Yoghurt Production Potential of Lactic Acid Bacteria Isolated from Leguminous Seeds and Effects of Encapsulated Lactic Acid Bacteria on Bacterial Viability and Physicochemical and Sensory Properties of Yoghurt

This study aims to determine the yoghurt production potential of lactic acid bacteria isolated from legumes seeds (lentils, beans, cowpea, and broad beans) and examine the effects of alginate capsules of selected starter cultures with high yoghurt production potential on the physicochemical properties, sensory properties of yoghurt, and bacterial viability during storage time at 4°C. The exopolysaccharide (EPS), proteolytic activity, and acidification properties of eight different isolates were determined, and sixteen different yoghurt combinations prepared. The samples showed similar physicochemical (pH, titratable acidity, dry matter, and whey separation), bacterial count, and sensory results in comparison with the commercial yoghurt used as a control sample. The acidity and pH of the yoghurt samples were significantly affected by the storage time. Total solids of yoghurt samples generally tend to decrease and syneresis of yoghurt samples also differed for each starter culture combination during the storage time. The total count of lactic acid bacteria during the storage time was higher than 107 CFU/g. The sensory analysis results of bacterial combinations are significantly different ( p < 0.05 ). Results indicated that isolated starter cultures have potential as commercial starters to improve the quality of yoghurt. Selected starter cultures with yoghurt production potential were encapsulated. Lactic acid bacteria with encapsulation efficiency of 86,3 ± 0,2 and 82,26 ± 0,79 were selected for yoghurt production. The physicochemical properties of the yoghurt with free and encapsulated starter culture were significantly different during the storage time. The reduction (∼0,5 log cfu/g) in the numbers of free and encapsulated starter cultures is over during the storage time ( p < 0.05 ). The acceptability of yoghurt containing encapsulated bacteria was lower than the yoghurt containing free bacteria by the panelists. Consequently, it was determined that alginate capsules increased bacterial viability, but the sensory properties of yoghurt were affected adversely. The LAB isolated form legumes can be introduced to the national microbial collection.

Comparison of the Therapeutic Effects of hUC-MSC Intravenous Delivery and Intraperitoneal Administration of MSCs Encapsulated in Alginate Capsules for the Treatment of Rat Liver Cirrhosis

Mesenchymal stem cells are the most promising regenerative medicine tool for treating various diseases, including liver disease, although the exact mechanism of their therapeutic action remains unclear. It was found that MSCs are captured by the lungs after systemic transplantation, quickly disappear, and are not detected at the site of injury but at the same time exhibit an obvious therapeutic effect. Comparison of the MSC efficiency depending on the route of their administration may shed light on the mechanisms involved in implementing MSC therapeutic potential. In this work, we compared the therapeutic effects of human umbilical cord MSCs (hUC-MSCs) administered systemically and intraperitoneally in the form of MSCs encapsulated in alginate capsules in a CCl4-induced model of liver cirrhosis in rats. Our study showed that both treatments resulted in liver recovery. MSC transplantation by two different routes led to a decrease in collagen deposition, the disappearance of the fibrous area by the 13th week, and the normalization of the morphometric parameters of liver parenchyma cells. In addition, the expression of some genes (EGF, alpha SMA, GFAP) which is activated in liver injury, decreased to the level observed in negative control animals. However, a detailed study of liver recovery in dynamics showed that encapsulated MSCs led to faster normalization in several parameters of the liver tissue. Our results showed that human umbilical cord MSCs effectively exhibit their therapeutic properties when using both transplantation methods. However, intraperitoneal administration of encapsulated MSCs accelerated the process of liver regeneration.

Thermal and Mechanical Properties of Calcium Alginate Capsules for Self-Healing Asphalt Concrete

The key physical and mechanical property is the strength of the capsules, which ensure the implementation of the self-healing technology, in which the capsules are not destroyed during the compaction of the asphalt concrete mixture, but are destroyed during the formation of defects in the asphalt concrete. An increase in the content of the reducing agent in the composition of the alginate emulsion leads to a decrease in the breaking load during compression of the capsules, which is explained by an increase in their diameter. But the change in the content of sodium alginate does not have a significant effect on mechanical properties. As a result of exposure to a temperature of 170 °C, a decrease in the strength of the capsules by 22 % after 1 hour of exposure in the burning oven is observed, and with an increase in the time to 4 hours, the strength decreases by 46.9 %. The maximum decrease in the strength index after 4 hours of exposure at a temperature of 160 °C reaches 29.9 %. A decrease in temperature to 150 °C leads to a decrease in the loss of strength. The strength of the capsules decreases by 4 % after 4 hours of exposure at 150 °C. Exposure of capsules to a temperature of 140 °C has no significant effect on strength.

Conductive Compartmented Capsules Encapsulating a Bitumen Rejuvenator

This paper explores the potential use of conductive alginate capsules encapsulating a bitumen rejuvenator as a new extrinsic self-healing asphalt method. The capsules combine two existing self-healing asphalt technologies: (1) rejuvenator encapsulation and (2) induction heating to create a self-healing system that will provide rapid and effective asphalt pavement repair. The work presents a proof of concept for the encapsulation process, which involves embedding the capsules into the bitumen mortar mixture and the survival rate of the capsules in the asphalt mixture. A drip capsule production process was adopted and scaled up to the production of 20l wet capsules at rate of 0.22 l/min. To prove the effectiveness and its ability to survive asphalt production process, the capsules were prepared and subjected to thermogravimetric analysis (TGA) and uniaxial compression Test (UCT). The test results demonstrated that the capsules had suitable thermal characteristics and mechanical strength to survive the asphalt mixing and compaction process. Scanning electron microscopy (SEM) was employed to investigate physiological properties, such as rejuvenator (oil) and iron particle distribution, within the capsules. The electrical resistance tests proved that the capsules were capable of conducting electrical current. The capsules were also tested for their conductive properties in order to determine whether they are capable of conducting and distributing the heat once subjected to induction heating. The results showed that capsules containing higher amounts of iron (alginate/iron powder in a ratio of 20:80 by weight) can efficiently conduct and distribute heat. To prove its success as an asphalt healing system, conductive alginate capsules encapsulating a bitumen rejuvenator were embedded in a bitumen mortar mix. The samples where then subjected to local damaging and healing events, and the degree of healing was quantified. The research findings indicate that conductive alginate capsules encapsulating a bitumen rejuvenator present a promising new approach for the development of an extrinsic self-healing asphalt pavement systems.

Digital twinning of Cellular Capsule Technology: Emerging outcomes from the perspective of porous media mechanics

Spheroids encapsulated within alginate capsules are emerging as suitable in vitro tools to investigate the impact of mechanical forces on tumor growth since the internal tumor pressure can be retrieved from the deformation of the capsule. Here we focus on the particular case of Cellular Capsule Technology (CCT). We show in this contribution that a modeling approach accounting for the triphasic nature of the spheroid (extracellular matrix, tumor cells and interstitial fluid) offers a new perspective of analysis revealing that the pressure retrieved experimentally cannot be interpreted as a direct picture of the pressure sustained by the tumor cells and, as such, cannot therefore be used to quantify the critical pressure which induces stress-induced phenotype switch in tumor cells. The proposed multiphase reactive poro-mechanical model was cross-validated. Parameter sensitivity analyses on the digital twin revealed that the main parameters determining the encapsulated growth configuration are different from those driving growth in free condition, confirming that radically different phenomena are at play. Results reported in this contribution support the idea that multiphase reactive poro-mechanics is an exceptional theoretical framework to attain an in-depth understanding of CCT experiments, to confirm their hypotheses and to further improve their design.

The Effect of Extrusion Voltage and Flowrate to the Viability and Survivability of Probiotic L. casei Encapsulated in Alginate-Chitosan

Chitosan-coated L. casei containing alginate capsules (shortened as L. casei capsules) were prepared by extruding L. casei containing alginate solution at different extrusion voltage and and flow rate followed by coating the wet capsules in chitosan solution. This study aimed to determine the effect of extrusion voltage and sodium alginate liquid flow rate on the viability of L. casei bacteria in the encapsulation process. The encapsulation process in this study was carried out by the extrusion method using sodium alginate of 1% (w/v) and chitosan of 0.2% (w/v). The resulted beads were immersed in a simulated gastric fluid (SGF) (NaCl 0.2%; HCl 0.5 M with a pH of 1.5) for 1, 60, and 120 min at 37 °C. The number of L. casei cells before encapsulation was 12.3 log CFU. After encapsulation, the maximum viability of L. Casei obtained by voltage variations of 0 kV and flow rate 5 mL/min were 12.26 log CFU. After testing the beads in SGF for 1 min, the results obtained indicate that viability of L.casei in the sodium alginate - chitosan beads with an extrusion voltage of 0 kV and 5 mL/min was 11.8 log CFU/g. The result indicated that encapsulated L. casei in the sodium alginate - chitosan beads with a voltage of 0 kV and 5 mL/min was the highest survivability level of 97.38 %. The conclusions of the study were The higher extrusion voltage can kill more L. casei while the higher extrusion flow rate can protect more L. casei.