Effect of manufacture and reconstitution of milk protein concentrate powder on the size and rennet gelation behaviour of casein micelles

Samples of raw skim milk, ultrafiltration/diafiltration retentate, concentrated retentate and milk protein concentrate powder (MPC80) from a single commercial production run were analysed using photon correlation spectroscopy. Measurements revealed insignificant differences in casein micelle size between the samples. In addition, there was no discernable difference between raw skim milk and MPC powder dissolved at 60 °C in the amount of casein remaining in supernatants from centrifugation at either 25,000 × g or 174,200 × g. Casein micelles did not appear to be altered during manufacture of MPC. The rennet gelation behaviour of reconstituted MPC was compared with raw skim milk. Reconstituted MPC did not coagulate unless supplemented with approximately 2 mm calcium chloride, which was attributed to the mineral removal during ultrafiltration/diafiltration. Addition of sufficient calcium could restore rennet coagulation kinetics and gel strength of reconstituted MPC to approximately that of raw skim milk.     

Continuous Synthesis of Tin and Indium Oxide Nanoparticles in Sub- and Supercritical Water

Nanocrystalline tin and indium oxides (In₂O₃/SnO₂) were synthesized in sub- and supercritical water at 350°/380°C and 30 MPa in <73 s in a tubular flow reactor from an aqueous solution of {SnCl₄+InCl₃} (0.2 M ). The conversion rate for tin was 100%. Nanoparticles were analyzed by transmission electron microscopy (TEM), emitted X-rays, Raman, differential scanning calorimetry, and X-ray diffraction techniques. The bulk particles were composed of In, Sn, and O atoms, and made up of cubic In₂O₃ (10 nm) and tetragonal SnO₂ (5.5 nm) crystals. After calcination at 500°C for 2 h, little change occurred in the particle size and crystal phase. Traces of tin-doped indium oxide particles were also formed as confirmed by the TEM electron diffraction pattern. Using this one-step, high-temperature hydrothermal process, oxide nanoparticles can be continuously and conveniently produced in a well-controlled process.     

Synthetic elevation beamforming and image acquisition capabilities using an 8 x 128 1.75D array

Ultrasound imaging can be improved with higher order arrays through elevation dynamic focusing in future, higher channel count systems. However, modifications to current system hardware could yield increased imaging depth-of-field with 1.75D arrays (arrays with individually addressable elements, several rows in elevation) through the use of synthetic elevation imaging. We describe synthetic elevation beamforming methods and its implementation with our 8 /spl times/ 128, 1.75D array (Tetrad Co., Englewood, CO). This array has been successfully interfaced with a Siemens Elegra scanner for summed RF and single channel RF data acquisition. Individual rows of the 8 /spl times/ 128 array can be controlled, allowing for different aperture configurations on transmit and receive beamforming. Advantages of using this array include finer elevation sampling, a larger array footprint for aberration measurements, and elevation focusing. We discuss system tradeoffs that occur in implementing synthetic receive and synthetic transmit/receive elevation focusing and show significant image quality improvements in simulation and phantom data results.     

Control centric approach in designing scrolling and zooming user interfaces

The dynamic systems approach to the design of continuous interaction interfaces allows the designer to use simulations, and analytical tools to analyse the behaviour and stability of the controlled system alone and when it is coupled with a manual control model of user behaviour. This approach also helps designers to calibrate and tune the parameters of the system before the actual implementation, and in response to user feedback. In this work we provide a dynamic systems interpretation of the coupling of internal states involved in speed-dependent automatic zooming, and test our implementation on a text browser on a Pocket PC instrumented with a tilt sensor. We illustrate simulated and experimental results of the use of the proposed coupled navigation and zooming interface using tilt and touch screen input.     

On the interpretation of local models in blended multiple model structures

The construction of non-linear dynamics by means of interpolating the behaviour of locally valid models offers an attractive and intuitively pleasing method of modelling non-linear systems. The approach is used in fuzzy logic modelling, operating regime based models, and non-linear statistical models. The model structure suggests that the composite local models can be used to interpret, in some appropriate manner, the overall non-linear dynamics. In this paper we demonstrate that the interpretation of these local models, in the context of multiple model structures, is not as straightforward as it might initially appear. We argue that the blended multiple model system can be interpreted in two ways as an interpolation of linearizations, or as a full parameterization of the system. The choice of interpretation affects experiment design, parameter identification, and model validation. We then show that, in some cases, the local models give insight into full model behaviour only in a very small region of state space. More alarmingly, we demonstrate that for off-equilibrium behaviour, subject to some approximation error, a non-unique parameterization of the model dynamics exists. Hence, qualitative conclusions drawn from the behaviour of an identified local model, e.g. regarding stable, unstable, nodal or complex behaviour, must be treated with extreme caution. The example of muscle modelling is used to illustrate these points clearly.     

Elevated production of the aromatic fragrance molecule, 2‐phenylethanol,using Metschnikowia pulcherrima through both de novo and ex novo conversion in batch and continuous modes

BACKGROUND

2‐phenylethanol (2PE) is a fragrance molecule predominantly used in perfumes and the food industry. It can be made from petrochemicals inexpensively, however, this is unsuitable for most food applications. Currently, the main method of production for the bio‐derived compound is to extract the trace amounts found in rose petals, which is extremely costly. Potentially fermentation could provide an inexpensive, naturally sourced, alternative.

RESULTS

In this investigation, 2PE was produced from the yeast Metschnikowia pulcherrima, optimised in flasks before scaling to 2 L batch and continuous operation. 2PE can be produced in high titres under de novo process conditions with up to 1500 mg L^?1 achieved in a 2 L stirred bioreactor. This is the highest reported de novo titre to date, and achieved through high sugar loadings coupled with low nitrogen conditions. The process successfully ran in continuous mode also, with a concentration of 650 mg L^?1 of 2PE being maintained. The 2PE production was further increased by the ex novo conversion of phenylalanine and semi‐continuous solid phase extraction from the supernatant. Under optimal conditions 14 000 mg L^?1 of 2PE was produced.

CONCLUSIONS

The work presented here offers a novel route to naturally sourced 2PE through a scalable fermentation with a robust yeast highly suited to industrial biotechnology. © 2018 The Authors. Journal of Chemical Technology & Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.