• Journal of Dairy Science and Biotechnology
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• 제33권4호
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• pp.263-269
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• 2015

본 연구에서는 다양한 낙농 발효유제품에 있어서 다양한 유기산과 탄수화물의 분석이 HPLC 방법으로 동시에 잘 진행되었다. 이 방법의 주요 장점으로는 (1) 간단한 시료 준비와 단일 추출이 가능, (2) 유동상(mobile phase)과 추출 용매에 있어서 편리성과 경제성, (3) 추출제와 유동상에 사용되는 황산의 농도가 매우 낮기에 친환경적인 실험, (4) 하나의 샘플당 30분 안에 HPLC의 분석이 완료 가능, (5) 다양한 농도범위에서도 분석 및 정량 가능, (6) 몇 가지 물질을 제외하고 모든 화합물의 변동계수가 낮음, 그리고 (7) 회수율이 대체적으로 높다는 것이다. 또한, $60{\sim}65^{\circ}C$에서 분석 column을 사용하였기에 column 효율면에서도 손실이 극히 적은 것으로 관찰되었다. 따라서 본 실험에서 분석된 다양한 낙농 발효유제품에서의 acid, 탄수화물, diacetyl, acetoin 등이 HPLC 방법은 매우 신속하고 정확하게 검출되었다. 하지만 다양한 향미의 변화를 최소화하면서 다양한 향미를 효과적으로 추출할 수 있는 HPLC 방법들이 지속적으로 개발되어야 다양한 낙농 발효유제품의 품질개선에 기여할 것으로 사료된다. 왜냐하면 향미 성분의 분석은 성분을 정성하는 것뿐만 아니라, 정성된 화합물이 그 식품의 향에 어느 정도 기여하는지를 중요하게 결정하기 때문이다. 또한 본 실험에 사용된 HPLC 방법으로 다양한 유산균주의 일정한 배양시간동안 유당분해효소(lactase) 능력이 조사 되었는데, 각 Probiotic lactic acid bacteria마다 다양한 유당분해효소(lactase)의 능력을 보였으며, 같은 균종에서도 차이가 있는 것으로 나타났다. 본 실험에서는 Bifidobacterium spp.가 Lactobacillus spp.와 Streptococcus spp.보다 높은 유당분해효소(lactase)의 능력을 보였다. 하지만 유산균주의 유당분해효소 능력을 정확하게 파악하기 위해서는 각 Probiotic lactic acid bacteria의 exo- 및 endo-lactase에 대한 연구가 추가적으로 필요하다. 결론적으로 다양한 낙농발효식품 및 기타 발효식품 등에서 HPLC 방법으로 동시에 유기산과 탄수화물 분석이 공인방법으로써 인정되기 위해서는 더 많은 기초자료 확립과 재현성에 관한 지속적인 연구가 진행되어야 할 것으로 사료된다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제8권2호
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• pp.130-134
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• 2003

A visual method for the selective screen Eng of lignin degrading enzymes, produced by white rot fungi (WRF), was investigated by the addition of coloring additives to solid media. Of the additives used in the enzyme production media, guaiacol and RBBR could be used for the detection of lignin peroxidase (LiP), manganese peroxidase (MnP) and lactase. Syringaldazine and Acid Red 264 were able for the detection of both the MnP and lactase, and the LiP and laccase, respectively, and a combination of these two additives was able to detect each of the ligninases produced by the WRF on solid media.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1996년도 춘계학술대회
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• pp.283-283
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• 1996

The hydrolyzed-lactose milk for the lactase-deficient subject is sweeter than whole milk, and some subjects dislike its taste. To overcome this shortcoming the dried liposomes containing ${\beta}$-galactosidase to digest lactose in milk after drinking were prepared and examined the possible application of this dried liposomes to the lactase-deficient subjects. To improve the stability of conventional liposome suspension, the dried liposomes in the presence of trehalose were prepared by the dehydration-rehydration vesicles method. Small unilamellar vesicles, prepared with egg phosphatidyl cholesterol, and cholesterol, were mixed with ${\beta}$-galactosidase solution and then ;up[jo;ozed. The freeze-dried liposome was rehydrated and centrifuged. The resultant multilamellar vesicles were mixed with trehalose(4g/g lipid) and then lyophilized to produce final dried liposome. Trehalose increased the entrapping efficiency of liposomes by 3 fo1d compared to the liposomes without trehalose (13% vs. 46%).

• Journal of Ginseng Research
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• 제10권1호
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• pp.27-35
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• 1986

본 연구는 인삼중 지용성 성분이 인체암 세포의 증식억제와 암세포내 효소 활성에 미치는 영향을 구명하고자 실시하였다. 인체 장암 세포인 HRT-18, HCT-48 및 HT-29등을 대상으로 인삼추출물 처리시 각 암세포의 증식율과 암세포내 효소 즉, sucrase, lactase, maltase 및 trehalase등 disaccharidas 활성을 측정한 바 다음과 같은 결과를 얻었다. 1. HTR-18, HT-29 및 HCT-48의 doubling time은 각각 약 20, 22, 24시간이 및 되었다. 2. 각 암세포의 증식율은 배양액 중 CX 함량의 증가와 연장에 따라 점차 더 억제되었다. 3. 인삼 extract를 함유하는 배양액에서 배양된 HRT-18 및 HCT-48 암세포의 sucarse활성은 각각 362% 및 577% 증가하였고, lactase(317%, 334%), maltase(134% 및 153%) 및 trehalase(311% 및 203%) 활성도 다 같이 유의성있게 증가하였다.

• 한국환경농학회지
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• 제17권3호
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• pp.239-245
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• 1998

부식형성과정에서 nitroaromatics와 그 환원산물들의 구조에 따른 bound residue형성 양상을 밝히기 위하여 nitrotoluene류, nitrophenol류와 그 환원형태의 화합물 및 nitro기를 가진 살충제 parathion과 amino기를 가진 제초제 asulam을 단독으로 또는 부식을 구성하는 humic monomer들이 존재하는 반응 조건에서 laccase와 HRP를 촉매로 사용하여 그 반응 양상을 조사하였다. Laccase와 HRP를 촉매로 하여 반응시킨 경우, humic monomer의 유무, 종류, nitro기의 결합위치와 수에 관계없이 nitrotoluene류와 nitrophenol류는 laccase와 HRP에 의해 거의 전환되지 않았고, aminotoluene류 및 amino-nitrophenol류는 전부 전환되었다. 일부가 환원된 형태인 amino-nitrotoluene류는 humic monomer에 따라 다른 전환율을 나타내는 데, catechol, syringaldehyde와 protocatechuic acid에서 가장 높은 전환율을 나타내었다. Nitro기가 있는 살충제 parathion은 humic monomer가 존재하는 반응 조건에서 거의 전환되지 않았고, 그 분해산물 4-nitrophenol의 경우도 protocatechuic acid를 제외하고는 거의 전환되지 않았다. Amino기가 있는 제초제 asulam의 경우, humic monomer가 존재하지 않는 조건에서는 거의 전환되지 않았지만 catechol, syringaldehyde, protocatechuic acid 및 caffeic acid의 경우, 비교적 높은 전환율을 나타났다.

• 한국축산식품학회지
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• 제27권3호
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• pp.329-336
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• 2007

This study was designed to find the optimum conditions for converting isoflavone glycoside to aglycone by ${\beta}-galactosidase$. Three different forms of the enzyme were tested and the optimum enzyme concentration, incubation temperature, pH, and incubation time were determined. Before treatment with enzyme, isoflavone contained 89.4% glycoside including daidzin, glycitin and genistin, and only 10.6% aglycone including daidzein, glycitein and genistein. Among the enzymes tested, the highest rate of isoflavone hydrolysis to aglycone, 35%, was observed when 3 unit/g Fungal Lactase (Amano Enzyme) was used. Higher incubation temperatures resulted in a higher rate of hydrolysis along with a greater loss of isoflavone mass. Therefore, body temperature $(37^{\circ}C)$ may be adequate for isoflavone conversion, with 44.9% hydrolysis and less than 10% loss of mass. As expected, a higher amount of aglycone was produced at pH 7 compared with other pH values. During 5hr of incubation, the conversion of glycoside to aglycone increased dramatically from 0 to 1hr, and plateaued thereafter. In addition, commercial soy-based milk was hydrolyzed more effectively with ${\beta}-galactosidase$ when incubated for 5hr. Based on the above results, the optimum conditions for isoflavone hydrolysis by ${\beta}-galactosidase$ were for 3 hr at $37^{\circ}C$, pH 7 with 3 unit/g Fungal Lactase (Amano Lactase), yielding an average total amount of aglycone ranging from 40 to 47%.

• Asian-Australasian Journal of Animal Sciences
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• 제19권10호
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• pp.1470-1477
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• 2006

One hundred and sixty crossbred pigs ($6.62{\pm}0.36kg$) weaned at day $18{\pm}1$ were used to investigate the effects of lactitol and tributyrin on performance, small intestinal morphology and enzyme activity. The pigs were assigned to one of five dietary groups (4 pens/diet with 8 pigs/pen) and were fed the negative control diet or the negative control diet supplemented with 10 g/kg glutamine (as a positive control), or 3 g/kg lactitol (${\beta}$-D-galactopyranosyl-($1{\rightarrow}4$)-D-sorbitol), or 5 g/kg tributyrin (butanoic acid 1,2,3-propanetriyl ester), or 3 g/kg lactitol+5 g/kg tributyrin. Body weight and feed intake were measured weekly during the 4-week study. On day 7, four pigs per dietary treatment were sacrificed to examine small intestinal morphology and enzyme activity. The results showed that: (1) Compared with the negative control diet, the positive control diet improved weight gain and feed efficiency during weeks 1-2 and over the entire study (p<0.05), and also decreased duodenal and ileal crypt depth (p<0.05), but did not alter intestinal enzyme activity (p>0.05). Lactitol improved feed efficiency during weeks 3-4 and over the entire study (p<0.05), but did not improve weight gain and feed intake, intestinal morphology or enzyme activity (p>0.05). Tributyrin improved weight gain and reduced feed/gain during weeks 3-4 and over the entire study. Tributyrin significantly decreased crypt depth in the duodenum and ileum, and increased duodenal lactase and ileal maltase activity (p<0.05). Lactitol+tributyrin increased weight gain during weeks 3-4 and over the entire study, and improved feed efficiency during weeks 1-2 and 3-4 and over the entire study (p<0.05). Lactitol+tributyrin increased the jejunal villus height, and decreased the duodenal and ileal crypt depth (p<0.05). Lactitol+tributyrin also increased jejunal lactase and sucrase activity (p<0.05). (2) Compared with the positive control, tributyrin improved weight gain and reduced feed/gain during weeks 3-4 (p<0.05), decreased the ileal crypt depth, and improved the duodenal lactase and sucrase activity (p<0.05). Lactitol+ tributyrin improved weight gain during weeks 3-4, improved feed efficiency during weeks 3-4 and over the entire study, increased the ileal villus height, and increased jejunal lactase, sucrase and maltase activity (p<0.05). These results showed that tributyrin improved performance, intestinal morphology and enzyme activity, while the effect of lactitol was very limited. These results also showed that, compared with glutamine, tributyrin was more effective in improving intestinal morphology and enzyme activity, and tributyrin exerted a superior effect in improving performance as weaning progressed. These observations suggest that, as a chemical for repairing intestinal atrophy, glutamine and tributyrin should be used in the first and second periods of the starter phase, respectively.

• Journal of Microbiology and Biotechnology
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• 제18권4호
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• pp.695-703
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• 2008

A locally isolated thermophile, Geobacillus sp. SAB-40, producing thermostable extracellular amylase constitutively and an induced intracellular ${\beta}$-galactosidase was characterized and identified based on 16S rRNA sequencing. A phylogenetic analysis then revealed its closeness to Geobacillus stearothermophilus. To evaluate the effect of the culture conditions on the coproduction of both enzymes by G stearothermophilus SAB-40, a Plackett-Burman fractional factorial design was applied to determine the impact of twenty variables. Among the tested variables, $CaCI_2$, the incubation time, $MgSO_4{\cdot}7H_2O$, and tryptone were found to be the most significant for encouraging amylase production. Lactose was found to promote ${\beta}$-galactosidase production, whereas starch had a significantly negative effect on lactase production. Based on a statistical analysis, a preoptimized medium attained the maximum production of amylase and ${\beta}$-galactosidase at 23.29 U/ml/ min and 12,958 U/mg biomass, respectively, which was 3-and 2-fold higher than the yield of amylase and lactase obtained with the basal medium, respectively.

• Journal of Dairy Science and Biotechnology
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• 제38권1호
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• pp.1-18
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• 2020

Lactose intolerance is a pathophysiological phenomenon caused by a deficiency of the enzyme lactase present in human intestines. Changes in intestinal digestion and colon fermentation after the intake of lactose-containing products cause diarrhea and other clinical discomforts. Therefore, lactose intolerance can be easily ameliorated by consuming lactose hydrolyzed milk and dairy products. In the recent years, lactose-free dairy products have provided lactose intolerant consumers with several options, due to an improvement in the quality and an increase in the variety of products. Currently, the manufacturing of lactose-free products also represents the fastest growing sector in the dairy industry. This review, thus, aims to provide an overview of the current availability and prospects of lactose-free dairy products, and also discuss the potential benefits of the development of a variety of lactose-free dairy foods.

• Asian-Australasian Journal of Animal Sciences
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• 제24권4호
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• pp.500-508
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• 2011

Forty-four Gansu Alpine Fine-wool lambs were used to study changes in the activities of three gastric and five pancreatic enzymes under grazing conditions between 0 and 56 days of age. The lambs were slaughtered on days 0, 3, 7, 14, 21, 28, 42 and 56, the abomasal contents, mucosa and pancreas were immediately removed and placed into liquid nitrogen and enzyme activities were determined. Gastric enzyme (chymosin, pepsin and pregastrc esterase) activities were relatively high at birth, especially chymosin, but decreased quickly between day 0 and 21. The activity of pepsin changed insignificantly with increasing age. There was no significant change in the pancreatic enzyme activities (trypsin, chymotrypsin, ${\alpha}$-amylase, lipase and lactase). The activity of trypsin was relatively higher than that of the other pancreatic enzymes, and lactase activity was low. These ontogenic patterns might be under the control of many gut regulatory peptides, the plasma concentrations of which changed simultaneously. Some gastric and pancreatic enzymes were correlated with plasma concentrations of these gut regulatory peptides.