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Temperate japonica rice is mainly cultivated in temperate regions. Many temperate japonica varieties have a superior grain quality that is preferred in Northeast Asian countries such as Japan, Korea, and China. The changes in consumers’ preferences in Southeast Asia and Western countries has contributed to increasing the demand for temperate japonica. Most temperate japonica varieties developed in temperate regions typically exhibit extra-early flowering under the short-day conditions in the tropics, which usually results in severely reduced yields. Since 1992, we have been developing temperate japonica varieties that can adapt to tropical environments to meet the increasing demand for temperate japonica rice, having released six varieties in the Philippines. Especially, the yield of one of the temperate japonica varieties, Japonica 7, was comparable to the yields of leading indica varieties in the Philippines. Here, we discuss the current breeding initiatives and future plans for the development of tropical-region-bred temperate japonica rice.

Seeds of 15 diverse rice accessions, representing aus, indica, temperate japonica and tropical japonica subpopulations, were produced under temperate climate conditions in Korea and used for vitamin E analysis and seed storage experiments at 45°C and 10.9% seed moisture content. High γ-tocotrienol was significantly positively correlated with seed longevity. In addition, a high β-tocopherol proportion relative to δ-tocopherol was significantly negatively correlated with seed longevity. Using high-density single-nucleotide polymorphism marker data, DNA haplotype analysis showed clear allelic variations in the region of two S-adenosylmethionine synthetase genes: LOC_Os04g42095 and LOC_Os11g15410, which regulate the conversion of δ-tocopherol into β-tocopherol. Four indica accessions with rare and subpopulation-specific alleles showed a 2.3-fold lower β-/δ-tocopherol ratio compared with accessions from other subpopulations.

Wild relatives of rice in the genus Oryza (composed of 24 species with 11 different genome types) have been significantly contributing to the varietal improvement of rice (Oryza sativa). More than 4000 accessions of wild rice species are available and they are regarded as a “genetic reservoir” for further rice improvement. DNA markers are essential tools in genetic analysis and breeding. To date, genome-wide marker sets for wild rice species have not been well established and this is one of the major difficulties for the efficient use of wild germplasm. Here, we developed 541 genome-wide InDel markers for the discrimination of alleles between the cultivated species O. sativa and the other seven AA-genome species by positional multiple sequence alignments among five AA-genome species with four rice varieties. The newly developed markers were tested by PCR-agarose gel analysis of 24 accessions from eight AA genome species (three accessions per species) along with two representative cultivars (O. sativa subsp. indica cv. IR24 and subsp. japonica cv. Nipponbare). Marker polymorphism was validated for 475 markers. The number of polymorphic markers between IR24 and each species (three accessions) ranged from 338 (versus O. rufipogon) to 416 (versus O. longistaminata) and the values in comparison with Nipponbare ranged from 179 (versus O. glaberrima) to 323 (versus O. glumaepatula). These marker sets will be useful for genetic studies and use of the AA-genome wild rice species.

This study was carried out to compare the physiochemical properties and quality characteristics of porridge made from different Korean rice varieties, including high yield tongil-type rice. The rice varieties used in this study were 4 tongil-type (Areum, Namcheon, Hanareum3, Hanareum4) and 5 japonica-type rices (Unkwang, Daebo, Goami4, Dodamssal and Hwaseonchal). The protein and amylose contents of the varieties ranged from 6.0% (Namcheon) to 7.3% (Hanareum3) and from 5.0% (Hwaseonchal) to 42.8% (Dodamssal). Compared to the other varieties, Hwaseonchal and Dodamssal had low final and setback viscosity values in the rapid-visco analyzer test. The color value of the porridge ranged between 52.90 and 71.12 for the L value, -2.06 and -1.01 for the a value, and -5.59 and -2.62 for the b value. SEM images revealed distinct differences in the endosperm structure of rice varieties as well as the porridge. Furthermore, porridge made from Hwaseonchal rice had the highest spreadability, followed by porridge made from others non-glutinous rice varieties, Goami4 rice, and Dodamssal rice. The results of this study suggested that rice varieties with different amylose contents could be effectively used to control the viscosity of rice porridge. In laboratory experiments, the sensory test did not indicate significant differences except for the mouthfeel. The mouthfeel of the porridge depended on the amylose content of rice. This study suggested that tongil-type rice variety such as Hanareum4 could be substituted with Japonica type rice for making porridge.

Fatty acid methyl ester (FAME) were synthesized via in situ lipase-catalyzed transesterification in rice bran without additional catalyst. With this method, FAME were synthesized directly from oil in rice bran by simply adding methanol, with the aid of rice bran lipase already existing in rice bran. The effects of temperature, molar ratio (oil in rice bran to methanol), and water content of the rice bran were investigated. The yield of FAME and the free fatty acid content were monitored as a function of reaction time. The optimum conditions were a temperature of 40 °C, a molar ratio of 1:6, and a water content of 12%. Under the optimum conditions, the FAME yield of 83.4 wt% was obtained after 12 days. To further increase the FAME yield, the transesterification was repeated using the rice bran obtained from the first transesterification. The oils in rice bran that could be converted to FAME were completely transformed throughout the repeated transesterification.

Vitamin E (tocols) is a key metabolite for efficient scavenging of lipid peroxy radicals that cause membrane breakdown during seed ageing. However, in rice, this hypothesis has been tested for very few lines only and without considering intraspecific variation in genomic structure. Here, we present a correlation study between tocols and seed longevity using a diverse rice panel. Seeds of 20 rice accessions held in the International Rice Genebank at the International Rice Research Institute, representing Aus, Basmati/Sadri, Indica, temperate Japonica and tropical Japonica variety groups, were used for tocols analysis (quantification of α-, β-, γ- and δ-tocopherol/tocotrienol by ultra-performance liquid chromatography) and storage experiments at 45°C and 10.9% seed moisture content. To examine the effects of DNA-haplotype on the phenotype, the 700 K high-density single-nucleotide polymorphism marker dataset was utilized. Both seed longevity (time for viability to fall to 50%; p50) and tocols content varied across variety groups related to the heterogeneity in the genetic architecture. Among eight types of tocol homologues, α-tocopherol and γ-tocotrienol were significantly correlated with p50 (negatively and positively, respectively). While temperate Japonica varieties were most abundant in α-tocopherol, Indica varieties recorded 1.3- to 1.7-fold higher γ-tocotrienol than those of other groups. We conclude that the specific ratio of tocol homologues rather than total tocols content plays an important role in the seed longevity mechanism.

Producing good-quality, fine rice flour is more difficult than wheat flour because the rice grain is harder. The non-glutinous Japonica-type variety Seolgaeng, derived from N-methyl-N-nitrosourea (MNU) mutagenesis, and four other varieties, representing a range of amylose contents, were evaluated in this study. Dry-milled Seolgaeng rice flour exhibited an average particle size that is

The physicochemical properties and in-vitro digestibility of extruded rice noodles with different amylose contents were characterized from a rheological point of view. Thermo-mechanical measurements showed that the rice flour with higher amylose contents exhibited greater stability to dual-mixing and higher degrees of starch gelatinization and retrogradation. In addition, greater elastic properties were clearly observed in the high amylose rice samples. The use of high amylose rice flour produced noodles with a harder texture, consequently contributing to reduced cooking loss. Furthermore, the rheological changes of extruded rice noodles were monitored in real time during the in-vitro starch digestion. The rice noodle digesta with higher amylose contents exhibited greater viscosities throughout the simulated oral-gastric-intestinal digestion steps. The flow behaviors of the rice noodle digesta consisted of the Power-law region and infinite shear plateau that were satisfactorily characterized by the Sisko model (R 2 > 0.99).

This study was conducted the comparative analysis on quality and rice bread process suitability properties by four particle size classification of dry-milled flours for four rice varieties. Dry-milled rice flours were prepared by dry milling and classified according to particle size using 100, 150, 200, and 250 mesh sieves. The mean particle size by four particle size classification of 60 ~ 100 mesh, 100 ~ 150 mesh, 150 ~ 200 mesh, 200 ~ 250 mesh exhibited 118.9 μm, 87.4 μm, 65.3 μm, 46.1 μm, respectively. The particle size of dry-milled rice flours was the finer, the damaged starch content was the higher (r = − 0.570*). The particle size also had significant negative correlation with the water absorption index (r = − 0.533*, r = − 0.593*), and water solubility index (r = − 0.857**, r = − 0.584*). Dry-milled rice flours with particle size of 60 ~ 70 μm, passed through 150 and 200 mesh sieves exhibited the highest specific volume of rice bread. Whereas, the dry-milled rice flour with finer particle size above 200 mesh showed the lowest specific volume of rice bread. These results will be applied as a quality standard to aid in the selection of the most suitable dry-milled rice flour for baking.

Synthesis of a fatty acid ethyl ester via the lipase-catalyzed transesterification of acid oil and ethanol was investigated in a continuous reactor. Lipozyme TL IM was employed as the immobilized lipase. This immobilized lipase derived from Thermomyces lanuginosus was purchased from Novozymes (Seoul, Korea). The acid oil was prepared by the acidification of soapstock formed as a by-product during the refining of rice bran oil. The parameters investigated were water content, temperature, and molar ratio of substrates. The relative activity of Lipozyme TL IM was assessed during the repeated use of the immobilized lipase. The water content of the substrate had a considerable effect on the yield and the optimum water content was 4 %. The optimum temperature and molar ratio of acid oil to ethanol were 20 °C and 1:4, respectively. The maximum yield of approximately 92 % was achieved under the optimum conditions. The corresponding compositions were 92 % fatty acid ethyl esters, 3 % fatty acids, and 5 % acylglycerols. When glycerol formed during the reaction was removed by intermittent washing with ethanol, the relative activity of lipase was maintained over 82 % for a total usage of 27 cycles. For a mean residence time of 4 h, the half-life times of Lipozyme TL IM on the control (unwashed) and treatment (washed) were 39 and 45 cycles, respectively.

Adaptation of temperate japonica rice varieties to tropical regions is impeded by extremely early flowering probably due to photoperiod change from long to short. However, constant breeding efforts led to development of temperate japonica varieties adapted to tropical/subtropical regions, but the genetic factor underlying this is still elusive. We analyzed the 45 diverse rice accessions and 12 tropical-adapted temperate japonica lines for the allele types of seven major flowering genes Hd1, OsPPR37, DTH8, Ghd7, Ehd1, RFT1, and Hd3a and flowering time under three different field conditions in temperate and tropical locations. The accessions originated from the tropical/subtropical regions preferred the non-functional alleles of Hd1 and not other flowering genes. The genetic effect analysis of each gene showed that only the functional Hd1 caused early flowering in the tropical location. All 12 temperate japonica breeding lines adapted to the tropics possessed the loss-of-function alleles of Hd1 with no change of other flowering genes compared to common Korean temperate japonica varieties. A phylogenetic analysis using 2,918 SNP data points revealed that the genome status of the 12 breeding lines were very similar to Korean temperate japonica varieties. These results indicate that the functional Hd1 alleles of temperate japonica varieties induced extremely early flowering in the tropics and the non-functional hd1 alleles brought about the adaptation of temperate japonica rice to tropical regions.

The in-vitro starch digestibility of white and brown rice flours was continuously characterized from a rheological point of view. Specifically, the in-vitro viscosities of the rice digesta samples were monitored under simulated oral, gastric, and intestinal conditions. A trend of decreasing viscosities in all the digesta samples was observed during the in-vitro digestion. After cooking, the brown rice sample exhibited lower viscosity than that of the white rice flour due to the presence of more non-starch components. A similar tendency was observed during the simulated oral and gastric digestions. However, the viscosity crossover between the white and brown rice samples was observed during intestinal digestion. In addition, the amount of glucose released from the brown rice flour was significantly lower than that from the white rice flour. Thus, the slower rate of starch hydrolysis in the brown rice flour could be related to its in-vitro rheological behaviors.

UNLABELLED Morphological, viscoelastic, hydration, pasting, and thermal properties of starches separated from 10 different rice cultivars were investigated. Upon gelatinization, the G' values of the rice starch pastes ranged from 37.4 to 2057 Pa at 25 °C, and remarkably, the magnitude depended on the starch varieties. The rheological behavior during gelatinization upon heating brought out differences in onset in G' and degree of steepness. The cultivar with high amylose content (Goami) showed the lowest critical strain (γ(c)), whereas the cultivars with low amylose content (Boseokchal and Shinseonchal) possessed the highest γ(c). The amylose content in rice starches affected their pasting properties; the sample possessing the highest amylose content showed the highest final viscosity and setback value, whereas waxy starch samples displayed low final viscosity and setback value. The onset gelatinization temperatures of the starches from 10 rice cultivars ranged between 57.9 and 64.4 °C. The amylose content was fairly correlated to hydration and pasting properties of rice starches but did not correlate well with viscoelastic and thermal characteristics. The combined analysis of hydration, pasting, viscoelastic, and thermal data of the rice starches is useful in fully understanding their behavior and in addressing the processability for food applications. PRACTICAL APPLICATION Rice flour has potential applications in various food products. The physicochemical properties of rice flour are dependent on its variety, which affects the quality of the final products. In this study, the combined analysis including hydration, pasting, viscoelastic, and thermal properties of rice flour could afford information for preparing a particular product such as bread and noodle.

Summary The effect of three different rice varieties with different starch shapes (Seolgaeng (SG), round starch structure; Samkwang (SK), polygonal starch structure and Boramchan (BRC), polygonal starch structure) on rice flour characteristics and gluten-free bread baking quality was investigated. Rice flours were produced by dry milling and passed through a 200 mesh sieve. Electron microscopy revealed that the structure of SG grains, with round starch granules, possessed larger void spaces than SK and BRC, composed of polygonal starch granules. For this reason, SG grain had low grain hardness and consequently, it was milled to a fine flour with low damaged starch content. The thermo-mechanical properties were determined by Mixolab, which revealed that SG was gelatinised rapidly and maintained high viscosity after gelatinisation. These characteristics gave SG flour the ability to build up bread structure without gluten. Specific volume and crumb hardness of gluten-free rice breads made of SG, SK and BRC flours were 3.37, 3.11 and 2.12 mL g−1 and 2.61, 2.76 and 6.46 N, respectively. The SG flour with round starch structure is appropriate for making gluten-free rice breads.

This study investigated the effects of the particle size distribution of rice flour on the quality of a gluten-free ricebread. Seolgaeng (SG), a type of japonica cultivar, was milled for producing rice flours and then screened using100, 200, and 300 mesh sieves for sorting the rice flour. Rice flour characteristics including: amylose content, dam-aged starch content, moisture content, average particle size and particle morphology were examined as well as thegluten-free rice bread characteristics: specific volume, crumb hardness, and appearance. The SG rice particlesshowed low starch damage compared to those milled of common rice cultivars since the starch granules of SG wererelatively round shaped. The specific volumes of gluten-free rice breads prepared with the flours passed through100, 200 and 300 mesh sieves were 3.19, 3.36 and 1.41mL/g respectively. In this study, the gluten-free rice breadprepared from the flour passed through the 200mesh sieve showed the best quality since the texture of its crumbswere relatively soft and the color of its crust appeared good.

Goami2, Goami3 and Goami4 were identified as fiber-rich rice cultivars which were developed by mutation breeding with Ilpum. The purpose of this study was to develop a method for producing Makgeolli with the fiber-rich rice cultivars, Goami2, Goami3, Goami4, and to investigate the characteristics of Makgeolli during the fermentation process. Makgeolli was produced herein by fermentation steamed rice (SR), raw rice flour (RF), and steamed rice flour (SF) from Goami2, Goami3, Goami4, Ilpum and Sealgaeng rice cultivars. The physicochemical characteristics including alcohol and sugar content, pH, total acidity, TDF (total dietary fiber), and color of the Makgeolli samples were analyzed. Makgeolli produced with Ilpum and Sealgaeng showed satisfactory fermention characteristics in alcohol and sugar content when SR, RF and SF were used. In the case of Goami2, Goami3, and Goami4, the use of SF resulted in 17.2~20.1% alcohol content, whereasonly 10% alcohol was produced by SR. The sugar contents in the SF-makgeolli samples were also higher (9~10 °Brix) than in the SR-makgeolli (5.35~5.44 °Brix) for Goami2 and Goami4 cultivars. The dietary fiber contents of the Makgeolli samples produced using SF from the fiber-rich rice cultivars were higher (1.35~1.52 g/100 mL) than those produced with Ilpum and Sealgaeng (0.74~0.87 g/100 mL). From these results, it may be suggested that SF would be an appropriate material to brew Makgeolli using fiber-rich rice cultivars to obtain better physicochemical and functional qualities. Key words: Goami2, Goami3, Goami4, total dietary fiber, Makgeolli, rice flour

Rice bran oil (RBO) is a good source of several commercially important bioactive phytochemicals, such as tocols (i.e. tocopherols and tocotrienols) and ferulic esters of sterols (i.e. γ-oryzanol). The aims of the present study were to examine the effects of different pressure and temperature combinations on the fractional extraction of RBO using supercritical carbon dioxide (SC-CO2) and to assess the levels of tocols homologues and γ-oryzanol components in the resulting oil fractions. Fractional extraction of rice bran oil was performed using SC-CO2 at either 27.6 or 41.4 MPa and either 40 or 60°C. The effects of the four different pressure and temperature combinations on the levels of seven tocols homologues (α-, β-, γ- and δ-tocopherol and α-, γ- and δ-tocotrienol) and the four major components of γ-oryzanol in the resulting oil fractions were investigated. Superior extraction efficiency was obtained using the higher pressure of 41.4 MPa. The tocols (particularly α-tocopherol and α-tocotrienol) were recovered early in the extraction process, while the γ-oryzanol compounds were obtained in the later stages. With regard to SC-CO2 extraction, tocols are more soluble than γ-oryzanol components, α-tocopherol is the most soluble of the tocols and the four γ-oryzanol components all have similar solubilities. Valuable data on solubilities of tocols homologues in SC-CO2 were provided from present study.

The extraction yield, total phenolics content, antioxidant activity, cancer cell growth inhibition (A549 and MCF 7), and lung cancer cell (A549) viability of red rice and black rice were investigated, to evaluate the functional properties of colored rice. The extraction yields and the total phenolics contents of the rice cultivars were Heugseol > Heugkwang > Hongjinju > Jeogjinju > Ilpum. Also, the DPPH radical scavenging activity of the black rice did not differ from that of the red rice, whereas its activity among its cultivars was Jeogjinju > Heugseol > Heugkwang > Hongjinju > Ilpum. The ABTS antioxidant activity of the black rice (Heugkwang, Heugseol) was greater than that of the red rice. The total phenolics was partly attributed to its high antioxidant. On the other hand, the effect of the red rice on the lung cancer cell (A549) viability was higher than that of the black rice. The breast cancer cell (MCF 7) growth inhibition activity of the black rice did not differ from that of the red rice. Our results indicate that the ABTS antioxidant activity of black rice is better than that of red rice, and the lung cancer cell (A549) viability of red rice is better than that of black rice.

The aim of the present study was to examine the effects of different pressure and temperature combinations on the concentrations of tocols homologues, policosanol, phytosterol, and γ-oryzanol in crude rice bran oil (RBO) using supercritical carbon dioxide (SC-CO 2 ). To effectively separate oily substances from bioactive substances, fatty acid ethyl esterification was performed by sulfuric acid or the lipase catalytic method. In sulfuric acid esterification, γtocotrienol content was decreased by ca. 50%, whereas in lipase esterification, γ-tocotrienol content was not decreased. Therefore, lipase catalytic esterification was performed for the fatty acid alkyl esterification of RBO. The fractional extraction of RBO ethyl esters was performed using SC-CO 2 in the condition of 9.62 Mpa, 10.34 MPa, or 11.03 MPa and 45C, 50C, or 55C. During the fractionation of RBO using SC-CO 2 , a little tocols content was extracted with fatty acid ethyl esters, but policosanol and phytosterol were not extracted. Especially, there is a high correlation (R=0.9306) between the density of CO 2 and tocols contents extracted to the fractions. The concentration rates of tocols and phytosterol were the highest in the condition of 55C and 9.62 MPa. Therefore, the lower CO 2 density applied, the more efficient the concentrations of tocols and phytosterol were in this study.

The purpose of this study is to investigate the effect of rice cultivar on the quality of gluten-free rice bread. Three different type of japonica rice cultivars (Seolgaeng, Goami, and Baegjinju) were used in this study. Rice flour was produced by dry milling and using a 200 mesh sieve. Rice bread was prepared using the straight dough method with an addition of hydroxypropyl methylcellulose as a dough improver. Rice bread dough was divided into 170 g and then fermented prior to baking. Gluten-free rice bread prepared using flour from the Seolgaeng cultivar showed the largest volume (446±11.7 mL) and a uniformly distributed pore structure in bread crumbs whose hardness value was 2.66±0.2 N. Rice bread prepared using flour from Goami and Baegjinju cultivars showed rough crumb surface and hard crumb texture. The low damaged starch content (4.5%) and intermediate amylose content (19.3%) of the Seolgaeng cultivar contributed to produce superior qualities such as large volume and soft crumb texture in rice bread.

In this study, we examine the palatability and physicochemical properties of rice in the year, when there was 10% increase in yield compared to normal year due to daily temperature range and sunshine hours. The results of the analysis of rice yield over the last 20 years (1993-2012) showed 10% difference between the yield in 2000, which was normal, and that in 2001. With regard to the crop weather condition during the ripening period in 2001 compared to 2000, the daily range and sunshine hours were higher, but the mean temperature was similar. The rice yield in 2001 was 9.8% higher than that in 2000 due to the increased number of spikelets per panicles and ratio of ripened grain. In terms of chemical traits, protein, Mg, and K contents decreased in 2001 compared to 2000, but amylose content increased. Trough and final viscosity assessed with a Rapid Visco Analyser were significantly higher in 2001 than 2000. The quality of cooked rice was measured through the Toyo Mido Meter Glossiness Value (TGV) instead of a palatability score because a sensory test produces relative comparison values rather than absolute values. The correlation coefficients between the sensory evaluation parameters and the TGV in several rice materials harvested in two years showed a highly significant positive correlation (r=0.81 ** -0.89 ** , n=27-47). TGV was also significantly higher in 2001 than in 2000. The results suggested that the palatability of cooked rice was good in 2001 with about 10% increase in rice yield compared to normal year in 2000 due to daily temperature range and sunshine hours.

This study investigated the changes in the nutraceutical lipid components of brown rice oil after germination. Four different high-yielding cultivars (Dasan1, Segyejinmi, Hanareum1 and Hanareum2) of Korean brown rice were selected and brown rice oil was extracted from each cultivar before and after germination. Free fatty acid, squalene, policosanols, and isomers of phytosterol were analyzed using GC, and isomers of tocols (tocopherol and tocotrienol) and γ-oryzanol were quantified using HPLC from both brown rice oil (BRO) and germinated brown rice oil (GBRO). The contents of phytosterol isomers, campesterol, stigmasterol, and β-sitosterol were increased by 8.3%, 31.6%, 3.3% in GBRO, respectively. Furthermore, the squalene content showed the highest increase of up to 2.4 fold in GBRO compared to BRO. In addition, linoleic and linolenic acid composition increased whereas oleic and palmitic acid decreased in the GRBO. However, the contents of tocols (tocopherol and tocotrienol) in GBRO were lower than those in BRO, and there was no significant difference in policosanol and γ-oryzanol between GBRO and BRO. These results suggest that GBRO has the potential as a healthy and functional source due to its lipid profile on improved lipid metabolism.Key words: germinated brown rice, brown rice oil, nutraceutical lipid, phytosterol, squalene

Phytosteryl ester synthesized with pinolenic acid (PLA) from pine nut oil is expected to have features of both phytosterol and PLA. In this study, lipase from Candida rugosa (CRL) was immobilized and then used to optimize conditions for synthesis of phytosteryl ester containing PLA. Lewatit VP OC 1600, a macroporous hydrophobic resin, was selected as the best carrier, and the optimum condition for the immobilization of CRL was established. With immobilized CRL prepared, synthesis of phytosteryl ester with fatty acid from pine nut oil was carried out. Parameters investigated were temperature, molar ratio (phytosterol to fatty acid), enzyme loading, and vacuum. Optimum conditions for synthesis of phytosteryl ester were a temperature of 60 °C, molar ratio of 1:4, enzyme loading of 10% (based on the total weight of the substrate), and pressure of 80 kPa. The maximum conversion of phytosteryl ester was ca. 93 mol % at the optimum condition.

The purpose of this work was to measure the changes in -aminobutyric acid (GABA) and polyphenolic content of two different rice varieties (Geunnun and Ilpum), as well as the antiproliferative activities of both germinated brown rice varieties in cancer cells. The contents of GABA in Geunnun and Ilpum, especially in the bran of Ilpum increased significantly after germination. The content of polyphenol in Geunnun also increased after germination, but the contents of flavonoid in both varieties decreased after germination. A significant increase in the antiproliferative activity of both varieties on human lung and gastric cancer cell line was observed after germination.

Rice is an important agricultural commodity and a major staple food in Asian diets. The aims of this study were to investigate the antioxidant activities and phytochemical contents of methanolic extracts from specialty rice cultivars and to determine if there is any correlation between antioxidant activity and phytochemical content. Our results indicate that methanolic extracts from different rice cultivars contain different levels of phenolics, anthocyanin, carotenoids, γ-oryzanol, and vitamin E. Black rice cultivars such as ‘Heugkwang’, ‘Heugseol’, and ‘Heugjinju’ contained higher phytochemical contents compared to other cultivars. In contrast, the cultivars ‘Segyejinmi’, ‘Cheonseok’, ‘Hanareum’, and ‘Dasan 1’ contained significantly higher levels of γ-tocotrienol compared with other cultivars. The black rice cultivars also showed higher antioxidant activities. Phenolic content was positively correlated with DPPH and ABTS radical scavenging activities and reducing power. The results could have a direct impact on rice consumption by enhancing consumer awareness of health benefits of the rice.

This study was conducted to determine antioxidant compounds and antioxidant activities of rice bran at temperatures of 10℃, 25℃, and 60℃ 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 ㎎ gallic acid eq./100 g in 10℃, 25℃ and 60℃, 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℃. 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.