• Asian-Australasian Journal of Animal Sciences
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• v.33 no.2
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• pp.323-331
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• 2020

Objective: The present work was undertaken to determine the possibility of using xanthan and guar gums as stabilizers to enhance the yogurt quality. Methods: Yogurt was manufactured from standardized milk (3.5% fat, 8.5% solid-not-fat contents) with the addition of 2% to 3% starter culture. Enzyme-hydrolyzed xanthan gum (0.1%, 0.5%, 1.0%) and guar gum (0.1%, 0.5%, 1.0%) were added to the yogurt as stabilizers. Prepared yogurt samples were kept at refrigeration temperature (4℃±2℃) for 21 days and various quality and sensory parameters were studied at regular intervals (7 days). Results: Results showed that yogurt with 0.5% xanthan gum (T5) was best in terms of preventing syneresis and improving the viscosity, water holding capacity and texture of the product. Additionally, adding gums did not adversely affect the sensorial attributes of the product. Conclusion: Modified gums were found useful in augmenting yogurt quality and therefore addition of gums is highly recommended for manufacturing yogurt.

• Journal of the Korean Home Economics Association
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• v.17 no.4
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• pp.35-42
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• 1979

The effects of salt concentration on the qualities of cooked egg preparations were evaluated. Diluted egg samples which contained different amounts of slat were prepared by diluting whole egg fluid with rice washing, anchovy stock , or distilled water. After heating them rapidly, hardness, gel strength, and amount of syneresis were determined along with the performance of sensory test. the pH of the diluted eggs also measured before heating. Results obtained from these experiments are summarized in the following. 1. The pH of whole egg, egg yolk, and egg white was 7.32, 6.31, and 8.41 , respectively. 2. The pH whole eggs after addition of diluting solutions and salt showed a little differences over the whole salt concentration as follows. distilled water dilution > anchovy stock dilution > rice washing dilution 3. The hardness and gel strength of cooked samples were increased with the increase of salt concentration in the range of low salt concentrations of all diluting solution. These physical properties marked maximal values at salt concentration of 3% and then decreased as salt concentration increased. 4. Amount of syneresis decreased as salt concentration increased regardless of all diluting solutions used. 5. In sensory test, 1% salt concentration were scored good by the panel members regardless of diluting solutions which showed no significant difference among three diluting solutions.

• Food Science of Animal Resources
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• v.37 no.4
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• pp.606-616
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• 2017

The objective of this research was to investigate the effects microbial transglutaminase (mTGs) on the physicochemical, microbial and sensory properties of kefir produced by using mix cow and soymilk. Kefir batches were prepared using 0, 0.5, 1 and 1.5 Units m-TGs for per g of milk protein. Adding m-TGs to milk caused an increase in the pH and viscosity and caused a decrease in titratable acidity and syneresis in the kefir samples. Total bacteria, lactobacilli and streptococci counts decreased, while yeast counts increased in all the samples during storage. Alcohols and acids compounds have increased in all the samples except in the control samples, while carbonyl compounds have decreased in all the samples during storage (1-30 d). The differences in the percentage of alcohols, carbonyl compounds and acids in total volatiles on the 1st and the 30th d of storage were observed at 8.47-23.52%, 6.94-25.46% and 59.64-63.69%, respectively. The consumer evaluation of the kefir samples showed that greater levels of acceptability were found for samples which had been added 1.5 U m-TGs for per g of milk protein.

• Korean Journal of Food Science and Technology
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• v.24 no.1
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• pp.42-48
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• 1992

The rate and extent of coagulation of milk using fast acidification with 0.1 N HCl were monitored by changes in viscosity and turbidity at various temperatures and pH. Also the gelation rate of milk using slow acidification with D-glucono-${\delta}$-lactone was measured in a small strain rheological scanner. Coagulation of milk casein occurred in a specific pH range and was accompanied by an abrupt increase in viscosity at pH 5.0. Acid coagulation rate was enhanced by increasing temperature from $20^{\circ}C{\sim}50^{\circ}C$, and the maximum rate was shown around pH 5.0. The addition of salt ($CaCl_{2}$) reduced the maximum coagulation rate at all temperature ranges and shifted the pH ranges for maximum coagulation rate and the onset pH of coagulation. The onset of gelation and the rate of network formation during slow acidification were facilitated by Cl ion, but suppressed by SCN-ion, as indicated by the rate of rigidity development. The susceptibility to syneresis was greater in the gel made at lower temperature and around pH 4.6, while preheated milk at $90^{\circ}C$ for 5 min prior to acidification showed the same syneresis profile at all heating temperatures ($60{\sim}90^{\circ}C$).

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.8
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• pp.1168-1175
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• 2012

Gel properties of Mook manufactured from acorn harvested in various countries [domestic (KAS), Chinese (CAS), and North Korea (NAS)] were analyzed according to storage period. Gel properties included water binding, syneresis of gel, DSC (differential scanning calorimetry), X-ray diffraction, SEM (scanning electron microscopy), texture, Hunter's color value, and sensory value. Water binding of NAS, CAS, and KAS were 233.8%, 217.3%, and 215.0%, respectively. Syneresis of gel from KAS, CAS, and NAS were 2.06%, 1.85%, and 1.45%, respectively, after 1 day of storage. There were significant differences upon storage for 1~3 days (p<0.05), whereas were no significant differences upon storage for 4~10 days. Peak temperature of gelatinization property by DSC was $55.28^{\circ}C$ for KAS, $54.45^{\circ}C$ for CAS, and $54.12^{\circ}C$ for NAS after 1 day of storage. Hardness of texture in NAS, KAS, and CAS were 374.9, 357.4, and 348.9, respectively, after 1 day of storage. Hunter's color L value, and a value were highest in NAS, whereas b value was the lowest in CAS. There were no significant differences in any particular sensory values.

• Food Science of Animal Resources
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• v.25 no.1
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• pp.84-91
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• 2005

We investigated fermentation characteristics and the amount of exopolysaccharide (EPS) produced, and the correlation between EPS and rheological properties in stirred yogurt fermented with Streptococcus thermophilus St-Body 1. The changes of pH and lactic acid concentrations of yogurt showed different patterns according to fermentation temperatures. About 20 to 40% of lactose was utilized during 6 hrs incubation. The higher number of lactic acid bacteria was obtained at 31℃ incubation temperature rather than other incubation temperatures. The higher amount of EPS was produced at 12 hr or 24 hr rather than other incubation period at the same fermentation temperatures. The viscosity continuously increased during the fermentation period, however the syneresis of yogurt was shown the lowest value at 37℃ for 30 hrs incubation. In physical properties, the hardness and adhesiveness increased continuously with decreasing cohesiveness and elasticity as incubation process was extended. The stirred yogurt fermented with S. thermophilus St-Body 1 at 37℃ for 24 hr resulted in the highest score at each sensory evaluation category.

• Animal Bioscience
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• v.35 no.2
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• pp.281-289
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• 2022

Objective: The aim of this study was to characterize the exopolysaccharides (EPS)-producing lactic acid bacteria from Taiwanese ropy fermented milk (TRFM) for developing a clean label low-fat fermented milk. Methods: Potential isolates from TRFM were selected based on the Gram staining test and observation of turbid suspension in the culture broth. Random amplified polymorphic DNA-polymerase chain reaction, 16S rRNA gene sequencing, and API CHL 50 test were used for strain identification. After evaluation of EPS concentration, target strains were introduced to low-fat milk fermentation for 24 h. Fermentation characters were checked: pH value, acidity, viable count, syneresis, and viscosity. Sensory evaluation of fermented products was carried out by 30 volunteers, while the storage test was performed for 21 days at 4℃. Results: Two EPS-producing strains (APL15 and APL16) were isolated from TRFM and identified as Lactococcus (Lc.) lactis subsp. cremoris. Their EPS concentrations in glucose and lactose media were higher than other published strains of Lc. lactis subsp. cremoris. Low-fat fermented milk separately prepared with APL15 and APL16 reached pH 4.3 and acidity 0.8% with a viable count of 9 log colony-forming units/mL. The physical properties of both products were superior to the control yogurt, showing significant improvements in syneresis and viscosity (p<0.05). Our low-fat products had appropriate sensory scores in appearance and texture according to sensory evaluation. Although decreasing viable cells of strains during the 21-day storage test, low-fat fermented milk made by APL15 exhibited stable physicochemical properties, including pH value, acidity, syneresis and sufficient viable cells throughout the storage period. Conclusion: This study demonstrated that Lc. lactis subsp. cremoris APL15 isolated from TRFM had good fermentation abilities to produce low-fat fermented milk. These data indicate that EPS-producing lactic acid bacteria have great potential to act as natural food stabilizers for low-fat fermented milk.

• Food Science and Biotechnology
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• v.16 no.5
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• pp.663-674
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• 2007

Starches from different botanical sources differ in the ratio of amylose to amylopectin contents, molecular structures of amylose and amylopectin, granule morphology, and minor-component contents. These structural features result in different gelatinization, pasting, retrogradation properties, and enzyme digestibility of starch granules. In this review, compositions and molecular structures of starches and their effects on the physicochemical properties are summarized and discussed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.1
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• pp.70-74
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• 2000

Agar for microbiological medium was prepared with pilot-scale for industrial application by the process of microfiltration ($0.4 {\mu}m\;pore size$) in $40{\~}50{\circ}C$, washing with sot water, and treatment with $0.25\;N NaOH\;at\;70{\circ}C$. Transparency, gel strength, viscosity, sulfate content, and syneresis ratio of agar prepared from Gelidium amansii was compared with commercial agar for microbiological medium. Gel strength and transparency were increased with processing, however, it's viscosity, sulfate content, and syneresis ratio were reduced. The final agar product was superior to commercial agar for microbiological medium.

• Korean journal of food and cookery science
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• v.17 no.6
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• pp.598-603
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• 2001

Gel characteristics of potato starches which were prepared by steeping potato at 10$\pm$ 1$\^{C}$ and 25$\^{C}$$\pm$1$\^{C}$ incubator for 11days were investigated. Results of the instrumental test of potato starch gels showed significantly different strength, hardness, gumminess, chewiness, cohesiveness by steeping time. The light microscope and scanning electron microscope of starch gels showed three-dimensional network including macroporous structure by steeping. The syneresis of potato starch gel was decreased by steeping potato at 24 for 72 hours.