• 한국식품조리과학회지
• /
• 제24권6호
• /
• pp.735-741
• /
• 2008

The principal objective of this study was to evaluate the quality characteristics of yogurt to which had been added extracts of low quality dried persimmons, in an attempt to expand the range of use of low-quality dried persimmons. In the results of our sensory evaluation, our optimal results were attained with the addition of 5 g of dried persimmon extracts, 90 g of water, 20 g of oligosaccharide, and 50 g of fructose at a specific level of 1000 mL. During the 20-day storage period, the pH value of the dried persimmon yogurt was lowest on the 15th day in the control group and the 20th day in the yogurt to which 0.5% extract had been added. The titratable acidity was lowest by a significant margin on the 10th day for all types of yogurt. Viscosity assays showed a stable level of acidity over different storage periods. The number of viable cells demonstrated a trend toward increase with passing time, and the number of viable cells in the dried-persimmon yogurt was higher than that in the control yogurt.

• Preventive Nutrition and Food Science
• /
• 제6권2호
• /
• pp.96-100
• /
• 2001

Mixtures prepared from whole milk with added skin milk powder(2.5%, w/v) and Angelica keiskei juice (1.5%, w/v) were fermented with lactic acid bacteria (single and mixed culture of Lactobacillus bulgaricus and Strpetococcus thermophilus) for 24 hours. The fermented mixtures (curd yogurt) were evaluated for acid production (pH and titratable acidity), cell numbers, viscosity, sensory property and keeping quality. Results indicated that the addition of Angelica keiskei stimulated the acid production by lactic acid bacteria. The number of viable cells reached 4.5~7.3$\times$10$^{9}$ CFU/mL for Angelica keiskei-added yogurts, while 3.3~5.1$\times$10$^{9}$ CFU/mL for control yogurts. Viscosity of Angelica keiskei-added yogurts was higher (3,609~3,854 centipoises) than that of control yogurts(3,346~3,700 centipoises). Of the microorganism tested, mixed culture of Lactobacillus bulgaricus and Streptococcus thermophilus was most effective in acid production. The overall sensory score showed that Angelica keiskei yogurt fermented with Streptococcus thermophilus was evaluated as good as control yogurt. When yogurts were stored at 4$^{\circ}C$ for 12 days, pH, titratable acidity and viable cells of lactic acid bacteria were not significantly changed(p<0.05).

• Journal of Ginseng Research
• /
• 제34권4호
• /
• pp.321-326
• /
• 2010

Enzymatic treatment conditions for red ginseng residue (RGR) were investigated to apply RGR as a microbial medium. Polysaccharide hydrolyase and protease were screened to obtain high solid and carbohydrate yields, and a good degree of carbohydrate hydrolysis. The optimal dosage and reaction time for Viscozyme, the chosen polysaccharide hydrolyase, were found to be 1.0% (w/w) and 3 h, respectively. Of the tested proteases, Flavourzyme, whose optimal dosage was 0.5% (w/w), was selected. Co-treatment with the optimal dosages of Flavourzyme and Viscozyme increased solid yield, carbohydrate yield, and degree of carbohydrate hydrolysis by 76%, 65%, and 1,865%, respectively, over levels in non-treated RGR. The culture characteristics of Leuconostoc mesenteroides strain KACC 91459P grown in enzymatically hydrolyzed red ginseng residue (ERGR) and RGR suspensions were compared. After cultivation for 6 h, the viable cell counts of both cell suspensions rapidly increased to $1.3{\times}10^9$ colony-forming units (CFU)/g. Moreover, while the viable cell population drastically decreased to $2.4{\times}10^6\;CFU/g$ for cells grown in RGR medium, it was maintained in cells fermented in ERGR medium for 24 h.

• Journal of Microbiology
• /
• 제42권2호
• /
• pp.74-79
• /
• 2004

Ingestion of shellfish-associated Vibrio parahaemolyticus is the primary cause of potentially severe gas-troenteritis in many countries. However, only Kanagawa phenomenon (hemolysin) positive (KP$\^$+/) strains of V. parahaemolyticus are isolated from patients, whereas >99％ of strains isolated from the environment do not produce this hemolysin (i.e. are KP$\^$-/). The reasons for these differences are not known. Following a temperature downshift, Vibrio parahaemolyticus enters the viable but noncultur-able (VBNC) state wherein cells maintain viability but cannot be cultured on routine microbiological media. We speculated that KP$\^$+/ and KP$\^$-/ strains may respond differently to the temperature and salinity conditions of seawater by entering into this state which might account for the low numbers of cul-turable KP$\^$+/ strains isolated from estuarine waters. The response of eleven KP$\^$+/ and KP$\^$-/ strains of V. parahaemolyticus following exposure to a nutrient and temperature downshift in different salinities, similar to conditions encountered in their environment, was examined. The strains included those from which the KP$\^$+/ genes had been selectively removed or added. Our results indicated that the ability to produce hemolysin did not affect entrance into the VBNC state. Further, VBNC cells of both biotypes could be restored to the culturable state following an overnight temperature upshift.

• Journal of Dairy Science and Biotechnology
• /
• 제39권1호
• /
• pp.20-26
• /
• 2021

Lactase (β-galactosidase) is abundant in the small intestine during early childhood and gradually decreases with age. Lactic acid bacteria (LAB) present in yogurt could survive in the stomach, and lactase produced by these LAB can aid in lactose breakdown in the small intestine, thereby reducing lactose intolerance. This study aims to provide preliminary data for development of lactose-free yogurts for the elderly, and investigate the effect of lactose-hydrolyzed milk on the growth of starter cultures. The pH during yogurt fermentation using lactose-free milk was slightly higher at 2 and 4 h of incubation, but reached 4.5 at the end of incubation, similar to that of the yogurt prepared from regular milk. The number of viable cells of Streptococcus thermophilus reached 108 CFU/mL after 2 h of incubation and increased to 109 CFU/mL after 4 h of incubation. During yogurt fermentation, the viable cells of Lactobacillus species and Bifidobacterium longum did not affect lactose hydrolysis. Although lactose-hydrolyzed milk did not promote the growth of starter cultures, manufacturing yogurt with lactose-free milk could be beneficial for the intestinal health of lactose-sensitive elderly.

• 한국식생활문화학회지
• /
• 제25권1호
• /
• pp.76-81
• /
• 2010

This study was conducted to evaluate the influence of Lactobacillus bulgaricus and/or Sterptococcus thermophilus on the fermentation of yoghurt containing 5% (w/v) buckwheat sprouts. The results revealed that after 12 hours of fermentation the appropriate pH, titratable acidity and number of viable cells were attained. At that time, the rutin content of the buckwheat sprout-added yoghurt prepared by the mixed culture method was not changed, but the quercetin content increased greatly. Conversely, the rutin content of yoghurt that only contained Streptococcus thermophilus was decreased while the quercetin content was increased. The total phenol contents as well as the DPPH radical scavenging activities of both the mixed culture and Streptococcus thermophilus yoghurt did not differ significantly. Taken together, the results revealed that the use of a mixed culture of Lactobacillus bulgaricus and Streptococcus thermophilus during the preparation of buchwheat sprout-added yoghurt was desirable due to the decrease in pH and increase in titratable acidity and viable cells that occurred after 12 hr of fermentation. Moreover, phytochemicals in buckwheat sprouts such as rutin, quercetin and phenol compounds were comparatively increased during fermentation and influenced the antioxidant activity in buckwheat sprout-added yoghurt.

• KSBB Journal
• /
• 제10권2호
• /
• pp.131-136
• /
• 1995

본 실험에서는 인간 전과립 세포를 회분배양 조건 에서 10%의 혈청을 포함하는 배지로 배양하였다. 이 와같은 조건에서 세포의 비성장율은 0.374C1/day) 이고 세포내 존재하는 살균활성을 가진 목적 단백질 의 생산성은 0.435(mg/10' viable cells)으로 나타났 다. 세포내 존재하는 목척 단백질의 순수 분리를 위 해 sephadex G-75, sephadex G-100, Bio→Rex70 을 이용해 분리하였다. 정제된 목적 단백질은 감수성 균주, E. coli IFO 13168과 St. aureus IFO 3060 을 표준 균주로 살균 측정을 하였을 때, 기존의 항생 물질은 균주에 대해 40~701땅1m!에서 활성을 나타 낸 반면, 정제된 목적 단백질은 G(+)균(St. aureus IFO 3060)에서는 $0.5\mu\textrm{g}$/ml이고, G(-)균(E. coli IFO 13168)에서는 $0.4\mu\textrm{g}$/ml에서 살균 활성을 보였다. 따라서 AMF가 기존 항생물질보다 살균 활성이 강력한 단백질임을 알 수 있다. 해당 분자량을 측정 하기 위해 SDS-PAGE로 측정한 결과 약 15,000 Dalton의 분자량을 갖고 있음이 확인됐다.

• 한국식품위생안전성학회지
• /
• 제12권3호
• /
• pp.175-180
• /
• 1997

Escherichia coli O157:H7 and Salmonella ser. typhimurium are pathogens involved in food poisoning in numerous countries. This study aimed to obtain knowleges on the survival of E. coli O157:H7 KSC 109 and S. ser. typhimurium ATCC 14028 in fermentedmilk products which were on sale in Suwon Yakult supplier. To the final concentration of 103~104 cfu/$m\ell$ of E. coli O157:H7 KSC 109 or S. wer. typhimurium ATCC 14028 in the fermented milks, Metchnikoff, Ace, Yakult, Mastoni and Super 100 were inoculated with these pathogens and then were stored at 4$^{\circ}C$ and viable cells of these pathogens were periodically counted. The results showed that the survival of two pathogens differed in the different types of fermented milks tested. Number of suriviving E. coli O157:H7 KSC 109 and S. ser. typimurium ATCC 14028 cells (initial inoculum, 103~104 cfu/$m\ell$) were decreased to 101, 102 cfu/$m\ell$ in Ace after 100 hours, and were decreased gradually to 101 cfu/$m\ell$ in Yakult after 250 hours. In the other fermented milks, viable cells of E. coli O157:H7 KSC 109 was not drastically decreased but those of S. ser. typhimurium ATCC 14028 was decreased gradually to 102 (Mastoni), and to 101 cfu/$m\ell$ (Super 100) after 250 hours. It appeared that S. ser. typhimurium ATCC 14028 was more susceptible than E. coli O157:H7 KSC 109 at low pH. Vibale cells of E. coli O157:H7 KSC 109 was not drastically decreased in most of fermented milks tested except Ace and Yakult, but in general, S. ser. typhimurium ATCC 14028 was drastically decreased in most of the fermented milks. The major ingibition factor against these pathogens in the fermented milks during storage at 4$^{\circ}C$ appeared to be the acidity and the metabolites produced by the starters bacteria used in fermented milk products.

• Nuclear Medicine and Molecular Imaging
• /
• 제41권5호
• /
• pp.364-372
• /
• 2007

목적 : 여러 종양영상용 방사성의약품이 암환자에서 치료후 반응을 보는 데 사용되고 있다. 이 연구에서는 paclitaxel 노출 시간에 따른 여러 종양영상용 방사성의약품의 유방암세포 섭취양상을 paclitaxel 노출 48시간까지 생존종양세포 수와 비교하여 알아보았다. 대상 및 방법 : F-18-fluorodeoxyglucose, C-11-methionine, Tl-201, Tc-99m-MIBI, Tc-99m-tetrofosmin의 5가지 종양영상용 방사성의약품의 MCF-7 유방암세포에서의 세포섭취를 알아보았다. DMSO 노출 대조군, 다양한 paclitaxel 노출시간을 가지는 5가지의 실험군(노출시간 2시간, 6시간, 12시간, 24시간, 48시간)의 총 6가지 조건에서 종양영상용 방사성의약품을 60분간 섭취시킨 뒤 섭취율을 구하였다. Paclitaxel은 10 nM과 100 nM의 2가지 농도를 사용하였다. 결과 : 10 nM의 paclitaxel은 노출 48시간까지 MCF-7 세포의 살아 있는 세포의 비율을 약 75% 정도로 감소시켰지만, 종양세포의 5가지 종양영상용 방사성의약품 섭취는 대조군과 비교시 유의하게 감소하지 않았다. 100 nM의 paclitaxel은 노출 48시간까지 MCF-7 세포의 살아 있는 세포의 비율을 약 55% 정도로 감소시켰지만, 종양세포의 5가지 종양영상용 방사성의약품 섭취는 대조군과 비교시 유의하게 증가하였다. 결론 : MCF-7 유방암세포주에서 종양영상용 방사성의약품인 F-18-FDG, C-11-methionine, Tl-201, Tc-99m-MIBI, Tc-99m-tetrofosmin의 섭취율은 paclitaxel 투여 후 48시간까지 생존 종양세포 수의 감소를 반영하지 못한다.

• Toxicological Research
• /
• 제15권1호
• /
• pp.47-53
• /
• 1999

The effects of methidathion on humoral immune response were studied in BALB/c mice. 0.5 or 5.0 mg/kg/day methidathion were administered orally for 14 days. The parameters examined to assess apparent toxicity of methidathion included changes of body weight, relative weight of spleen, thymus, sidney and liver, and viable spllenic cell numbers. To evaluate the humoral immune response, thymus, kidney and liver, and viable splenic cell numbers. To evaluate the humoral immune resopnse, the plaque forming cell(PFC) responses sheep the red blood cells (SRBC) and the lovels of serum IgG to hen egg lysozyme (HEL) were determined. No alterations were observed in changes of body weights, relative organ weights and the numbers of viable splenocytes by exposure to any dose of methidathion. At the dose of 0.5mg/kg only PFC response was decreased, whereas both PFC response and the level of serum IgG were decreased significantly at the dose of 5.0 mg/kg. These results indicate that exposure to methidathion may cause sup[pression of humoral immune reponse in mice without overt changed in lymphoid organ weight or viability of splenocytes.