Vegetable proteins in microencapsulation: a review of recent interventions and their effectiveness

Proteins from vegetable seeds are interesting for research at present because they are an abundant alternative to animal-based sources of proteins and petroleum-derived polymers. They are a renewable and biodegradable raw material with interesting functional and/or physico-chemical properties. In microencapsulation, these biopolymers are used as a wall forming material for a variety of active compounds. In most cases, two techniques of microencapsulation, spray-drying and coacervation, are used for the preparation of microparticles from vegetable proteins. Proteins extracted from soy bean, pea and wheat have already been studied as carrier materials for microparticles. These proteins could be suitable shell or matrix materials and show good process efficiency. Some other plant proteins, such as rice, oat or sunflower, with interesting functional properties could be investigated as potential matrices for microencapsulation

Synthesis and properties of lipoamino acid/fatty acid mixtures. Influence of the amphiphilic structure.

The acylation of amino acids by acid chlorides with from 8 to 12 carbon atoms, in alkaline aqueous medium following Shotten-Baumann reaction, results in sodium salts of Nα-acylamino acids and fatty acids mixture. These lastest are present in proportion from 40 to 60%. These compositions represent mixtures of amphiphilic anionic surfactants. They contribute together to the properties of the formulation. Measurements of the surface-active properties of these formulations, such as critical micelle concentration (CMC), surface tension at the CMC (TS), foaming capacity (FC) and foaming stability (FS), show that surfactant mixtures with the longest chain have the most desirable properties. They are comparable to commercial petroleum-based surfactants. Thus, the CMC, TS and CM values of the formulation obtained starting from leucine and dodecanoyl chloride (310 mg/L, 30.1 mN/m and 200%, respectively) are similar, even better than, sodium dodecylsulfate (290 mg/L, 39.1 mN/m and 230%, respectively

Influence of soy protein’s structural modifications on their microencapsulation properties: a-tocopherol microparticles preparation

Enzymatic and chemical modifications of soy protein isolate (SPI) were studied in order to improve SPI properties for their use as wall material for a-tocopherol microencapsulation by spray-drying. The structural modifications of SPI by enzymatic hydrolysis and/or N-acylation were carried out in aqueous media without any use of organic solvent neither surfactant. Emulsions from aqueous solutions of native or modified SPI and hydrophobic a-tocopherol, were prepared and spray-dried to produce a-tocopherol microparticles. The effect of protein modifications and the influence of the core/shell ratio on both emulsions and microparticles properties were characterised. The obtained results demonstrated that oil-in-water emulsions prepared with modified proteins had lower droplet size (0.5-0.9 μm) and viscosity (3.6-14.8 mPa×s) compared to those prepared with native proteins (1.1 μm and 15.0 mPa×s respectively). Efficiency of oil retention decreased after protein hydrolysis from 79.7 to 38.9%, but the grafting of hydrophobic chain by acylation improved efficiency of a-tocopherol retention up to 94.8%. Moreover, higher emulsion viscosity, particle size and process efficiency were observed with the increase of a-tocopherol amount

Multi-metal contamination of a calcic cambisol by fallout from a lead-recycling plant

The present study deals with the impact of a lead-recycling plant on metal accumulation in soils, evaluated by a global pedological analysis. This general approach can be used on various contaminated sites to evaluate impact of an anthropogenic activity and inform on metal origin and behavior. A soil profile collected in the vicinity of a lead-recycling plant in operation for 40 years was studied. Correlations between major and trace elements highlighted different patterns of metals according to their origins. Two groups of metals were identified: (i) Pb, Sb, Sn, As, Cu and Zn of anthropogenic origin and (ii) Ni and Cr of natural origin. The results showed that Pb, Sb and Sn presented the highest relative contamination followed by Cu, As and Zn. Moreover, Pb and Sb migrated most along the profile at an estimated rate of 1.5 cm y−1, followed by Sn, then Zn, Cu and finally As. Sequential extractions showed that all metals were mainly solubilized by reduction and therefore estimated to be bound to iron oxides, except lead which was rather in the acid-soluble fraction in the contaminated horizons. Furthermore, high levels of lead were found in water-soluble and exchangeable fractions (4.2 mg kg−1) suggesting the occurrence of lead transfer towards the trophic chain

A new way of valorizing biomaterials: the use of sunflower protein for 1 a-tocopherol microencapsulation

Biopolymer based microparticles were efficiently prepared from sunflower protein (SP) wall material and a-tocopherol (T) active core using a spray-drying technique. Protein enzymatic hydrolysis and/or N-acylation were carried out to make some structural modifications to the vegetable protein. Native and hydrolyzed SP were characterized by Asymmetrical Flow Field-Flow Fractionation (AsFlFFF). Results of AsFlFFF confirmed that size of proteinic macromolecules was influenced by degree of hydrolysis. The effect of protein modifications and the influence of wall/core ratio on both emulsions and microparticle properties were evaluated. Concerning emulsion properties, enzymatic hydrolysis involved a decrease in viscosity, whereas acylation did not significantly affect emulsion droplet size and viscosity. Microparticles obtained with hydrolyzed SP wall material showed lower retention efficiency (RE) than native SP microparticles (62-80% and 93% respectively). Conversely, acylation of both hydrolyzed SP and native SP allowed a higher RE to be reached (up to 100%). Increasing T concentration increased emulsion viscosity, emulsion droplet size, microparticle size, and enhanced RE. These results demonstrated the feasibility of high loaded (up to 79.2% T) microparticles

Green Production of Anionic Surfactant Obtained from Pea Protein

A pea protein isolate was hydrolyzed by a double enzyme treatment method in order to obtain short peptide sequences used as raw materials to produce lipopeptides-based surfactants. Pea protein hydrolysates were prepared using the combination of Alcalase and Flavourzyme. The influence of the process variables was studied to optimize the proteolytic degradation to high degrees of hydrolysis. The average peptide chain lengths were obtained at 3–5 amino acid units after a hydrolysis of 30 min with the mixture of enzymes. Then, N-acylation in water, in presence of acid chloride (C12 and C16), carried out with a conversion rate of amine functions of 90%, allowed to obtain anionic surfactant mixtures (lipopeptides and sodium fatty acids). These two steps were performed in water, in continuous and did not generate any waste. This process was therefore in line with green chemistry principles. The surface activities (CMC, foaming and emulsifying properties) of these mixtures were also studied. These formulations obtained from natural renewable resources and the reactions done under environmental respect, could replace petrochemical based surfactants for some applications

Gut microbiota-derived propionate reduces cancer cell proliferation in the liver

Peer reviewedPublisher PD