The Effect of Drinking Yoghurt Containing Free and Microencapsulated Probiotic Bacteria on Changes of the Population of These Bacteria in the Digestive System

Background & Aims: Probiotic bacteria have beneficial effects on host's health. However, one of the most important reasons which affect the probiotic activity of a microorganism is its survival during the gut transit. Microencapsulation techniques could be applied to bacteria to improve this parameter. Methods: In this study, feces of 60 healthy volunteers were analyzed during 28-day test period to assess changes of probiotic bacteria. Participants were divided into equal 4 groups; group 1 did not receive probiotic drinking yoghurt (control); group 2 received probiotic drinking yoghurt containing free Lactobacillus acidophilus and Bifidobacterium animalis, subspecies lactis; group 3 recieved the same strains microencapsulated with sodium alginate/resistant starch; and group 4 received probiotic drinking yoghurt containing microencapsulated probiotic bacteria with sodium alginate/chitosan. Results: A significant increase was recorded in the population of lactobacilli and bifidobacteria in the feces of participant in three groups at the end of the treatment compared with control group (P < 0.05 for all), confirming the ability of the 2 strains to colonize the human gut, either in a gastroprotected form or not. Participants treated with the microencapsulated bacteria reported more viability than those received not encapsulated strains. Feces of group 3 that received drinking yoghurt containing encapsulated probiotic bacteria with alginate/resistant starch had higher amount of probiotic bacterial populations, 1.3 ± 0.26 × 107 and 2.4 ± 0.37 × 109 cfu/g Lactobacillus acidophilus and Bifidobacterium animalis subs lactis, respectively. Conclusion: Consumption of the drinking yoghurts containing probiotic bacteria increased the Lactobacillus acidophilus and Bifidobacterium animalis, subspecies lactis, contents of the feces and encapsulation process improved stability of probiotic bacteria

Prediction of necrotic core and hypoxic zone of multicellular spheroids in a microbioreactor with a U-shaped barrier

© 2018 by the authors. Microfluidic devices have been widely used for biological and cellular studies. Microbioreactors for three-dimensional (3D) multicellular spheroid culture are now considered as the next generation in in vitro diagnostic tools. The feasibility of using 3D cell aggregates to form multicellular spheroids in a microbioreactor with U-shaped barriers has been demonstrated experimentally. A barrier array is an alternative to commonly used microwell traps. The present study investigates oxygen and glucose concentration distributions as key parameters in a U-shaped array microbioreactor using finite element simulation. The effect of spheroid diameter, inlet concentration and flow rate of the medium are systematically studied. In all cases, the channel walls are considered to be permeable to oxygen. Necrotic and hypoxic or quiescent regions corresponding to both oxygen and glucose concentration distributions are identified for various conditions. The results show that the entire quiescent and necrotic regions become larger with increasing spheroid diameter and decreasing inlet and wall concentration. The shear stress (0.5-9 mPa) imposed on the spheroid surface by the fluid flow was compared with the critical values to predict possible damage to the cells. Finally, optimum range of medium inlet concentration (0.13-0.2 mM for oxygen and 3-11 mM for glucose) and flow rate (5-20 μL/min) are found to form the largest possible multicellular spheroid (500 μm), without any quiescent and necrotic regions with an acceptable shear stress. The effect of cell-trap types on the oxygen and glucose concentration inside the spheroid was also investigated. The levels of oxygen and glucose concentration for the microwell are much lower than those for the other two traps. The U-shaped barrier created with microposts allows for a continuous flow of culture medium, and so improves the glucose concentration compared to that in the integrated U-shaped barrier. Oxygen concentration for both types of U-shaped barriers is nearly the same. Due to the advantage of using U-shaped barriers to culture multicellular spheroids, the results of this paper can help to choose the experimental and design parameters of the microbioreactor

Inhibitory impacts of natural antioxidants (ascorbic and citric acid) and vacuum packaging on lipid oxidation in frozen Persian sturgeon fillets

This study was aimed to investigate effects of aqueous citric acid (CA) and ascorbic acid (AA) on lipid oxidation in comparison with effect of vacuum packaging in order to find better treatment to delay improper changes in the Persian sturgeon (Acipenser persicus) fillets during frozen storage due to lipid oxidation. In this study traditional packaging, vacuum packaging, ascorbic acid solution (0.5 %) and citric acid solution (0.5 %) were considered as treatments. Rancidity development was measured by several biochemical indicators including Free Fatty Acids, Peroxide values and Thiobarbituric acid. Also pH, expressible moisture and sensory properties were measured during 6 months storage. Results showed that free fatty acid (FFA), primary and secondary oxidation products of control samples were significantly higher than those in other treatments (p<0.05). Also, expressible moisture and pH value of treated samples were significantly lower than those in control (p<0.05). However both antioxidants (AA and CA) extended shelf life of frozen fillets but rancidity development in CA treated samples was higher than other samples during storage. Results showed that all three treatments had significant effect on delaying lipid oxidation (p<0.05) but usage of AA and vacuum packaging had the best effect on delaying lipid oxidation and increasing shelf-life of fillets (p<0.05) . Thus the employment of AA and vacuum packaging alone or in combination with other protective strategies is recommended

Evaluation of the Importance of Multi-objective Particle Swarm Algorithm Parameters in Optimizing the Solutes Rejection of Camel Milk Ultrafiltration Using Partial Least Squares Regression

Introduction  Ultrafiltration is one of the most common membrane processes in the dairy industry, especially for condensing and separating milk components. Using this process, several products can be produced, including milk concentrate used for cheese production, low-lactose dairy products, milk protein concentrate, and serum proteins for dietary supplements. The efficiency and cost of a membrane process depend on the percentage of rejection of the soluble components. Therefore, the use of concentrated milk made by ultrafiltration in the production of various dairy products depends on the efficiency of the membrane process and the changes in milk components during this process. On the one hand, the physicochemical properties of camel milk are different from those of cow milk, especially in terms of type and amount of protein. Because significant differences exist between the physicochemical properties of camel and cow milk, likely, the membrane processing conditions and the physicochemical properties of their products will be different completely. Although many studies have been conducted on the efficacy of the ultrafiltration processing of cow milk, there is no information about the efficacy of camel milk ultrafiltration, and most of the research done regarding optimizing is based on classical algorithms, Therefore, in this study, the effects of transmembrane pressure and temperature on the solutes rejection (protein, lactose, ash, and total solids) during camel milk ultrafiltration process were investigated, Then, these properties were optimized using particle swarm algorithm. Also, because the performance of the particle swarm algorithm is highly dependent on related parameters such as the number of iterations, the number of particles, accelerate constant, inertia weight, and velocity of the particles, so before optimization, the effect of these parameters on optimal responses were examined by partial least squares regression (PLS).   Materials and Methods  In this study, a pilot crossflow ultrafiltration system was used. A UF membrane (Model 3838 HFK-131, Koch membrane systems, Inc., USA) made of polysulfone amid (PSA) with MWCO of 20 kDa was applied. Camel milk was purchased from a local market in Mashhad and for camel skim milk production, its fat was separated by a pilot plant milk fat separator in the Food Research Complex, Ferdowsi University of Mashhad. The weight percentages of protein, fat, lactose, ash, and total solids of UF permeate samples were measured by ISO 8968-1:2014, ISO 1211: 2010, ISO 26462/IDF 214:2010, ISO 5544:2008, and ISO 6731:2010 at two replications, respectively. the process treatments were performed in the form of a central composite design (CCD) (5 replications at the central point) for two independent variables at three levels so that the total number of 13 treatments was obtained. The data were modeled using the statistical software of Design Expert (version 11) based on the response surface methodology and each of the response variables in the form of a regression model was presented as a function of independent variables.   Results and Discussion  The rejection of total solids and protein of the tested samples varied in the range of 45.4-51.03% and 94.09-97.51%, respectively. It means that in each TMP and T, more than 45% of the total solids and 94% of the protein of camel milk were kept by the membrane. The results also showed that none of the linear, quadratic and interactive effects of TMP and T on the total solids and protein rejections were not significant. According to the results, the RL reduced with increasing T. Increasing the TMP also led to a reduction at high T and an increase in RL rate of the samples at lover T. Also, the effect of TMP on RA showed a non-linear trend, so that TMP at high T led to an increase, and at low T, it led to a reduction in the RA of the samples.   Conclusion  The optimization results with the particle swarm algorithm showed that this algorithm has a high convergence speed and by recognizing and analyzing its parameters, the optimal conditions can be easily found. The optimum ultrafiltration conditions in this study with the lowest RL and RA were determined as 80 kPa TMP and 29.85 ͦ C T

Novel approaches in cancer management with circulating tumor cell clusters

© 2019 The Authors Tumor metastasis is responsible for the vast majority of cancer-associated morbidities and mortalities. Recent studies have disclosed the higher metastatic potential of circulating tumor cell (CTC) clusters than single CTCs. Despite long-term study on metastasis, the characterizations of its most potent cellular drivers, i.e., CTC clusters have only recently been investigated. The analysis of CTC clusters offers new intuitions into the mechanism of tumor metastasis and can lead to the development of cancer diagnosis and prognosis, drug screening, detection of gene mutations, and anti-metastatic therapeutics. In recent years, considerable attention has been dedicated to the development of efficient methods to separate CTC clusters from the patients’ blood, mainly through micro technologies based on biological and physical principles. In this review, we summarize recent developments in CTC clusters with a particular emphasis on passive separation methods that specifically have been developed for CTC clusters or have the potential for CTC cluster separation. Methods such as liquid biopsy are of paramount importance for commercialized healthcare settings. Furthermore, the role of CTC clusters in metastasis, their physical and biological characteristics, clinical applications and current challenges of this biomarker are thoroughly discussed. The current review can shed light on the development of more efficient CTC cluster separation method that will enhance the pivotal understanding of the metastatic process and may be practical in contriving new strategies to control and suppress cancer and metastasis

Inhibitory impacts of natural antioxidants (ascorbic and citric acid) and vacuum packaging on lipid oxidation in frozen Persian sturgeon fillets

Abstract This study was aimed to investigate effects of aqueous citric acid (CA) and ascorbic acid (AA) on lipid oxidation in comparison with effect of vacuum packaging in order to find better treatment to delay improper changes in the Persian sturgeon (Acipenser persicus) fillets during frozen storage due to lipid oxidation. In this study traditional packaging, vacuum packaging, ascorbic acid solution (0.5 %) and citric acid solution (0.5 %) were considered as treatments. Rancidity development was measured by several biochemical indicators including Free Fatty Acids, Peroxide values and Thiobarbituric acid. Also pH, expressible moisture and sensory properties were measured during 6 months storage. Results showed that free fatty acid (FFA), primary and secondary oxidation products of control samples were significantly higher than those in other treatments (p&lt;0.05). Also, expressible moisture and pH value of treated samples were significantly lower than those in control (p&lt;0.05). However both antioxidants (AA and CA) extended shelf life of frozen fillets but rancidity development in CA treated samples was higher than other samples during storage. Results showed that all three treatments had significant effect on delaying lipid oxidation (p&lt;0.05) but usage of AA and vacuum packaging had the best effect on delaying lipid oxidation and increasing shelf-life of fillets (p&lt;0.05). Thus the employment of AA and vacuum packaging alone or in combination with other protective strategies is recommended

Maximizing the freeze-dried extract yield by considering the solvent retention index: extraction kinetics and characterization of Moringa oleifera leaves extracts

A complete chemical characterization of Moringa oleifera leaves was carried out showing a high content of extractives. Extraction kinetics of bioactive compounds present in this fraction were performed by conventional and ultrasound assisted extraction (UAE). A 50% (v/v) hydroalcoholic mixture led to the highest total phenolic compounds yield by conventional solvent extraction, 29.5 ± 0.3 mg per gram of moringa leaves. UAE did not bring any improvement when using hydroalcoholic mixtures probably due to the physical properties of the ethanol aqueous mixtures that affect the UAE performance, such as viscosity and vapor pressure of the mixture. The retention index of the different solvents in the raffinate phase was determined revealing the highest retention index for water, 9.5, and a continuous decrease by increasing ethanol concentration. Retention index is a key parameter in a solvent extraction process since it determines the number of stages in an industrial separation process and it is not usually reported in bioactive compounds extraction. Solvent extraction capacity and the retention index determined the final freeze-dried extract yield.Junta de Castilla y León (JCyL) and the European Regional Development Fund (ERDF) [grantnumbers BU301P18 and BU050P20]; and the Agencia Estatalde Investigación [grant number AEI/10.13039/501100011033]

Spheroids-on-a-chip: Recent advances and design considerations in microfluidic platforms for spheroid formation and culture

© 2018 Elsevier B.V. A cell spheroid is a three-dimensional (3D) aggregation of cells. Synthetic, in-vitro spheroids provide similar metabolism, proliferation, and species concentration gradients to those found in-vivo. For instance, cancer cell spheroids have been demonstrated to mimic in-vivo tumor microenvironments, and are thus suitable for in-vitro drug screening. The first part of this paper discusses the latest microfluidic designs for spheroid formation and culture, comparing their strategies and efficacy. The most recent microfluidic techniques for spheroid formation utilize emulsion, microwells, U-shaped microstructures, or digital microfluidics. The engineering aspects underpinning spheroid formation in these microfluidic devices are therefore considered. In the second part of this paper, design considerations for microfluidic spheroid formation chips and microfluidic spheroid culture chips (μSFCs and μSCCs) are evaluated with regard to key parameters affecting spheroid formation, including shear stress, spheroid diameter, culture medium delivery and flow rate. This review is intended to benefit the microfluidics community by contributing to improved design and engineering of microfluidic chips capable of forming and/or culturing three-dimensional cell spheroids