共查询到20条相似文献,搜索用时 9 毫秒
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研究了臭氧处理对高水分稻谷品质与微生物量的影响,并根据臭氧处理后稻谷储藏过程中霉变、发芽率与脂肪酸值的变化规律,优化了储藏工艺条件。结果表明:臭氧处理对稻谷感官品质和发芽率没有影响,脂肪酸值略有增加,微生物量明显降低。臭氧处理组稻谷在不同温度储藏,随着时间的延长,与对照相比,霉变时间呈不同程度的延迟,发芽率在同温度时呈基本一致的下降趋势,而脂肪酸值增加,幅度与臭氧处理质量浓度和储藏温度有关,15℃时,呈上升趋势,且臭氧处理质量浓度越高,增加越快,而25、35℃储藏,呈先上升后下降趋势,95 mg/kg臭氧处理的稻谷尤为明显。进一步的SPSS分析表明,稻谷发芽率与储藏温度和时间呈显著的二元线性关系,脂肪酸值与臭氧处理质量浓度、储藏温度和时间呈显著的三元线性关系。因此臭氧处理高水分稻谷储藏优化的工艺条件为臭氧处理质量浓度55 mg/kg,储藏温度15℃,储藏时间60 d。 相似文献
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Kinetics of liquid water sorption by soybean (Glycine max) and pigeonpea (Cajanus cajan) seeds was studied at several temperatures. The data could be accurately correlated in terms of an empirical model involving a single rate constant. The temperature dependence of the rate constant followed Arrhenius relation. Swelling of grains due to water sorption was slightly less than the volume of water imbibed. This loss related to the energy of activation of the water sorption process. 相似文献
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本文介绍了一种集自动计量、充填、充(换)气、热封、卸料于一体的新型粮食气调包装机的工作原理、结构组成及设计特点。 相似文献
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稻谷的解吸和吸湿平衡水分是研究稻谷干燥机理与安全贮藏的重要参数。本文在相对湿度30%~90%范围内,采用动态法测定了温度分别为20℃、25℃、30℃、35℃时特种稻谷(黑米)吸湿的平衡水分;绘制了特种稻谷(黑米)的吸湿平衡水分曲线;分析了温度和相对湿度对平衡水分的影响;得出该品种稻谷在20℃、25℃、30℃、35℃时吸湿平衡水分与相对湿度的非线性关系方程式。 相似文献
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A. van Warners G. Lammers E. J. Stamhuis A. A. C. M. Beenackers 《Starch - St?rke》1990,42(11):427-431
The hydroxyethylation of potato starch was studied in a gas-solid system. The rate of diffusion of ethylene oxide into the granules, the solubility of ethylene oxide in native starch and the rate of reaction between gaseous ethylene oxide and alkaline starch powder were measured. The partial pressure of ethylene oxide was kept at a constant value close to atmospheric pressure, the temperature was varied between 303 and 323 K. The ratio of the ethylene oxide concentrations in the starch granules and in the gas phase. mEO, is almost independent of the water content of the granules. The dependence of EO on temperature can be described with the Van 't Hoff equation: mEO = 5.93 · 10−5 exp (33390/RT). The rate of diffusion of ethylene oxide in the granules with a narrow size distribution does not follow Fick's law but it can be described with relaxation controlled diffusion (Case II diffusion). The parameter u of this model, the front velocity, appears to depend on the persentage moisture W, present in the granules. 相似文献
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利用质构仪压缩稻谷籽粒的短轴来测定稻谷籽粒的压缩特性。测定的稻谷储藏在不同的时间与压力下。实验结果表明:当储藏时间为60 d且储藏压力由0 kPa增加到300 kPa,稻谷籽粒的破坏力由81.6 N减小到73.8 N,破坏能由8.10 mJ减小到6.27 mJ,破坏应变由0.139减小到0.117,表观接触弹性模量由171.3 MPa减小到57.7 MPa,最大接触应力由40.8 MPa减小到19.1 MPa。当稻谷储藏压力为77、100、139、200 kPa且储藏时间由0~60 d,稻谷籽粒的破坏力由81.6 N分别减小到79.6、79.1、78.2、77.0 N;破坏能由8.10 mJ分别减小到7.55、7.35、7.08、6.85 mJ;破坏应变由0.139分别减小到0.131、0.128、0.126、0.121;表观接触弹性模量由171.3 MPa分别减小到136.0、121.8、110.6、83.3 MPa;最大接触应力由41.2 MPa分别减小到35.0、32.5、30.3、15.0 MPa。结果表明储藏压力与储藏时间对稻谷籽粒的压缩特性有重要的影响。 相似文献
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玉米是我国重要的食品和饲料原料,当收获、加工和储藏等措施不当时,可能会造成黄曲霉毒素B1(aflatoxin B1,AFB1)污染玉米这一突出问题,AFB1已被国际癌症机构定为1级致癌物。尽管目前已建立了一些物理、化学和生物降解AFB1的方法,但高效、安全、经济的绿色降解方法仍很少。本研究以AFB1污染的玉米为试样,研究臭氧对玉米中AFB1的降解效果。结果表明:AFB1降解率随着臭氧质量浓度的增加和处理时间的延长而显著提高;当水分质量分数为20.37%的玉米经90 mg/L的臭氧处理40 min后,AFB1含量由77.6 μg/kg降低到21.42 μg/kg,降解率达72.4%。臭氧降解AFB1的动力学模拟结果表明,臭氧降解AFB1符合一级动力学模型。玉米中AFB1降解速率常数按以下次序递减:k90 mg/L>k65 mg/L>k40 mg/L。实验得到臭氧降解AFB1的动力学方程、反应速率常数、决定系数和半衰期,为最优地控制臭氧降解AFB1的反应条件奠定了理论和实践基础,也为臭氧降解AFB1污染玉米的应用提供了技术保障。 相似文献
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Ozone was tested against Pseudomonas fluorescens, Escherichia coli O157:H7, Leuconostoc mesenteroides , and Listeria monocytogenes. When kinetic data from a batch reactor were fitted to a dose-response model, a 2-phased linear relationship was observed. A continuous ozone reactor was developed to ensure a uniform exposure of bacterial cells to ozone and a constant concentration of ozone during the treatment. Survivors plots in the continuous system were linear initially, followed by a concave downward pattern. Exposure of bacteria to ozone at 2.5 ppm for 40 s caused 5 to 6 log decrease in count. Resistance of tested bacteria to ozone followed this descending order: E. coli O157:H7, P. fluorescens, L. mesenteroides , and L. monocytogenes. 相似文献
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本文选取南粳5055品种稻谷为实验样品,使其在6个LHT-1型回弹模量仪中储藏2个月,顶部分别加载50 kPa、100 kPa、150 kPa、200 kPa、250 kPa和300 kPa。利用Brookfield质构仪对回弹模量仪装样筒内的顶部与底部样品进行压缩实验。实验结果表明:储藏2个月,储藏压力为0-300 kPa,稻谷籽粒的最大破坏力、最大破坏能、最大破坏应变、表观接触弹性模量和最大接触应力的变化范围分别为81.58 N-3.78 N,8.10 mJ-6.27 mJ,0.1392-0.1168,71.32 MPa-57.68 MPa, 40.84 MPa-19.11 MPa。随着稻谷储藏压力的增加,最大破坏力、最大破坏能、最大破坏应变、表观接触弹性模量和最大接触应变皆减小。 相似文献
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针对硫酰氟熏蒸粮食后的残留问题,建立粮食中硫酰氟残留量检测方法。样品经非浸提顶空加热平衡方式使硫酰氟从粮食颗粒解吸至顶空,经气相色谱电子捕获检测器(GC-ECD)分析检测,以硫酰氟气体工作标准物质定量,选择顶空平衡条件80℃加热30 min。结果显示,样品中硫酰氟残留量在0.01~0.15 mg/kg范围内线性关系良好(R2=0.999 8),方法检出限(MDL)和定量限(LOQ)分别为0.000 2 mg/kg和0.000 5 mg/kg,加标回收率为83.6%~104.3%,相对标准偏差(RSD)为1.9%~9.8%(n=6)。与其他检测方法相比,本方法的非浸提顶空进样和气体形式标准物质使定量更准确、无废液产生、操作简单快捷、灵敏度更高,适用于测定粮食中硫酰氟残留量。 相似文献
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Reaction Kinetics of the Denaturation of Whey Proteins in Milk 总被引:4,自引:0,他引:4
The kinetics of the neat-induced irreversible denaturation of β-lacto-globulins (β-LG) A and B and of α-lactalbumin (α-LA) in milk were examined over a wide temperature/time range (70-150°C, 2-5400 sec). Denaturation of β-LG was best described with an apparent reaction order of 1.5 (α-LA; first order). The abrupt changes in the temperature dependence of the rate constants (β-LG at 90°C, α-LA at 80°C) were interpreted in terms of the different activation energies and entropies occurring in the two temperature ranges. By using the kinetic parameters for calculating lines of equal degrees of denaturation in a plot of log-time versus 1/absolute temperature it was possible to predict the effect of different heat treatments on the denaturation of individual proteins. 相似文献
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用Berthlot法测定酸性脲酶酶反应过程产物NH+4的浓度变化。实验表明,酸性脲酶反应是按Michaelis机理进行。其最佳反应条件是pH=4.5,反应温度60℃,反应活化能Ea=37.34kJ/mol,米氏常数Km=0.2868mmol/L,Vm=0.1744mmol/L·min. 相似文献