Production of biological nanoparticles from &#920- lactalbumin for drug delivery and food science application

In recent years, the concept of controlled release of encapsulated ingredients at the right place and the right time has become of more interest to the food and pharmaceutical industry. Whey proteins are valuable by-products from the cheese industry. The physicochemical properties of the whey proteins suggest that they may be suitable for novel food and drug delivery system. The objective of this study was to characterize the two step desolvation process of -lactalbumin for preparation of its nanoparticles. Following the desolvation of the protein with acetone, the produced nanoparticles were stabilized and cross linked by addition of glutaraldehyde. Nanoparticle sample was subsequently purified by 3 cycle’s centrifugation (15000 ×g, 20 min). Three process parameters were examined to achieve a suitable size of nanoparticles including the pH value, temperature and desolvating agent type. In addition, fabricated nanoparticles were analyzed by photon correlation spectroscopy (PCS) as well as scanning electron microscopy (SEM). The smallest size of the nanoparticles achieved was 102 nm while the largest size was 454 nm

Prediction of Water Activity Coefficient in TEG-Water System Using Diffusion Neural Network (DNN)

Accurate determination of activity coefficients of water in a binary triethylene glycol (TEG)-water system, is of prime concern in designing the natural gas dehydration process. In this work, a hybrid model (a combination of information diffusion theory and neural network) and a so-called diffusion neural network (DNN) have been developed for the prediction of activity coefficients of a binary TEG-water system. Owing to the insufficient experimental data available in the literature for binary mixtures, and in particular for infinite dilution, we have employed the information diffusion technique as a tool in extrapolating data points from the original data. By means of this technique, a new dataset has been trained and optimized for the DNN model with more nodes in the input and the output layers. The result of this study reveals that DNN model is superior to the conventional neural nets in predicting the activity coefficient of water in the range of temperature (293–387.6 K) and mole fractions with mean absolute error of 0.31 % (MAE = 0.31 %), and high correlation coefficient of 0.999 (r = 0.999). Furthermore, the results of this work using DNN have also been compared with Parrish’s correlation. The findings of this work demonstrate that the DNN model exhibits better results over Parrish’s correlation in predicting the activity coefficients of water in a binary triethylene glycol-water system with a mean absolute error of 5.03 percent (MAE = 5.03 %)

Effect of the loading of di- and tri-valent metal cations on the performance of sulfated silica-titania nano-catalyst in the esterification reaction

In this study, a series of sulfated silica-titania catalysts were modified by metal cations (Al, Co, Zr, Cr, and Zn) to enhance the catalytic activity and stability of sulfated silica-titania in the esterification reaction. The results indicated that the sulfate phases of sulfated silica-titania were mostly changed to TiO(SO4) by the incorporation of support cations. It affected the acidity content of the samples and the bonding strength between the sulfate group and the support surface. Moreover, the mean pore size was drastically increased which had a positive influence on the activity of the sample in the esterification reaction. The results of catalytic activity showed that all the samples had suitable activity at 120°C, whereas the sulfated silica-titania catalyst that was reinforced by Al3+ exhibited less activity reduction by setting the temperature to 90°C. The highest conversion of oleic acid (90.7 ± 2%) was obtained under optimal reaction conditions including the temperature of 90°C, methanol/oleic acid molar ratio of 9:1, 3 wt.% catalyst, and reaction time of 3 h. The sulfated silica-titania modified by Al3+ also exhibited good catalytic stability for six cycles while a high reduction in the activity of sulfated silica-titania catalyst was observed

Preparation of Nano-Size Al-Promoted Sulfated Zirconia and the Impact of Calcination Temperature on Its Catalytic Activity

Solvent-free technique was employed in this work in order to assess the influence of the calcination temperature on the activity of Al-promoted sulfated zirconia. The catalyst was analyzed by XRD and IR-spectrum method, and catalytic activity was examined by esterification reaction of oleic acid. XRD analysis revealed that a decline in the percentage of tetragonal phases of zirconia was observed by increasing the calcination temperature from 500 to 900 °C. In addition, a reduction of sulfate groups as SO42– on zirconia surface was observed. As a consequence, a decline in Brønsted sites with calcinationtemperature enhancement also prevailed. Therefore, the size of Al-promoted sulfated zirconia particles was increased accordingly. On the other hand, with the aluminum sulfate loading, the amount of sulfate ions on Al-promoted sulfated zirconia surface was enhanced and a reduction in particle size of Al2O3/S-ZrO2 was also observed, as compared to non-promoted. The result of this study revealed that an increase of sulfate and alumina groups causes a raise in the acidity of catalyst. Furthermore, the calcined Al-promoted and non-promoted sulfated zirconia would convert 96.10 % and 89.36 % of oleic acid to biodiesel, respectively. Therefore, Al2O3/S-ZrO2 as a catalyst exhibits a higher activity than S-ZrO2

Effect of Calcination Temperature on Catalytic Activity of Synthesis SrO/S-ZrO2 by Solvent-free Method in Esterification of Oleic Acid

Currently, the major concern in production of biodiesel fuel is to exploit new catalysts with the optimal conditions. In this study, the effect of calcination temperature on the synthesis of 20 mol % SrO/S-ZrO2 was examined by solvent-free method. Moreover, the ability of the catalyst for esterification reaction of oleic acid with methanol was also assessed. To obtain this objective, X-ray diffraction and infra-red spectroscopy method was employed to characterize the structure of the catalysts. The results of this study reveal that the calcined strontium oxide promoted sulfated zirconia at 500 °C has the highest percentage of tetragonal phases of zirconia. It has also been demonstrated that owing to the high percentage of the tetragonal phases of zirconia and the acidity of the catalyst, conversion of oleic acid to fatty acids methyl esters (i.e., FAME) could be enhanced from 88.36 % to 91.13 %. Moreover, it has also been shown that 20 mol % SrO/S-ZrO2 exhibits higher activity in comparison with S-ZrO2 at 500 °C in esterification reaction due to the presence more sulfate ions and higher activity of strontium ions

Preparation of Supported Nanosized Sulfated Zirconia by Strontia and Assessment of Its Activities in the Esterification of Oleic Acid

The aim of this study was to examine a new nanocatalyst of SrO/S-ZrO2 in esterification reaction and the optimum value of strontia loading over the sulfated zirconia. The sulfated zirconia was supported with different molar ratios of strontia in the range of 0.0–0.30, using the solvent-free method. The samples were characterized using XRD, FT-IR, BET and TEM analysis and their activity were investigated in esterification reaction of oleic acid. The findings of this study revealed that 25 mol % SrO/S-ZrO2 had the highest yield in the esterification reaction. It was also concluded that strontia-supported sulfated zirconia could improve the low reusability of the catalyst. Furthermore, 95 % conversion was also obtained at optimized conditions (i.e., 100 °C, 2 wt. % of catalyst, 6:1 molar ratio of methanol/oleic acid and for a period of 30 minutes)