• Title/Summary/Keyword: Physicochemical changes

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Emulsifying Properties of Bovine Lactoferrin in Food Emulsion System (식품 유화액 시스템에서 락토페린의 유화 특성)

  • Bae, Jae-Seok;Kim, Jeong-Won;Jeong, Yong-Seon;Lee, Eui-Seok;Hong, Soon-Taek
    • Journal of the Korean Applied Science and Technology
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    • v.30 no.4
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    • pp.779-789
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    • 2013
  • This study aimed to investigate the emulsifying properties of bovine lactoferrin in food emulsion system. First, lactoferrin solution was prepared to study its surface activities, such as surface adsorption characteristics and ${\zeta}$-potential. Second, some physicochemical properties of lactoferrin emulsion which resulted from variations of environmental conditions (i.e., pH or NaCl addition) were determined. As for surface adsorption characteristics evaluated by surface tension, it was decreased with increasing lactoferrin concentration in solution ($1{\times}10^{-5}{\rightarrow}0.2wt%$) and showed a plateau (${\fallingdotseq}44$mN/m) above 0.01 wt%. It was also changed with pH and the minimum value of 53.8 mM/m was observed at pI of lactoferrin. This was related to changes in ${\zeta}$-potential of the lactoferrin solution with respect to pH. Fat globule size of lactoferrin emulsion was decreased with increasing lactoferrin concentration and a stable emulsion was formed above 0.5 wt% lactoferrin in emulsion with fat globule size $d_{32}$ of ca. 0.33 ${\mu}m$ as confirmed by creaming stability experiment (i.e., Turbiscan). As with surface tension, fat globule size of lactoferrin emulsion also changed with pH and showed a maximum value at pI. As evaluated by Turbiscan, in the presence of NaCl, the lactoferrin emulsion showed instability in particular above 10 mM.

Microbiological Characteristics of Alcoholfermenting Wild Yeast, Aureobasidium pullulans P-1 and Its Makgeolli Fermentation Characteristics (알코올 발효성 야생 효모, Aureobasidium pullulans P-1의 균학적 특성과 막걸리 발효 특성)

  • Hong, Yong-Cheol;Han, Sang-Min;Lee, Jong-Soo
    • The Korean Journal of Mycology
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    • v.46 no.3
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    • pp.307-314
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    • 2018
  • The goal of this study was to investigate the microbiological characteristics of the ethanol-producing wild yeast, Aureobasidium pullulans P-1, isolated from flowers growing near the Yedang reservoir, Chungnam province, Korea, and in addition, to optimize its fermentation ability for the production of Makgeolli. A. pullulans P-1 was oval-shaped, and formed ascospores and pseudomycelium. The P-1 strain was a halophilic and sugar tolerant yeast which grew in 15% NaCl and 50% glucose-containing yeast extract-peptone-dextrose media. The P-1 strain was also resistant to 20% ethanol. Changes of the physicochemical properties during Makgeolli fermentation by A. pullulans P-1 were investigated. A maximum of 8.45% ethanol was obtained when a mixture of cooked rice, 150% water, and 35% ipguk per cooked rice was fermented by 5% A. pullulans P-1 culture broth at $25^{\circ}C$ for 10 days. Antihypertensive angiotensin I-converting enzyme inhibitory activity in the Makgeolli ferment produced by A. pullulans P-1 reached a high of 71.1% after 10 days.

Modification of Quality Characteristics of Onion Powder By Hot-air, Vacuum and Freeze Drying Methods (열풍, 진공 및 동결건조 양파분말의 품질특성)

  • Kang, Nan-Suk;Kim, Jun-Han;Kim, Jong-Kuk
    • Food Science and Preservation
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    • v.14 no.1
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    • pp.61-66
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    • 2007
  • This study investigated changes in physicochemical properties of onion powders during various drying conditions. The moisture content during vacuum drying at $40^{\circ}C$ remained at 5.23% for 5 days of drying, and it was possible to quickly obtain day powder Weight reduction upon $-70^{\circ}C$ vacuum drying was 90% after 7 days. The large change in browning caused by vacuum freeze drying was lowest ($OD_{420}\;of\;1.173$) after 7 days of drying. The content of vitamin C increased with vacuum freeze drying. The major free sugars were fructose, glucose and sucrose. Of organic acids, citric acid was prominent and, after vacuum freeze drying, showed a high value of 1,965 mg/100g. Free amino acids noted were L-arginine, ${\beta}-alanine$, L-alanine and L-threonine. In summary, vacuum freeze drying at $-70^{\circ}C$ is optimal.

Effect of Potassium Sorbate and Sodium Acid Pyrophosphate on Microbiological and Physicochemical Characteristics of Chicken (Potassium Sorbate와 Sodium Acid Pyrophosphate가 닭고기의 미생물과 이화학적 특성에 미치는 영향)

  • 김미라
    • Journal of the East Asian Society of Dietary Life
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    • v.6 no.2
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    • pp.187-194
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    • 1996
  • Changes of the growth of microorganisms, pH, and TBA values were examined for chickens treated with 5% potassium sorbate, 5% sodium acid pyrophosphate, and mixture of 2.5% potassium sorbate and 2.5% sodium acid pyrophosphate solution during 15 days at 4$^{\circ}C$. Treatment of the mixture solution inhibited synergistically the growth of mesophilic and psychrotrophic bacteria and suppressed effectively enteric bacilli. Potassium sorbate treatment was the most effective on inhibition of the growth of yeast and mold. The extension of lag phase for psychrotrophic bacteria and enteric bacilli was observed by the treatment of the mixture solution of potassium sorbate plus sodium acid pyrophosphate and the potassium sorbate solution. PHs of chickens were increased during the storage, which might induce the decline of antimicrobial effect. Sodium acid pyrophosphate was expected to give antioxidant effect as well as antimicrobial effect for high fat foods because the lowest increase of TBA value for chickens treated nth sodium acid pyrophosphate was measured.

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Changes in Adding Soybean on Quality and surface structure of Korean Rice Cake(Jeung-Pyun) (콩첨가에 따른 증편의 품질과 표면구조 변화)

  • 신광숙;우경자
    • Korean journal of food and cookery science
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    • v.15 no.3
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    • pp.249-257
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    • 1999
  • Jeung-Pyun is a traditional fermented Korean food with rice flour, water, sugar, salt and unrefined rice wine(Takju). In order to investigate how the addition of soybean has an influence on Jeung-Pyun fermentation, changing to adding amount of soybean 0%, 5%, l0%. 15%, 20% based on rice weight, we carried out sensory evaluation and measured the physicochemical properties, instrumental characteristics and degree of gelatinization. The specific volume of Jeung-Pyun was increased as the more soybean was added. The pH of Jeung-Pyun batter was decreased as the fermentation time was longer, but it was increased as more soybean was added. The degree of gelatinization of Jeung-Pyun was decreased as storage day was longer, but it was high as more soybean was added compared to control(0%). In sensory evaluation, Jeung-Pyun added 5∼10% of soybean was good generally. Correlation coefficient between hardness and degree of gelatinization was high. In instrumental characteristics, hardness was increased only in control for room temperature storage(20$^{\circ}C$), but at 4$^{\circ}C$ it was less increased than control(0%) as more soybean was added. Cohesiveness was decreased generally as storage day was longer at 4$^{\circ}C$, but it was less decreased as more soybean was added. In brittleness at 4$^{\circ}C$, Jeung-Pyun of adding soybean was higher compared to control. In surface structure of Jeung-Pyun observerd by SEM. air pore size was small and distributed regularly as more soybean added. In conclusion. it can be suggested that the addition of soybean improve the quality of Jeung-Pyun.

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Sensory and Physicochemical characteristics and Storage time of Daechu-Injeulmi added with various levels of jujube powder (대추가루를 첨가한 대추인절미의 관능적, 이화학적 특성과 저장성 연구)

  • 차경희;심영현;이효지
    • Korean journal of food and cookery science
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    • v.16 no.6
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    • pp.609-621
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    • 2000
  • The purpose of this study was to investigate the effect of addition of jujube on lnjeulmi in storage. Jujube powder was added to lnjeulmi made from the steamed glutinous rice, glutinous rice flour and brown glutinous rice flour. As a result of the sensory evaluation, the more jujube is added, the stronger sweetness and the more bitterness is shown. The sweetness and bitterness, made from brown glutinous rice, of Deachu-Injeulmi added jujube powder is the highest, and the more jujubes are tasted. Tenderness and moistness of Deachu-Injeulmi is decreased in the order of Deachu-Injeulmi made from glutinous rice, brown glutinous rice, glutinous rice flour, tenderness and moistness is increased with less amount of jujube. Chewiness of Deachu-Injeulmi made brown glutinous rice flour is the highest and Deachu-Injeulmi made from glutinous rice is the most rough. Moisture content is decreased in the order of Daechu-Injeulmi from glutinous rice, glutinous rice flour, brown glutinous rice flour. The reducing sugar content about storage period of Daechu-Injeulmi is decreased in the order of glutinous rice, glutinous rice flour, brown glutinous rice flour, and it is dramatically reduced until 48 hours of storage. However, it is increased a little bit after 72 hours. The changes in degree of gelatinization by storage period is that it is rapidly reduced until 24 hours, and it is decreased in the order of glutinous rice, glutinous rice flour, brown glutinous rice flour. That is to say, the more jujube powder is added, the less change there is. Springiness and cohesiveness is decreased during storage. Chewiness and gumminess is higher with more jujube, and it is increased until 24hour of storage period, then it is decreased after 48 hours. Hardness of Daechu-Injeulmi made from glutinous rice flour is the highest and the more jujube is added. Hardness of Daechu-Injeulmi added jujube powder is decreased in the order of Daechu-Injeulmi of 2.5%, 10% and 7.5%. The more jujube is added, the less change of the hardness by the storage period Daechu-Injeulmi is observed, thus the speed of the retrogradation is getting slower.

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Physicochemical Properties of Cheonggukjang with Fermentation Period for a Variety of Soybean Cultivars (콩 품종별 발효기간에 따른 청국장의 이화학적 특성)

  • Baek, Ji Eun;Choi, Yoon Hee;Song, Jin;Yun, Hong Tai;Choi, Hye Sun;Park, Shin Young
    • The Korean Journal of Food And Nutrition
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    • v.27 no.4
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    • pp.742-750
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    • 2014
  • This study was done in order to investigate the changes in quality of Cheonggukjang for soybean cultivars during fermentation. Cheonggukjang of 14 cultivars that were inoculated with Bacillus subtilis 15893 was produced, and, then, it was measured for hardness, proximate composition, amino nitrogen, enzyme activity, and total aerobic bacteria counts. In a raw bean, the highest hardness value was 16,975 g from Sunyu. In a steaming bean, Jangwon had the highest hardness value and the lowest aerobic bacteria counts of forty-eight hours fermented Cheonggukjang. Saedanbaek, whose protein contents was highest in raw bean, was also highest in Cheonggukjang. The amino nitrogen content of twenty-four hours fermented Cheonggukjang was highest in Saeol and Sunyu while forty-eight hours fermented Cheonggukjang was highest in Singi, Daol, and Milyang 231. In the protease activity, Saedanbaek had the highest and total aerobic bacteria count that were either increased or held as time went on ; twenty-four hours fermented Cheonggukjang was highest in Milyang 231 and Keunol while forty-eight hours fermented Cheonggukjang was highest in Chunsang.

Recent advances in the characterization and the treatment methods of effluent organic matter

  • Ray, Schindra Kumar;Truong, Hai Bang;Arshad, Zeshan;Shin, Hyun Sang;Hur, Jin
    • Membrane and Water Treatment
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    • v.11 no.4
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    • pp.257-274
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    • 2020
  • There are many previous review articles are available to summarize either the characterization methods of effluent organic matter (EfOM) or the individual control treatment options. However, there has been no attempt made to compare in parallel the physicochemical treatment options that target the removal of EfOM from biological treatments. This review deals with the recent progress on the characterization of EfOM and the novel technologies developed for EfOM treatment. Based on the publications after 2010, the advantages and the limitations of several popularly used analytical tools are discussed for EfOM characterization, which include UV-visible and fluorescence spectroscopy, Fourier transform infrared spectroscopy (FTIR), size exclusion chromatography (SEC), and Fourier transform-ion cyclotron resonance-mass spectrometry (FT-ICR-MS). It is a recent trend to combine an SEC system with various types of detectors, because it can successfully track the chemical/functional composition of EfOM, which varies across a continuum of different molecular sizes. FT-ICR-MS is the most powerful tool to detect EfOM at molecular levels. However, it is noted that this method has rarely been utilized to understand the changes of EfOM in pre-treatment or post-treatment systems. Although membrane filtration is still the preferred method to treat EfOM before its discharge due to its high separation selectivity, the minimum requirements for additional chemicals, the ease of scaling up, and the continuous operation, recent advances in ion exchange and advanced oxidation processes are greatly noteworthy. Recent progress in the non-membrane technologies, which are based on novel materials, are expected to enhance the removal efficiency of EfOM and even make it feasible to selectively remove undesirable fractions/compounds from bulk EfOM.

Development and Basic Performance Characterization of Neutralized Fabric Filter (제전사여과포의 개발 및 기초성능 규명)

  • 박영옥;구철오;임정환;김홍룡;손재익;이영우
    • Journal of Energy Engineering
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    • v.7 no.1
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    • pp.57-64
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    • 1998
  • A neutralized fabric filter of which major raw materials were polyester and stainless steel fibers was developed and its physiochemical properties and basic filter characteristics were investigated. Four finds of dusts generated in the typical domestic industry were used, which were coke dust from a steel manufacturing process, cement dust from a cement manufacturing process, flu ash from a fluidized-bed combustor, and incinerator ash from a waste plastics incinerator. The physicochemical properties of the neutralized fabric filter were analyzed in terms of changes in tensile strength and initial elastic modulus under $SO_2$ and $NO_2$ atmospheres, mean flow pore pressure, bubble point pore diameter, mean flow pore diameter, and pore size distribution. In addition, the pressure drop, dust penetration, and figure of merit for the fabric filter were investigated in a bench-scale filter testing unit. The pressure drop increased as the filtration velocity and dust loading increased, and its increasing shape depended on the type of dust. The dust penetration rapidly decreased as the dust loading increased irrespective of the type of dust. The figures of merit for the fabric filters increased in the early stage of filtration and then showed rapid decreases followed maintaining a constant level.

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Functionality Changes of Rapeseed Protein upon Proteolysis (유채단백질의 Proteolysis에 의한 기능성 변화)

  • Kim, Chung-Hee;Kim, Hyo-Sun;Lee, Jang-Soon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.21 no.5
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    • pp.519-524
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    • 1992
  • purified rapeseed(Brassica napus var. Youngsan) protein was hydrolyzed by pronase. The hyrolysate protein was investigated for the some physicochemical and functional properties. UV and intrinsic fluorescence spectra of the hydrolysate showed the maximum absorption at 274nm and 360nm respectively. Intensity of yellow color decreased in the process of hydrolysis and the surface hydrophobicity decreased up to fourfold. The main bands of hydrolysate by sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE) were observed at 14,000 to 12,000 dalton molecular weight. Solubilities of hydrolyzed protein increased by 10~15% compared to those of unhydrolyzed protein at acidic pH. In the hydrolysate, while absorption of both water and oil, foam expansion and emulsion stability were increased, absolute viscosity, heat coagulation, calcium coagulation, foam stability and emulsion activity were decreased.

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