Determination of the degree of hydrolysis of food protein hydrolysates by trinitrobenzenesulfonic acid

1979 ◽  
Vol 27 (6) ◽  
pp. 1256-1262 ◽  
Author(s):  
Jens Adler-Nissen
1980 ◽  
Vol 45 (4) ◽  
pp. 1099-1108 ◽  
Author(s):  
Mikuláš Chavko ◽  
Michal Bartík ◽  
Evžen Kasafírek

A polarographic study of the hydrolysis of [8-lysine]vasopressin and some hormonogens of the vasopressin series with the blood serum of women in the last week of pregnancy was studied. The dependence of hydrolysis on pH (pH optimum: 7.4-7.50, substrate concentration (Km 1.2 . 10-5M), pH stability and thermal stability were determined. The rate of hydrolysis of individual vasopressin analogues decreases in the order: [8-lysine]vasopressin > Nα-glycyl-prolyl[8-lysine]-vasopressin > Nα-leucyl-[8-lysine]vasopressin > Nα-alanyl-[8-lysine]vasopressin > Nα-phenyl alanyl-[8-lysine]vasopressin > Nα-diglycyl-[8-lysine]vasopressin > Nα-prolyl-[8-lysine]vasopressin > Nα-triglycyl-[8-lysine]vasopressin > Nα-sarcosyl-glycyl-[8-lysine]vasopressin. The degree of hydrolysis gradually increases to a multiple with the length of the pregnancy in consequence of the presence of oxytocine. However, vasopressin is also hydrolysed to a small extent with the enzymes from the blood sera of non-pregnant women. Under similar analytical conditions oxytocin was not hydrolysed with the sera of non-pregnant women and therefore oxytocin is a more suitable substrate than vasopressin for polarographic determination of serum oxytocinase.


2011 ◽  
Vol 20 (No. 1) ◽  
pp. 7-14 ◽  
Author(s):  
M. Hrčková ◽  
M. Rusňáková ◽  
J. Zemanovič

Commercial defatted soy flour (DSF) was dispersed in distilled water at pH 7 to prepare 5% aqueous dispersion. Soy protein hydrolysates (SPH) were obtained by enzymatic hydrolysis of the DSF using three different proteases (Flavourzyme 1000 L, No-vozym FM 2.0 L and Alcalase 2.4 L FG). The highest degree of hydrolysis (DH 39.5) was observed in the presence of protease Flavourzyme. SPH were used for measuring functional properties (foaming stability, gelation). Treatment with Flavourzyme improved foaming of proteins of DSF. Foaming stability was low in the presence of Novozym. Proteases treated DSF showed good gelation properties, mainly in the case of treatment with Flavourzyme. SDS-PAGE analysis showed that after enzyme ad-dition to the 5% aqueous dispersion of DSF each enzyme degraded both b-conglycinin and glycinin. In general, the basic polypeptide from glycinin showed the highest resistance to proteolytic activity. The most abundant free amino acids in the hydrolysates were histidine (30%), leucine (24%) and tyrosine (19%) in the case of the treatment with proteases Alcalase and Novozym, and arginine (22.1%), leucine (10.6%) and phenylalanine (12.9%) in the case of the treatment with Flavourzyme.  


2014 ◽  
Vol 707 ◽  
pp. 149-153 ◽  
Author(s):  
Xiao Hu ◽  
Xian Qing Yang ◽  
Lai Hao Li ◽  
Yan Yan Wu ◽  
Wan Ling Lin ◽  
...  

Microalgae protein hydrolysates (MPH) were obtained by enzymatic hydrolysis of defatted microalgae meal using neutral protease. The protein recovery, degree of hydrolysis, and the antioxidant activities of the hydrolysates were investigated. The results demonstrated that hydrolysates prepared by neutral protease at 50 °C for 4 h exhibited the strongest antioxidant activity. Under these conditions, the 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical scavenging activity and the reducing power of the hydrolysates were 68.3%, 50.8% and 1.303, respectively.


2012 ◽  
Vol 554-556 ◽  
pp. 1327-1331
Author(s):  
Li Jun Zhang ◽  
Qian Cheng Zhao ◽  
Bing Bing Wang ◽  
Xue Wan ◽  
Zhi Bo Li ◽  
...  

Protein hydrolysates from Tuna frame (TFPH) and Pollock frame (PFPH) were prepared by papain, respectively.The yield, the basic composition content, the antioxidant activity and functional properties (solubility, emulsifying and foaming ability) and the degree of hydrolysis of the protein hydrolysates were evaluated. Results suggest that solubility, antioxidant activity of protein hydrolysate from Pollock frame are better than that of tuna frame, but the yield is lower than that of tuna frame.


10.5219/1264 ◽  
2020 ◽  
Vol 14 ◽  
pp. 379-384
Author(s):  
Ace Baehaki ◽  
Indah Widiastuti ◽  
Citra Nainggolan ◽  
Nuni Gofar

The purpose of this research was to study the antioxidants activities of peptides from skin fish of snakehead (Channa striata), using hydrolysis of protease TP2 isolate from swamp plant silage. This research 5 treatments hydrolysis time (0, 30, 60, 90, 120 min, respectively), with two replicates, which included several stages of preparation and pre-treatment of the snakehead fish skin production of protease enzymes which were isolated from swamp water, preparation of protein hydrolysates, measurement of hydrolysis degrees, analysis of peptides content and analysis of the antioxidant activity. Results showed that the treatment had given a significant effect on the 5% level of the degree of hydrolysis production (13.98% ”“ 27.08%), with peptides content of 2.73% ”“ 3.78% and antioxidant activity (10.75% ”“ 20.7%). The results of the degree of hydrolysis indicate that the longer the hydrolysis time, the percent degree of hydrolysis will increase. Peptide content and antioxidant activity were increased with increasing hydrolysis time.


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