• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.11
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• pp.1691-1695
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• 2016

The objective of this study was to determine the antioxidant activities of rice bran extracts by three different extraction methods. Rice bran was extracted by solvent extraction, saponification extraction, and supercritical fluid extraction. The antioxidant activities of the rice bran extracts were determined based on ABTS and DPPH radical scavenging activities, reducing power, and lipid peroxidation inhibitory activity. The unsaponifiable matter (USM) extracted by the saponification method showed higher ABTS (671.7 mg Trolox equivalent antioxidant capacity (TEAC)/g) and DPPH (330.7 mg TEAC/g) radical scavenging activities as well as reducing power ($A_{700}=1.14$) than those of the solvent extract (ME) and supercritical fluid extract (SFE). Inhibitory effect on lipid peroxidation was higher in USM (68.7%) and SFE (75.4%) compared to ME (47.8%). USM indicated relatively higher antioxidant activities compared with those of SFE and ME. These results show that the saponification method for extraction of USM from rice bran extracted was the most effective method for enhancement of antioxidant activity. In addition, these extracts from rice bran could be used as functional ingredients in the food industry.

• Korean Journal of Breeding Science
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• v.43 no.4
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• pp.297-303
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• 2011

In order to confirm the biological activities of rice bran and hull, total phenolic content, antioxidant and anticancer activities were examined in three rice varieties that have different seed coat colors such as brown, black, and purple. The antioxidant activity was measured by free radical scavenging assay including DPPH, $ABTS^+$ and reducing power activity. The anticancer activity was evaluated by WST assay with human HepG2 cell lines. As the result, Huegjinju, black seed coat rice, showed higher of the total phenolics contents in both bran and hull, than purple Jeojinju and brown Ilpum. In the antioxidant activity, Heugjinju showed the highest among the bran extracts, but the activities of hull extracts were similar in three varieties. In the anticancer activity to HepG2 cell line, the hull extract was 20% higher than that of bran extract in the average of three varieties. The hull extracts of Ilpum and Jeokjinju showed similar anticancer activites about 92%, and that of Heugjinju showed the lowest activity of 30.4%. The anticancer activities of hull extracts in three varieties showed positive correlation with total phenolics contents, DPPH radical scavenging activities and reducing power activities. In conclusion, the rice bran and hull showed potent antioxidant and anticancer activities varied in three varieties that have different seed coat colors.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.4
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• pp.624-630
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• 2010

This study was conducted to determine antioxidant compounds and antioxidative activities of by-products including rice bran and half-crashed rice by rice milling. DPPH, ABTS radical scavenging activities and reducing power have been used to investigate the relative antioxidative activities of 70% EtOH extracts from by-products. The contents of total polyphenol, total flavonoid and $\gamma$-oryzanol in EtOH extracts were measured by spectrophotometric methods, and vitamin E was carried out by HPLC. Ethanol extract from rice bran showed markedly antioxidative activity than that from half-crushed rice. Among EtOH extracts from milling by-products, rice bran of 'Hongjiju' tended to have the most effective antioxidative activity compared to the others. These results suggested that by-products of rice milling have the potent antioxidative activity and these activity are partly due to the antioxidative compounds present in by-products including rice bran and half-crushed rice.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.101-101
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• 2017

Beta-glucan is a polymerized polysaccharide on beta-1,3 chemical bonds. It has the main pharmacological action of various anticancer mushrooms and is colorless and odorless. In addition, it enhances phagocytosis of macrophages against mycobacterium tuberculosism and increases resistance of host against food poisoning bacteria. Owing to these advantages, beta-glucan was used in various health supplement foods such as immune boosters, hypotensive agent and hypoglycemic agent. Our study was aimed to investigate the effective components of beta-glucan, which was optimized via the contents of Sarcodon aspratus and rice bran. First, the mixture ratio condition of Sarcodon aspratus and rice bran were respectively 10:0, 7:3, 5:5, 3:7, and 0:10. The raw materials were fabricated using hot water extraction method. Distilled water of 100 mL was added to the raw material and extracted. After the extraction processed, the content of effective components was analyzed. The absorbance of beta-glucan was measured using a beta-glucan kit (Megazyme, (1-3) (1-4) BETA-D-GLUCAN ASSAY KIT). The absorbance analysis was repeated three times for accurate analysis. After the extracts were lyophilized, the yields of extracted raw materials according to the mixture ratio conditions of Sarcodon aspratus and rice bran (10:0, 7:3, 5:5, 3:7, and 0:10) were respectively 33.1%, 34.5%, 35.3%, 30.7%, and 24.3%. The absorbance was 1.52, 1.47, 1.50, 1.79, and 1.56, respectively. As a result, the optimum ratio of beta-glucan is 3:7 at Sarcodon aspratus and rice bran. This study suggested that the optimal amount of beta-glucan could be used as a health supplement foods and food additive such as immune boosters, hypotensive agent and hypoglycemic agent. However, the new condition (temperature, time) of hot water extraction to maximize the content of beta-glucan could be considered, could be necessary to compare with the existing extracts.

• Korean Journal of Food Science and Technology
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• v.50 no.5
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• pp.528-534
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• 2018

The current study investigated the effects of enzyme treatment on black rice (Oryza sativa L.) aleurone layer extracts. Different enzymes (lipase, lecitase ultra and lipopan 50BG) were used to test anti-oxidant and anti-inflammatory activities in vitro. The antioxidant activities of enzyme treated or non-enzyme treated extracts of black rice bran were evaluated via 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity. Lipase treated extracts of black rice bran showed higher antioxidant activity compared to that of non-enzyme treated extracts. Anti-inflammatory activities of enzyme treated black rice bran extracts on nitrite production and tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$) secretion, were tested using a nitric oxide (NO) colorimetric assay kit and an enzyme-linked immunosorbent assay (ELISA) kit. The ethanolic extract of enzyme treated black rice bran decreased the levels of nitric oxide production and pro-inflammatory cytokines, such as tumor necrosis $factor-{\alpha}$, in a lipopolysaccharidestimulated RAW 264.7 cell culture. These findings indicate that enhanced anti-oxidant and anti-inflammation activities of the ethanolic extracts of enzyme treated black rice (Oryza sativa L.) aleurone layers, may be attributed to molecular conversion of ingredients in enzyme catalyzed reactions.

• Korean Journal of Food Science and Technology
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• v.42 no.5
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• pp.593-597
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• 2010

This study investigated the properties and antioxidative activities of phenolic acid concentrates of rice bran. Rice bran contains bioactive substances such as phenolic compounds, which can provide health benefits as natural antioxidants. This study examined how levels of phenolic acids can be obtained efficiently through various extraction methods. The extractions of defatted rice bran were followed by using ethylacetate (RBE-I), ethylacetate after alkaline hydrolysis (RBE-II), and 80% methanol (RBE-III). For all extracts, yields (%), total polyphenol contents (TPC), various phenolic acids and antioxidative activities were estimated. RBE-II had the highest total polyphenol contents (526.72 mg/100 g rice bran) and showed high antioxidative activity (74.7%). To concentrate the phenolic acids, RBE-II was passed through Sep-pak $C_{18}$ Vac cartridge and F1-RBE-II was collected by the elution of 50% methanol. The total phenolic content of F1-RBE-II (736.8 mg/100 g rice bran) was higher than that of RBE-II (367.1 mg/100 g rice bran), and the ratios of ferulic acid (73%) and sinapic acid (14%) increased. As RBE-II was analysed by HPLC, 6 different phenolic acids were found via chromatography, whereas F1-RBE-II showed 5 different peaks and the major phenolic acid was identified as ferulic acid. The ABTS radical scavenging activity of F1-RBE-II was the highest among the rice bran extracts. In a ${\beta}$-carotene-linoleic acid model system, linoleic acid oxidation was reduced by F1-RBE-II (73%) and RBE-II (35%).

• Preventive Nutrition and Food Science
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• v.7 no.2
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• pp.151-156
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• 2002

Antioxidant activity or green tea extracts (GTE) was evaluated in soybean oil (SBO), rice bran oil (RBO) and winterized rice bran oil (WRBO) stored at 63$^{\circ}C$ for 36 days. Lipid oxidation of the oils was determined using the active oxygen method (AOM), peroxide value (POV), change in unsaturated free fatty acid concentrations and by sensory evaluation. SBO had a higher concentration of the polyunsaturated fatty acids, linoleic and linolenic acid than RBO and WRBO. WRBO and RBO were more stable against lipid oxidation than SBO. Addition of GTE (200 ppm) to the stored oils, increased the induction period (IP) in AOM, reduced the increase in POV, and lessened the change in unsaturated fatty acids. Furthermore, GTE prevented the development of rancid flavors resulting from storage, all of which demonstrate the protective antioxidative activity of GTE. However, oil color became darker in the GTE treated oils. The antioxidant protection of GTE was most effective in RBO.

• The Korean Journal of Food And Nutrition
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• v.26 no.1
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• pp.1-7
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• 2013

This study was conducted to determine antioxidant compounds and antioxidant activities of rice bran at temperatures of $10^{\circ}C$, $25^{\circ}C$, and $60^{\circ}C$ using 70% ethanol solution. DPPH, ABTS radical scavenging activities and reducing power have been used to investigate the relative antioxidant activities of extracts. The contents of total polyphenol and total flavonoids in the 70% ethanol extracts were measured by spectrophotometer. The total polyphenol content in the rice bran extracts were 790.39~930.07, 782.71~1,039.57, and 848.22~1,052.96 mg gallic acid eq./100 g in $10^{\circ}C$, $25^{\circ}C$ and $60^{\circ}C$, respectively. Antioxidant activities, such as DPPH, ABTS radical scavenging activity and reducing power, in all cultivars and temperatures was the highest in Cheonghaejinmi rice bran extracted at $25^{\circ}C$. The results obtained in the in vitro models suggest that extracts from rice bran, especially Cheonghaejinmi, has significant health-promoting effects, as it exhibits antioxidant activities.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.464-469
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• 1997

Rapid visco-analyzer (RVA) and differential scanning calorimetry (DSC) were used to study the effect of rice bran dietary fiber extract on gelatinization and retrogradation of wheat flour. The addition of rice bran dietary fiber extracts from various heat treated bran into wheat flour caused to increase the pasting temperature, peak viscosity and final viscosity of RVA measurements. For gelatinization measured with DSC, mixtures of wheat flour and rice bran dietary fiber extract had slightly higher To (onset temperature) and Tp (peak temperature) values than those of control (wheat flour), and wheat flour/defatted rice bran dietary fiber extract mixture had the lowest enthalpy value. In comparison with gelatinization, the retrogradation endotherm of mixtures stored at $4^{\circ}C$ up to 4 weeks occurred at about $20^{\circ}C$ lower temperatures than gelatinization endotherm with broader shape and well-defined thermograms with storage time. The retrogradation of wheat flour was retarded greatly by addition of rice bran dietary fiber extract, and there was no big difference between 5% and 10% additions.

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.360-365
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• 1996

To investigate the presence of brassinosteroids in rice bran and pㅐlished rice, they were extracted with MeOH. The extracts were purified through sequential procedure of solvent fractionation, silica gel adsorption chromatography, Sephadex LH-20 column chromatography and charcoal adsorption chromatography. The activity of brassinosteroids was monitored by the rice inclination test and its presence was confirmed in each purification step. The purified active components were further separated by TLC and HPLC. Brassinosteroids in active fractions of rice bran were identified as castasterone and teasterone by HPLC. We acknowledge that our work is probably the first report of brassinosteroids in mature seeds of rice The more amount of brassinosteroids was confirmed in rice bran than polished rice. The contents of castasterone and teasterone which were identified in rice bran were 0.15 ng/g and 0.37 ng/g, respectively.