共查询到18条相似文献,搜索用时 156 毫秒
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用(60)~(Co)γ射线辐照无核绿葡萄干,延长其保藏期的试验结果表明,杀灭葡萄干表面上虫卵的适宜剂量为3.5kGy;杀死葡萄干内已孵化幼虫的有效剂量为3.0kGy。经辐照处理过的无核绿葡萄干,在常温下可保藏8个月以上,达到在新疆地区安全保藏越夏的目的。辐照无核绿葡萄干不产生不良变化的临界剂量为5.0kGy。2.0—4.0kGy辐照葡萄干,其主要营养成分未发生明显的变化。应用1.8—60.0kGy剂量辐照后的葡萄干,未发现有感生放射性核素及放射性污染。综合研究表明,无核绿葡萄干用3.5kGy剂量辐照符合卫生安全标准。 相似文献
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贮粮害虫玉米象(Sitophilus zeamais)、豌豆象(Bruchus pisorum)致死剂量的研究 总被引:1,自引:2,他引:1
本试验对粮食仓贮害虫玉米象(Sitophilus zeamais)和豌豆象(Bruchuspisorum)的辐照致死剂量进行了研究,试验所用材料皆为成虫,辐照剂量为0.1—3.0kGy。结果表明:0.6—0.8kGy辐照玉米象(Sitophilus zeamais)成虫,照后20天左右就能完全将其杀死:0.8—1.0kGy辐照豌豆象成虫.照后15—30天亦能完全将其杀死。经0.2—2.0kGy辐照的玉米、小麦和大米,其营养成份没有发生明显的变化。 相似文献
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γ辐照对苹果品质的影响 总被引:1,自引:2,他引:1
本文研究了γ辐照对苹果硬度、果胶酶活力,细胞超微结构以及挥发性成份的影响。结果表明,辐照苹果的硬度在短期(辐照后2天)内随辐照剂量的增加而下降,但是,随着贮藏时间的延长,0.3—0.9kGy辐照的苹果,其硬度比对照高。1.5kGy以下剂量辐照的苹果,其果胶甲脂酶和多聚半乳糖醛酸酶的活性与果肉硬度呈负相关,而高剂量(2.0kGy)辐照,则导致苹果的软化,使果肉细胞的细胞质和核质聚集形成颗粒,细胞膜断裂,核膜膨大,组织透性增大。0.7—2.0kGy辐照,减少了苹果挥发性成份的种类,其中四种主要成份,即乙酸乙酯、丁醇、乙酸丁酯和乙酸己酯的含量也减少,2.0kGy辐照,还使后两种主要成份完全消失。但同样剂量辐照,对上述四种物质的纯品则没有影响。 相似文献
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大豆蛋白粉的辐照灭菌研究 总被引:5,自引:3,他引:2
研究了60Coγ射线辐照大豆蛋白粉的杀菌效果与对大豆蛋白粉的主要营养成分、尿素酶(脲酶)活性以及感官品质的影响。结果表明,2.0kGy辐照对大豆蛋白粉中菌落总数、大肠菌群的杀菌率达70%,对霉菌的杀菌率达53%;4.0kGy辐照杀菌率达95%;经6.0kGy辐照处理后,杀菌率达到97%以上,辐照的大豆蛋白粉样品中微生物指标均达到食品卫生国家标准;8.0kGy辐照杀菌率达到100%。与对照相比,剂量为2.0~8.0kGy的辐照对大豆蛋白粉中蛋白质、粗纤维、总糖、氨基酸(除Leu)含量的影响不明显;而粗脂肪及卵磷脂的含量有极显著变化(P<0.01),尤其是卵磷脂的含量显著增加,异黄酮的含量则显著降低(P<0.05);辐照对大豆蛋白粉中尿素酶活性没有显著影响;6.0kGy以下剂量辐照对大豆蛋白粉色泽、气味、口感无明显改变。综合试验结果,确定了大豆蛋白粉辐照杀菌的适宜工艺剂量范围为3.0~5.0kGy。 相似文献
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辐照是一种非常有效的食品杀菌保鲜技术,近年来在即食肉制品保鲜方面的应用逐渐引起了人们的关注。为了探讨γ辐照技术对猪肉火腿肠的杀菌保鲜效果,试验采用1、3、5、7、9 k Gy 5个剂量分别对火腿肠进行辐照处理,辐照结束后样品在4℃条件下冷藏,然后跟踪测定其在冷藏过程中脂肪和蛋白质氧化、颜色、p H值、挥发性盐基氮(total volatile basic nitrogen,TVB-N)以及菌落总数的变化,分析不同剂量辐照处理对火腿肠保鲜效果的影响。结果表明,辐照可以显著降低火腿肠脂肪和蛋白质的氧化稳定性,促进其在储藏过程中的氧化。1 k Gy剂量辐照对火腿肠的色泽影响不显著;3~9 k Gy剂量辐照,可以使样品的红度值(a*值)显著降低、亮度值(L*值)显著升高(P0.05),而在冷藏过程中a*值与L*值均随储藏时间的延长而降低,且高剂量辐照组要比低剂量组降低更快一些。火腿肠p H值受辐照影响不显著(P0.05),且在冷藏过程中所有处理组火腿肠的p H值变化也不显著,均在6.0~6.5范围内。5 k Gy剂量辐照即可对猪肉火腿肠中的微生物起到有效抑制作用。 相似文献
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为研究食品基质对γ-辐照杀菌效果的影响,本试验以英诺克李斯特菌(Listeria Innocua)为试材,采用lgN-D线性回归分析,建立活菌数-剂量的拟合方程,获得D10 值;利用D10值表征无菌水环境下γ-射线和电子束辐照的吸收剂量差异,以及不同γ-射线吸收剂量、糖浓度、盐浓度对英诺克李斯特菌杀菌效果的影响。结果表明,当辐照在无菌水液体环境下时,γ-射线的D10值均小于电子束,分别为0.788和0.872 kGy,表明γ-射线的杀菌效果更好;在γ-射线辐照下,杀灭生理盐水(0.85% NaCI)中英诺克李斯特菌的D10值与无菌水无明显差别,随着盐浓度的增加,D10值呈先增加后减少的趋势,其中在3%和5%盐浓度下的D10值分别为0.709和0.730 kGy,明显低于无菌水组;杀灭糖溶液中英诺克李斯特菌的D10值明显高于无菌水组,随着糖浓度的增加,D10值先升高后降低,其中5%糖溶液的D10值最大,为1.133 kGy。说明盐溶液对杀菌有协同作用,而糖溶液对杀菌有抵抗作用。本研究结果为进一步探索辐照杀菌机制,降低辐照剂量成本,提升产品品质提供了一定的参考。 相似文献
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Drying oils, such as linseed oil and tung oil, have the potential as coating materials to improve barrier properties of biobased packaging films. Oil drying is a chemical reaction in which polyunsaturated fatty acids undergo autoxidation. During drying, oils polymerize and form water-resistant films. However, drying rates tend to be too slow for practical applications. Metal driers are used in the paint industry to accelerate drying, but often driers are not safe for food contact. The objective of this work was to investigate the effect of ionizing radiation on the oxidation or drying rate of drying oils. The effect of irradiation dose on the drying rate of linseed and tung oils was monitored by FTIR spectroscopy. The peak at 3010 cm (-1) was found to be a useful index of oxidation rate. The decrease in peak intensity with time was fitted with exponential functions of the form Abs = Abs 0 exp (- t/ k), where Abs 0 is the initial absorbance and 1/ k is the rate constant for the oxidation process. Values for k were 9.91 ( R (2) = 0.98), 6.59 ( R (2) = 0.95)n and 6.44 ( R (2) = 0.97) for radiation levels of 0, 50, and 100 kGy, respectively. The k values suggested that the oxidation rate increased as the radiation dose increased from 0 to 50 kGy. A further increase to 100 kGy had only a limited effect. 相似文献
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The effect of electron-beam ionizing radiation stress and storage on mango fruit antioxidant compounds was evaluated in a dose range of 1-3.1 kGy. Phenolic high-performance liquid chromatography (HPLC) profiles were not affected right after the irradiation process; however, an increase in flavonol constituents was observed after 18 days in storage (3.1 kGy). Total phenolics by the Folin Ciocalteu method and antioxidant capacity (ORAC) were not affected, while reduced ascorbic acid decreased approximately 50-54% during storage (>/=1.5 kGy). No major changes in carotenoid HPLC profiles indicated a delay in ripening of irradiated mangoes (1-3.1 kGy) compared to nonirradiated fruits. However, irradiation dose >/=1.5 kGy induced flesh pitting due to localized tissue death. A summary of the potential roles of reactive oxygen species generated by the irradiation stress on different antioxidant constituents of mango fruits is presented. 相似文献
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宠物干粮食品辐照杀菌工艺参数的确定 总被引:4,自引:1,他引:3
依照国内外学者的研究结果和国际辐照饲料工艺规范的规定,研究了宠物干粮食品辐照杀菌工艺,确定了各项技术指标,并就主要技术指标的确定依据进行了阐述。该技术规定:辐照前宠物干粮食品细菌总数≤5×104 MPN/100g,霉菌≤4.5×104 CFU/g,沙门氏菌≤1×103 CFU/25g,辐照后细菌总数≤1000 CFU/g,大肠菌群≤30 MPN/100g,霉菌≤25 CFU/g,沙门氏菌不得检出,宠物干粮食品辐照杀菌的最低有效剂量为4.0 kGy,最高耐受剂量为15.0 kGy。辐照产品箱中最小吸收剂量应不小于最低有效剂量,最大吸收剂量应不大于产品的最高耐受剂量。 相似文献
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Girennavar B Jayaprakasha GK Mclin SE Maxim J Yoo KS Patil BS 《Journal of agricultural and food chemistry》2008,56(22):10941-10946
Phytochemical levels in fruits and vegetables can be affected by several postharvest factors. In the present study, the effect of electron-beam (E-beam) irradiation was studied on grapefruit bioactive compounds. 'Rio Red' and 'Marsh White' grapefruits were irradiated with E-beam at 0, 1.0, 2.5, 5.0, and 10.0 kGy. Changes of various bioactive compounds, such as vitamin C, flavonoids, carotenoids, furocoumarins, and limonoids, were measured. The acidity decreased slightly with an increasing E-beam dose, whereas the total soluble solids were increased. Irradiation did not affect the vitamin C content at 1 kGy; however, doses beyond 1 kGy significantly reduced the vitamin C content. Lycopene and beta-carotene did not change significantly from the irradiation. Lycopene levels decreased as the E-beam dose increased, while the beta-carotene content slightly increased. Dihydroxybergamottin levels exhibited a decreasing trend, while the bergamottin content did not change. Naringin, a major flavonoid of grapefruit, showed a significant increase over the control at 10 kGy in both 'Rio Red' and 'Marsh White'. Nomilin continued to decrease with an increasing dose of E-beam irradiation, while limonin levels remained the same at all of the doses. Low-dose E-beam irradiation has very little effect on the bioactive compounds and offers a safe alternative to existing postharvest treatments for the disinfection and decontamination of grapefruits. 相似文献
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60Co辐照对白灵菇采后低温贮藏的影响 总被引:3,自引:0,他引:3
以0.8、1.2、1.6和2.0kGy60Coγ射线辐照白灵菇,在4℃下贮藏保鲜。结果表明,经过1.2kGy辐照处理的白灵菇维持了最高的可溶性蛋白质含量和最大的硬度,贮藏保鲜时间最长。白灵菇在贮藏期间的硬度越大,其可溶性蛋白的含量也越高,且二者之间存在显著的相关性。辐照会加大白灵菇的细胞膜透性,破坏细胞膜结构,剂量过大反而会加速营养成分降解和腐烂。 相似文献