• Korean Journal of Environmental Agriculture
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• v.30 no.2
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• pp.111-117
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• 2011

BACKGROUND: Anthocyanins have been recognized as health-enhancing substances due to their antioxidant activity, anti-inflammatory, anticancer, and hypoglycemic effects. The objective was to identify anthocyanins-rich rice grains for the development of functional foods and/or functional food colorants METHODS AND RESULTS: Rice grains of one black and three red-hulled rice varieties were extracted with acidified 80% aqueous methanol. The antioxidant activity of the methanolic extracts was screened on TLC plates and in an in vitro assay using DPPH (1, 1-diphenyl-2-picrylhydrazyl) as a free radical source. Red-hulled rice varieties exhibited higher antioxidant activity (88%, 1 mg/mL) than black rice (67%, 1 mg/mL). Among the red-hulled varieties tested, rice variety SSALBYEO54 (901452) was the most active (72%, 0.5 mg/mL). Rice extracted anthocyanin compounds were analyzed by HPLC-DAD-FLD and LC-MS/MS. Red-hulled varieties comprised cyanidin-3-glucoside in addition to ferulic acid esters, apigenin and kaempferol glycosides. CONCLUSION(s): Anthocyanins identified in the black rice variety were cyanidin-7-O-galactoside, cyanidin-3-Oglucoside, cyanidin-3'-O-glucoside, cyanidin-5-O-glucoside, cyanidin-3, 7-O-diglucoside, cyanidin-3, 5-O-diglucoside and peonidin-4'-O-glucoside. The results of this study show that the black rice (IT212512) and red-hulled rice variety SSALBYEO54 (901452) contain notable antioxidant activity for potential use in nutraceutical or functional food formulations.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.5
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• pp.451-457
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• 2006

The purpose of this study is to measure fundamental data required for the prediction of rice quality and to develop regression models to predict protein, amylose, moisture and fatty acid contents, and Toyo taste meter value (TTMV) of brown and polished rice from hulled rice NIR spectra. NIR spectra of hulled rice measured in transmittance mode (850-1050 nm) and in reflectance mode (400-2500 nm) were used to predicted chemical compositions of brown rice and polished rice. For most chemicals, the transmittance spectra could provide better calibration results than the reflectance ones. Beside the Toyo taste meter value (TTMV), the hulled rice spectra could predict chemical contents with the determination coefficients higher than 0.8. Spectra of hulled rice measured in transmittance mode could be used for the prediction of chemical compositions in brown rice and polished rice precisely. However, taste value of polished rice was a constituent that was hardly to be predicted.

• Journal of Microbiology and Biotechnology
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• v.32 no.3
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• pp.317-323
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• 2022

Solid-state fermentation using hulled barley was carried out to produce enzymes and β-glucan. The one-factor-at-a-time experiments were carried out to determine the optimal composition of the basal medium. The modified synthetic medium composition in liquid-state fermentation was determined to be 70 g/l hulled barley, 0 g/l rice bran, 5 g/l soytone, and 6 g/l ascorbic acid. Optimal pretreatment conditions of hulled barley by solid-state fermentation were evaluated in terms of maximum production of fungal biomass, amylase, protease, and β-glucan, which were 1.26 mg/g, 31310.34 U/g, 2614.95 U/g, and 14.6% (w/w), respectively, at 60 min of pretreatment condition. Thus, the solid-state fermentation process was found to enhance the overall fermentation yields of hulled barley to produce high amounts of enzymes and β-glucan.

• The Korean Journal of Pesticide Science
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• v.14 no.1
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• pp.16-20
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• 2010

Thiosultap, a nereistoxin analog insecticide, registered in China has been used to control selected beetles and Lepidopteran pests on rice, vegetables and fruit trees. Although domestic use of thiosultap is not permitted, it is needed to monitor this insecticide from imported crops because that has been used on crops in many foreign countries, especially China. Thiosultap in hulled rice was determined as nereistoxin derived in basic condition by GC-FPD. This method accomplished ion-associated liquid-liquid partitioning for cleanup, and limit of quantification and linearity performed by the established method were 0.05 mg $kg^{-1}$ and 0.995$(r^2)$. The recoveries performed by control hulled rice fortified with thiosultap at 0.5 and 2.5 mg $kg^{-1}$ were $96.1{\pm}7.9\sim100.8{\pm}6.1%$.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.926-936
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• 1996

Field hulling of high-moisture paddy followed by brown rice drying offers many advantages over the present paddy harvesting and drying offers many advantages over the present paddy harvesting and drying system. We did a preliminary study of the parameters for efficient hulling of high-moisture paddy using the IRRI Centrifugal Huller and two India rice varieties. Hulling capacity , hulling efficiency , brown rice recovery and percent whole bown rice were generally best at the impeller peripheral speed of 44m/s. A second pass through the huller increased hulling capacity , brown rice revery and hulling efficiency, but reduced percent whole brown rice. To solve this , we recommed separation of paddy after hulling and aspiration such that only unhulled and partially -hulled grains will be fed back to the huller. Paddy at even 23% m.c. could be effectively hulled by the impeller-type huller , but the results were generally better at 14 to 17% m.c. Only in percent whole brown rice did the 17 to 23% m.c. range performed better than that of 14% m.c. Difference invarietal response to hulling was observed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.35-41
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• 2006

This study was conducted to establish the post-harvest management system in rice. Harvested hulled rice was gathered into large-scale bag and combine bag, in which the rice quality and the influence on quality change were investigated on various storage periods and moisture contents. Moisture content of hulled rice ranged from 23.7% to 28.8% on different harvest times, which grew lower as harvesting time was delayed. When desiccation was retarded hulled rice in large scale bag was changed in color and emitted an of offensive odor in 3 days and that in combine bag showed similar symptom in 4 days. Inner temperature in large scale bag was changed a lot when the storage period was prolonged and also the moisture content was higher while that in combine bag increased regularly corresponding to the moisture content at the time of harvest. Moisture content of hulled rice stored in large-scale bag increased 2 days after harvest and the more moisture content showed the more increased tendency, while in the case of combine bag the moisture content was not changed much whether the hulled rice contained low or high moisture content in harvesting. As desiccation was delayed fatty acid increased much more in large-scale bag than in combine bag even though protein and amylose contentwere not changed. As desiccation was delayed more and hulled rice contained moisture more in harvesting head rice ratio of brown rice decreased and green-kerneled rice and damaged grain ratio increased and quality of milled rice also became deteriorated. As a result, desiccation day to minimize the deterioration of rice quality was estimated 1-2 days in large scale bag and 2-3 days in combine bag after harvesting.

• Korean Journal of Environmental Agriculture
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• v.29 no.3
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• pp.247-256
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• 2010

A high-performance liquid chromatographic (HPLC) method was developed to determine buprofezin residues in hulled rice and fruits. The buprofezin residue was extracted with acetone and the extract was stepwise purified by liquid-liquid partition and Florisil column chromatography. For rice samples, acetonitrile/n-hexane partition was additionally employed to remove nonpolar lipids. Reversed phase HPLC using an octadecylsilyl column was successfully applied to separate buprofezin from sample co-extractives, as detected by ultraviolet absorption at 250 nm. Recovery experiment at the limit of quantitation validated that the proposed method could evidently determine the buprofezin residue at the level of 0.02 mg/kg. Mean recoveries from hulled rice, apple, pear, and persimmon samples fortified at three tenfold levels were in the range of 80.8~85.2%, 89.1~98.4%, 88.8~95.7% and 90.8~96.2%, respectively. Relative standard deviations of the analytical method were all less than 5%, irrespective of sample types. A selected-ion monitoring LC/mass spectrometry with positive electrospray ionization was also provided to sensitively confirm the suspected residue.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.4
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• pp.261-266
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• 2000

This study was to investigate antioxidative activity of rice grain using 1, 1-Diphenyl-2-picrylhydrazyl(DPPH) and thiobarbituric acid (TBA) method and germination ability for screening rice varieties with high antioxidative activities on korean native and foreign rice varieties harvested in 1998 and 1999. The average antioxidative activity of foreign rice varieties (DPPH 63.5% and TBA 55.2%) was significantly higher than that of native rice varieties (DPPH 47.2% and TBA 45.6%) on varieties harvested in 1999. The promptness index (PI) of native rice varieties was higher in stored rices for three months (mean PI=160.7) than that of stored rices for a year (mean PI=141.6). On the other hand, the PI of foreign rice varieties was higher in stored rices stored for a year (mean PI=176.7) than that of stored rices for three months (mean PI=157.5). Varieties with high redness of hulled rice (a-value) showed significant lipid peroxidation inhibitory activity to DPPH in a stored rices for a year (r=${0.5744}^**$) and stored rices for three months (r=${0.5630}^**$) . These results indicate that the pigments of hulled rice varieties may play important antioxidative roles and colored rice varieties with higher antioxidative potentials can be developed and also may provide information with rice breeder to breed rice variety with a high antioxidative activity for a rapid screening of a small amounts of a large number of samples using color value.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.3
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• pp.244-250
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• 2008

The purpose of this study was to measure fundamental data required for the prediction of milling ratios, and to develop regression models to predict the head rice ratio of milled rice using NIR spectra of hulled rice. A total of 81 rice samples used in this study were collected from Jeongeup, Jeonbuk province in 2006. NIR spectra were measured using one mode of measurement, reflection. The reflectance spectra were measured in the wavelength region of 400-2500 nm with an NIR spectrophotometer "NIRSystems 6500" (Foss, Silverspring, USA). Calibration equations were developed by the modified partial least squares (MPLS), partial least squares (PLS), and principal components regression (PCR). Math treatments were 1-4-4-1, 1-10-10-1, 2-4-4-1, and 2-10-10-1. The software used was WinISI (Infrasoft International, State College, USA). Automatic head rice production and quality checking system used was "SY2000-AHRPQCS" (Ssangyong, Korea). The calibration was made with the first derivative and the spectrum designated was in 8 nm interval. The determination coefficients of head rice ratios were 0.8353, 0.8416 and 0.5277 for the MPLS, PLS and PCR, respectively. Those obtained with 20 nm interval were 0.8144, 0.8354 and 0.6908 for the MPLS, PLS and PCR, respectively. The calibration was made with second derivative that spectrum designated was 8 nm in interval. The determination coefficients of head rice ratios were 0.7994, 0.8017 and 0.4473 for the MPLS, PLS and PCR, respectively. Those with 20 nm interval were 0.8004, 0.8493 and 0.6609 for the MPLS, PLS and PCR, respectively. These results indicate that the accuracy of determination coefficient for MPLS and PLS is higher than that of PCR.

• Korean Journal of Food Science and Technology
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• v.40 no.6
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• pp.603-610
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• 2008

The principal objective of current study was to evaluate the potential of near infrared reflectance spectroscopy (NIRS) as a non-destructive method for the prediction of the amylose and protein contents of un-hulled and brown rice in broad-based calibration models. The average amylose and protein content of 75 rice accessions were 20.3% and 7.1%, respectively. Additionally, the range of amylose and protein content were 16.6-24.5% and 3.8-9.3%, respectively. In total, 79 rice germplasms representing a wide range of chemical characteristics, variable physical properties, and origins were scanned via NIRS for calibration and validation equations. The un-hulled and brown rice samples evidenced distinctly different patterns in a wavelength range from 1,440 nm to 2,400 nm in the original NIR spectra. The optimal performance calibration model could be obtained by MPLS (modified partial least squares) using the first derivative method (1:4:4:1) for un-hulled rice and the second derivative method (2:4:4:1) for brown rice. The correlation coefficients $(r^2)$ and standard error of calibration (SEC) of protein and amylose contents for the un-hulled rice were 0.86, 2.48, and 0.84, 1.13, respectively. The $r^2$ and SEC of protein and amylose content for brown rice were 0.95, 1.09 and 0.94, 0.42, respectively. The results of this study suggest that the NIRS technique could be utilized as a routine procedure for the quantification of protein and amylose contents in large accessions of un-hulled rice germplasms.