Increasing oxidative stability in corn oils through extraction of γ-oryzanol from heat treated rice bran

Corn oil was mixed with heated rice bran with different extraction periods and ratios of rice bran to corn oil to extract γ-oryzanol from rice bran. Selected corn oils based on the content of γ-oryzanol were heated at 180 °C for 100 min or 60 °C for 16 days, and oxidative stability was evaluated. Corn oils recovered from the mixture of rice bran showed higher oxidative stability at both 60 and 180 °C treatment compared to control corn oils. At 180 °C, corn oils of a 1:5 ratio of rice bran to corn oil (w/w) showed higher oxidative stability than did those of 1:3 and 1:7 (w/w), whereas at 60 °C, corn oils of 1:7 (w/w) showed higher oxidative stability than did others. γ-Oryzanol can be extracted through a corn-oil mixture at 80–90 mg/100 g oil, which is about 4.0% recovery of 2244 mg/100 g crude rice-bran oil. Oxidative stability of corn oils increased significantly, partly because of the extraction of γ-oryzanol under current experimental conditions.     

Digital imaging as a tool to study the structure of porous baked foods

Processing of images captured by a digital camera showed to be useful in studying the microstructure (porosity characteristics and fractal dimension) of leavened baked products. Five different samples were baked including a control and 4 other samples in which wheat flour was partially replaced with other plant flours. Pasting temperature (°C) ranged from 72.94 to 76.25 with chickpea flour showing the highest value. The sample containing amaranth flour presented high porosity (8.23%) with high number of large pores. Whereas, the number of pores was highest for teff flour with 209 pores. This is an indication of weak potential of amaranth flour in stabilizing gas cells. The fractal dimension ranged from 1.644 to 1.683, where amaranth flour showed the lowest fractal dimension. The pore characteristics evaluation, pore size distribution, number of pores, mean area and largest area of pores were influenced when gluten was reduced. Processed images proved that coalescence can be a cause of large pore development when gluten is partially removed.     

Evaluation of yield,stability and adaptability of national winter rapeseed regional trials in the upper Yangtze River region in 2017-2018

Rapeseed variety needs to be tested by regional trial in multiple sites for many years before being applied in market in China. Performants of rapeseed were affected by the interaction of sites and varieties. Evaluation of regional trials is very important for guiding rapeseed breeding. GGE (genotype main effects and genotype ​× ​environment interaction) biplot was used to evaluate yield, stability, adaptability, representativeness and discrimination of national winter rapeseed trials in the upper reaches of Yangtze River in 2017-2018. Results showed that the main effects of genotype (G), environment (E) and genotype ​× ​environment interaction (G × E) were significant (P ​< ​0.01) for yield. Among them, E accounted for 46.95% total variation on average, G and G × E accounted for 19.34% and 33.71% respectively. Eight varieties were found with high-yield, excellent stability and adaptability, including ‘Yiyou 29’, ‘Xiwang 920’, ‘Liyouza 108’, ‘Nanyou 546’, ‘Dadi 195’, ‘Jiayou 1’, ‘Huayouza 28’ and ‘Yuhua 2’. Test sites included Nanchong, Mianyang, Wanzhou, Shuangliu and Chengdu in Sichuan Province and Zunyi together with Guiyang in Guizhou Province were selected for their excellent representativeness and discrimination. These results would provide theoretical basis for rapeseed breeding.     

高蛋白饮用型酸乳体系中微粒化乳清蛋白和物理改性淀粉对稳定性的影响

将微粒化乳清蛋白和2 种物理改性淀粉（大麦物理改性淀粉和大米物理改性淀粉）作为酸乳清洁标签的高蛋白饮用型酸乳体系，研究微粒化乳清蛋白（0.5 g/100 mL）和2 种物理改性淀粉（0.5、1.0 g/100 mL）对酸乳体系的影响。结果表明：5 种不同酸乳体系均具有较好的持水性和较高的黏度，其中，大麦物理改性淀粉添加量为1.0 g/100 mL的酸乳体系持水力最高，达70.20%，该体系黏度也最高，为4 422 mPa·s；粒径分布和流变学特性分析结果均显示，大麦物理改性淀粉对酸乳体系的稳定性有较好的维持作用；微粒化乳清蛋白酸乳体系指标值略低于物理改性淀粉体系，但是差异并不明显。     

接装纸涂胶量对卷烟滤嘴通风率的影响

为使接装纸透气度及滤嘴通风率在指标范围内保持稳定,采用单因素试验法,研究接装纸涂胶量对接装纸透气度及滤嘴通风率的影响,以及接装纸涂胶量随接装机运转速度和接装纸包角的变化关系。结果表明,1接装纸涂胶量对接装纸透气度及滤嘴通风率的影响显著;2接装纸涂胶量随接装机运转速度的提高而减少;3接装纸涂胶量随接装纸包角的增大而增加。并建立了接装纸涂胶量与接装机运转速度和接装纸涂胶量与接装纸包角之间的函数关系,经过分析计算得到了接装纸包角与接装机运行速度的数学模型。当接装机运转速度发生变化时,该模型可通过调节接装纸包角使接装纸涂胶量保持稳定,进而使接装纸透气度及滤嘴通风率保持稳定。     

长白山芳香植物精油膏的研制

将黄花蒿等11种长白山特有药用草本植物精油与化妆品基质配制成植物精油膏,并对其进行了稳定性及安全性检测。结果表明,精油膏在10 000 r/min下离心10 min,在-5、25、40℃等不同温度下放置24 h并循环3次,均表现出牢固的稳定性;甲醇含量为0.081%;砷、汞、铅限定物质含量分别是0.011 81、0.000 85、0.035 50 mg/kg,均符合国家标准。利用长白山特有草本植物精油制得的芳香植物精油膏是一个安全、有效、无毒的绿色产品,具有良好的开发前景。     

Dynamics of Aggregate Stability Influenced by Soil Management and Crop Residues

Abstract

The type of tillage and crop systems used can either degrade or cause a recovery of the structure of agricultural soils. The objective of this study was to determine the structural stability of the soil using mean weight diameter (MWD) of soil aggregates in three different periods of a succession of crops consisting of beans/cover plants/maize under no tillage (NT) and conventional tillage (CT) management systems. Soils were sampled at 0‐ to 5‐cm and 5‐ to 15‐cm depths in three periods (P1, P2, P3): 1) November 2002 (spring/summer), 2) April 2003 (beginning of autumn), and 3) December 2003 (end of spring/beginning of summer). Aggregate stability was determined by wet sieving. The effects of the tillage systems, vegetal residues, and sampling depths on the structural stability of the aggregates were assessed and then related to organic matter (OM) contents. Aggregate stability showed temporal variation as a function of OM contents and sampling period. No tillage led to high MWD values in all study periods. The lowest MWD values and OM contents were observed 4 months after the management of the residues of cover plants. This finding is consistent with the fact that at the time of the samplings, most of the OM had already mineralized. The residues of sunn‐hemp, millet, and spontaneous vegetation showed similar effects on soil aggregate stability.     

淡色生赤壳菌YLZ42发酵液稳定性及活性物质的初步研究

从广西玉林土壤中分离获得一株淡色生赤壳菌YLZ42,其发酵产物对蜡样芽孢杆菌等具有良好的抑制作用。以蜡样芽孢杆菌为指示菌对该菌株发酵产物的活性特性进行了研究,结果表明该菌发酵液的抑菌活性在40~60℃温度范围内比较稳定,60℃加热1 h,活性损失小于7%;在p H 2~7范围内抑菌活性稳定,p H大于7时,活性损失较大,在p H 8条件下处理12 h活性损失已达到64%;发酵液适宜在酸性条件下保存,p H 4的发酵液放置15 d后活性损失小于5%;活性物质对紫外线不敏感,经紫外照射24 h后抑菌活性基本不变。然后采用萃取、薄层制备、HPLC制备等提取分离方法得到了抑菌活性物质的纯品,分子量为513,与相关文献中报道的活性代谢产物的分子量均不同。     

基于综合法的重力坝整体稳定性安全度分析

采用ABAQUS有限元软件,利用先降强后超载的综合法、依据塑性应变能和屈服区贯通两种突变性判据对重力坝进行整体稳定性分析。分析表明：采用综合法时,初始强度折减系数为1.3分析重力坝整体稳定性比较适合;初始强度折减系数较大,综合安全系数也较大。     

Competitive Strategies and Growth of Neighbouring Bromus valdivianus Phil. and Lolium perenne L. Plants Under Water Restriction

Often perennial pastures have to tolerate soil water restriction during summer, which can affect the relative abundance of the most desired species. In the south of Chile, Bromus valdivianus and Lolium perenne are preferred species. The competitiveness of B. valdivianus and L. perenne was evaluated when sown in pots in a glasshouse as monocultures or a mix (50/50 %) with restricted water availability. The water restriction treatments were as follows: 80–85 % field capacity (FC), 45–50 % FC and 20–25 % FC, maintained for 1196 growing degree days. For both species, dry matter (DM) accumulated per plant and per pot decreased similarly with increasing water restriction, but at tiller level, resource allocation differed, for B. valdivianus root growth was accentuated over aerial development, but this was less so for L. perenne. The foliage mass per tiller for B. valdivianus decreased relatively more than that for L. perenne with increasing water restriction. As monocultures, B. valdivianus produced larger tillers than L. perenne, such that B. valdivianus tillers had 2.2 times greater lamina mass, 3.6 times more leaf area and 2.5 times greater root mass than those of L. perenne. However, L. perenne produced a larger number of smaller tillers that enabled foliage, root and total mass at plant level, to be similar to that of B. valdivianus. Within the mixed pasture, L. perenne tiller density increased compared with when grown as a monoculture, but not for B. valdivianus. The results of the study suggested that L. perenne and B. valdivianus have differences in growth strategies that allow them to survive under environmental stress and competition. Competitiveness increased for L. perenne aboveground without water restriction and that for B. valdivianus increased belowground as water restriction was increased.