237 research outputs found
Deciding Between Grain and Forage Harvest for Late Maturing Corn
Irregular development and lateness of Iowa crops this year are cause for reflection as producers conduct late season evaluation of crops in individual fields, and plan when and how to harvest them for the greatest economic advantage. Late season evaluation involves reviewing normal crop growth and development, assessing the condition of the crops in individual fields relative to normal, and thinking through several autumn season scenarios such as: How will this field develop between now and the normal frost time? What are the concerns or alternatives if a frost comes one or two weeks earlier than normal
Alternatives for Drought-damaged Corn—Grain Crop or Forage
As people reflect on the reasons for the irregular development and poor grain production in Iowa this year, the next important questions relate to evaluation of crops in individual fields and planning when and how to harvest them to the greatest economic advantage. This evaluation involves reviewing normal crop growth and development, assessing the condition of the crops in individual fields relative to normal, and to think through several harvest scenarios such as: Will this field have a harvestable grain crop? Are there concerns about the crops? What use or management alternatives do I have
"Quantum Interference with Slits" Revisited
Marcella [arXiv:quant-ph/0703126] has presented a straightforward technique
employing the Dirac formalism to calculate single- and double-slit interference
patterns. He claims that no reference is made to classical optics or scattering
theory and that his method therefore provides a purely quantum mechanical
description of these experiments. He also presents his calculation as if no
approximations are employed. We show that he implicitly makes the same
approximations found in classical treatments of interference and that no new
physics has been introduced. At the same time, some of the quantum mechanical
arguments Marcella gives are, at best, misleading.Comment: 11 pages, 3 figure
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The use of asparaginase to reduce acrylamide levels in cooked food
Strategies proposed for reducing the formation of the suspected carcinogen acrylamide in cooked foods often rely on a reduction in the extent of the Maillard reaction, in which acrylamide is formed from the reaction between asparagine and reducing sugars. However, the Maillard reaction also provides desirable sensory attributes of cooked foods. Mitigation procedures that modify the Maillard reaction may negatively affect flavour and colour. The use of asparaginase to convert asparagine to aspartic acid may provide a means to reduce acrylamide formation, while maintaining sensory quality. This review collates research on the use of enzymes, asparaginase in particular, to mitigate acrylamide formation. Asparaginase is a powerful tool for the food industry and it is likely that its use will increase. However, the potential adverse effects of asparaginase treatment on sensory properties of cooked foods and the need to achieve sufficient enzyme–substrate contact remain areas for future research
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Effect of sugar reduction on flavour release and sensory perception in an orange juice soft drink model
To examine the effect of sugar reduction on the sensory perception of sweetened beverages, an orange juice soft drink model flavoured with seven characteristic compounds (hexanal, decanal, linalool, ethyl butanoate, α-pinene, β-myrcene and (Z)-3-hexen-1-ol) was developed. Five samples were prepared with relevant sugar contents (5.2, 8.2, 9.7, 11.2 and 14.2 °Brix). Using retronasal quantitative descriptive analysis (QDA), nine attributes were found to differ significantly (p < 0.05) with sugar content. When the samples were evaluated orthonasally, only the attribute “overripe orange” significantly decreased (p < 0.05) with reduction of sugar content. Headspace solid-phase microextraction with gas chromatography–mass spectrometry showed that as sugar concentration decreased, the headspace concentration of six of the volatile compounds decreased, whilst ethyl butanoate remained constant. Principal component analysis revealed that the total release of the flavour compounds was highly correlated with the perceived intensity of the orthonasal attribute “overripe orange”
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Evaluation of 2-acetyl-1-pyrroline in foods, with an emphasis on rice flavour
The popcorn-like aroma compound 2-acetyl-1-pyrroline (2-AP) is a key contributor to the desirable aroma of fragrant rice and is also important in the aroma of other foods, such as pandan leaf, popcorn and Mediterranean sausage. It can be formed enzymatically in the rice grain as it grows and is also formed, as part of the Maillard reaction, when rice is heated. This review examines the formation of 2-AP in rice and other foods, particularly its formation during cooking, focusing on the importance of the Maillard reaction between reducing sugar breakdown products and 1-pyrroline derived from the amino acids proline and ornithine. The synthesis of 2-AP is discussed alongside the attempts that have been made to stabilise this relatively unstable compound. The analysis of 2-AP by instrumental techniques, particularly gas chromatography-mass spectrometry and gas chromatography-olfactometry, alongside the use of sensory studies, is also discussed
Disaster Recovery—Managing immature crops for grain or silage
Tips on managing crops that may not mature before the first killing freeze of fall.https://lib.dr.iastate.edu/extension_ag_pubs/1203/thumbnail.jp
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Stress, nutrients and genotype: understanding and managing asparagine accumulation in wheat grain
Plant stress and poor crop management strategies compromise the foundations of food security: crop yield, nutritional quality and food safety. Accumulation of high concentrations of the amino acid asparagine in its free (soluble, non-protein) form is an example of an undesirable outcome of stress for the nutritional quality and food safety of wheat because of its role as a precursor to acrylamide, a carcinogenic processing contaminant. In this review, we cover what is known about the mechanisms and functions of free asparagine accumulation in the grain during normal development and particularly during stress in wheat. Comparisons with other plant species, yeast, and mammals are drawn in order to gain deeper insight into the conserved biology underlying asparagine accumulation. Crop management strategies and practices are discussed in the context of managing asparagine accumulation, which must be balanced against other desirable goals, such as sustainability, protein content and yield
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A review of the factors that influence pesticide residues in pollen and nectar: future research requirements for optimising the estimation of pollinator exposure
In recent years, the impact of Plant Protection Products (PPPs) on insect pollinator decline has stimulated significant amounts of research, as well as political and public interest. PPP residues have been found in various bee-related matrices, resulting in governmental bodies worldwide releasing guidance documents on methods for the assessment of the overall risk of PPPs to different bee species. An essential part of these risk assessments are PPP residues found in pollen and nectar, as they represent a key route of exposure. However, PPP residue values in these matrices exhibit large variations and are not available for many PPPs and crop species combinations, which results in inaccurate estimations and uncertainties in risk evaluation. Additionally, residue studies on pollen and nectar are expensive and practically challenging. An extrapolation between different cropping scenarios and PPPs is not yet justified, as the behaviour of PPPs in pollen and nectar is poorly understood. Therefore, this review aims to contribute to a better knowledge and understanding of the fate of PPP residues in pollen and nectar and to outline knowledge gaps and future research needs. The literature suggests that four primary factors, the crop type, the application method, the physicochemical properties of a compound and the environmental conditions have the greatest influence on PPP residues in pollen and nectar. However, these factors consist of many sub-factors and initial effects may be disguised by different sampling methodologies, impeding their exact characterisation. Moreover, knowledge about these factors is ambiguous and restricted to a few compounds and plant species. We propose that future research should concentrate on identifying relationships and common features amongst various PPP applications and crops, as well as an overall quantification of the described parameters; in order to enable a reliable estimation of PPP residues in pollen, nectar and other bee matrices
Recent trends in the analysis of honey constituents
ProducciĂłn CientĂficaThe main goal of this article is to present an overview of the analytical methodologies employed in recent years (2015–2021) to determine several honey constituents, and, specifically, those with health-promoting effects and nutritional value, like phenolic compounds, sugars, amino acids and proteins, vitamins, lipids, minerals, and organic acids. The review is structured according to the different families of compounds, and they will be discussed along with the main extraction and analytical techniques used for their determination. Phenolic compounds, sugars and amino acids have been the main compounds determined in honey. The analytical methods (sample treatment and determination techniques) are strongly dependent on the compound. Nevertheless, it can be concluded that high-performance liquid chromatography was predominantly selected for determining honey constituents; while, in relation to the sample treatment, the preferred option was a dilution of the honey with water or a buffer.Ministerio de EconomĂa y Competitividad y el Instituto Nacional de InvestigaciĂłn y TecnologĂa Agraria y Alimentaria (project numbers RTA 2015-00013-C03-03
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