[Objective] To investigate the optimal enzyme for the hydrolysis of corn gluten meal and the optimal hydrolysis conditions for the enzyme. [Method] Nine kinds of enzymes were used to hydrolyze the corn gluten meal, us...[Objective] To investigate the optimal enzyme for the hydrolysis of corn gluten meal and the optimal hydrolysis conditions for the enzyme. [Method] Nine kinds of enzymes were used to hydrolyze the corn gluten meal, using the formaldehyde titration method for the determination of hydrolysis degree, and orthogonal test was used to determine the optimal hydrolysis conditions for double enzymes hydrol- ysis of corn gluten meal. [Result] The optimal pretreatment condition for corn gluten meal is heating at 121 ~C for 30 min. The double enzyme hydrolysis for the pro- treated corn gluten meal using 2709 alkaline protease and flavourzyme showed that the degree of hydrolysis could reach 32.4% with enzyme addition amount of 4%, hy- drolysis time of 4 h at 45℃ and pH=7.0. [Conclusion] This study laid the foundation for the study on the preparation of bioactive peptides such as oligopeptide with high F value and antihypertensive peptides, further improving the corn intensive process- ing industrial chain.展开更多
A total of 400 yeast strains from seawater, sediments, saltern mud, marine fish guts, and marine algae were obtained. The protease activity of the yeast cultures was estimated, after which four strains （HN3.11, Nllb,...A total of 400 yeast strains from seawater, sediments, saltern mud, marine fish guts, and marine algae were obtained. The protease activity of the yeast cultures was estimated, after which four strains （HN3.11, Nllb, YF04C and HN4.9） capable of secreting extracellular alkaline protease were isolated. The isolated strains were identified as Aureobasidium pullulans, Yarrowia lipolytica, lssatchenkia orientalis and Cryptococcus cf. aureus. The optimal pH of the protease activity produced by strains HN3.11, YF04C, and HN4.9 was 9.0, while that of the protease produced by strain N1 lb was 10.0. The optimal temperature for protease activity was 45℃for strains HN3.11, N11b, and YF04C, and 50℃ for strain HN4.9. After digestion of shrimp （Penaeus vannamei） protein and spirulina （Arthospira platens＆） protein with the four crude alkaline proteases, the filtrate from spirulina （Arthrospira platensis） powder digested by the crude alkaline protease of strain HNYl 1 was found to have the highest antioxidant activity （61.4%） and the highest angiotensin I converting enzyme （ACE）-inhibitory activities （68.4%）. The other filtrates had much lower antioxidant activity and ACE-inhibitory activities.展开更多
Focus in nutritional science has turned towards components in, or added to, foods that may possess health beneficial activities beyond the classical nutritional value, namely functional food. Bioactive peptides are ex...Focus in nutritional science has turned towards components in, or added to, foods that may possess health beneficial activities beyond the classical nutritional value, namely functional food. Bioactive peptides are examples of such components. In vitro studies on bioactivities have mainly been executed without concerning subsequent digestion after intake and the aim of this work was hence to investigate how the in vitro antioxidative, antihypertensive and caspase activating activities of peptides are affected by digestion with gastrointestinal （GI） proteases. Five different fish protein hydrolysates were chosen to study the effect of in vitro digestion on bioactivity. The protein concentration decreased in all samples during digestion and the molecular weight distribution of the peptides shifted towards lower values. Thus, in vitro digestion with GI proteases resulted in a further degradation of the peptides obtained by hydrolysis. The antihypertensive effect increased in all samples after digestion with GI proteases whereas the antioxidative capacity decreased. The effect on the caspase activity depended on the proteases used in the preparation of hydrolysates. In conclusion, the caspase activity and antihypertensive activity are maintained during digestion with GI proteases, while the antioxidative capacity seems to be reduced.展开更多
Research on marine bioactive peptides has mainly focused on characterization of peptides in hydrolysates prepared with commercial industrial enzymes and the usefulness of such hydrolysates in health and functional foo...Research on marine bioactive peptides has mainly focused on characterization of peptides in hydrolysates prepared with commercial industrial enzymes and the usefulness of such hydrolysates in health and functional foods. However, a relevant question is whether digestion of fish proteins with gastrointestinal proteases per se generates peptides that also can have health promoting properties and can reduce, e.g., diabetes 2, inflammation and hypertension either in relation to gastrointestinal digestion or as alternative to industrial proteases. The aim of the study was to investigate hydrolysates obtained from in vitro sequential digestion of salmon muscle and skin with gastrointestinal proteases including pepsin, pancreatic and pancreatic ＋ mucosal proteases for their ability to scavenge ABTS^＋ radicals and inhibit activity of angiotensin I-converting enzyme （ACE） and dipeptidyl peptidase 4 （DPP-4）. Furthermore, it was the aim to study the inhibitory mechanism and stability towards ACE and DPP-4 activity. Analysis of〈 10 kDa hydrolysates showed that gastrointestinal proteases generated peptides with clear radical scavenging activity and DPP-4 and ACE inhibiting activity as well. Hydrolysates from pepsin digestion exhibited the lowest ECso values for radical scavenging activity and ACE inhibition, whereas ECso increased in hydrolysates after subsequent digestion with pancreatic and mucosal proteases. Interestingly, ECso values for the DPP-4 inhibition were hardly affected by sequential digestion. Inhibition modes for the muscle hydrolysates were both competitive and non-competitive, but prolonged incubation showed that the inhibitory properties were unstable and therefore they were probably digested as competitive substrates by gastrointestinal proteases.展开更多
文摘[Objective] To investigate the optimal enzyme for the hydrolysis of corn gluten meal and the optimal hydrolysis conditions for the enzyme. [Method] Nine kinds of enzymes were used to hydrolyze the corn gluten meal, using the formaldehyde titration method for the determination of hydrolysis degree, and orthogonal test was used to determine the optimal hydrolysis conditions for double enzymes hydrol- ysis of corn gluten meal. [Result] The optimal pretreatment condition for corn gluten meal is heating at 121 ~C for 30 min. The double enzyme hydrolysis for the pro- treated corn gluten meal using 2709 alkaline protease and flavourzyme showed that the degree of hydrolysis could reach 32.4% with enzyme addition amount of 4%, hy- drolysis time of 4 h at 45℃ and pH=7.0. [Conclusion] This study laid the foundation for the study on the preparation of bioactive peptides such as oligopeptide with high F value and antihypertensive peptides, further improving the corn intensive process- ing industrial chain.
基金Supported by the High Technology Research and Development Program of China (863 Program) (No.2006AA09Z403)the National Science and Technology Infrastructure Program of China (No.2005DKA21209)
文摘A total of 400 yeast strains from seawater, sediments, saltern mud, marine fish guts, and marine algae were obtained. The protease activity of the yeast cultures was estimated, after which four strains （HN3.11, Nllb, YF04C and HN4.9） capable of secreting extracellular alkaline protease were isolated. The isolated strains were identified as Aureobasidium pullulans, Yarrowia lipolytica, lssatchenkia orientalis and Cryptococcus cf. aureus. The optimal pH of the protease activity produced by strains HN3.11, YF04C, and HN4.9 was 9.0, while that of the protease produced by strain N1 lb was 10.0. The optimal temperature for protease activity was 45℃for strains HN3.11, N11b, and YF04C, and 50℃ for strain HN4.9. After digestion of shrimp （Penaeus vannamei） protein and spirulina （Arthospira platens＆） protein with the four crude alkaline proteases, the filtrate from spirulina （Arthrospira platensis） powder digested by the crude alkaline protease of strain HNYl 1 was found to have the highest antioxidant activity （61.4%） and the highest angiotensin I converting enzyme （ACE）-inhibitory activities （68.4%）. The other filtrates had much lower antioxidant activity and ACE-inhibitory activities.
文摘Focus in nutritional science has turned towards components in, or added to, foods that may possess health beneficial activities beyond the classical nutritional value, namely functional food. Bioactive peptides are examples of such components. In vitro studies on bioactivities have mainly been executed without concerning subsequent digestion after intake and the aim of this work was hence to investigate how the in vitro antioxidative, antihypertensive and caspase activating activities of peptides are affected by digestion with gastrointestinal （GI） proteases. Five different fish protein hydrolysates were chosen to study the effect of in vitro digestion on bioactivity. The protein concentration decreased in all samples during digestion and the molecular weight distribution of the peptides shifted towards lower values. Thus, in vitro digestion with GI proteases resulted in a further degradation of the peptides obtained by hydrolysis. The antihypertensive effect increased in all samples after digestion with GI proteases whereas the antioxidative capacity decreased. The effect on the caspase activity depended on the proteases used in the preparation of hydrolysates. In conclusion, the caspase activity and antihypertensive activity are maintained during digestion with GI proteases, while the antioxidative capacity seems to be reduced.
文摘Research on marine bioactive peptides has mainly focused on characterization of peptides in hydrolysates prepared with commercial industrial enzymes and the usefulness of such hydrolysates in health and functional foods. However, a relevant question is whether digestion of fish proteins with gastrointestinal proteases per se generates peptides that also can have health promoting properties and can reduce, e.g., diabetes 2, inflammation and hypertension either in relation to gastrointestinal digestion or as alternative to industrial proteases. The aim of the study was to investigate hydrolysates obtained from in vitro sequential digestion of salmon muscle and skin with gastrointestinal proteases including pepsin, pancreatic and pancreatic ＋ mucosal proteases for their ability to scavenge ABTS^＋ radicals and inhibit activity of angiotensin I-converting enzyme （ACE） and dipeptidyl peptidase 4 （DPP-4）. Furthermore, it was the aim to study the inhibitory mechanism and stability towards ACE and DPP-4 activity. Analysis of〈 10 kDa hydrolysates showed that gastrointestinal proteases generated peptides with clear radical scavenging activity and DPP-4 and ACE inhibiting activity as well. Hydrolysates from pepsin digestion exhibited the lowest ECso values for radical scavenging activity and ACE inhibition, whereas ECso increased in hydrolysates after subsequent digestion with pancreatic and mucosal proteases. Interestingly, ECso values for the DPP-4 inhibition were hardly affected by sequential digestion. Inhibition modes for the muscle hydrolysates were both competitive and non-competitive, but prolonged incubation showed that the inhibitory properties were unstable and therefore they were probably digested as competitive substrates by gastrointestinal proteases.
