共查询到20条相似文献,搜索用时 93 毫秒
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为了应用电子自旋共振(ESR)波谱技术检测辐照葡萄,以葡萄皮、葡萄柄和葡萄籽为试验材料,研究其在0~10.0 kGy剂量范围ESR波谱特征变化以及辐照剂量与信号强度的关系。结果表明: 葡萄皮、葡萄柄和葡萄籽辐照后ESR波谱均有明显的区别,信号强度均随辐照剂量增加而增大。葡萄柄的辐照剂量检出限最低(0.25 kGy),是鉴定葡萄样品是否经过辐照的理想材料。通过比较葡萄皮、葡萄柄和葡萄籽剂量效应曲线得出葡萄柄拟合曲线最为准确(R2=0.9943)。3种辐照试验材料在贮藏期(15 d)内信号强度均有不同程度的衰减,辐照葡萄皮信号强度衰减最为剧烈(衰减80%)。研究结果为ESR波谱技术在辐照葡萄检测中的应用提供了技术依据。 相似文献
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氮离子束与γ射线辐照日本晴和“9311”水稻突变体库的筛选 总被引:1,自引:1,他引:1
利用氮离子束和γ射线辐照处理粳稻日本晴和籼稻"9311",经过M1代损伤鉴定、M2代筛选和M3代重复鉴定,分别得到了740份和666份日本晴突变体,571份和781份"9311"突变体。获得的突变体发生了叶片、茎秆、穗部和籽粒、生理等性状的突变。在氮离子束辐照处理中,日本晴和"9311"分别在5.0×1016N+/cm2和2.5×1016N+/cm2剂量辐照时获得高突变率,为6.44%和6.38%;γ射线辐照处理中,2种材料均在150Gy剂量辐照时获得高突变率,分别为5.68%和9.44%。在本试验中,各高突变率群体均为辐照当代损伤最低的群体。新构建的突变体库将为水稻功能基因组学研究提供较好的基础材料。 相似文献
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本试验用1kGy~(60)Coγ射线辐照的蘑菇加工罐头,并与鲜蘑菇和盐水蘑菇加工的罐头进行比较。结果表明:辐照蘑菇加工罐头的风味与鲜蘑菇加工的罐头一样味美,口感更佳,优于盐水蘑菇加工的罐头。分析蛋白质、脂肪、纤维素、磷和钙含量表明,主要养分无明显损失。分析17种氨基酸含量表明,辐照蘑菇罐头的子实体和汁液的谷氨酸含量均高于盐水蘑菇罐头,接近鲜菇罐头。重金属和致病菌检定结果符合食品卫生标准。但辐照罐头蘑菇色较暗,贮存两年后菇体/汁液的比率低于盐水蘑菇罐头。 相似文献
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Marchioni E Horvatovich P Charon H Kuntz F 《Journal of agricultural and food chemistry》2005,53(10):3774-3778
Protocols EN 1786 and EN 1788 for the detection of irradiated food by electron spin resonance spectroscopy (ESR) and thermoluminescence (TL) were not conceived for the detection of irradiated ingredients included in low concentration in nonirradiated food. An enzymatic hydrolysis method, realized at 55 degrees C, has been developed for the extraction of silicate minerals and bone fragments. When followed by a purification of the extracts by an aqueous solution of sodium polytungstate, this method made it possible to detect very low inclusions of irradiated spices (0.05%, wt/wt by TL) included in various meals (cheeses and precooked meals). Even for food containing together two ingredients (spices and mechanically recovered meat), it was possible to detect and identify them simultaneously. 相似文献
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为了提高热塑性淀粉基薄膜的力学性能,采用0、10、20、30、40、50 kGy 6个剂量的~(60)Co-γ射线对玉米淀粉进行辐照处理,研究辐照对玉米淀粉结构、颗粒尺寸的影响;并以辐照玉米淀粉为原材料,采用挤出造粒、熔融吹塑法制备热塑性辐照玉米淀粉薄膜,研究辐照剂量对热塑性薄膜力学性能、表面形貌的影响。结果表明,~(60)Co-γ射线能够有效破坏玉米淀粉分子内、分子间氢键,降低玉米淀粉的刚性;能够有效减小玉米淀粉的颗粒尺寸,增加玉米淀粉的加工流动性。随着辐照剂量的增加,热塑性辐照玉米淀粉薄膜的力学性能不断增加;未熔融颗粒不断减少,表面形貌更加均匀、平整。综合考虑热塑性辐照玉米淀粉薄膜的力学性能和钴源能耗,40kGy剂量辐照的玉米淀粉制备的热塑性淀粉基降解薄膜更具有实用价值。本研究结果为辐照玉米淀粉制造热塑性降解薄膜提供了理论依据和实际参考。 相似文献
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授粉方法对克服百合‘cordelia’×毛百合远缘杂交障碍的影响 总被引:1,自引:0,他引:1
研究了辐照花粉辅助授粉、杂交液辅助授粉及切割花柱授粉等措施对克服百合‘cordelia’(♀)×毛百合远缘杂交障碍的影响。结果表明:采用普通柱头授粉能够获得许多膨大果实和饱满种子,表明该杂交组合为亲合性组合。用经1000Gy或2500Gy剂量60Co辐照的母本花粉进行辅助授粉明显地提高了座果率和饱满种子结籽数,表明两种剂量的辐照花粉辅助授粉均能有效地克服该组合的杂交障碍。结籽数的提高有利于后续的选育工作。采用杂交液辅助授粉,座果率和饱满种子结籽数有所提高。而切割花柱授粉明显地减少了座果率和结籽数,表明该方法不适合于克服‘cordelia’(♀)×毛百合杂交障碍。 相似文献
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吸收剂量、贮藏时间及贮藏温度对辐照牛肉中2-十二烷基环丁酮的影响 总被引:2,自引:1,他引:1
分析了辐照牛肉中辐解产物2-十二烷基环丁酮在不同的吸收剂量(0.5~10.0kGy)、贮藏时间(0-40d)及贮藏温度(-20℃~4℃)下的变化规律。采用硅胶层析柱-气相色谱/质谱联用技术萃取分离并检测。结果表明,2-十二烷基环丁酮的浓度与吸收剂量呈线性正相关,随着贮藏时间延长其含量减少,贮藏温度对其没有显著影响。利用2-十二烷基环丁酮可鉴定牛肉是否经过辐照,在已知贮藏温度和时间的条件下,可评估辐照牛肉的大约吸收剂量范围。 相似文献
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Usually spices are identified morphologically using simple methods like magnifying glasses or microscopic instruments. On the other hand, molecular biological methods like the polymerase chain reaction (PCR) enable an accurate and specific detection also in complex matrices. Generally, the origins of spices are plants with diverse genetic backgrounds and relationships. The processing methods used for the production of spices are complex and individual. Consequently, the development of a reliable DNA-based method for spice analysis is a challenging intention. However, once established, this method will be easily adapted to less difficult food matrices. In the current study, several alternative methods for the isolation of DNA from spices have been developed and evaluated in detail with regard to (i) its purity (photometric), (ii) yield (fluorimetric methods), and (iii) its amplifiability (PCR). Whole genome amplification methods were used to preamplify isolates to improve the ratio between amplifiable DNA and inhibiting substances. Specific primer sets were designed, and the PCR conditions were optimized to detect 18 spices selectively. Assays of self-made spice mixtures were performed to proof the applicability of the developed methods. 相似文献
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<正> The main objective of the present research was to determine the influence of gamma irradiations on wheat,the diet of the grain weevil,using as parameters of the longevity and reproduction of this insect.The doses of 60Coγ-rays applied to wheat grains were O(control),125,250,500,1000,2000,and 4000 Gy,at a dose rate of 3000 Gy per hour.The longevity,expressed as life-expectancy in days,and the reproduction expressed as the number of F1 adults,showed no differences up to the dose of 2000 Gy.The wheat irradiated with the dose of 4000 Gy induced a lower life-expectancy of the insects fed with irradiated wheat and a smaller number of insects of the F1 generation. 相似文献
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