• The Korean Journal of Food And Nutrition
• /
• v.22 no.3
• /
• pp.387-395
• /
• 2009

This study was conducted to investigate the effects of starch concentrations and heating conditions on the gel characteristics of arrowroot starch. Arrowroot starch gels with various pHs, and starch concentrations, were prepared using different temperatures and heating times, and then stored for 24 hrs at $4^{\circ}C$. The hardness of sample gels made at pH 2.0 and 4.0 increased as the starch concentration increased from 7% to 10%, with the maximum value of 94 N being obtained when the gel was prepared at pH 4.0 with a starch concentration of 10%. The maximum hardness of samples prepared with concentrations of starch ranging from 7~9% appeared at $80^{\circ}C$, regardless of the heating temperature and time. Furthermore, the hardness of samples prepared at greater than $100^{\circ}C$ was relatively lower than that of samples prepared at other temperatures. When a starch concentration of 8% was used, the degree of gelatinization(DR) increased as the heating temperature increased, with the maximum value of DR being about 76% at $120^{\circ}C$, regardless of heating time. After storage for 24 hrs, the hardness of samples prepared at $70^{\circ}C$, $80^{\circ}C$ and $90^{\circ}C$ appeared to decrease, while that of samples prepared at $100^{\circ}C$, $110^{\circ}C$ and $120^{\circ}C$ increased. The correlation between hardness and the degree of gelatinization or retrogradation was very high when samples were prepared at $80^{\circ}C$ with a starch concentration of 9%, as indicated by a correlation coefficient of greater than 0.95. Overall, the microstructures of freeze-dried arrowroot starch gel were composed of a continuous network of amylose and amylopectin with fragmented ghost structures in an excluded phase, but these ghost structures were more evident after storage and with increased heating temperature.

• Journal of the East Asian Society of Dietary Life
• /
• v.25 no.1
• /
• pp.99-110
• /
• 2015

The purpose of this study was to evaluate the inhibitory effects of commonly consumed vegetables in Korea on lipid accumulation and production of pro-inflammatory cytokines related to obesity/metabolic syndrome. Using KNHANES (Korea National Health and Nutrition Examination Survey) raw data ($1^{st}$; 1998, $5^{th}$; 2010, 2011) and a literature search, we selected vegetables for study. Edible portions of samples were prepared, ethanol-extracted, and then freeze-dried. 3T3-L1 adipocytes and HepG2 hepatocytes cells were used as in vitro models. Lipid accumulation determined by Oil-red O staining showed that all samples except bracken had inhibitory effects on lipid accumulation in 3T3-L1 adipocytes. Especially, crown daisy and mugwort effectively reduced accumulation of lipids, and their inhibition rates were more than 60% of the control group. Young pumpkin, leeks, crown daisy, and mugwort showed significantly decreased MCP-1 levels compared to the control group. However, adiponectin protein level did not increase in the vegetables experimental group. In HepG2 hepatocytes, all samples showed inhibitory effects on lipid accumulation at one of the two concentrations. Although adiponectin protein levels did not increase, MCP-1 protein levels decreased in adipocytes. Further, lipid accumulation in adipocytes and hepatocytes decreased. In conclusion, all samples showed one or more improved obesity/metabolic syndrome indicators. Among them, young pumpkin, leeks, crown daisy, and mugwort were selected as the most effective portions of vegetables based on improvement of obesity/metabolic syndrome-related indicators.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.43 no.3
• /
• pp.389-396
• /
• 2014

The physiological properties of 70% ethanol extracts from Portulaca oleracea with different extraction methods (reflux extraction, RE; autoclave extraction, AE; low temperature high pressure extraction, LTPE) were investigated. The freeze-dried powder yields of RE, AE, and LTPE were 33.78%, 30.80%, and 11.05%, respectively. The color values of L and b were higher in LTPE, and the chroma values were higher in AE and LTPE compared to RE. The total polyphenolics and proanthocyanidin contents in LTPE were significantly higher than in other extracts. The amount of substances related to flavonoids contents was highest in RE (4.30 mg/g), followed by AE (4.06 mg/g), and LTPE (4.00 mg/g). DPPH radical scavenging ability with a concentration of 500 mg% (w/v) were in the following order; LTPE (88.87%)> RE (83.84%)> AE (80.67%). Further, the reducing power, ABTS radical scavenging ability, and nitrite scavenging activity was observed in the same tendency as seen with the DPPH radical scavenging ability. However, the ferrous ion chelating activity of RE (85.45%) and AE (83.88%) was significantly higher than that of LTPE (75.60%). ${\alpha}$-Glucosidase inhibitory activities of RE and LTPE with a concentration of 100 mg% were significantly higher than AE. Xanthine oxidase, and acetylcholinesterase inhibitory activities of LTPE were higher than the other extracts. These results suggest that the extracts from Portulaca oleracea have the potential to act as functional materials, and components of Portulaca oleracea could be effective in the prevention of Alzheimer's disease, and may be used to develop various functional food products.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.41 no.8
• /
• pp.1049-1056
• /
• 2012

The antioxidant activities and antibacterial activities of grape pomace fermented using a variety of useful microorganisms were analyzed. There were several experimental groups: the control, with non-fermented grape pomace; the BS group, fermented by Bacillus subtilis; the LP group, fermented by Lactobacillus plantarum; the LC group, fermented by L. casei; the CU group, fermented by Candida utilis; the Y1 group, fermented by Saccharomyces cerevisiae strain CHY1011; the Y2 group, fermented by S. cerevisiae strain ZP 541; and the M group, fermented by a mixed strain culture of LP, LC, and CU. The yield of freeze-dried powder of fermented grape pomace by BS, LP, LC, CU, Y1, Y2, and M was 10.74%, 9.36%, 8.68%, 9.55%, 7.49%, 9.60%, and 9.71% w/w, respectively. The total polyphenol content of grape pomace showed the highest value in the control, but the fermented LP had higher total polyphenol content than those of other fermented grape pomace. The control and fermented LP had 0.16 mg/mL and 0.28 mg/mL as $IC_{50}$ values on DPPH radical scavenging, and 0.22 mg/mL and 0.53 mg/mL of ABTS radical scavenging activity, respectively. The FRAP value (5 mg/mL) showed the highest value on fermented LP (2.44 mM) but did not show a significant difference in the control group (12.27 mM). The fermented LC showed the antimicrobial activities against B. cereus (11 mm), B. subtilis (11 mm), Staphylococcus aureus (12 mm), Escherichia coli (12 mm), Enterobacter cloacae (10.5 mm), Salmonella enterica (11.5 mm), and Pseudomonas aerugionsa (11 mm) at 5 mg/disc, but the control and other fermented grape pomace did not show antimicrobial activities. Thus, fermented grape pomace by LC is shown to be producing a material that has antibacterial activity. In conclusion, grape pomace fermentation using various lactic acid bacteria strains showed excellent effects in promoting the production of functional materials. Especially, using L. casei exhibited an increase in antibacterial activity, and using L. plantarum exhibited antioxidant activity.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.10
• /
• pp.1536-1544
• /
• 2005

We have investigated physiological effects of soy ice cream with oligosaccharide on oxidative stress and fecal microflora in streptozotocin-induced diabetic rats. Parched soybean powder (7.6$\%$, w/w) substituted skimmed milk and cream, soybean oil (7.6$\%$, w/w) for milk oil, and fructooligosaccharide (9.5$\%$, w/w) for sucrose. Five types of ice cream were prepared: regular, oligosaccharide-supplemented regular, soy, oligosaccharide - supplemented soy, and oligosaccharide - supplemented black soybean ice cream . Freeze - dried ice cream was supplemented to AIN93-based diets at 30$\%$ (w/w) containing 6.5$\%$ soy and 4.5$\%$ fructooligosaccharide. Diabetes was induced by intramuscular administration of streptozotocin, and experimental diets were given for 4 weeks. Plasma concentration of thiobarbituric acid reactive substances (TBARS) was significantly increased in the diabetic rats compared with the normal rats, then was significantly decreased with feeding soy ice cream containing diet compared with regular ice cream containing diet among the diabetic groups. The levels of TBARS in liver were decreased in the rats that were fed either soy or oligosaccharide ice cream compared with the rats that were fed regular ice cream. Erythrocyte superoxide dismutase activity was significantly increased in the rats fed soy ice cream compared with the rats fed regular ice cream. Erythrocyte glutathione peroxidase and catalase activities were significantly increased in the rats fed black soybean ice cream. Fecal concentrations of Lactobacilli were significantly higher in the rats fed soy ice cream and oligosaccharide- supplemented soy ice cream than that of the rats fed regular ice cream. Fecal concentrations of Bifidobacteria were significantly higher in the rats fed oligosaccharide- supplemented soy ice cream than that of the rats fed regular ice cream. In conclusion, oligosaccharide- supplemented soy ice cream suppressed lipid peroxidation and improved the got microbiota in diabetic rats compared with milk-based regular ice cream.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.18 no.6
• /
• pp.550-556
• /
• 1985

In order to evaluate the marine mollusc muscle as foodstuff not only from the biochemical aspect but also from the view point of food science, we have analyzed the protein and amino acid compositions of the echiurid (Urechis unicinctus) and sea hare (Aplysia kurodai) muscle. The protein quality of the muscles was also investigated using in vitro methods based on in vitro digestibility, predicted digestibility, computed PER (C-PER) and discriminant computed PER(DC-PER). The remarkable feature of the protein compositions of the both muscles was that water soluble protein occupied a large amount of the muscle protein with fairly lower contents of the salt soluble protein. From the analysis of SDS-PAG electrophoresis, the sarcoplasmic proteins in the echiurid and the sea hare muscles were composed of 15 and 10 subunits, respectively. The free amino acid compositions of the total amino acids in the echiurid and sea hare muscle were characterized with $75\%$ of glycine and alanine, and with $78\%$ of taurine, respectively. The amino acid anaylsis of both muscle proteins showed that the echiurid muscle was rich in glycine, aspartic acid, glutamic acid, arginine and lysine, but was poor in cysteine, while the sea hare muscle was rich in glycine, glutamic acid, aspartic acid and arginine, but was negligible in cysteine and tryptophan. In the total amino acid profiles of the freeze dried muscles in echiurid and sea hare, there was not found a significant difference compared to the amino acid compositions of the muscle proteins. Predicting the protein quality of the echiurid and sea hare muscles using the in vitro method, it was apparently low compared to the muscle protein of fishes.

• Korean Journal of Poultry Science
• /
• v.39 no.2
• /
• pp.121-131
• /
• 2012

To investigate the effect of dietary supplementation of freeze-dried plum (Prunus mume Siebold and Zucc., PMS) or omija meal (Schizandra chinensis Baill.; SCB) on growth performance, organ weights, blood biochemical profiles and antioxidant defense system, a total of 96, 3-day-old male broiler chickens were assigned to three dietary groups: (1) control diet, (2) control diet supplemented with PMS at 0.2%, (3) control diet supplemented with SCB at 0.2%. In vitro antioxidant activity, plum and omija extracts showed a significantly higher radical scavenging activity (RSA). In particular, omija extract showed much higher RSA than plum extract. Dietary addition of plum or omija did not affect body weight, feed intake, feed conversion and the relative weight of digestive organ in birds. Plasma triglyceride significantly (P<0.05) increased in birds fed the diet supplemented with omija compared with those fed control diet without affecting the other blood biochemical components. Furthermore, reduced form of glutathione (GSH) in the liver or muscle significantly (P<0.05) increased in birds fed the diet fortified with plum and omija. However, the specific activities of superoxide dismutase (SOD), glutathione peroxidase (GPX) and glutathione-S-transferase (GST) and MDA (malondealdehyde) in the intestine, liver and muscle were not altered by dietary antioxidant sources. In conclusion, dietary plum and omija resulted in a positive effect on some antioxidant indicators such as increased in vitro RAS in extracts and in vivo GSH level in the liver and muscle without affecting growth performance. Therefore, dietary addition of 0.2% of plum or omija could be applicable as potential antioxidant sources in broiler chick production.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.56 no.1
• /
• pp.80-87
• /
• 2011

Panax ginseng has been used as a traditional medicine for several centuries in Korea. A laboratory experiment using methanol extracts of freeze-dried leaves and roots in the different ages of P. ginseng was conducted to determine the content of phenolics and flavonoids, antioxidant activity and cytotoxicity. The results indicate that the total phenolics level [mg ferulic acid equivalents (FAE) $kg^{-1}$ DW] was higher in leaves (22.0 to 76.3 mg $kg^{-1}$) than roots (19.0 to 28.3 mg $kg^{-1}$) of P. ginseng. The total content of phenolics in roots increased with increase in age of P. ginseng from one to six years. However, the content of phenolics in P. ginseng leaf decreased with the increase in age. Total flavonoid [mg naringin equivalents $kg^{-1}$ DW] was more detected in the leaves (30.3 to 138.6 mg $kg^{-1}$) than in the roots (0.0 to 10.6 mg $kg^{-1}$) of P. ginseng. The total flavonoid level in leaves decreased with increase in age of P. ginseng. The antioxidant potential of the methanol extracts from the plants dose-dependently increased. DPPH free radical scavenging activity was higher in leaves (36.9 to 82.8%) than in roots (14.8 to 39.4%), and in young plants than in old ones. According to 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, the methanol extracts from 5 year-root part showed the highest cytotoxicity against Calu-6, followed by 2 year- and 3 year-roots. However, the methanol extracts from 6 year- and 4 year-roots had lower cytotoxicity. Total phenolics content in both leaves and roots was highly correlated with the DPPH radical scavenging ($r^2=0.7366$ to 0.7870) and nitrite scavenging ($r^2=0.5604$ to 0.8794) activities, suggesting that they contribute to the antioxidant properties of the P. ginseng plants.

• The Korean Journal of Food And Nutrition
• /
• v.19 no.3
• /
• pp.243-253
• /
• 2006

This study was designed to investigate the feasibility of utilizing concentrates of sunmul(soybean curd whey), the waste by-product of soybean curd processing, as functional food ingredients. Sunmul was concentrated by nanofiltration fo11owing ultrafiltration and then freeze-dried. The oil adsorption capacity of the nanofiltraion(NF) powder(97.33g/100g) was similar to that of sunmul powder(94.17g/100g), but was lower than that of ISP(isolated soy protein). However, the water holding capacity of NF powder could not be determined because the NF powder completely dissolved in water. The protein solubilities of sunmul powder and ISP in distilled H$_{2}$O, 0.1M and 0.5M NaCl were lowest at pH 4.0 and increased at more acidic or alkaline conditions. However, the protein solubility of NF powder was at its minimum at pH 6.0 and increased at more acidic or alkaline conditions. Emulsifying activity indexes of NF powder in 4% and 6% solution were minimal at pH 4.0 and 6.0, respectively, which were 3 to 8 times lower than that of sunmul powder. The emulsion stability of 4% sunmul solution was lowest at pH 4.0, but that of NF powder was highest at pH 5.0 and decreased at more acidic or alkaline conditions at all concentrations of solution. The total free amino acid contents of protein in sunmul, and NF power were 99.07 and 2,110.10mg%, respectively, and NF powder exhibited especially high threonine content. Rapid viscosity analysis of dough with 1 to 5% added NF powder demonstrated that all of the peak and final viscosities decreased with increasing NF powder concentration compared to the control.

• Korean journal of food and cookery science
• /
• v.18 no.2
• /
• pp.216-224
• /
• 2002

Persimmon powder (PW), which was prepared by pulverizing freeze-dried persimmon with peels, was added to Maejakgwa up to 25% of wheat flour. Maejakgwa samples were prepared by the central composit experimental design for three independent variables: amount of PW, frying time, and frying temperature. The color of Maejakgwa was influenced more by the frying time and temperature than the content of added PW. Crispiness and adhesiveness were highly correlated with overall preference. Although the amount of PW affected the adhesiveness, the adhesiveness could be controlled by the frying temperature and time. Frying temperature was the most effective factor on the crispness and hardness. The addition of high amount of PW obviously increased the sweetness and aftertaste. However, at the low amount of PW, frying for longer time at high temperature also increased the sweetness and aftertaste. Center sample (15% PW, frying for 4 min at 145$\^{C}$) showed the best score at the overall preference. Overall preference was improved as the sample was fried at high temperature/short time or at low temperature/long time. Maejakwa prepared with high amount of PW at 20% showed no significant difference with the center sample for overall preference as prepared by frying for 3 min at 155$\^{C}$. The optimum condition obtained by superimposing color, crispiness and overall preference was frying for 5∼6 min at 131∼140$\^{C}$.