The effects of polishing on proximate compositions,physico-chemical characteristics,mineral compositions and antioxidant properties of the rice flours obtained from three different pigmented rice varieties(Chak-hao An...The effects of polishing on proximate compositions,physico-chemical characteristics,mineral compositions and antioxidant properties of the rice flours obtained from three different pigmented rice varieties(Chak-hao Angangba,Chak-hao Amubi and Chak-hao Poireiton) were investigated.The rice varieties were significantly(P < 0.05) different in the contents of the test characteristics.Lipids,ash,minerals,phytochemicals(phenolic acids and flavonoids) and 2,2-diphenyl-1-picrylhydrazyl(DPPH) activity of rice flours were decreased after polishing(9% degree of milling),while amylose content and lightness were increased.X-ray diffraction pattern of rice flours exhibited A-type crystalline pattern with reflections at 15.1o,17.1o,18.2o and 23.0o.Pasting properties and transition temperatures were decreased after polishing treatment.Polishing resulted in changes in the crystallinity,enthalpy and morphology of rice flours.展开更多
Red rice(Oryza punctata) is a type of unpolished rice which has higher nutritional value compared to white rice or even polished rice. Owing to higher nutritive content and metabolites, dieticians strongly advise red ...Red rice(Oryza punctata) is a type of unpolished rice which has higher nutritional value compared to white rice or even polished rice. Owing to higher nutritive content and metabolites, dieticians strongly advise red rice for peoples with metabolic disorders including diabetics. However, the mechanism of action and contents of secondary metabolites in Indian red rice variety not reported scientifically. Therefore, the present study aimed to evaluate its mechanism of action through inhibitory effect of α-amylase and α-glucosidase. Initially, the whole grain of red rice was macerated with methanol at room temperature for 2 weeks. Then, the dried and powdered, samples at different concentrationfi(2.5, 10, 40, and 80 μg/m L) were employed to nd out in vitro inhibitory effects on α-amylase and α-glucosidase. In addition, an enzyme kinetics of effective extract was calculated by Line-weaver Burk(LWB) plot analysis. Moreover,the valuable metabolites in the efficient methanolic extract were quantified using high performance liquid chromatography(HPLC). The results demonstrated that red rice methanolic extract(RRMEt) possess strong inhibitory activity onα-amylase and α-glucosidase compared with acarbose(P < 0.01). The IC50 values of RRMEt was found to be 29.7 ±7.43 μg/m L for α-amylase and 20.4 ± 0.25 μg/m L for α-glucosidase. LWB indicated that RRMEt is an uncompetitive inhibitor. Further, HPLC analysis revealed protocatechuic acid, catechin, and chlorogenic acids were more abundant in RRMEt among the fourteen metabolites. We conclude, the efficiency of enzyme inhibition through the influence of phenolic compounds in RRMEt.展开更多
Objective:To study the inhibitory effect of rice bran extracts of Thai black Kam Muang and red Hawm Dawk Mali Deang on oxidative stress factors including superoxide(O2·-),nitric oxide(NO·),and inducible nitr...Objective:To study the inhibitory effect of rice bran extracts of Thai black Kam Muang and red Hawm Dawk Mali Deang on oxidative stress factors including superoxide(O2·-),nitric oxide(NO·),and inducible nitric oxide synthase(iNOS).Methods:Bran extracts(40%ethanol)of Kam Muang and Hawm Dawk Mali Deang were obtained and evaluated for in vitro 2-2′-azino-di-(3-ethylbenzthiazoline sulfonate)(ABTS)and NO·scavenging activity.Their inhibitory effects on cellular O2·-and NO·were measured in phorbol 12-myristate 13-acetate-stimulated neutrophil-like HL-60 cells and lipopolysaccharidestimulated RAW264.7 macrophages,respectively,and their viability was monitored using the MTT assay.The effect on iNOS expression was also assessed by the Western blotting assay.Total contents of phenolics,flavonoids,and subtypes were also determined.Results:Hawm Dawk Mali Deang exhibited about 3.5-fold greater cellular O2·-inhibitory activity than Kam Muang[EC50 values of(23.57±4.54)and(81.98±1.45)μg/mL,respectively]in phorbol 12-myristate 13-acetate-stimulated HL-60 cells.Hawm Dawk Mali Deang exhibited about 2-fold higher in vitro ABTS·+and NO·scavenging activity than Kam Muang,but it exerted cellular NO·inhibitory activity of only about 26%(undetermined EC50 value)in lipopolysaccharide-stimulated RAW264.7 cells.Conversely,Kam Muang exerted potent cellular NO·inhibitory activity[EC50 value:(281.13±59.18)μg/mL]and dose-dependently decreased iNOS levels.No cytotoxicity of both extracts was detected in both cell types.As for corresponding contents,Hawm Dawk Mali Deang contained higher contents of phenolics and flavonoids than Kam Muang.Moreover,Kam Muang and Hawm Dawk Mali Deang had a high content of total anthocyanins[(14.73±0.52)mg C3GE/g of extract]and total proanthocyanidins[(115.13±1.47)mg CE/g of extract],respectively.Conclusions:Based on these data,bran extracts of Thai black Kam Muang and red rice Hawm Dawk Mali Deang can help lower oxidative stress and inflammation attributed partly to O2·-and NO·.展开更多
The potential of SCAR marker for discrimination of a Thai jasmine rice (Oryza sativa L. cv. KDML 105) mutant, BKOS6, obtained from ion-beam-induced mutation, was evaluated. The improved rice variety, BKOS6, exhibited ...The potential of SCAR marker for discrimination of a Thai jasmine rice (Oryza sativa L. cv. KDML 105) mutant, BKOS6, obtained from ion-beam-induced mutation, was evaluated. The improved rice variety, BKOS6, exhibited many remarkable characteristics which fitted the multiple cropping system characteristics of progressive agriculture including photoperiod insensitivity, early flowering, short in stature, and purple pigment accumulation in pericarp. The BKOS6 rice grain extract has already been proved that it exhibited higher antioxidant properties than the KDML 105 and other tested rice grain extracts. In this study, the BKOS6 specific SCAR marker was developed by HAT-RAPD analysis of rice genomic DNA. The marker was successfully used to identify BKOS6 variety and its hybrid varieties containing purple pigment accumulation in plant tissues. Moreover, it was found that this marker could be used to detect other purple pigmented rice varieties that genetically related to Thai jasmine rice. Recently, a wide variety of anthocyanin-based foods are believed to provide significant potential health benefits, and become more attractive. KDML 105 is also a Thai premier fragrant rice variety which is one of the main varieties of country’s rice export. Thus this molecular marker could be useful for commercial and breeding purposes of BKOS6 mutant and other developed varieties from KDML 105 which contain anthocyanin accumulation.展开更多
基金Department of Food Science and Technology,Pondicherry University,India for providing facilities and support in carrying out the research
文摘The effects of polishing on proximate compositions,physico-chemical characteristics,mineral compositions and antioxidant properties of the rice flours obtained from three different pigmented rice varieties(Chak-hao Angangba,Chak-hao Amubi and Chak-hao Poireiton) were investigated.The rice varieties were significantly(P < 0.05) different in the contents of the test characteristics.Lipids,ash,minerals,phytochemicals(phenolic acids and flavonoids) and 2,2-diphenyl-1-picrylhydrazyl(DPPH) activity of rice flours were decreased after polishing(9% degree of milling),while amylose content and lightness were increased.X-ray diffraction pattern of rice flours exhibited A-type crystalline pattern with reflections at 15.1o,17.1o,18.2o and 23.0o.Pasting properties and transition temperatures were decreased after polishing treatment.Polishing resulted in changes in the crystallinity,enthalpy and morphology of rice flours.
基金Department of Science and Technology,Government of India,for providing INSPIRE Fellowshipauthorities of Annamalai University for providing necessary support
文摘Red rice(Oryza punctata) is a type of unpolished rice which has higher nutritional value compared to white rice or even polished rice. Owing to higher nutritive content and metabolites, dieticians strongly advise red rice for peoples with metabolic disorders including diabetics. However, the mechanism of action and contents of secondary metabolites in Indian red rice variety not reported scientifically. Therefore, the present study aimed to evaluate its mechanism of action through inhibitory effect of α-amylase and α-glucosidase. Initially, the whole grain of red rice was macerated with methanol at room temperature for 2 weeks. Then, the dried and powdered, samples at different concentrationfi(2.5, 10, 40, and 80 μg/m L) were employed to nd out in vitro inhibitory effects on α-amylase and α-glucosidase. In addition, an enzyme kinetics of effective extract was calculated by Line-weaver Burk(LWB) plot analysis. Moreover,the valuable metabolites in the efficient methanolic extract were quantified using high performance liquid chromatography(HPLC). The results demonstrated that red rice methanolic extract(RRMEt) possess strong inhibitory activity onα-amylase and α-glucosidase compared with acarbose(P < 0.01). The IC50 values of RRMEt was found to be 29.7 ±7.43 μg/m L for α-amylase and 20.4 ± 0.25 μg/m L for α-glucosidase. LWB indicated that RRMEt is an uncompetitive inhibitor. Further, HPLC analysis revealed protocatechuic acid, catechin, and chlorogenic acids were more abundant in RRMEt among the fourteen metabolites. We conclude, the efficiency of enzyme inhibition through the influence of phenolic compounds in RRMEt.
基金supported by the National Research Council of Thailand and the Faculty of Medicine,Thammasat University
文摘Objective:To study the inhibitory effect of rice bran extracts of Thai black Kam Muang and red Hawm Dawk Mali Deang on oxidative stress factors including superoxide(O2·-),nitric oxide(NO·),and inducible nitric oxide synthase(iNOS).Methods:Bran extracts(40%ethanol)of Kam Muang and Hawm Dawk Mali Deang were obtained and evaluated for in vitro 2-2′-azino-di-(3-ethylbenzthiazoline sulfonate)(ABTS)and NO·scavenging activity.Their inhibitory effects on cellular O2·-and NO·were measured in phorbol 12-myristate 13-acetate-stimulated neutrophil-like HL-60 cells and lipopolysaccharidestimulated RAW264.7 macrophages,respectively,and their viability was monitored using the MTT assay.The effect on iNOS expression was also assessed by the Western blotting assay.Total contents of phenolics,flavonoids,and subtypes were also determined.Results:Hawm Dawk Mali Deang exhibited about 3.5-fold greater cellular O2·-inhibitory activity than Kam Muang[EC50 values of(23.57±4.54)and(81.98±1.45)μg/mL,respectively]in phorbol 12-myristate 13-acetate-stimulated HL-60 cells.Hawm Dawk Mali Deang exhibited about 2-fold higher in vitro ABTS·+and NO·scavenging activity than Kam Muang,but it exerted cellular NO·inhibitory activity of only about 26%(undetermined EC50 value)in lipopolysaccharide-stimulated RAW264.7 cells.Conversely,Kam Muang exerted potent cellular NO·inhibitory activity[EC50 value:(281.13±59.18)μg/mL]and dose-dependently decreased iNOS levels.No cytotoxicity of both extracts was detected in both cell types.As for corresponding contents,Hawm Dawk Mali Deang contained higher contents of phenolics and flavonoids than Kam Muang.Moreover,Kam Muang and Hawm Dawk Mali Deang had a high content of total anthocyanins[(14.73±0.52)mg C3GE/g of extract]and total proanthocyanidins[(115.13±1.47)mg CE/g of extract],respectively.Conclusions:Based on these data,bran extracts of Thai black Kam Muang and red rice Hawm Dawk Mali Deang can help lower oxidative stress and inflammation attributed partly to O2·-and NO·.
文摘The potential of SCAR marker for discrimination of a Thai jasmine rice (Oryza sativa L. cv. KDML 105) mutant, BKOS6, obtained from ion-beam-induced mutation, was evaluated. The improved rice variety, BKOS6, exhibited many remarkable characteristics which fitted the multiple cropping system characteristics of progressive agriculture including photoperiod insensitivity, early flowering, short in stature, and purple pigment accumulation in pericarp. The BKOS6 rice grain extract has already been proved that it exhibited higher antioxidant properties than the KDML 105 and other tested rice grain extracts. In this study, the BKOS6 specific SCAR marker was developed by HAT-RAPD analysis of rice genomic DNA. The marker was successfully used to identify BKOS6 variety and its hybrid varieties containing purple pigment accumulation in plant tissues. Moreover, it was found that this marker could be used to detect other purple pigmented rice varieties that genetically related to Thai jasmine rice. Recently, a wide variety of anthocyanin-based foods are believed to provide significant potential health benefits, and become more attractive. KDML 105 is also a Thai premier fragrant rice variety which is one of the main varieties of country’s rice export. Thus this molecular marker could be useful for commercial and breeding purposes of BKOS6 mutant and other developed varieties from KDML 105 which contain anthocyanin accumulation.
