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101.
《Journal of Cereal Science》1996,24(1):47-53
The contribution of grain protein to the malting quality of barley (Hordeum vulgareL.) was investigated by comparing the hordein composition and the malting quality in barley produced under a range of field conditions. Two malting cultivars, Schooner and Arapiles, and one feed cultivar, Galleon, were grown under five nitrogen regimes in each of two years. Hordein composition of the grain was determined at maturity using a combination of sodium dodecyl sulphate-polacrylamide gel electrophoresis and laser densitometry. Malt extract was determined on all samples after micromalting. Variation in growth conditions resulted in a wide range of grain protein contents and malt extract values, as well as variation in the proportions of the individual B, C and D hordeins in the grain. D hordein in particular varied over a 10-fold range. High levels of all protein fractions were associated with low malt extract. Total protein, as expected, displayed a strong, negative correlation with malt extract. The relationship was cultivar specific and separate regression lines were generated for each cultivar. Of the individual hordein fractions, D hordein displayed the strongest negative correlation with malt extract and its relationship to malt extract was independent of cultivar. A consistent relationship between D hordein and malt extract was observed across seasons, treatments and cultivars that was indicative of a causal relationship between D hordein and malting quality. D hordein therefore offers an alternative measurement to total protein for the prediction of malting quality over a wide range of environmental conditions and cultivars. 相似文献
102.
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104.
《Journal of Cereal Science》2005,41(1):95-106
During the germination of seeds, storage proteins are degraded and the resulting amino acids are utilized by the growing seedling. In barley, this process is commercially important because it forms the basis for the malting and brewing industries. In this study, barleys and malts were mashed in the presence of compounds that specifically inhibited the four common proteinase classes. The efficacies of the proteinases in solubilizing proteins were in the order cysteine≈metallo>aspartic>serine≈0, which roughly reflected how the inhibitors affected the mash endoproteolytic activities. It was previously believed that only the cysteine enzymes were involved. All four enzyme classes affected the free amino nitrogen concentration but none altered any of the other measured wort characteristics. With either single inhibitors or inhibitor mixtures, the effect of pH was as expected, based on earlier studies that indicated that cysteine and aspartic proteinases were most active at low pH values and the metalloproteinases were only active at high pH. At the North American commercial mashing pH of 6.0, about one third of the soluble protein of a typical wort came from ungerminated barley, half was solubilized during malting and the remaining 22% was released during mashing. 相似文献
105.
106.
《Field Crops Research》2005,91(2-3):287-296
Barley (Hordeum vulgare) and wheat (Triticum aestivum) are similar crops that can be grown in the arid regions of southwestern Asia. Generally, barley is favored over wheat in drier areas. However, the quantitative basis for the relative advantage of each crop under differing growing conditions has not been resolved. This study was undertaken to compare the two crops using the same model structure. A wheat model developed for southwestern Asia was readily adapted to simulate barley. Simulations of barley crops proved to be robust over a range of environments. Comparison of simulated yields in a number of environments showed that the critical difference between species was the cumulative effect of plant development traits that allowed barley to mature much earlier than wheat. Consequently, early maturity of barley in contrast to wheat often allowed barley to complete its growing cycle before water-deficit conditions developed in the spring. There was, however, little or no yield advantage for barley in seasons of high rainfall. Also, rare seasons with significant rainfall after barley matured allowed wheat to actually produce the greater yield. These simulation results indicated that development traits are crucial in the interaction between crop yield and exposure to water deficits at the end of the growing season. 相似文献
107.
《Field Crops Research》2004,86(1):67-80
Mungbean (Vigna radiata L.), as a dryland grain legume, is exposed to varying timing and severity of water deficit, which results in variability in grain yield, nitrogen accumulation and grain quality. In this field study, mungbean crops were exposed to varying timing and severity of water deficit in order to examine: (1) contribution of the second flush of pods to final grain yield with variable timing of relief from water deficit, (2) the sensitivity to water deficit of the accumulation of biomass and nitrogen (N) and its partitioning to grain, and (3) how the timing of water deficit affects the pattern of harvest index (HI) increase through pod filling. The results showed that the contribution of the second flush to final yield is highly variable (1–56%) and can be considerable, especially where mid-season stress is relieved at early pod filling. The capacity to produce a second flush of pods did not compensate fully for yield reduction due to water stress. Relief from mid-season stress also resulted in continued leaf production, N2 fixation and vegetative biomass accumulation during pod filling. Despite the wide variation in the degree of change in vegetative biomass and N during pod filling, there were strong relationships between grain yield and net-above-ground biomass at maturity, and grain N and above-ground N at maturity. Only in the extreme situations were HI and nitrogen HI affected noticeably. In those treatments where there was a large second flush of pods, there was a pronounced biphasic pattern to pod number production, with HI also progressing through two distinct phases of increase separated by a plateau. The proportion of grain yield contributed to by biomass produced before pod filling varied from 0 to 61% with the contribution greatest under terminal water deficit. There was a larger effect of water deficit on N accumulation, and hence N2 fixation, than on biomass accumulation. The study confirmed the applicability of a number of long-standing physiological concepts to the analysis of the effect of water deficit on mungbean, but also highlighted the difficulty of accounting for timing effects of water deficit where second flushes of pods alter canopy development, biomass and yield accumulation, and N dynamics. 相似文献
108.
Landscape Ecology - Urban integration has exacerbated the spreading of urban heat islands (UHIs) across cities. Blue/green landscapes embedded within urban areas, behaving as cool islands... 相似文献
109.
《Journal of Cereal Science》2001,34(1):1-17
Starch makes an important contribution to food structure and hence quality. Often there is a need to modify the behaviour of starch in food materials. One approach is to use knowledge of the physical chemistry of starch to modify component interactions and hence change behaviour. In this review we examine recent research on the phase behaviour and dynamics of starch relevant to this approach. 相似文献
110.
Irene Sartini Beata Łebkowska-Wieruszewska Andrzej Lisowski Amnart Poapolathep Helen Owen Mario Giorgi 《Journal of veterinary pharmacology and therapeutics》2020,43(1):26-32
The purpose of this study was two-fold: I) to determine the pharmacokinetic profile of meloxicam (MLX) in geese after intravenous (IV) and oral (PO) administration and II) to assess tissue residues in muscle, heart, liver, lung, and kidney. Ten clinically normal female Bilgorajska geese were divided into two groups (treated, n = 8; control, n = 2). Group 1 underwent a 3-phase parallel study with a 1-week washout period. In phase I, animals received MLX (0.5 mg/kg) by IV administration; the blood was collected up to 48 hr. In phases II and III geese were treated orally at the same dosage for the collection of blood and tissue samples, respectively. Group 2 served as control. After the extraction procedure, a validated HPLC method with UV detection was used for plasma and organ analysis. The plasma concentrations were quantifiable up to 24 hr after both the administrations. The elimination phase of MLX from plasma was similar in both the administration groups. The clearance was slow (0.00975 L/hr*Kg), the volume of distribution small (0.0487 L/kg), and the IV half-life was 5.06 ± 2.32 hr. The average absolute PO bioavailability was 64.2 ± 24.0%. Residues of MLX were lower than the LOQ (0.1 µg/kg) in any tested tissue and at any collection time. The dosage used in this study achieved the plasma concentration, which provides analgesia in Hispaniolan Amazon parrots for 5 out of 24 hr after PO administration. MLX tissue concentrations were below the LOD of the assay in tissue (0.03 µg/ml). A more sensitive technique might be necessary to determine likely residue concentrations in tissue. 相似文献