Protein cold-set gels are potential carriers for the encapsulation of bioactive compounds.Meanwhile,bioactive compounds have also been used as cross-linkers or accessories for protein gelation,but their encapsulation ...Protein cold-set gels are potential carriers for the encapsulation of bioactive compounds.Meanwhile,bioactive compounds have also been used as cross-linkers or accessories for protein gelation,but their encapsulation has not been investigated during gelation for potential nutritional value.In this study,cold-set gels of whey protein isolate(WPI)were induced by L-ascorbic acid(L-AA)at pH 4.0-6.0,L-ascorbic acid plus CaCl_(2) at pH 3.8,or Lascorbic calcium at pH 7.0.The range of pH for WPI gelation induced by L-AA narrowed with the decrease of WPI content from 10% to 6%(w/v).The gel networks were stabilized by non-covalent and covalent interactions,which difference was dependent on the use of cross-linkers.L-Ascorbic recoveries were above 76% in WPI hydrogels,where the highest recovery reached 98%.L-Ascorbic encapsulation efficiency ranged from 69% to 100%.Hydrogels and cyrogels varied from a smooth and dense structure to a coarse structure.L-ACa at 16 mM induced uniform and compact structure of both gels and the highest hardness and storage modulus of hydrogel.L-Ascorbic groups were effectively immobilized into WPI gels via their interaction with whey protein and calcium.L-Ascorbic loading capacity in WPI hydrogels and gel powder increased as the pH decreased and its calcium concentration increased.The release of free L-ascorbic acid from gel powder was independent on protein rehydration.These results suggest the potential use of protein cold-set gels for the encapsulation and delivery of bioactive compounds with themselves or their combination with calcium as cross-linkers.展开更多
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 t...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.展开更多
文摘Protein cold-set gels are potential carriers for the encapsulation of bioactive compounds.Meanwhile,bioactive compounds have also been used as cross-linkers or accessories for protein gelation,but their encapsulation has not been investigated during gelation for potential nutritional value.In this study,cold-set gels of whey protein isolate(WPI)were induced by L-ascorbic acid(L-AA)at pH 4.0-6.0,L-ascorbic acid plus CaCl_(2) at pH 3.8,or Lascorbic calcium at pH 7.0.The range of pH for WPI gelation induced by L-AA narrowed with the decrease of WPI content from 10% to 6%(w/v).The gel networks were stabilized by non-covalent and covalent interactions,which difference was dependent on the use of cross-linkers.L-Ascorbic recoveries were above 76% in WPI hydrogels,where the highest recovery reached 98%.L-Ascorbic encapsulation efficiency ranged from 69% to 100%.Hydrogels and cyrogels varied from a smooth and dense structure to a coarse structure.L-ACa at 16 mM induced uniform and compact structure of both gels and the highest hardness and storage modulus of hydrogel.L-Ascorbic groups were effectively immobilized into WPI gels via their interaction with whey protein and calcium.L-Ascorbic loading capacity in WPI hydrogels and gel powder increased as the pH decreased and its calcium concentration increased.The release of free L-ascorbic acid from gel powder was independent on protein rehydration.These results suggest the potential use of protein cold-set gels for the encapsulation and delivery of bioactive compounds with themselves or their combination with calcium as cross-linkers.
文摘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.
