Emulsions in diet

Emulzije su disperzni sustavi prisutni u brojnim prehrambenim proizvodima. Razlikujemo tri vrste emulzija: emulzija tipa voda u ulju V/U, emulzija tipa ulje u vodi U/V te višestruke emulzije. Izgled emulzije ovisi o raspršivanju, apsorpciji, reflektiranju i prolazu elektromagnetskih valova vidljive svjetlosti. Procese emulgiranja djelimo na metode visoke i niske energije u koje se ubrajaju ultrazvučno emulgiranje, mikrofluidizacija, homogenizacija pod visokim tlakom, homogenizacija velikom brzinom, temperaturna inverzija faza i sastav inverzije faza. Na stabilnost emulzije utječu njezini sastojci i načini proizvodnje. Mehanizmi nestabilnosti su koalescencija, flokulacija, taloženje, Ostwaldovo zrenje i inverzija faza. Emulgatori su površinski aktivne tvari koje stabiliziraju emulzije. Vrste emulgatora su fosfolipidi, bioemulgatori, proteini i polisaharidi koji se zbog svoje amfifilne prirode adsorbiraju na sučeljima i ulja i vode. Mlijeko, mliječni proizvodi, preljevi i neka pića prehrambeni su proizvodi koji su primjeri emulzija, najčešće tipa U/V.Emulsions are disperse systems present in a number of food products. There are different types of emulsions: water-in-oil emulsion W/O, oil-in-water O/W emulsion and multiple emulsions. The appearance of the emulsion depends on the dispersion, absorption, reflection and transmission of light waves in the visible region of the electromagnetic spectrum. Emulsification methods are divided into high and low energy methods, which include ultrasonic emulsification, microfluidization, high pressure homogenization, high speed homogenization, temperature inversion of phases and phase inversion composition. The stability of an emulsion is affected by its ingredients and production methods. The mechanisms of instability are coalescence, flocculation, sedimentation, Ostwald ripening, and inversion phases. Emulsifiers stabilize emulsions. Types of emulsifiers are phospholipids, bioemulsifiers, proteins and polysaccharides which, due to their amphiphilic nature, are adsorbed on the interfaces of both oils and water. Milk, dairy products, dressings and some beverages are food products that are examples of emulsions, most often emulsion type U/ W