Utjecaj velikih i malih molekula emulgatora na svojstva nanoemulzija β-karotena, pripremljenih homogenizacijom pod visokim pritiskom - Mao, Like; College of Food Science and Nutritional Engineering, China Agricultural University, CN-100083 Beijing, PR China; Xu, Duoxia; College of Food Science and Nutritional Engineering, China Agricultural University, CN-100083 Beijing, PR China; Yang, Jia; College of Food Science and Nutritional Engineering, China Agricultural University, CN-100083 Beijing, PR China; Yuan, Fang; College of Food Science and Nutritional Engineering, China Agricultural University, CN-100083 Beijing, PR China; Gao, Yanxiang; College of Food Science and Nutritional Engineering, China Agricultural University, CN-100083 Beijing, PR China; gyxcau@126.com; Zhao, Jian; School of Chemical Sciences and Engineering, The University of New South Wales, Sydney, NSW 2052, Australia (Faculty of Food Technology and Biotechnology, University of Zagreb; imacan@pbf.hr, 2009)
Nanoemulzije ulja u vodi omogućuju pripremu lipofilnih hranjivih tvari, kao što su karotenoidi u tekućem obliku, čime se povećava njihova biološka pristupačnost i primjena. U radu je istražena mogućnost pripreme nanoemulzija β-karotena pomoću ovih emulgatora: polioksietilen sorbitan monolaurata (Tween 20), dekaglicerol monolaurata, škrob natrijeva oktenil sukcinata, izolata pšeničnih proteina i 1 %-tne smjese Tween 20 i izolata pšeničnih proteina. Uspoređena je međupovršinska napetost dobivenih emulzija, veličina kapljica, zeta- potencijal, mikrostruktura (utvrđena pomoću mikroskopa atomskih sila), te stabilnost emulzija i β-karotena. Rezultati pokazuju da nanoemulzije stabilizirane s Tween 20 i dekaglicerol monolauratom imaju manje kapljice, ali slabiju stabilnost od emulzija stabiliziranih sa škrob natrijevim oktenil sukcinatom i izolatom pšeničnih proteina (p<0,05). Ispitivanjem emulzija skladištenih 12 dana na temperaturi od 55 °C utvrđeno je da izolat pšeničnih proteina, za razliku od škrob natrijeva oktenil sukcinata, učinkovito štiti β-karoten od degradacije. Stabilnost nanoemulzija znatno se povećala primjenom smjese Tween 20 i izolata pšeničnih proteina (p<0,05), ali ta smjesa nije bitno utjecala na stabilnost β-karotena u emulzijama (p>0,05). Oil-in-water (O/W) nanoemulsion allows the preparation of lipophilic nutrients such as carotenoids in liquid form, which may improve their bioavailability and broaden applications. In the present study, polyoxyethylene sorbitan monolaurate (Tween 20, TW-20), decaglycerol monolaurate (DML), octenyl succinate starch (OSS), whey protein isolate (WPI), and finally a blend of TW-20 and WPI (1 % by mass) have been tested for the preparation of β-carotene nanoemulsions. Interfacial tension, droplet size, zeta potential, microstructures observed by atomic force microscopy (AFM), stability of the emulsion and β-carotene have been compared. Results show that nanoemulsions stabilized with TW-20 and DML had smaller droplet size, but relatively poorer stability, compared with the ones stabilized with OSS and WPI (p<0.05). WPI was able to protect β-carotene effectively from degradation, whereas OSS was not when emulsions were stored at 55 °C for 12 days. When a blend of TW-20 and WPI was used, the stability of nanoemulsions was significantly improved (p<0.05). However, no significant effect of the mixed emulsifiers was found on the stability of β-carotene in the emulsions (p>0.05).