• Food Science and Biotechnology
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• v.18 no.2
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• pp.299-306
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• 2009

The purpose of this study was to prepare stable water-in-corn oil (W/O) emulsion droplets coated by polyglycerol polyricinoleate (PGPR). W/O emulsions (20 wt% aqueous phase, 80 wt% oil phase containing 8 wt% PGPR) were produced by high pressure homogenization (Emulsions 1), however, appreciable amount of relatively large water droplets (d>$10{\mu}m$) were found. To facilitate droplet disruption, viscosity of each phase was adjusted: (i) increased the viscosity of aqueous phase by adding 0.1 wt% xanthan (Emulsions 2); (ii) decreased the viscosity of oil phase and aqueous phase by heating them separately at $50^{\circ}C$ for 1 hr immediately before emulsification (Emulsions 3). Homogenizing at the elevated temperature clearly led to a smaller water droplet size, whereas xanthan neither improved nor adversely affected on the microstructures of the emulsions. In addition, the Emulsions 3 had good stability to droplet aggregation under shearing stress, thermal processing, and long term storage.

• Culinary science and hospitality research
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• v.10 no.1
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• pp.186-202
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• 2004

The purpose of this study was to find out the efficiency of control plan for the productivity at the deluxe hotel. To analyze the data, 5-point measure, self entry, SPSS, frequency analysis, difference analysis, many fold regression analysis. The results of this study could be explained as follow: change of occupation rate, reflect to employees, lack of stability a state of mind condition, reflected mental factor and stability of organization, and compared to the job satisfaction and inclination of a change of occupation.

• Food Science and Biotechnology
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• v.18 no.3
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• pp.610-617
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• 2009

The stability of corn oil-in-water emulsions coated by milk proteins, sodium caseinate (CAS), or whey protein concentrate (WPC), was compared under the environmental stress of pH change. Emulsions were prepared at 0.1 of protein:oil because the majority of droplets were relatively small ($d_{32}=0.34$ and $0.35\;{\mu}m$, $d_{43}=0.65$ and $0.37\;{\mu}m$ for CAS- and WPC-emulsions, respectively) and there was no evidence of depletion flocculation. As the pH of the emulsions was gradually dropped from 7 to 3, there was no significant difference in the electrical charges of the emulsion droplets between the 2 types of emulsions. However, laser diffraction measurements, microscopy measurements, and creaming stability test indicated that WPC-emulsions were more stable to droplet aggregation than CAS-emulsions under the same circumstance of pH change. It implies that factors other than electrostatic repulsion should contribute to the different magnitude of response to pH change.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.7
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• pp.1086-1095
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• 2013

This study investigated the quality characteristics, oxidative stability, and antioxidative activity of a Korean fried rice cake, Gaeseong-Juak (doughnut of waxy rice) to which Prunus yedoensis Matsumura (PYM) extract, vitamin C, and BHT were added and stored at $60^{\circ}C$ for 4 days. Gaeseong-Juak was prepared by adding PYM extract at 0, 0.5, 1, and 2% of waxy rice powder. It was found that as the content of PYM extract increased, L-values significantly decreased while a-value and b-value significantly increased (P<0.001). The hardness and adhesiveness were increased with an increase in PYM extract, and as the storage period increased. In the sensory evaluations, the sample containing 0.5% and 1.0% PYM extract gave good scores. In the Gaeseong-Juak with PYM extract, the acid value, peroxide value, and p-anisidin value of PYM extract groups were found to have a higher oxidative stability than those of 0% PYM extract group (P<0.05). The antioxidative activity of Gaeseong-Juak to which PYM extract was added increased as the content of PYM extract increased (P<0.001). It was suggested that the shelf life of Gaeseong-Juak could be extended by the use of natural antioxidants, reducing the deterioration of the quality of Gaeseong-Juak.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.6
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• pp.807-812
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• 2007

In order to enhance the flavor and storage stability of meat sauce, the manufacturing process of fermented beef-rib sauce was developed in a two-step process. The fermented sauce base was manufactured with Zygosaccharomyces rouxii Y-80 yeast cultivation in raw sauce ingredients for 3 days at $25^{\circ}C$. The fermented beef-rib sauce (FBS) was produced by mixing fermented sauce base with side ingredients. Comparison of the physicochemical and sensory properties with non-fermented beef-rib sauce (NFBS) revealed that the content of ethanol and volatile flavor compounds were higher in FBS; also, the result of sensory evaluation showed that FBS obtained excellent scores for overall taste. To determine the storage stability, FBS and NFBS were incubated at $25^{\circ}C$ for 7 days. The extent of decrease of pH and increase of titratable acidity in NFBS were faster than FBS. After 7 days, ethanol concentrations in FBS and NFBS were 3.77% and 2.04%, respectively. Therefore, based on these results, it can be suggested that storage stability of FBS is superior.

• Korean Journal of Food Science and Technology
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• v.53 no.4
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• pp.479-485
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• 2021

To improve the oxidative stability of Glycyrrhiza uralensis extract (GU), GU extraction conditions were optimized for maximal antioxidant activity, and GU-loaded nanocapsules were prepared by chitosan ionic gelation. The optimized ethanol concentration and extraction time were 83.0% and 32.6 min, respectively, using response surface methodology. The particle size of the GU-loaded nanocapsules ranged from 280 to 370 nm. A GU extract of 0.8 mg/mL and chitosan concentration of 2.0 mg/mL were selected as the optimal conditions for entrapment and loading efficiency. Both free GU and GU-loaded chitosan nanocapsules exhibited concentration-dependent antioxidant activity. However, the antioxidant protection factor of GU was effectively maintained when it was entrapped within the chitosan nanocapsules. In conclusion, chitosan nanoencapsulation is a potentially valuable technique for improving the oxidative stability of GU.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.4
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• pp.570-574
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• 2003

This study investigate the effects of starter cultures on the color stability of Chinese-style sausage. The samples were inoculated with $10^7cfu\;g^{-1}$ meat of either Staphylococcus carnosus or Staphylococcus xylosus. After mixing, curing at either $4^{\circ}C$ or $20^{\circ}C$ for 20 h and then drying at $50^{\circ}C$ for 5 h, the samples were then either vacuum packed or hung at $4^{\circ}C$ and $25^{\circ}C$ (85% R. H.). The pH, nitrite content, nitrosyl pigment content, metmyoglobin and L-, a-, b- values were measured. The pH value still remained above 6.0 during storage. Nitrite residue of all samples decreased after storage at $25^{\circ}C$ for 7 days. The samples inoculated with S. carnosus and S. xylosus had higher nitrite content (20.9-34.7 ppm) than the control (p<0.05). Samples inoculated with S. carnosus and S. xylosus had higher nitrosyl pigment content and lower metmyoglobin content than those of the control. The L- and b- values of all samples decreased but the a- values increased with storage time. The result suggested that S. carnosus and S. xylosus starter cultures be used to improve color stability of Chinese-style sausage.

• Food Science and Biotechnology
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• v.15 no.3
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• pp.453-457
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• 2006

Activity and stability of kiwifruit actinidine was determined in various conditions of pH, salt, and temperature using N-${\alpha}$-CBZ-lysine P-nitrophenyl ester as the substrate. Actinidine activity was low below pH 6, and undetectable below pH 3. The enzyme was stable in a pH range of 6.0-8.5. At $4^{\circ}C$ the enzyme was inactive in the presence of greater than 36% vinegar and in 2 M NaCl. Actinidine at $25^{\circ}C$ was unstable in 24% vinegar but stable in up to 3 M NaCl. With regard to freeze-thaw stability, actinidine retained 85% residual activity after being frozen at $-20^{\circ}C$ for 3 days. Based on Arrenius and Lineweaver-Burk plots, actinidine became unstable at greater than $45^{\circ}C$ with only 30% residual activity remaining after 6 min. The Km, kcat, and kcat/Km values of actinidine were $56\;{\mu}M$, 67/sec, and $1.2\;{\mu}M/sec$, respectively.

• Culinary science and hospitality research
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• v.4
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• pp.129-146
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• 1998

The effects of vitamin E supplement on 15%(w/w diet) perilla or corn oils were studied in rat hepatocellular chemical carcinogenesis induced by modified Solt & Farber model, which consists of 20mg/kg body weight diethylintrosamine(DEN) injection, 3 weeks feeding of 0.02%2-acetylaminofluorene(2-AAF) and partial hepatectomy. The area of placental glutathione S-transferase(GST-P) positive foci tended to be smaller in perilla oil group had lower thiobarbituric acid reactive substances(TBARS) CONTENT. Fatty acid compositions in microsomal membrane were reflected by dietary fatty acid compositions, and not affected by carcinogen treatment or vitamin E supplement. By vitamin E supplement, linolenic acid contents of perilla oil group were much increased. By carcinogen treatment, membrane stability decreased significantly in corn oil, but maintained in perilla oil groups Vitamin E supplemental effect was noticed only in the corn-carcinogen group. Perilla oil may prevent hepatocarcinogenesis by maintaining membrane stability and by reducing cytochrome P-450 content. Vitamin E supplement did not seem to have the effect on hepatocarcinogenesis, but prevented lipid peroxidation, reduced cytochrome P-450 content and maintained membrane stability.

• Food Science and Biotechnology
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• v.15 no.5
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• pp.746-751
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• 2006

The effects of resistant starch (RS) and non-starch polysaccharide (NSP) addition on the properties of hard wheat flour were investigated. Total dietary fiber (TDF) levels of various NSP ranged from 78.3-100.0%, but TDF and RS levels of autoclaved RS3 and cross-linked RS4 were 16.1 and 35.0% and 13.2 and 90.9%, respectively. DF-supplemented flour increased swelling power, but RS4-supplemented flour exhibited the lowest it. Solubility increased with the addition of pectin and RS3, but decreased with the addition of cellulose and RS4. RS-supplemented flour had increased lightness (L), but decreased values of redness (a) and yellowness (b). RS3 and pectin increased the dough development time, but RS4, cellulose, and chitosan decreased it. The water absorptions of pectin- and RS4-supplemented flours increased, however the dough stability decreased. The initial pasting temperatures of RS- and NSP-supplemented flours increased regardless of amount added, but the maximum peak viscosity decreased for all except the pectin-supplemented flour.