• Korean Journal of Food Science and Technology
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• v.28 no.4
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• pp.678-683
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• 1996

The purpose of this study was to elucidate characteristics of hydrolysates from file-fish flesh with various proteases. File-fish flesh was chopped, homogenized with water, and hydrolysed by 8 different kinds of commercially available protease. High production of peptide was observed in bromelain and neutrase treatment. On the other hand, large amount of free amino acid was observed in esp/sav and pronase treatment. Neutrase and pancreatin hydrolysate contained large amount of 5'-GMP. Organoleptic studies showed that the bromelain, esp/sav and protease hydrolysate had strong bitter taste, while pronase and esp/sav hydrolysate had strong umami taste. From these results, pronase was found to be suitable enzyme for producing file-fish hydrolysate.

• Nutrition Research and Practice
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• v.11 no.5
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• pp.396-401
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• 2017

BACGROUND/OBJECTIVES: In this randomized, placebo-controlled, double-blind study, we evaluated the antihypertensive effects of enzymatic hydrolysate from Styela clava flesh tissue in patients with type 2 diabetes mellitus (T2DM) and hypertension. SUBJECTS/METHODS: S. clava flesh tissue hydrolysate (SFTH) (n = 34) and placebo (n = 22) were randomly allocated to the study subjects. Each subject ingested two test capsules (500 mg) containing powdered SFTH (SFTH group) or placebo capsules (placebo group) during four weeks. RESULTS: In the SFTH group, systolic and diastolic blood pressure decreased significantly 4 weeks after ingestion by 9.9 mmHg (P < 0.01) and 7.8 mmHg (P < 0.01), respectively. In addition, the SFTH group exhibited a significant decrease in hemoglobin $A_{1c}$ with a tendency toward improvement in homeostasis model assessment of insulin resistance, triglyceride, apolipoprotein B and plasma insulin levels after 4 weeks. No adverse effects were observed in other indexes, including biochemical and hematological parameters in both groups. CONCLUSION: The results of our study suggested that SFTH exerts a regulatory, antihypertensive effect in patients with T2DM and hypertension.

• Preventive Nutrition and Food Science
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• v.20 no.4
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• pp.284-291
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• 2015

In this study, we attempted to enrich cyclo-His-Pro (CHP) using enzymatic hydrolysis of yeast and to evaluate the functionality of yeast hydrolysate (YH)-enriched CHP. Flavourzyme offered a better performance in enhancing CHP content than other proteases. The CHP enrichment conditions were optimized as follows: addition of 1% Flavourzyme, 48-h incubation at 60oC, and pH 6.0. The CHP content significantly increased by 20-fold after ultra-filtration (UF). Maximal CHP translation was obtained after heating for 8 h at 50oC and pH 7.0. YH showed poor foaming capacity between pH 3.0 to 9.0. The emulsifying activities of YHs were slightly higher at near acidic pH. Increase in heating temperature and time resulted in decreased CHP content. The results indicate that YH is more heat stable after UF. Therefore, the CHP in YH after UF can be used as a food additive with physiological CHP activity and high heat stability.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.6
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• pp.630-634
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• 2011

Enzymatic hydrolysate of porphyran from Porphyra yezoensis was prepared by treatment with ${\beta}$-agarase. The hydrolysate was fractioned into molecular sizes of <3, 3-30, and 30-300 kDa using an ultrafiltration membrane. The membrane fractions were further separated into neutral and anionic fractions using Dowex $1{\times}8$ ion exchange chromatography. After hydrolysis of porphyran with ${\beta}$-agarase, 23.2% of the starting porphyran was recovered as a neutral fraction of low-molecular weight (<3 kDa), and 28.9% remained as an enzyme-resistant anionic fraction of high molecular weight (>300 kDa). Desulfation of porphyran and $^{13}C$-NMR analysis of the anionic fraction of low molecular weight (<3 kDa) showed that the anionic fraction has a backbone consisting of 3-linked ${\beta}$-D-galactose units alternating with either 4-linked a-L-galactose 6-sulfate or 3, 6-anhydro-a-L-galactose units. These results indicate that porphryan is a copolymer of two moieties, about 25% of which are composed of neoagarose moieties and 75% as anionic moieties.

• Microbiology and Biotechnology Letters
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• v.43 no.2
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• pp.105-111
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• 2015

An alginate degrading enzyme from the Vibrio crassostreae PKA 1002 strain was used to hydrolyze the water extract of Sargassum thunbergii. To obtain the optimum degrading conditions for the S. thunbergii water extract, the mixture of the water extract and enzyme was incubated at 30℃ for 0, 3, 6, 12, and 24 h, and its alginate degrading ability was measured by reducing sugar and viscosity. A temperature of 30℃ for a period of 6 h was found to be the optimal condition for the enhancement of the alginate’s degrading ability. The pH of the enzymatic hydrolysate was not significantly different from that of the water extract. Overall lightness decreased, but redness and yellowness increased after enzymatic hydrolysis. Total phenolic compounds did not differ between the water extract and the enzymatic hydrolysate. DPPH radical scavenging activity and the reducing power of the enzymatic hydrolysate were lower than those of the water extract. However, the chelating effect of the enzymatic hydrolysate (80.08% at 5 mg/ml) was higher than that of the water extract (62.29%). These results indicate that the enzymatic hydrolysate possesses an anti-oxidant activity by way of the action of the chelating effect.

• Journal of Life Science
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• v.10 no.2
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• pp.140-149
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• 2000

In order to utilize marine processing waste which would normally be discarded, cod liver protein was hydrolysed by ${\alpha}$-chymotrysin, and the hydrolysate was investigated for the new angiotensin I converting enzyme (ACE) inhibitor. Thy hydrolysate was separated into three major types, with molecular weight cut-off (MWCO) values less than 10 kDa, 5 kDa and 1 kDa of ultrafiltration membranes, respectively. ACE inhibitory peptides were isolated from the fractions passed through MWCO 1 kDa membrane, and purified by using ion-exchange chromatography on a SP-Sephadex C-25 column, gel filtration on a Sephadex G-15 column, and HPLC on an ODS column. The purity was identified with capillary electrophoresis. The amino acid sequences of two peptides were Met-Ile-Pro-Pro-Tyr-Tyr (IC50=10.9 ${\mu}$M) and Gly-Leu-Arg-Asn-Gly-Ile (IC50=35.0 ${\mu}$M)

• Korean Journal of Food Science and Technology
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• v.47 no.1
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• pp.6-12
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• 2015

This study was performed to determine the optimal hydrolysis conditions for the production of hydrolysates, including water-soluble dietary fiber from Chinese cabbage, with commercial enzymes. The optimal pH and temperature for hydrolysis of the hemicellulose fraction were pH 5.0 and $40^{\circ}C$, and optimal enzyme concentrations were 45 units and 21 units for Shearzyme plus and Viscozyme L, respectively. The yields of the hydrolysate including the water-soluble dietary fiber from the hemicellulose fraction by Shearzyme plus and Viscozyme L were 22.64 and 24.73%, respectively, after a 72 h reaction. The molecular weight distribution of alcohol-insoluble fiber was characterized by gel chromatography; degradation of hemicellulose increased with increasing reaction time. Our results indicate that the hemicellulose fraction was degraded to water-soluble dietary fiber by enzymatic hydrolysis, and its hydrolysate could be utilized as new watersoluble food materials.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.1
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• pp.58-63
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• 2015

The chemical and rheological properties of natural and enzymatically hydrolyzed porphyran isolated from Pyropia yezoensis were investigated. The enzymatic hydrolysate was prepared by hydrolysis of porphyran using ${\beta}$-agarase followed by fractionation based on molecular weight (>300 kDa (Fr-1), 100-300 kDa (Fr-2), 10-100 kDa (Fr-3) and 1-10 kDa (Fr-4) using an ultrafiltration membrane. Each hydrolysate fraction consisted mainly of galactose (42.7-57.5%), 3,6-anhydro galactose (6.5-15.1%) and ester sulfate (8.6-14.1%). The sulfate content of the enzymatically hydrolyzed fractions decreased with an increase in molecular weight, whereas the 3,6-anhydro galactose content increased significantly. The rheological behavior of porphyran and enzymatically hydrolyzed porphyran solutions demonstrated a pseudoplastic behavior, which agrees with the Herschel-Bulkley model. The effect of temperature on the viscosity of the porphyrans and hydolysate fractions were measured and modeled using the Arrhenius equation. The activation energy of the porphyrans and enzymatically hydrolyzed porphyran (Fr-1) increased from 12.30 to 20.29 kJ/mol and 9.06 to 23.84 kJ/mol, respectively with increasing concentrations from 3% to 7%. These data indicate that the extent of the apparent viscosity of porphyran and enzymatically hydrolyzed porphyran are influenced by both temperature and concentration.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.4
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• pp.542-550
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• 2016

This study was carried out to investigate the optimal processing conditions for odor removal and maximal antioxidant effects of oyster (Crassostrea gigas) hydrolysate. The optimal hydrolysis conditions were 3.3% neutrase as the protease, $50^{\circ}C$ as the hydrolysis temperature, and 8.3 h as the hydrolysis time. Fish odor of enzymatic oyster hydrolysate was greatly reduced during Saccharomyces cerevisiae fermentation at $24^{\circ}C$ with 0.5% glucose. The protein content of the fermentation product from oyster hydrolysate powder was 25.7%, which contained the major amino acids Glu, Asp, Lys, Arg, Gly, and Ala, whereas Leu, Ala, Phe, Val, and Tau were abundant free amino acids. The important minor minerals were Zn and Fe. Toxicity against Chang cells was not observed in the fermentation product from the oyster hydrolysate up to $200{\mu}g/mL$. The results suggest that fermentation with S. cerevisiae could reduce the fish odor of enzymatic oyster hydrolysate. The hydrolysate has potential application as a food ingredients and nutraceutical.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.46 no.6
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• pp.1-7
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• 2014

Dissolving part of xylan and lignin in lignocellulosic biomass by base can be used as pretreatment technique. Cork oak was pretreated with sodium hydroxide solution and the pretreatment effects were evaluated with two critical factors - NaOH concentration and pretreatment temperature. Some of xylan and lignin were removed by base pretreatment. At $90^{\circ}C$ and 13% NaOH pretreatment, 22.0% of lignin and 78.8% of xylan removed by base treatment. Enzymatic hydrolysis of cork oak which was pretreated at higher temperature or concentration was further improved. After pretreatment of cork oak with 13% NaOH at $90^{\circ}C$, the conversion rate of cellulose to fermentable sugars were reached up to 91.3%. At ethanol fermentation with enzymatic hydrolysate from different pretreatment conditions, all enzymatic saccharification liquids were well fermented by Saccharomyces cerevisiae.