Naslov
Optimization of Bleaching Parameters for Soybean Oil

Autori
Škevin, Dubravka ; Domijan, Tomislav ; Kraljić, Klara ; Gajdoš Kljusurić, Jasenka ; Neđeral, Sandra ; Obranović, Marko

Izvornik
Food technology and biotechnology (1330-9862) 50 (2012), 2; 199-207

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
bleaching; soybean oil; oxidative stability; sterols; tocopherols

Sažetak
The final stage of edible soybean oil manufacture is refining, the most delicate phase of which is bleaching. At this step, undesirable substances are removed, such as pigments, traces of metals and phospholipids and certain degradation products. However, certain valuable compounds such as tocopherols and sterols may also be removed, significant loss of oxidative stability can occur, and fatty acid content may increase. To avoid these negative oil changes, bleaching parameters such as concentration of bleaching clay, temperature and duration should be optimized. Since bleaching conditions depend on the properties of the bleaching clay as well as the type of crude oil, bleaching parameters should be optimized with different clays for each vegetable oil. Since such optimization has not yet been reported for soybean oil with Supreme Flo-Active, this study investigates the effect of bleaching parameters on bleaching efficiency, oxidative stability and the content and composition of bioactive compounds (tocopherols and sterols) with above mentioned clay in this type of oil. Results show that clay amount had the greatest influence on bleaching efficiency, especially according to the Lovibond scale, on transparency, and on phosphorus content. Temperature and clay amount significantly affected oxidative stability, in particular the formation of secondary oxidation products. Increasing clay amount decreased tocopherol content of the bleached oil. Neutralized soybean oil bleached for 20 minutes at 95 °C with 1 % Supreme Flo-Active bleaching clay showed the highest oxidative stability, best bleaching efficiency, and most favorable sterol content, although tocopherol content was reduced.

Izvorni jezik
Engleski

Znanstvena područja
Prehrambena tehnologija

POVEZANOST RADA