12 January - 20 June 2016

Effects of surface treatment and storage conditions of silicon microchannel emulsification on preparation of oil emulsion droplets

21 October 2015

Emulsions are fat based liquid structures formed by mixing two immiscible liquids, used commonly in the food industry for products such as sauces and spreads. Smaller oil droplets within the emulsion enhance perceived creaminess, and give an increased sensation of satiety for consumers. Traditional food emulsification is carried out by homogenisers and colloid mills, but a new technique of ‘microchannel emulsification’ through silicon plates has recently been introduced. However, one of its drawbacks is difficulty in producing stable monodisperse emulsions through plates that have been stored for a long period of time.

A study by the Food Engineering Division of the National Food Research Institute, Japan, analysed the effect of the storage conditions of silicon microchannel array plates on their surface properties and microchannel emulsification. The array plates were treated with oxygen plasma to make them hydrophilic and then stored in different conditions: air, nitric acid, and Milli-Q water at different temperatures. The analysts found that the surface-treated silicon microchannel array plates lost their hydrophilicity over time, which is influenced by the variables of medium and temperature. As air is hydrophobic, its chemical composition causes an interaction with the plate array to make it lose its hydrophilicity. Although nitric acid is a hydrophilic fluid, molecules of nitric acid were ionized into nitrate and hydrogen ions. The hydrogen ions and silanol groups formed on the plate surface, again affecting hydrophilicity. The most desired outcome came from Milli-Q water, because it is a hydrophilic fluid with a lower concentration of dissociated hydrogen ions than nitric acid. Furthermore, it was found that low temperature storage (5°c) slowed down the dissociation rate of the hydrophilicity of the microchannel array plates as compared to storage temperatures of 25°c and 50°c. Hydrophilicity of the microchannel array plate is then linked to the manufacture of emulsions by creating a more monodisperse food-grade emulsion on a more hydrophilic medium.

share this article
RSSL endeavours to check the veracity of news stories cited in this free e-mail bulletin by referring to the primary source, but cannot be held responsible for inaccuracies in the articles so published. RSSL provides links to other World Wide Web sites as a convenience to users, but cannot be held responsible for the content or availability of these sites. This document may be copied and distributed provided the source is cited as RSSL's Food e-News and the information so distributed is not used for profit.

Previous editions

Load more editions

Make an Enquiry