• Journal of Dairy Science and Biotechnology
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• 제41권1호
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• pp.34-43
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• 2023

Hydrolysis of whey-derived proteins using lactic acid bacteria (LAB) utilizes the mass culture method and fermentation of LAB to produce effective bioactive peptides. Whey protein has the biological potential of its precursors, but the active fragments may not be released depending on the hydrolysis method. As an alternative to these problems, the nutritional and bioactive functionality of the hydrolysis method have been reported to be improved using LAB for whey protein. Peptide fractions were obtained using a sample fast protein liquid chromatography device. Antioxidant activity was verified for each of the five fractions obtained. In vitro cell experiments showed no cytotoxicity and inhibited nitric oxide production. Cytokine (IL [interleukin]-1α, IL-6, tumor necrosis factor-α) production was significantly lower than that of lipopolysaccharides (+). As a result of checking the amino acid content ratio of the fractions selected through the AccQ-Tag system, 17 types of amino acids were identified, and the content of isoleucine, an essential amino acid, was the highest. These properties show their applicability for the production of functional products utilizing dietary supplements and milk. It can be presented as an efficient method in terms of product functionality in the production of uniform-quality whey-derived peptides.

• Journal of Microbiology and Biotechnology
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• 제15권1호
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• pp.40-47
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• 2005

Modeling and simulation for simultaneous saccharification and fermentation (SSF) process in bioconversion of paper mill sludge to lactic acid was carried out. The SSF process combined the enzymatic hydrolysis of paper mill sludge into glucose and the fermentation of glucose into lactic acid in one reactor. A mathematical modeling for cellulose hydrolysis was developed, based on the proposed mechanism of cellulase adsorption deactivation. Another model for simple lactic acid fermentation was also made. A whole mathematical model for SSF was developed by combining the above two models for cellulose hydrolysis and lactic acid fermentation. The characteristics of the SSF process were investigated using the mathematical model.

• 한국식품영양과학회지
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• 제35권10호
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• pp.1420-1426
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• 2006

여러 유도체 형태로 존재하는 대두 isoflavone을 산 가수 분해 방법 및 시간을 달리하면서 isoflavone 배당체의 aglycone으로의 전환율 및 aglycone의 분해여부를 실험하였다. 산 가수분해시 가열처리 조건을 $105^{\circ}C$ 항온기, $95^{\circ}C$ 수욕조, $120^{\circ}C$ heating block 및 hot plate로 달리한 결과 환류냉각장치를 이용하고 heating block에서 가수분해시키는 방법이 가장 적절한 가수분해 방법인 것으로 나타났다. 가수분해 시간 동안 aglycone의 안정성을 검토한 결과 적정 가수분해 시간인 60분 동안에는 genistein, daidzein 및 glycitein 모두 큰 함량변화가 없었다. 가수분해하는 시료의 양과 산의 비율은 시료 $10\sim30mg$당 1 N HCl 용액 1 mL의 비율이 적정하였다. 이상의 결과로부터 정량법은 0.5 g의 대두 시료에 1 N HCl용액 15 mL를 첨가하고 $120^{\circ}C$의 heating block에서 60분간 가수분해시킨 후 methanol로 50 mL로 정용하고 HPLC로 분석하도록 확립하였다. 이에 따라 대두 가공부산물의 iosflavone을 분석한 결과 착유 및 착유 후 hexane 제거를 위한 열처리 공정에서 isoflavone의 손실은 적은 것으로 나타났다.

• KSBB Journal
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• 제28권6호
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• pp.366-371
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• 2013

Ethanol productions were performed by separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) processes using seaweed, Enteromorpha intestinalis (sea lettuce). Pretreatment conditions were optimized by the performing thermal acid hydrolysis and enzymatic hydrolysis for the increase of ethanol yield. The pretreatment by thermal acid hydrolysis was carried out with different sulfuric acid concentrations in the range of 25 mM to 75 mM $H_2SO_4$, pretreatment time from 30 to 90 minutes and solid contents of seaweed powder in the range of 10~16% (w/v). Optimal pretreatment conditions were determined as 75 mM $H_2SO_4$ and 13% (w/v) slurry at $121^{\circ}C$ for 60 min. For the further saccharification, enzymatic hydrolysis was performed by the addition of commercial enzymes, Celluclast 1.5 L and Viscozyme L, after the neutralization. A maximum reducing sugar concentration of 40.4 g/L was obtained with 73% of theoretical yield from total carbohydrate. The ethanol concentration of 8.6 g/L of SHF process and 7.6 g/L of SSF process were obtained by the yeast, Saccharomyces cerevisiae KCTC 1126, with the inoculation cell density of 0.2 g dcw/L.

• Preventive Nutrition and Food Science
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• 제21권2호
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• pp.132-137
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• 2016

Enhanced production of individual phenolic compounds by subcritical water hydrolysis (SWH) of pumpkin leaves was investigated at various temperatures ranging from 100 to $220^{\circ}C$ at 20 min and at various reaction times ranging from 10 to 50 min at $160^{\circ}C$. Caffeic acid, p-coumaric acid, ferulic acid, and gentisic acid were the major phenolic compounds in the hydrolysate of pumpkin leaves. All phenolic compounds except gentisic acid showed the highest yield at $160^{\circ}C$, but gentisic acid showed the highest yield at $180^{\circ}C$. The cumulative amount of individual phenolic compounds gradually increased by 48.1, 52.2, and $78.4{\mu}g/g$ dry matter at $100^{\circ}C$, $120^{\circ}C$, and $140^{\circ}C$, respectively, and then greatly increased by $1,477.1{\mu}g/g$ dry matter at $160^{\circ}C$. The yields of caffeic acid and ferulic acid showed peaks at 20 min, while those of cinnamic acid, p-coumaric acid, p-hydroxybenzoic acid, and procatechuic acid showed peaks at 30 min. Antioxidant activities such as 2,2-diphenyl-1-picrylhydrazyl and ferric reducing antioxidant power values gradually increased with hydrolysis temperature and ranged from 6.77 to 12.42 mg ascorbic acid equivalents/g dry matter and from 4.25 to 8.92 mmol $Fe^{2+}$/100 g dry matter, respectively. Color $L^*$ and $b^*$ values gradually decreased as hydrolysis temperature increased from $100^{\circ}C$ to $140^{\circ}C$. At high temperatures ($160^{\circ}C$ to $220^{\circ}C$), L* and b* values decreased suddenly. The $a^*$ value peaked at $160^{\circ}C$ and then decreased as temperature increased from $160^{\circ}C$ to $220^{\circ}C$. These results suggest that SWH of pumpkin leaves was strongly influenced by hydrolysis temperature and may enhanced the production of phenolic compounds and antioxidant activities.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 추계학술대회 논문집
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• pp.67-70
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• 2008

Biological conversion of biomass into fuels and chemicals requires hydrolysis of the polysaccharide fraction into monomeric sugars. Hydrolysis can be performed enzymatically, and with dilute or concentrate mineral acids. In this study, dilute sulfuric acid used as a catalyst for the hydrolysis of rapeseed straw. The purpose of this study is to optimize the hydrolysis process in a 15ml bomb tube reactor and investigate the effects of the acid concentration, temperature and reaction time on the hemicellulose removal and consequently on the production of sugars (xylose, glucose and arabinose) as well as on the formation of by-products (furfural, 5-hydroxymethylfurfural and acetic acid). Statistical analysis was based on a model composition corresponding to a $3^3$ orthogonal factorial design and employed the response surface methodology (RSM) to optimize the hydrolysis conditions, aiming to attain maximum xylose extraction from hemicellulose of rapeseed straw. The obtained optimum conditions were: acid concentration of 0.77%, temperature of $164^{\circ}C$ with a reaction time of 18min. Under these conditions, 75.94% of the total xylose was removed and the hydrolysate contained 0.65g $L^{-1}$ Glucose, 0.36g $L^{-1}$ Arabinose, 3.59g $L^{-1}$ Xylose, 0.51g $L^{-1}$ Furfural, 1.36g $L^{-1}$ Acetic acid, and 0.08g $L^{-1}$ 5-hydroxymethylfurfural.

• 한국염색가공학회지
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• 제29권4호
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• pp.181-194
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• 2017

The biodegradability of polylactic acid(PLA) fabrics was evaluated by two methods: enzyme and soil degradation. Three different enzymes were selected to evaluate. Degradation times were measured at optimal enzyme treatment conditions. Biodegradation by enzymatic hydrolysis was compared with soil degradation. As a result, biodegradation created cracks on the fiber surface, which led to fiber thickening and shortening. In addition, new peak was observed at $18.5^{\circ}$ by degradation. Moreover, cracks indicating biofragmentation were confirmed by enzyme and soil degradation. By enzyme and soil degradation, the weight loss of PLA fabrics was occurred, there through, the tensile strength decreased about 25% by enzyme hydrolysis when 21 days after, and 21.67% by soil degradation when 60 days after. Furthermore, the biodegradability of PLA fabrics by enzymatic and soil degradation was investigated and enzymatic degradation was found to be superior to soil degradation of PLA fabrics. Among the three enzymes evaluated for enzymatic degradation, alcalase was the most efficient enzymes. This study established the mechanism of biodegradation of PLA nonwovens, which might prove useful in the textile industry.

• 한국미생물·생명공학회지
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• 제24권2호
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• pp.213-216
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• 1996

Optically active carboxylic acid, D-(-)-$\beta$-hydroxyisobutyric acid {(D)-(-)-HIBA} is a useful chiral starting material for the preparation of enantiomerically pure bioactive compounds which have a chiral methyl carbon center in the molecule such as captopril, $\alpha$-tocopherol, erythromycin A, muscone and so on. (S)-3-Acetoxy-2-methylpropanol can be used as the precursor of (D)-(-)-HIBA, that is, chemical oxidation of the hydroxyl group and subsequent hydrolysis of acyl group in (S)-3-acetoxy-2-methylpropanol affords D-(-)-$\beta$-hydroxyisobutyric acid. (S)-3-Acetoxy-2-methyl-propanol was prepared by lipase-catalyzed asymmetric hydrolysis. In the enzymatic hydrolysis system, lipase AY (Candida rugosa) provided the expected (S)-3-acetoxy-2-methylpropanol in 60% e.e. of the enantiomeric purity under the phosphate buffer and organic co-solvent system.

• Fisheries and Aquatic Sciences
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• 제12권1호
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• pp.16-23
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• 2009

Lipids were extracted from marine rotifer, Brachionus rotundiformis in order to examine the functionality of lipid enzymatic modification. The fatty acids, palmitic, linoleic, oleic and stearic acids were the dominant forms accounting for approximately 35.8%, 21.5%, 15.9% and 7.7% of the total lipid content, respectively. Lipid fractions were categorized as neutral lipids (38.5%), glycolipids (45.9%) and phospholipids (17.6%), and after extraction from the rotifer were isolated by thin-layer chromatography (TLC) as free fatty acids (FFA), monoacylglycerol (MAG), diacylglycerol (DAG) and triacylglycerol (TAG). The production of polyunsaturated fatty acid (PUFA) concentrate from rotifer lipids was studied using lipase-catalyzed hydrolysis. In addition, rotifer lipids were modified by hydrolysis using lipases such as porcine pancreas, Candida rugosa and Rhizomucor miehei. The lipase from Rhizomucor miehei was effective in extracting linoleic acid (C 18:2), while the lipase from Candida rugosa was effective in palmitic acid (C16:0) extraction.

• Journal of Industrial and Engineering Chemistry
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• 제68권
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• pp.301-310
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• 2018

Various catalysts such as formic acid, acetic acid, sodium hydroxide, sodium bicarbonate, carbon dioxide and nitrogen gas were used for hydrolyzates production from deoiled mackerel muscle by subcritical water hydrolysis. Above 99% hydrolysis yield was obtained using sodium bicarbonate catalyst at $260^{\circ}C/70bar$. Histamine and heavy metals concentration were reduced in hydrolyzates. Highest amount of amino acid (400.36 mg/g) and reducing sugar (24.75 mg/g) were found in hydrolyzate obtained at $260^{\circ}C/70bar$ and $220^{\circ}C/30bar$, respectively with sodium bicarbonate catalyst. Antioxidant and ACE-inhibitory activities were significantly higher in hydrolyzates obtained using sodium bicarbonate than that of others.