• Title/Summary/Keyword: pH buffering capacity

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pH and buffering capacity in some commercial fermented milks (일부 시판 유산균 발효유의 pH와 적정산도)

  • Ko, Seok-Ju;Jeong, Seong-Soog;Choi, Choong-Ho;Kim, Kyung-Hee
    • Journal of Korean society of Dental Hygiene
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    • v.13 no.4
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    • pp.701-711
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    • 2013
  • Objectives : The aim of this study was to evaluate the pH and buffering capacity in some commercial fermented milks in Korea. Methods : The study was carried ouf from June to August, 2012. In 35 liquid type, 79 condense-stirred type and 71 condense-drink type fermented milks, available on the market, pH and buffering capacity were measured. Titration(with NaOH) was used to determine the buffering effect of each fermented milk. They were titrated with 1 M sodium hydroxide, added in 0.1 milliliters increments, until the pH reached about 5.5 and 7.0. Results : The average pH of tested fermented milks was $4.08{\pm}0.27$. The average pH values of fermented milks were $3.64{\pm}0.22$ in liquid type, $4.14{\pm}0.12$ in condense-stirred type, and $4.22{\pm}0.17$ condense-drink type. The average buffering capacity (pH 5.5) of tested fermented milk was $2.40{\pm}0.54$. The average buffering capacity (pH 5.5) of liquid type fermented milk was $2.37{\pm}0.33$, condense-stirred type fermented milk was $2.77{\pm}0.46$ and condense-drink type fermented milk was $2.01{\pm}0.42$. The average buffering capacity (pH 7.0) of tested fermented milks was $4.00{\pm}0.87$. The average buffering capacity (pH 7.0) of liquid type fermented milk was $3.11{\pm}0.36$, condense-stirred type fermented milk was $4.78{\pm}0.55$ and condense-drink type fermented milk was $3.58{\pm}0.59$. Conclusions : The average pH of tested fermented milks in this study was lower than pH 4.5. The type of fermented milks was an important factor for selection of fermented milk which is related with enamel erosion.

Effect of Simulated Acid Solution on Acid Buffering Capacity, Chlorophyll Content and Nutrient Leaching in the Leaves fo 4 Herb Species (4종 촤화류에 대한 pH 수준별 처리가 잎의 완충능력, chlorophyll 함량 및 무기성분 용출에 미치는 영향)

  • 김학윤
    • Journal of Life Science
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    • v.11 no.3
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    • pp.197-202
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    • 2001
  • This study was conducted to investigate the effect of simulated acid solution(SAS) on acid buffering capacity, chlorophyll content and butrient leacking in 4 herb species(Petunia hybrida Vilm, Gomphrena globosa L. Celosia cristat L. Salvia officinallis L) . The acid buffering capacity in the leves was increased in the treatment of pH 3.0 in Celosia L., whereas it was increased at pH 4.0 in Petunia Petunia hybrida Vilm. and Gomprean globosa L.. But, the acid buffering capacity of the leaves did not work at ph 2.0 treatment in 4 herb species. With decreasing pH level, the chlorophyll content of Petunia hybrida Vilm. and Gomphrena globosa L. Was markedly decreased than that of Gelosia cristata L. and Savia officinalis L. As the pH levels decreased from 5.6 to 2.0 the nutrient leaching from leaves was significantly increased in 4 herb species. In pH 4.0 and 5.6, the concentrations of nutrient leaching from leaves were higher in Perunia hybrida Vilm. and Gomphrean globosa L. than Gelosia cristata L. and Salvia officinalis L., Based on the results, there was a great differences in response to SAS among the 4 herb species. Im general, Gelosia cristata L. and Salvia officinalis L. represented a higher tolerance to SAS Petunia hybrida Vilm, and Gomphrena globosa L..

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Relationship between saliva factors and oral hygiene factors in adults (일부 성인의 타액요인과 구강환경 요인의 관련성)

  • Hong, Min-Hee
    • Journal of Korean society of Dental Hygiene
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    • v.15 no.2
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    • pp.189-196
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    • 2015
  • Objectives: The purpose of the study is to investigate the relationship between saliva factors and oral hygiene factors in adults. Methods: The subjects were 112 adults from April 1 to June 15, 2014. The selected salivary factors included stimulated/unstimulated salivary flow rates, salivary buffering capacity and pH, and the selected oral hygiene factors included halitosis, wet weight of tongue plaque and oral humidity in dorsum and inferior surface of tongue. Results: There were significant differences in stimulated/unstimulated salivary flow rates, oral malodor and wet weight of tongue plaque. There were significant differences according to age in stimulated/unstimulated salivary flow rates, salivary buffering capacity and wet weight of tongue plaque. Age had a negative correlation with salivary buffering capacity and had a positive correlation with wet weight of tongue plaque. Unstimulated salivary flow rate had a positive correlation with stimulated salivary flow rate, and stimulated salivary flow rate was positively correlated with oral humidity of inferior surface of tongue, salivary buffering capacity and halitosis. Oral humidity of inferior surface of tongue had a positive correlation with salivary buffering rate, pH and halitosis. Salivary buffering capacity was positively correlated with pH, and pH was negatively correlated with halitosis. Conclusions: The salivary factors were linked to the oral hygiene. As there may be great changes in salivary flow rate and oral hygiene due to various factors, the salivary factors seem to be one of the major factors to ensure oral hygiene and to promote oral health.

Effect of Simulated Acid Rain on Germination, Growth, Acid Buffering Capacity and Nutrient Leaching in Impatiens balsamina L. and Tagetes patula L. (산성비가 봉선화(Impatiens balsamina L.) 및 만수국(Tagetes patula L.)의 발아, 생장, 완충능력 및 양료용탈에 미치는 영향)

  • 김학윤;이인중;신동현;김길웅;조문수
    • Journal of Life Science
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    • v.10 no.6
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    • pp.598-604
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    • 2000
  • This study was conducted to investigate the effect of simulated acid rain (SAR) on germination, growth, acid buffering capacity and nutrient leaching in Impatiens balsamina L. and Tagetes patula L.. In both species, germination was not inhibited at pH 4.0, but the germination rate decreased at the lower pH of 3.0, showing higher rate in Inpatiens balsamina L. than Tagetes patula L.. As the pH decreases, the growth of radicle was markedly decreased than that of hypocotyl in both species. The plant height, root length, leaf area, total dry weight, relative growth rate and net assimilation rate were inhibited by SAR. The acid buffering capacity in the leaves were increased at pH 4.0, on the other hand, it was shown a tendency to decrease at pH 2.0 in both species. As the pH levels decreased from 5.6 to 2.0, the nutrient leaching from leaves was significantly increased in both species. Based on the results, there are a great difference in the responses to SAR between the two species. In general, Tagetes patula L. represented a higher tolerance to SAR than Impatiens balsamina L.. These results suggested that interspecific variation in the acid buffering capacity and nutrient leaching from leaves may be responsible for the interspecific susceptibility to SAR.

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Effects of Fiber Sources on Ruminal pH, Buffering Capacity and Digestibility in Sheep (섬유소 공급원이 면양의 반추위 pH, Buffering Capacity 및 소화율에 미치는 영향)

  • Seo, In-Jun;Kim, Myeong-Hwa;Kim, Dong-Sik;Lee, Sang-Rak;Maeng, Won-Jai
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.25 no.3
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    • pp.177-184
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    • 2005
  • This study was conducted to study the effect of fiber sources on ruminal pH and buffering capacity and whole digestive tract digestibility with five ruminally fistulated sheep. Evaluated fiber sources were alfalfa hay cube (AHC), corn cob (CC), com silage (CS), cotton seed hull (CSH), peanut hull (PHL), rice straw (RS), and sugarcane bagasse (SCB). Sheep were fed consecutively a diet containing each tested fiber source $(45\%)$ with a corn-based concentrate diets $(55\%)$ during each experimental period. Ruminal pH showed no difference among fiber sources except the significantly lower pH at 8h (p<0.05) with RS (pH; 5.78) than those in other sources. Buffering capacity showed significant differences at 0h (p<0.05) and 2h (p<0.05) after feeding in CS compared to those from SCB and CC, while there was higher in PHL (p<0.01) at 12h post feeding except AHC than CC, CS, SCB, and RS. Dry matter digestibility was significantly higher in CS (p<0.001) than in other sources. Neutral detergent fiber digestibility was higher in CC, CS, CSH, and RS than other fiber sources (p<0.001). These results suggest that ruminal pH and buffering capacity and whole digestive track digestibility were significantly affected by fiber sources in ruminant diet, and, therefore, should be took those effects into account for TMR formulation.

Buffering Capacity of Dairy Powders and Their Effect on Yoghurt Quality

  • Kim, Miji;Oh, Sejong;Imm, Jee-Young
    • Food Science of Animal Resources
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    • v.38 no.2
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    • pp.273-281
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    • 2018
  • Preheating conditions (low-, medium-, and high heat-) did not significantly affect the buffering capacity (BC) of skim milk powder (SMP), whereas the level of demineralization significantly affected the BC of whey powders (WP). Heat treatment ($85^{\circ}C$ for 30 min) of both SMP and WP (90% demineralized) mixtures (88:12, 76:24, 64:36 and 52:48; SMP:WP) resulted in a reduced BC, and the extent of this reduction increased with the proportion of WP increased in the samples. High-buffering milk prepared by the addition of phosphate salts (40 mM $NaH_2PO_4$ and 60 mM $Na_2HPO_4$) delayed the rate of pH decline during yoghurt fermentation. The high-buffering yoghurt showed a significantly higher water holding capacity (WHC) than that of control yoghurt (p<0.05), as well as a more uniform and interconnected microstructure with small pore sizes than those of control yoghurt. No significant differences were found between high-buffering and control yoghurt regarding the viable bacterial counts of starter. The manipulation BC can potentially improve the quality characteristics of yoghurts, such as WHC and texture.

Physical and Chemical Properties of Soluble Sodium Silicate (수용성 규산나트륨의 물리 · 화학적 특성)

  • Ha, Youn Shick;Park, Kyeong Il;Seo, Moo Lyong
    • Journal of the Korean Chemical Society
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    • v.43 no.2
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    • pp.172-181
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    • 1999
  • To develop the manufacturing technique for the powder builder of amorphous solid types, the water glass mixed with caustic soda dispersed into the methanol. Thus soluble sodium silicate was made a form of amorphous solid powder. In order to examine characteristics of water soluble sodium silicate $SiO_2/Na_2O$ mol ratio, we investigated solubility, thermogram, SEM, and BET analysis. pH buffering capacity, calcium-ion binding capacity as temperature change, and surfactant loading capacity were examined for characteristics as laundry detergent builder. $SiO_2/Na_2O$ molar ratio of soluble sodium silicate was 1.0, 2.4, 2.8, and zeolite was used in order to investigate basic characteristics of laundry detergent builder. Silicate used with laundry detergent was good for pH buffering capacity and solubility. But calcium-ion binding capacity and surfactant adsorption ability were lower. $SiO_2/Na_2O$ mol ratio became higher, pH buffering capacity and ion exchange ability were lower and surfactant adsorption ability was a little higher.

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Effects of Species on the Isocyanate-bonded Flakeboard Properties

  • Kwon, Jin Heon
    • Journal of the Korean Wood Science and Technology
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    • v.35 no.5
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    • pp.38-45
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    • 2007
  • Flakeboards made from ring- and drum-cut flakes of Douglas-fir, hemlock, red lauan and kapur using two kinds of resin levels were evaluated for the selected properties according to flake thickness. The pH and buffering capacity of four species were determined. Those of kapur were extremely different from the other three species. These pH and buffering capacity values result in the poor internal bond strength of kapur flakeboard. The internal bond strength was affected significantly by flake thickness, resin content and species. MOR and MOE in bending strength were maximized at medium drum-cut flake thickness. Screw holding strength was not consistent for flake thickness, but it was influenced by species. Thickness swelling and water absorption of Douglas-fir and hemlock flakeboard were minimized at medium drum-cut flake thickness.

Detergency of Soluble Sodium Silicate (수용성 규산나트륨의 세정성)

  • Ha, Youn-Shick;Park, Kyeong-Il;Seo, Moo-Lyong
    • Analytical Science and Technology
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    • v.12 no.1
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    • pp.13-21
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    • 1999
  • Silicate used as laundry detergent builder was good for pH buffering capacity and solubility but calcium-ion binding capacity and surfactant adsorption ability were lower. As $SiO_2/Na_2O$ molar ratio became higher, pH buffering capacity and ion exchange ability were lower and surfactant adsorption ability was little higher. Anionic surfactant LAS (linear alkylbenzene sulphonate), nonionic surfactant LA-9 (lauryl alcohol EO-9) were used to investigate the detergency performance. Zeolite was better than sodium silicate in detergency performance. In case of LAS, detergency performance was good when $SiO_2/Na_2O$ molar ratio was lower. In case of LA-9, detergency performance was similar without discrimination of molar ratio of $SiO_2/Na_2O$.

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Chloride Threshold Value for Steel Corrosion considering Chemical Properties of Concrete (콘크리트의 화학적 특성을 고려한 철근 부식 임계 염소이온 농도)

  • Song, Ha-Won;Jung, Min-Sun;Ann, Ki Yong;Lee, Chang-Hong
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.1A
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    • pp.75-84
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    • 2009
  • The present study assesses the chloride threshold level for corrosion of steel in concrete by examining the properties of four different binders used for blended concrete in terms of chloride binding, buffering of cement matrix to a pH fall and the corrosion behaviour. As binders, ordinary Portland cement (OPC), 30% pulverised fuel ash (PFA), 60% ground granulated blast furnace slag (GGBS) and 10% silica fume (SF) were used in a concrete mix. Testing for chloride binding was carried out using the water extraction method, the buffering of cement matrix was assessed by measuring the resistance to an artificial acidification of nitric acid, and the corrosion rate of steel in mortar with chlorides in cast was measured at 28 days using an anodic polarisation technique. Results show that the chloride binding capacity was much affected by $C_{3}A$ content and physical adsorption, and its order was 60% GGBS>30% PFA>OPC>10% SF. The buffering of cement matrix to a pH fall was varied with binder type and given values of the pH. From the result of corrosion test, it was found that the chloride threshold ranged 1.03, 0.65, 0.45 and 0.98% by weight of cement for OPC, 30% PFA, 60% GGBS and 10% SF respectively, assuming that corrosion starts at the corrosion rate of $0.1-0.2{\mu}A/cm^{2}$. The mole ratio of [$Cl^{-}$]:[$H^{+}$], as a new presentation of the chloride threshold, indicated the value of 0.008-0.009, irrespective of binder, which would be indicative of the inhibitive characteristic of binder.