• Preventive Nutrition and Food Science
• /
• 제12권1호
• /
• pp.58-63
• /
• 2007

Bifidobacteria are probiotic organisms that provide both flavor and health benefits when incorporated as live cultures into commercial dairy products. Because bifidobacteria are very sensitive to environmental conditions (acids, temperature, oxygen, bile salts, the presence of other cultures, etc.), their viability in human gastrointestinal tract is limited. The microencapsulation of bifidobacteria is a process to protect them against harsh environmental conditions, thereby increasing their viability while passing through human gastrointestinal tract. To confirm the survival rate of microencapsulated Bifidobacterium breve CBG-C2 in milk, their survival rate was compared with several kinds of free bifidobacteria and lactic acid bacteria in commercial yogurt products under simulated gastric and small intestinal conditions. Double-microencapsulation of the bacteria was employed to increase the survival rate during digestion. The outer layer was covered with starch and gelatin to endure gastric conditions, and the inner layer was composed of a hard oil for the upper small intestinal regions. Almost all microencapsulted bifidobacteria in the milk survived longer than the free bifidobacteria and lactic acid bacteria in the commericial yogurt products under the simulated gastric conditions. Numbers of surviving free bifidobacteria and lactic acid bacteria in the commercial products were significantly reduced, however, the viability of the microencapsulated bificobacteria in the milk remained quite stable under gastric and small intestine conditions over 3$\sim$6 hrs. Thus double-microencapsualtion of bifidobacteria in milk is a promising method for improving the survival of bifidobacteria during the digestive process.

• 한국식품영양과학회지
• /
• 제31권3호
• /
• pp.378-383
• /
• 2002

우리나라 고유의 조미료인 간장 및 된장, 대중적인 알코올 음료인 맥주를 대상으로 하여 발암성 N-nitrosamine(NA)을 분석하였고, 또 인공타액 및 위액을 혼합하여 in vitro에서 인공소화시킴으로써 섭취 후 생체내에서 생성 가능한 NA를 예측하고자 하였다. 대상시료 중 질산염은 간장에서 0.3~0.9 mg/kg, 된장에서 0.5~1.0 mg/kg, 맥주에서 0.5~1.3 mg/kg, 아질산염 은 모든 시료에서 평 균 0.3 mg/kg이었으며, DMA 및 TMA는 0.5 mg/kg 이하로 정량되 었다. NA를 분석한 결과, 모든 시료에서 NDMA만이 검출되었으며, 간장에서 <0.5~2.7ug/kg, 된장에서는 1.5~3.1ug/kg, 맥주에서는 <0.5~1.8ug/kg으로 정량되었고, 인공소화 후에는 각각 1.1배, 4.5배 및 1.6배 증가되었다. 아질산염을 농도별로 첨가하여 인공소화시킬 때 모든 시료에서 대조구에 비하여 아질산염의 농도가 높아질수록 NDMA가 증가되었고, 인공소화시 6.4 mM의 thiocyanate를 맥주에 첨가할 때 대조구에 비해 NDMA가 무려 3.3배로 가장 많이 증가하였다. Ascorbic acid를 첨가하여 인공소화시킨 결과전 시료에서 NDMA의 생성이 억제되었으며 특히 12.8 mM의 ascorbic acid를 첨가한 된장에서 NDMA 생성은 약 92.3%나 억제되었다.

• Food Science and Biotechnology
• /
• 제17권3호
• /
• pp.564-568
• /
• 2008

The effects of sodium copper chlorophyllin (SCC) on bioaccessibility and uptake of mercury from fish were investigated using an in vitro digestion coupled with a Caco-2 cell. Fish along with SCC was subjected to a simulated in vitro digestion, which simulates both the gastric and small intestinal phase in vivo. Mercury bioaccessibility, the amount of mercury released from fish to aqueous phase following a digestion, was measured. Various amounts of SCC (0.1-25 mg) significantly reduced mercury bioaccessibility in a dose dependent manner by 49-89% compared to the negative control (fish without SCC) (p<0.05). Mercury bioaccessibility in varying molar ratios of mercury to positive control, 2,3-dimercapto-1-propane sulfonate (DMPS) was between 24 and 52%. Mercury uptake by Caco-2 cells from test media containing aqueous phase following in vitro digestion was measured after 6 hr incubation at $37^{\circ}C$. Cellular mercury uptake with increasing amount of SCC ranged from 0.352 to $0.052\;{\mu}g$ mercury/mg protein, while those in DMPS treatment were between 0.14 and $0.27\;{\mu}g$ mercury/mg protein. Our study suggests that SCC can reduce mercury absorption following fish consumption and may be efficient as a synthetic chelating agent for long term chronic mercury exposure in fish eating populations.

• 한국식품위생안전성학회지
• /
• 제17권2호
• /
• pp.94-100
• /
• 2002

본 실험에서는 우리나라에서 널리 애용되고 있는 전통 발효식품인 김치와 젓갈류 중의 NA와 전구물질의 함량을 분석하고 인공타액 및 위액을 혼합하여 in vitro상에서 소화시킴에 따라 이들 식품의 섭취 후 체내에서 생성될 수 있는 NA의 함량을 예측하고자 하였다. 질산염은 김치에서 10.7~24 mg/kg, 멸치젓에서 1.5~5.6 mg/kg, 새우젓에서 1.0~2.0 mg/kg 아질산염은 모든 시료에서 평균 0.3 mg/kg이 검출되었다. DMA는 새우젓에서 함량차가 매우 커 30.3~177.9 mg/kg의 범위였고, TMA는 김치에서 0.6~0.8 mg/kg, 멸치젓에서 1.9~2.8 mg/kg, 새우젓에서는 4.4~2l.3 mg/kg으로 정량되었다. NA를 분석한 결과 NDMA가 김치에서 0.8~6.9 $\mu\textrm{g}$/kg, 멸치젓에서 불검출~l.2 $\mu\textrm{g}$/kg, 새우젓에서는 불검출~0.9 $\mu\textrm{g}$/kg의 범위로 검출되었고, 인공소화시킨 후에는 모든 시료에서 약 1.5배 증가하였다. 각 시료에 아질산염을 첨가하여 인공소화시킨 경우 모든 시료에서 무첨가군에 비하여 아질산염의 농도에 비례하여 NDMA의 생성량이 증가하였는데, 특히 새우젓에서는 8mM의 아질산염 첨가시 NDMA는 183배 증가하여 220.9 $\mu\textrm{g}$/kg이 검출되었다. 인공타액에 thiocyanate를 1.6, 3.2, 6.4mM 농도로 가하여 인공소화시킨 결과 무첨가구에 비해 NDMA생성량은 약 1.5배 증가하였고 아스코르브산을 농도별로 첨가하여 인공소화시킬 경우 NDMA생성량은 아스코르브산의 농도와 반비례하였고 12.8 mM첨가시 김치는 92.4% 멸치젓과 새우젓은 각각 50.0%, 82.46%의 생성억제 효과가 있었다.

• Food Science and Biotechnology
• /
• 제15권4호
• /
• pp.523-528
• /
• 2006

The digestibility of heat- or high-pres sure-treated beef extracts was evaluated with an in vitro simulated gastric digestion model and each sample also underwent immune assay to detect its antigenicity with the sera of beef allergic patients. Heat treatment of the beef extracts considerably decreased their digestibility, whereas high-pressure treatment at 200 MPa improved their digestibility compared with the control, but the difference was not significant. The digestibility of the high pressure-treated beef extract was generally higher than that of the heat-treated samples. Depending on the degree of digestion, the degree of antigenicity of the main beef allergens decreased. On the basis of these results, we hypothesized that the allergenicity of beef could be eliminated if the allergenic proteins are sufficiently digested in the digestive organ, leading to the suggestion that the digestibility of allergenic proteins must be improved in food processing. In conclusion, high-pressure processing is a more acceptable food processing technique for beef considering its digestibility.

• 한국식품위생안전성학회지
• /
• 제15권2호
• /
• pp.101-107
• /
• 2000

우리나라 고유의 염건품인 굴비를 섭취하였을 때 체내에서 생성되는 NA를 예측하기 위해서 인공타액과 위액을 혼합하여 37。C에서 2시간동안 배양한 굴비의 인공소화물로부터 NA를 분석하였고, 동시에 nitrite, thiocyanate 및 ascorbic acid가 공존할 경우 NA생성에 미치는 영향을 실험하였다. 굴비시료에 인공타액과 위액을 가하여 소화시킨 인공소화물에서는 N-nitrosodimethylamine(NDMA)이 전혀 검출되지 않았으나, nitrite농도를 증가시킬수록 이에 비례하여 NDMA의 생성은 증가하였다. 굴비시료에 thiocyanate를 농도별(0∼6.4 mM)로 첨가하여 인공소화 시킨 결과 nitrite첨가량에 비례하여 NDMA 생성이 증가되었으나, 고농도의 nitrite(100 mM)를 함유한 시료에 thiocyanate를 8mM이상 첨가한 경우에는 뚜렷한 촉매효과를 나타내지 않았다. 반면에 10g의 굴비시료에 ascorbic acid를 농도별로 첨가한 인공 소화물에서 NDMA생성억제를 실험한 결과 nitrite농도가 0.5 및 1 mM인 경우에는 NDMA의 생성을 억제시키지 못하였으나 nitrite와 ascorbic acid의 농도가 높아짐에 따라 비례적으로 NDMA 생성억제도 뛰어났다.

• 한국식품영양학회지
• /
• 제15권1호
• /
• pp.16-22
• /
• 2002

녹차 및 매실추출물이 아질산염 소거, 전자 공여능 및 NDMA 생성 억제에 미치는 영향을 분석하고, 질산염과 아민이 풍부한 식단(CW)에 인공타액과 위액을 이용한"simulated digestion"에서 확인하였다. 녹차와 매실 추출물의 아질산염 소거작용을 pH 1.2,4.2 및 6.0에서 실험한 결과, pH가 낮을수록, 시료 첨가량이 많을수록 효과적이었으며 pH 1.2에서 녹차 추출물 0.5ml 첨가시킬 경우 99.6%의 높은 소거작용을 나타내었고, 매실 추출물 3ml 첨가시 77.2%의 소거작용을 나타내었다. 녹차 및 매실 추출물의 전자공여 시용은 각각 70.6%, 75.1%로 높게 나타났다. 녹차와 배 신 추출물의 NDMA 생성억제 효과는 pH 1.2에시 가장 뛰어났을, 시료량이 증가할수록 억제효과가 높아 3ml 첨가시에 82.1%와 73.2%의 억제효과를 나타내었다. 실험식이에 녹차 및 매실 추출물의 텀가량을 달리하여 인공소화시킬 때 NDMA생성억제 효과는 시료 첨가량에 비례하여 각각 20m1첨가시 녹차 추출물은 57.9%, 매실 추출물은 48.4%의 NDMA 생성 억제 효과를 나타내었다.

• Journal of Nutrition and Health
• /
• 제29권8호
• /
• pp.861-866
• /
• 1996

Tannins in plant foods and beverages may produce antinutritional or toxic effects although some proteins with high affinity for tannins seem to function as defense mechanism to tannin toxicity. Our objectives were to investigate of tea tannins, iron and protein and to evaluate the role of proteins in tannin effects on iron solubility. Iron solubility in vitro was measured using tea with and without proteins. Mixtures of tea, protein in varying concentrations(either gelatin or bovine serum albumin), and iron(eithe 10 or 50ug/mL) were prepared. Controls contained water in place of tea. Iron bioavailability was assessed by measuring iron solubility in the simulated gastric condition with pepsin digestion. Bound iron was removed by centrifugation and soluble in tea alone. When iron concentratin was 10ug/mL, addition of small amounts of protein to tea dramatically reduced iron solubility, but solubility of iron increased in the tea mixturea as the concentration of protein was increased. The percnetage of iron that precipitated was much greater at 10ug Fe/mL than the values at 50ug Fe/mL suggesting that the iron binding sites on the tea-protein complex was saturated. These results suggest that interactions of iron with tea tannins are influenced by the concentratins of protein and iron.

• 한국미생물·생명공학회지
• /
• 제49권2호
• /
• pp.201-209
• /
• 2021

Agarwood (Aquilaria spp) has high economic value. However, essential oil production from agarwood is a time-consuming process. Additionally, agarwood leaves have not been utilized even though they contain various bioactive ingredients. In this study, agarwood leaves were fermented using Lactobacillus plantarum ATCC 8014 with or without Stevia (4, 8, and 12%; v/v). The fermented fluid was mixed with maltodextrin (15%; w/v) and subjected to spray drying (inlet temperature, 120℃; outlet temperature, 65-70℃). The contents of polyphenols, polysaccharides, saponins, and flavonoids and the viability of L. plantarum were determined. Fermentation enhanced the levels of bioactive compounds. The contents of polyphenol (69.19 ± 4.05 mg GAE/g of sample), polysaccharide (20.75 ± 0.98 mg GE/g of sample), saponin (305.23 ± 4.21 mg OAE/g of sample), and flavonoid (7.86 ± 0.72 mg QE/g of sample), and the viability of L. plantarum (8.72 ± 0.17 log CFU/ml) were markedly upregulated in the samples containing Stevia (12%; v/v). This indicated that the supplementation of Stevia during fermentation decreases the fermentation time (9 h), upregulates bioactive compound production in agarwood leaves, enhances microencapsulation during spray drying, and increases the viability of L. plantarum under simulated gastric digestion conditions.

• Journal of Microbiology and Biotechnology
• /
• 제23권6호
• /
• pp.794-801
• /
• 2013

This paper reports the production and characterization of crude xylanase from the newly isolated Humicola sp. Ly01. The highest (41.8 U/ml) production of the crude xylanase was obtained under the optimized conditions (w/v): 0.5% wheat bran, 0.2% $KH_2PO_4$, and 0.5% peptone; initial pH 7.0; incubation time 72 h; $30^{\circ}C$; and 150 rpm. A considerable amount of the crude xylanase was induced using hulless barley bran or soybean meal as the carbon source, but a small amount of the enzyme was produced when supplementary urea was used as the nitrogen source to wheat bran. The crude xylanase showed apparent optimal cellulase-free xylanase activity at $60^{\circ}C$ and pH 6.0, more than 71.8% of the maximum xylanase activity in 3.0-30.0% (v/v) ethanol and more than 82.3% of the initial xylanase activity after incubation in 3.0-30.0% (v/v) ethanol at $30^{\circ}C$ for 2 h. The crude xylanase was moderately resistant to both acid and neutral protease digestion, and released 7.9 and 10.9 ${\mu}mol/ml$ reducing sugar from xylan in the simulated gastric and intestinal fluids, respectively. The xylooligosaccharides were the main products of the hydrolysis of xylan by the crude xylanase. These properties suggested the potential of the crude enzyme for being applied in the animal feed industry, xylooligosaccharides production, and high-alcohol conditions such as ethanol production and brewing.