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1.
Ying Yong Sheng Tai Xue Bao ; 30(8): 2717-2724, 2019 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-31418197

RESUMO

Rice straw is a potential material for bioenergy production. Elevated atmospheric carbon dioxide (CO2) concentration changed the quantity and quality of rice straw, thus changing its bioenergy production potential. In this experiment, we collected rice straw from China Free Air CO2 Enrichment Platform (FACE). Three rice varieties, Wuyunjing 27, Y Liangyou 900 and Nipponbare N16, were selected from the FACE platform (the CO2 concentration in the experimental group was controlled at 570 µmol ·mol-1, which was 200 µmol ·mol-1 higher than the control group), the chemical composition of which was analyzed. The results showed that elevated CO2 concentration significantly increased C content, C/N, and the content of non-structural carbohydrates in straw. Elevated CO2 concentration significantly increased total sugar release by 8.8%, 6.7% and 9.9% in Wuyunjing 27, Y liangyou 900 and N16, respectively. Elevated CO2 concentration significantly enhanced the biomass of N16 straw, but had no effect on the straw biomass of the other two rice varieties. The total sugar yield of N16 increased most significantly with elevated CO2 concentration, reaching 19.2%. Our results indicated that elevated CO2 concentration could improve the quality and quantity of rice straw, thereby increasing the utilization potential of biofuel.


Assuntos
Dióxido de Carbono/análise , Oryza/química , Atmosfera/química , Biomassa , China
2.
J Agric Food Chem ; 67(35): 9877-9884, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31398030

RESUMO

Heavy metal contaminants and nutrient deficiencies in soil negatively affect crop growth and human health. The plant cadmium resistance (PCR) protein transports heavy metals. The abundance of PCR is correlated with that of cell number regulator (CNR) protein, and the two proteins have similar conserved domains. Hence, CNR might also participate in heavy metal transport. We isolated and analyzed TaCNR5 from wheat (Triticum aestivum). The expression level of TaCNR5 in the shoots of wheat increased under cadmium (Cd), zinc (Zn), or manganese (Mn) treatments. Transgenic plants expressing TaCNR5 showed enhanced tolerance to Zn and Mn. Overexpression of TaCNR5 in Arabidopsis increased Cd, Zn, and Mn translocation from roots to shoots. The concentrations of Zn and Mn in rice grains were increased in transgenic plants expressing TaCNR5. These roles of TaCNR5 in the translocation and distribution of heavy metals mean that it has potential as a genetic biofortification tool to fortify cereal grains with micronutrients.


Assuntos
Manganês/metabolismo , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/genética , Triticum/genética , Zinco/metabolismo , Arabidopsis/química , Arabidopsis/genética , Arabidopsis/metabolismo , Biofortificação , Transporte Biológico , Cádmio/análise , Cádmio/metabolismo , Manganês/análise , Oryza/química , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/química , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Triticum/química , Triticum/metabolismo , Zinco/análise
3.
World J Microbiol Biotechnol ; 35(8): 129, 2019 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-31376017

RESUMO

Metal whole-cell biosensors (WCBs) have been reported as very useful tools to detect and quantify the presence of bioavailable fractions of certain metals in water and soil samples. In the current work, two bacterial WCBs able to report Cr(VI) presence and plants growing on Cr(VI)-enriched soil/medium were used to assess the potential transfer of this metal to organisms of higher trophic levels, and the risk of transfer to the food chain. To do it, the functionality of the WCBs within tissues of inoculated plants in contact with Cr(VI)-contaminated soil and water was studied in vitro and in a controlled greenhouse environment. One WCB was the previously described Ochrobactrum tritici pCHRGFP2 and the second, Nitrospirillum amazonense pCHRGFP2, is a newly engineered naturally-occurring endophytic microorganism. Three rice varieties (IAC 4440, BRS 6 CHUÍ, IRGA 425) and one maize variety (1060) were tested as hosts and subjected to Cr(VI) treatments (25 µM), with different results obtained. Inoculation of each WCB into plants exposed to Cr(VI) showed GFP expression within plant tissues. WCBs penetrated the root tissues and later colonized the shoots and leaves. In general, a higher fluorescence signal was detected in roots, together with a higher Cr content and denser WCB colonization. Best fluorescence intensities per plant biomass of shoots were obtained for plant host IRGA 425. Therefore, by analyzing colonized tissues, both WCBs allowed the detection of Cr(VI) contamination in soils and its transfer to plants commonly used in crops for human diet.


Assuntos
Técnicas Biossensoriais/métodos , Cromo/análise , Ochrobactrum/crescimento & desenvolvimento , Oryza/química , Rhodospirillaceae/crescimento & desenvolvimento , Zea mays/química , Disponibilidade Biológica , Engenharia Metabólica , Microscopia de Fluorescência , Ochrobactrum/genética , Ochrobactrum/metabolismo , Oryza/crescimento & desenvolvimento , Oryza/microbiologia , Rhodospirillaceae/genética , Rhodospirillaceae/metabolismo , Poluentes do Solo/análise , Poluentes Químicos da Água/análise , Zea mays/crescimento & desenvolvimento , Zea mays/microbiologia
4.
Plant Foods Hum Nutr ; 74(3): 405-413, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31273642

RESUMO

The aim of this work was to evaluate the ability of broken rice, an underutilized industrial by-product, as a potential functional and health promoting ingredient. With this purpose, the ability to inhibit the angiotensin converting enzyme and renin of a rice protein hydrolyzate (RPH) obtained from a high-protein variety of broken rice (var. Nutriar FCAyF) was analyzed (IC50 = 0.87 and 2.7 mg/mL, respectively). RPH was separated by gel permeation chromatography and in a second purification step by RP-HPLC. The sequence of antihypertensive peptides presented in two RP-HPLC fractions was analyzed. Peptides capable of interacting with the active sites of both enzymes were identified. In this study, we demonstrate that the hydrolysis treatment improves functional and biological properties of rice proteins. Protein preparations obtained from a by-product of rice industry, such as broken rice, are a promising ingredient with potentially good biological properties.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/farmacologia , Anti-Hipertensivos/isolamento & purificação , Oryza/química , Peptídeos/isolamento & purificação , Renina/antagonistas & inibidores , Anti-Hipertensivos/farmacologia , Cromatografia Líquida de Alta Pressão , Promoção da Saúde , Hidrólise , Simulação de Acoplamento Molecular , Peptídeos/farmacologia , Peptidil Dipeptidase A/metabolismo , Proteínas de Plantas/antagonistas & inibidores , Proteínas de Plantas/metabolismo , Renina/metabolismo
5.
Sci Total Environ ; 690: 321-328, 2019 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-31299567

RESUMO

Cadmium (Cd)-contaminated paddy soil has become a global agricultural safety issue. The application of foliage dressing with mineral elements to alleviate Cd toxicity in rice might offer a cost-effective and practical strategy for safe food production. In this study, a pot experiment was conducted to optimize foliar composition and dosage. Field experiments in two consecutive rice seasons were performed to investigate the effectiveness and mechanisms of foliage dressing. Foliar spray of S, P, and a mixture of both were effective to reduce the Cd concentration in rice grain. The maximum decrease by leaf-grain translocation was achieved at 84%, and the maximum decrease of bio-concentration was 69% in the stem. The reduction of Cd concentration in rice decreased the direct damage to the photosynthetic system, and then increased the rice growth. Foliage dressing relieved the oxidative stress of Cd to rice by decreasing the MDA content, and increasing antioxidant enzyme activities. Foliar spray with S likely reduced Cd accumulation in rice by minimizing the production of reactive oxygen species, improving the activities of enzymatic and non-enzymatic antioxidant defense systems, and manipulating glutathione synthesis. The detoxification of foliar spray with P was originated from the decrease of Cd translocation and maintaining photosynthetic machinery. These results indicated that foliage dressing with S and P has great potential for the remediation of vast agricultural fields.


Assuntos
Cádmio/química , Oryza/química , Agricultura/métodos , Recuperação e Remediação Ambiental/métodos , Fósforo/química , Solo , Poluentes do Solo , Enxofre/química
6.
Zhongguo Zhong Yao Za Zhi ; 44(9): 1814-1821, 2019 May.
Artigo em Chinês | MEDLINE | ID: mdl-31342707

RESUMO

Commercially available japonica rice and indica rice with different trade names were collected,and then based on the method of rice stir-frying,their many indexes were evaluated,for example the physical and chemical properties such as appearance color,grain type,broken kernel ratio,length-width ratio,1 000-grain weight,specific heat capacity,moisture content,amylose content,and protein content. The discriminant function analysis was used to determine the effective factors affecting the quality of rice as excipients. The results showed that two types of rice could be distinguished by rice color parameter a*,grain parameter circularity,1 000-grain weight and amylose content. These four effective factors can be used as the quality evaluation indexes for fried rice as excipients.Protein is one of the main components of rice,and its content affects the quality of rice. There is a significant difference in the protein content between japonica rice and indica rice. Therefore,protein content should be used as one of the evaluation indexes for rice quality. After comprehensive consideration,it is suggested that the red-green value a*shall not be less than 0. 50; the circularity not less than 53. 0,the 1 000-grain weight not less than 16. 0 g,the amylose content not less than 12. 0% and the protein content not less than4. 0% in the japonica rice; the red-green value a*shall not be lower than-1. 0,the circularity not less than 41. 0,the 1 000-grain weight not less than 13. 0 g,the amylose content not less than 9. 0% and the protein content not less than 3. 5% in the indica rice. In this study,the quality evaluation standards for rice as excipients( japonica rice,indica rice) were supplemented and improved,laying foundation for the development of quality standards for rice as excipients with the rice stir-frying method.


Assuntos
Culinária , Excipientes , Qualidade dos Alimentos , Oryza/química , Amilose , Temperatura Alta
7.
J Agric Food Chem ; 67(28): 7986-7994, 2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-31282158

RESUMO

Compositional analyses were performed on samples of rice grain, straw, and derived bran obtained from golden rice event GR2E and near-isogenic control PSBRc82 rice grown at four locations in the Philippines during 2015 and 2016. Grain samples were analyzed for key nutritional components, including proximates, fiber, polysaccharides, fatty acids, amino acids, minerals, vitamins, and antinutrients. Samples of straw and bran were analyzed for proximates and minerals. The only biologically meaningful difference between GR2E and control rice was in levels of ß-carotene and other provitamin A carotenoids in the grain. Except for ß-carotene and related carotenoids, the compositional parameters of GR2E rice were within the range of natural variability of those components in conventional rice varieties with a history of safe consumption. Mean provitamin A concentrations in milled rice of GR2E can contribute up to 89-113% and 57-99% of the estimated average requirement for vitamin A for preschool children in Bangladesh and the Philippines, respectively.


Assuntos
Oryza/genética , Plantas Geneticamente Modificadas/química , Sementes/química , Aminoácidos/análise , Aminoácidos/metabolismo , Bangladesh , Ácidos Graxos/análise , Ácidos Graxos/metabolismo , Alimentos Geneticamente Modificados , Engenharia Genética , Valor Nutritivo , Oryza/química , Oryza/metabolismo , Filipinas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Provitaminas/análise , Provitaminas/metabolismo , Sementes/genética , Sementes/metabolismo , Vitamina A/análise , Vitamina A/metabolismo , beta Caroteno/análise , beta Caroteno/metabolismo
8.
J Agric Food Chem ; 67(32): 9032-9038, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31334646

RESUMO

It is estimated that approximately 200 million people are exposed to arsenic levels above the World Health Organization provisional guideline value, and various agencies have indicated the need to reduce this exposure. In view of the difficulty of removing arsenic from water and food, one alternative is to reduce its bioavailability (the amount that reaches the systemic circulation after ingestion). In this study, dietary components [glutathione, tannic acid, and Fe(III)] were used to achieve this goal. As(III) or As(V) (1 mg/kg body weight) was administered daily to BALB/c mice, along with the dietary components, for 15 days. The results confirm the efficacy of Fe(III) and glutathione as reducers of arsenic bioavailability and tissue accumulation. Also, these treatments did not result in reductions of Ca, K, P, and Fe contents in the liver. These data suggest that use of these two compounds could be part of valid strategies for reducing inorganic arsenic exposure in chronically exposed populations.


Assuntos
Arsenicais/metabolismo , Compostos Férricos/química , Glutationa/química , Animais , Arsenicais/química , Disponibilidade Biológica , Exposição Dietética/análise , Exposição Dietética/prevenção & controle , Compostos Férricos/metabolismo , Contaminação de Alimentos/análise , Glutationa/metabolismo , Fígado/metabolismo , Pulmão/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Oryza/química , Oryza/metabolismo
9.
Food Chem ; 298: 124949, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260990

RESUMO

Starch digestibility and polyphenol content were investigated in six (white, red and purple) Thai rice varieties. Total phenolic content (TPC), total anthocyanin content (TAC), amylose content, gelatinization parameters and in vitro digestibility were determined. Purple and red rice varieties were found to have the highest levels of TPC, TAC and amylose content. TAC was not detected in white rice, while purple rice had the highest values. Gelatinization parameters were determined using differential scanning calorimetry. Red rice (Sung Yod) showed the highest gelatinization enthalpy. Non-pigmented rice (Hom Mali) in both purified starch and flour showed the highest starch digestibility, with a total starch digestibility of 76.85% and a digestion rate of 0.25 min-1. In contrast pigmented rice varieties showed lower starch digestibility. These results suggest that pigmented rice varieties are a source of phenolics and anthocyanin and also a possible good source of low digestible starch to develop as functional food products.


Assuntos
Antocianinas/análise , Oryza , Amido/química , Amilose/análise , Varredura Diferencial de Calorimetria , Digestão , Farinha/análise , Humanos , Oryza/química , Oryza/metabolismo , Fenóis/análise , Pigmentação , Amido/farmacocinética , Tailândia
10.
BMC Vet Res ; 15(1): 233, 2019 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-31286932

RESUMO

BACKGROUND: The increasing costs of feed has subsequently increased the costs of production of livestock, thereby decreasing the profit margin of this sector. The utilization of agro-industrial by-products has to some extent substitute some of the corn grains and soyabean meal, commonly used in animal feeds. In Malaysia, palm kernel cake (PKC) is a by-product of the oil palm industry and is frequently used to supply both crude protein (14-16% CP) and energy (11 MJ/kg) in ruminants. The energy and protein content are adequate for maintenance in the majority of ruminants. However, highly available energy supplementation is known to improve growth performance and protein deposition. This study was carried out to determine the effect on the quality of meat and fatty acid composition of the semitendinosus (ST), supraspinatus (SS), and longissimus lumborum (LL) muscles of Dorper lambs by including corn as an energy source in a basal diet of PKC urea-treated rice straw. RESULTS: The results show that the LL muscle-drip loss was greater in animals supplemented with 5% corn compared to the other groups. Higher pH values of SS and LL muscles were observed in animals supplemented with 5 and 10% corn. Furthermore, the L* value of ST muscle was increased in lambs fed on 5% corn while, reduced in those fed on 0% corn, but the a* and b* values were not significantly different in the treatment groups. The fatty acid composition of the SS muscles showed that lambs fed on 10% corn had higher levels of sum PUFA n-3 compared to those fed on 0% corn. The concentration of C18:1trans11 and CLA c12 t10 in ST muscle from the lambs fed on supplemented diets were higher than those of the controls. CONCLUSION: This study has concluded the supplementation of corn as a source of energy into a PKC urea-treated rice straw-based diet increased the PUFA concentrations of muscles as compared to control groups.


Assuntos
Fenômenos Fisiológicos da Nutrição Animal , Dieta/veterinária , Ácidos Graxos/análise , Carne/normas , Músculo Esquelético/química , Oryza/química , Zea mays/metabolismo , Ração Animal/normas , Animais , Malásia , Músculo Esquelético/metabolismo , Ovinos , Ureia/química
11.
J Agric Food Chem ; 67(29): 8205-8211, 2019 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-31250639

RESUMO

The quantitation of three Strecker aldehydes-2-methypropanal (2-MP), 2-methylbutanal (2-MB), and 3-methylbutanal (3-MB)-from rice bran protein hydrolysate (RBPH) prepared under various conditions were investigated. The preparation conditions included hydrolysis time (0, 0.25, 2, 4, or 8 h), pH adjustment (pH 4.0, 7.0, or 10.0), and sugar addition (sucrose, glucose, or fructose). These conditions provide a significant potential for aroma generation from the Strecker degradation and Maillard reaction. The Strecker aldehyde quantitation was performed using gas chromatography (GC) with cryo-focusing technique. These combined techniques encourage the precise 2-MB and 3-MB quantitation. The highest concentrations of three Strecker aldehydes were found in RBPH that was prepared by alcalase hydrolysis at 4 h with fructose addition (RBPH-F) and adjusted to pH 7.0 before spray drying. Thirty-nine aroma-active compounds of RBPH-F were discovered using solid-phase microextraction coupled with GC-olfactometry.


Assuntos
Aldeídos/química , Oryza/química , Proteínas de Plantas/química , Aldeídos/isolamento & purificação , Cromatografia Gasosa , Hidrólise , Reação de Maillard , Odorantes/análise , Hidrolisados de Proteína/química , Microextração em Fase Sólida
12.
Food Chem ; 295: 327-333, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31174765

RESUMO

Dual-pulse laser-induced breakdown spectroscopy (DPLIBS) and chemometric methods were used to predict chromium content in rice leaves, along with the purpose for increasing the detection sensitivity and accuracy. The influence of important parameters in DPLIBS were investigated and optimized. Then, partial least square (PLS) was used to establish chromium content prediction models, and the value of regression coefficient based on PLS was applied to determine feature variables. In addition, multivariate and univariate analysis were used to verify the modeling performance of selected feature variables. The results indicated that support vector machine model based on feature variables achieved the best performance, with correlation coefficient of 0.9946, root mean square error of 4.85 mg/kg and residual predictive deviation of 9.70 in prediction set. The proposed method provides a high-accuracy and fast approach for chromium content prediction in rice leaves, which could potentially be used for toxic and nutrient elements detection in food.


Assuntos
Cromo/análise , Oryza/química , Folhas de Planta/química , Análise Espectral/métodos , Poluentes Ambientais/análise , Lasers , Análise dos Mínimos Quadrados , Luz , Sensibilidade e Especificidade , Análise Espectral/estatística & dados numéricos , Máquina de Vetores de Suporte
13.
Food Chem ; 297: 124912, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253263

RESUMO

An anti-idiotypic nanobody-phage display-mediated immuno-polymerase chain reaction (PD-IPCR) method was developed for simultaneous quantitative detection of total aflatoxins and zearalenone in cereals. Two phages, displaying the variable domain of the heavy chain anti-idiotypic nanobody that binds aflatoxin- or zearalenone-specific monoclonal antibody (1C11 or 2D3), were used as competitors for corresponding analytes. Specific DNA sequences encoding anti-idiotypic nanobodies were used to design the primers for PCR amplification. The results indicated that detection limits for total aflatoxins and zearalenone in a sample were 0.03 and 0.09 ng mL-1, respectively. Recoveries of spiked aflatoxins and zearalenone were 80-118% and 76.7-111%, respectively. Validation results were in good agreement with the gold-standard high-performance liquid chromatography method. This report is the first to describe PD-IPCR for simultaneous quantitative detection of total aflatoxins and zearalenone in cereals.


Assuntos
Aflatoxinas/análise , Anticorpos Anti-Idiotípicos/imunologia , Imunoensaio/métodos , Zearalenona/análise , Aflatoxinas/imunologia , Anticorpos Anti-Idiotípicos/genética , Cromatografia Líquida de Alta Pressão , Limite de Detecção , Oryza/química , Oryza/metabolismo , Biblioteca de Peptídeos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Anticorpos de Domínio Único/genética , Anticorpos de Domínio Único/imunologia , Zea mays/química , Zea mays/metabolismo , Zearalenona/imunologia
14.
J Sci Food Agric ; 99(12): 5577-5585, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31150111

RESUMO

BACKGROUND: One of the most important species used to ferment Chinese turbid rice wine (CTRW) at an industrial-scale level is Rhizopus oryzae, although the flavor of CTRW fermented by pure R. oryzae is inferior to that of traditional CTRW. RESULTS: Mucor indicus was used as a cooperative species to improve the flavor of CTRW presented by R. oryzae. The flavor compounds in different fermentation stages were determined by headspace solid-phase microextraction-gas chromatography-mass spectrometry and high-performance liquid chromatography. It was noted that the M. indicus and R. oryzae co-culture changed the profiles of flavor compounds in CTRW, including esters, higher alcohols, amino acids and organic acids, and also significantly enhanced the concentration of sweet amino acids, fruity and floral esters, and higher alcohols. Sensory evaluation demonstrated that the CTRW fermented by M. indicus and R. oryzae had a more intense aroma, harmonious taste, continuation and full body mouth-feel because of more abundant flavor compounds. CONCLUSION: Mucor indicus is a promising species for co-culture with R. oryzae to improve the flavor of CTRW. © 2019 Society of Chemical Industry.


Assuntos
Aromatizantes/química , Mucor/metabolismo , Oryza/microbiologia , Rhizopus/metabolismo , Vinho/análise , China , Técnicas de Cocultura , Fermentação , Aromatizantes/isolamento & purificação , Cromatografia Gasosa-Espectrometria de Massas , Mucor/crescimento & desenvolvimento , Odorantes/análise , Oryza/química , Rhizopus/crescimento & desenvolvimento , Microextração em Fase Sólida , Paladar , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/isolamento & purificação , Vinho/microbiologia
15.
J Sci Food Agric ; 99(12): 5558-5564, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31150114

RESUMO

BACKGROUND: Rice adulteration in the food industry that infringes on the interests of consumers is considered very serious. To realize the rapid and precise quantitation of adulterated rice, a visible near infrared (VNIR) hyperspectral imaging system (380-1000 nm) was developed in the present study. A Savitsky-Golay first derivative (SG1) transform was utilized to eliminate the constant spectral baseline offset. Then, the adulterated levels of rice samples were quantified by partial least squares regression (PLSR). RESULTS: A SG1-PLSR model based on full-wavelength was attained with a coefficient of determination of prediction set (RP ) of 0.9909, root-mean-square error of prediction set (RMSEP ) of 0.0447 g kg-1 and residual predictive deviation (RPDP ) of 11.28. Furthermore, fifteen important wavelengths were selected based on the weighted regression coefficients (BW ) and a simplified model (PLSR-15) was established with RP of 0.9769, RMSEP of 0.0708 g kg-1 and RPDP of 3.49. Finally, two visualization maps produced by applying the optimal models (SG1-PLSR and PLSR-15) were used to visualize the adulterated levels of rice. CONCLUSION: These results demonstrate that VNIR hyperspectral imaging system is an effective tool for rapidly quantifying and visualizing the adulterated levels of rice. © 2019 Society of Chemical Industry.


Assuntos
Oryza/química , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Contaminação de Alimentos/análise , Análise dos Mínimos Quadrados
16.
Food Chem ; 297: 124960, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253301

RESUMO

Rice is the most consumed food worldwide, therefore its designation of origin (PDO) is very useful. Laser-induced breakdown spectroscopy (LIBS) is an interesting analytical technique for PDO certification, since it provides fast multielemental analysis requiring minimal sample treatment. In this work LIBS spectral data from rice analysis were evaluated for PDO certification of Argentine brown rice. Samples from two PDOs were analyzed by LIBS coupled to spark discharge. The selection of spectral data was accomplished by extreme gradient boosting (XGBoost), an algorithm currently used in machine learning, but rarely applied in chemical issues. Emission lines of C, Ca, Fe, Mg and Na were selected, and the best performance of classification were obtained using k-nearest neighbor (k-NN) algorithm. The developed method provided 84% of accuracy, 100% of sensitivity and 78% of specificity in classification of test samples. Furthermore, it is simple, clean and can be easily applied for rice certification.


Assuntos
Análise de Alimentos/métodos , Oryza/química , Análise Espectral/métodos , Algoritmos , Argentina , Análise de Alimentos/estatística & dados numéricos , Lasers , Metais/análise , Metais/química , Análise Espectral/estatística & dados numéricos
17.
Food Chem ; 297: 124956, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253306

RESUMO

The objective of this study was to evaluate the effect of the extrusion moisture and temperature on the physical characteristics of breakfast cereals. The chemical composition, microbiological risk and acceptance of the selected breakfast cereal with the best physical quality were assessed to determine the technological viability of the use of these by-products by the food industry. The response surface method and a rotatable central composite design were used, and a desirability test was performed based on adjusted regression models. The breakfast cereal produced under these conditions had protein, lipid and dietary fiber contents of 7.55, 0.97 and 6.12 g 100 g-1, respectively. In regards to the sensory analysis, the evaluated breakfast cereal received average acceptance scores ranging from "neither like or dislike" to "like moderately". The use of rice, passion fruit and milk by-products was shown to be an alternative for the production of extruded breakfast cereal.


Assuntos
Grão Comestível/química , Alimentos Especializados , Desjejum , Dieta Livre de Glúten , Fibras na Dieta/análise , Indústria de Processamento de Alimentos/métodos , Lipídeos , Oryza/química , Passiflora/química , Proteínas de Vegetais Comestíveis/análise , Pós , Soro do Leite/química
18.
Food Chem ; 297: 124978, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253262

RESUMO

Rice glutelin (RG) and phosphorylated rice glutelin (PPRG) were treated with heating for different time (15, 30, and 45 min), the effects of phosphorylation modification on the structure, interactions and rheological properties of rice glutelin during heat treatment were investigated. The results showed that the turbidity of PPRG samples were higher than those of RG samples after heating. Particle size distribution showed that the protein aggregates with particle size of 1000-1500 nm were formed after heating for 45 min. Changes in protein structure indicated that the protein unfolded after heating for a short time, and aggregated when heating time extended to 45 min. In addition, the microstructure of PPRG sample became tight when heated for 45 min. Rheological analysis showed that phosphorylation modification and heat treatment improved RG viscoelasticity. These results suggest that phosphorylation modification improves thermal aggregation of RG, which will facilitate the application of RG in food industry.


Assuntos
Glutens/análise , Estrutura Molecular , Oryza/química , Agregados Proteicos , Reologia , Indústria Alimentícia , Calefação , Temperatura Alta , Tamanho da Partícula , Fosforilação , Viscosidade
19.
Food Chem ; 297: 124984, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253275

RESUMO

The present research was carried out to analyze the effect of chemical composition, granule morphology and crystalline structure of pigmented rice starches on their functional characteristics. The starches of these rice cultivars were observed to possess novel characteristic as compared to hybrids or non-pigmented cultivars in terms of physicochemical, pasting and thermal characteristics. The diameter of the analyzed starch particles depicted a considerable range varying from 5.139 µm to 8.453 µm as their median particle size visualized at ×50. The color values of the analyzed starch samples indicated a high degree of whiteness and purity. The compact nature of starch granules in Kaw quder and Kaw kareed rice cultivars accounted for their higher transition temperatures as compared to other cultivars. Crystalline pattern by X-Ray diffractometer showed an A-type pattern for analyzing starches. The starch granules showed the irregular polyhedral morphology with spherical granules having a polyhedral angular shaped morphology packed tightly with a relatively smooth surface.


Assuntos
Oryza/química , Amido/química , Amilose/química , Amilose/ultraestrutura , Microscopia Eletrônica de Varredura , Óleos/química , Oryza/ultraestrutura , Tamanho da Partícula , Amido/ultraestrutura , Temperatura de Transição , Viscosidade , Água/química , Difração de Raios X
20.
Food Chem ; 293: 1-7, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31151588

RESUMO

The bioaccessibility and speciation of arsenic (As) in rice grains have been investigated by the physiologically based extraction test (PBET) method. A total of 42 rice samples were collected from Hunan Province, a typical mine-impacted province in China. The bioaccessibility in the gastrointestinal tract was 71.7 ±â€¯13.5% for the collected rice grains. Arsenite [As(III)] was the predominant As species in the simulated gastric and gastrointestinal solutions, followed by dimethylarsinic acid (DMA), arsenate [As(V)] and monomethylarsonic acid (MMA). The bioaccessible As(V) was irrelevant to As(V) in the rice grains, suggesting that interconversion between As(V) and other species was occurred in the simulated gastrointestinal tract. Monte-Carlo simulation was introduced to assess the health risk from exposure to inorganic As. The average values for target hazard quotient (THQ) and bioaccessible THQ were 2.704 and 1.637, respectively. The inclusion of bioaccessibility reduced the probability of non-carcinogenic health risk from 97.32% to 76.86%.


Assuntos
Arsenicais/metabolismo , Oryza/química , Arsênico/metabolismo , Arsenicais/análise , Arsenitos/metabolismo , Ácido Cacodílico/metabolismo , Humanos , Espectrometria de Massas , Método de Monte Carlo , Oryza/metabolismo , Medição de Risco
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