Determination of Protein Levels in Nigerian Grains Using 14 MeV Neutron Activation Analysis

Fast (14 MeV) neutrons have been successfully used in investigating the protein content of different food grains (Soya Beans, Sorghum, Maize and Beans) locally grown and consumed in Nigeria. Protein was estimated via nitrogen using the ¹⁴N(n, 2n)¹³N reaction. Quantification of nitrogen was achieved through a γ-γ coincidence counting of 511 keV positron emissions from the decaying ¹³N. The implication of the use of the emitted annihilation positrons, the interference introduced in the analytical energy spectra from other activated target nuclides present in the sample, as well as possible proton “knock on” reactions anticipated from cellulose in grain matrix were assessed, and their contributions to the 511 keV gamma energy resolved. For comparative purposes, replicates of samples analyzed through Fast Neutron Activation Analysis (FNAA) were investigated using the Kjeldahl method. The samples were carried through the Kjeldahl process of pre-digestion (with appropriate catalysts), digestion and titration. The results obtained through the Kjeldahl process were found to be in good agreement with those obtained using FNAA although slightly lower. Protein content (%) of Nigerian grains analyzed varied from a low 8.75 ± 2.96 for sorghum to 35.93 ± 0.31 for soya beans.     

水分胁迫对小豆抗氧化酶活性及小豆叶片解剖结构的影响

用不同浓度PEG处理小豆幼苗,生理生化方法测定MDA含量、可溶性蛋白含量及各种酶活性变化.叶片制作石蜡切片,光学显微镜观察结构.结果显示在整个水分胁迫过程中,随着PEG浓度的增加,小豆叶片MDA含量总体表现为先增加后减少的趋势,可溶性蛋白含量变化表现为先增加后降低再增加的趋势.PEG浓度较低时,小豆SOD活性下降,随着浓度的增加,SOD活性又上升.POD与CAT活性变化趋势一致.经PEG处理后,3种栽培小豆叶片结构变化均表现为叶片失水,萎焉,表皮细胞萎缩或者破碎,栅栏组织细胞变短,形状变不规则,海绵组织变小,细胞破碎,细胞结构破坏,细胞间隙变小.     

王维《相思》“春”“秋”二字小考

王维《相思》是“秋来发几枝”还是“春来发几枝”历来颇有争议。本文试图通过这首诗版本演变过程的探究,说明应该是“秋来发几枝”。     

Effect of irradiation on anti-nutrients (total phenolics, tannins and phytate) in Brazilian beans

The Brazilian bean varieties Phaseolus vulgaris L. var. Carioca and Vigna unguiculata (L.) Walp var. Macaçar were irradiated with doses of 0.5, 1.0, 2.5, 5.0 and 10 kGy and subsequently stored at ambient temperature for 6 months. The anti-nutrients phenolic compounds, tannins and phytate were determined to be 0.48 mg g⁻¹ dry basis, 1.8 mg g⁻¹ dry basis and 13.5 μmol g⁻¹ dry basis in the raw non-irradiated Carioca beans and 0.30 mg g⁻¹ dry basis, 0.42 mg g⁻¹ dry basis and 7.5 μmol g⁻¹ dry basis in the raw non-irradiated Macaçar beans. After soaking and cooking a higher content of phenolic compounds and a lower phytate content was observed in both bean varieties. Tannin content was not affected by soaking and cooking of Carioca beans, but higher after soaking and cooking of Macaçar beans. Using radiation doses relevant for food did not effect the content of the anti-nutrients under investigation in both bean varieties.     

Effect of gamma irradiation on the microbiological quality and on the functional properties of proteins in dry red kidney beans (Phaseolus vulgaris)

Gamma-irradiation was found to affect the physicochemical properties of dry red kidney beans. The highest dose used (8 kGy) significantly (P0.05) modified the extent of deamidation, the number of sulfhydryl groups, as well as the solubility and the hydrophobicity of the protein. Deamidation, protein solubility and hydrophobicity all increased with the irradiation dose while the number of sulfhydryl groups was reduced by the treatment. Furthermore, irradiation also affected the outgrowth of natural filamentous fungi contaminants present on the dry beans. A dose of 1.5 kGy reduced the number of filamentous fungi by 2 log cycles immediately after treatment. However, the highest dose used (3 kGy) did not eliminate the filamentous fungi completely. Moreover, the filamentous fungi population was a lot less diversified on the irradiated samples. Species of Aspergillus sp. and Penicillium sp. were more abundant on the unirradiated beans while the beans irradiated at 3 kGy contained were predominantly infected by species of Rhizopus sp. , Cladosporium sp. and Alternaria sp.     

分光光度法测定豆类及其粗蛋白质中的色氨酸

建立一种快速，准确测定豆类试样及其粗蛋白质中色氨酸含量的分光光度法，讨论最佳试验条件及试剂用量，反应产物在４１０ｎｍ处具有最大吸收波长ε＝１．１０３×１０~４Ｌ／ｍｏｌ·ｃｍ。回收率９３．５０％－１１０．０％，相对标准偏差小于２．６１％。     

FTIR光谱法定性鉴别有毒豆角

用红外光谱法对有毒和无毒豆角进行了分析，找到了一种操作简便、经济实用的定性鉴别有毒豆角的方法。     

悬浮液进样火焰原子吸收光谱法测定豆米类粮食中镁

将样品磨细配制成悬浮液,并对悬浮剂的选择及化学干扰的消除进行了考查。为消除化学干扰，取适量悬浮液，加入La3+溶液制成试液。将试液喷入空气-乙炔火焰，以空白溶液为参比，用工作曲线法进行测定。测定结果与灰化法一致，相对误差小于±1.3％。方法简便、快速、准确。     

基于互联网的工业现场温度数据动态采集系统开发

目前,互联网技术的成熟促进了工业现场控制领域的深刻变革．针对多数工业现场冷热交加、工作条件苛刻的实际情况,提出了基于互联网的现场温度数据采集系统的解决方案．在给出数据采集系统通信原理的基础上,通过面向组件的Java编程语言(JSP／Servlets)和Visual C 6．0编程技术,实现了数据采集系统的信息通信．根据用户需求,实现了基于国际互联网的数据采集系统信息显示的动态刷新、浏览、查询和数据分析、备份以及数据采集控制等功能．该系统在大连理工大学计算机控制研究所S319．dlut．edu．cn服务器上试验,通过并联15个DUT3000模块对现场温度数据的21万条采集试验,验证了该系统的实效性和便捷性．     

Effect of gamma irradiation on the thiamine, riboflavin and vitamin B6 content in two varieties of Brazilian beans

The effect of ⁶⁰Co gamma rays on the content of several B-vitamins in two varieties of Brazilian beans has been studied. Carioca (Phaseolus vulgaris L. var. Carioca) and Macaçar beans (Vigna unguiculata L. Walp, var. Macaçar) were irradiated at doses of 0, 0.5, 1.0, 2.5, 5.0 and 10 kGy, and subsequently stored at ambient temperature for 6 months. The content of vitamin B₁, B₂ and B₆ was analysed by HPLC. In addition, the optimum cooking time was established for each dose and bean variety. A taste panel evaluated sensory properties. Only slight changes were measured for thiamine and riboflavin, whereas a dose-dependent decrease was noted for pyridoxine, which, however, was significant only at the highest doses of 5 and 10 kGy. Cooking time was considerably reduced with increasing radiation dose, but accompanied by a loss of the sensory quality. However, at the disinfestation dose up to 1 kGy, acceptable ratings were obtained for the sensory evaluation. In conclusion, for insect disinfestation of Brazilian beans radiation processing is a promising technology.