Determination of glyoxal, methylglyoxal, and diacetyl in red ginseng products using dispersive liquid-liquid microextraction coupled with GC-MS.

A simple and rapid dispersive liquid-liquid microextraction method coupled with gas chromatography and mass spectrometry was applied for the determination of glyoxal as quinoxaline, methylglyoxal as 2-methylquinoxaline, and diacetyl as 2,3-dimethylquinoxaline in red ginseng products. The performance of the proposed method was evaluated under optimum extraction conditions (extraction solvent: chloroform 100 µL, disperser solvent: methanol 200 µL, derivatizing agent concentration: 5 g/L, reaction time: 1 h, and no addition of salt). The limit of detection and limit of quantitation were 1.30 and 4.33 µg/L for glyoxal, 1.86 and 6.20 µg/L for methylglyoxal, and 1.45 and 4.82 µg/L for diacetyl. The intra- and interday relative standard deviations were <4.95 and 5.80%, respectively. The relative recoveries were 92.4-103.9% in red ginseng concentrate and 99.4-110.7% in juice samples. Red ginseng concentrates were found to contain 191-4274 µg/kg of glyoxal, 1336-4798 µg/kg of methylglyoxal, and 0-830 µg/kg of diacetyl, whereas for red ginseng juices, the respective concentrations were 72-865, 69-3613, and 6-344 µg/L.

Solid-phase microextraction Arrow for the volatile organic compounds in soy sauce.

A novel solid-phase microextraction Arrow was used to separate volatile organic compounds from soy sauce, and the results were verified by using gas chromatography with mass spectrometry. Solid-phase microextraction Arrow was optimized in terms of three extraction conditions: type of fiber used (polydimethylsiloxane, polyacrylate, carbon wide range/polydimethylsiloxane, and divinylbenzene/polydimethylsiloxane), extraction temperature (40, 50, and 60°C), and extraction time (10, 30, and 60 min). The optimal solid-phase microextraction Arrow conditions were as follows: type of fiber = polyacrylate, extraction time = 60 min, and extraction temperature = 50°C. Under the optimized conditions, the solid-phase microextraction Arrow was compared with conventional solid-phase microextraction to determine extraction yields. The solid-phase microextraction Arrow yielded 6-42-fold higher levels than in solid-phase microextraction for all 21 volatile organic compounds detected in soy sauce due to the larger sorption phase volume. The findings of this study can provide practical guidelines for solid-phase microextraction Arrow applications in food matrixes by providing analytical methods for volatile organic compounds.

Dispersive liquid-liquid microextraction with in situ derivatization coupled with gas chromatography and mass spectrometry for the determination of 4-methylimidazole in red ginseng products containing caramel colors.

A rapid analytical method was developed for the determination of 4-methylimidazole from red ginseng products containing caramel colors by using dispersive liquid-liquid microextraction with in situ derivatization followed by gas chromatography with mass spectrometry. Chloroform and acetonitrile were selected as the extraction and dispersive solvents, and based on the extraction efficiency, their optimum volumes were 200 and 100 µL, respectively. The optimum volumes of the derivatizing agent (isobutyl chloroformate) and catalyst (pyridine), pH, and concentration of NaCl in the sample solution were determined to be 25 and 100 µL, pH 7.6, and 0% w/v, respectively. Validation of the optimized method showed good linearity (R2  > 0.999), accuracy (≥89.86%), intra- (≤6.70%) and interday (≤4.17%) repeatability, limit of detection (0.96 µg/L), and limit of quantification (5.79 µg/L). The validated method was applied to quantify 4-methylimidazole in red ginseng juices and concentrates, 4-methylimidazole was only found in red ginseng juices containing caramel colorant (42.91-2863.4 µg/L) and detected in red ginseng concentrates containing >1% caramel colorant.

Headspace stir-bar sorptive extraction combined with gas chromatography-mass spectrometry for trace analysis of volatile organic compounds in Schisandra chinensis Baillon (omija).

Analyzing volatile organic compounds (VOCs) in food is crucial but challenging. Schisandra chinensis Baillon (omija) is an herbal plant with various functional health activities. Previous VOC analyses focused on S. chinensis fruit but not its leaves. Therefore, VOCs in S. chinensis fruit and leaves were analyzed using headspace stir-bar sorptive extraction (HS-SBSE)-GC-MS, and optimal conditions were established. Various factors, such as the sample preparation method, twister stir-bar type, sample amount, extraction temperature, and extraction time, expected to affect extraction were carefully optimized. Under the optimal conditions, 35 and 40 VOCs were identified in S. chinensis fruit and leaves, respectively. This HS-SBSE method is capable of rapid analysis and a low contamination rate without requiring organic solvents. These findings provide practical guidelines for HS-SBSE applications in various food matrices by providing analytical methods for VOC detection.

Chemical Composition, Antioxidant, and Anti-Inflammatory Activity of Essential Oil from Omija (Schisandra chinensis (Turcz.) Baill.) Produced by Supercritical Fluid Extraction Using CO2.

Schisandra chinensis (Turcz.) Baill., which is known as omija in South Korea, is mainly cultivated in East Asia. The present study aimed to investigate the chemical composition of essential oil from the omija (OMEO) fruit obtained by supercritical fluid extraction using CO2 and to confirm the antioxidant and anti-inflammatory activity of OMEO using HaCaT human keratinocyte and RAW 264.7 murine macrophages. As a result of the chemical composition analysis of OMEO using gas chromatography-mass spectrometry, a total of 41 compounds were identified. The detailed analysis results are sesquiterpenoids (16), monoterpenoids (14), ketones (4), alcohols (3), aldehydes (2), acids (1), and aromatic hydrocarbons (1). OMEO significantly reduced the increased ROS levels in HaCaT keratinocytes induced by UV-B irradiation (p < 0.05). It was confirmed that 5 compounds (α-pinene, camphene, ß-myrcene, 2-nonanone, and nerolidol) present in OMEO exhibited inhibitory activity on ROS production. Furthermore, OMEO showed excellent anti-inflammatory activity in RAW 264.7 macrophages induced by lipopolysaccharide. OMEO effectively inhibited NO production (p < 0.05) by suppressing the expression of the iNOS protein. Finally, OMEO was investigated for exhibition of anti-inflammatory activity by inhibiting the activation of NF-κB pathway. Taken together, OMEO could be used as a functional food ingredient with excellent antioxidant and anti-inflammatory activity.

Quality characteristics of duck jerky: combined effects of collagen and konjac.

The effects of curing solution prepared using various ratios of a combination of collagen and konjac (100/0, 80/20, 60/40, 40/60, 20/80, and 0/100) on the quality characteristics of duck jerky were investigated. The moisture, processing yield, water activity, tenderness score, and overall acceptability score of duck jerky were the highest when the ratio of added collagen and konjac was 60/40. The rehydration ratio of duck jerky increased due to the addition of collagen and konjac combinations in curing solution, and was higher for the 60/40 and 40/60 combinations than for the others. The shear force of duck jerky was the highest for the untreated jerky, and the lowest for the jerky formulated with the 60/40 combination of collagen and konjac solution. No significant differences were observed in lightness and yellowness between jerky treated with combinations of collagen and konjac. Taken together, our results indicate that addition of a combination of collagen and konjac at a 60/40 ratio results in good quality characteristics of duck jerky. Thus, we suggest that the use of combinations of collagen and konjac in duck jerky processing is beneficial for improving the quality characteristics of the jerky.

Instrumental volatile flavor analysis of omija (Schisandra chinesis Baillon) using headspace stir-bar sorptive extraction-gas chromatography-mass spectrometry and its relationship to human sensory perceptions.

Omija (Schisandra chinesis Baillon) is a cluster of berries, mainly cultivated in East Asian countries. The objective of this study was to conduct an instrumental volatile flavor analysis and descriptive analysis of omija samples using headspace stir-bar sorptive extraction gas chromatography-mass spectrometry. Three omija fruits were included and pre-treated using three different methods: frozen omija (FO), frozen-blended omija (FBO), and freeze-dried omija (FDO). A total of 28 volatiles were identified, and significant differences in concentrations found among omija samples were noted, especially for previously identified aroma-active compounds such as α-pinene, α-terpinene, and (E)-ß-ocimene (p < .05). In terms of sensory perception, significant differences were observed in three sensory attributes that included, ginger, pine needle, and wet grassy aromatics among the samples (p < 0.05). While similarities and dissimilarities were observed among the three samples in the instrumental flavor analysis results, a principal component analysis revealed that FBO and FDO shared similar flavor characteristics while FO had distinctive flavor characteristics.

Determining pesticide residues in wheat flour by ultrahigh-performance liquid chromatography/quadrupole time-of-flight mass spectrometry with QuEChERS extraction.

Pesticides are used to increase crop yields and preserve quality by protecting crops against pests; however, their overuse can adversely affect human health and the environment. Herein, we report the development of a multi-pesticide screening method using optimized QuEChERS coupled with liquid chromatography/quadrupole time-of-flight (QTOF) mass spectrometry for the analysis of 13 pesticides in wheat flour. Mass accuracies with errors of less than 2.4 ppm were obtained for all analysed pesticides, and the method provided satisfactory recovery and linearity. Repeatabilities of 0.3-12.7% and reproducibilities of 2.5-15.2% were observed in full-scan TOF mode. The performance of the developed full-scan TOF method was compared to that obtained in high-resolution multiple reaction monitoring (MRM-HR) mode. The limits of quantification for the full-scan TOF and MRM-HR modes ranged from 2 to 10, and 3 to 9 µg kg-1, respectively. The two quantification methods exhibited high sensitivities (limit of detections: 1-3 µg kg-1 in full-scan TOF, and 1-3 µg kg-1 for MRM-HR mode). No pesticide residues were detected when the developed method was applied to 22 real wheat flour samples.

Determination of 60 pesticides in hen eggs using the QuEChERS procedure followed by LC-MS/MS and GC-MS/MS.

An analytical method involving QuEChERS (quick, easy, cheap, effective, rugged, and safe) sample preparation, followed by LC-MS/MS and GC-MS/MS was developed and validated for the determination of 60 pesticides in eggs. Recoveries of 70-120% were achieved for selected pesticides and relative standard deviations <20% were obtained for most analytes at three concentrations. The limit of quantification was <10 µg kg-1 for 83% of the total pesticides. This method was used to analyze 58 egg samples and the residues of seven pesticides (disulfoton, fipronil sulfone, cyromazine, o,p-DDT, p,p-DDD, p,p-DDT, and permethrin) were quantified in 16 egg samples at levels of 5-10 µg kg-1, which was below the corresponding the maximum residue levels, as established by Korean Ministry of Food and Drug Safety. We demonstrated that LC-MS/MS and GC-MS/MS in combination with QuEChERS can be used to routinely monitor multiple pesticide residues in egg samples.

Enhancing Immunomodulatory Function of Red Ginseng Through Fermentation Using Bifidobacterium animalis Subsp. lactis LT 19-2.

Removal of sugar moieties from ginsenosides has been proposed to increase their biological effects in various disease models. In order to identify strains that can increase aglycone contents, we performed a screening using bacteria isolated from the feces of infants focusing on acid tolerance and ß-glucosidase activity. We isolated 565 bacteria and selected Bifidobacterium animalis subsp. lactis LT 19-2 (LT 19-2), which exhibited the highest ß-glucosidase activity with strong acid tolerance. As red ginseng (RG) has been known to exert immunomodulatory functions, we fermented RG using LT 19-2 (FRG) and investigated whether this could alter the aglycone profile of ginsenosides and improve its immunomodulatory effect. FRG increased macrophage activity more potently compared to RG, demonstrated by higher TNF-α and IL-6 production. More importantly, the FRG treatment stimulated the proliferation of mouse splenocytes and increased TNF-α levels in bone marrow-derived macrophages, confirming that the enhanced immunomodulatory function can be recapitulated in primary immune cells. Examination of the molecular mechanism revealed that F-RG could induce phosphorylations of ERK, p38, JNK, and NF-κB. Analysis of the ginsenoside composition showed a decrease in Rb1, Re, Rc, and Rb3, accompanied by an increase in Rd, Rh1, F2, and Rg3, the corresponding aglycone metabolites, in FRG compared to RG. Collectively, LT 19-2 maybe used as a probiotic strain to improve the bioactivity of functional foods through modifying the aglycone/glycoside profile.

Comparative studies of bioactive organosulphur compounds and antioxidant activities in garlic (Allium sativum L.), elephant garlic (Allium ampeloprasum L.) and onion (Allium cepa L.).

We evaluated organosulphur compounds in Allium vegetables, including garlic, elephant garlic and onion, using high-performance liquid chromatography. Among organosulphur compounds, elephant garlic had considerable γ-glutamyl peptides, and garlic had the highest alliin content. Onion had low level of organosulphur compounds than did elephant garlic and garlic. In addition, antioxidant capacities were evaluated by oxygen radical absorbance capacity (ORAC) values and 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging assay. The results showed that garlic had the highest antioxidant capacity, followed by elephant garlic and onion. Furthermore, a positive correlation was observed between antioxidant activities and organosulphur compounds (R > 0.77). Therefore, our results indicate that there was a close relationship between antioxidant capacity and organosulphur compounds in Allium vegetables.