The effect of quinoa germ on the quality properties of fresh whey-less cheese made by ginger (Zingiber officinale) extract as a coagulant

The effect of ginger extract (GE), as a milk coagulant, was investigated on the physicochemical, proteolysis, textural profiles and sensory properties of whey-less cheese containing quinoa germ powder (QGP; 0, 3, 6 and 9%) during storage. The results showed that with increasing QGP, the dry matter, fat, soluble nitrogen at pH 4.6 and free tryptophan and tryptophan amino acids increased and protein content decreased. Consequently, it is suggested that using 6% quinoa germ in the production of whey-less cheese made by GE as a coagulant can give the most desired product with no adverse effects on the quality and sensory properties.     

Effect of processing conditions on physicochemical properties of sodium caseinate-stabilized astaxanthin nanodispersions

The aim of the present study was to investigate the preparation of sodium caseinate-stabilized astaxanthin nanodispersions as potential active ingredients for food formulations in order to optimize processing conditions. Nanodispersions containing astaxanthin were prepared by an emulsification-evaporation processing technique. The influence of the processing conditions, namely, the pressure of the high-pressure homogenizer (20-90 MPa), the number of passes through the homogenizer (0-4) and the evaporation temperature (16-66 °C) on the physicochemical properties of the prepared astaxanthin nanodispersions were evaluated using a three-factor central composite design. Average particle size, polydispersity index (PDI) and astaxanthin loss in the prepared nanodispersions were considered as response variables. The multiple-response optimization predicted that using three passes through the high-pressure homogenizer at 30 MPa for the preparation of the astaxanthin nanoemulsion and then removing the organic phase (solvent) from the system by evaporation at 25 °C provided astaxanthin nanodispersions with optimum physicochemical properties.     

A biotechnological perspective on the application of iron oxide nanoparticles

In recent decades,magnetic iron nanoparticles (NPs) have attracted much attention due to properties such as superparamagnetism,high surface area,large surface-to-volume ratio,and easy separation under external magnetic fields.Therefore,magnetic iron oxides have potential for use in numerous applications,including magnetic resonance imaging contrast enhancement,tissue repair,immunoassay,detoxification of biological fluids,drug delivery,hyperthermia,and cell separation.This review provides an updated and integrated focus on the fabrication and characterization of suitable magnetic iron NPs for biotechnological applications.The possible perspective and some challenges in the further development of these NPs are also discussed.     

Controlled release from polyurethane films: Drug release mechanisms

In this study, polyurethane-films loaded with diclofenac were used to analyze the drug release kinetics and mechanisms. For this purpose, the experimental procedures were developed under static and dynamic conditions with different initial drug loads of 10, 20, and 30%. In the dynamic condition, to better simulate the biological flow, drug release measurements were investigated at flow rates of 7.5 and 23.5 ml/s. These values indicate the flow rate of the internal carotid artery (ICA) for a normal state of a body and for a person during the exercise, respectively. The experimental data were analyzed and adjusted by Higuchi, Korsmeyer–Peppas, First-order, zero-order, and Peppas–Sahlin models in order to understand the mechanisms contributed. Finally, drug release mechanisms were specified by investigating the model correlation coefficients. Experimental results showed that increasing the flow rate and initial drug loads enhance drug liberation. In addition, the rate of release is more influenced by the drug dosage in the static state. The analysis revealed that diffusion, burst, and osmotic pressure are the principal mechanisms contributed. Moreover, Fickian type was the dominant mechanism at all duration of release. However, it was discovered using Peppas–Sahlin model that the contribution of the diffusion mechanism decreases with increasing flow rate and initial dosage. Furthermore, the tests at different drug dosages showed that the number of stages in medication release profile is independent of the flow rate and the medicine percentage. One can conclude that the drug release kinetic in static state is more influenced by drug dosage compared with dynamic state.     

Effects of pH,Ions, and Thermal Treatments on Physical Stability of Astaxanthin Nanodispersions

In this work, astaxanthin nanodispersions were prepared using selected three component stabilizer system through a solvent-diffusion technique, with the particle size of 98.3 nm. The stability of produced nanodispersions against pH, salts, and heating were then evaluated. The produced nanodispersions exhibited good physical stability under wide ranges of pH (except around isoelectric point), sodium ion concentrations, and relatively high-temperature treatments (up to 60°C). However, formation of large particles was observed in either presence of calcium ions or higher thermal treatments (more than 60°C).     

Effects of rotation speed and time,as solvent removal parameters,on the physico-chemical properties of prepared α-tocopherol nanoemulsions using solvent-displacement technique

Food Science and Biotechnology - A bottom-up approach based on solvent-displacement technique was used to prepare α-tocopherol nanoemulsions. Effects of two main evaporation parameters namely,...     

Optimization of Mixing Parameters for α-Tocopherol Nanodispersions Prepared Using Solvent Displacement Method

A bottom-up approach based on a solvent displacement technique was used for the production of α-tocopherol nanodispersions. Response surface methodology was utilized to study the effect of the mixing conditions of organic and aqueous phases, namely, mixing speed (1 × 100–6 × 100 rpm) and mixing time (30–150 s) on the average particle size (nm), polydispersity index and α-tocopherol concentration (mg/L) of the nanodispersions. Second order regression models, with high coefficient of determination values (R ² > 0.94 and adjusted R ² > 0.79), were significantly (p < 0.05) fitted for predicting the α-tocopherol nanodispersion characteristics as functions of mixing parameters. A multiple optimization procedure presented the optimum mixing speed and time as 3.8 × 100 rpm and 70 s, respectively. The statistically insignificant differences between experimental and predicted values of studied responses, verified the satisfactoriness of the models found for explaining the variation of produced nanodispersions, as a function of mixing conditions.     

Colloidal astaxanthin: Preparation, characterisation and bioavailability evaluation

Astaxanthin colloidal particles were produced using solvent-diffusion technique in the presence of different food grade surface active compounds, namely, Polysorbate 20 (PS20), sodium caseinate (SC), gum Arabic (GA) and the optimum combination of them (OPT). Particle size and surface charge characteristics, rheological behaviour, chemical stability, colour, in vitro cellular uptake, in vitro antioxidant activity and residual solvent concentration of prepared colloidal particles were evaluated. The results indicated that in most cases the mixture of surface active compounds lead to production of colloidal particles with more desirable physicochemical and biological properties, as compared to using them individually. The optimum combination of PS20, SC and GA could produce the astaxanthin colloidal particles with small particle size, polydispersity index (PDI), conductivity and higher zeta potential, mobility, cellular uptake, colour intensity and in vitro antioxidant activity. In addition, all prepared astaxanthin colloidal particles had significantly (p<0.05) higher cellular uptake than pure astaxanthin powder.     

Developing a three component stabilizer system for producing astaxanthin nanodispersions

Astaxanthin nanodispersions were prepared using Polysorbate 20 (PS20), sodium caseinate (SC) and gum Arabic (GA), solely or in combinations, as stabilizer system, through a solvent-diffusion process. The interactions among these three surface active compounds, in the formation, physicochemical and stability characterization of produced nanodispersions were studied by applying a simplex centroid mixture design. Quadratic or special cubic regression models were fitted for variations of all studied responses as function of significant (p < 0.05) interaction effects between stabilizer components’ proportions, with acceptable determination coefficients (>0.70). Multiple-response optimization predicted that by using 29% (w/w) PS20, 6% (w/w) GA and 65% (w/w) SC as a three component stabilizer system, an astaxanthin nanodispersion could be produced with the most desirable physicochemical characteristics and highest physicochemical stability. At this optimum stabilizer components proportions, the corresponding predicted response values for mean particle size, polydispersity index (PDI) and total astaxanthin loss were predicted to be 114.6 nm, 0.261 and 680 mg/L, respectively. The optimum astaxanthin nanodispersions also showed 2.06% and 1.05% particle size growth at 25 °C and 5 °C, 4.56% and 1.29% PDI growth at 25 °C and 5 °C, and 20% (w/w) astaxanthin loss at 25 °C after 8 weeks of storage. The absence of significant (p > 0.05) differences between the experimental and predicted values of the response variables confirmed the adequacy of the fitted models.