Accurate determination of volatile-flavor components in bos grunniens milk by high-throughput dynamic headspace gas chromatographic-mass spectrometry

Analysis for different flavor compounds in mature milk from human and livestock animals by GC × GC-TOFMS

Breast milk plays a crucial role in the taste development of infants, which cannot be replicated by other mammalian milk or formulas. This study aimed to identify and characterize the flavor substances in 15 different types of milk and analyze the differences among them. The results showed that human milk contained high levels of esters, particularly fatty acid ethyl esters, which contribute to its unique flavor. The four substances that had the highest flavor contribution in all species were identified as 2,3-butanedione, trimethylamine, isophorone, and acetaldehyde. Furthermore, the analysis of differences revealed that thermal-oxidation of lipids could explain the variation between human milk and other species in terms of flavor compounds. The key differential flavor compounds identified in milk from all species were trimethylamine, propanal, 1-pentanol, pyridine 2-methyl, and 2-butanone. These findings can potentially aid in developing formulas that better meet the taste needs of infants.

HS-GC-IMS Analysis of Volatile Organic Compounds in Different Varieties and Harvesting Times of Rhizoma gastrodiae (Tian Ma) in Yunnan Province

Headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) coupled with principal component analysis (PCA) was used to investigate the differences in volatile organic compounds (VOCs) in four different varieties of Yunnan Huang Tian Ma (containing both winter and spring harvesting times), Yunnan Hong Tian Ma, Yunnan Wu Tian Ma, and Yunnan Lv Tian Ma. The results showed that the flavor substances of different varieties and different harvesting times of Rhizoma gastrodiae were mainly composed of aldehydes, alcohols, ketones, heterocycles, esters, acids, alkenes, hydrocarbons, amines, phenols, ethers, and nitrile. Among them, the contents of the aldehydes, alcohols, ketones, and heterocyclic compounds are significantly higher than those of other substances. The results of cluster analysis and fingerprint similarity analysis based on principal component analysis and Euclidean distance showed that there were some differences between different varieties of Yunnan Rhizoma gastrodiae and different harvesting times. Among them, Yunnan Lv Tian Ma and Wu Tian Ma contained the richest volatile components. Winter may be the best harvesting season for Tian Ma. At the same time, we speculate that the special odor contained in Tian Ma should be related to the aldehydes it is rich in, especially benzene acetaldehyde, Benzaldehyde, Heptanal, Hexanal, Pentanal, and butanal, which are aldehydes that contain a strong and special odor and are formed by the combination of these aldehydes.

Differences in Volatile Organic Compounds in Rhizoma gastrodiae (Tian Ma) of Different Origins Determined by HS-GC-IMS

Headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS) and principal component analysis (PCA) were used to compare the differences in volatile organic compounds (VOCs) of Rhizoma gastrodiae (Tian Ma) from six different origins in Yunnan, Sichuan, Shaanxi, Anhui, Hubei, and Guizhou. A total of 161 signal peaks were identified, and 84 compounds were characterized, including 23 aldehydes, 19 alcohols, 12 ketones, 8 heterocyclic compounds, 7 esters, 4 phenols, 4 acids, 4 ethers, 2 amines, and 1 alkane. The results of cluster analysis and fingerprint similarity analysis based on principal component analysis and Euclidean distance indicated that there were significant differences between the volatile components of Rhizoma gastrodiae from different origins. This study demonstrated that HS-GC-IMS is simple, rapid, accurate, and has a small sample size and can achieve rapid analysis of the differences in volatile compounds between samples of different origins of Rhizoma gastrodiae.

Strategies for studying in vivo biochemical formation pathways and multilevel distributions of sulfanilamide metabolites in food (2012-2022)

Sulfonamide metabolites are a major source of food pollution worldwide. However, the formation of internal sulfanilamide metabolites has only been investigated for selected compounds. In this paper, the fragmentation mechanism and characteristic ions of sulfonamide metabolites are reviewed using density functional theory and Q-Orbitrap high-resolution mass spectrometry. The result of the protonation site, rearrangement and bond breaking induced fragmentations at C₆H₆NO₂S⁺m/z 156.01138, C₆H₆NO⁺m/z 108.04439, and C₆H₆N⁺m/z 92.04948. Mass shifts are calculated for derivative metabolites, including hydrogenation, acetylation, oxidation, glucosylation, glucosidation, sulfation, deamination, formylation, desulfonation and O-aminomethylation. Given their homologous series, it is demonstrated that similar metabolic reactions occur for all sulfonamides. The suspicious sulfonamide metabolites are confirmed by d-labelling experiments and reference standards. This is the first review of the latest advances in the field of sulfonamide metabolite prediction (2012-2022), and scheme design for metabolite multirresidue screening, as well as the challenges in the mass spectrometry evolution.

Comparison of Different Drying Methods for Asparagus [Asparagus cochinchinensis (Lour.) Merr.] Root Volatile Compounds as Revealed Using Gas Chromatography Ion Mobility Spectrometry

Asparagus [Asparagus cochinchinensis (Lour.) Merr.] is a traditional herbal medicine plant commonly used to nourish yin, moisten dryness, and clear fire cough symptoms. Drying is an excellent option to conserve food materials, i.e., grains, fruits, vegetables, and herbs, reducing the raw materials volume and weight. This study aims to evaluate different drying approaches that could increase the value of asparagus, particularly as an ingredient in fast foods or as nutraceutical byproducts. The volatile components of asparagus roots were analyzed by using headspace-gas chromatography-ion mobility spectroscopy under different drying conditions, i.e., natural drying (ND) at ambient air temperature in the dark, well-ventilated room, temperature range 28-32°C, blast or oven drying at 50°C, heat pump or hot-air drying at temperature 50°C and air velocity at 1.5 ms-1 and vacuum freeze-drying at the temperature of -45°C and vacuum pressure of 10-30 Pa for 24 h. The findings revealed that the various drying processes had multiple effects on the color, odor index, and volatile compounds of the asparagus roots. As a result of the investigations, multiple characteristics of components, therefore, exploitation and comparison of various flavors; a total of 22 compounds were identified, such as alcohols, ketones, aldehydes, acids, esters, heterocyclic, and terpene. The present findings may help understand the flavor of the processed asparagus roots and find a better option for drying and processing.

Multivariate Optimization Procedure for Dynamic Headspace Extractions Coupled to GC(×GC)

Volatile organic compounds (VOCs) are ubiquitous chemicals of great interest in the study of aromas and flavours of foods. Many recent studies present optimized headspace (HS) and dynamic headspace (DHS) methods for specific sample types; however, the literature does not present ­(to the best of our knowledge) a generalized procedure for the thorough optimization of a DHS extraction. This article presents an approach using design of experiments (DoE) for the optimization of DHS extraction parameters. The approach is demonstrated for two different food sample types with diverse populations of VOCs: active sourdough colony as an example with a high moisture content, and sourdough bread as an example with a lower moisture content. Optimized methods are assessed for VOC extraction reproducibility and exhaustiveness; guidelines for DHS optimization are presented.

Molecular cloning, expression and anti-tumor function analysis of yak IFITM2 gene

IFITM2 is interferon-induced transmembrane protein 2, which plays an extremely key role in anti-tumor and anti-virus diseases. In this study, the 602 bp cDNA sequence of the yak (Bos grunniens) IFITM2 (BgIFITM2) gene was obtained. Moreover, the prokaryotic expression vector of BgIFITM2 protein was constructed and expressed successfully, with a molecular weight of 33.680 kDa. The proliferation activities and migration abilities of HepG2 cells were significantly inhibited after treatment with BgIFITM2 protein (0.1 and 1 μg/mL) (P < 0.05). The expressions of B cell lymphoma-2 (BCL2)/BCL2-associated X (BAX) and molecular target of rapamycin (mTOR) genes were significantly decreased, but the expressions of BAX gene were significantly increased after treatment with BgIFITM2 protein (0.1 and 1 μg/mL) (P < 0.05). The expression of BAX protein was also significantly increased after treatment with 1 μg/mL BgIFITM2 protein (P < 0.05). Finally, the addition of BgIFITM2 protein attenuated the formation of tumor lesions in mice, and the pathological damage of the lung was less than that in the model group. The expression of Ki67 protein in the model group was significantly higher than that in the control group (P < 0.05), but the expression of Ki67 protein in the BgIFITM2 group was significantly lower than that in the model group (P < 0.05). Taken together, BgIFITM2 protein could inhibit the proliferative activity of HepG2 cells by regulating apoptosis-related genes, and reduce the invasiveness of HepG2 cells in mice lung tissue. These results facilitate further studies on the function of BgIFITM2 protein.

Analysis of Volatile Organic Compounds by HS-GC-IMS in Powdered Yak Milk Processed under Different Sterilization Conditions

Headspace-gas chromatography-ion mobility spectroscopy (HS-GC-IMS) was used to detect the volatile organic compounds (VOCs) of yak milk powders (YMPs) under ultra-high-pressure sterilization (UHPS) and thermization (TH) methods. The analyses led to the identification of several characteristic of compounds, therefore, exploitation and comparison of the different flavors. A total of 46 peaks were detected, and 17 compounds were identified, including 7 aldehydes, 5 ketones, 3 acids, 1 terpene, and 1 ester. Furthermore, principal component analysis (PCA) and fingerprint similarity analysis based on Euclidean distance compared the YMPs and found that the YMPs had certain differences, which can distinguish the YMPs with different sterilization methods. In conclusion, different sterilization methods possibly affect the flavor of YMPs, and UHPS is bettedslfr than TH. Also, aldehydes were mainly be detected in UHPS groups, whereas the ketones and acids mostly appeared in TH groups. Most importantly, UHPS can retain the original flavor of yak milk to a greater extent.

Molecular characterization, expression and functional analysis of yak IFITM3 gene

IFITM3 is interferon-induced transmembrane 3, which plays an extremely key role in anti-proliferation, anti-virus and anti-tumor diseases. In this study, the yak (Bos grunniens) IFITM3 (BgIFITM3) gene contained a 5'-untranslated region (UTR) (25 bp), a coding region (441 bp), and a 3'-UTR (115 bp). The expression of BgIFITM3 gene in liver was significantly higher than that in heart, spleen, lung and kidney (P < 0.01). BgIFITM3 protein was localized on the yak hepatocyte plasma membrane, and its expression was significantly different between 1 day and 15 months of age (P < 0.05). Moreover, the prokaryotic expression vector of BgIFITM3 protein was constructed and expressed successfully, with a molecular weight of 19.5 kDa. The activities of yak hepatocyte were significantly inhibited after treating with BgIFITM3 protein (10 and 20 μg/mL) (P < 0.01). The expression levels of ERBB-2, IRS-1, PI3KR-1, AKT-1 and MAPK-3 were significantly lower after treating with 20 μg/mL BgIFITM3 protein (P < 0.05). Besides, the activities of HepG2 cells were significantly inhibited after treating with BgIFITM3 protein (1, 10 and 20 μg/mL) (P < 0.05). While, the cloning ability and migration ability of HepG2 cells were significantly inhibited after treating with 10 μg/mL BgIFITM3 protein (P < 0.05). Finally, the mitochondria of HepG2 cells was concentrated, cristae widened, and the double film density of mitochondria was increased after treating with 10 μg/mL BgIFITM3 protein. After 10 μg/mL BgIFITM3 protein treating, the expression levels of VDAC-2, VDAC-3 and p53 genes were significantly increased, but the expression level of GPX-4 gene was significantly decreased (P < 0.01). Taken together, the BgIFITM3 protein could inhibit the proliferations of yak hepatocyte and HepG2 cells by regulating the PI3K/Akt pathway or ferroptosis-related genes, respectively. These results benefit for further study of the function of BgIFITM3 protein.