Antioxidant activity screening and chemical constituents of the essential oil from rosemary by ultra-fast GC electronic nose coupled with chemical methodology

A study of volatiles of young citrus fruits from four areas based on GC-MS and flash GC e-nose combined with multivariate algorithms

The present study has successfully established a scientific and precise approach for distinguishing the geographical origins of young citrus fruits (Qingpi) from four primary production regions in China, using gas chromatography-mass spectrometry (GC-MS) and flash gas chromatography electronic nose (flash GC e-nose) to analyze the volatile composition and odor characteristics. Through the application of chemometric analysis, a clear differentiation among Qingpi samples was established using GC-MS. Additionally, the application of flash GC e-nose facilitated the extraction of flavor information, which enabled the discrimination of geographical origins. Several flavor components were identified as significant factors for origin certification. Furthermore, two pattern recognition algorithms were employed to achieve high accuracy in regional identification. The results of this investigation demonstrate that the amalgamation of multivariate chemometrics and algorithms can proficiently discern the sources of those young citrus fruits. The findings of this research can provide a reference for the assessment of quality control in food and other agricultural commodities in the times ahead.

E-eye, flash GC E-nose and HS-GC-MS combined with chemometrics to identify the adulterants and geographical origins of Ziziphi Spinosae Semen

Ziziphi Spinosae Semen (ZSS), a valuable seed food, has faced increasing authenticity issues. In this study, the adulterants and geographical origins of ZSS were successfully identified by electronic eye, flash gas chromatography electronic nose (Flash GC e-nose) and headspace gas chromatography-mass spectrometry (HS-GC-MS). As a result, there were color differences between ZSS and adulterants, mainly represented by the a* value of ZSS was less than adulterants. In ZSS, 29 and 32 compounds were detected by Flash GC e-nose and HS-GC-MS. Spicy, sweety, fruity and herbal were the main flavor of ZSS. Five compounds were determined to be responsible for flavor differences between different geographical origins. In the HS-GC-MS analysis, the relative content of Hexanoic acid was the highest in ZSS from Hebei and Shandong, while 2,4-Decadien-1-ol was the highest in Shaanxi. Overall, this study provided a meaningful strategy for addressing authenticity problems of ZSS and other seed foods.

Chemical Composition Analysis and Discrimination of Essential Oils of Artemisia Argyi Folium from Different Germplasm Resources Based on Electronic Nose and GC/MS Combined with Chemometrics

In this study, the electronic nose and GC/MS were used to analyze the chemical components of essential oils from different germplasm resources of Artemisia argyi Folium (A. argyi), in order to quickly identify essential oils of A. argyi from different germplasm resources and clarify the differences among different A. argyi samples. The essential oils of A. argyi were extracted by steam distillation. This article describes for the first time that electronic nose combined with chemometrics can distinguish the essential oils of A. argyi from different germplasm, which proves the reliability and potential of this technology. GC/MS was used to identify 134 volatile components from the essential oil of A. argyi. The main bioactive components were cineole, thujarone, artemisia ketone, β-caryophyllene, (-)-4-terpinol, 3,3,6-trimethyl-1,5-heptadien-4-ol, (-)-α-thujone, camphor, borneol. In addition, the results of principal component analysis (PCA) and hierarchical cluster analysis (HCA) showed that there were significant differences in the essential oils of A. argyi from different germplasm resources, terpenes, alcohols and ketones played an important role in identifying the essential oils of A. argyi from different germplasm resources. This indicates that electronic nose and GC/MS combined with chemometrics can be used as reliable techniques to identify different germplasm resources of A. argyi, and provide certain reference value for quality evaluation, selection of high-quality varieties and rational development of resources of A. argyi.

Antioxidant and antidiabetic compounds identification in several Indonesian underutilized Zingiberaceae spices using SPME-GC/MS-based volatilomics and in silico methods

•

Volatile compounds linked with antidiabetic and antioxidant activity of 12 Zingiberaceae spices were identified using SPME-GC/MS and multivariate data analysis.

•

Eucalyptol strongly correlated with α-glucosidase inhibitor and DPPH antioxidant activity.

•

o-Cymene and terpinen-4-ol strongly correlated with FRAP and CUPRAC antioxidant activity.

•

In silico study supported the results of the in-vitro experiment.

This study aimed to identify compounds in 12 minor Zingiberaceae spices grown in Indonesia linked with in vitro α-glucosidase inhibitor and antioxidant (DPPH, FRAP, CUPRAC) activities using SPME-GC/MS volatilomics. The results illustrated that Zingiber aromaticum Val., Alpinia malaccensis (Burm.f.) Roscoe, Amomum compactum Sol. ex Maton, and Zingiber purpureum Roscoe had the highest α-glucosidase inhibitor and DPPH, FRAP, CUPRAC antioxidant activities, respectively. Also, the total phenolic content positively influenced DPPH, FRAP, and CUPRAC antioxidant activities. The strongest positive correlation with α-glucosidase inhibitor and DPPH antioxidant activities was found in eucalyptol; whereas o-cymene and terpinen-4-ol had the strongest correlations with FRAP and CUPRAC antioxidants, respectively. Furthermore, the molecular docking analysis revealed that all compounds with a strong correlation with α-glucosidase inhibitor activity (based on their OPLS VIP score) had binding energies (−5.06 – −6.26 kcal/mol) close to Acarbose (−10.11 kcal/mol). Thus, this study provided vital information on the volatile compounds in underutilized spices associated with their health beneficial properties.

Fast GC E-Nose and Chemometrics for the Rapid Assessment of Basil Aroma

The aim of this work is to assess the potentialities of the synergistic combination of an ultra-fast chromatography-based electronic nose as a fingerprinting technique and multivariate data analysis in the context of food quality control and to investigate the influence of some factors, i.e., basil variety, cut, and year of crop, in the final aroma of the samples. A low = level data fusion approach coupled with Principal Component Analysis (PCA) and ANOVA—Simultaneous Component Analysis (ASCA) was used in order to analyze the chromatographic signals acquired with two different columns (MXT-5 and MXT-1701). While the PCA analysis results highlighted the peculiarity of some basil varieties, differing either by a higher concentration of some of the detected chemical compounds or by the presence of different compounds, the ASCA analysis pointed out that variety and year are the most relevant effects, and also confirmed the results of previous investigations.

Multifaceted functionality of L-arginine in modulating the emulsifying properties of pea protein isolate and the oxidation stability of its emulsions

The effects of L-arginine (Arg) at different concentrations (0%, 0.05%, 0.1%, 0.2%, 0.5% and 1.0%) on the antioxidant activity, structure and emulsifying properties of pea protein isolate (PPI) were explored. The intrinsic mechanisms of the reactions at different concentrations were specifically examined. With an increase in Arg concentration, the scavenging activities of ABTS+˙ and ˙OH and the Fe²⁺ chelating activity of PPI increased significantly (P < 0.05). The addition of Arg (0%-0.2%) significantly modified the PPI structure, causing an increase in protein solubility (from 66.2% to 79.0%) and a decrease in protein particle size (from 682 nm to 361 nm) (P < 0.05). In addition, treatment with Arg (0%-0.2%) effectively improved the emulsifying activity of PPI (by 28%), decreased the droplet size and viscosity of the emulsion, and enhanced the physical and oxidation stabilities of the emulsion. The increase in interfacial protein content and the absolute value of ζ-potential, and the microscopy images also showed that 0%-0.2% Arg treatment helped in forming a uniform and stable microemulsion. In contrast, a high concentration (0.5%-1.0%) of Arg diminished its positive effect on the emulsifying properties of PPI. Therefore, treatment with an appropriate concentration of Arg can significantly improve the emulsifying activity of PPI and enhance the stability of the emulsions.

Antibiofilm and antioxidant activity of Rosmarinus officinalis essential oil

The aim of the work was to explore the antioxidant potential and antibiofilm activity of the Rosmarinus officinalis essential oil. The DPPH method was used to determine the antioxidant activity. The agar microdilution method was used to determine the minimum biofilm inhibiting concentration (MBIC). The MALDI-TOF MS Biotyper was used to evaluate the antibiofilm activity on the wood and glass surface. Vapor phase antimicrobial analysis was used to determine the effect on the food model. The antioxidant activity was 28.76 % ± 2.68 %. The MBIC for Stenotrophomonas maltophilia was 25 µL.mL-1 and for Bacillus subtilis 12.5 µL.mL-1. Analysis of the mass spectra of S. maltophilia revealed an inhibitory effect from the 5th, which persisted until the end of the experiment. Analysis of the mass spectra of B. subtilis showed an inhibitory effect from the 7th of the experiment. The experiments showed an effect on both tested surfaces. The food model showed a more pronounced effect of the Rosmarinus officinalis essential oil against B. subtilis. We assume that the effect of the essential oil is to disrupt the polysaccharide structure of the biofilm and consequently reduce the resistance of the biofilm. We have established that MALDI-TOF MS Biotyper is a suitable tool for evaluating changes in biofilm structure and could find more significant application for the study of biofilms in food and clinical practice.

Influence of dietary supplementation of clove and rosemary essential oils or their combination on growth performance, immunity status, and blood antioxidant of growing rabbits

This study aimed to assess the dietary effects of rosemary and clove essential oils separately and in combination on the growth performance; immunological, hematological, and physiological responses; and antioxidant status of growing rabbits. One hundred forty-four of 42-day-old growing V-line rabbits (both sexes with initial live body weights of 765 ± 6 g) were randomly allocated into four treatment groups of 36 rabbits each. Each group was further sub-divided into 12 replicates of 3 rabbits in a completely randomized design. The 1^st group was fed a basal diet free of additives and served as the control group, the 2^nd and 3^rd groups were fed basal diets supplemented with rosemary and clove essential oils, respectively, at doses of 400 mg/kg diet. The 4^th group received a basal diet supplemented with a combination of clove and rosemary essential oils at doses of 200 mg/kg diet each. The results showed that the different supplementations did not influence rabbit performance or immunological traits. Opposite to performance or immunological traits, differences in red blood cells and hemoglobin value among all dietary treatments were improved (P < 0.05). Dietary essential oil supplementation with clove, rosemary oil, or a mixed of both increased (P < 0.05) blood concentrations of catalase, superoxide dismutase, and glutathione peroxidase by 47, 42, and 7%; 56, 35, and 36%; and 40, 39, and 37%, respectively, in supplemented rabbits versus control rabbits. In conclusion, clove and/or rosemary essential oils can potentially be used in rabbit diets to improve antioxidant status without change in rabbit's growth performance or immunological parameters.

Application of gas chromatography-ion mobility spectrometry (GC-IMS) and ultrafast gas chromatography electronic-nose (uf-GC E-nose) to distinguish four Chinese freshwater fishes at both raw and cooked status

The volatile organic compounds (VOCs) in four Chinese freshwater fishes (i.e., Hypophthalmichthys molitrix (H), Aristichthys nobilis (A), Lateolabrax japonicus (L), Parabramis pekinensis (P)) were separated using gas chromatography-ion mobility spectrometry (GC-IMS) and ultrafast gas chromatography electronic-nose (uf-GC E-nose). Principal component analysis (PCA) was applied to distinguish the VOCs identified from the four freshwater fishes in both raw and cooked states. Twenty compounds were identified from the spectral database of GC-IMS, including five aldehydes, eight alcohols, six ketones, and three esters. In addition, using GC E-nose, 32 compounds were isolated by the first column MTX-5, and 24 compounds were isolated by the second column MXT-1701. PCA results showed that the four fishes could be well discriminated against. The odor profiles of raw and cooked fishes were clearly different. This study demonstrated that specific signals provided from GC-IMS could differentiate freshwater fishes. GC-IMS and uf-GC E-nose could be developed further to distinguish aquatic products based on VOCs. PRACTICAL APPLICATIONS: Two new methods, gas chromatography-ion mobility spectrometry (GC-IMS) and ultrafast gas chromatography electronic-nose (uf-GC E-nose), were used to analyze the volatile organic compounds (VOCs) in four Chinese freshwater fishes at raw and cooked status. GC-IMS has the characteristics of fast detection speed and high sensitivity. The accuracy of the qualitative analysis of the compounds is better with GC-IMS (larger data volume, leading to a better in-depth statistical analysis). Uf-GC E-nose could provide a nondestructive, fast, relatively low cost, and trustworthy way for flavor analysis. According to the techniques, the established fingerprints of VOCs provided an additional tool for food analysis.

Salvia officinalis L. from Italy: A Comparative Chemical and Biological Study of Its Essential Oil in the Mediterranean Context

Salvia officinalis L. (sage) is one of the most appreciated plants for its plethora of biologically active compounds. The objective of our research was a comparative study, in the Mediterranean context, of chemical composition, anticholinesterases, and antioxidant properties of essential oils (EOs) from sage collected in three areas (S1–S3) of Southern Italy. EOs were extracted by hydrodistillation and analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory properties were investigated by employing Ellman’s method. Four in vitro assays, namely, 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferric-reducing ability power (FRAP), and β-carotene bleaching tests, were used to study the antioxidant effects. Camphor (16.16–18.92%), 1,8-cineole (8.80–9.86%), β-pinene (3.08–9.14%), camphene (6.27–8.08%), and α-thujone (1.17–9.26%) are identified as the most abundant constituents. However, the content of these constituents varied depending on environmental factors and pedoclimatic conditions. Principal component analysis (PCA) was performed. Based on Relative Antioxidant Capacity Index (RACI), S2 essential oil exhibited the highest radical potential with an IC₅₀ value of 20.64 μg/mL in ABTS test and presented the highest protection of lipid peroxidation with IC₅₀ values of 38.06 and 46.32 μg/mL after 30 and 60 min of incubation, respectively. The most promising inhibitory activity against BChE was found for S3 sample (IC₅₀ of 33.13 μg/mL).

Characterization and Analysis of Okoume and Aiele Essential Oils from Gabon by GC-MS, Electronic Nose, and Their Antibacterial Activity Assessment

Essential oil resins of Aucoumea klaineana (Okoume) and Canarium schweinfurthii (Aiele) species, of the Burseraceae family, were studied to investigate their bioactive constituents and their antibacterial activities. Aiele resin had a higher yield (6.86%) of essential oil than Okoume (3.62%). Twenty-one compounds for Okoume and eighteen for Aiele essential oil were identified using a gas chromatography-mass spectrometry (Gp-C-MS) technique. The main compounds identified in Okoume essential oil were benzenemethanol, α, α,4-trimethyl (28.85%), (+)-3-carene (3,7,7-trimethyl bicyclo[4.1.0]hept-3-ene) (17.93%), D-Limonene ((4R)-1-methyl-4-prop-1-en-2-ylcyclohexene) (19.36%). With regard to the Aiele essential oil, we identified (1R,4S)-1-methyl-4-propan-2-ylcyclohex-2-en-1-ol (26.64%), and 1-methyl-4-propan-2-ylcyclohex-2-en-1-ol (26.83%). Two strains of bacteria, Escherichia coli and Staphylococcus aureus, were used in antibacterial tests. S. aureus was found to be more sensitive to Okoume and Aiele essential oils, with a high inhibition zone ranging from 20 to 16 mm. In comparison, the inhibition zone ranged from 6 to 12 mm for E. coli. An electronic nose (e-nose) combined with pattern analysis methods such as principal component analysis (PCA), discriminant function analysis (DFA), and hierarchical cluster analysis (HCA) were used to discriminate the essential oil samples. In summary, the e-nose and GC-MS allowed the identification of bioactive compounds in the essential oil samples, which have a strong antimicrobial activity, with satisfactory results.

Tangerines Cultivated on Madeira Island-A High Throughput Natural Source of Bioactive Compounds

Tangerines (Citrus reticulata) are popular fruits worldwide, being rich in many bioactive metabolites. The setubalense variety cultivated on Madeira Island has an intense aroma easily distinguishable from other tangerines, being traditionally used to enrich several foods and beverages. Nonetheless, setubalense volatile composition has never been characterized, and we aimed to unveil the bioactive potential of peels and juices of setubalense tangerines and compare them with the murcott variety grown in Portugal mainland. Using headspace solid-phase microextraction coupled to gas chromatography mass spectrometry (HS-SPME/GC-MS), we identified a total of 128 volatile organic metabolites (VOMs) in the juice and peels, with d-limonene, γ-terpinene, β-myrcene, α- and β-pinene, o-cymene, and terpinolene, the most dominant in both cultivars. In contrast, setubalense juices are richer in terpenes, many of them associated with health protection. Discriminant analysis revealed a pool of VOMs, including β-caryophyllene and E-ocimene, with bioactive properties able to differentiate among tangerines according to variety and sample type (peel vs. juice). This is the first report on the volatile composition of setubalense tangerines grown on Madeira Island revealing that its pungent aroma is constituted by secondary metabolites with specific aroma notes and health properties. This is strong evidence of the higher nutraceutical value of such fruit for the human diet.

The Impact of Herbal Infusion Consumption on Oxidative Stress and Cancer: The Good, the Bad, the Misunderstood

The release of reactive oxygen species (ROS) and oxidative stress is associated with the development of many ailments, including cardiovascular diseases, diabetes and cancer. The causal link between oxidative stress and cancer is well established and antioxidants are suggested as a protective mechanism against cancer development. Recently, an increase in the consumption of antioxidant supplements was observed globally. The main sources of these antioxidants include fruits, vegetables, and beverage. Herbal infusions are highly popular beverages consumed daily for different reasons. Studies showed the potent antioxidant effects of plants used in the preparation of some herbal infusions. Such herbal infusions represent an important source of antioxidants and can be used as a dietary protection against cancer. However, uncontrolled consumption of herbal infusions may cause toxicity and reduced antioxidant activity. In this review, eleven widely consumed herbal infusions were evaluated for their antioxidant capacities, anticancer potential and possible toxicity. These herbal infusions are highly popular and consumed as daily drinks in different countries. Studies discussed in this review will provide a solid ground for researchers to have better understanding of the use of herbal infusions to reduce oxidative stress and as protective supplements against cancer development.

An Off-Line DPPH-GC-MS Coupling Countercurrent Chromatography Method for Screening, Identification, and Separation of Antioxidant Compounds in Essential Oil

Essential oils are an important source of natural antioxidants and multiple methods have been established for evaluation of their overall antioxidant activity, however, the antioxidant activities of their compounds are less investigated. In the present study, the hyphenation of 2,2′-diphenyl-1-picrylhydrazyl (DPPH)-gas chromatography (GC)-mass spectrometry (MS) offline and high-speed countercurrent chromatography (HSCCC) is established for efficient screening, identification, and isolation of antioxidants from essential oils and applied to the essential oil of Curcuma wenyujin Y.H. Chen et C. Ling. Five compounds are preliminarily screened as antioxidants using DPPH-GC according to the reduction of GC peak areas of each compound after reaction with DPPH and then identified as eucalyptol (7.66%), camphor (2.34%), δ-elemene (1.15%), β-elemene (7.10%), and curzerene (15.77%) using GC-MS. Moreover, these five compounds are isolated by HSCCC using two solvent systems, n-hexane-acetonitrile-ethanol (5:3:2, v/v) and n-hexane-acetonitrile-acetone (4:3:1, v/v), and subjected to DPPH scavenging assay. Camphor, δ-elemene, and β-elemene show weak DPPH scavenging activity, while curzerene and eucalyptol show moderate DPPH scavenging activity. Notably, a significant synergistic effect on DPPH scavenging is found between curzerene and eucalyptol. The result demonstrated that off-line DPPH-GC-MS coupling CCC is an efficient method for screening, identification, and separation of antioxidant compounds in essential oil

Antioxidant compound screening and chemical composition of sweet ginger (Alpinia coriandriodora D. Fang) essential oil and the mechanism of scavenging radicals

The chemical components of an edible spice, sweet ginger (Alpinia coriandriodora D. Fang) essential oil (AEO) were identified by an ultra-fast gas chromatography electronic nose (E-nose) and the main components were β-pinene (27.9%), 1,8-cineole (17.3%), p-cymene (13.5%), camphene (7.3%), myrcene (5.4%), and pseudolimonene (4.3%). The antioxidant activity of each component was evaluated and the mechanisms of scavenging free radical were studied by E-nose combined with chemical methodology. Decanal and α-copaene in AEO showed strong scavenging activities against DPPH radical, and the scavenging rates were over 85%. Decanal had a strong scavenging activity for ABTS radical and the scavenging rate was more than 60%. Similarly, terpinen-4-ol and eugenol had strong scavenging abilities to OH radical and the scavenging rates were more than 50%. Gas chromatography-mass spectrography results showed that it was feasible to identify the chemical components of essential oil by E-nose, and the similarity reached 88.9%. PRACTICAL APPLICATIONS: Many essential oils have antioxidant activities and can be used in functional foods. In the present work, the antioxidant active components in AEO were identified and screened by ultra-fast GC E-nose. We aimed to target the components with strong antioxidant activity quickly and efficiently through the analysis of the reaction process of DPPH, ABTS and OH radicals with a high scavenging rate in a short time. These results indicate that ultra-fast GC E-nose can be used to screen the antioxidant active components in the essential oil.

The Essential Oil of Salvia rosmarinus Spenn. from Italy as a Source of Health-Promoting Compounds: Chemical Profile and Antioxidant and Cholinesterase Inhibitory Activity

The chemical composition of the essential oil from Salvia rosmarinus Spenn. collected in Calabrian Ionian (R1) and Tyrrhenian (R2) coast (Southern Italy) was examined by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Essential oils are mainly characterized by monoterpene hydrocarbons (39.32-40.70%) and oxygenated monoterpenes (36.08-39.47%). The 1,8-cineole, α-pinene, camphor, and trans-caryophyllene are the most representative compounds. S. rosmarinus essential oils were investigated for their antioxidant activity by using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferric reducing ability power (FRAP), and β-carotene bleaching tests. Additionally, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity assays were used to screen the neuroprotective effects of S. rosmarinus. R2 showed the highest antioxidant potential as confirmed by relative antioxidant capacity index (RACI) and exhibited a selective activity against AChE (half maximal inhibitory concentration, IC50, value of 41.86 μg/mL). These results suggest S. rosmarinus essential oil as a potential source of bioactive compounds.