Changes in lipid compositions of krill oil emulsions during storage, a role of ultrasound treatment and the possible process of lipid migration

Abstract

The changes in lipid compositions of krill oil emulsions during storage were investigated, as well as the role of ultrasound treatment. Whey protein isolate (WPI) was used as wall materials to krill oil, which was treated with ultrasound. The effects of WPI concentration (from 0.2% to 10%), ultrasound power (from 10% to 80%) and treatment (at the same energy density with different power) were evaluated. Storage stability of different emulsions was characterised appearance, particle sizes, zeta potential, polydispersity index and microstructures. The lipid compositions and interactions were analysed to debate the changes of emulsions. The results indicated that ultrasound increased the stability of emulsions, enhanced the hydrophobic interactions between WPI and lipids and kept lipid composition distributions in each layer of emulsions. Furthermore, a possible mechanism of lipid migration in krill oil emulsions was put forward. The study will assist in the application and mechanism of krill oil emulsions treated with ultrasound.

Advances in encapsulation systems of Antarctic krill oil: From extraction to encapsulation, and future direction

“…Whey isolate protein can form emulsion with AKO by low speed mixing, and under the action of ultrasound, it leaks more hydrophobic groups, which increases the hydrophobic interaction with AKO, reduces the particle size of emulsion, and improves emulsion stability (Wang, Zhao, Liu, et al., 2022). Antarctic krill protein subjected to alkali extraction and acid precipitation from defatted Antarctic krill meal, mixed with AKO, and homogenized to obtain an emulsion that could be placed for one week at 4°C without phase separation, and this method also improve the utilization of krill by‐products (Shi et al., 2018).…”

“…In the preparation of AKO emulsion, amphiphilic proteins are unfolded at the oil‐water interface, where hydrophilic groups are bound to water and hydrophobic groups are bound to and encapsulated in AKO to form water‐in‐oil emulsions. Commonly used proteins include casein (Wang, Zhao, Zhang, et al., 2022), whey protein isolate (Wang, Zhao, Liu, et al., 2022), Antarctic krill protein (Shi et al., 2018), chickpea protein isolate (Xu et al., 2021), and myofibrillar protein (Wang, Liu, Ma, Yang, et al., 2020) etc.…”

Encapsulation of Antarctic krill oil and kaempferol co‐loaded nano‐liposomes in alginate‐chitosan hydrogel beads: improved stability and modified digestive behaviour

“…(Huang et al ., 2019; Lin et al ., 2022). Emulsions were used to deliver krill oil and keep its stability, but emulsion preparation requires many emulsifiers (Wang et al ., 2022). Microencapsulation techniques have been utilised to encapsulate marine oils, but microencapsulation improved the oxidative stability of marine oils only within 14 days, long‐term storage being limited (Sun & Xia, 2019; Fu et al ., 2022).…”