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1.
Int J Med Mushrooms ; 16(6): 585-91, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25404223

RESUMO

To find a cost-effective alternative substrate, the medicinal mushroom Ganoderma lucidum was grown on sawdusts of sheesham, mango, and poplar. Optimum spawn level was determined by spawning in substrates at various levels (1, 2, 3, and 4%). To determine the effect of supplementation, substrates were supplemented with wheat bran, rice bran and corn flour at different concentrations (10, 20, and 30%). Duration of growth cycle, mushroom yield, and biological efficiency data were recorded. Among substrates, mango sawdust was superior, with 1.5-fold higher yields than poplar sawdust, which was the least suitable. However with respect to fructification, mango sawdust produced the first primordia earlier (21±1 days) compared with the other investigated substrates. 3% spawn level was found to be optimal irrespective of the substrate. Yield and biological efficiency (BE) were maximally enhanced by supplementation with wheat bran, whereas rice bran was the least suitable supplement among those tested. Growth cycle shortened and mushroom yield increased to a maximum at the 20% level of supplements. Mango sawdust in combination with 20% wheat bran, if spawned at the 3% level, resulted in a high yield (BE = 58.57%).


Assuntos
Análise Custo-Benefício , Meios de Cultura/economia , Ganoderma/crescimento & desenvolvimento , Microbiologia Industrial/economia , Madeira/economia , Fibras na Dieta/economia , Ganoderma/metabolismo , Índia , Microbiologia Industrial/métodos , Oryza/economia , Zea mays/economia
3.
Environ Entomol ; 43(3): 828-39, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24780114

RESUMO

Experimentally manipulated water and insect stresses were applied to field-grown corn with different Bacillus thuringiensis (Bt) transgenes and no Bt transgenes, and different nontransgenic hybrid backgrounds (2011 and 2012, Corpus Christi, TX). Differences in leaf injury, ear injury, and yield were detected among experimental factors and their interactions. Under high and low water stress, injury from noctuid larvae (Lepidoptera: Noctuidae) on leaves during vegetative growth (primarily from fall armyworm, Spodoptera frugiperda J.E. Smith) and on developing ears (primarily from corn earworm, Helicoverpa zea [Boddie]) was lowest on more recent releases of Bt hybrids (newer Bt hybrids) expressing Cry1A.105+Cry2Ab2 and Cry 3Bb1, compared with earlier Bt hybrids (older Bt hybrids) expressing Cry1Ab and Cry3Bb1 and non-Bt hybrids. High water stress led to increased leaf injury under substantial fall armyworm feeding pressure in 2011 (as high as 8.7 on a 1-9 scale of increasing injury). In contrast, ear injury by corn earworm (as high as 20 cm(2) of surface area of injury) was greater in low water stress conditions. Six hybrid backgrounds did not influence leaf injury, while ear injury differences across hybrid backgrounds were detected for non-Bt and older Bt hybrid versions. While newer Bt hybrids expressing Cry1A.105+Cry2Ab2 and Cry 3Bb1 had consistent low leaf injury and high yield and low but less consistent ear injury across six hybrid backgrounds, water stress was a key factor that influenced yield. Bt transgenes played a more variable and lesser role when interacting with water stress to affect yield. These results exemplify the interplay of water and insect stress with plant injury and yield, their interactions with Bt transgenes, and the importance of these interactions in considering strategies for Bt transgene use where water stress is common.


Assuntos
Proteínas de Bactérias/farmacologia , Endotoxinas/farmacologia , Proteínas Hemolisinas/farmacologia , Mariposas/fisiologia , Plantas Geneticamente Modificadas/fisiologia , Zea mays/fisiologia , Animais , Bacillus thuringiensis/genética , Toxinas de Bacillus thuringiensis , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Dessecação , Endotoxinas/genética , Endotoxinas/metabolismo , Comportamento Alimentar , Cadeia Alimentar , Proteínas Hemolisinas/genética , Proteínas Hemolisinas/metabolismo , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Larva/fisiologia , Mariposas/efeitos dos fármacos , Mariposas/crescimento & desenvolvimento , Controle Biológico de Vetores , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/fisiologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Texas , Transgenes , Zea mays/economia , Zea mays/genética , Zea mays/crescimento & desenvolvimento
4.
Int J Occup Environ Health ; 20(1): 61-70, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24804340

RESUMO

Atrazine, an herbicide used on most of the US corn (maize) crop, is the subject of ongoing controversy, with increasing documentation of its potentially harmful health and environmental impacts. Supporters of atrazine often claim that it is of great value to farmers; most recently, Syngenta, the producer of atrazine, sponsored an "Atrazine Benefits Team" (ABT) of researchers who released a set of five papers in 2011, reporting huge economic benefits from atrazine use in US agriculture. A critical review of the ABT papers shows that they have underestimated the growing problem of atrazine-resistant weeds, offered only a partial review of the effectiveness of alternative herbicides, and ignored the promising option of nonchemical weed management techniques. In addition, the most complete economic analysis in the ABT papers implies that withdrawal of atrazine would lead to a decrease in corn yields of 4.4% and an increase in corn prices of 8.0%. The result would be an increase in corn growers' revenues, equal to US$1.7 billion annually under ABT assumptions. Price impacts on consumers would be minimal: at current levels of ethanol production and use, gasoline prices would rise by no more than US$0.03 per gallon; beef prices would rise by an estimated US$0.01 for a 4-ounce hamburger and US$0.05 for an 8-ounce steak. Thus withdrawal of atrazine would boost farm revenues, while only changing consumer prices by pennies.


Assuntos
Atrazina/análise , Herbicidas/análise , Controle de Plantas Daninhas/métodos , Zea mays/efeitos dos fármacos , Atrazina/economia , Política Ambiental , Regulamentação Governamental , Herbicidas/economia , Estados Unidos , Controle de Plantas Daninhas/economia , Controle de Plantas Daninhas/instrumentação , Zea mays/economia
5.
Ann N Y Acad Sci ; 1312: 105-12, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24650320

RESUMO

Maize (Zea mays), also called corn, is believed to have originated in central Mexico 7000 years ago from a wild grass, and Native Americans transformed maize into a better source of food. Maize contains approximately 72% starch, 10% protein, and 4% fat, supplying an energy density of 365 Kcal/100 g and is grown throughout the world, with the United States, China, and Brazil being the top three maize-producing countries in the world, producing approximately 563 of the 717 million metric tons/year. Maize can be processed into a variety of food and industrial products, including starch, sweeteners, oil, beverages, glue, industrial alcohol, and fuel ethanol. In the last 10 years, the use of maize for fuel production significantly increased, accounting for approximately 40% of the maize production in the United States. As the ethanol industry absorbs a larger share of the maize crop, higher prices for maize will intensify demand competition and could affect maize prices for animal and human consumption. Low production costs, along with the high consumption of maize flour and cornmeal, especially where micronutrient deficiencies are common public health problems, make this food staple an ideal food vehicle for fortification.


Assuntos
Ingestão de Alimentos , Manipulação de Alimentos/métodos , Alimentos Fortificados/estatística & dados numéricos , Micronutrientes , Zea mays , Manipulação de Alimentos/economia , Alimentos Fortificados/economia , Humanos , Micronutrientes/administração & dosagem , Micronutrientes/economia , Organização Mundial da Saúde , Zea mays/economia
7.
J Food Sci ; 79(2): C138-46, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24547694

RESUMO

Anthocyanins are important dietary components with diverse positive functions in human health. This study investigates effects of accelerated solvent extraction (ASE) and microwave-assisted extraction (MAE) on anthocyanin composition and extraction efficiency from blue wheat, purple corn, and black rice in comparison with the commonly used solvent extraction (CSE). Factorial experimental design was employed to study effects of ASE and MAE variables, and anthocyanin extracts were analyzed by spectrophotometry, high-performance liquid chromatography-diode array detector (DAD), and liquid chromatography-mass spectrometry chromatography. The extraction efficiency of ASE and MAE was comparable with CSE at the optimal conditions. The greatest extraction by ASE was achieved at 50 °C, 2500 psi, 10 min using 5 cycles, and 100% flush. For MAE, a combination of 70 °C, 300 W, and 10 min in MAE was the most effective in extracting anthocyanins from blue wheat and purple corn compared with 50 °C, 1200 W, and 20 min for black rice. The anthocyanin composition of grain extracts was influenced by the extraction method. The ASE extraction method seems to be more appropriate in extracting anthocyanins from the colored grains as being comparable with the CSE method based on changes in anthocyanin composition. The method caused lower structural changes in anthocaynins compared with the MAE method. Changes in blue wheat anthocyanins were lower in comparison with purple corn or black rice perhaps due to the absence of acylated anthocyanin compounds in blue wheat. The results show significant differences in anthocyanins among the 3 extraction methods, which indicate a need to standardize a method for valid comparisons among studies and for quality assurance purposes.


Assuntos
Antocianinas/isolamento & purificação , Grão Comestível/química , Inspeção de Alimentos/métodos , Pigmentos Biológicos/biossíntese , Extratos Vegetais/isolamento & purificação , Acilação , Antocianinas/análise , Antocianinas/metabolismo , Canadá , Grão Comestível/economia , Grão Comestível/metabolismo , Grão Comestível/efeitos da radiação , Qualidade dos Alimentos , Temperatura Alta , Humanos , Extração Líquido-Líquido , Micro-Ondas , Valor Nutritivo , Oryza/química , Oryza/economia , Oryza/metabolismo , Oryza/efeitos da radiação , Extratos Vegetais/química , Extratos Vegetais/efeitos da radiação , Pressão , Reprodutibilidade dos Testes , Sementes/química , Sementes/metabolismo , Sementes/efeitos da radiação , Fatores de Tempo , Triticum/química , Triticum/metabolismo , Triticum/efeitos da radiação , Zea mays/química , Zea mays/economia , Zea mays/metabolismo , Zea mays/efeitos da radiação
8.
Ann N Y Acad Sci ; 1312: 40-53, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24329609

RESUMO

Mass fortification of maize flour and corn meal with a single or multiple micronutrients is a public health intervention that aims to improve vitamin and mineral intake, micronutrient nutritional status, health, and development of the general population. Micronutrient malnutrition is unevenly distributed among population groups and is importantly determined by social factors, such as living conditions, socioeconomic position, gender, cultural norms, health systems, and the socioeconomic and political context in which people access food. Efforts trying to make fortified foods accessible to the population groups that most need them require acknowledgment of the role of these determinants. Using a perspective of social determinants of health, this article presents a conceptual framework to approach equity in access to fortified maize flour and corn meal, and provides nonexhaustive examples that illustrate the different levels included in the framework. Key monitoring areas and issues to consider in order to expand and guarantee a more equitable access to maize flour and corn meal are described.


Assuntos
Farinha/economia , Abastecimento de Alimentos/economia , Alimentos Fortificados/economia , Micronutrientes/economia , Zea mays/economia , Abastecimento de Alimentos/métodos , Humanos , Micronutrientes/administração & dosagem , Estado Nutricional , Vigilância da População/métodos , Saúde Pública/economia , Saúde Pública/métodos
9.
Pest Manag Sci ; 70(11): 1711-9, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24338991

RESUMO

BACKGROUND: Recent evidence indicates that some populations of European corn borer (ECB), Ostrinia nubilalis (Hübner), have declined to historic lows owing to widespread adoption of Bt corn hybrids. To understand current ECB populations in Pennsylvania field corn, the authors assessed larval damage in Bt and non-Bt corn hybrids at 29 sites over 3 years. The influence of Bt adoption rates, land cover types and moth activity on levels of ECB damage was also considered. RESULTS: Bt hybrids reduced ECB damage when compared with non-Bt, but these differences inconsistently translated to higher yields and, because of higher seed costs, rarely improved profits. No relationships were detected between land use or Bt adoption and ECB damage rates, but positive relationships were found between plant damage and captures of Z-race ECB moths in pheromone traps in the PestWatch network. CONCLUSIONS: ECB damage levels were generally low and appear to be declining across Pennsylvania. In many locations, farmers may gain greater profits by planting competitive non-Bt hybrids; however, Bt hybrids remain valuable control options, particularly in the parts of Pennsylvania where ECB populations persist. Moth captures from PestWatch appear to provide insight into where Bt hybrids are most valuable.


Assuntos
Mariposas/fisiologia , Controle Biológico de Vetores/métodos , Zea mays/genética , Animais , Bacillus thuringiensis/genética , Comportamento Alimentar , Larva/fisiologia , Mariposas/genética , Pennsylvania , Controle Biológico de Vetores/economia , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Zea mays/economia , Zea mays/crescimento & desenvolvimento
10.
Ann N Y Acad Sci ; 1312: 26-39, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24102661

RESUMO

The economic feasibility of maize flour and maize meal fortification in Kenya, Uganda, and Zambia is assessed using information about the maize milling industry, households' purchases and consumption levels of maize flour, and the incremental cost and estimated price impacts of fortification. Premix costs comprise the overwhelming share of incremental fortification costs and vary by 50% in Kenya and by more than 100% across the three countries. The estimated incremental cost of maize flour fortification per metric ton varies from $3.19 in Zambia to $4.41 in Uganda. Assuming all incremental costs are passed onto the consumer, fortification in Zambia would result in at most a 0.9% increase in the price of maize flour, and would increase annual outlays of the average maize flour-consuming household by 0.2%. The increases for Kenyans and Ugandans would be even less. Although the coverage of maize flour fortification is not likely to be as high as some advocates have predicted, fortification is economically feasible, and would reduce deficiencies of multiple micronutrients, which are significant public health problems in each of these countries.


Assuntos
Farinha/economia , Alimentos Fortificados/economia , Produtos Domésticos/economia , Marketing/economia , Zea mays/economia , África/etnologia , Custos e Análise de Custo/economia , Estudos de Viabilidade , Humanos , Quênia/etnologia , Marketing/métodos , Uganda/etnologia , Zâmbia/etnologia
11.
Pest Manag Sci ; 70(11): 1684-96, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24318916

RESUMO

BACKGROUND: Atrazine and other triazine herbicides are widely used in US maize and sorghum production, yet the most recent market-level assessment of the economic benefits of atrazine is for market conditions prevalent in the early 1990s, before commercialization of transgenic crops. Grain markets have changed substantially since that time; for example, the size of the US maize market increased by 170% from 1990-1992 to 2007-2009. This paper reports a current assessment of the economic benefits of atrazine. RESULTS: Yield increases and cost changes implied by triazine herbicides are projected to reduce maize prices by 7-8% and sorghum prices by 19-20%. Projected consumer benefits from lower prices range from $US 3.6 to 4.4 × 10(9) annually, with the net projected economic benefit for triazine herbicides to the US economy ranging from $US 2.9 to 3.4 × 10(9) annually because lower prices imply reduced producer income. Productivity gains from triazine herbicides maintain an estimated 270 000-390 000 ha of land in non-crop uses that generate environmental benefits not accounted for in this analysis. CONCLUSION: Even in the current era, with transgenic varieties dominating crop production, atrazine and the other triazine herbicides continue to be a key part of maize and sorghum production and generate substantial economic benefits.


Assuntos
Atrazina/economia , Produtos Agrícolas/economia , Controle de Pragas/economia , Agricultura/métodos , Produtos Agrícolas/crescimento & desenvolvimento , Herbicidas/economia , Sorghum/crescimento & desenvolvimento , Estados Unidos , Zea mays/economia , Zea mays/crescimento & desenvolvimento
12.
Genet Mol Res ; 12(2): 2109-19, 2013 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-23913390

RESUMO

The objective of this study was to determine the optimal number of repetitions to be used in competition trials of popcorn traits related to production and quality, including grain yield and expansion capacity. The experiments were conducted in 3 environments representative of the north and northwest regions of the State of Rio de Janeiro with 10 Brazilian genotypes of popcorn, consisting by 4 commercial hybrids (IAC 112, IAC 125, Zélia, and Jade), 4 improved varieties (BRS Ângela, UFVM-2 Barão de Viçosa, Beija-flor, and Viçosa) and 2 experimental populations (UNB2U-C3 and UNB2U-C4). The experimental design utilized was a randomized complete block design with 7 repetitions. The Bootstrap method was employed to obtain samples of all of the possible combinations within the 7 blocks. Subsequently, the confidence intervals of the parameters of interest were calculated for all simulated data sets. The optimal number of repetition for all of the traits was considered when all of the estimates of the parameters in question were encountered within the confidence interval. The estimates of the number of repetitions varied according to the parameter estimated, variable evaluated, and environment cultivated, ranging from 2 to 7. It is believed that only the expansion capacity traits in the Colégio Agrícola environment (for residual variance and coefficient of variation), and number of ears per plot, in the Itaocara environment (for coefficient of variation) needed 7 repetitions to fall within the confidence interval. Thus, for the 3 studies conducted, we can conclude that 6 repetitions are optimal for obtaining high experimental precision.


Assuntos
Algoritmos , Cruzamento , Cruzamentos Genéticos , Zea mays/economia , Brasil , Cruzamento/economia , Intervalos de Confiança , Genótipo , Hibridização Genética , Característica Quantitativa Herdável , Sementes/genética , Seleção Genética , Zea mays/genética
13.
J Agric Food Chem ; 61(35): 8254-9, 2013 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-23668783

RESUMO

Plant breeding for crop genetic improvement involves the cycle of creating genetic diversity and exploiting that diversity to derive an improved cultivar with outstanding performance for specific traits of interest. Genetic modification through transformation essentially expands the genepool to facilitate access to genes otherwise not available through crossing. Transgenic events are defined by the DNA sequence that has been incorporated into the target genome and the specific point(s) of insertion. In the development of a new transgenic trait, typically many events are generated and evaluated with the aim of identifying one exhibiting consistent trait expression at or above specified thresholds, stable inheritance, and the absence of any negative effects. With transgenic traits for maize, once commercial candidates have been identified, these events are introgressed into elite lines, often through the use of molecular markers that can accelerate the breeding process and aid in producing a quality conversion. Converted elite lines are yield-tested to ensure performance equivalency with their unconverted counterparts. Finally, before commercial sale of seed, quality control monitoring is conducted to ensure event identity and purity and the absence of any unintended events. This monitoring complements other quality control measures to confirm seed viability and line/hybrid purity and uniformity in seed treatments, all in an effort to ensure customer satisfaction and to comply with governmental regulations. Thus, genetically modified (GM) cultivars are subject to significant testing and auditing prior to seed sale and distribution to farmers, more testing and auditing than with non-GM cultivars.


Assuntos
Tecnologia de Alimentos/métodos , Plantas Geneticamente Modificadas , Zea mays/genética , Agricultura/economia , Agricultura/métodos , Cruzamento , Comércio , DNA de Plantas/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Controle de Qualidade , Característica Quantitativa Herdável , Sementes , Zea mays/economia
14.
Bioresour Technol ; 140: 426-30, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23706349

RESUMO

A techno-economic sensitivity analysis was performed using a National Renewable Energy Laboratory (NREL) 2011 biochemical conversion design model varying feedstock compositions. A total of 496 feedstock near infrared (NIR) compositions from 47 locations in eight US Corn Belt states were used as the inputs to calculate minimum ethanol selling price (MESP), ethanol yield (gallons per dry ton biomass feedstock), ethanol annual production, as well as total installed project cost for each composition. From this study, the calculated MESP is $2.20 ± 0.21 (average ± 3 SD) per gallon ethanol.


Assuntos
Etanol/economia , Resíduos/economia , Zea mays/química , Zea mays/economia , Biotecnologia/economia , Comércio/economia , Energia Renovável , Espectroscopia de Luz Próxima ao Infravermelho
15.
Plant Mol Biol ; 83(1-2): 5-19, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23430566

RESUMO

Genetically engineered (GE) crops can be used as part of a combined strategy to address food insecurity, which is defined as a lack of sustainable access to safe and nutritious food. In this article, we discuss the causes and consequences of food insecurity in the developing world, and the indirect economic impact on industrialized countries. We dissect the healthcare costs and lost productivity caused by food insecurity, and evaluate the relative merits of different intervention programs including supplementation, fortification and the deployment of GE crops with higher yields and enhanced nutritional properties. We provide clear evidence for the numerous potential benefits of GE crops, particularly for small-scale and subsistence farmers. GE crops with enhanced yields and nutritional properties constitute a vital component of any comprehensive strategy to tackle poverty, hunger and malnutrition in developing countries and thus reduce the global negative economic effects of food insecurity.


Assuntos
Abastecimento de Alimentos/economia , Alimentos Geneticamente Modificados/economia , Engenharia Genética/métodos , Produtos Agrícolas/economia , Produtos Agrícolas/genética , Deficiências Nutricionais/economia , Atenção à Saúde/economia , Atenção à Saúde/organização & administração , Países em Desenvolvimento , Suplementos Nutricionais/economia , Oryza/economia , Oryza/genética , Pobreza/prevenção & controle , Zea mays/economia , Zea mays/genética
17.
Artigo em Inglês | MEDLINE | ID: mdl-24779874

RESUMO

A total of 214 samples, consisting of brown rice, barley, mixed grains, corn, wheat and wheat flour were analysed for T-2 and HT-2 toxins using high-performance liquid chromatography with fluorescence detection. Recovery and repeatability were 79.9%-107.5% and 4.9%-14.5% for T-2, and 74.0%-106.1% and 5.0%-17.9% for HT-2, respectively. T-2 toxin was detected in 11 (5.1%) of all samples. The highest incidence was found in corn (21.7%) followed by mixed grains and brown rice. Mean of all samples was 1.5-4.1 µg kg⁻¹, the maximum level being 41.5 µg kg⁻¹ in corn. HT-2 toxin was detected in 126 (58.9%) of all samples, and the mean values were 26.4-59.2 µg kg⁻¹. The estimated daily intakes for the sum of T-2 and HT-2 toxins were 2.56, 3.22, 2.53, 0.03, 0.01 and 2.45 ng (kg bw)⁻¹ day⁻¹ in brown rice, barley, mixed grains, corn, wheat and wheat flour, respectively.


Assuntos
Grão Comestível/química , Farinha/análise , Contaminação de Alimentos , Inspeção de Alimentos/métodos , Imunossupressores/análise , Sementes/química , Toxina T-2/análise , Cromatografia Líquida de Alta Pressão , Dieta/efeitos adversos , Dieta/etnologia , Grão Comestível/economia , Farinha/economia , Hordeum/química , Hordeum/economia , Humanos , Imunossupressores/toxicidade , Limite de Detecção , Oryza/química , Oryza/economia , Venenos/análise , Venenos/toxicidade , Reprodutibilidade dos Testes , República da Coreia , Medição de Risco , Espectrometria de Fluorescência , Espectrometria de Massas por Ionização por Electrospray , Toxina T-2/análogos & derivados , Toxina T-2/toxicidade , Triticum/química , Triticum/economia , Zea mays/química , Zea mays/economia
18.
Food Nutr Bull ; 33(2): 99-110, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22908691

RESUMO

BACKGROUND: New maize varieties have been biofortified with provitamin A, mainly a-carotene, which renders the grain yellow or orange. Unfortunately, many African consumers prefer white maize. The maize consumption patterns in Africa are, however, not known. OBJECTIVE: To determine which maize products African consumers prefer to purchase and which maize preparations they prefer to eat. METHODS: A survey of 600 consumers was conducted in Nairobi, Kenya, at three types of maize outlets: posho mills (small hammer mills), kiosks, and supermarkets. RESULTS: Clients of posho mills had lower incomes and less education than those of kiosks and supermarkets. The preferred maize product of the posho-mill clients was artisanal maize meal; the preferred product of the others was industrial maize meal. Maize is the preferred staple for lunch and dinner, eaten as a stiff porridge (ugali), followed by boiled maize and beans (githeri), regardless of socioeconomic background. For breakfast, only half the consumers prefer maize, mostly as a soft porridge (uji). This proportion is higher in low-income groups. Consumers show a strong preference for white maize over yellow, mostly for its organoleptic characteristics, and show less interest in biofortified maize. CONCLUSIONS: Maize is the major food staple in Nairobi, mostly eaten in a few distinct preparations. For biofortified yellow maize to be accepted, a strong public awareness campaign to inform consumers is needed, based on a sensory evaluation and the mass media, in particular on radio in the local language.


Assuntos
Comportamento do Consumidor , Dieta , Preferências Alimentares , Alimentos Geneticamente Modificados , Pigmentos Biológicos/metabolismo , Sementes/metabolismo , Zea mays/metabolismo , Adulto , Comportamento do Consumidor/economia , Informação de Saúde ao Consumidor/economia , Países em Desenvolvimento , Dieta/economia , Dieta/etnologia , Escolaridade , Feminino , Manipulação de Alimentos/economia , Preferências Alimentares/etnologia , Alimentos Geneticamente Modificados/efeitos adversos , Alimentos Geneticamente Modificados/economia , Conhecimentos, Atitudes e Prática em Saúde/etnologia , Humanos , Quênia , Masculino , Inquéritos Nutricionais , Fatores Socioeconômicos , Saúde da População Urbana/economia , Saúde da População Urbana/etnologia , Zea mays/economia
19.
Artigo em Inglês | MEDLINE | ID: mdl-22827234

RESUMO

Climate change is anticipated to affect European agriculture, including the risk of emerging or re-emerging feed and food hazards. Indirectly, climate change may influence such hazards (e.g. the occurrence of mycotoxins) due to geographic shifts in the distribution of major cereal cropping systems and the consequences this may have for crop rotations. This paper analyses the impact of climate on cropping shares of maize, oat and wheat on a 50-km square grid across Europe (45-65°N) and provides model-based estimates of the changes in cropping shares in response to changes in temperature and precipitation as projected for the time period around 2040 by two regional climate models (RCM) with a moderate and a strong climate change signal, respectively. The projected cropping shares are based on the output from the two RCMs and on algorithms derived for the relation between meteorological data and observed cropping shares of maize, oat and wheat. The observed cropping shares show a south-to-north gradient, where maize had its maximum at 45-55°N, oat had its maximum at 55-65°N, and wheat was more evenly distributed along the latitudes in Europe. Under the projected climate changes, there was a general increase in maize cropping shares, whereas for oat no areas showed distinct increases. For wheat, the projected changes indicated a tendency towards higher cropping shares in the northern parts and lower cropping shares in the southern parts of the study area. The present modelling approach represents a simplification of factors determining the distribution of cereal crops, and also some uncertainties in the data basis were apparent. A promising way of future model improvement could be through a systematic analysis and inclusion of other variables, such as key soil properties and socio-economic conditions, influencing the comparative advantages of specific crops.


Assuntos
Agricultura/economia , Avena/crescimento & desenvolvimento , Mudança Climática , Produtos Agrícolas/crescimento & desenvolvimento , Inocuidade dos Alimentos , Triticum/crescimento & desenvolvimento , Zea mays/crescimento & desenvolvimento , Agricultura/tendências , Animais , Avena/química , Avena/economia , Avena/microbiologia , Mudança Climática/economia , Produtos Agrícolas/química , Produtos Agrícolas/economia , Produtos Agrícolas/microbiologia , Europa (Continente) , Previsões/métodos , Fungos/crescimento & desenvolvimento , Fungos/metabolismo , Humanos , Modelos Biológicos , Modelos Econômicos , Micotoxinas/análise , Micotoxinas/biossíntese , Poluentes do Solo/efeitos adversos , Poluentes do Solo/análise , Análise Espaço-Temporal , Triticum/química , Triticum/economia , Triticum/microbiologia , Incerteza , Tempo (Meteorologia) , Zea mays/química , Zea mays/economia , Zea mays/microbiologia
20.
Environ Sci Technol ; 46(11): 6379-84, 2012 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-22533454

RESUMO

The approximately 100 million tonne per year increase in the use of corn to produce ethanol in the U.S. over the past 10 years, and projections of greater future use, have raised concerns that reduced exports of corn (and other agricultural products) and higher commodity prices would lead to land-use changes and, consequently, negative environmental impacts in other countries. The concerns have been driven by agricultural and trade models, which project that large-scale corn ethanol production leads to substantial decreases in food exports, increases in food prices, and greater deforestation globally. Over the past decade, the increased use of corn for ethanol has been largely matched by the increased corn harvest attributable mainly to increased yields. U.S. exports of corn, wheat, soybeans, pork, chicken, and beef either increased or remained unchanged. Exports of distillers' dry grains (DDG, a coproduct of ethanol production and a valuable animal feed) increased by more than an order of magnitude to 9 million tonnes in 2010. Increased biofuel production may lead to intensification (higher yields) and extensification (more land) of agricultural activities. Intensification and extensification have opposite impacts on land use change. We highlight the lack of information concerning the magnitude of intensification effects and the associated large uncertainties in assessments of the indirect land use change associated with corn ethanol.


Assuntos
Agricultura , Biocombustíveis/economia , Comércio/economia , Etanol/metabolismo , Alimentos/economia , Zea mays/economia , Zea mays/crescimento & desenvolvimento , Estados Unidos
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