Identification of VOCs in essential oils extracted using ultrasound- and microwave-assisted methods from sweet cherry flower

Recent advances in the implementation of ultrasound technology for the extraction of essential oils from terrestrial plant materials: A comprehensive review

Ultrasound-assisted extraction (UAE) is an innovative process for recovering valuable substances and compounds from plants and various biomaterials. This technology holds promise for resource recovery while maintaining the quality of the extracted products. The review comprehensively discusses UAE's mechanism, applications, advantages, and limitations, focusing on extracting essential oils (EOs) from diverse terrestrial plant materials. These oils exhibit preservation, flavor enhancement, antimicrobial action, antioxidant effects, and anti-inflammatory benefits due to the diverse range of specific compounds in their composition. Conventional extraction techniques have been traditionally employed, and their limitations have prompted the introduction of novel extraction methods. Therefore, the review emphasizes that the use of UAE, alone or in combination with other cutting-edge technologies, can enhance the extraction of EOs. By promoting resource recovery, reduced energy consumption, and minimal solvent use, UAE paves the way for a more sustainable approach to harnessing the valuable properties of EOs. With its diverse applications in food, pharmaceuticals, and other industries, further research into UAE and its synergies with other cutting-edge technologies is required to unlock its full potential in sustainable resource recovery and product quality preservation.

Characterization of Key Odorants in Lushan Yunwu Tea in Response to Intercropping with Flowering Cherry

Lushan Yunwu tea (LSYWT) is a famous green tea in China. However, the effects of intercropping tea with flowering cherry on the overall aroma of tea have not been well understood. In this study, headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) was used for analysis. A total of 54 volatile compounds from eight chemical classes were identified in tea samples from both the intercropping and pure-tea-plantation groups. Principal component analysis (PCA), orthogonal partial least-squares discriminant analysis (OPLS-DA), and odor activity value (OAV) methods combined with sensory evaluation identified cis-jasmone, nonanal, and linalool as the key aroma compounds in the intercropping group. Benzaldehyde, α-farnesene, and methyl benzene were identified as the main volatile compounds in the flowering cherry using headspace solid-phase microextraction/gas chromatography-mass spectrometry (HS-SPME/GC-MS). These findings will enrich the research on tea aroma chemistry and offer new insights into the product development and quality improvement of LSYWT.

Rapid Identification of Aphid Species by Headspace GC-MS and Discriminant Analysis

Aphids are a ubiquitous group of pests in agriculture that cause serious losses. For sustainable aphid identification, it is necessary to develop a precise and fast aphid identification tool. A new simple chemotaxonomy approach to rapidly identify aphids was implemented. The method was calibrated in comparison to the established phylogenetic analysis. For chemotaxonomic analysis, aphids were crushed, their headspace compounds were collected through closed-loop stripping (CLS) and analysed using gas chromatography-mass spectrometry (GC-MS). GC-MS data were then subjected to a discriminant analysis using CAP12.exe software, which identified key biomarkers that distinguish aphid species. A dichotomous key taking into account the presence and absence of a set of species-specific biomarkers was derived from the discriminant analysis which enabled rapid and reliable identification of aphid species. As the method overcomes the limits of morphological identification, it works with aphids at all life stages and in both genders. Thus, our method enables entomologists to assign aphids to growth stages and identify the life history of the investigated aphids, i.e., the food plant(s) they fed on. Our experiments clearly showed that the method could be used as a software to automatically identify aphids.

Identification of volatile compounds and metabolic pathway during ultrasound-assisted kombucha fermentation by HS-SPME-GC/MS combined with metabolomic analysis

The current work combines headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC/MS) with multivariate analysis fusion metabonomics for examining metabolite profile changes. The correlation with metabolic pathways during the fermentation of kombucha tea were comprehensively explored. For optimizing the fermentation process, ultrasound-assisted factors were explored. A total of 132 metabolites released by fermented kombucha were detected by HS-SPME-GC/MS. We employed the principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) to present the relationship between aroma components and fermentation time, of which the first two principal components respectively accounted for 60.3% and 6.5% of the total variance. Multivariate statistical analysis showed that during the fermentation of kombucha tea, there were significant differences in the phenotypes of metabolites in the samples, and 25 characteristic metabolites were selected as biomarkers. Leaf alcohol was first proposed as the characteristic volatile in the fermentation process of kombucha. Furthermore, we addressed the generation pathways of characteristic volatiles, their formation mechanisms, and the transformational correlation among them. Our findings provide a roadmap for future kombucha fermentation processing to enhance kombucha flavor and aroma.

How the volatile organic compounds emitted by corpse plant change through flowering

The corpse plant (Amorphophallus titanum) is so named because it produces a pungent, foul odor when flowering. Little is known about how the emitted volatiles change throughout the two-day flowering period. In this study, the comprehensive monitoring of the presence and change in volatile molecules during the female and the male flowering phases of A. titanum was conducted, and the plant temperature was monitored. A total of 422 volatile features were detected over the entire sampling period, of which 118 features were statistically significantly different between the pre-flowering and both flowering phases, and an additional 304 features were found present throughout the flowering period. A total of 45 molecules could be assigned putative names. The volatile profile of A. titanum changes over the two-day flowering period, with the S-containing molecules and aldehydes dominant in the female flowering phase, and the alcohols and hydrocarbons dominant in the male flowering phase. The two-dimensional gas chromatography time-of-flight mass spectrometry (GC × GC-TOFMS) enabled us to identify 32 new molecules produced by A. titanum. Each of these molecules alone, and in combination, likely contribute to the different odors emitted during the flowering phase of A. titanum.

A Background Search on the Potential Role of Scutellaria and Its Essential Oils

Scutellaria (Lamiaceae), which contains over 350 species, usually known as skullcaps, is found throughout Europe, the United States, and East Asia. In traditional Chinese medicine, several species are used to wipe out heat-evil and remove surface ills (TCM). The current study examines the ethnopharmacology, biological activity, and chemical substances associated with Scutellaria species. More than 295 chemicals, including flavonoids and diterpenes, have been identified. Scutellaria and its active principles have been shown in studies to have a wide range of pharmacological activities, including antioxidant, antimicrobial, antifeedant, phytotoxic, acaricidal toxicity, antibacterial, anti-inflammatory, and antianalgesic activities. Currently, effective monomeric compounds or active components from Scutellaria have been evaluated for pharmacological action in vivo and in vitro. More data facilitates applications and exploitation of novel medication development.

Mineral Content and Volatile Profiling of Prunus avium L. (Sweet Cherry) By-Products from Fundão Region (Portugal)

Large amounts of Prunus avium L. by-products result from sweet cherry production and processing. This work aimed to evaluate the mineral content and volatile profiling of the cherry stems, leaves, and flowers of the Saco cultivar collected from the Fundão region (Portugal). A total of 18 minerals were determined by ICP-MS, namely 8 essential and 10 non-essential elements. Phosphorus (P) was the most abundant mineral, while lithium (Li) was detected in trace amounts. Three different preparations were used in this work to determine volatiles: hydroethanolic extracts, crude extracts, and aqueous infusions. A total of 117 volatile compounds were identified using HS-SPME/GC-MS, distributed among different chemical classes: 31 aldehydes, 14 alcohols, 16 ketones, 30 esters, 4 acids, 4 monoterpenes, 3 norisoprenoids, 4 hydrocarbons, 7 heterocyclics, 1 lactone, 1 phenol, and 2 phenylpropenes. Benzaldehyde, 4-methyl-benzaldehyde, hexanal, lilac aldehyde, and 6-methyl-5-hepten-2-one were the major volatile compounds. Differences in the types of volatiles and their respective amounts in the different extracts were found. This is the first study that describes the mineral and volatile composition of Portuguese sweet cherry by-products, demonstrating that they could have great potential as nutraceutical ingredients and natural flavoring agents to be used in the pharmaceutical, cosmetic, and food industries.