Physicochemical and Oxidative Changes in Sonicated Interesterified Soybean Oil

The effect of power ultrasound on physicochemical properties and oxidative stability of an interesterified soybean oil (IESBO) was investigated. IESBO was crystallized at 32 °C and sonicated for 10 s with acoustic power of 101 W. The sonicated IESBO was tested for melting behavior and chemical composition and compared to those of non sonicated IESBO to determine physical and chemical changes originated as a consequence of sonication. Application of power ultrasound affected the melting behavior of the crystallized fat and did not affect its chemical composition. Oxidation stability of the sonicated IESBO was measured using peroxide value (PV) and compared to that of non sonicated IESBO and liquid soybean oil (SBO) when stored at 25 °C for 105 days followed by storage at 40 °C for 42 days. Power ultrasound did not cause accelerated oxidation in SBO or IESBO until they were highly oxidized (PV > 10 mequiv/kg). At high levels of oxidation, non‐sonicated IESBO had significantly higher PV than sonicated IESBO, while non‐sonicated SBO had significantly lower PV than sonicated SBO.     

Composition of Rice Bran Stearin from Various Refineries Across China

In this study, we evaluated the composition of rice bran stearin (RBS) from various refineries across China. Here, we report the physicochemical parameters of RBS. The slip melting point ranged from 20.8 to 35.3 °C. The free fatty acid content (0.05–0.27 %) and peroxide value (0.34–3.70 mequiv oxygen/kg) was quite low, indicating that the RBS was of good quality. The iodine value ranged from 85.8–102.9 g/100 g, indicating a high unsaturated bond content. There was a significant difference in the unsaponifiable matter content (1.20–3.87 %) among RBS samples. The oxidative stability index (OSI) ranged from 0.56 to 5.85 h. The palmitic acid content in RBS refined by molecular distillation was significantly higher than the RBS that was refined physically and chemically. The major triacylglycerol was LLO/OLL, PLL/LPL, OLO, PLP, OOO and POO (L, linoleic acid; O, oleic acid; P, palmitic acid). RBS contained high levels of micronutrients, including total tocopherols (23.3–117.9 mg/100 g), oryzanol (0.1–2.1 %), and total sterols (682.9–1787.3 mg/100 g). Moreover, three different kinds of solid fat curves were distinguished. The results presented here are probably the first report regarding RBS on an industrial scale, meanwhile the potential utilization of RBS is discussed.     

面积深度法在库车坳陷北部盐下构造变形研究中的应用

塔里木盆地库车坳陷北部油气资源丰富,但由于受研究区地表和地下构造双重复杂特征及巨厚膏盐层的影响,其深层地震资料的成像质量与精度不理想,准确研究盐下构造形态存在较大难度。为此,基于前人的研究成果,根据最新的三维叠前深度偏移地震剖面,建立了克拉苏构造带盐下构造层的初始构造模型,并运用面积深度法分析了盐下构造层的变形特征和变形机制。结果表明:①盐下层构造的分布以克拉苏断裂为界线,断裂以北主要发育基底卷入的高角度逆冲构造,而断裂以南则主要发育滑脱构造;②克拉苏断裂以南区域滑脱面的位置介于8.01~10.23 km深度,推测该滑脱层为三叠系与下伏基底之间的不整合面;③博孜区域的滑脱距离为7.49 km,大北区域的滑脱距离为14.35 km,克深5区域的滑脱距离为12.46 km,克深1-2区域的滑脱距离则为1 6.32 km,该区盐下构造层的滑脱距离呈现出自西向东逐渐增加的趋势,表明从西向东构造变形越来越强烈。     

Low-<Emphasis Type="Italic">trans</Emphasis> Shortening and Spread Fats Produced by Electrochemical Hydrogenation

Partially hydrogenated soybean oils (90–110 IV) were prepared by electrochemical hydrogenation at a palladium/cobalt or palladium/iron cathode, moderate temperature (70–90 °C) and atmospheric pressure. The trans fatty acid (TFA) contents of 90–110 IV products ranged from 6.4 to13.8% and the amounts of stearic acid ranged from 8.8 to 15.4% (the higher stearic acid contents indicated that some reaction selectivity had been lost). The solid fat values and melting point data indicated that electrochemical hydrogenation provides a route to low-trans spreads and baking shortenings. Shortenings produced by conventional hydrogenation contain 12–25% trans fatty acids and up to 37% saturates, whereas shortening fats produced electrochemically had reduced TFA and saturate content. Electrochemical hydrogenation is also a promising route to low-trans spread and liquid margarine oils. Compared to commercial margarine/spread oils containing 8–12% TFA, the use of electrochemical hydrogenation results in about 4% TFA. Names are necessary to report factually an available data: the USDA neither guarantees nor warrants the standard of the product, and the use of the name USDA implies no approval of the product to the exclusion of others that may also be suitable.     

如何缩短大直径长拉刀的长度

文章讨论了缩短大直径拉刀长度的一般规律，以及根据各种拉刀的特点，缩短其长度的特殊措施。指出了当轮切式拉刀允许有较大的齿升量时，应尽量选取最大的Sz／t值和最大的容屑槽深；在齿升量不是主要约束条件时，可减小齿距来缩短拉刀的总长度。     

基于短地址混淆和谷歌云推送的移动僵尸网络的构建

为了提升对移动僵尸网络的预测能力和防御能力,提出了一种基于短地址混淆(USSes-Flux)和谷歌云(GCM)推送的移动僵尸网络的构建机制。设计了基于中心结构和对等网络(P2P)混合的拓扑结构的移动僵尸网络模型,给出了USSes-Flux算法,从而增强了命令与控制信道的隐秘性和强壮性。给出了该移动僵尸网络的控制模型,分析了不同僵尸节点的状态改变、命令设计和传播算法。实验环境中,研究了短地址的失效率与申请数量之间的关系,并对该移动僵尸网络与不同命令和控制信道的样本进行静态分析、动态分析和电量测试。结果表明:该移动僵尸网络具有较强的隐秘性、强壮性和低消耗。     

Physicochemical and Rheological Characterization of Roll-in Shortenings

The composition and physical properties of roll‐in shortenings, commonly rich in trans and saturated fatty acids, were investigated and compared to other specialty fats, to provide insights into the physico‐chemical origins of their functionality. Triacylglycerols and fatty acid composition, polymorphic and melting behavior, solid fat content and large deformation rheological properties were determined. Roll‐in shortenings contained higher amounts of trisaturated and unsaturated triacylglycerols (12–27 %; 47–62 %) than other shortenings (9–11 %; 6–44 %). However, all exhibited high levels of saturates and trans fatty acids and similar crystal characteristics: β′ or mixed β′ and β, irrespective of their end use. Roll‐in shortenings had comparable melting peaks (42–52 °C) but sharper melting endotherms with higher enthalpies (38.6–43.3 J/g) than other bakery fats (18.7–25.4 J/g). This was in accordance with their well‐defined short spacings, indicative of smaller crystallites with more‐ordered packing. Solid fat profiles of roll‐in shortenings were akin to all purpose and cake interesterified shortenings, but not to all‐purpose and icing shortenings which displayed substantial melting as temperature rises. Differences in large deformation rheology (yield stress: σ^*, apparent Young modulus: E_app, yield value: C) were marginal and inconsistent with their solid fat content. Roll‐in shortenings exhibited E_app, σ and C in the order of 1–2 × 10⁶, 4–7 × 10⁴, and 7–29 × 10⁴ Pa, respectively. Particularly, the σ*and C, previously established as major parameters to specify the functionality of roll‐in shortenings, were not significantly different (p > 0.05). Overall, roll‐in shortening differed from other samples in regard to molecular makeup but not greatly in their physical parameters, suggesting that triacylglycerol composition has important implications on their functionality.     

Characteristics of palm mid-fractions produced from different fractionation paths and their potential usages

Three palm mid-fraction (PMF) groups produced from different fractionation paths were analyzed in terms of the fat, triacylglycerol and sn-2 fatty acid compositions, thermal properties (melting and crystallization behaviors, and solid fat contents (SFCs)), micronutrient levels and oxidative stability indexes (OSIs) to achieve their sufficient utilization. PMF-A (iodine value (IV), 48.4 g/100 g) fractionated from palm olein contained 43.8% 1,3-dipalmitoyl-2-oleoyl-glycerol (POP) and 16.7% 1-palmitoyl-2,3-dioleoyl-glycerol, showing soften properties (slip melting point (SMP), 27.6°C; SFC at 30°C, 2.2%) at hot weather. PMF-B (IV, 42.3 g/100g) obtained from palm stearin showed similar fat and triacylglycerol compositions as PMF-A, but the high 1,2,3-tripalmitoyl-glycerol level (6.2%) improves its thermal behaviors (SMP, 34.9°C; SFC at 30°C, 13.8%). The SFC profiles of PMF-A and PMF-B were comparable to those found in frozen and puff margarine shortenings. Furthermore, both of the PMF groups exhibited excellent OSIs (13.2 and 11.2 h, respectively) because of their high micronutrient levels (especially γ-tocopherol and campesterol). In general, γ-tocopherol and campesterol contribute to preventing lipids from oxidation under frying conditions. Therefore, PMF-A and PMF-B are recommended for manufacturing margarine shortenings and frying fasts. PMF-C (IV, 33.0 g/100g) produced from the additional fractionation of PMF-A or PMF-B contained the highest POP percentage (67.1%) and showed heat-resistant property (SMP, 31.8°C; SFC at 30°C, 22.4%). Its steep SFC profile was superior to that of cocoa butter, suggesting the fat is preferred in producing hard chocolate fats.     

焙烤食品乳化剂的应用和进展

概述了焙烤食品中各种乳化剂的功效、种类和ＨＬＢ值,讨论了乳化剂在液体起酥油和高浓度果糖浆的熔烤食品配方的应用。