Search Results (42)

This study aimed to analyze the volatile organic compounds (VOCs) for different rice aroma types using sensory evaluation, headspace solid-phase microextraction gas chromatography mass spectrometry (HS-SPME-GC-MS), and gas chromatography-ion mobility spectrometry (GC-IMS) techniques, and to explore the material basis for the flavor differences. Based on the sensory evaluation results, rice aroma was categorized into three types, distinguished by their unique aroma compounds. Type A was characterized by a prominent sweet, popcorn aroma, type B by a more prominent cereal and starchy flavor, and type C by a more complex aroma. Untargeted metabolomics analysis using HS-SPME-GC-MS identified and characterized 74 volatile compounds. A comparison of A versus B versus C revealed 8 key aroma compounds, primarily alkanes, aldehydes, ketones, alcohols, and heterocyclic compounds. (E)-2-Octenal, 6-Undecanone, 2-Acetyl-1h-pyrrole, and P-menthan-1-ol in type A gave it a better sweet aroma, Dodecane, 2,6,10-trimethyl-, 1-Octen-3-one, and 2-Methyldecane in type B gave it a better starchy and cereal flavor. 2-Acetyl-1h-pyrrole, Heptacosane, and 1-Propanol in type C contributed to a complex aroma. GC-IMS analysis showed that the fingerprints of rice with different aroma types were significantly different. The VOCs of aroma type A contained (+)-limonene, 2-methylpyrazine, 2-pentanone, ethyl butanoate, n-pentanal, styrene, 1-butanol, 3-methyl-, acetate, 1-hexanal, 1-pentanol, and 2-heptanone, which gave it a better sweet aroma. The VOCs of aroma type C contained 1-octen-3-ol, 2,6-dimethyl pyrazine, 2-acetylpyridine, and ethyl hexanoate, which gave it a better complex aroma. Full article

Tilapia is a cornerstone species in global aquaculture, yet the impact of saline-alkaline adaptive breeding on its flavor-related volatile organic compounds (VOCs) remains unclear. Herein, we compared VOCs in freshwater-cultured tilapia (FW) and 7th-generation tilapia subjected to long-term selective breeding for saline-alkaline tolerance (SAW_G7) using an electronic nose (E-nose), gas chromatography-ion mobility spectrometry (GC-IMS), and headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). The aim was to identify flavor differentiation and assess the effect of saline-alkaline acclimation. E-nose analysis revealed distinct odor profiles, with SAW_G7 showing higher sensor responses for aldehydes, ketones, and alcohols. GC-IMS detected 32 VOCs, highlighting significant increases in alcohols, aldehydes, and heterocyclics in SAW_G7. GC-MS identified 43 VOCs, with orthogonal partial least-squares discriminant analysis (OPLS-DA) confirming 18 discriminant compounds, including elevated ketones (2-undecanone), aldehydes ((E)-2-octenal), alcohols (2,7-Octadien-1-ol), and furans (2-ethyl-Furan) in SAW_G7, linked to lipid oxidation under saline-alkaline stress. These findings demonstrate that long-term saline-alkaline breeding achieves a potentially more diverse VOC profile in tilapia by altering its volatile profiles. The study provides insights for optimizing aquaculture practices to improve product quality in marginal environments. Full article

This study investigated the individual and synergistic impacts of arbuscular mycorrhizal fungi (AMF) inoculation and foliar-applied silicon nanoparticles (SiNPs) on the yield parameters, volatile profile, and phenolic composition of two Rosa damascena genotypes (D231 and C193). Experiments were conducted using a split–split–plot design, involving AMF inoculation (main plot), three SiNPs concentrations (subplot), and two rose genotypes (sub-subplot). The results demonstrated that AMF, SiNPs, and genotype all had significant and interactive effects on flower yield parameters. Foliar application of SiNPs, particularly when combined with AMF inoculation, consistently enhanced flowering parameters, including flower size, number, and weight across both genotypes. High-performance liquid chromatography (HPLC) further confirmed that phenolic acids (vanillic acid and rutin) increased following foliar application of SiNPs and AMF root colonization, particularly in genotype C193. SPME-Arrow analysis revealed that alcohols, ketones, and terpenes were the predominant volatile constituents. Phenethyl alcohol was the most abundant compound, accounting for approximately 84.69% of the total aroma content and contributing significantly to the ‘rose’ aroma. Other major volatiles included 2-undecanone (4.42%), benzyl alcohol (2.97%), and citronellol (1.95%); however, their levels varied depending on treatment and genotype. These findings highlight that the combined application of AMF and SiNPs offers a sustainable approach to enhancing both the quantitative yield and qualitative phytochemical composition (essential oil components and phenolic compounds) of R. damascena, providing a scientific foundation for optimizing its production in organic farming systems. Full article

Lactic acid bacteria (LAB) are widely utilized in the production of various fermented foods. Lacticaseibacillus casei (Ls. casei) fermentation has been demonstrated to enhance antioxidant activity, flavor, and nutritional value. This study aimed to evaluate the physicochemical properties, proximate chemical compositions, antioxidant activities, and volatile profiles of pineapple juice fermented by Ls. casei LK-1. Strain growth, physicochemical parameters, phenolics and flavonoids, carbohydrates, organic acids (by HPLC), free amino acids (FAAs), antioxidant activities (DPPH and FRAP methods), and volatile profiles (by GC-MS) of fermented pineapple juice were characterized. After 30 h of fermentation, the cell count reached 9.07 log CFU/mL. The fermentation process led to a significant decrease in pH, total soluble solids (TSS), and the a* value (p < 0.05), with an increase in the L* and b* values (p < 0.05). Lactic acid and total umami amino acids were elevated, whereas sucrose and total sweet amino acid levels remained unchanged. The fermented juice exhibited enhanced DPPH scavenging activity and FRAP values. In terms of volatile profiles, esters and terpenes were the dominant volatiles in the fermented pineapple juice. The fermentation resulted in the production of 2-heptanone, 2-undecanone, and a significant reduction in 2-furaldehyde (p < 0.05). These findings demonstrate the feasibility of using Ls. casei LK-1 for fermentation to develop novel fermented pineapple juice with improved antioxidant properties and a modified volatile profile. Full article

Two-dimensional gas chromatography-time-of-flight mass spectrometry (GC × GC-TOF MS) was employed to analyze the volatile flavor compounds (VOCs) of Tricholoma matsutake samples from six different geographical regions: CX (Chuxiong), DL (Dali), DQ (Diqing), JL (Yanji), SC (Xiaojin) and XZ (Linzhi). The result indicate that a total of 2730 kinds of VOCs were identified from the fruiting bodies of six T. matsutake samples. The primary types of volatile organic compounds identified were 349 alcohols, 92 aldehydes, 146 carboxylic_acids, 311 esters, 742 organoheterocyclic compounds, 630 hydrocarbons, 381 ketones, 51 organic acids, and 28 derivatives and organosulfur compounds. Furthermore, PCA and PLS-DA analysis from the GC×GC-ToF-MS showed that samples from different regions could be distinguished by their VOCs. Network analysis revealed that 33 aroma compounds were identified as markers for distinguishing the samples from the six regions. The sensory attributes sweet, fruity, green, waxy, and floral were found to be more significant to the flavor profile of T. matsutake. 1-Nonanol, 2-Nonanone, Nonanoic acid, ethyl ester, 1-Undecanol, 2-Undecanone, Octanoic acid, ethyl ester, 2H-Pyran, and tetrahy-dro-4-methyl-2-(2-methyl-1-propenyl)- primarily contribute to the differences in the aroma characteristics among six T. matsutake samples. The results also provide a theoretical and practical foundation for the flavor compounds of these precious edible fungi in different regions. Full article

Apart from the importance of bittering acids in the brewing sector, hops also produce terpene-rich essential oils, recognised for their therapeutic benefits. Agri-processing practices of this crop in South Africa produce tonnes of discarded (waste) plant material that could still contain sufficient bioactive compounds to justify upcycling. This research aimed to determine the chemical composition of steam distilled essential oils from fresh hop plant material destined for disposal. Essential oils from eight hop varieties unique to South Africa were produced on industrial scale using steam distillation. Chemical profiling was performed using GC-FID and MS. A total of 208 compounds were identified and oil consisted largely of terpenes (89.04 ± 1.89%) as well as aliphatic esters and -ketones (6.1 ± 1.15%). Myrcene (27.8–48.15%) was the most abundant monoterpene and α-humulene (19.52–24.98%), β-caryophyllene (8.47–13.73%) and β-farnesene (2.08–7.57%) constituted the majority of the sesquiterpenes fraction. Experimental variety XJA2/436 had the highest myrcene fraction (48.15%) and its chemical composition was markedly different from the other varieties. The major compounds in African Queen hop oil were methyl (4Z) decanoate (0.74%), 2-tridecanone (0.77%) and β-farnesene (7.57%). Southern Dawn hop oil contained the highest fractions of 2-undecanone (1.21%) and α-humulene (24.89%) and Southern Passion hop oil contained the highest β-caryophyllene fraction (13.73%). These findings established that fresh hop vegetative biomass shows promise to be transformed into a valuable resource. Full article

Liquid and vapor phase transfer hydrogenation with 2-alkanols as hydrogen donors in the presence of MgO as a catalyst was studied. A series of dicarbonyl compounds as well as the equimolar mixtures of various monocarbonyl compounds were used as hydrogen acceptors in order to determine the chemoselectivity (ChS) in the reduction of their carbonyl groups. Thus, 1,4-diacetylbenzene was reduced to 1-(4-acetylphenyl)-1-ethanol with 89% ChS and 1,3-diacetyl-4,6-dimethylbenzene with 100% ChS. Mesitylene diacyl derivatives were unreactive in the studied reaction. CTH of an equimolar mixture of benzaldehyde and acetophenone gave benzyl alcohol and 1-PhEtOH with yields of 91 and 3%, respectively (97% ChS). An equimolar mixture of acetophenone and 6-undecanone underwent CTH with yields of the corresponding alcohols of 89 and 2%, respectively, with 98% ChS towards 1-PhEtOH. Significant differences in reactivity in CTH were reported for an equimolar mixture of regioisomeric 1- and 2-acetylnaphthalenes. The yields of the corresponding alcohols were 20 and 68% with a ChS of 77% towards 2-NphCH(OH)Me. In the case of CTH of 3-oxo-2,2-dimethylbutanal and 2,4-bis(spirocyclohexyl)-1,3-cyclobutanedione with 2-propanol, only the solvolysis of the substrates was observed. The products were methyl isopropyl ketone and isopropyl formate for the former diketone and 1-(cyclohexylcarbonyl)-1-(carboisopropoxy)cyclohexane for the latter. Full article

Pythium spp. are soil-borne pathogens that cause damping-off and root rot diseases in many plant species such as cucumber. In the current study, the effect of dried roots–stems and leaves of Ageratina adenophora (Sprengel) R. King and H. Robinson (=Eupatorium adenophorum Sprengel) alone and in combination with pyrogenic biomass biochar to control Pythium aphanidermatum (Edson) Fitz was assessed. In four treatments of leaves, roots–stems, leaves + biochar, and roots–stems + biochar, it was observed that the treatment with leaves at an E_max (maximal effective concentration on control fungi) of 79 g/kg of soil had the most antifungal effect on P. aphanidermatum. Also, the C_max (the highest level of control) increased with time and reached 82.4% and 71% on days 30 and 60, respectively. The highest cucumber fresh fruit weight and the highest height of the stems in the greenhouse were observed in leaf treatment of A. adenophora. Biochar did not have any remarkable controlling effect on P. aphanidermatum, and its population increased. The main compounds extracted from the dried leaves and roots–stems of A. adenophora, including α-pinene, nonanone, hexahydronaphthalene, 3-undecanone, muurolene, and heneicosane, had antifungal properties. We concluded that the leaves of A. adenophora have the potential to be used as a bio-fumigant for P. aphanidermatum management. Full article

Although only a few species of Tuber account for the major truffle sales volume, many species that are not considered delicacies are finding their way to the market, especially in regions where the traditionally appreciated ones do not occur. This is the case for whitish truffles. Specimens of whitish truffles were collected in pecan (Carya illinoinensis) orchards in Uruguay in October 2021. Morphological and molecular methods were used to characterize and assess their identity as Tuber maculatum Vittad. An SPME extraction of volatile compounds and GC–MS analyses were performed to characterize the aromatic profile of these specimens and evaluate their potential applications. Among the 60 VOCs detected, 3-octenone (mushroom odor), 3-octanol (moss, nut, mushroom odor), and 2H-pyran-2-one (no odor), followed by octen-1-ol-acetate (no odor) and 2-undecanone (orange, fresh, green odor) were the major compounds in T. maculatum fruiting bodies. The attributes of exotic edible mushrooms of commercial value in the region are highlighted. In particular, this work emphasizes the characteristics of truffles as a byproduct of pecan cultivation. Full article

The U.S. Department of Agriculture (USDA) has established research programs to fight the phytopathogen Colletotrichum fragariae and the invasive red imported fire ant, Solenopsis invicta. C. fragariae is known to cause anthracnose disease in fruits and vegetables, while S. invicta is known for its aggressive behavior and painful stings and for being the cause of significant damage to crops, as well as harm to humans and animals. Many plants have been studied for potential activity against C. fragariae and S. invicta. Among the studied plants, Houttuynia cordata Thunb has been shown to contain 2-undecanone, which h is known for its antifungal activity against Colletotrichum gloesporioides. Based on the mean amount of sand removed, 2-undecanone showed significant repellency at 62.5 µg/g, similar to DEET (N,N-diethyl-meta-toluamide), against S. invicta. The 2-Undecanone with an LC₅₀ of 44.59 µg/g showed toxicity against S. invicta workers. However, neither H. cordata extract nor 2-undecanone had shown activity against C. fragariae despite their known activity against C. gloesporioides, which in turn motivates us in repositioning 2-undecanone as a selected candidate for a Claisen–Schmidt condensation that enables access to several analogs (2a–f). Among the prepared analogs, (E)-1-(3-methylbenzo[b]thiophen-2-yl)dodec-1-en-3-one (2b) and (E)-1-(5-bromothiophen-2-yl)dodec-1-en-3-one (2f) showed promising activity against C. fragariae, revealing a distinctive structural activity relationship (SAR). The generated analogs revealed a clear regioselectivity pattern through forming the C=C alkene bond at position C-1. These data open the window for further lead optimization and product development in the context of managing C. fragariae and S. invicta. Full article

Zanthoxylum armatum DC. is a plant that has been homologated for medicine and food by the Chinese for three thousand years. In this study, the essential oils of fresh leaves and fruits were extracted by hydrodistillation, the aromas of fresh leaves and fruits were extracted by headspace solid-phase microextraction and their chemical compositions were analyzed by gas chromatography mass spectrometry. The main components of the leaf essential oils were linalool (62.01%), 2-undecanone (9.83%) and 2-tridecanone (5.47%); the fruit essential oils were linalool (72.17%), limonene (8.05%) and sabinene (6.77%); the leaf aromas were limonene (39.15%), β-myrcene (15.8%), sabinene (8.17%) and linalool (5.25%); the fruit aromas were limonene (28.43%), sabinene (13.56%), linalool (11.47%) and β-myrcene (8.64%). By comparison, it was found that the composition of leaf essential oils and fruit essential oils were dominated by oxygenated monoterpenes, while the composition of their aromas were both dominated by monoterpenes; the relative content of non-terpene components in leaf essential oil and leaf aroma is second only to oxygenated monoterpenes, while their content in fruits is low; the chemical composition of leaf aromas and fruit aromas were richer than those of essential oils. In this study, we reported for the first time that the antitumor, tyrosinase inhibition, HMGR inhibition and nitric oxide production inhibition activity of leaf essential oils were stronger than those of fruit essential oils in in vitro tests. The results of the study can provide a reference for the recycling and green low-carbon transformation of the leaves, and also help to deepen the understanding of the value of the volatile chemical constituents of this plant in “forest medicine” or “aromatherapy”, and provide new ideas for the transformation of the value of the plant in the secondary and tertiary industry chain. Full article

In order to study the effect of both greenhouse and forest cultivating environments on Stropharia rugosoannulata, its volatile aroma compounds were measured by a headspace solid phase micro extractions—gas chromatograph—mass spectrometer (SPME–GC–MS). The optimal adsorption temperature was 75 °C and the optimal adsorption time was 40 min. A total of 36 volatile aroma compounds were identified by GC–MS, including 8 aldehydes, 2 ketones, 4 alcohols, 15 alkenes, and 4 alkanes. Hexanal, 3-Octanone, 2-Undecanone, (E)-Nerolidol, and (Z)-β-Farnesene made great aromatic contributions. Among them, Hexanal, 3-Octanone, 2-Undecanone were the key aroma compounds for which odor activity values (OAVs) were more than 1. (E)-Nerolidol showed odor modification in the forest samples and showed a key aroma effect in greenhouse samples. (Z)-β-Farnesene showed odor modification in greenhouse samples. 3-Octanone was the largest contributing compound for which the OAV was more than 60. The total content of volatile aroma compounds first increased and then decreased with growth time; it reached the highest level at 48 h: 2203.7 ± 115.2 μg/kg for the forest environment and 4516.6 ± 228.5 μg/kg for the greenhouse environment. The aroma was the most abundant at this time. All samples opened their umbrella at 84 h and become inedible. Principal component analysis (PCA), hierarchical cluster analysis (HCA), and orthogonal partial least squares discriminant analysis (OPLS–DA) were combined to analyze the aroma difference of S. rugosoannulata under two cultivation modes. PCA and HCA could effectively distinguish the aroma difference in different growth stages. Under different culturing methods, the aroma substances and their changes were different. The samples were divided into two groups for forest cultivation, while the samples were divided into three groups for greenhouse cultivation. At the end of growth, the aroma of S. rugosoannulata with the two cultivation modes was very similar. OPLS–DA clearly distinguished the differences between the two cultivation methods; 17 key aroma difference factors with variable importance projection (VIP) > 1 were obtained from SPLS–DA analysis. Full article

The interaction perception between aroma and oral chewing during food consumption has always been a hot topic in exploring consumers’ preferences and purchase desires. A chewing simulation system was set to find out the effect of key saliva components and chewing time on odorants released with grilled eel meat. Odor release did not always enhance with the degree of chewing, or the amount of saliva released. The breaking up of the tissue structure of the fish meat by the teeth encourages the release of odorants and the participation of saliva partially blocks this process. The release of pyrazine, alcohol, and acid compounds in grilled eel meat peaked within 20–60 s after chewing. Sufficient exposure of saliva to grilled eel meat will inhibit aromatic, ketone, ester, hydrocarbon, and sulfur compounds release. 3-methyl-2-butanol contributed to the subtle aroma differences that arise before and after eating grilled eel meat. Naphthalene, 2-acetylthiazole, 2-decenal, 2-undecanone, 5-ethyldihydro-2(3H)-furanone were the main odorants released in large quantities in the early stages of eating grilled eel and affected the top note. Consequently, the results provided the odorants information in aroma perception during grilled eel consumption and benefited the objective evaluation of grilled eel product optimization. Full article

Volatile organic compounds (VOCs) make up milk flavor and are essential attributes for consumers to evaluate milk quality. In order to investigate the influence of heat treatment on the VOCs of milk, electronic nose (E-nose), electronic tongue (E-tongue) and headspace solid-phase microextraction (HS-SPME)–gas chromatography–mass spectrometry (GC-MS) technology were used to evaluate the changes in VOCs in milk during 65 °C heat treatment and 135 °C heat treatment. The E-nose revealed differences in the overall flavor of milk, and the overall flavor performance of milk after heat treatment at 65 °C for 30 min is similar to that of raw milk, which can maximize the preservation of the original taste of milk. However, both were significantly different to the 135 °C-treated milk. The E-tongue results showed that the different processing techniques significantly affected taste presentation. In terms of taste performance, the sweetness of raw milk was more prominent, the saltiness of milk treated at 65 °C was more prominent, and the bitterness of milk treated at 135 °C was more prominent. The results of HS-SPME-GC-MS showed that a total of 43 VOCs were identified in the three types of milk—5 aldehydes, 8 alcohols, 4 ketones, 3 esters, 13 acids, 8 hydrocarbons, 1 nitrogenous compound, and 1 phenol. The amount of acid compounds was dramatically reduced as the heat treatment temperature rose, while ketones, esters, and hydrocarbons were encouraged to accumulate instead. Furfural, 2-heptanone, 2-undecanone, 2-furanmethanol, pentanoic acid ethyl ester, 5-octanolide, and 4,7-dimethyl-undecane can be used as the characteristic VOCs of milk treated at 135 °C. Our study provides new evidence for differences in VOCs produced during milk processing and insights into quality control during milk production. Full article

Ruta chalepensis L., commonly known as Shazab in Saudi Arabia, is one of the famous culinary plants belonging to the Rutaceae family. It is commonly used in ethnomedicine in treating numerous diseases. This study was performed to characterize the essential oil isolated from Saudi species using a relatively new advanced headspace solid-phase microextraction technique. Following that, the antioxidant activity of the extracted oil was assessed using in vitro techniques such as the DPPH and nitric oxide scavenging tests, as well as the reducing power FRAP study and the molecular docking tool. The essential oil yield of the dried plant was 0.83% (v/w). Gas chromatography joined with a mass spectrometer was used to determine the chemical composition of the pale-yellow essential oil. Sixty-eight constituents were detected, representing 97.70% of the total oil content. The major constituents were aliphatic ketones dominated by 2-undecanone (37.30%) and 2-nonanone (20.00%), with minor constituents of mono and sesquiterpenoids chemical classes. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase is one of the major causes of many contemporary diseases due to its ability to create a reactive oxygen species (ROS). Thus, molecular docking was used to confirm that some oil phytoconstituents have good docking scores compared to the standard antioxidant drug (Vitamin C), indicating great binding compatibility between the (NADPH) oxidase receptor site and the ligand. In conclusion, our findings suggest that the oil could be used safely and as a cost-effective remedy in treating various modern diseases caused by free radical formation. Full article