Composition and distribution of α-dicarbonyl compounds in propolis from different plant origins and extraction processing

Construction of Guanidinium-Functionalized Covalent Organic Frameworks via Phototriggered Click Reaction as a Dual-Mode Accurate Sensor for Malondialdehyde

Malondialdehyde (MDA) serves as a pivotal indicator to estimate the lipid peroxidation status and as a biomarker for the assessment of oxidative stress and screening of disease by people excretion. However, most of the existing analytical methods for MDA suffer from complicated derivation, leading to poor accuracy and inconvenience. In this work, the guanidinium-functionalized covalent organic framework (COF) was delicacy-designed and used to tune the modular structure by the building blocks with condensation, phototriggered click reaction, and further guanidylation process. A methoxy-group-containing linker in the skeleton was adopted to form lone-pair delocalized oxygen atoms, trigger the resonance effect, attenuate the polarization of the C═N bond linkages, and weaken the interlayer repulsion, supporting the stability of the guest gating COF. The available guanidino groups grew from the ordered pore walls of the COF and served as the customized talon with an enhanced interaction site density to rapidly grab the target guest by charge-assisted strong hydrogen bonds and electrostatic attraction forces. This distinctive feature significantly bolstered sensitive signal transduction, enabling rapid MDA sensing (within 120 s) without derivation treatment, and achieved a calculated limit of detection (LOD) as low as 0.08 μM. With the accessible image-data transmission process, the portable dual-channel sensing platform achieved sensitive and accurate MDA monitoring.

Advances of nanoparticle derived from food in the control of α-dicarbonyl compounds-A review

α-Dicarbonyl compounds (α-DCs) are predominantly generated through the thermal processing of carbohydrate and protein-rich food. They are pivotal precursors to hazard formation, such as advanced glycation end products (AGEs), acrylamide, and furan. Their accumulation within the body will be genotoxicity and neurotoxicity. Recently, significant advancements have been made in nanotechnology, leading to the widespread utilization of nanomaterials as functional components in addressing the detrimental impact of α-DCs. This review focuses on the control of α-DCs through the utilization of nanoparticle-based functional factors, which were prepared by using edible components as resources. Four emerging nanoparticles are introduced including phenolic compounds-derived nanoparticle, plant-derived nanoparticle, active peptides-derived nanoparticle, and functional minerals-derived nanoparticle. The general control mechanisms as well as the recent evidence pertaining to the aforementioned aspects were also discussed, hoping to valuable helpful references for the development of innovative α-DCs scavengers and identifying the further scope of research.

Evaluating Biological Properties of Stingless Bee Propolis

The aim of the present study was to determine the content of phenolics, flavonoids and tannins, as well as the biological functions of propolis extracts from the stingless bee (Heterotrigona itama). The raw propolis was extracted via maceration with ultrasonic pretreatment in 100% water and 20% ethanol. The yield of ethanolic propolis extracts was about 1% higher than its aqueous counterpart. The colorimetric assays showed that the ethanolic propolis extract had about two times higher phenolics (17.043 mg GAE/g) and tannins (5.411 mg GAE/g), and four times higher flavonoids (0.83 mg QE/g). The higher phenolic content had enhanced the antiradical and antibacterial capacities of the ethanolic extract. The propolis extracts significantly exhibited higher antibacterial activity against gram-positive bacteria (Staphylococcus aureus) than gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa). However, aqueous extract was found to have a higher anticancer property based on the viability of lung cancer cells. No cytotoxic effect was observed on normal lung cells as the cell viability was maintained >50%, even the concentration of propolis extracts were increased up to 800 µg/mL. Different chemical compositions of propolis extract would show different bioactivities depending upon the individual applications. The high content of phenolics suggests that the propolis extract could be a natural source of bioactive ingredients for the development of innovative and functional foods.

Chaste honey in long term-storage: Occurrence and accumulation of Maillard reaction products, and safety assessment

Honey, a natural sweetener that can be stored long-term, is prone to Maillard reactions. Maillard reaction products (MRPs), such as 5-hydroxymethylfurfural (5-HMF), α-dicarbonyl compounds (α-DCs), and advanced glycation end products (AGEs), negatively affect human health. We analyzed MRP accumulation in chaste honey over four years. In the first year, α-DCs were dominant with total contents of 509.7 mg/kg. In the second year, Amadori compounds increased, accounting for the largest percentage. Their formation at the initial stage showed inhibition of the Maillard reaction over time. AGE contents were approximately 1.00 mg/kg over four years, which is negligible compared to other foods. Increased 5-HMF was significantly correlated with storage time (p < 0.01), making it a suitable indicator of honey quality. Due to the lack of MRP risk assessments, we compared our findings with daily intake of MRPs from other foods, and the levels of MRPs in honey over four years are acceptable.