• Fisheries and Aquatic Sciences
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• v.25 no.6
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• pp.335-349
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• 2022

To optimize the hydrolysis conditions in the production of antioxidant hydrolysates from tuna cooking juice concentrate (TC) to maximize the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, TC containing 48.91% protein was hydrolyzed with Alcalase 2.4 L, and response surface methodology (RSM) was applied. The optimum hydrolysis conditions included a 2.2% (w/v) Alcalase concentration and 281 min hydrolysis time, resulting in the highest DPPH radical scavenging activity of 66.49% (0.98 µmol Trolox/mg protein). The analysis of variance for RSM showed that hydrolysis time was an important factor that significantly affected the process (p < 0.05). The effects of different drying methods (freeze drying, hot air drying, and vacuum drying) on the DPPH radical scavenging activity and amino acid (AA) profiles of TC hydrolysate (TCH) were evaluated. Vacuum-dried TCH (VD) exhibited an increase in DPPH radical scavenging activity of 81.28% (1.20 µmol Trolox/mg protein). The VD samples were further fractionated by ultrafiltration. The AA profiles and antioxidant activities in terms of the DPPH radical scavenging activity, 2,2'-azino-bis(3-ethylbenzthiazoline)-6-sulfonic acid (ABTS) radical scavenging activity, ferric reducing antioxidant power, and ferrous ion chelating activity were investigated. Glutamic acid, glycine, arginine, and cysteine were the major AAs found in the TCH fractions. The highest DPPH radical scavenging activity was found in the VD-1 fraction (< 5 kDa). The VD-3 fraction (> 10 kDa) exhibited the highest ABTS radical scavenging activity and ferric reducing antioxidant power. The ferrous ion chelating activity was the highest in VD-1 and VD-2 (5 to 10 kDa). In conclusion, this study provided the optimal conditions to obtain high antioxidant activities through TCH production, and these conditions could provide a basis for the future application of TCH as a functional food ingredient.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.2
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• pp.127-132
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• 2014

The effect of thermal pretreatment conditions on hydrolysis characteristics of dairy manure and sawdust mixtures has been evaluated. Thermal pretreatment temperature varied between 35 and $120^{\circ}C$ and the period of the treatment changed between 30 and 1440min (24h). As thermal pretreatment temperature and duration increased, organic material solublization rates were improved. Maximum solubilizations of chemical oxygen demand (SCOD), carbohydrates, and volatile fatty acids(VFAs) were observed when dairy manure treated for one day at $120^{\circ}C$. Although one day treatment duration at $120^{\circ}C$ showed the highest SCOD, soluble carbohydrates, and VFAs concentration, its hydrolysis rate was only about 12%. The results reveal that the thermal pretreatment conditions tried in this study are not enough to solubilize the organic matter contained in dairy manure and sawdust mixtures. In order to maximize hydrolysis performance, the further research needs to determine the factors influences on organic material solubilization in addition to thermal pretreatment temperature and duration.

• Korean Journal of Food Science and Technology
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• v.22 no.3
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• pp.234-240
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• 1990

Attempts have been made to optimize the hydrolysis conditions of the oyster and the mussel by the commercial proteolytic enzymes. Raw materials were digested with seven different commercial enzymes, and their quality parameters measured in terms of degree of hydrolysis and content of free amino nitrogen, nucleic acid-related substances. and free amino acids as well as sensory evaluation of optimization of their hydrolysis conditions. As a result, following enzymes have been disclosed as effective for enzymatic digestion: MKC-HT proteolytic, alcalase 0.6L and thermease for the oyster whereas MKC-acid fungal protease and thermoase for the mussel, respectively.

• KSBB Journal
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• v.23 no.6
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• pp.509-512
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• 2008

The hydrolysis reaction of soybean oil was conducted experimentally by various source enzymes. The analytical result of hydrolysate of soybean oil showed that the compositions were linoleic acid, olic acid, palmitic acid, and stearic acid in order. The enzymes CR-E and CC-E from Candida rufosa and Candida cylindracea had two hold or more hydrolysis conversions than those of Lipase 16, Novozyme 871, and Lipolase-100L under the same conditions. Therefore CR-E and CC-E were selected for further experiments. These two enzymes had similar ranges of optimun conditions as follows: pH 3-6, $35-45^{\circ}C$, and water to soybean oil ratio of 3.3 or above. They finally got conversions 95% above.

• Korean Chemical Engineering Research
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• v.45 no.3
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• pp.291-297
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• 2007

The hydrolysis reaction of sulfur mustard(HD, bis 2-chloroethylsulfide), one type of the blister agents was studied in water to find the operation conditions which can convert HD into less toxic compounds. The reaction was proceeded into two steps. First, 10~20 wt% of HD was hydrolyzed in water at $90^{\circ}C$ for 2 hr and aqueous sodium hydroxide solution(2.1 eq) was subsequently added to the reaction mixture at room temperature. The efficiency of HD hydrolysis at this experimental conditions was greater than 99.99% and the final degradation products of HD were 68 wt% of thiodiglycol, 8 wt% of 1,2-bis(2-hydroxyethylthio)ethane and 24 wt% of bis(2-hydroxyethylthioethyl)ether.

• Korean Chemical Engineering Research
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• v.54 no.1
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• pp.70-74
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• 2016

In this study, the effects of citrate buffer pretreatment conditions (solid-to-liquid ratio, reaction temperature, pH and concentration of buffer) on enzymatic hydrolysis of E. intestinalis for total reducing sugar (TRS) production were investigated. As a results of the citrate buffer pretreatment, a 5.40% hydrolysis yield was obtained under conditions including 1:10 solid-to-liquid ratio, 0.25 M citrate buffer (pH 3.5) at $140^{\circ}C$ for 60 min. The maximum hydrolysis yield of 18.68% was obtained to enzymatic hydrolysis after pretreatment. This result is 1.81 times higher than that of control.

• Applied Biological Chemistry
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• v.35 no.6
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• pp.479-484
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• 1992

This study was undertaken to determine the effects of cultural conditions on cell growth and casein hydrolysis for cell production in order to add Micrococcus sp. LL3 as a potential agent for industrial application with aim of shortening ripening period and improving flavor. Optimum temperature for cell growth and caseinolysis was $30^{\circ}C$ and $37{\circ}C$, respectively, and optimum pH was 7.0. The enzyme remained stable up to $50^{\circ}C$. Hydrolysis patterns of casein were also observed on SDS-PAGE. Both ${\alpha}-casein$ and ${\beta}-casein$ were totally hydrolysed by enzymes from Micrococcus sp. LL3 during culture. A preferential attack on ${\beta}-casein$ was observed. Production of aminopeptidase which cleaved polypeptides was the highest in early stationary phase during cell growth.

• Journal of Ginseng Research
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• v.45 no.2
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• pp.246-253
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• 2021

Background: Ginseng is one of the most valuable herbal supplements. It is challenging to perform quality control of ginseng products due to the diversity of bioactive saponins in their composition. Acid or alkaline hydrolysis is often used for the structural elucidation of these saponins and sugars in their side chains. Complete transformation of the original ginsenosides into their aglycones during the hydrolysis is one of the ways to determine a total saponin group content. The main hurdle of this approach is the formation of various by-products that was reported by many authors. Methods: Separate HPLC assessment of the total protopanaxadiol, protopanaxatriol and ocotillol ginsenoside contents is a viable alternative to the determination of characteristic biomarkers of these saponin groups, such as ginsenoside Rf and pseudoginsenoside F₁₁, which are commonly used for authentication of P. ginseng Meyer and P. quinquefolius L. samples respectively. Moreover, total ginsenoside content is an ideal aggregated parameter for standardization and quality control of ginseng-based medicines, because it can be directly applied for saponin dosage calculation. Results: Different hydrolysis conditions were tested to develop accurate quantification method for the elucidation of total ginsenoside contents in herbal products. Linearity, limits of quantification, limits of detection, accuracy and precision were evaluated for the developed HPLC-MS method. Conclusion: Alkaline hydrolysis results in fewer by-products than sugar elimination in acidic conditions. An equimolar response, as a key parameter for quantification, was established for several major ginsenosides. The developed approach has shown acceptable results in the analysis of several different herbal products.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.48 no.3
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• pp.57-65
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• 2016

Indigo (Polygonum tinctorium L.) is a typical blue dye which had been used from ancient times. This study was going to shade the complicated traditional methods extracting indigo dye by the fermentation and producing as adsorbate on calcium hydroxide, which says so called as the 'Indigo lime'. Accordingly we were going to make indigo through the hydrolysis of the hot water extractives of indigo leaves simply. During hot-water extraction, ${\beta}$-glucosidase which required hydrolysis of the linkage between indigo and glucose was not activated. To achieve this goal, indican was acid-hydrolyzed to glucose and indigo. The acetic acid, citric acid, hydrochloric acid, and sulfuric acid were used for the hydrolysis of hot water extractives. The hydrolysis conditions of extractives performed in water bath at $80^{\circ}C$ for 120 minutes and in an autoclave for 120 minutes. In the acid hydrolysis of extracted indican by hot water, the indican yields of acetic acid and hydrochloric acid hydrolysis were higher than sulfuric acid in water bath. Also, the indican yield of hydrochloric acid hydrolysis was better than sulfuric acid in autoclave. The hot water extracted indican was confirmed by HPLC analysis and its structure was confirmed by UV-Vis and FT-IR spectroscopy, compared with isolated indigo and commercial synthesized indigo. This improved extraction and hydrolysis methods can be replace the traditional indigo making method.

• Journal of the Korean Society of Clothing and Textiles
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• v.36 no.6
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• pp.653-662
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• 2012

This study measured the effect of general pre-treatment on PLA fabrics to confirm the benefits of enzymatic processing on PLA fabrics in the textile industry as well as evaluated the hydrolytic activities of three lipases. The effects of lipase hydrolysis were analyzed through moisture regain, dyeing ability, tensile strength, and surface morphology. As a result, PLA fibers were easily damaged by a low concentration of sodium hydroxide and a low treatment temperature. The optimal treatment conditions of Lipase from Candida cylindracea were pH 8.0, $40^{\circ}C$, and 1,000 U. The optimal treatment conditions for Lipase from Candida rugosa were pH 7.2, $37^{\circ}C$, and 1,000 U. The optimal treatment conditions for Lipase from Porcine pancreas were pH 8.0, $37^{\circ}C$, and 2,000 U. The moisture regain and dyeing ability of PLA fabrics increased and the tensile strength of PLA fabrics decreased. The results of surface morphology revealed that there were some cracks due to hydrolysis on the surface of the fiber.