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This study aims to develop an experimentally validated three-dimensional numerical model for predicting different flow patterns produced with a gas dynamic virtual nozzle (GDVN).

The physical model is posed in the mixture formulation and copes with the unsteady, incompressible, isothermal, Newtonian, low turbulent two-phase flow. The computational fluid dynamics numerical solution is based on the half-space finite volume discretisation. The geo-reconstruct volume-of-fluid scheme tracks the interphase boundary between the gas and the liquid. To ensure numerical stability in the transition regime and adequately account for turbulent behaviour, the k-ω shear stress transport turbulence model is used. The model is validated by comparison with the experimental measurements on a vertical, downward-positioned GDVN configuration. Three different combinations of air and water volumetric flow rates have been solved numerically in the range of Reynolds numbers for airflow 1,009–2,596 and water 61–133, respectively, at Weber numbers 1.2–6.2.

The half-space symmetry allows the numerical reconstruction of the dripping, jetting and indication of the whipping mode. The kinetic energy transfer from the gas to the liquid is analysed, and locations with locally increased gas kinetic energy are observed. The calculated jet shapes reasonably well match the experimentally obtained high-speed camera videos.

The model is used for the virtual studies of new GDVN nozzle designs and optimisation of their operation.

To the best of the authors’ knowledge, the developed model numerically reconstructs all three GDVN flow regimes for the first time.

The purpose of this study is to address consumer’s preference of natural pigments over synthetic ones and their use in various product developments rather than using synthetic colours. A budding interest of using natural pigments has made researchers to explore several techniques for their stabilization and application in different food products.

In this review, four major natural pigments with potential health benefits have been studied. Betalins, carotenoids, anthocyanins and chlorophylls, in spite of having excellent bio-functional and therapeutic profile, are found to be unstable. Therefore, various nanoencapsulation techniques are used to increase their stability along with their therapeutic properties.

Nanoencapsulation of natural pigments improves their stability, their effect on therapeutic properties and their application in different food products. These findings could be attributed to the encapsulating material as it acts as a barrier and ushers changes in the matrix of natural pigments. Also, nanoencapsulation not only increases stability but also provides several health benefits such as anti-inflammation, anti-cancer, anti-allergic and anti-thrombotic properties.

This paper highlights the openings for the use of nanoencapsulation of natural pigments to stabilize them and use them as a potential colourant and functional ingredient in different food products. Phenols, carotenoids and antioxidant activity are the major factors that are responsible for promoting several health benefits.