• Applied Biological Chemistry
• /
• v.51 no.1
• /
• pp.11-16
• /
• 2008

The extraction conditions for resveratrol production from grape fruit stem, which is a by-product of grape processing, were optimized to develop high-functional grape-based products. Additionally, the bioefficacy of grape fruit stem extract (GFSE) as an antioxidant agent was evaluated. Resveratrol was extracted using various experimental conditions such as extractant type, extractant concentration, raw material-extractant ratio, extraction time and temperature, and the results were analyzed using a statistical program (SPSS). The resveratrol yield was the highest when 80% ethanol with a raw-material-extractant ratio of 1:10 (w/v) was used. In addition, the optimal temperature and time were selected as $60^{\circ}C$ and 90 min, respectively. When the antioxidant activity was analyzed and expressed as DPPH radical scavenging activity and SOD-like activity, the antioxidant activity of GFSE was higher than that of BHT, BHA and L-ascorbic acid. Finally, it was found that GFSE could be used as a raw material for the production of high antioxidant agents.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.39 no.10
• /
• pp.1495-1502
• /
• 2010

This study was for the industrial application of functional food ingredients from whole fruits of sweet persimmon. Whole fruit and pulp of sweet persimmons were divided, and then lyophilized and powdered. Contents of crude fiber, vitamin C, and mineral were significantly higher in whole fruit than pulp of sweet persimmon. The amino acid content of whole fruit was 1.4 times higher than those of sweet persimmon pulp. In the biological activities of water and ethanol extracts from whole fruit and pulp of sweet persimmon, ethanol extract was higher than water extract, and whole fruit was higher than its pulp. The result which compared the biological activities of the water and ethanol extract from lyophilized sweet persimmon showed that total phenolic content was significantly higher in whole fruit of sweet persimmon, but flavonoid contents were not significantly different. Especially ABTS, NO radical scavenging activity, reducing power and tyrosinase inhibition activity were significantly higher in whole fruit extract than pulp extract of sweet persimmon. The relatively high content of fiber and vitamin C, and biological activity of whole fruit than pulp of sweet persimmon may be make it preferable as functional food materials for secondary processed goods.

• Journal of Life Science
• /
• v.17 no.12
• /
• pp.1734-1738
• /
• 2007

The biological activities of strawberry were investigated during frozen storage. The concentrations of total phenolic content in strawberry juice and water extract were $2.342{\mu}g/ml\;and\;2.235{\mu}g/ml$, respectively. The total flavonoid content in strawberry juice and water extract were $200.36{\mu}g/ml\;and\;201.07 {\mu}g/ml$. respectively. Antioxidant activities of strawberry juice and water extract were determined. The DPPH of strawberry juice (94.2%) was higher than the water extract of strawberry (93.5%). ABTS of strawberry juice and water extract were 99.9% and 100.0%, respectively. Xanthine oxidase inhibitory activity and SOD-like activity of strawberry of water extracts were higher than those of strawberry juice. The changes in the antioxidant activity of strawberry was insignificant until 6 months of frozen storage. Therefore, it was expected that frozen storage of strawberry was useful preservation expedient for consistent supply of raw materials.

• Korean Journal of Food Science and Technology
• /
• v.4 no.2
• /
• pp.77-83
• /
• 1972

In order to study the processing adaptability of naked barley, SEDOHADAKA variety produced in Cheolanam-do(1971) was milled after polishing and examined with respect to its proximate principles, amino acid composition, viscosity, raising power, and amylose content, alkali number, blue value and X-ray diffraction pattern of its starch. The results are summarized as fllows: 1) Crude fiber content of naked barley which was milled at 81.6% (A), 79.2% (B) and 74.1% (C) was $2.48{\sim}2.36%$, indicating higher level than wheat flour. 2) Whereas the initial gelatinization temperature of naked barley flour was similar to that of wheat flour, the value of naked barley starch was $89.5^{\circ}C$, higher than that of wheat starch, Amylose content of naked barley starch was 28.5%, similar to wheat starch. 3) Raising power of naked barley starch was generally lower than that common cereal starches. 4) According to the X-ray diffraction pattern diagram, the degree of crystallization was lower in naked barley starch than in non-glutinous rice starch.

• Korean Journal of Food Science and Technology
• /
• v.48 no.1
• /
• pp.92-95
• /
• 2016

Ultra-high pressure (UHP) was applied to glutinous rice (Dongjin) and brown rice (Shindongjin) to determine its effects on the textural characteristics of cooked rice and bacterial reduction in uncooked rice. Hardness and stickiness of the cooked glutinous and brown rice pretreated with 500 MPa for 5 min were significantly attenuated compared to that of the control rice (p<0.05). After the UHP treatment, particles of the glutinous and brown rice were observed to be finer when cross sections of the rice were analyzed using field emission scanning electron microscope. The total bacterial count in the brown rice treated with 600 MPa for 5 min was reduced from $10^7CFU/g$ to $10^4CFU/g$, while the number of thermoduric bacteria in the brown rice was not significantly different after the UHP treatment. These results suggest that UHP may be an effective method for improving texture of dried rice and to reduce bacterial count in raw rice.

• Korean Journal of Food Science and Technology
• /
• v.46 no.5
• /
• pp.660-664
• /
• 2014

This study aimed to investigate the effects of various soft steam treatments, namely, forced convection-boiler, forced convection-fan, and natural convection, on the pretreatment characteristics of potatoes. In this study, potatoes were exposed to various cooking conditions, including steaming method, treatment time (0-60 min), and temperature (60, 70, $80^{\circ}C$). Then, changes in temperature, cook value, ascorbic acid content, moisture content, and weight loss in the fresh and steam-treated samples were measured and evaluated. The results clearly showed that natural convective steaming was superior to other treatments in terms of heating characteristics, cook value (FC-b: $46.4{\pm}1.7$, FC-f: $21.8{\pm}1.1$, NC: $52.1{\pm}1.9min$ at $80^{\circ}C$), ascorbic acid content (FC-b: $36.5{\pm}2.7$, FC-f: $28.5{\pm}2.9$, NC: $48.2%{\pm}2.5%$ at $80^{\circ}C$), moisture retention (FCb: $74.6{\pm}0.8$, FC-f: $71.5{\pm}0.5$, NC: $77.6%{\pm}0.4%$ for 60 min at $80^{\circ}C$), and weight loss (FC-b: $13.9{\pm}0.8$, FC-f: $15.6{\pm}0.6$, NC: $10.6%{\pm}0.7%$ for 60 min at $80^{\circ}C$) for thermally processed potatoes.

• Korean Journal of Food Science and Technology
• /
• v.46 no.3
• /
• pp.390-393
• /
• 2014

The effects of roasting temperature and time on the antioxidant activities of tartary buckwheat were investigated. Compared to raw seeds (2.05 mg TAE/g), seeds roasted at $175^{\circ}C$ for 5 min showed significantly higher total polyphenol content (p<0.05), while those roasted at $250^{\circ}C$ for 10 min showed significantly lower total polyphenol content (2.77 and 2.56 mg TAE/g, respectively). The electron-donating abilities of tartary buckwheat seeds increased with an increase in the roasting time at lower temperatures (p<0.05). However, seeds roasted at a higher temperatures ($250^{\circ}C$) for 10 min showed significantly lower electron-donating abilities (p<0.05). Seeds roasted at $175^{\circ}C$ showed adequate L values, regardless of the roasting time. In contrast, seeds roasted for 10 min at $250^{\circ}C$, showed markedly lower L values. Our results suggest that the roasting temperature and time must be controlled to produce high-quality tartary buckwheat products.

• Korean Journal of Food Science and Technology
• /
• v.48 no.5
• /
• pp.492-495
• /
• 2016

This study aimed at investigating the influence of different rice varieties (Palbangmi, Saegoami, Mimyeon, Dasan-1, Hanarm, Boramchan, and Baegjinju) on the preparation process of rice cookies. Rice grains were pulverized by dry milling and subsequently screened using a 100-mesh sieve. Dasan-1, Hanarm, and Palbangmi flours showed low water absorption index (WAI) compared to other rice flours. The spread ratios of the cookies prepared with Dasan-1, Hanarm, and Palbangmi flours reached higher values than those obtained with other rice varieties. As a result, the hardness of the cookies prepared with Dasan-1, Hanarm, and Palbangmi flours was relatively low. On the contrary, cookies prepared with Saegoami, Boramchan, and Baegjinju flours showed inadequate qualities because they contained relatively high levels of damaged starch, which increased water absorption in the cookie dough. The WAI value of rice flour could be the most important indicator to determine the quality of rice cookies.

• Korean journal of food and cookery science
• /
• v.21 no.2 s.86
• /
• pp.263-269
• /
• 2005

Citrus juice, a concentrate manufactured by the Jeju Provincial Corporation, was converted into vinegar orderly by alcohol and acetate fermentation. The juice with 6 folds dilution by distilled water was used as the sole nutrient source through out experiments. Diluted juice contained $12.96^{\circ}Brix$ of total sugar, $0.632\%$ of total acid and $20.23{\mu}g/m{\ell}$ of hesperidin. Naringin was not detected from the juice. Citrus wine having $5.6\~6.3\%$ alcohol was produced from diluted juice by 3 days of fermentation at $28^{\circ}C$. A kind of malomelo yeast CMY-28 was used for wine fermentation. The wine was succeedingly fermented for 8 days at $30^{\circ}C$ after inoculation of seed vinegar which contained active cells of acid producing bacteria CV1. Inoculum size of seed vinegar was controlled to $10\%$(v/v) of citrus wine. The wine converted into vinegar by the fermentation. Citrus vinegar, the final product of fermentation, was colored with very thin radish-yellow and transparent. It's acidity ranged between $5.8\~6.2\%$ as acetic acid. The vinegar got the best score by sensory test among several natural fruit vinegars. It was clear from the results that citrus vinegar in high quality could be produced from concentrated citrus juice, however fermentation conditions should be improved to reduce the amount of reducing alcohol.

• The Korean Journal of Food And Nutrition
• /
• v.27 no.1
• /
• pp.50-58
• /
• 2014

Makgeolli, known as takju, is a traditional alcoholic beverage which is native in Korea. It is made from various rice and other cereals. This study is carried out to compare the physicochemical characteristics and functional quality of makgeolli from various rice cultivars according to different amylose contents and amylopectin compositions. The 'Goami2', 'Goami3', and 'Goami4' have high amylose contents and lower proportional degrees of polymerization (DP) 6~12 and higher proportions of DP 13~24 in amylopectin of milled rice. Various variations are shown in pasting properties (viscosities) and gelatinization characteristics, and it is supposed to be related to both the amylose contents and the amylopectin compositions of raw rice. The makgeolli is being manufactured by using the 2-step-brewing method. The makgeolli is analyzed for alcohol contents, pH levels, total acids, Hunter color values and organic acid compositions. The makgeolli of 'Goami2', 'Goami3', and 'Goami4' have showed higher makgeolli yields, lower ethanol contents and less sweetness than other cultivars, and they also have high non-digestible carbohydrates contents which are derived from their high non-digestible carbohydrates contents in milled rice. Therefore, we are able to suggest that it is necessary to improve the makgeolli fermentation processes of 'Goami2', 'Goami3', and 'Goami4'.