• 한국유가공학회:학술대회논문집
• /
• 2005.10a
• /
• pp.11-19
• /
• 2005

Heat treatment is essential for hygienic safety and for extending shelf-life of milk. Heating of milk affects principally its physicochemical, nutritional and organoleptic properties. The most important changes are the decrease in whey protein solubility and the decrease in stability of casein micelles. Maillard reactions are also important and undesirable consequences.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.26 no.6
• /
• pp.1086-1090
• /
• 1997

Morphological properties on lintnerized maize starches with different amylose content were investigated. With increasing the lintnerization periods and decreasing the amylose content, hydrolysis rate was increased. As amylose content of starch was increased, the degree of damage with acid treatment was decreased by SEM. With increasing hydrolysis, iodine affinity, apparent amylose content and ${\lambda}_{max}$ of lintnerized starches were decreased. Water binding capacities of lintnerized starches were higher than those of native starches.

• Journal of Dairy Science and Biotechnology
• /
• v.38 no.3
• /
• pp.146-153
• /
• 2020

Recently, hyaluronic acid, which is the most popular among various biomaterials, has been used in osteoarthritis treatment, eye surgery, and wound healing. This study was carried out to determine the physicochemical and organoleptic properties of kefir containing various concentrations of hyaluronic acid. The pH value of hyaluronic-acid-containing kefir ranged from 3.58 to 3.46. Moreover, for hyaluronic-acid-containing kefir, the score of taste ranged from 4.75 to 4.0, the flavor ranged from 4.0 to 3.38, the color ranged from 4.38 to 4.0, the texture ranged from 4.38 to 3.75, and the overall acceptability ranged from 4.59 to 3.72. Overall, the organoleptic properties of hyaluronic-acid-containing kefir were better than those of the control. Because this is the first study involving hyaluronic acid and kefir, the results are valuable. The addition of hyaluronic acid did not significantly affect the physicochemical and organoleptic properties of kefir. Therefore, the commercial availability of various hyaluronic-acid-added dairy food products must be investigated.

• Journal of Animal Science and Technology
• /
• v.62 no.4
• /
• pp.577-586
• /
• 2020

This study was to investigate the effect of salt alone or in combination with phosphate on physicochemical and textural properties, and chemical interactions of low-fat model sausages. pH, color, expressible moisture (EM), cooking loss (CL), proximate analysis, textural profile analysis and low-vacuum scanning electron microscopy were performed. As salt content increased, color tended to decrease, as did EM and CL parameters, indicating that the ability to retain moisture was improved with increased salt levels (p < 0.05). In addition, textural hardness, gumminess and chewiness all increased with increasing salt (p < 0.05). Sausages with 0.3% salt showed the lowest cohesiveness compared to those with salt levels higher than 0.3% (p < 0.05). Addition of sodium tripolyphosphate (STPP) increased pH of sausages. Increasing salt and STPP did not affect lightness (p > 0.05), but did increase redness and yellowness (p < 0.05). The moisture content was higher when the salt and STPP contents were increased (p < 0.05), but no differences in the fat and protein contents (%) were observed (p > 0.05). EM and CL tended to decrease with increasing salt and STPP. In textural properties, the combination of 1.8% salt and 0.3% STPP was the best among other treatment (p < 0.05). Surface microstructure showed a flat and dense structure with increasing salt and STPP. Since the addition of salt and phosphate improved the functionality, textural and physicochemical properties of meat products in this study, meat products will need to be developed in line with consumer's preference.

• Microbiology and Biotechnology Letters
• /
• v.36 no.4
• /
• pp.285-290
• /
• 2008

Rahnella aquatilis strain AY2000 produces an anti-yeast substance (AYS), however activity of the AYS has a declining tendency during storage. To investigate what has been decreased activity of the AYS, the AYS was treated with various physicochemical agents in this paper. The activity of AYS was decreased by heat treatment. Thiol reagent such as $\beta$-mercaptoethanol or dithiothreitol was also another factor decreasing the activity of AYS. However, pH, EDTA, and NaCl were not factors decreasing the activity of AYS. Use of methanol to precipitate the AYS was also decreased the activity of AYS. The activity of AYS was not lost after Sepharose S-400 gel filtration. However, the AYS activity was completely lost, when a polysaccharide and a unknown substance (230 nm absorption) among components of the AYS was separated by DEAE-cellulose chromatography. MIC of the AYS against S. cerevisiae was usually determined at $7.8-15.6{\mu}g/ml$.

• Journal of Korea Foresty Energy
• /
• v.25 no.2
• /
• pp.55-63
• /
• 2006

Physicochemical properties and copper (II) adsorption ability of two oakwood and two pinewood charcoals, which were manufactured in traditional mode and commercialized in Korea, were examined pHs of these four wood charcoals were between 9.5 and 9.8. In the elemental contents of the wood charcoal, the contents of carbon atom (C) in the four samples were between 85-90%, while the content of hydrogen atom (H) in pinewood charcoal of the company 'S' was 1.62% and this value was three time higher than those of other samples. For iodine adsorption and specific surface area, the pinewood charcoal sample showed higher values than those of the oakwood charcoals. In the copper (II) ion adsorption in aqueous solution, the adsorption rate was increased by the increase of treated amounts of charcoal, treatment time, and pH.

• Food Science of Animal Resources
• /
• v.35 no.3
• /
• pp.322-329
• /
• 2015

This study investigated the effects of glucono-δ-lactone (GdL) addition on physicochemical and microbiological characteristics of fermented sausages during ripening and drying. Five batches of sausages were produced under ripening conditions: without GdL and with 0, 0.1, 0.25, 0.5 and 0.75% of GdL addition. Samples from each treatment were taken for physicochemical and microbiological analyses on the 0, 1, 3, 5, 7, 10, 15, 20 and 25th day of ripening. Chemical analysis showed a significant decrease in moisture content of sausages with increasing amounts of GdL added (p<0.05). The moisture contents decreased, whereas the fat, protein and ash contents increased throughout ripening (p<0.05). Increasing levels of GdL caused a decrease in the pH values (p<0.05), which can have an inhibitory effect against microflora. Water holding capacity content of samples decreased with increasing GdL concentration (p<0.05). The shear force values of fermented sausages showed the highest in T4 (p<0.05). During ripening, the shear force values of sausages were increased on the 25th day compared to day 0 (p<0.05). The higher GdL level produced lighter and more yellow sausages. The addition of 0.75% GdL was effective in controlling bacteria counts. Addition of GdL in sausages resulted in the physicochemical and microbiological attributes equal to or better than no addition of GdL without any harmful effect.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.40 no.8
• /
• pp.737-742
• /
• 2016

An elastomer (especially PDMS) sponge is considered to be a promising selective absorber in cleaning up oil spills. The performance of a PDMS sponge in capturing and separating oil from (sea) water depends on several parameters such as surface roughness, physicochemical treatments, and hydrostatic stability. Here, we first present a method of fabricating the PDMS sponges having numerous micro-sized pores that act as absorption and storage spaces for the target material, and then we report an experimental effort undertaken to control the surface physicochemistry (i.e., hydrophobicity or hydrophilicity) of the PDMS sponges by adjusting the size of the pores and the concentration of the surfactant (i.e., silwet L-77). From the experimental results, we develop an in-depth understanding of the mechanism for controlling the surface physicochemistry of PDMS using water-soluble micro-sized particles and a surfactant. The surface energy and absorbing behavior of the PDMS sponges are also extensively discussed.

• Asian-Australasian Journal of Animal Sciences
• /
• v.33 no.4
• /
• pp.662-669
• /
• 2020

Objective: This study was conducted to evaluate the effect of red glasswort (RG) (Salicornia herbacea L.) curing on the physicochemical, textural and sensory properties of cooked pork loin ham (M. longissimus thoracis et lumborum). Methods: All treatments were cured with different salt and RG powder levels. RG0 treatment was prepared with only 4% NaCl (w/w) as a control, and RG25, 3% NaCl:1% RG (w/w); RG50, 2% NaCl:2% RG (w/w); RG75, 1% NaCl:3% RG (w/w); RG100, 0% NaCl:4% RG (w/w) treatments were prepared sequentially. All samples were individually vacuum packaged in polyethylene bags and stored for 7 d at 3℃±1℃. Results: The results showed that as the rate of RG substitution increased, pH value, redness, myofibrillar protein solubility, and myofibrillar fragmentation index increased (p<0.05), but salt concentration and shear force decreased (p<0.05). However, there were no significant differences in cooking loss and moisture content. In terms of sensory evaluation, RG100 exhibited higher scores in tenderness and juiciness than RG0 (p<0.05). Conclusion: The partial substitution of NaCl by RG could improve the physicochemical properties, textural and sensory characteristics of cooked pork loin. Therefore, it is suggested that RG as a natural salt replacer could be an effective ingredient for developing low-sodium cured hams.

• Journal of environmental and Sanitary engineering
• /
• v.10 no.2
• /
• pp.36-45
• /
• 1995

Physicochemical environments and phytoplankton community in the nakdong river middle basin were investigated during a period of 1 year from Nov. 1993 to Oct. 1994. The ranges of Physicochemical environment factors in the nakdong river middle basin were $3.6~27.4{\circ}C$ for temperature, 7.1~9.3 for pH, $7.1~12.7mg/{\ell}$for DO, $0.7~2.1mg/{\ell}$ for BOD, $31~52mg/{\ell}$ for alkalinity, $2.101~3.3mg/{\ell}$ for T-N, $0.052~0.099mg/{\ell}$ for T-p, $5.4~92.3mg/m^{3}$ for chlorophyll-a. The number of Phytoplankton was lowest in Jan. that is, 244ce11s/ml and that was highest in Sep. 1201 cells/ml. The increase of dominant genera were correlated with the total nomber of phytoplanktons. Bacillariaceae, chlorophyceae, cyanophyceae, and euglenophlrceae were to 74.5%, 20%, 3.5%, and 2.2% respectively. Bacillariaceae were abundant during all the year round except for Jun, Jul, Aug. Chlorophyceae were plentiful in Jun, Jul, Aug. Tase-and odor-causing algae and filter clogging algae were 72% in Nov. and 93.5% in Jun. They were abundant all the year round except for winter, so they influenced on the treatment of tap water system. They belong to the general asterionella, cyclotella, melosira, nitzschia of bacillariaceae and actinastrum, pediastrum of chlorophyceae. Dominace index was low in winter and high in umber. Diversity index and equitability index were low in summer and high in winter. Therefore, the structure of phytoplankton community of the nakdong river middle basin was different form season to season.