As a kind of biopolymer,hydrolysates of fish swim bladder,safer than those of land mammals,are widely used in food,cosmetics as well as pharmaceutical and biomedical fields for their biocompatibility,biodegradability,...As a kind of biopolymer,hydrolysates of fish swim bladder,safer than those of land mammals,are widely used in food,cosmetics as well as pharmaceutical and biomedical fields for their biocompatibility,biodegradability,and weak antigenicity.To enhance hydrolysate production,in this paper,the papain and alcalase hydrolysis processes of larimichthys polyactis swim bladder were optimized with orthogonal experiments.With 89.5%hydrolysate yield,the optimal processing conditions for alcalase were solid-liquid ratio of 1:30,enzyme concentration of 0.7%,and extraction time of 6 h.As for papain,under the optimal processing conditions:solid-liquid ratio of 1:20,enzyme concentration of 0.5%,and extraction time of 8 h,the hydrolysate yield was 65.1%.To obtain higher hydrolysate yields,the ultrasonic pretreatments were implemented before the optimal enzyme hydrolysis processes.With ultrasonic waves of 100 W for 50 min,the hydrolysate yields were increased 2.1%(alcalase)and 4.5%(papain),respectively.The Fourier Transform Infrared(FTIR)spectroscopic analysis revealed that the hydrolysates extracted by papain exist in triple-helical forms.The Ultra-Violet(UV)absorption spectra indicated that the aromatic amino acids in the hydrolysates had strong absorptions in the wavelength range of 240 nm–300 nm.The results of this research demonstrate that the alcalase hydrolysates have better solubility in water and the solution is more stable under ambient temperature.However,the hydrolysates extracted by papain have a gel property and are insoluble in weak acid at room temperature,which is more suitable for applications in feedstock of biomedical.展开更多
The combined effects of drying methods and limited enzymatic hydrolysis on the techno-functional characteristics of rice protein hydrolysates(RH)were investigated.With the increasing hydrolysis degree,the average size...The combined effects of drying methods and limited enzymatic hydrolysis on the techno-functional characteristics of rice protein hydrolysates(RH)were investigated.With the increasing hydrolysis degree,the average size,exposed and total SH content,iron chelating capacity,hydroxyl and DPPH radical scavenging activity increased.Drying methods and enzyme type can alter the conformation of protein.Trypsin-derived spray dried RH exhibited higherα-helix contents while neutrase-derived ones had lowerα-helix contents.The freeze-dried RH owed higher hydroxyl and DPPH scavenging activity than their spray-dried counterparts,which was related to higher sulfhydryl group and hydrophobic amino acids contents.RH derived from trypsin had higher metal chelating capacity than that from neutrase,which was in an agreement with higher amount of peptide<1000 Da.The shifting to lower relaxation time in spray-dried RH reflects lower water absorption capacity and slower water mobility,which are less susceptible to spoilage bacteria.Freeze drying would be a more prevalent technique for fully utilization of RH as bioactive components in the food system.展开更多
基金This research was funded by the Fundamental Research Funds for the Central Universities,Grant No.2572018AB10the Fundamental Research Funds for the Central Universities,Grant No.2572019BB07.
文摘As a kind of biopolymer,hydrolysates of fish swim bladder,safer than those of land mammals,are widely used in food,cosmetics as well as pharmaceutical and biomedical fields for their biocompatibility,biodegradability,and weak antigenicity.To enhance hydrolysate production,in this paper,the papain and alcalase hydrolysis processes of larimichthys polyactis swim bladder were optimized with orthogonal experiments.With 89.5%hydrolysate yield,the optimal processing conditions for alcalase were solid-liquid ratio of 1:30,enzyme concentration of 0.7%,and extraction time of 6 h.As for papain,under the optimal processing conditions:solid-liquid ratio of 1:20,enzyme concentration of 0.5%,and extraction time of 8 h,the hydrolysate yield was 65.1%.To obtain higher hydrolysate yields,the ultrasonic pretreatments were implemented before the optimal enzyme hydrolysis processes.With ultrasonic waves of 100 W for 50 min,the hydrolysate yields were increased 2.1%(alcalase)and 4.5%(papain),respectively.The Fourier Transform Infrared(FTIR)spectroscopic analysis revealed that the hydrolysates extracted by papain exist in triple-helical forms.The Ultra-Violet(UV)absorption spectra indicated that the aromatic amino acids in the hydrolysates had strong absorptions in the wavelength range of 240 nm–300 nm.The results of this research demonstrate that the alcalase hydrolysates have better solubility in water and the solution is more stable under ambient temperature.However,the hydrolysates extracted by papain have a gel property and are insoluble in weak acid at room temperature,which is more suitable for applications in feedstock of biomedical.
基金The authors are very grateful to the financial support of the research project sponsored by the National Natural Science Foundation of China(31860451)the Natural Science Fund for Distinguished Young Scholars of Jiangxi Province(20192BCB23006)the Major Science and Technology Project of Jiangxi Academy of Sciences(2018-YZD1-05).
文摘The combined effects of drying methods and limited enzymatic hydrolysis on the techno-functional characteristics of rice protein hydrolysates(RH)were investigated.With the increasing hydrolysis degree,the average size,exposed and total SH content,iron chelating capacity,hydroxyl and DPPH radical scavenging activity increased.Drying methods and enzyme type can alter the conformation of protein.Trypsin-derived spray dried RH exhibited higherα-helix contents while neutrase-derived ones had lowerα-helix contents.The freeze-dried RH owed higher hydroxyl and DPPH scavenging activity than their spray-dried counterparts,which was related to higher sulfhydryl group and hydrophobic amino acids contents.RH derived from trypsin had higher metal chelating capacity than that from neutrase,which was in an agreement with higher amount of peptide<1000 Da.The shifting to lower relaxation time in spray-dried RH reflects lower water absorption capacity and slower water mobility,which are less susceptible to spoilage bacteria.Freeze drying would be a more prevalent technique for fully utilization of RH as bioactive components in the food system.
