Enhanced sensitivity in Staphylococcus aureus detection: Unveiling the impact of lipid composition on the performance of carboxyfluorescein (CF)-Loaded liposome-based assay.

Liposomes have emerged as versatile nanocarriers, finding applications not only in drug delivery but also in pathogen detection and diagnostics. This study aimed to enhance the sensitivity of liposomes to Staphylococcus aureus by investigating the impact of lipid composition on liposomes loaded with 5(6)-carboxyfluorescein (CF). Liposomes were fabricated using various concentrations of cholesterol (10-40 mol%) combined with saturated phospholipids. Dynamic light scattering results revealed that higher cholesterol concentrations led to reduced liposome size, CF release (%), and entrapment efficiency (%). Liposome sensitivity towards S. aureus was evaluated by using CF-loaded liposomes with and without aptamer insertion. Liposomes with a higher cholesterol content (40 mol%) exhibited a strong ability to detect low bacterial concentrations down to 5 × 102 CFU/mL without relying solely on specific receptor-ligand recognition. However, functionalizing the liposome with an aptamer further improved the specificity and sensitivity of S. aureus detection at even lower concentrations, down to 80 CFU/mL, in the wide range of 80-107 CFU/mL. This study highlights the potential for optimizing the lipid composition of liposomes to improve their sensitivity for pathogen detection, particularly when combined with aptamer-based strategies.

A multi-scale approach to arabinoxylan-based emulsions: From molecular features, interfacial properties to emulsion behaviors.

Arabinoxylan (AX) is well-known for its emulsification and beneficial biological activity, but the roles of AX's molecular features and interfacial properties in AX-based emulsion behaviors were unknown. We first used a multi-scale approach to correlate molecular, interfacial, droplet characteristics, and bulk emulsion of AXs from corn and wheat bran (CAXs and WAXs). Our results showed that among CAXs and WAXs solution (1 %, 2 % and 3 %, w/v), 0.25 M NaOH-treated CAX and WAX showed smaller particle sizes (493 nm and 8621 nm), lower interfacial tension and stronger interfacial layer, whose emulsion exhibited smaller initial droplets (541 nm and 660 nm) and better stability. Moreover, WAXs had bigger particle sizes, lower interfacial tension and stronger interfacial layer than CAXs, but CAXs exhibited better emulsifying and emulsion-stabilizing properties than WAXs. There is a satisfactory correlation among CAXs' or WAXs' molecular features, interfacial properties and emulsion behaviors. However, a good correlation from different grains AXs cannot be established.

Antifungal activity of star anise extract against Penicillium roqueforti and Aspergillus niger for bread shelf life.

Because star anise is underutilized in the baking sector and the antifungal targets are unclear, this study aimed to investigate the antifungal effect and mechanism of star anise extract (SAE) on spoilage fungi in bread. SAE was prepared by ethanol extraction and 31 substances were identified by GC-MS, among which trans-anethole (62.62%), estragole (7.82%) and linalool (4.66%) were the major components. The antifungal activity of SAE and the three main components against Penicillium roqueforti and Aspergillus niger were determined by using the Oxford cup method and the sesqui-dilution method. The inhibition zones were 9.88 mm and 15.09 mm, while the minimum inhibitory concentrations were 125.00 µL/mL and 31.25 µL/mL. Trans-anethole and estragole both showed antifungal activity against Penicillium roqueforti and Aspergillus niger, while linalool only showed antifungal activity against Aspergillus niger. Propidium iodide and fluorescein diacetate staining analysis, leakage of cellular components (nucleic acids and proteins) and rise in ergosterol content indicated that SAE disrupted the integrity and permeability of the cell membrane. Malondialdehyde was increased after SAE treatment, indicating that SAE caused lipid peroxidation in the cell membrane, further confirming that it disrupted the cell membrane. At the same time, SAE interacted with membrane proteins and altered their conformation, resulting in cell membrane dysfunction. Finally, the shelf life test showed that SAE extended the shelf life of the bread by up to 6 days. In general, this study highlights the antifungal effect of SAE against Penicillium roqueforti and Aspergillus niger, which indicated that SAE can be used as an antifungal agent to extend the shelf life of bread.

Impact of red kidney bean protein on starch digestion and exploring its underlying mechanism.

This study aimed to investigate the effect of different proportions of red kidney bean protein (RKP) on the digestibility of co-gelatinized wheat starch (WS) and corn starch (CS), as well as explore the potential underlying mechanisms. The results showed a significant reduction in both the rate and extent of digestion for WS and CS after adding the RKP during co-gelatinization. Furthermore, incorporating RKP at 0 % to 20 % levels increased the content of resistant starch (RS) by 34.89 % and 14.43 % in the digested systems of wheat starch and maize starch, respectively, while decreasing the concentration of rapidly digestible starch (RDS) by 12.24 % and 20.39 %, respectively. Furthermore, RKP was found to inhibit α-amylase in a dose-dependent and non-competitive manner. Its interaction with starch occurred through hydrogen bonds and hydrophobic interactions, resulting in a modification of the short-range ordered structure of starch and ultimately leading to inhibition of starch digestion. The physical barrier effect of RKP on starch digestion also contributed to its inhibitory action. Considering the health-related delay in the rate and extent of postprandial starch digestion, Our findings have important inspirational value for the use of red kidney bean protein in hypoglycemic foods.