A new method has been developed for measuring the D/H ratio of the nonexchangeable sites of citric acid by isotope ratio mass spectrometry (IRMS). Pure citric acid is transformed into its calcium salt and subsequently analyzed by pyrolysis-IRMS. The citric acid isolated from authentic fruit juices (citrus, pineapple, and red fruits) systematically shows higher D/H values than its nonfruit counterpart produced by fermentation of various sugar sources. The discrimination obtained with this simplified method is similar to that obtained previously by applying site specific isotopic fractionation-nuclear magnetic resonance (SNIF-NMR) to an ester derivative of citric acid. The combination of carbon 13 and deuterium measurements of extracted citric acid is proposed as a routine method for an optimum detection of exogenous citric acid in all kinds of fruit juices.
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http://dx.doi.org/10.1021/jf050400b | DOI Listing |
Sci Rep
January 2025
Chemistry Department, Faculty of Science, Menoufia University, Shibin El-Kom, 32511, Egypt.
In this work, microalgae-based zinc oxide nanoparticles loaded with electrospun polyvinyl alcohol (PVA)/sodium alginate (SA) nanofibers were fabricated by electro-spinner. PVA/SA fibrous mats were crosslinked by citric acid, which enhanced their thermal stability and swelling behavior. Green-synthesized ZnO NPs were laboratory synthesized and characterized by FTIR, XRD, EDX, SEM, TEM and TGA analyses.
View Article and Find Full Text PDFAcc Chem Res
January 2025
Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
ConspectusReactions of gas phase molecules with surfaces play key roles in atmospheric and environmental chemistry. Reactive uptake coefficients (γ), the fraction of gas-surface collisions that yield a reaction, are used to quantify the kinetics in these heterogeneous and multiphase systems. Unlike rate coefficients for homogeneous gas- or liquid-phase reactions, uptake coefficients are system- and observation-dependent quantities that depend upon a multitude of underlying elementary steps.
View Article and Find Full Text PDFJ Biomed Mater Res B Appl Biomater
January 2025
Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, People's Republic of China.
In dental implant surgery, infection is identified as the primary factor contributing to the failure of bone grafts. There is an urgent need to develop bone graft materials possessing antibacterial characteristics to facilitate bone regeneration. Magnesium phosphate bone cement (MPC) is highly desirable for bone regeneration due to its favorable biocompatibility, plasticity, and osteogenic capabilities.
View Article and Find Full Text PDFJ Dairy Res
January 2025
Facultad de Ingeniería Química (FIQ-UNL), Instituto de Lactología Industrial (CONICET), Santiago del Estero 2829, Santa Fe, Argentina.
We compared the effects of two waste-based culture media (M1 and M2) on the technological properties of (L90) for its application as a secondary culture in Cremoso cheese. The following parameters were studied at different ripening times: pH (7, 20, and 40 d), microbiological counts, carbohydrates and organic acids (7 and 40 d), moisture, fat, protein and volatile compounds (40 d). The viability and the metabolic performance of the strain in cheeses were also verified along ripening.
View Article and Find Full Text PDFPhytochem Anal
January 2025
College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, China.
Introduction: As a widely used Chinese herbal medicine, Mume Fructus pulp (MFP) has rich nutritional value and biological activity, but its quality control research is relatively scarce.
Objectives: The objective of the study was to evaluate the quality difference between MFPs from different origins and its adulterant apricot pulp (APP), and to identify potential quality markers.
Methods: The chemical compositions were identified by untargeted metabolomics analysis based on ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry combined with feature-based molecular networking.
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