Exploring formation of turanose in honey via stable isotope labelling and high-resolution mass spectrometry analysis.

Turanose, an isomer of sucrose, naturally exists in honey. Previous study indicated that turanose content increased gradually in acacia honey as honeybees brewed honey in the hive. However, it is unclear how turanose is generated in honey. We hypothesised that turanose was produced by enzymes from honeybees and performed a series of simulation experiments to prove this hypothesis. We found turanose in honey was produced by honeybees processing sucrose. Furthermore, we determined that sugar composition of simulated nectar influenced the turanose concentration in honey: when sucrose concentration was below 5%, turanose was difficult to form, whereas high concentration of fructose and limited glucose were beneficial in producing turanose. Using 13C-labelled sucrose tests combined with proteomics analysis, we identified that α-glucosidase converted sucrose to turanose through an intermolecular isomerisation process. This study reveals the formation mechanism of turanose in honey and assists in the scientific control and improvement of honey quality.

Exploring the Formation of Chemical Markers in Chaste Honey by Comparative Metabolomics: From Nectar to Mature Honey.

Identification of chemical markers is important to ensure the authenticity of monofloral honey; however, the formation of chemical markers in honey has received little attention. Herein, using comparative metabolomics, we first identified chemical markers in chaste honey and then explored their formation and accumulation from nectar to mature honey. We identified agnuside and p-hydroxybenzoic acid glucosides as chemical markers for chaste honey. Besides, we developed an UHPLC-MS/MS method for quantifying these markers and found that their levels varied significantly across sample sources. We compared the presence of these compounds in chaste nectar and mature honey. The outcomes underscore that these characteristic compounds are not simply delivered from nectar to mature honey, and activities of honeybees (collecting and processing) play a pivotal role in their formation and accumulation. These observations shed light on how mature honey can form its unique qualities with a rich assortment of natural bioactive compounds, potentially supporting health benefits.

Evaluation of next-generation sequencing performance for in vitro detection of viruses in biological products.

Next-Generation Sequencing (NGS) can detect nucleic acid sequences in a massively parallel sequencing. This technology is expected to be widely applied for the detection of viral contamination in biologics. The recently published ICH-Q5A (R2) draft indicates that NGS could be an alternative or supplement to in vitro viral tests. To examine the performance of NGS for the in vitro detection of viruses, adenovirus type 5 (Ad5), a model virus, was inoculated into Vero cells, which are the most popular indicator cells for the detection of adventitious viruses in the in vitro test. Total RNA extracted from the Vero cells infected with Ad5 was serially diluted with that from non-infected Vero cells, and each sample was analyzed using short- or long-read NGSs. The limits of detection of both NGS methods were almost the same and both methods were sensitive enough to detect viral sequences as long as there was at least one copy in one assay. Although the multiplexing in NGS carries the risk of cross-contamination among the samples, which could lead to false positives, this technology has the potential to become a rapid and sensitive method for detecting adventitious agents in biologics.