Influence of emulsification on the properties of styrene-butadiene-styrene chemically modified bitumens

The effect of emulsification on the styrene-butadiene-styrene (SBS) chemically modified bitumens (CMBs) is studied by conventional tests, differential scanning calorimetry (DSC) and fourier transform infrared (FTIR) spectroscopy. Compared to CMBs, modified bitumen emulsion residues (MBERs) exhibit higher temperature susceptibility, inferior resistant to cracking and deformation, lower elastic recovery and storage stability whereas these properties are improved substantially relative to base bitumens. DSC results show that the thermostability of CMBs decreased slightly after emulsification which indicate the emulsification exerts very little effect on the thermal property of CMBs. The FTIR results do not indicate any chemical reaction exists on CMBs during the emulsification.

Microchannel emulsification study on formulation and stability characterization of monodisperse oil-in-water emulsions encapsulating quercetin

The study used microchannel emulsification (MCE) to encapsulate quercetin in food grade oil-in-water (O/W) emulsions. A silicon microchannel plate (Model WMS 1-2) comprised of 10,300 discrete 10 × 104 μm microslots was connected to a circular microhole with an inner diameter of 10 μm. 1% (w/w) Tween 20 was used as optimized emulsifier in Milli-Q water, while 0.4 mg ml-1 quercetin in different oils served as a dispersed phase. The MCE was carried by injecting the dispersed phase at 2 ml h-1. Successful emulsification was conducted below the critical dispersed phase flux, with a Sauter mean diameter of 29 μm and relative span factor below 0.25. The O/W emulsions remained stable in terms of droplet coalescence at 4 and 25 °C for 30 days. The encapsulation efficiency of quercetin in the O/W emulsions was 80% at 4 °C and 70% at 25 °C during the evaluated storage period.

Monodisperse aqueous microspheres encapsulating high concentration of l-ascorbic acid: insights of preparation and stability evaluation from straight-through microchannel emulsification

Stabilization of l-ascorbic acid (⌊-AA) is a challenging task for food and pharmaceutical industries. The study was conducted to prepare monodisperse aqueous microspheres containing enhanced concentrations of ⌊-AA by using microchannel emulsification (MCE). The asymmetric straight-through microchannel (MC) array used here constitutes 11 × 104 μm microslots connected to a 10 μm circular microholes. 5-30% (w/w) ⌊-AA was added to a Milli-Q water solution containing 2% (w/w) sodium alginate and 1% (w/w) magnesium sulfate, while the continuous phase constitutes 5% (w/w) tetraglycerol condensed ricinoleate in water-saturated decane. Monodisperse aqueous microspheres with average diameters (dav) of 18.7-20.7 μm and coefficients of variation (CVs) below 6% were successfully prepared via MCE regardless of the ⌊-AA concentrations applied. The collected microspheres were physically stable in terms of their dav and CV for >10 days of storage at 40°C. The aqueous microspheres exhibited ⌊-AA encapsulation efficiency exceeding 70% during the storage.

Formulation of monodisperse oil-in-water emulsions loaded with ergocalciferol and cholecalciferol by microchannel emulsification: Insights of production characteristics and stability

Nutritional deficiencies of ergocalciferol (VD2) and cholecalciferol (VD3) cause skeletal deformations. The primary aim of this study was to encapsulate VD2 and VD3 in food-grade oil-in-water (O/W) emulsions by using microchannel emulsification (MCE). Silicon asymmetric straight-through microchannel (MC) array consisting of 10 313 channels, each having an 11 × 104 μm microslot connected to a 10 μm circular microholes. 1% (w/w) sodium cholate or Tween 20 in water was used as the continuous phase, while 0.5% (w/w) of each VD2 and VD3 in different oils served as the dispersed phase. Monodisperse O/W emulsions with Sauter mean diameters of 28 to 32 μm and relative span factor widths below 0.3 were formulated via an asymmetric straight-through MC array under appropriate operating conditions. The monodisperse O/W emulsions stabilised with Tween 20 remained stable for >30 days with encapsulation efficiencies (EEs) of VD2 and VD3 of above 70% at 4 and 25 °C. In contrast, those stabilised with sodium cholate had stability of >30 days with their EEs of over 70% only at 25 °C.

Preparation of monodisperse aqueous microspheres containing high concentration of L-ascorbic acid by microchannel emulsification

Monodisperse aqueous microspheres containing high concentrations of l-ascorbic acid with different concentrations of sodium alginate (Na-ALG) and magnesium sulfate (MgSO4) were prepared by using microchannel emulsification (MCE). The continuous phase was water-saturated decane containing a 5% (w/w) hydrophobic emulsifier. The flow rate of the continuous phase was maintained at 10 mL h(-1), whereas the pressure applied to the disperse phase was varied between 3 and 25 kPa. The disperse phase optimized for successfully generating aqueous microspheres included 2% (w/w) Na-ALG and 1% (w/w) MgSO4. At a higher MgSO4 concentration, the generated microspheres resulted in coalescence and subsequent bursting. At a lower MgSO4 concentration, unstable and polydisperse microspheres were obtained. The aqueous microspheres generated from the MCs under optimized conditions had a mean particle diameter (dav) of 14-16 µm and a coefficient of variation (CV) of less than 8% at the disperse phase pressures of 5-15 kPa.

Formulation characteristics of triacylglycerol oil-in-water emulsions loaded with ergocalciferol using microchannel emulsification

Ergocalciferol is one important form of vitamin D that is needed for proper functioning of the human metabolic system. The study formulates monodisperse food grade ergocalciferol loaded oil-in-water (O/W) emulsions by microchannel emulsification (MCE). The primary characterization was performed with grooved MCE, while the storage stability and encapsulating efficiency (EE) were investigated with straight-through MCE. The grooved microchannel (MC) array plate has 5 × 18 μm MCs, while the asymmetric straight-through MC array plate consists of numerous 10 × 80 μm microslots each connected to a 10 μm diameter circular MC. Ergocalciferol at a concentration of 0.2-1.0% (w/w) was added to various oils and served as the dispersed phase, while the continuous phase constituted either of 1% (w/w) Tween 20, decaglycerol monolaurate (Sunsoft A-12) or β-lactoglobulin. The primary characterization indicated successful emulsification in the presence of 1% (w/w) Tween 20 or Sunsoft A-12. The average droplet diameter increased slowly with the increasing concentration of ergocalciferol and ranged from 28.3 to 30.0 μm with a coefficient of variation below 6.0%. Straight-through MCE was conducted with 0.5% (w/w) ergocalciferol in soybean oil together with 1% (w/w) Tween 20 in Milli-Q water as the optimum dispersed and continuous phases. Monodisperse O/W emulsions with a Sauter mean diameter (d3,2) of 34 μm with a relative span factor of less than 0.2 were successfully obtained from straight-through MCE. The resultant oil droplets were physically stable for 15 days (d) at 4 °C without any significant increase in d3,2. The monodisperse O/W emulsions exhibited an ergocalciferol EE of more than 75% during the storage period.

Formulation of monodisperse water-in-oil emulsions encapsulating calcium ascorbate and ascorbic acid 2-glucoside by microchannel emulsification

The aim of this study was to investigate the effects of the emulsifying conditions and emulsifier type on production of water-in-oil (W/O) emulsions encapsulating ascorbic acid derivatives by microchannel (MC) emulsification. The ascorbic acid derivatives added in a dispersed aqueous phase are calcium ascorbate (AA-Ca) and ascorbic acid 2-glucoside (AA-2G). The continuous phase used was decane, soybean oil or their mixture, containing 5% (w/w) tetraglycerin monolaurate condensed ricinoleic acid ester or sorbitan trioleate. A hydrophobized silicon MC array plate (model: MS407) with a channel depth of 7μm was used for MC emulsification. The use of MC emulsification enabled successful encapsulation of AA-Ca and AA-2G in monodisperse W/O emulsion droplets with coefficients of variation (CV) less than 7%. Their average droplet diameter (dav) increased with increasing the continuous-phase viscosity that is similar or higher than the dispersed-phase viscosity. The dav and CV of the resultant monodisperse W/O emulsions were unaffected by the dispersed-phase flow rate below critical values of 1.2-1.6mLh-1 when using decane as the continuous-phase medium.

Monodisperse W/O/W emulsions encapsulating L-ascorbic acid: Insights on their formulation using microchannel emulsification and stability studies

Stabilizing l-ascorbic acid is a challenge for food industries. The present study aimed to formulate monodisperse food-grade water-in-oil-in-water (W/O/W) emulsions containing a high concentration of l-ascorbic acid in an inner aqueous phase using homogenization and subsequent microchannel emulsification (MCE). The microchannel (MC) array plate used here was a silicon asymmetric straight-through MC array that consists of numerous 10. μm. ×. 100. μm microslots with a 30. μm depth, each connected to a 10. μm-diameter circular MC with a 70. μm depth. Water-in-oil (W/O) emulsions contained a soybean oil solution with 4-8% (w/w) tetraglycerin condensed ricinoleic acid ester as a continuous phase and an aqueous solution with 10-30% (w/v) l-ascorbic acid, 1% (w/w) magnesium sulfate, and 1% (w/v) gelatin as an inner aqueous phase. The W/O emulsion droplets formulated using a rotor-starter homogenizer had average droplet diameters of 2.6-2.9. μm and coefficients of variation (CVs) of 13-17%. MCE was performed using a dispersed W/O emulsion phase and a 5. mM phosphate buffer containing 1% (w/w) decaglycerol monolaurate and 10-30% (w/v) D(+)-glucose as an outer aqueous phase. Monodisperse W/O/W emulsions containing W/O droplets with average diameters of 26.0-31.5. μm and CVs below 10% were successfully formulated via an asymmetric straight-through MC array at a low hydrophobic emulsifier concentration, regardless of l-ascorbic acid concentration. The W/O droplets dispersed in these monodisperse W/O/W emulsions were physically stable in variation of average diameter and CV for more than 10d of storage at 4. °C. The monodisperse W/O/W emulsions also exhibited l-ascorbic acid retention exceeding 80% during storage.

Protein quality and physico-functionality of Australian sweet lupin (Lupinus angustifolius cv. Gungurru) protein concentrates prepared by isoelectric precipitation or ultrafiltration

The protein quality and physico-functional properties of Australian sweet lupin protein concentrates, prepared by isoelectric precipitation or ultrafiltration, were assessed. The ultrafiltration process resulted in a higher yield of protein than did the isoelectric precipitation process. The lupin kernel and the two lupin protein concentrates had similar essential amino acid compositions that were inferior to ideal human requirements. True digestibilities of the isoelectrically precipitated (ISO) and the ultrafiltered (UF) lupin protein concentrates were similar but significantly higher (P<0.05) than that of casein. Net protein utilisations (NPU) of the ISO and UF protein concentrates were similar but significantly lower (P<0.05) than that of casein. The UF protein concentrate had higher protein solubility than did the ISO protein concentrate (P<0.05). Low foaming capacity, low viscosity, but high emulsification capacity (particularly at low pH) were observed for lupin protein concentrates.

Complex coacervation with whey protein isolate and gum arabic for the microencapsulation of omega-3 rich tuna oil.

Tuna oil rich in omega-3 fatty acids was microencapsulated in whey protein isolate (WPI)-gum arabic (GA) complex coacervates, and subsequently dried using spray and freeze drying to produce solid microcapsules. The oxidative stability, oil microencapsulation efficiency, surface oil and morphology of these solid microcapsules were determined. The complex coacervation process between WPI and GA was optimised in terms of pH, and WPI-to-GA ratio, using zeta potential, turbidity, and morphology of the microcapsules. The optimum pH and WPI-to-GA ratio for complex coacervation was found to be 3.75 and 3 : 1, respectively. The spray dried solid microcapsules had better stability against oxidation, higher oil microencapsulation efficiency and lower surface oil content compared to the freeze dried microcapsules. The surface of the spray dried microcapsules did not show microscopic pores while the surface of the freeze dried microcapsules was more porous. This study suggests that solid microcapsules of omega-3 rich oils can be produced using WPI-GA complex coacervates followed by spray drying and these microcapsules can be quite stable against oxidation. These microcapsules can have many potential applications in the functional food and nutraceuticals industry.