• Korean Journal of Environmental Agriculture
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• v.34 no.2
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• pp.98-104
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• 2015

BACKGROUND: ${\gamma}$-Oryzanol, a mixture of ferulic acid esters of triterpene alcohols and sterols, are a nutritionally important group of rice secondary metabolites. The ${\gamma}$-Oryzanol content and composition were found to vary with enviromental factors such as growth temperature, varietal origin, and cultivation method. Therefore, the effect of green manure treatments will be also be an important factor in their content. METHODS AND RESULTS: The ${\gamma}$-Oryzanols extracted using dichloromethane/methanol were analyzed equipped liquid chromatography with a diode array detector. A total of ten components of ${\gamma}$-oryzanol including ${\Delta}7$-stigmastenyl ferulate were isolated of which, cycloartenyl ferulate, 24-methylenecycloartanyl ferulate, campesteryl ferulate and sitosteryl ferulate were identified as the major components in Korean rice variety, Unkwang. The ${\gamma}$-oryzanol content in rice, in the presence of nitrogen fertilization using green manure was similar to conventional nitrogen fertilization, but was higher than the control(no fertilizations). The ${\gamma}$-oryzanol ontent in rice, in the presence of hairy vetch as green manure crop was the highest compared to other crops (opium-poppy, crimson clover, cornflower). As a result of PLS-DA using SIMCA 11.0 ver. as multivariate analysis program on the basis of total data, in all samples, the specific pattern and cluster of ${\gamma}$-oryzanol scores according to green manure crops and conditions were confirmed with possible distinguishing nitrogen effects. CONCLUSION: The nitrogen contained in the green manure crops is considered to play a major role in the formation of ${\gamma}$-oryzanol. Hairy vetch which contains higher nitrogen increased the concentration of ${\gamma}$-oryzanol in rice.

• Journal of Food Hygiene and Safety
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• v.23 no.1
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• pp.85-89
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• 2008

The oxidative stability of refrigerated precooked pork patties containing commercial ${\gamma}$-oryzanoland ${\alpha}$-tocopherol was evaluated. Precooked pork patties containing either ${\gamma}$-oryzanolor ${\alpha}$-tocopherol showed higher oxidative stability (p<0.05) during storage at $4^{\circ}C$ than did the precooked pork patties without the additives (control). The thiobarbituric acid-reactive substances (TBARs) values and warmed-over flavor (WOF) of the precooked pork patties containing ${\gamma}$-oryzanolor ${\alpha}$-tocopherol were lower (p<0.05) than those of the control during refrigerated storage (0, 1, 4, and 8 days). The correlation between TBARs and WOF values was significant (p<0.05). 7-Ketocholesterol content was lower (p<0.05) than those of the control during refrigerated storage (0, 6, 12, 18, and 24 days). The correlation between TBARs values and 7-ketocholesterol content was also significant (p<0.05).

• Preventive Nutrition and Food Science
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• v.15 no.2
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• pp.113-119
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• 2010

The aim of this study was to investigate changes in 7 nutritional components (fatty acid, protein, fat, ash, total dietary fiber (TDF), $\gamma$-aminobutyric acid (GABA), and $\gamma$-oryzanol) of paddy rice (PR) and brown rice (BR) throughout the germination process, as measured at different shoot lengths (10 mm, 20 mm, and 30 mm). With the increase of shoot length, the nutritional components' concentrations increased, as compared to the concentrations measured before germination. Moreover, BR exhibited higher GABA, $\gamma$-oryzanol, and protein than PR. Among the components, TDF, GABA, and $\gamma$-oryzanol showed significant concentration differences throughout germination, while the others exhibited only slight variations. In particular, GABA and $\gamma$-oryzanol were predominantly increased in grains of 10 mm shoot length. These compounds might prove to be important factors from germinated rice. Additionally, the germinated cultivar 'Keunnun' might also prove to be a very important food source, owing to its high GABA and $\gamma$-oryzanol contents. These results suggest that variations in nutritional components related to the increase of shoot length may prove to be important when considering the beneficial aspects of rice on human health.

• Journal of Food Hygiene and Safety
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• v.23 no.1
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• pp.1-5
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• 2008

The inhibition of cholesterol autoxidation by commercial ${\gamma}$-Oryzanol (0, 50, 100, and 300 ppm) was studied in an aqueous model system for 20 h at pH 5.5 and $80^{\circ}C$. The inhibition effectiveness of the commercial ${\gamma}$-Oryzanol was followed by the retention of cholesterol and the formation of C-7 oxidized cholesterol derivatives (OCDs). Changes in the amount of ${\gamma}$-Oryzanol in the aqueous system were determined during cholesterol autoxidation. A method to detect the levels of 7-ketocholesterol, $7{\alpha}$-hydroxycholesterol and $7{\beta}$-hydroxycholesterol in an aqueous model system with ${\gamma}$-Oryzanol was developed by using the hexane-ethyl acetate extraction system and high-performance liquid chromatography. Results showed that the levels of C-7 OCDs in an aqueous dispersion containing 300 ppm of ${\gamma}$-Oryzanol were not significantly (p>0.05) increased, when compared to other treatments (0, 50, and 100 ppm), during the accelerated cholesterol oxidation.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.4
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• pp.275-283
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• 2014

The ${\gamma}$-oryzanol, ferulic acid esters, which are well-known for their function on cholesterol lowering and prevention of inflammation, diabetes and cancer, are found in the seeds of cereal crops such as rice, corn, wheat and rye. Among them, rice has been reported to contain the highest ferulic acid esters. Since rice cultivation with green manure as a N source is an environmental friendly agricultural practice, it is necessary to identify and quantify as well as evaluate the variations in these compounds in rice samples as affected by different green manure conditions. A total of ten components of ${\gamma}$-oryzanol were isolated and cycloartenyl ferulate, 24-methylenecycloartanyl ferulate, campesteryl ferulate and sitosteryl ferulate were identified as the major components in Korean rice cultivars, 'Unkwang' and 'Hopum'. Comparing the ${\gamma}$-oryzanol contents of these varieties, 'Unkwang' showed clearly similar pattern with conventional type. With the PLS-DA (partial least squares of discriminant analysis) using SIMCA 11.0 ver., the specific pattern and cluster of ${\gamma}$-oryzanol scores with green manure conditions were confirmed, and thus distinguishing green manure effects were possible.

• Food Science and Biotechnology
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• v.18 no.6
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• pp.1398-1403
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• 2009

Present study deals with variations of physicochemicals including $\gamma$-aminobutyric acid (GABA), $\gamma$-oryzanol, free sugar, lipoxygenase activity, fat acidity, and germination rate from Korean brown rice cultivars. With increase of storage time and temperature, GABA, $\gamma$-oryzanol, lipoxygenase activity, and fat acidity increased, whereas free sugar and germination rate was reduced. Among cultivars, 'Gopumbyeo' exhibited the highest contents in GABA and $\gamma$-oryzanol during 12 weeks storage at $25^{\circ}C$ (GABA: $28.6{\pm}5.6{\rightarrow}170.4{\pm}4.6\;mg/100\;g$, $\gamma$-oryzanol: $6.1{\pm}0.7{\rightarrow}6.7{\pm}0.4\;mg/g$) and 'Ilpumbyeo' significantly decreased in free sugar during 12 weeks storage at $10^{\circ}C$ ($1,423.7{\rightarrow}1,058.4\;mg/100\;g$). Moreover, 'Taebongbyeo' exhibited the highest quality owing to low lipoxygenase activity, low fat acidity, and high germination rate. In free sugar compositions, sucrose exhibited the highest content (>70%), followed by fructose (>7%), raffinose (>5%), glucose (>3%), and maltose (>2%) during storage. Based on our results, changes of physicochemicals in stored brown rice may be important information in processing food and functional properties.

• Korean Journal of Food Science and Technology
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• v.32 no.2
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• pp.317-322
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• 2000

This study examined the effect of nitrogen$(N_2)$ gas packing and ${\gamma}-oryzanol$ treatment on the shelf life of Yukwa(Korean traditional snack). Yukwa were stored with $N_2$ gas packing(AN), $N_2$ gas packing with ${\gamma}-oryzanol$ treatment(ANA), and PE film packing with air(PE) for 20 days at $60^{\circ}C$. They were evaluated by POV, AV, conjugated diene, hexanal, color and sensory characteristics. The POV, AV and conjugated diene content increased abruptly in PE and AN, but increased slowly in ANA with prolonged storage. Higher sensory scores for Yukwa were found in ANA as compared to those in PE and AN. Hexanal content, yellowness and redness in AN were higher than those in ANA and PE. The moisture content, which is supposed to be related with browning of Yukwa, was 3 times higher in AN than that in PE. Oxygen content of each Yukwa pack, even in $N_2$ gas packing, increased remarkably as storage period increased because their highly porous, fragile and syrup-coated structure resulted in incomplete degassing before $N_2$ gas was flushed into package. Consequently, $N_2$ gas packing was inefficient, but $N_2$ gas packing combined with antioxidant(such as ${\gamma}-oryzanol$) treatment was effective for the extension of shelf life of Yukwa.

• Food Science and Preservation
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• v.17 no.2
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• pp.281-289
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• 2010

We determined the optimum ethanolic conditions for extraction of $\gamma$-oryzanol and other functional components from rice bran, using response surface methodology (RSM). A central composite design was used to investigate the effects of the independent variables of solvent ratio ($X_1$), extraction temperature ($X_2$), and extraction time ($X_3$), on dependent variables including yield ($Y_1$), total phenolic content ($Y_2$), electron-donating activity ($Y_3$), ferulic acid level ($Y_4$), and $\gamma$-oryzanol concentration ($Y_5$). Solvent ratio and extraction temperature were the most important factors in extraction. The maximum yield was at 22.56 mL/g ($X_1$), 78.19C ($X_2$), and 522.15 min ($X_3$), at the saddle point. Total phenolic levels were little affected by solvent ratio or extraction temperature. The maximum concentration of extracted total phenolics was 90.78mg GAE/100 g at 21.26 mL/g, $94.65^{\circ}C$, and 567.97 min. A maximum electron-donating ability of 54.72% was obtained with the parameters 20.20 mL/g,$81.89^{\circ}C$, and 701.87 min, at the highest point. The maximum level of ferulic acid components was 210.47 mg/100g at 5.22 mL/g, $79.66^{\circ}C$, and 575.24 min. In addition, the maximum $\gamma$-oryzanol concentration was 660.39 mg/100g at 5.10 mL/g, $81.83^{\circ}C$, and 587.39 min. The optimum extraction conditions were a solvent ratio of 10.45 mL/g, $80^{\circ}C$ extraction temperature, and 535 min extraction time. Predicted extraction levels under optimized conditions were in line with experimental values.

• Korean Journal of Food Science and Technology
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• v.49 no.1
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• pp.110-116
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• 2017

${\gamma}-Oryzanol-loaded$ calcium-pectin micro- and nanocapsules were prepared by ionic gelation to improve oxidation stability and the effect of particle size on capsule properties was investigated. The physical properties were influenced by preparation conditions such as concentrations of pectin, $CaCl_2$, ${\gamma}-oryzanol$, and hardening time. Particle sizes of micro- and nanocapsules that showed the maximum encapsulation efficiency and sustained release were $2.27{\pm}0.02mm$ and $347.7{\pm}58.1nm$, respectively. Microcapsules showed higher encapsulation efficiency ($50.73{\pm}1.98%$) than nanocapsules ($17.70{\pm}2.04%$), while nanocapsules showed more sustained release and higher stability than microcapsules. Release of ${\gamma}-oryzanol$ from both microand nanocapsules, which was low in gastric environments and promoted in intestinal environments, showed suitable characteristics for oral administration. Furthermore, antioxidant activity of ${\gamma}-oryzanol$ against autoxidation of linoleic acid was prolonged by both micro- and nanoencapsulation in a ferric thiocyanate test. Therefore, micro- and nanoencapsulation using pectin can be effective for improving biodelivery, stability, and antioxidant activity of ${\gamma}-oryzanol$.

• Journal of the Korean Society of Food Culture
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• v.37 no.1
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• pp.81-89
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• 2022

This study aimed to evaluate the changes in the content of functional components and antioxidant activity of rice and barley according to the milling process used. A considerable amount of γ-oryzanol was observed in unmilled rice and barley. However, γ-oryzanol was not detected in the rice and barley after the milling process. The highest content of γ-aminobutyric acid (GABA) was observed in the unmilled Keunalbori-1-ho barley. The contents of biotin in all samples also decreased in the milled grains compared to the unmilled grains. The highest content of total polyphenols and flavonoids was observed in the Heuksujeongchal barley, and the highest radical scavenging activity was also found in this grain. The milling process led to a decrease in the content of functional components, including γ-oryzanol, GABA, biotin, polyphenols, and flavonoids in both rice and barley. These results may be useful in the development of processed foods using cereal grains.