Synthesis and characterization of a lactose-based biosurfactant by a novel nanodendritic catalyst and evaluating its efficacy as an emulsifier in a food emulsion system

Antibacterial activity of bioemulsifiers/biosurfactants produced by Levilactobacillus brevisS4 and Lactiplantibacillus plantarumS5 and their utilization to enhance the stability of cold emulsions of milk chocolate drinks

Chocolate milk drink, one of the most popular and widely consumed milk products among the population, independent of their age, has as its main challenge the problem of its physical instability. The aim of this study was to assess the stabilizing effect of bioemulsifiers/biosurfactants (BE/BS) from two lactobacilli strains in a cold chocolate milk drink. The strains Levilactobacillus brevis S4 and Lactiplantibacillus plantarum S5 isolated from pendidam were screened for their ability to produce BE/BS. The produced BE/BS were characterized, their antimicrobial activities were assessed, and their ability to stabilize cold chocolate milk drinks was determined. The results obtained showed BE/BS yields of 3.48 and 4.37 g/L from L. brevis S4 and L. plantarum S5, respectively. These BE/BS showed emulsifying and surface activities that remained stable after treatment at different temperatures, pH, and salinity. The emulsions formed using BE/BS were stable for 72 h at room temperature (25 ± 1°C). The BE/BS exhibited antimicrobial activity against Staphylococcus aureus S1 and Escherichia coli E1. When applied to cold chocolate milk drinks at 0.2% (w/v), the BE/BS from L. brevis S4 and L. plantarum S5 showed interesting solubility indexes and water absorption capacities, which led to the successful stabilization of the drinks. The results of this study demonstrate the stabilizer potential of BE/BS from L. brevis S4 and L. plantarum S5 and suggest their use in the dairy and food industries.

Sugar-Based Monoester Surfactants: Synthetic Methodologies, Properties, and Biological Activities

Glycolipids are biocompatible and biodegradable amphiphilic compounds characterized by a great scientific interest for their potential applications in various technological areas, including pharmaceuticals, cosmetics, agriculture, and food production. This report summarizes the available synthetic methodologies, physicochemical properties, and biological activity of sugar fatty acid ester surfactants, with a particular focus on 6-O-glucose, 6-O-mannose, 6-O-sucrose, and 6'-O-lactose ones. In detail, the synthetic approaches to this class of compounds, such as enzymatic lipase-catalyzed and traditional chemical (e.g., acyl chloride, Steglich, Mitsunobu) esterifications, are reported. Moreover, aspects related to the surface activity of these amphiphiles, such as their ability to decrease surface tension, critical micelle concentration, and emulsifying and foaming ability, are described. Biological applications with a focus on the permeability-enhancing effect across the skin or mucosa, antimicrobial and antifungal activities, as well as antibiofilm properties, are also presented. The information reported here on sugar-based ester surfactants is helpful to broaden the interest and the possible innovative applications of this class of amphiphiles in different technological fields in the future.

Fabrication of a magnetic Mn(ii) cross-linked chitosan-amine/glutaraldehyde nanocomposite for the rapid degradation of dyes and aerobic selective oxidation of ethylbenzene†

Owing to the great demand for using sustainable, renewable, and widely available materials in catalytic systems for the conversion of waste/toxic material to high value-added and harmless products, biopolymers derived from natural sources have demonstrated great promise as an alternative to state-of-the-art materials that suffer from high costs and limitations. These have encouraged us to design and fabricate a new super magnetization of Mn–Fe₃O₄–SiO₂/amine-glutaraldehyde/chitosan bio-composite (MIOSC-N-et-NH₂@CS-Mn) for advanced/aerobic oxidation process. The morphological and chemical characterization of the as-prepared magnetic bio-composite was assessed using ICP-OES, DR UV-vis, BET, FT-IR, XRD, FE-SEM, HR-TEM, EDS, and XPS techniques. The PMS + MIOSC-N-et-NH₂@CS-Mn system was capable of degrading methylene orange (98.9% of removal efficiency) and selectively oxidizing ethylbenzene to acetophenone (conversion 93.70%, selectivity 95.10% and TOF 214.1 (10³ h⁻¹) within 8.0 min and 5.0 h, respectively. Moreover, MO was efficiently mineralized (TOC removal of ∼56.61) by MIOSC-N-et-NH₂@CS-Mn with 60.4%, 5.20, 0.03 and 86.02% of the synergistic index, reaction stoichiometric efficiency, specific oxidant efficiency, and oxidant utilization ratio in wide pH ranges, respectively. An understanding of its vital parameters and relationship of catalytic activity with structural, environmental factors, leaching/heterogenicity test, long-term stability, inhibitory effect of anions in water matrix, economic study and response surface method (RSM) were evaluated in detail. Overall, the prepared catalyst could be employed as an environmentally friendly and low-cost candidate for the enhanced activation of PMS/O₂ as an oxidant. Additionally, MIOSC-N-et-NH₂@CS-Mn exhibited great stability, high recovery efficiency, and low metal leaching, which eliminated the harsh condition reaction and supplied practical application performance for water purification and selective aerobic oxidation of organic compounds.

Optimization of the catalytic degradation of dyes and aerobic oxidation of ethylbenzene by Mn@Cross-linked Magnetic Chitosan-Amin-Glutaraldehyde.