Sugars or saccharides exist as structural and stereo- isomers and can be difficult to analyse, due to insufficient analyte separation. By coupling chromatography with mass spectrometry, the reliability of the analysis can be improved, but there is still potential for erroneous results due to the vast array of saccharide isomers present in nature. In this study, we present a method for the analysis of 80 saccharides analysed using an ion chromatograph coupled to a mass spectrometer. The method successfully separated, identified and quantitated 21 monosaccharides, 28 disaccharides, 15 trisaccharides, 7 tetrasaccharides, and 9 sugar alcohols. The feasibility of this method was demonstrated through the analysis of commercially available rare and common sugar samples, as well as honeys. While the method showed promising results for these compounds, further validation will be required to determine its applicability in more stringent fields such as forensics and clinical analysis.

This paper demonstrates the fraction collection of the novel sugar trehalulose, using a modified ion chromatograph. The Ion Chromatography (IC) method, previously published for the analysis of trehalulose, was augmented with a suppressor and purpose-made switching valve unit. A sample of stingless bee honey was then run, following the three main steps:•Separation of trehalulose fraction•Lyophilization•Confirmation of trehalulose The method should be applicable to not only sugar analysis but to any bioactive compound separable by IC. The authors were not able to find a similar method within currently published literature.
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The composition and bioactivity of honey are influenced by its botanical, geographical, and entomological origins. This study investigates the physicochemical characteristics, antioxidant capacity, and antimicrobial activity of stingless bee honey (SBH) produced by three Malaysian stingless bee species: Heterotrigona itama, Lophotrigona canifrons, and Tetrigona binghami. The moisture content ranges from 25.44% to 40.36%, while the honey color varies from light amber to dark amber. The fructose, glucose, and sucrose contents range from 5.45 to 16.91 g/100 g, 3.85 to 19.64 g/100 g, and undetectable to 2.47 g/100 g, respectively. Trehalulose is present at a level of 15.42 to 43.75 g/100 g, with L. canifrons honey exhibiting the highest trehalulose concentration. All samples show low 5-HMF content and no detectable diastase activity. T. binghami honey has the lowest pH, highest electricity conductivity and acidity, and exhibits the strongest antimicrobial activity against Staphylococcus aureus and Escherichia coli. H. itama honey exhibits the highest antioxidant potential based on ABTS, FRAP, and DPPH assays. Among the three species, L. canifrons honey contains the highest total phenolic content. These findings provide valuable insights into the unique properties of SBH, supporting further research, quality assessment, and the development of international standards.

This study investigates the physiochemical properties, chemical composition, and antioxidant activity of Australian stingless bee honey blends from two bee species, Tetragonula carbonaria and Tetragonula hockingsi, harvested in Burpengary East, Queensland at different times of the year. The moisture content of the honey samples ranged from 26.5% to 30.0%, total soluble solids from 70.0 to 73.5° Brix, and pH from 3.57 to 4.19. The main sugars identified were trehalulose (13.9 to 30.3 g/100 g), fructose (12.9 to 32.3 g/100 g), and glucose (4.80 to 23.7 g/100 g). The total phenolic content (TPC), measured using the Folin-Ciocalteu assay, ranged from 26.1 to 58.6 mg of gallic acid equivalents/100 g. The antioxidant activity was investigated with the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, with values ranging from 1.39 to 6.08 mmol of Trolox equivalents/kg. Antioxidant constituents were determined using a High-Performance Thin-Layer Chromatography (HPTLC)-DPPH assay. The HPTLC-DPPH analysis revealed that honey samples collected in May 2022 contained the highest number of antioxidant compounds. Some constituents were identified using an HPTLC-derived database and also quantified utilising HPTLC analysis. Lumichrome was present in all honey samples, while luteolin and kaempferide were detected only in some. Kaempferol or isorhamnetin was also found to be present, although a definitive distinction between these two chemically closely related compounds could not be made by HPTLC analysis. The results showed that honey produced by Tetragonula hockingsi and Tetragonula carbonaria shares similar properties and composition when harvested at the same time, with only minor differences in moisture, fructose, and glucose content.

Under appropriate experimental conditions, some glycoside hydrolases can catalyze transglycosylation reactions; a hypothesis associated with this is that the glycosidic linkages formed will be preferentially hydrolyzed under optimal conditions. Therefore, the hydrolytic and transglycosylation activities of isolated membranes from differentiated Caco-2 cells on sucrose, maltose and isomaltulose were evaluated. After the enzymatic reactions, the di- and trisaccharides obtained were identified by gas chromatography coupled to a mass spectrometer. Differentiated Caco-2 cell membranes exerted hydrolytic and transglycosylation activities towards the studied disaccharides. The obtained di- and trisaccharides were detected for the first time using human cell models. Due to the absence of maltase-glucoamylase complex (MGAM) in Caco-2 cells, and the known hydrolytic activity of sucrase-isomaltase (SI) towards sucrose, maltose and isomaltulose, it is plausible that the glycosidic linkages obtained after the transglycosylation reaction, mainly α-glucosyl-fructoses and α-glucosyl-glucoses, were carried out by SI complex. This approach can be used as a model to explain carbohydrate digestibility in the small intestine and as a tool to design new oligosaccharides with low intestinal digestibility.Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.