Emulsions as Colloidal Systems

Sustavi u kojima je jedna tvar raspršena u drugoj nazivaju se disperzni sustav, a njihova podjela ovisi o veličini čestica. Koloidi su podvrsta disperznih sustava čija se veličina čestica kreće od 1 do 100 nm. Jedan od primjera koloidnih sustava su emulzije u kojima je jedna tekućina raspršena u drugoj. Postoje dva tipa emulzija ulje u vodi i voda u ulju. Svojstva emulzija određena su prema veličini kapljica raspršene disperzne faze, sastavu i svojstvima površinskog omotača kapljica i sastavu kontinuirane faze. Kapljice u emulzijama su uglavnom sferične i podložne deformiranju. Neke od nestabilnosti emulzija su izdvajanje kapljica na površinu, agregacija, koalescencija. Kako bi se stvorila emulzija i osigurala njena stabilnost, koriste se emulgatori. Emulzije su zastupljene u prehrambenoj industriji. Cilj ovog rada je definirati disperzne sustave te koloidne sustave, opisati podjelu koloida te svojstva koloida, definirati emulzije, stvaranje emulzija, pojave na dodirnoj površini tekućina – tekućina, utjecaj emulgatora na emulzije i njihovu stabilnost. Osim toga, cilj je prikazati neke od primjera emulzija u prehrambenoj industriji.Systems in which one type of particles is dispersed in another is referred to as a dispersion system. Their classification depends on the particle size. Colloids are a subtype of dispersion systems whose particle size range from 1 to 100 nm. One example of colloidal systems are emulsions in which one liquid is scattered in another. There are two types of emulsions; oil emulsions in water and water in the oil. Emulsion properties are determined by the size of the dispersed droplet, the composition and properties of the droplet surface layer and the composition of the continuous phase. Droplets in emulsions are generally spherical and subject to deformation. Some of the instability of emulsions are the separation of droplets on the surface, aggregation or coalescence. In order to create an emulsion and ensure its stability, emulsifiers are used. Emulsions are represented in the food industry. The aim of this paper is to define dispersion systems and colloid systems, to describe the classification of colloids and colloid properties, to define emulsions, creation of emulsions, phenomena on the liquid – liquid inteface, the effect of emulsifiers on emulsions and their stability. In addition, the aim is to present some examples of emulsions in the food industry