Metabolite identification was performed using Compound Discoverer 3.1 by matching accurate mass (MS1), retention time, and MS/MS fragmentation spectra against multiple databases, including the BMDB Library (BGI Metabolome Database), mzCloud (high-resolution tandem mass spectrometry cloud database), and ChemSpider (integrated with HMDB, KEGG, and LipidMaps databases). Identification parameters were as follows: precursor mass tolerance < 5 ppm, fragment mass tolerance < 10 ppm, and retention time tolerance < 0.2 min. Metabolites were annotated with KEGG pathway information using the metaX pipeline and the KEGG database (www.genome.jp/kegg). Annotation confidence levels were assigned according to the Metabolomics Standards Initiative (MSI): Level 1 (confirmed by reference standard), Level 2 (putative structure based on MS/MS spectral match), Level 3 (putative compound class), and Level 4 (unknown, accurate mass only).
"],"repository":["MetaboLights"],"study_status":["Public"],"ptm_modification":[""],"instrument_platform":["Liquid Chromatography MS - negative - reverse-phase","Liquid Chromatography MS - positive - reverse-phase"],"chromatography_protocol":["Chromatographic separations were performed on a Waters 2D Ultra Performance Liquid Chromatography (UPLC) system (Waters, USA). The column used was an ACQUITY UPLC BEH C18 column (1.7 μm, 2.1 × 100 mm, Waters, USA), maintained at a column temperature of 45 °C. The flow rate was 0.35 mL/min, and the injection volume was 5 μL. The gradient program was as follows: 0–1 min, 2% B; 1–9 min, 2–98% B; 9–12 min, 98% B; 12–12.1 min, 98–2% B; 12.1–15 min, 2% B.
Mobile phases:
Positive ion mode: Mobile phase A: 0.1% formic acid in water; Mobile phase B: acetonitrile
Negative ion mode: Mobile phase A: 10 mM ammonium formate in water; Mobile phase B: acetonitrile
"],"publication":["Effects of dietary Hermetia illucens oil on rumen and serum metabolome profiles in lactating dairy cows."],"submitter_affiliation":["City University of Hong Kong"],"submitter_name":["Guanglei Liu"],"organism_part":["blood serum"],"technology_type":["mass spectrometry assay"],"disease":[""],"extraction_protocol":["Rumen fluid samples were thawed on ice at 4 °C. Samples were vortexed for 30 s and centrifuged at 13,000 × g for 15 min at 4 °C to remove particulate matter. For each sample, 800 μL of ice-cold extraction solvent (methanol:acetonitrile:water, 2:2:1, v/v/v) containing internal standards (IS1 and IS2) was added. The mixture was homogenized using a TissueLyser (JXFSTPRP, China) for 5 min, sonicated in an ice-water bath for 10 min, and incubated at −20 °C for 1 h. After centrifugation at 25,000 × g for 15 min at 4 °C, the supernatant was collected, lyophilized, and reconstituted in 200 μL of 10% methanol. The final extract was sonicated for 10 min at 4 °C, centrifuged at 25,000 × g for 15 min, and transferred to LC-MS vials for analysis.
A pooled quality control (QC) sample was prepared by mixing equal volumes of each sample to assess the reproducibility of the LC-MS analysis throughout the run. QC samples were injected at regular intervals (every 10 samples) to monitor instrument stability and batch effects. The internal standard mix contained L-Leucine-d3, L-Phenylalanine (13C9, 99%), L-Tryptophan-d5, and Progesterone-2,3,4-13C3. A blank sample (extraction solvent without biological sample) was processed and analyzed to monitor potential contaminants and system background.
"],"organism":["Bos taurus"],"full_dataset_link":["https://www.ebi.ac.uk/metabolights/MTBLS14114"],"author":["Ákos Kenéz. Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Hong Kong SAR, China. akos.kenez@cityu.edu.hk.","Mauro Coppa.","Lara Rastello.","Guanglei Liu. e804289119@gmail.com.","Laura Gasco.","Manuela Renna.","Mathieu Gerbelle."],"data_transformation_protocol":["Raw data files (.raw) were processed using Compound Discoverer 3.1 software (Thermo Fisher Scientific, USA). Data processing steps included peak extraction, retention time correction (within and between groups), adduct ion grouping, missing value filling, background peak labeling, and metabolite identification. After Compound Discoverer processing, the exported data were further preprocessed using the in-house metabolomics R package metaX. Preprocessing steps included normalization using Probabilistic Quotient Normalization (PQN) to obtain relative peak areas, batch effect correction using QC-RLSC (Quality Control-based Robust LOESS Signal Correction), and filtering of compounds with coefficient of variation (CV) > 30% in QC samples.
"],"study_factor":["Treatment"],"submitter_email":["e804289119@gmail.com"],"sample_collection_protocol":["Rumen fluid samples were collected from lactating dairy cows (Bos taurus, Valdostana Red Pied breed) enrolled in a dietary intervention study comparing the effects of fractionated palm oil (FPO) and Hermetia illucens oil (HIO) supplementation. Samples were collected at two time points: day 0 (baseline, prior to dietary intervention) and day 50 (end of the trial). Sampling was conducted immediately after the morning milking and before the morning feeding using a flexible esophageal tube (300 cm in length and 1.9 cm in diameter) equipped with a manual pump (Ammerlaan, Loue, France) connected to a collecting flask (1 L borosilicate glass bottle GLS 80) to ensure a vacuum-sealed environment within the pipeline. The initial 100 mL of rumen fluid was discarded to minimize salivary contamination. Approximately 500 mL of rumen fluid was collected from each cow and filtered through a layer of polyester filter fabric (250 μm mesh aperture; Drenth Holland, Oude Pekela, Netherlands) to remove the substantial part of particulate matter. After filtration, all rumen fluid samples were stored at −80 °C to preserve their integrity for subsequent untargeted metabolomics analysis. An ethanol-water solution (1:1, v/v) was used to thoroughly wash the bottles and polyester layers after each use, ensuring effective cleaning and minimizing potential cross-contamination.
Mass spectrometry was performed using a Q Exactive HF high-resolution mass spectrometer (Thermo Fisher Scientific, USA) equipped with a heated electrospray ionization (HESI) source operating in positive ion mode. The full scan range was 70–1050 m/z with a resolution of 70,000. The automatic gain control (AGC) target was set to 3e6 with a maximum injection time of 100 ms. Data-dependent MS/MS acquisition was performed on the top 3 precursors with a resolution of 30,000, AGC target of 1e5, maximum injection time of 50 ms, and stepped normalized collision energy of 20, 40, and 60 eV. The mass spectrometry settings were as follows: spray voltage, 3.8 kV; sheath gas flow rate, 40 arbitrary units (arb); aux gas flow rate, 10 arb; aux gas heater temperature, 350 °C; capillary temperature, 320 °C.
"],"additional_accession":[]},"is_claimable":false,"name":"Effects of dietary Hermetia illucens oil on rumen and serum metabolome profiles in lactating dairy cows","description":"The metabolomics study was designed to investigate the effects of feeding cows with Hermetia illucens larvae oil on rumen fluid profiles.
","dates":{"publication":"2026-03-24","submission":"2026-03-23"},"accession":"MTBLS14114","cross_references":{}}