• Journal of the East Asian Society of Dietary Life
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• v.19 no.1
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• pp.45-51
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• 2009

In this study, food protein hydrolysates were prepared from six types of food protein: purified meat protein, whole egg protein, casein, isolated soy protein, concentrated rice protein, and gluten. Food proteins were hydrolyzed with pepsin and ethanol (80%)-soluble fractions of pepsin hydrolysates were employed for analysis. The products were colorless and odorless powders with low fat content and good solubility. The MW (molecular weight) of the protein hydrolysates was confirmed to be $200{\sim}1,800$ via gel filtration. Free amino acid contents accounted for less than 5% of the samples. The results of our amino acid analysis revealed that all food protein hydrolysates preserved their original amino acid compositions and nutritional values of their source proteins with highly pure oligopeptide mixtures. These results show that the food protein hydrolysates prepared in these investigations should prove excellent dietary nitrogen sources for a variety of applications.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.5
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• pp.712-718
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• 2004

This study was carried out to separate the calcium-binding protein derived from enzymatic hydrolysates of cheese whey protein. CWPs (cheese whey protein) heated for 10 min at $100^{\circ}C$ were hydrolyzed by trypsin, papain W-40, protease S, neutrase 1.5 and pepsin, and then properties of hydrolysates, separation of calcium-binding protein and analysis of calcium-binding ability were investigated. The DH (degree of hydrolysis) and NPN (non protein nitrogen) of heated-CWP hydrolysates by commercial enzymes were higher in trypsin than those of other commercial enzymes. In the result of SDS-PAGE (sodium dodecyl sulphate polyacrylamide gel electrophoresis), $\beta$-LG and $\alpha$-LA in trypsin hydrolysates were almost eliminated and the molecular weight of peptides derived from trypsin hydrolysates were smaller than 7 kDa. In the RP-HPLC (reverse phase HPLC) analysis, $\alpha$-LA was mostly eliminated, but $\beta$-LG was not affected by heat treatment and the RP-HPLC patterns of trypsin hydrolysates were similar to those of SDS-PAGE. In ion exchange chromatography, trypsin hydrolysates were shown to peak from 0.25 M NaCl and 0.5 M NaCl, and calcium-binding ability is associated with the large peak, which was eluted at a 0.25 M NaCl gradient concentration. Based on the results of this experiment, heated-CWP hydrolysates by trypsin were shown to have calcium-binding ability.

• Preventive Nutrition and Food Science
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• v.15 no.4
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• pp.282-286
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• 2010

To isolate a calcium-binding peptide from chlorella protein hydrolysates, chlorella protein was extracted and hydrolyzed using Flavourzyme, a commercial protease. The degree of hydrolysis and calcium-binding capacity were determined using trinitrobenzenesulfonic acid and orthophenanthroline methods, respectively. The enzymatic hydrolysis of chlorella protein for 6 hr was sufficient for the preparation of chlorella protein hydrolysates. The hydrolysates of chlorella protein were then ultra-filtered under 5 kDa as molecular weight. The membrane-filtered solution was fractionated using ion exchange, reverse phase, normal phase chromatography, and fast protein liquid chromatography to identify a calcium-binding peptide. The purified calcium-binding peptide had a calcium binding activity of 0.166 mM and was determined to be 700.48 Da as molecular weight, and partially identified as a peptide containing Asn-Ser-Gly-Cys based on liquid chromatography/electrospray ionization tandem mass spectrum.

• Food Science and Industry
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• v.51 no.4
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• pp.313-324
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• 2018

As excessive intake of salt is regarded as a reason for health problems, the tendency of people to attempt to reduce intake of salt in their everyday lives is on the rise. In Korea, where many people have a higher intake of salt compared to those in other countries, there have been diverse efforts to improve on this eating habit. Protein hydrolysates are chemically, physically hydrolyzed protein that have been widely utilized as a material for not only regular food but health functional food due to have diverse biological effects such as anti-oxidation, anti-inflammation, prevention of diabetes, and regulation of blood pressure. Various amino acids such as glutamic acid, arginine and arginine dipeptides, which exist in the components of protein hydrolysates, have also been recently recognized as being helpful in decreasing the use of salt in foods as they can greatly enhance salty taste when used concurrently with salt due to having both salty and palatable flavors. In the case of protein hydrolysates that decompose soy protein or fish protein such as anchovy, they could reduce consumption of salt by as much as 50% without affecting people's food preferences when applied to food as they boost salty taste by approximately 10% to 70%. Although there are only a few studies on protein hydrolysates as a salty taste enhancer or salt substitute, the results of several studies are indicative of the potential of protein hydrolysates as a salty taste enhancing ingredient.

• Food Science of Animal Resources
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• v.34 no.2
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• pp.192-199
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• 2014

The effects of adding mechanically deboned chicken (MDC) hydrolysates on the quality characteristics of imitation crab stick (ICS) during storage were investigated. ICS was prepared from Alaska Pollack, chicken breast surimi, and protein hydrolysates enzymatically extracted from MDC. ICS samples were divided into 4 groups: without protein hydrolysate (control), added with 0.5% protein hydrolysate (T1), added with 1.0% protein hydrolysate (T2), and added with 1.5% protein hydrolysate (T3). Results showed that crude protein content did not differ significantly among the ICS samples (p>0.05). ICS sample added with MDC hydrolysates had higher crude fat and ash content but lower moisture content than the control (p<0.05). Lightness was significantly lower in T2 and T3 than in the other groups at 0 and 4 wk of storage. Also, whiteness decreased in the groups contained MDC hydrolysates. Breaking force and jelly strength were higher in samples containing MDC hydrolysates compared to control samples (p<0.05). Additionally, saturated fatty acid contents were lower in the groups containing MDC hydrolysates than in control sample groups (p<0.05). Polyunsaturated fatty acid (PUFA) and essential fatty acids (EFA) were significantly higher in T2 and T3 than the control samples. In particular, all samples containing MDC hydrolysates had reduced thiobarbituric acid-reactive substances (TBARS) values at 4 wk. Free radical scavenging activity also was increased with addition of MDC hydrolysates.

• Food Science of Animal Resources
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• v.36 no.2
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• pp.198-205
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• 2016

This study investigated the effects of bovine plasma protein (PP) hydrolysates on the antioxidant and quality properties of pork patties during storage. Pork patties were divided into 4 groups: without butylated hydroxytoluene (BHT) and PP hydrolysates (control), 0.02% BHT (T1), 1% PP hydrolysates (T2), and 2% PP hydrolysates (T3). Pork patty supplemented with PP hydrolysates had higher pH values and lower weight loss during cooking than the control patties. Results showed that lightness and hardness both decreased upon the addition of PP hydrolysates. All samples containing BHT and PP hydrolysates had reduced TBARS and peroxide values during storage. In particular, 2% PP hydrolysates were more effective in delaying lipid oxidation than were the other treatments. It was concluded that treatment with 2% PP hydrolysates can enhance the acceptance of pork patty.

• Journal of Animal Science and Technology
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• v.63 no.5
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• pp.1159-1168
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• 2021

Ovotransferrin (OTF), an egg protein known as transferrin family protein, possess strong antimicrobial and antioxidant activity. This is because OTF has two iron binding sites, so it has a strong metal chelating ability. The present study aimed to evaluate the improved immune-enhancing activities of OTF hydrolysates produced using bromelain, pancreatin, and papain. The effects of OTF hydrolysates on the production and secretion of pro-inflammatory mediators in RAW 264.7 macrophages were confirmed. The production of nitric oxide (NO) was evaluated using Griess reagent and the expression of inducible nitric oxide synthase (iNOS) were evaluated using quantitative real-time polymerase chain reaction (PCR). And the production of pro-inflammatory cytokines (tumor necrosis factor [TNF]-α and interleukin [IL]-6) and the phagocytic activity of macrophages were evaluated using an ELISA assay and neutral red uptake assay, respectively. All OTF hydrolysates enhanced NO production by increasing iNOS mRNA expression. Treating RAW 264.7 macrophages with OTF hydrolysates increased the production of pro-inflammatory cytokines and the phagocytic activity. The production of NO and pro-inflammatory cytokines induced by OTF hydrolysates was inhibited by the addition of specific mitogen-activated protein kinase (MAPK) inhibitors. In conclusion, results indicated that all OTF hydrolysates activated RAW 264.7 macrophages by activating MAPK signaling pathway.

• Food Science of Animal Resources
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• v.31 no.6
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• pp.886-892
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• 2011

This study investigated the ACE-inhibitory effect of yogurt beverage fortified with hydrolysates as well as the suitability of hydrolysates as a nutraceutical additive to yogurt beverage. Three whey protein hydrolysates hydrolyzed by alcalase, protamex, and trypsin were each added to yogurt beverage at concentrations of 1.25, 2.5, and 5 mg/mL. Yogurt beverage fortified with 2.5 mg/mL of hydrolysates had 61-69% ACE-inhibitory activity, whereas yogurt beverage fortified with 5 mg/mL of hydrolysates showed 74% ACE-inhibitory activity. There were no significant differences in ACE-inhibitory activity between the alcalase or protamex hydrolysates during storage; however, trypsin hydrolysate exhibited significant differences. On the other hand, physicochemical characteristics such as pH (3.47-3.77), titratable acidity (0.81-0.84%), colority, viable cell count, and sensory qualities were not significantly different among the tested yogurt beverage samples during storage. These results showed that yogurt beverage fortified with whey protein hydrolysates maintained antihypertensive activity and underwent no unfavorable changes in physicochemical characteristics regardless of enzyme type.

• Journal of agriculture & life science
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• v.50 no.1
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• pp.155-165
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• 2016

The study investigated the effects of adding bovine plasma protein(PP) hydrolysates on the quality properties of cooked pork patties. Pork patties were prepared as follows: manufactured with pork back-fat(control); replacement of back-fat with 40% olive oil(T1), 40% olive oil and 2% PP hydrolysates(T2), and 40% olive oil and 4% PP hydrolysates(T3). The olive oil modified the fatty acid profiles of the pork patties by lowering the saturated fatty acids(SFAs) percentage. Olive oil and 4% PP hydrolysates addition reduced the level of 2-thiobarbituric acid-reactive substance(TBARS) values in pork patties, compared to the controls. Furthermore, the pork patties with added PP hydrolysates had higher pH values than the control. All samples containing olive oil and PP hydrolysates had increased levels of DPPH radical scavenging activity. In particular, added PP hydrolysates were more effective in increasing antioxidant activity than were the other treatments. Therefore, PP hydrolysates could be used as a natural antioxidative in cooked pork patties.

• Food Science and Preservation
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• v.30 no.3
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• pp.434-445
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• 2023

Hemp (Cannabis sativa L.) seeds have recently been attracting attention as a new high-value-added food material owing to their excellent nutritional properties, and research on the development of functional food materials using hemp seeds is actively progressing. This study aimed to evaluate the antioxidant properties of hemp seed protein hydrolysates. Protein hydrolysates were prepared from defatted hemp seed powder (HS) by enzymatic hydrolysis using five different proteases (alcalase, bromelain, flavourzyme, neutrase, and papain). 2,4,6-trinitrobenzene sulfonic acid (TNBS) assay and SDS-PAGE analysis revealed that HS showed a high degree of hydrolysis after treatment with each enzyme except papain. The total polyphenol content of the protein hydrolysates (<3 kDa) and the RC50 values obtained from two different antioxidant tests showed that alcalase hydrolysate (HSA) had a relatively high level of antioxidant capacity. In addition, treatment with HSA (25-100 ㎍/mL) significantly inhibited linoleic acid peroxidation. These results suggest that hemp seed protein hydrolysates are potential sources of natural antioxidants. Future studies will focus on the identification of active peptides from HSA.