菜籽油磷脂酶C脱胶与水化脱胶条件优化及效果对比研究

以菜籽毛油为原料,分别利用二次回归正交实验对菜籽毛油磷脂酶C(PLC)脱胶工艺和常规水化脱胶工艺进行优化,按照国标要求,对两种不同脱胶方式生产的菜籽油的磷脂含量、水分、过氧化值等基本指标进行检测,并对指标结果进行对比。确定了PLC用于菜籽毛油脱胶的最优工艺参数为p H5.4、酶添加量10μL/kg、酶解温度42℃,经PLC脱胶后菜籽油磷脂含量为7.45mg/kg;水化脱胶最优工艺参数为作用时间4.8h、操作温度86℃、加水量为毛油磷脂含量的3.2倍,经水化脱胶后菜籽油磷脂含量为76.32mg/kg。且酶法脱胶油整体上比水化脱胶油品质更好,酶法脱胶油经常规精炼后可达到国家一级油标准,该研究可为菜籽油酶法脱胶工业生产提供一定的理论参考。      

滚筒复烤方式下不同尺寸烟片的干燥与收缩特性对比分析

以贵州C3F、河南C3F、河南B3F 3种烟叶为原料,利用实验室批式滚筒复合传热干燥装置进行试验。结果表明:滚筒复烤方式下,同种烟叶烟片尺寸规格的变化对其干燥速率和复烤后温度无明显影响。网孔12.70 mm以上的筛分烟片,烤后225~625 mm 2的叶片比例增加明显;网孔6.35~12.70 mm的筛分烟片,烤后36~225 mm 2的叶片比例增加明显。复烤后烟片总体尺寸分布在225~625 mm 2和36~225 mm 2面积区间呈集中趋势。烟片尺寸规格对滚筒复烤皱缩率影响显著,3种烟叶原料烤后烟片的皱缩率均随尺寸规格的增大呈明显上升趋势。     

滚筒复烤方式下不同尺寸烟片的干燥与收缩特性对比分析

施用于建筑外檐的装修构件,不仅具有避风、遮阳、调节建筑室内温度的功能,也是建筑外观形象的重要组成部分。虽然现存早期建筑遗构中保存的此类构件很少, 为系统深入研究这些构件的形制和用法带来了一些困难, 但两宋的建筑绘画中保存了相当多当时外檐装修的图像资料,能够补充实物资料的不足。本文即通过对这些图像资料的考察与分析,结合《营造法式》等文献的记载,讨论宋代建筑中常设于建筑外檐,起避风遮阳作用的擗帘竿、 避风?、障日?、引檐四类构件的形制与用法,以及由此产生的丰富多样的建筑外观效果。     

不同菌种发酵制备蚕豆酱的研究

本试验研究米曲霉、黑曲霉、黑根霉、高大毛霉4种不同单一菌种分别发酵制得的蚕豆酱中蛋白酶、淀粉酶活力及主要成分、酱色OD420nm值等指标在不同发酵时期的变化,并对发酵42d的蚕豆酱进行感官评价。结果表明,米曲霉的中性及碱性蛋白酶活力较其他三种菌强,分别高达546.84U和188.79U。米曲霉发酵的蚕豆酱氨基酸态氮含量最高,可达1.381 g/100g,根霉、黑曲霉次之,毛霉最少。米曲霉和黑曲霉制得酱的颜色深,酱色OD420nm值高,另两种霉制得酱的颜色较浅。米曲霉发酵制得蚕豆酱在色泽、气味和口感上都达到一级标准,是制作蚕豆酱的良好发酵菌种。     

基于稳健性设计的筛分加料工序质量评价和参数优化

为探明各影响因素对工序加工质量的影响,采用田口方法--稳健性设计对筛分加料工序进行了较为系统的质量评价与参数优化。结果表明:1)热风温度对加料后叶片平均含水率和温度的影响均为最大,筒体转速对加料后叶片平均含水率和温度的影响均为最小;2)物料流量对加料后叶片含水率和温度的波动影响均为最大,筒体转速对含水率的波动影响最小,蒸汽压力对温度的波动影响最小;3)为减小加料后叶片含水率和温度的波动,以质量损失最小化为原则,各因素水平最适组合为:热风温度75℃、蒸汽压力0.35MPa、物料流量4000kg/h、筒体转速13.5r/min;4)综合各因素对加料后叶片含水率和温度的影响大小,可将热风温度和物料流量视为重要因素,蒸汽压力视为调节因素,筒体转速视为次要因素。      

精梳锡林与顶梳的优化配置

通过对2种比较典型的精梳锡林和顶梳的使用试验，分析得出锡林的齿顶锋利度、齿间距、齿面圆心角度；顶梳的位置前移；锡林与顶梳齿面的粗糙度与精梳棉每中的棉结杂质粒数和短绒率高低的关系。     

Comparison of the phytohaemagglutinin from red kidney bean (Phaseolus vulgaris) purified by different affinity chromatography

Affinity chromatography (AC) on Affi-Gel blue gel column and thyroglobulin (Tg)-Sepharose 4B column, respectively, were compared for their efficiency in purifying phytohaemagglutinin (PHA) from red kidney beans (Phaseolus vulgaris). Considering the purity and haemagglutinating activity of the obtained samples, Affi-Gel blue gel exhibited less affinity for PHA than Tg-Sepharose matrix. Affi-Gel blue purified sample showed multiple bands in SDS-PAGE gel, which further confirmed that Affi-Gel blue bound non-PHA proteins as well as PHA. PHA purified by one-step Tg-Sepharose column gave significantly (p < 0.05) higher purity (0.75 ± 0.13 mg PHA/mg lyophilized powder) than the sample purified by two-step (Affi-Gel blue first and then Tg-Sepharose) purification (0.62 ± 0.20 mg PHA/mg lyophilized powder). Circular dichroism (CD) spectra showed that the sample purified by one-step Tg-Sepharose column had similar secondary structures with the sample purified by two-step purification. Thus, one-step Tg-Sepharose purification was effective and time-saving for the preparation of PHA and a promising substitute for the two-step purification method.     

东北黄豆和黑豆脂肪酸成分的比较研究

采用索氏提取法提取东北黄豆和黑豆中的脂肪酸成分并进行甲酯化处理,以气相色谱-质谱法对其进行分析,对其脂肪酸组成和含量进行了比较。结果表明:黄豆和黑豆中均有15种脂肪酸,两者主要成分均为亚油酸,分别占脂肪酸总量的63.21%和61.66%。用高效液相色谱法对亚油酸进行了定量分析。色谱柱为KromasilC18;流动相:异丙醇:乙腈=35:65;柱温:25℃;检测波长:205nm;回归方程为y=1×106x+0.7×106,r=0.9999,变异系数小于1.35%,回收率为98.8%～109.1%。     

Oxidative effects in uninfected tissue in leaves of French bean (Phaseolus vulgaris) containing soft rots caused by Botrytis cinerea

Several markers of oxidative processes have been measured in leaves of Phaseolus vulgaris infected with Botrytis cinerea, with the specific objective of investigating changes induced by this necrotrophic pathogen in tissue remote from the lesion. There was a progressive decrease with time in the contents of ascorbic acid (AA) in apparently healthy tissues from infected plants and non‐inoculated plants grown under identical high‐humidity conditions (abiotically stressed controls), and for periods >48 h this decrease was greater in the infected plants. This decline in AA content was accompanied by an elevation in the intensity of the electron paramagnetic resonance (EPR) signal from adducts of the spin trap α‐(4‐pyridyl‐1‐oxide)‐N‐t‐butylnitrone (POBN), a destabilisation of the (monodehydro) ascorbate radical (Asc^·) signal in the presence of POBN, and an increase in the ratio of Asc^· to AA in samples studied in the absence of the spin trap. These results are consistent with a shift in redox status to more oxidising conditions in apparently healthy tissue of infected plants and indicate the prevalence of chemical processes that are distinctly different from those in uninfected plants. However, no differences in lipid peroxidation products or the single‐peak free radical and Fe(III) (g = 4.27) EPR signals were observed between these tissues distant from the lesions and those from abiotically stressed controls. In addition, the pathogen‐derived sesquiterpene toxin botrydial and a second Mn(II) EPR signal, both of which are associated with Botrytis infection, were not detected in these ‘apparently healthy’ tissues. Copyright © 2003 Society of Chemical Industry     

蛋白酶水解豆渣制备大豆肽的研究

以大豆豆渣为原料,分别采用木瓜蛋白酶、碱性蛋白酶、中性蛋白酶对大豆豆渣进行水解制备大豆肽.研究了3种蛋白酶在不同温度、pH值、水解时间、酶浓度下水解大豆豆渣的最适酶反应条件,以及水解产物对酸豆乳发酵的影响.结果得出,实验豆渣蛋白质含量为10.4 g/(100 g);木瓜蛋白酶的最适水解条件是底物质量分数5％,酶浓度20 000 U/g,水解温度为50℃,pH7,水解6h,最大水解度可达87.31％;碱性蛋白酶的最适水解条件是底物质量分数5％,酶浓度15 000 U/g,水解温度为55℃,pH9,水解3h,最大水解度可达91.23％;中性蛋白酶的最适水解条件是底物质量分数5％,酶浓度15 000 U/g,水解温度为45℃,pH7,水解8h后达到最大水解度,最大水解度可达81.42％.     

Structure of faba bean, black bean and pinto bean starches at different levels of granule organization and their physicochemical properties

The structure and physicochemical properties of pulse starches isolated from different cultivars of faba bean (FB), black bean (BB) and pinto bean (PB) were examined. FB starches exhibited numerous cracked granules, whereas the surface of PB and BB starches showed no evidence of cracks or indentations. Apparent amylose, phosphorus and bound lipid contents ranged from 25.8 to 33.6%, 0.004 to 0.009% and 0.13 to 0.15%, respectively. Variations in the above parameters among cultivars of FB and BB were marginal, but significant (P < 0.05) among cultivars of PB. All starches exhibited a ‘C’ type X-ray pattern. The amount of B-type unit cells ranged from 20.6 to 25.0% (FB), 15.4 to 17.7% (BB) and 7.9 to 17.3% (PB). Relative crystallinity ranged from 20.3 to 21.9% (FB), 20.4 to 21.3% (BB) and 21.3 to 23.1% (PB). Molecular order near the granule surface followed the order: BB ~ PB > FB. Variations in molecular order among cultivars of FB, BB and PB were marginal. Differences in amylopectin chain length distribution among FB, BB and PB starches and among cultivars were marginal. The extent of interaction of amylopectin double helical associations within the crystalline lamella followed the order: BB ~ PB > FB. Amylose leaching (AML) in the temperature range 60–90 °C, gelatinization temperatures and enthalpy of gelatinization followed the order: FB > BB ~ PB, FB > PB > BB, BB ~ PB > FB and BB ~ PB > FB, respectively. Variations in AML among cultivars were marginal in FB, but significant (P < 0.05) in BB and PB starches. Swelling factor (SF) in the temperature range 60 to 85 °C and at 90 °C followed the order: FB > BB ~ PB and BB ~ PB > FB, respectively. Differences in SF among cultivars of FB and BB starches were more significant (P < 0.05) at temperatures below 80 °C, whereas, in PB starches, differences among cultivars were more significant (P < 0.05) at temperatures above 80 °C. Variations in peak viscosity, viscosity breakdown and set-back were marginal among FB cultivars, but were significant (P < 0.05) among BB and PB (PB > BB) cultivars. FB starches were hydrolyzed by 2.2 N HCl at a faster rate than BB and PB starches (BB > PB). The amounts of rapidly digestible starch (RDS), slowly digestible starch (SDS), resistant starch (RS), hydrolysis index (HI) and expected glycemic index (eGI) followed the order: FB > BB ~ PB, FB > BB ~ PB, BB ~ PB > FB, FB > BB > PB and FB > BB > PB, respectively. Variations in RDS, SDS, RS, HI and eGI among cultivars followed the order: PB > BB > FB. The in vitro digestibility studies showed that PB and BB starches may be more effective than FB starches in controlling blood glucose levels.