scholarly journals Effect of Temperature, pH, Enzyme to Substrate Ratio, Substrate Concentration and Time on the Antioxidative Activity of Hydrolysates from Goat Milk Casein by Alcalase

2016 ◽  
Vol 20 (2) ◽  
pp. 29-38 ◽  
Author(s):  
Guowei Shu ◽  
Bowen Zhang ◽  
Qian Zhang ◽  
Hongchang Wan ◽  
Hong Li

Abstract The effect of hydrolysis temperature (45, 50, 55, 60 and 65°C), pH (7.0, 7.5, 8.0, 8.5 and 9.0), enzyme to substrate (E/S) ratio (1.0, 1.5, 2.0, 2.5 and 3.0%), substrate concentration (2, 3, 4, 5 and 6%) and hydrolysis time (30-240min) on antioxidant peptides hydrolysated from goat’s milk casein by Alcalase was investigated using single factor experiment. In order to obtain high DPPH radical-scavenging activity, metal-chelating activity and superoxide radical scavenging activity, the optimal conditions were hydrolysis time of 150 min, temperature of 50°C, pH 8.0, E/S ratio of 2.0% and substrate concentration of 4.0%. The hydrolysis time, hydrolysis temperature, pH, E/S ratio and substrate concentration had a significant influence on degree of hydrolysis, metal-chelating activity, DPPH and superoxide radical scavenging activity on casein hydrolysate of goat milk by Alcalase, the results were beneficial for further provide theoretical basis for production of antioxidant peptides.

2017 ◽  
Vol 21 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Guowei Shu ◽  
Zhuo Wang ◽  
Li Chen ◽  
Qian Zhang ◽  
Ni Xin

AbstractAntioxidant peptides can inhibit lipid peroxidation and scavenging free radicals, maintain the balance of free radicals, and against a variety of diseases. Response surface methodology was used to optimize process conditions for producing antioxidative peptides from goat’s milk casein hydrolysate with Alcalase. The results suggested that the optimal process parameters were: temperature at 62.5°C, pH 8.9, E/S ration at 2.5%, substrate concentration at 4.4% and hydrolysis time was 173min). Metal-chelating effect, superoxide anion radical scavenging activity and 1, 1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity were shown to be 87.21±0.88%, 49.18±1.42% and 69.07±1.26% respectively under the optimal condition. The actual and predicated value were closely which indicated the optimized data fit well to model and the optimized parameters are reliable.


2013 ◽  
Vol 80 (3) ◽  
pp. 367-373 ◽  
Author(s):  
Qiu-Xiang Zhang ◽  
Hui Wu ◽  
Yu-Fang Ling ◽  
Rong-Rong Lu

To isolate and identify antioxidant peptides from enzymatically hydrolysed whey protein, whey protein isolate was hydrolysed by different protease (trypsin, pepsin, alcalase 2·4L, promatex, flavourzyme, protease N). The hydrolysate generated by alcalase 2·4L had the highest antioxidant activities on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, superoxide radicals and in a linoleic acid peroxidation system induced by Fe2+. The IC50 values of DPPH and superoxide radical scavenging activities of the hydrolysate decreased significantly (6·89 and 38·88%, respectively) after treatment with macroporous adsorption resin. Seven different peptides showing strong antioxidant activities were isolated from the hydrolysate using consecutive chromatographic methods including gel filtration chromatography and high-performance liquid chromatography. The molecular mass and amino acids sequences of the purified peptides were determined using a Quadrupole time-of-flight mass spectrometer (Q-TOF MS). One of the antioxidative peptides, Trp–Tyr–Ser–Leu, displayed the highest DPPH radical scavenging activity (IC50=273·63 μm) and superoxide radical scavenging activity (IC50=558·42 μm). These results suggest that hydrolysates from whey proteins are good potential source of natural antioxidants.


2015 ◽  
Vol 19 (2) ◽  
pp. 65-74 ◽  
Author(s):  
Guowei Shu ◽  
Qian Zhang ◽  
He Chen ◽  
Hongchang Wan ◽  
Hong Li

Abstract Oxidation was related to the pathogenesis of human diseases. Adequate intake of antioxidant activity of food can reduce the levels of free radicals, prevent lipid peroxidation, and help the body against diseases. In the paper, casein from goat milk was hydrolyzed by five commercial proteases, namely, Alcalase, flavourzyme, papain, proteinase K and trypsin. The antioxidant activities of casein hydrolysates were assessed by evaluating hydrolysis degree, DPPH radical-scavenging activity, metal-chelating activity and superoxide radical scavenging activity. The results showed as follows: the DH of proteinase K, Alcalase, and trypsin were higher significantly than those of papain and flavourzyme. The Fe2+-chelation activity and superoxide radical scavenging activity of casein hydrolysates from goat milk by Alcalase was higher than the others, the DPPH scavenging activities of casein hydrolysates by Alcalase and papain was higher than the others and the DPPH scavenging activities by Alcalase and papain had no significant diffierence (p<0.05), so the optimal proteinase for hydrolysis casein from goat milk to produce antioxidant peptide was Alcalase.


2011 ◽  
Vol 63 (3) ◽  
pp. 717-721
Author(s):  
Fan Yang ◽  
Zhiwei Yang ◽  
Jianbo Xiao

A preparation of crude polysaccharides (TPS) was isolated from Camellia sinensis by precipitation and ultrafiltration. TPS1, TPS2, and TPS3 had molecular weights of 240, 21.4, and 2.46 kDa, respectively. The radical scavenging activities of TPS were evaluated by DPPH free radical, hydroxyl radical and superoxide radical scavenging. These results revealed that TPS exhibited strong radical scavenging activity in a concentration-dependent manner. TPS3 with lowest molecular weight showed a higher radical scavenging activity.


2020 ◽  
Vol 8 (10) ◽  
pp. 1461 ◽  
Author(s):  
Naif Abdullah Al-Dhabi ◽  
Mariadhas Valan Arasu ◽  
Ponnuswamy Vijayaraghavan ◽  
Galal Ali Esmail ◽  
Veeramuthu Duraipandiyan ◽  
...  

In recent years, studies have focused on the therapeutic properties of probiotics to eliminate pathogenic microorganisms associated with various diseases. Lactobacilli are important probiotics groups that have been found to possess many health-promoting activities. This study was carried out to isolate LactobacillusreuteriLR12 and L. lactisLL10 from pineapple puree. The invitro analysis to evaluate probiotic characteristics of the isolated bacteria included survival in bile and acid tolerance. The cell-free supernatant of L. reuteri LR12 was effective against various pathogenic bacteria and fungi compared with L. lactisLL10. These two bacterial strains have strong anti-biofilm activity (100%) against Enterococcus faecalis, Staphylococcus aureus, and Bacillus cereus. The bacterial strains exhibited adhesion properties to HT-29 cells (human colorectal adenocarcinoma). These bacteria showed DPPH- (2,2-diphenyl-1-picryl-hydrazyl-hydrate) free radical scavenging activity, scavenging of hydroxyl radical activity, superoxide radical scavenging activity, and reducing power activity in the range of 72% ± 3%to 89.3% ± 1.7%, 64% ± 2.7%to 66.8% ± 1.5%, 59.8% ± 4.1% to 63.8% ± 2.1%, and 60.4% ± 1.8%to 66.1% ± 3.3%, respectively. Pineapple puree was used as the starter culture with milk for 2 days for yogurt preparation. Pineapple puree increased flavor and showed the physicochemical properties of yogurt. The finding of the sensory evaluation revealed no significant change compared with the control, except the appearance of yogurt. These findings show that Lactobacilli and pineapple puree have potential use in various probiotic preparations for the fermentation industry.


2019 ◽  
Vol 86 (3) ◽  
pp. 361-367 ◽  
Author(s):  
Evangelia Zoidou ◽  
Sofia Theodorou ◽  
Ekaterini Moschopoulou ◽  
Lambros Sakkas ◽  
Georgios Theodorou ◽  
...  

AbstractThis research paper addresses the hypothesis that the fortification of goat milk base with whey protein concentrate (WPC) could affect both the textural and the biofunctional properties of set-style yoghurt. The effect of fortification of goat milk base with two different WPCs on thermophilic bacteria counts, proteolysis, physical and biofunctional properties of set-style yoghurts was studied at specific sampling points throughout a 4-week storage period. Fortification and storage did not influence thermophilic counts. Physical properties were affected significantly (P < 0.05) by the composition of the protein and the mineral fraction of the WPC but not by the storage. ACE-inhibitory activity was moderate in accordance to low lactobacilli counts and lack of proteolysis. DPPH-radical scavenging activity, Fe2+-chelating activity and superoxide scavenging activity were high. At 28 d an anti-inflammatory effect was observed, which was not affected by WPC addition.


Foods ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 34 ◽  
Author(s):  
Bin Jiang ◽  
Jiaxin Na ◽  
Lele Wang ◽  
Dongmei Li ◽  
Chunhong Liu ◽  
...  

At present, peptides are separated by molecular exclusion chromatography and liquid chromatography. A separation method is needed in any case, which can be scaled up for industrial scale. In this study, aqueous two-phase extraction (ATPE) and aqueous two-phase flotation (ATPF) were applied to separate and enrich antioxidant peptides from trypsin hydrolysates of whey protein isolates (WPI). The best experimental conditions were investigated, and the results were evaluated using the 2,2′-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) free radical scavenging activity of the peptides-per-unit concentration and the recovery rate (Y) of peptides in the top phase of both ATPE and ATPF. Under optimal conditions, the Y and ABTS free radical scavenging activity per unit concentration in top phase of ATPE could reach 38.75% and 12.94%, respectively, and in ATPF could reach 11.71% and 29.18%, respectively. The purified peptides were characterized by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and reversed-phase high-performance liquid chromatography (RP-HPLC). PeptideCutter and PeptideMass were applied to analyze and calculate the peptide sequencing. KILDKVGINYWLAHK, VGINYWLAHKALCSEK, and TPEVDDEALEKFDKALK sequences having antioxidant activity were detected in the top phase of ATPE, and VGINYWLAHKALCSEK, KILLDKVGINYWLAHK, ILLDKVGINYWLAHK, IIAEKTKIPAVFK, KIIAEKTKIPAVFK, and VYVEELKPTPEGDLEILLQK sequences having antioxidant activity were detected in the top phase of ATPF. In conclusion, antioxidant peptides were successfully separated from the WPI hydrolysate by ATPE and ATPF; compared with ATPE, ATPF has superior specificity in separating antioxidant peptides.


Author(s):  
S. SUJATHA ◽  
T. SEKAR

Objective: In the present study, antioxidant activity in the leaf of the pet-ether, chloroform, acetone and methanolic extracts from Litsea laevigata Gamble. Leaf was investigated by employing established in vitro studies. L. laevigata belongs to the Lauraceae family. Methods: The capability of the plant extract to act as hydrogen/electrons donor or scavenger of radicals were determined by in vitro antioxidant assays using 2,2-diphenyl-2-picrylhydrazyl free radical (DPPH.) scavenging, reducing power assay, superoxide radical (O2*-) scavenging activity, phosphomolybdenum assay, FRAP, ABT and metal chelating activity were performed to know the antioxidant potency of the plant extract of leaves of L. laevigata. Results: Results are evaluated higher in leaf extract of L. laevigata recorded total phenol, total flavonoid, and tannin. The present state of work was designed to evaluate the phytochemical, antioxidant in the plant leaf extracts of L. laevigata. The plant L. laevigata methanolic extract of leaf showed greater IC50 antioxidant activity of DPPH assay (5.264 µg/ml) and compare to other extract, higher phosphomolybdenum reduction (164.36 mg/g), better Reducing power activity leaf in methanol (0.711%), higher ferric reducing power (4060.66MmolFe(II)E/mg), and higher in superoxide radical scavenging activity in (78.12 mg/ml). However, the better metal chelating ability was shown by the water extracts of the leaf (5.145 EDTAE/100g) compared to other solvent extracts. Conclusion: The result indicates the total phenol and antioxidant activity potential of L. laevigata.


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