• Food Science and Biotechnology
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• v.15 no.1
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• pp.128-132
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• 2006

This study was undertaken to investigate the effect of peptic and chymotryptic hydrolyses of 7S globulin, the major allergen of soybean protein, on its allergenicity, as measured by enzyme linked immunosorbent assay (ELISA), and to identify the allergenic hydrolyzed fragments of 7S globulin using SDS-PAGE. When 7S globulin was hydrolyzed by pepsin, the allergenicity was reduced by over 50%. However, the allergenicity of 7S globulin reduced by peptic hydrolysis was recovered in the sera from 5 out of 10 patients following sequential chymotryptic hydrolysis. Two fragments, with molecular weights 20-25 and 13-16 kDa, among the hydrolysate of 7S globulin by sequential pepsin and chymotrypsin showed reactivity with sera from 10 soybean-allergenic patients. As a result of the theoretical hydrolyses of ${\beta}$-conglycinin, which is a major protein of 7S globulin, it is suggested that the 20-25 kDa fragments were the fragments of the ${\alpha}$-subunit of ${\beta}$'-conglycinin and that the 10-16 kDa fragments were from the ${\alpha}$'-subunit.

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.3
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• pp.233-241
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• 1988

In order to develop a new type of food source for the effective utilization of fish protein, plastein reaction was applied to improve the functional properties of sardine protein. Conditions necessary for optimal plastein productivity from sardine protein using pepsin, ${\alpha}-chymotrypsin$, protease(from Aspergillus saitoi) and papain were established. Sardine protein concentrate was hydrolyzed with pepsin yielding an approximate degree of hydrolysis of 78.4%. Enzyme induced plastein was optimized at : pH 4 for pepsin, pH 7 for ${\alpha}-chymotrypsin$, pH 5 for pretense and pH 6 for papain : Substrate concentrate 40% for pepsin and ${\alpha}-chymotrypsin$, 50% for pretense and papain : the time of incubation, 24hr : enzyme/substrate ratio, 1 : 100(w/v) incubation temperature, $50^{\circ}C$.

• Food Science of Animal Resources
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• v.33 no.4
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• pp.493-500
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• 2013

Gelatin is a collagen-containing thermohydrolytic substance commonly incorporated in cosmetic and pharmaceutical products. This study investigated the antioxidant activity of gelatin by using different reagents, such as 2,2-azinobis-(3-ethylbenzothiazoline- 6-sulfonic acid) (ABTS), 2,2-di (4-tert-octylphenyl)-1-picrylhydrazyl (DPPH), and oxygen radical absorbance capacity-fluorescein (ORAC-FL) in a porcine gelatin hydrolysate obtained using gastrointestinal enzymes. Electrophoretic analysis of the gelatin hydrolysis products showed extensive degradation by pepsin and pancreatin, resulting in an increase in the peptide concentration (12.1 mg/mL). Antioxidant activity, as measured by ABTS, exhibited the highest values after 48-h incubation with pancreatin treatment after pepsin digestion. Similar effects were observed at 48 h incubation, that is, 61.5% for the DPPH assay and 69.3% for the ABTS assay. However, the gallic acid equivalent (GE) at 48 h was $87.8{\mu}M$, whereas $14.5{\mu}M$ GE was obtained using the ABTS and DPPH assays, indicating about sixfold increase. In the ORACFL assay, antioxidant activity corresponding to $45.7{\mu}M$ of trolox equivalent was found in the gelatin hydrolysate after 24 h hydrolysis with pancreatin treatment after pepsin digestion, whereas this activity decreased at 48 h. These antioxidant assay results showed that digestion of gelatin by gastrointestinal enzymes prevents oxidative damage.

• Journal of the Korean Society of Food Science and Nutrition
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• v.4 no.1
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• pp.49-53
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• 1975

The effect of natural condiments on peptic hydrolysis of casein in vitro has been studied, peptic activity was determined by the colorimetric method using folin reagent. The obstructive compounds on colorimetry from hydrolyzates of casein were separated by gel filteration method using sephadex G-10 column and 0.05M NaCl. Zinger and red pepper $(0.1{\sim}1.0%)$ were found to have slightly supressing effect for protein digestive action of pepsin. But garlic, green onion and onion acted as synergist for protein digertive action of pepsin.

• Microbiology and Biotechnology Letters
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• v.18 no.5
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• pp.496-500
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• 1990

When pepsin was used at a concentration of 8 mglml for hydrolysis of 0.02% casein, inhibitory activity of this inhibitor was proportional to a inhibitor concentration of 20 ${\mu}g$/ml, and fifty percent inhibition ($IC_{50}$) was observed to be 15 ${\mu}g$/ml. The inhibitor was pH-stable at pH range of 5-9 at $100^{\circ}C$ for 10 minutes and thermo-stable at pH 7.0 at $100^{\circ}C$ to give 100% activity for 20 minutes. The formation of pepsin-inhibitor complex was confirmed by sephadex 6-25 gel filtration and type of inhibition was determined as non-competitive inhibition by Lineweaver-Burk plot. The inhibitor strongly inhibited acid proteases such as pepsin and renin, and it was soluble in methanol very well. On TLC analysis of silicagel 60 using various sohent systems, the inhibitor gave a single spot at Rf range 0.4-0.6. From the result of IR spectrum and color reaction (Rydon-Smith, Biuret), this inhibitor was considered as peptide substance. Melting point and elemental contents were 220-$230^{\circ}C$, and C 50.61%-H 8.02%-N 9.34% (found), respectively.

• Food Science of Animal Resources
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• v.30 no.6
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• pp.923-929
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• 2010

Colostral whey prepared from colostrum (pooled from first six post-partum milkings) was heated for 10 min at $100^{\circ}C$ Heated colostral whey was incubated with 1% enzymes (protein equivalent basis) for 15, 30, 60, 90, and 120 min at $50^{\circ}C$. Papain, pepsin, trypsin, and alcalase produced different degrees of hydrolysis (DH), 10.66%, 12.42%, 10.83%, and 25.31%, respectively, at an incubation time of 120 min. The SDS-PAGE reveals that significant amounts of bovine serum albumin (BSA), ${\beta}$-lactoglobulin (${\beta}$-LG), and ${\alpha}$-lactalbumin (${\alpha}$-LA) survived papain digestion. In contrast, pepsin completely removed BSA but not ${\beta}$-LG present in heated colostral whey. Alcalase completely eliminated BSA, ${\beta}$-LG, and ${\alpha}$-LA. This differential hydrolysis was confirmed by reversed-phase HPLC analysis. Using ion-exchange chromatography, fraction-1 (F-1) was obtained from alcalase hydrolysate at a NaCl gradient concentration of 0.25 M. Reversed-phase HPLC chromatograms of alcalase F-1 showed numerous small peaks, which probably indicate that a variety of new peptides were produced. Iron content of alcalase F-1 was 28.94 ppm, which was the highest among all enzyme fractions, whereas iron content of colostral whey was 36.56 ppm. Main amino acids contained in alcalase F-1 were Thr (15.45%), Glu (14.12%), and Ser (10.39%). Therefore, alcalase can be used to generate good iron-binding peptides in heated colostral whey, and the resulting iron-binding peptides could be suitable as a value-added food ingredient for food supplements.

• Membrane Journal
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• v.10 no.2
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• pp.83-91
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• 2000

In order to improve functional properties, enzymatic hydrolysis of FPC (fish protein concentration) was achieved in ultrafiltration membrane reactor (MWCO 5,000). First, insoluble FPC was hydrolyzed by pepsin in batch reactor to decrease the fouling in ultrafiltration membrane reactor, and second hydrolysis was achieved by pronase E in ultrafiltration membrane reactor The optimum operating conditions in batch reactor using pepsin were at temperature 45$^{\circ}C$, pH 2.0 and the ratio of substrate to pepsin, 150 (w/w) After operating for 5hrs under optimum conditions, 89％ of total amount of initial FPC was hydrolyzed. The rate constants, $K_{m}$ and V$_{max}$, were 1.25％ and 0.89 mg/$m\ell$/min, respectively, and substrate inhibition was occured above 1.5％. The ultrafiltration membrane reactor was operated with recycling rate of 474 $m\ell$/min and transmembrane pressure of 15 psi. The permeate flux was increased by temperature, transmembrane pressure, but the permeate flux was fixed by pH. The optimum ratio of substrate to pronase E was 200(w/w) and the productivity of ultrafiltration membarane reactor was 702 mg/mg -enzyme, that of batch reactor was 51mg/mg-enzyme. Molecular weight distributions tot first and second hydrolysates were from 2,500 Da to 20,000 Da and from 700 Da to 10,000 Da, respectivelyly.

• Food Science of Animal Resources
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• v.34 no.1
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• pp.14-19
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• 2014

This study investigated the effects of protease treatments (trypsin, chymotrypsin, and pepsin) under various pressure levels (0.1-300 MPa) for the characteristics of porcine placenta hydrolysates. According to gel electrophoretic patterns, the trypsin showed the best placental hydrolyzing activity followed by chymotrypsin, regardless of the pressure levels. In particular, the peptide bands of tryptic-digested hydrolysate were not shown regardless of applied pressure levels. The peptide bands of hydrolysate treated chymotrypsin showed gradual decreases in molecular weights ($M_w$) with increasing pressure levels. However, the pepsin did not show any evidences of placental hydrolysis even though the pressure levels were increased to 300 MPa. The gel permeation chromatography (GPC) profiles showed that the trypsin and pepsin had better placental hydrolyzing activities under high pressure (particularly at 200 MPa), with lower $M_w$ distributions of the hydrolysates. Pepsin also tend to lower the $M_w$ of peptides, while the major bands of hydrolysates being treated at 300 MPa were observed at more than 7,000 Da. There were some differences in amino acid compositions of the hydrolysates, nevertheless, the peptides were mainly composed of glycine (Gly), alanine (Ala), hydroxyproline (Hyp) and proline (Pro). Consequently, the results indicate that high pressure could enhance the placental hydrolyzing activities of the selected proteases and the optimum pressure levels at which the maximum protease activity is around 200 MPa.

• Food Science of Animal Resources
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• v.40 no.6
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• pp.1033-1043
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• 2020

This study investigated the impacts of gelatin hydrolysate addition on the technological properties and lipid oxidation stability of cooked sausage. Gelatin hydrolysate was prepared from pork and duck skin gelatin, through stepwise hydrolysis using collagenase and pepsin. The cooked sausages were formulated without gelatin (control) or with 1% pork skin gelatin, 1% duck skin gelatin, 1% pork skin gelatin hydrolysate, and 1% duck skin gelatin hydrolysate. The pH, color characteristics, protein solubility, cooking loss, and textural properties of cooked sausages were evaluated, and the 2-thiobarbituric acid reactive substances (TBARS) value was measured weekly to determine lipid oxidation stability during 4 wk of refrigerated storage. Enzymatic hydrolysis of gelatin decreased protein content and CIE L* but increased redness and yellowness (p<0.05). When 1% gelatin or gelatin hydrolysate was incorporated in cooked sausage, however, little to no impacts on pH value, moisture content, protein content, color characteristics, protein solubility, and cooking loss were found (p>0.05). The addition of 1% duck skin gelatin hydrolysate increased the cohesiveness and chewiness of cooked sausages. The inclusion of 1% duck skin gelatin accelerated lipid oxidation of cooked sausages during refrigerated storage (p<0.05), whereas duck skin gelatin hydrolysate caused a lower TBARS value in cooked sausage compared to duck skin gelatin. The results show comparable effects of gelatin and gelatin hydrolysate addition on the technological properties of cooked sausages; however, the oxidative stability of raw materials for gelatin extraction should be evaluated clearly in further studies.

• Korean Journal of Food Science and Technology
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• v.26 no.1
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• pp.74-80
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• 1994

As a preliminary study about the reduction of the antigenicity of whey protein isolate(WPI) by treatment of chymotrypsin, trypsin, pancreatin, and protease from Aspergillus oryzae, the properties and antigenicities of whey protein hydrolysates(WPH) were investigated. When degrees of hydrolysis (DH) were measured by use of trinitrobenzensulfonic acid(TNBS), the DH of the WPH treated by pancreatin or protease from Aspergillus oryzae$(5.05{\sim}11.47)$ were much higher than those of the tryptic or chymotryptic WPH$(15.67{\sim}20.20)$. And the pretreatments of heat$(75^{\circ}C)$, 20 min and/or pepsin resulted in higher DH of WPH, generally. When the molecular distributions of the WPH were determined by high performance size exclusion chromatography(HPSEC), the ratios of polypeptides with molecular weight more than 10kDa ranged from 12% to 36%, and the average molecular weights and the average peptide lengths of the WPH were $4,252{\sim}9,132$ dalton and $38{\sim}83$ amino acids, respectively. And there was no bitter taste in all of the WPH. Results of SDS-PAGE showed that most of intact native proteins were eliminated by the enzymatic hydrolysis but there were a few bands of peptides larger than 14.2 kDa in some WPH. When antigenicity was assayed by competitive inhibition enzyme-linked immunosorbent assay(cELISA), monovalent antigenicity of WPH to rabbit anti-WPI antiserum were lowered to $10^{-1.7}-10^{-4.9}$ times and less by the enzymatic hydrolysis. And the pretreatments of heat and pepsin resulted in the lowest antigenicicy within a group of enzymatic hydrolysis, especially in case of the pancreatic hydrolysate(PDP) whose antigenicity was found almost to be removed.