quality and flavor of chicken soup has never been reported. Therefore, this study investigated the effects of 4 kinds of bamboo shoots on the edible quality, volatile and water-soluble flavor components of Chahua chicken soup. The results showed that adding bamboo shoots changed the sensory and nutritional quality of chicken soup. A total of 62 volatile flavor components were identified by HS-SPME-GC-MS, of which 12 were identified as characteristic volatile flavor components, and 9 were the main reasons for the flavor differences between bamboo shoot chicken soup with blank chicken soup. LC-MS found that after adding bamboo shoots, the differential water-soluble components in chicken soup significantly increased, and most of the increased components have been proven to have physiological functional activity. In conclusion, adding bamboo shoots improved the nutritional and sensory quality, and changed the flavor components of chicken soup.

Effect of different isolation sources of Lactococcus lactis subsp. lactis on volatile metabolites in fermented milk.

Lactococcus lactis subsp. lactis (L. lactis subsp. lactis) is a commonly used starter cultures in fermented dairy products, contributing distinct flavor and texture characteristics with high application value. However, the strains from different isolates have different contributions to milk fermentation. Therefore, this study aimed to investigate the influence of L. lactis subsp. lactis isolated from various sources on the volatile metabolites present in fermented milk. In this study, L. lactis subsp. lactis from different isolation sources (yogurt, koumiss and goat yogurt) was utilized as a starter culture for fermentation. The volatile metabolites of fermented milk were subsequently analyzed by headspace solid phase microextraction gas chromatography-mass spectrography (HS-SPME-GC-MS). The results indicated significant differences in the structure and abundance of volatile metabolites in fermented milk produced with different isolates (R2Y = 0.96, Q2 = 0.88). Notably, the strains isolated from goat yogurt appeared to enhance the accumulation of ketones (goat yogurt vs yogurt milk: 50 %; goat yogur vs koumiss: 27.3 %)and aldehydes (goat yogurt vs yogurt milk: 21.4 %; goat yogurt vs koumiss: 54.5 %) in fermented milk than strains isolated from koumiss and yogurt milk. It significantly promoted the production of 8 flavor substances (1 substance with OAV ≥ 1 and 6 substances with OAV > 0.1) and enhanced the biosynthesis of valine, leucine, and isoleucine. This study provides valuable insights for the application of Lactococcus lactis subsp. lactis isolated from different sources in fermented dairy production and screening of potential starter cultures.

Comparative key aroma compounds and sensory correlations of aromatic coconut water varieties: Insights from GC × GC-O-TOF-MS, E-nose, and sensory analysis.

Aroma is a key criterion in evaluating aromatic coconut water. A comparison regarding key aroma compounds and sensory correlations was made between Thailand Aromatic Green Dwarf (THD) and Cocos nucifera L. cv. Wenye No. 4 coconut water using E-nose and GC × GC-O-TOF-MS combined with chemometrics. Twenty-one volatile components of coconut water were identified by GC × GC-O-TOF-MS, and 5 key aroma compounds were analyzed by relative odor activity value and aroma extract dilution analysis. Moreover, the combination of the E-nose with orthogonal partial least squares was highly effective in discriminating between the two coconut water samples and screened the key sensors responsible for this differentiation. Additionally, the correlation between volatile compounds and sensory properties was established using partial least squares. The key aroma compounds of coconut water exhibited positive correlations with the corresponding sensory properties.

Cell-free reduction of carboxylic acids with secreted carboxylic acid reductase.

Mycobacterium marinum CAR (MmCAR) is one of the most widely used CARs as the key enzyme for the synthesis of aldehydes, alcohols and further products from the respective carboxylic acids. Herein, we describe the first functionally secreted 131 kDa CAR and its isolated A-domain using Komagataella phaffii and a methanol-free constitutive expression strategy. Precipitated and lyophilized MmCAR (500 µg) was isolated from the culture supernatant and showed no decrease in activity for piperonylic acid (80% conversion), even when stored for up to 3 weeks at 4°C. Lyophilized MmCAR precipitate gave 48% yield of E/Z-nonanal-4-nitrobenzoyloxime from the reduction of nonanoic acid and in-situ derivatization with O-4-nitrobenzoyl-hydroxylamine. Furthermore, K. phaffii could successfully secrete the MmCAR adenylation domain. Its activity was confirmed by the amidation of benzoic acid with n-hexylamine. Neither enzyme variant was glycosylated by the yeast. In summary, functional CAR can be secreted by K. phaffii and used for cell free conversion of carboxylic acids to various products.

Influence of electrohydrodynamics on the drying characteristics and volatile components of iron stick yam.

The drying characteristics, rehydration capacity, color, infrared spectra and volatile components of iron stick yam slices were investigated under different alternating current (AC) voltages (13, 17, 21 kV), hot air drying (HAD) (60 °C) and natural drying (AD) by electrohydrodynamic (EHD) drying and HAD experimental devices. The results showed that slices of iron stick yam dried the quickest with HAD, which also had the fastest drying rate; while drying the slices of iron stick yam with EHD led to a better rehydration capacity, higher brightness L* and whiteness, a more stable protein secondary structure, and a greater variety and content of volatile components compared with AD and HAD. These finding indicated that EHD is a more promising method for drying iron stick yam.

The chemical composition of the aerial parts' essential oil of Cynoglossum clandestinum Desf. growing in Sicily, Italy.

Cynoglossum L. is a taxonomically difficult genus belonging to the Boraginaceae family, distributed in Asia, Europe, mainly in Turkey, and in the Mediterranean region. Plants of this genus are used against various diseases in the ethnomedicine of several countries. In the present study, the chemical composition of the essential oil was obtained from the hydrodistillation of aerial parts of the Sicilian accession of Cynoglossum clandestinum Desf. was analysed by GC and GC-MS. The main constituents of the essential oil were aldehydes and ketones (69.9%) with nonanal (18.9%), 4-sec-butoxy-2-butanone (18.1%), and 3-methyl-butanal (13.1%) as main metabolites. No one paper has been previously published on the essential oil of this species, and there is a lack of studies also in the near related genera. The aim of this work is in fact, to study a species that has never been investigated, and through this, try to help place it within the Boraginaceae family.

Dynamic changes to the plant cuticle include the production of volatile cuticular wax-derived compounds.

The cuticle is a hydrophobic structure that seals plant aerial surfaces from the surrounding environment. To better understand how cuticular wax composition changes over development, we conducted an untargeted screen of leaf surface lipids from black cottonwood (Populus trichocarpa). We observed major shifts to the lipid profile across development, from a phenolic and terpene-dominated profile in young leaves to an aliphatic wax-dominated profile in mature leaves. Contrary to the general pattern, levels of aliphatic cis-9-alkenes decreased in older leaves following their accumulation. A thorough examination revealed that the decrease in cis-9-alkenes was accompanied by a concomitant increase in aldehydes, one of them being the volatile compound nonanal. By applying exogenous alkenes to P. trichocarpa leaves, we show that unsaturated waxes in the cuticle undergo spontaneous oxidative cleavage to generate aldehydes and that this process occurs similarly in other alkene-accumulating systems such as balsam poplar (Populus balsamifera) leaves and corn (Zea mays) silk. Moreover, we show that the production of cuticular wax-derived compounds can be extended to other wax components. In bread wheat (Triticum aestivum), 9-hydroxy-14,16-hentriacontanedione likely decomposes to generate 2-heptadecanone and 7-octyloxepan-2-one (a caprolactone). These findings highlight an unusual route to the production of plant volatiles that are structurally encoded within cuticular wax precursors. These processes could play a role in modulating ecological interactions and open the possibility for engineering bioactive volatile compounds into plant waxes.

Conserved Odorant Receptors Involved in Nonanal-Induced Female Attractive Behavior in Two Spodoptera Species.

Moths rely on plant volatiles to locate appropriate plants for feeding and laying eggs. While extensive research has been conducted on the global agricultural pests, Spodoptera frugiperda and Spodoptera litura, their molecular mechanisms for detecting plant volatiles remain mostly unknown. Here, we have demonstrated that nonanal, a common plant volatile, is attractive for both virgin and gravid females of the two species. Second, we have identified a conserved odorant receptor clade (SfruOR47 clade) that is primarily tuned to nonanal. Finally, by three-dimensional (3D) structure prediction, molecular docking, and site-directed mutagenesis, we have revealed that the His57 and Glu61 residues, also shared by other six orthologous ORs, are essential for nonanal binding in SfruOR47 and SlituOR9, indicating the conserved structure and function of ORs in the SfruOR47 clade. These findings offer novel insights into the molecular mechanisms and evolutionary aspects of moth behavior in response to plant volatiles.

Synergistic effects of combined cinnamaldehyde and nonanal vapors against Aspergillus flavus.

This study evaluated the synergistic antifungal effects of vapor-phase natural agents against Aspergillus flavus with an aim to prevent fungal contamination in agricultural products. Screening different combinations of natural antifungal vapor agents using the checkerboard assay revealed that the cinnamaldehyde and nonanal (SCAN) blend could exert the strongest synergistic antifungal activities against A. flavus, with a minimum inhibitory concentration (MIC) of 0.03 µL/mL, which caused a 76 % decrease in fungal population compared to when each agent was used separately. Subsequent gas chromatography-mass spectrometry (GC/MS) analysis demonstrated that the cinnamaldehyde/nonanal combination was stable and no effects on their individual molecular structures. SCAN at 2 × MIC completely inhibited the fungal conidia production and mycelial growth. The calcofluor white (CFW) and dichloro-dihydro-fluorescein diacetate (DCFH-DA) staining assays showed that SCAN treatment could accelerate the destruction of cell wall integrity and accumulation of reactive oxygen species (ROS) in A. flavus. Moreover, pathogenicity assay indicated that in contrast to separate treatment with cinnamaldehyde or nonanal, SCAN could cause a decrease in the production of A. flavus asexual spores and AFB1 on peanuts, which verified its potential synergistic activity against fungal propagation. In addition, SCAN effectively preserves the organoleptic and nutritional properties of stored peanuts. Overall, our findings strongly indicated that the cinnamaldehyde/nonanal combination is a potentially significant antifungal agent against A. flavus contamination during the postharvest storage of peanuts.

Characterization of the key odor-active compounds in different aroma types of Fu brick tea using HS-SPME/GC-MSO combined with sensory-directed flavor analysis.

Fu brick tea (FBT) is popular for its unique 'fungal flower' aroma, however, its key odor-active compounds are essentially unknown. In this study, the odor-active compounds of "stale-fungal" aroma (CJX), "fresh-fungal" aroma (QJX), and "fermentation-fungal" aroma (FJX) types FBT were extracted and examined by headspace solid phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) and gas chromatographyolfactometry (GC-O). A total of 43 volatile and 38 odor-active compounds were identified by these methods. Among them, the content of dihydroactindiolide (4596-13189 µg/L), (E)-linalool oxide (2863-6627 µg/L), and benzyl alcohol (4992-6859 µg/L) were highest. Aroma recombination experiments further verified that these odor-active compounds could be simulated the overall aroma profile of FBT successfully. Furthermore, omission experiments confirmed that 15, 20, and 15 key odor-active compounds in CJX, QJX, and FJX FBT, respectively. This study will provide a theoretical basis for comprehensively understanding the formation of characteristic aromas in FBT.

Identifying markers volatiles in Brazilian virgin oil by multiple headspace solid-phase microextraction, and chemometrics tools.

A protocol was optimized to determine the volatile profile from monovarietal virgin olive oil (VOO) by multiple headspace solid-phase microextraction (MHS-SPME) followed by gas chromatography-mass spectrometry (GC-MS) analysis. For this, a Plackett-Burman (PB) and central composite rotational designs (CCRD) were used to define the best condition of extraction. Moreover, fatty acids profile and principal component analysis (PCA) was used to identify markers among the cultivars. The amount of 0.1 g of sample was enough to express the volatile composition of the olive oils by MHS-SPME. Volatile compounds [nonanal, (Z)-3-Hexen-1-ol, (Z)-3-Hexenyl Acetate, Hexyl Acetate, 3-Methylbutyl Acetate, (E)-2-Hexen-1-ol, (E)-2-Hexenyl Acetate] and fatty acids [C17:1, C18, C18:1, C18:2] were those reported such as the markers in the varieties of olive oils. The PCA analysis allowed the classification of the most representative volatiles and fatty acids for each cultivar. Through two principal components was possible to obtain 81.9% of explanation of the variance of the compounds. The compounds were quantified using a validated method. The MHS-SPME combined with multivariate analysis showed a promising tool to identify markers and for the discrimination of olive oil varieties.

Influence of peeling on volatile and non-volatile compounds responsible for aroma, sensory, and nutrition in ginger (Zingiber officinale).

Industrial use of ginger after peeling results in large amounts of agro-waste. To provide a basic reference for the sustainable processing of ginger products as a spice, we investigated the differences between unpeeled ginger, peeled ginger, and corresponding ginger peel, in terms of aroma, sensory profiles, and nutrition relevant physicochemical properties. The results showed that the total concentrations of identified odor-active compounds in unpeeled ginger, peeled ginger, and ginger peel were 876.56, 672.73, and 105.39 mg/kg, respectively. Unpeeled ginger exhibited more intense citrus-like and fresh impressions compared to peeled ginger, revealed by descriptive sensory analyses. This is relevant to the high odor activity values of odorants such as ß-myrcene (pungent, citrus-like), geranial (citrus-like), citronellal (citrus-like, sourish), and linalool (floral, fresh). In parallel, unpeeled ginger contained higher total polyphenol (84.49 mg/100 g) and total sugar content (33.4 g/kg) in comparison with peeled ginger (76.53 mg/100 g and 28.6 g/kg).

Pipecolic acid synthesis is required for systemic acquired resistance and plant-to-plant-induced immunity in barley.

Defense responses in plants are based on complex biochemical processes. Systemic acquired resistance (SAR) helps to fight infections by (hemi-)biotrophic pathogens. One important signaling molecule in SAR is pipecolic acid (Pip), accumulation of which is dependent on the aminotransferase ALD1 in Arabidopsis. While exogenous Pip primes defense responses in the monocotyledonous cereal crop barley (Hordeum vulgare), it is currently unclear if endogenous Pip plays a role in disease resistance in monocots. Here, we generated barley ald1 mutants using CRISPR/Cas9, and assessed their capacity to mount SAR. Endogenous Pip levels were reduced after infection of the ald1 mutant, and this altered systemic defense against the fungus Blumeria graminis f. sp. hordei. Furthermore, Hvald1 plants did not emit nonanal, one of the key volatile compounds that are normally emitted by barley plants after the activation of SAR. This resulted in the inability of neighboring plants to perceive and/or respond to airborne cues and prepare for an upcoming infection, although HvALD1 was not required in the receiver plants to mediate the response. Our results highlight the crucial role of endogenous HvALD1 and Pip for SAR, and associate Pip, in particular together with nonanal, with plant-to-plant defense propagation in the monocot crop barley.