• Title, Summary, Keyword: Lactose

Search Result 863, Processing Time 0.04 seconds

Effects of Lactose and Yeast on the Changes of Oligosaccharides during the Fermentation of Soy Yogurts (Lactose와 효모의 첨가가 대두요구르트 발효 중 올리고당의 변화에 미치는 영향)

  • Park, Mi-Jung;Lee, Sook-Young
    • Korean Journal of Food Science and Technology
    • /
    • v.29 no.3
    • /
    • pp.539-545
    • /
    • 1997
  • Lactobacillus bulgaricus and Kluyveromyces lactis were inoculated to Jangyeob and Jinpum soy milks together after the addition of different amounts of lactose to increase the contents of oligosaccharides, which were compared with single cultured samples. The contents of stachyose, raffinose, sucrose, and glucose of samples without lactose decreased by single culture method, but the oligosaccharides decreased less than in single cultured samples containing of lactose. The oligosaccharides of single cultured samples were equal or decreased compared with soy milks. While those of mixed cultured Jangyeob and Jinpum samples containing 2% lactose for 24 hr incubation increased 125.0% and 118.1%, respectively and those of samples for 36 hr incubation increased 127.0% and 141.0%, respectively, those of mixed cultured samples containing 4% lactose for 24 hr incubation increased 112.5% and 123.0%, respectively and those of samples for 36 hr incubation increased 120% and 135.9%, respectively. Therefore, the oligosaccharides in samples containing 2% lactose were slightly more than in samples containing 4% lactose. Among the cultured methods, oligosaccharides were produced in the largest amounts by the mixed culture for 36 hr. The addition of lactose in soy milks for soy yogurts was effective in the formation of oligosaccharides since the galactose, produced by the hydrolysis of lactose, was thought to be combined with sucrose by the action of ${\beta}-galactosidase$ in yeast.

  • PDF

Effects of Lactose and Yeast on the Growth of Lactic Acid Bacteria and Sensory Characteristics during the Fermentation of Soy Yogurts (Lactose와 효모의 첨가가 대두요구르트 발효 중 젖산균의 생육특성 및 관능적 특성에 미치는 영향)

  • Park, Mi-Jung;Lee, Sook-Young
    • Korean Journal of Food Science and Technology
    • /
    • v.29 no.3
    • /
    • pp.533-538
    • /
    • 1997
  • Lactobacillus bulgaricus and Kluyveromyces lactic were inoculated to Jangyeob and Jinpum soymilks single or together after the addition of different amounts of lactose to increase the formation of lactic acid and sensory evaluation. The decrease of pH and the increase of acid production during the fermentation of soy yogurts were more effective when lactose was added. And the single culture method was more effective in decreasing pH and in increasing acid production than the mixed culture method. Without lactose, the growth of lactic acid bacteria in samples increased by mixed culture method than by single culture method. However, the growth of lactic acid bacteria increased more in the by single cultured samples than in the mixed cultured samples by the addition of lactose. Beany flavor decreased more in soy yogurts compared with Jangyeob and Jinpum soy milks, and Jinpum soy yogurts had less beany flavor than Jangyeob soy yogurts. In sour taste, Jangyeob soy yogurt prepared by mixed culture for 36 hr incubation with 4% lactose showed the poorest score, while soy yogurts containing 2% lactose showed significantly better scores and no significant difference compared with milk yogurt. Soy yogurts containing 2% lactose showed no significant difference in overall acceptability compared with milk yogurt.

  • PDF

Development of Lactose-Free Dairy Products Effective against Lactose Intolerance: Present and Future (유당불내증에 효과적인 유당이 없는 낙농 유제품의 개발: 현재와 미래)

  • Chon, Jung-Whan;Seo, Kun-Ho;Jeong, Dongkwan;Song, Kwang-Young
    • Journal of Dairy Science and Biotechnology
    • /
    • v.38 no.1
    • /
    • pp.1-18
    • /
    • 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.

Galactooligosaccharide and Sialyllactose Content in Commercial Lactose Powders from Goat and Cow Milk

  • Kim, Hyo-Hee;Yun, Sung-Seob;Oh, Chang-Hwan;Yoon, Sung-Sik
    • Food Science of Animal Resources
    • /
    • v.35 no.4
    • /
    • pp.572-576
    • /
    • 2015
  • The most commonly used infant formulas contain lactose originating from cow milk. Goat milk has recently been claimed to be nutritionally more effective for infants than other milks. In baby foods, much emphasis is placed on the concentrations of intestinal microflora-promoting oligosaccharides, which are generally transferred into lactose from milk during crystallization process. Here we show that higher level of free sialic acid is present in goat lactose powder compared to cow lactose powder. Without proteinase K treatment, the amount of 3-sialyllactose and 6-sialyllactose were similar in goat and cow lactose powders. However, after proteolysis, 6-sialyllactose was present at higher levels in goat than in cow lactose powder. Galactooligosaccharides, a group of prebiotics, are present in milk in the form of glycoproteins. Galactooligosaccharide content was also higher in goat lactose powder than in cow lactose powder.

Effect of Lactose on Calcium Absorption Enhanced by Casein Phosphopeptides in the Rat Small Intestine (Casein Phosphopeptides 의 장관내(腸管內) 칼슘 흡수촉진(吸收促進)에 미치는 유당(乳糖)의 영향(影響))

  • Lee, Yeon-Sook;Naito, Hiroshi
    • Journal of Nutrition and Health
    • /
    • v.15 no.1
    • /
    • pp.1-8
    • /
    • 1982
  • The effects of lactose on the formation of casein phosphopeptide (CPP), the increment of soluble calcium and the enhancement of calcium absorption by dietary casein in the intestinal tract were investigated. Rats were fed a lactose-free diet, 10% lactose diet and 30% lactose diet containing powdered milk. In rats receiving a lactose-free powdered milk diet, CPP formation was confirmed by gel filtration of the intestinal content on Sephadex G -25 and the amount of soluble calcium was increased in the small intestine and calcium absorption, measured by the ligated ideal loops in situ was enhanced. However, In rats receiving a powdered milk diet containing 10% lactose or 30% lactose, the similar effects were not seen. These observations indicate that CPP-stimulated effects on soluble calcium and calcium absorption in the small intestine are not dependent upon lactose.

  • PDF

Comparision of Preservation of Liquid Boar Semen between Lactose-Egg Yolk and $B\ddot{u}tschwiler$ Diluents (돼지 액상정액 보존을 위한 Lactose-Egg Yolk와 $B\ddot{u}tschwiler$ 희석액의 비교)

  • Park, C.S.;Cheon, Y.M.;Xu, Z.
    • Korean Journal of Animal Reproduction
    • /
    • v.20 no.2
    • /
    • pp.101-109
    • /
    • 1996
  • This study was done to find out the methods of long-term use of liquid boar semen in 100 ml plastic bottle for artificial insemination and to investigate differences between Lactose-Egg yolk and Biitschwiler diluents according to storage temperature, and effect of final glycerol concent ration in Lactose-Egg yolk diluent. Liquid boar semen diluted with Lactose-Egg yolk diluent showed significantly higher sperm motility (p<0.05) after 0.5 and 2h incubation at 37$^{\circ}C$,than Butschwiler diluent at all storage length when it was preserved in the 5$^{\circ}C$ refrigerator. The NAR acrosome in Lactose-Egg yolk diluent a after 0.5 and 2h incubation at 37$^{\circ}C$, respectively, during preservation periods was similar to that in Biitschwiler diluent. When liquid boar semen was preserved at 15$^{\circ}C$, liquid boar semen in the Butschwiler diluent showed significantly higher percentages of sperm motility and NAR acrosome from third day to seventh than that in Lactose-Egg yolk diluent. In the effect of final glycerol concentration of liquid boar semen in the Lactose-Egg yolk diluent, the final glycerol concentration of 2% showed higer percentages of sperm motility and NAR acrosome than that of 0, 1, 3, and 5%. Farrowing rate, litter size and average pig weight at birth did not differ significantly between Lactose-Egg yolk and But schwiler diluents. As a result of this study, we found out that liquid boar semen can be stored for 6-7 days at 5$^{\circ}C$ in Lactose-Egg yolk diluent and at 15$^{\circ}C$ in Butschwiler diluent.

  • PDF

Effects of Carbon Substrates on Exopolysaccharide Production by Enterobacter sp. (Enterobacter sp. 의 다당 생산에 미치는 탄소원 기질의 영향)

  • Lee Ju-Ha;Lee Shin-Young
    • KSBB Journal
    • /
    • v.20 no.1
    • /
    • pp.26-33
    • /
    • 2005
  • The effects of carbon sources for exopolysaccharide production during batch cultivation of an Enterobacter sp. isolated from the composter were investigated. The highest amount of exopolysaccharide was obtained when lactose was used as carbon source. Lactose in medium was converted into glucose and galactose. Glucose was metabolized fast and was completely consumed, but about $20\%$ of lactose was accumulated as galactose. On the other hand, enzyme activity was about $350\~450$ unit with the increase of lactose concentration. Thus, it was considered that the exopolysaccharide might be produced in the course of that lactose was hydrolyzed into glucose and galactose by $\beta-galactosidase$ with respect to that enzyme activity on lactose hydrolysis was accorded to the exopolysaccharide production. When glucose and galactose were added to lactose medium, respectively, it could be considered that glucose was as a repressor and galactose was as a inducer for $\beta-galactosidase$ synthesis even though the mechanisms were not elucidated. The increase of lactose concentration was almost ineffective to the specific growth rate $(0.133\~0.151\;hr^[-1})$ but showed the difference in the biomass content. The higher carbon source concentration, the more residual sugar remained. It was assumed that the optimum lactose concentration for exopolysaccharide production was $30\~70g/L.$ On the other hand, it was considered that the nitrogen acted as growth limiting nutrients to the cell growth. In the cases of 30 and 70 g/L of the fixed carbon concentrations, the increase of the nitrogen sources concentration caused a remarkable increase within the range of $0.059\~0.225\;hr^{-1}$ and $0.141\~0.237hr^{-1}$ of the specific growth rate, respectively, while there was no significant difference in biomass.

Expression of lac and gal operons in Zymomonas mobilis

  • Cho, Dong-Wuk;Rogers, Peter L.;Delaney, Stephen F.
    • Journal of Microbiology and Biotechnology
    • /
    • v.4 no.2
    • /
    • pp.155-159
    • /
    • 1994
  • Two Zymomonas mobilis strains (ZM63 and ZM6307), containing both lactose and galactose operons, were constructed. $\beta$-Galactosidase and galactokinase assays indicated that both operons were expressed in both strains. The transport systems available for lactose uptake by Zymomonas mobilis were investigated using $^{14}C$-labelled lactose. After the outer membrane, which was considered to be a possible barrier to lactose uptake, was disrupted by treatment with EDTA and $Ca^{2+}$ ions, some increase in lactose uptake was observed in ZM6306 ($lac^+$) and ZM6307 ($lac^+\;gal^+$), but not in the parent, ZM6. This suggested that the outer membrane of Zymomonas mobilis acts as a barrier to lactose uptake to some degree, and also that the lactose permease is operational in Zymomonas mobilis.

  • PDF

Development of Lactose-hydrolyzed Milk with Low Sweetness Using Nanofiltration

  • Choi, S.H.;Lee, S.-B.;Won, H.-R.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.20 no.6
    • /
    • pp.989-993
    • /
    • 2007
  • A lactose-hydrolyzed milk with low sweetness was developed using nanofiltration. Raw milk was treated with 0.03% ${\beta}$-galactosidase at $4^{\circ}C$ for 24 h to hydrolyze lactose partially. The resultant lactose-hydrolyzed milk containing 0.43% lactose was then concentrated using a nanofiltration membrane to reach concentration factor of 2.13. The concentration factors and coefficients of retention of milk components in nanofiltration were determined. The concentration factor of milk fat was 2.20 which was the highest of the milk components. The coefficient of retention of calcium and riboflavin was 0.96 and 0.76, respectively. However, the coefficient of retention of glucose, galactose, and sodium was 0.21, 0.15, and 0.22, respectively. Raw milk was treated with 0.1% ${\beta}$-galactosidase at $4^{\circ}C$ for 40 h to hydrolyze lactose fully and then concentrated to reach a concentration factor of 1.6 by using nanofiltration. The concentrated milk was reconstituted with water. The lactose-hydrolyzed milk had sweetness similar to milk. The compositional ratios of crude protein, calcium, sodium, and riboflavin of lactose-hydrolyzed nanofiltrated milk to those of raw milk were 99%, 97%, 77%, and 80%, respectively. This study showed that nanofiltration of lactose-hydrolyzed milk to remove galactose and glucose did not cause significant loss of calcium. The lactose-hydrolyzed nanofiltrated milk contained 0.06% lactose and had sweetness similar to milk.

Phospho-$\beta$-galactosidase gene located on plasmid in lactobacillus casei (플라스미드에 존재하는 lactobacillus casei의 phospho-$\beta$-galactosidases 유전자)

  • 문경희;박정희;최순영;이유미;김태한;하영칠;민경희
    • Korean Journal of Microbiology
    • /
    • v.27 no.3
    • /
    • pp.181-187
    • /
    • 1989
  • Plasmid DNA was isolated from Lactobacillus casei SW-M1($Lac^{+}$strain). The curing frequencies of pPLac plasmid from L. casei SW-M1 showed 43% for acriflavin treatment and 53% for ethidium bromide treatment after 3 times transfer. On the charaterization of pPLac plasmid, it was found that the plasmid contained gene encoding phospho-$\beta$-galactosidase for lactose utilization. Lactose-PTS(phosphotransferase system)was involved in membrane transport system in $Lac^{+}$ strain. Induction of phospho-$\beta$-galactosidase was specially effective by galactose, lower effect with lactose and glucose but not by IPTG(isopropyl-$\beta$-D-thiogalactoside). This result showed that induction of phospho-$\beta$-galactosidase by IPTG did not appeared. The catabolite repression of phospho-$\beta$-galactosidase synthesis by glucose was not found in L. casei.

  • PDF