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41.
The partial substitution of humic acid derivatives for fertilizer did not improve yield, specific gravity or boiling, chipping and storage quality in Kennebec and Sebago potatoes in Ontario. 相似文献
42.
Jill Hughes Hamish A. Collin Angela Tregova A. Brian Tomsett Richard Cosstick Meriel G. Jones 《Plant foods for human nutrition (Dordrecht, Netherlands)》2006,61(2):78-82
Garlic (Allium sativum) cloves were stored at ambient temperature and 4 °C for periods up to six months to establish the effect of position of the individual clove within the bulb and of low storage temperature on the composition of several flavours precursors and other organic sulphur compounds, measured by gradient High Pressure Liquid Chromatography. Levels of alliin, γ glutamyl allyl cysteine sulphoxide and γ glutamyl isoallyl cysteine sulphoxide were statistically significantly higher in outer than in inner cloves. There was no statistically significant change in levels of alliin, the major flavour precursor, in cloves stored at 4 °C, remaining in the average range 17.5±3.8–39.1±7.5 mM. However, isoalliin increased significantly during storage at 4 °C, rising from an average 0.6±0.2 mM (outer cloves)—0.7±0.4 mM (inner cloves) to 7.1±1.7 mM (outer cloves)—4.1±0.7 mM (inner cloves). A decline in other sulphur-containing compounds, most likely to be the peptides γ-glutamyl allylcysteine sulphoxide and γ-glutamyl isoallylcysteine sulphoxide, occurred at the same time and possibly contributed to the increase in the flavour precursor compounds. The degree of chemical changes during storage will be of interest to the food and pharmaceutical industries. 相似文献
43.
Synthesis and sensorial properties of mercaptoaldehydes 总被引:1,自引:0,他引:1
Mercaptoalcohols and mercaptoketones have been described in the past decade as relevant character-impact compounds in various food products. On the other hand, very little is known of mercaptoaldehydes. Only 3-mercapto-2-methylpentanal and 3-mercaptohexanal have been found in onions and beef liver, respectively. The aim of this work was to synthesize 13 mercaptoaldehydes not commercially available by combinatorial chemistry. Chromatographic analyses of the mixture allowed the determination of their retention indices and mass spectroscopy fragments for further identification in foods. Gas chromatography-olfactometry demonstrated how some of them are characterized by unusual odor and very low perception threshold. 相似文献
44.
为获得对水稻纹枯病有生防潜力的菌株,从湖北省恩施土家族苗族自治州植物根际土壤中分离获得菌株,筛选对水稻纹枯病菌有拮抗作用的菌株,并测定其发酵液的抑菌活性、抑菌谱及生物学特性;基于形态学特征、生理生化特征及分子生物学特征对其进行分类鉴定,并通过离体叶片、室内盆栽和田间试验进一步评价其生防潜力。结果显示,从根际土壤中共分离获得162株菌株,其中生防菌株E12对水稻纹枯病菌的抑制率最高,达94.93%,且该菌株对常见的12种植物病原菌均有抑制作用,抑制率在59.84%~93.14%之间;生防菌株E12能分泌蛋白酶、嗜铁素和淀粉酶,具有固氮及形成生物被膜的能力;结合形态学特征、生理生化特征及分子生物学特征,将菌株E12鉴定为越南伯克霍尔德氏菌Burkholderia vietnamiensis;生防菌株E12处理离体水稻叶片后,其相对病斑长度较对照显著减小,对水稻纹枯病的室内盆栽和田间防治效果分别为62.51%和67.78%。表明越南伯克霍尔德氏菌E12在防控水稻纹枯病方面有较好的潜力。 相似文献
45.
AIM: To determine the rate of transmission of Mycobacterium avium subsp paratuberculosis (M. ptb) from hind to fetus in utero, and the risk of transmission from dam to fawn via infected colostrum and milk in subclinically affected red deer hinds. METHODS: Hinds were sourced from farms in Otago or Southland and selected for the study if they were positive to the immunoglobulin G1 (IgG1) modified enzyme-linked immunosorbent assay (ELISA) (Paralisa) and exhibited no clinical signs of Johne's disease. The hinds (n=35) were sent to a deer slaughter premises (DSP; n=31) or were killed on-farm (n=4). All post-mortem samples were collected from the fetus first and then from the dam, taking care to avoid cross contamination between samples. Fresh samples (n=185) were collected for culture, and tissue samples (n=72) were collected from 24 hinds and their fetuses for histopathological examination. RESULTS: A total of 24/35 hinds selected were suitable for inclusion in the study. Eighteen of these pregnant hinds were culture-positive for M. ptb, and 14 of these had culture-positive fetuses, representing a transmission rate of 78% (95% confidence interval (CI) =0.58–0.98) from dam to fetus. Of the 16 mammary glands sampled, 11 (69%) were culture-positive for M. ptb while 12/15 (80%) mammary lymph nodes sampled were also culture-positive. CONCLUSIONS: This study demonstrated a high rate of transmission of M. ptb from dam to fetus in red deer, and a potential risk of transmission to fawns suckling from mothers that are subclinically affected with Johne's disease. 相似文献
46.
RG Cooper 《New Zealand veterinary journal》2013,61(3):130-133
AIM: To report the infestation of Thysanoptera (Limothrips denticornis) on ostriches (Struthio camelus) and to determine their relative density. METHODS: A farm in Poland was studied on which ostriches aged 14 months were severely infested with L. denticornis (thrips). Thrips were collected and their density on the neck, torso and legs (10 cm2) of 85 ostriches determined at 0600, 1200 and 1800 h, respectively, over 7 days. At the same times, apparent densities of thrips/m2 were determined in adjacent grassy areas (120 m2) on a muslin cloth impregnated with permethrin. Thrips were mounted onto slides in Hoyer's medium, for identification. RESULTS: The apparent density of thrips was greatest at 1200 h, and was greater on the neck than the torso and legs (p=0.03). In adjacent surroundings, densities were also highest at 1200 h (mean 199 (SE 9.3) thrips/m2) and were similar to the maximum densities recorded on the necks of ostriches at that time (mean 205 (SE 6.4) thrips/m2). Ostriches engaged in excessive preening and attempted to scratch their head/neck with their feet. Numerous small, pale red papules were observed on the skin. Observations of periorbital cellulitis, conjunctivitis, blepharitis, watery discharge, inflammation, and sclerotic discolouration were noted in 65 ostriches. CONCLUSION: Observations were commensurate with L. denticornis infestation. CLINICAL RELEVANCE: Infestation may exacerbate stress levels and subsequently lead to a reduction in feed intake and performance. The infestation and subsequent irritation from thrips impacts negatively on the general health of ostriches by damaging skin and irritating eyes. 相似文献
47.
Extract Listeria monocytogenes is widely distributed in the environment of farm animals. It is found in soil, faeces and nasal secretions of healthy animals, water troughs and animal feeds. Under certain conditions it becomes pathogenic, causing serious disease in cattle and sheep. Most commonly it causes meningoencephalitis but, on occasion, septicaemic listeriosis results in abortion, and more recently it has been associated with gastroenteritis. 相似文献
48.
49.
Forty-one thiols, mainly β-sulfanylalkyl acetates, β-sulfanylalkyl alcohols, and β-sulfanylalkyl carbonyls, were recently evidenced in hop. In a beer hopped with the Tomahawk cultivar, most of them were found at higher levels than expected. The aim of the present work was to investigate the polyfunctional thiols in beers hopped with different varieties. A few thiols proved not to come only from hop (mainly 2-sulfanylethyl acetate, μg/L levels, and 1-sulfanylpentan-3-one and 1-sulfanylpentan-3-ol, ng/L levels, internal standard (IST) equivalents). The thiol profile of Saaz-hopped beer proved similar to that of the reference beer produced without hop. A high level of 3-sulfanyloctan-1-ol emerged as an indicator of the use of Tomahawk hop (140 ng/L, IST equivalents; FD (flavor dilution) = 65536). In both Cascade- and Tomahawk-hopped beers, 3-sulfanylhexan-1-ol and 3-sulfanylheptan-1-ol were smelled at high flavor dilutions, although only for the latter, significant amounts of the unreduced 3-sulfanylheptanal were found in hop. As already claimed for hop authentication, 3-sulfanyl-4-methylpentan-1-ol remains a good marker of Nelson Sauvin-hopped beers (548 ng/L, IST equivalents; FD = 65536), together with 4-sulfanyl-4-methylpentan-2-one (128 ng/L, FD = 4096). As illustrated by the huge production occurring during fermentation, accurate prediction of hop varietal impact requires quantitating thiol adducts in hop. S-3-(1-Hydroxyhexyl)cysteine was evidenced here for the first time in Cascade hop. 相似文献
50.
Trans-Piceid and trans-resveratrol contents of hop cones, hop pellets, CO2 extracts, and spent hop from American varieties (harvest 2004) were determined by reverse-phase high-performance liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry [RP-HPLC-APCI(+)-MS/MS]. Pelletization induced strong stilbene degradation in some cultivars. Similarly, 1 year of storage at 4 degrees C led to a huge loss of trans-piceid, especially in the case of hop cones (much faster than in model media, although well protected from light and oxygen). Therefore, after 8 months of storage, the overall stilbene content was in the same range whatever the conditioned form. Absent in fresh hop cones or pellets, cis-resveratrol was released from cis-piceid in all stored samples. On the other hand, no delta-viniferin was detected despite it is present in light-protected model media spiked with trans-piceid. Because supercritical carbon dioxide proved inefficient for recovering resveratrol and piceid from pellets, spent hop emerged as the most interesting material for subsequent specific stilbene extraction. 相似文献