Browning seriously causes postharvest deterioration of the yellow cultivars of Flammulina filiformis, yet the browning process and its mechanism have not been described. Changes of L*, a*, b* values, the browning and whiteness index during air contacted storage were evaluated, uncovering the great loss of brightness and meanwhile the accumulation of yellowness and redness. Browning tissue showed an increase of malondialdehyde, total phenolics, and browning-related enzyme activities of polyphenol oxidase and peroxidase, in contrast to the decrease of bioprotective catalase, superoxide, and dismutase. Non-targeted metabolomics revealed an upregulation of melanin synthesis under oxidation stress, and targeted LC-MS/MS verified the upregulation of l-dopa (3,4-dihydroxy-l-phenylalanine) during browning. Pyrrole-2,3,5-tricarboxylic acid was identified in the degradation products of browning pigments after alkaline hydrogen peroxide by LC-MS/MS, suggesting the existence of 5,6-dihydroxyindole-2-carboxylic acid derived units of eumelanin. Therefore, the biosynthesis of eumelanin via l-dopa pathway could participate in the enzymatic browning of postharvest F. filiformis.
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http://dx.doi.org/10.1016/j.foodchem.2021.131295 | DOI Listing |
JACC Cardiovasc Interv
December 2024
Department for Angiology, Brandenburg Medical School Theodor Fontane, Campus Clinic Brandenburg, Center for Internal Medicine I, Berlin, Germany; Department of Angiology, Sankt-Gertrauden-Krankenhaus, Berlin, Germany.
Background: Several randomized clinical trials have shown that the composite endpoint of death, stroke, and myocardial infarction (MI) is equivalent between carotid artery stenting and carotid endarterectomy. However, the risk of minor stroke has been consistently higher with carotid artery stenting.
Objectives: The authors sought to evaluate the safety and effectiveness of a novel carotid stent system comprised of a stent, an adjustable integrated embolic filter and a postdilation balloon, in patients at elevated risk for adverse events from carotid endarterectomy.
BMJ
December 2024
Brown University School of Public Health, Providence, Rhode Island, USA.
FASEB J
January 2025
Department of Radiology, C.J. Gorter MRI Center, Leiden University Medical Center, Leiden, The Netherlands.
Brown adipose tissue (BAT) is a metabolically highly active tissue that dissipates energy stored within its intracellular triglyceride droplets as heat. Others have previously utilized MRI to show that the fat fraction of human supraclavicular BAT (scBAT) decreases upon cold exposure, compared with baseline (i.e.
View Article and Find Full Text PDFArch Dis Child
December 2024
Immunization and Vaccine Preventable Diseases, UK Health Security Agency, London, UK.
J Microsc
January 2025
Department of Mechanical, Materials and Aerospace Engineering, University of Liverpool, Liverpool, UK.
Electron backscatter diffraction (EBSD) has developed over the last few decades into a valuable crystallographic characterisation method for a wide range of sample types. Despite these advances, issues such as the complexity of sample preparation, relatively slow acquisition, and damage in beam-sensitive samples, still limit the quantity and quality of interpretable data that can be obtained. To mitigate these issues, here we propose a method based on the subsampling of probe positions and subsequent reconstruction of an incomplete data set.
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