Characteristics,formation mechanism and stability of high internal phase emulsions stabilized by porcine plasma protein (PPP) / carrageenan (CG) hybrid particles

High internal phase emulsions (HIPEs) stabilized by nanoparticles based on biomacromolecules are challenging issues in recent decade.Herein,a newly developed HIPE was investigated by using heat-denatured porcine plasma protein (PPP) nanoparticles at pH 6.5 as emulsifier,and its emulsifying stability could be significantly enhanced by compounding carrageenan (CG).In the miscible system,PPP and CG formed hybrid particles through non-covalent interaction,and the sizes and zeta-potentials of the particles increased significantly along with addition of CG (from 0 to 0.7%,w/v),reached up to about 3.6 μm and −53 mV at 0.5% (w/v),respectively.CG weakened the ability of PPP to lower interfacial tension of oil/water (O/W),but increased the apparent viscosity of the system.The results from CLSM,rheology and stability experiments indicated a significant increasing trend of the HIPEs stability and solid-like characteristics along with addition of CG.Compared with the controls including bovine serum albumin (BSA),BSA-CG and CG alone,PPP-CG hybrid particles had good performance in fabricating and stabilizing the HIPEs.The work revealed the novel function of PPP as emulsifier of HIPEs and so offered the theoretical direction for application of PPP as a mass by-product,as well as an excellent HIPEs system for food,medicine and cosmetics fields.

Protective,controlled-release and embedding mechanism of porcine plasma protein cold-set gel on quercetin:An effective carrier of hydrophobic compounds

Protection and embedding of hydrophobic bioactive compounds using protein hydrogels are emerging focus during the latest decade.In present study,we fabricated the porcine plasma protein(PPP)cold-set gel by microbial transglutaminase(MTGase)and glucono-δ-lactone(GDL)as coupling precursors.As a result,the embedding,protection and controlled-release effect of the gel on vulnerable hydrophobic bioactive components(quercetin(Que)as representative)with proposed molecular mechanisms were investigated in detail.The results showed that high concentration of Que(5 mmol/L)could be loaded with PPP cold-set gel and embedding efficiency(EE)was over 98%.Compared with free Que,the embedded one exhibited significantly higher thermostability,photochemical stability and storage stability(P<0.05).In addition,the gel loaded with 5 mmol L^(−1) of Que had higher swelling potency under gastric(low pH)media and controlled release performance following simulated intestinal digestive pathway.Water holding capacity(WHC)implied that free water molecules played less role in the retention ability of Que in fabricated gel network.Spectral-assisted structural characterization proved that Que was efficiently embedded mainly by generating PPP-Que complex through hydrogen bond and van der Waals force,and the binding site was mainly near Trp residue.This work gave novel insight into the potential use of PPP cold-set gel as an excellent carrier towards protection and selective delivery of vulnerable small hydrophobic nutraceutical compounds.