牡丹籽仁压榨油和浸提油联合生产工艺研究

为了提高牡丹籽仁油的提取率,得到高品质的油脂以及低残油且未变性的饼粕,本文研究压榨和浸提两种方法联合生产牡丹籽仁油的工艺,并分别对两种工艺进行优化。结果表明:液压压榨最优工艺为物料粒度40目、物料含水率为5%、压榨次数3次、压榨时间20 min、压榨温度60℃、压榨压力55 MPa;溶剂浸提最优工艺为浸提次数3次、料液比1∶10、浸提温度50℃、浸提时间120 min。在两种工艺综合提取下,牡丹籽仁油总得率高达98.86%。其中压榨牡丹籽仁油不饱和脂肪酸高达91.36%,浸提牡丹籽仁油不饱和脂肪酸高达90.64%,均具有较高的营养价值,因此有望开发成为一种高营养保健食用油脂。     

Y-doped BaCeO3−δ nanopowders as proton-conducting electrolyte materials for ethane fuel cells to co-generate ethylene and electricity

Y-doped BaCeO_3−δ (BCY) powders synthesized using a combustion method are pure perovskite phases. The particles are uniform spherical particles about 50 nm. The properties of BCY proton-conducting electrolyte sintered at different temperatures from pressed nanopowders were systematically investigated. Dense BCY pellets are obtained at temperatures higher than 1400 °C for 10 h. Electrical conductivity and resistance to CO₂ atmosphere each increase with sintering temperature. Fuel cells having about 0.8 mm thick BCY electrolyte and Pt electrodes co-produce 151 mW cm⁻² electrical power and value-added ethylene with selectivity over 90% at ethane conversion about 35% at 700 °C.     

青春双歧杆菌耐氧驯化及培养条件的响应面法优化

对一株青春双歧杆菌进行耐氧驯化,通过有氧、无氧交替驯化法对出发菌株进行耐氧驯化,得到耐氧能力较强的青春双歧杆菌菌株,在有氧静止培养条件下活菌数可达到4.31×1011cfu/mL。对该耐氧菌株通过响应面法进行培养条件优化,确定培养耐氧青春双歧杆菌的最佳条件:接种量5%,玉米糖化液浓度12.1°Bx,初始pH6.48,培养温度37℃,发酵时间24h。在此条件下菌液最大OD值为1.819,此条件下培养的活菌数为3.05×1012cfu/mL。     

Effect of Ba doping on performance of LST as anode in solid oxide fuel cells

The level of barium doping in lanthanum strontium titanate (La_0.4Sr_0.6−xBa_xTiO₃, 0 ≤ x ≤ 0.2; LST, x = 0; LSBT, x > 0), prepared by solid state synthesis, affects its performance as anode in solid oxide fuel cells (SOFCs). Cell structures of LST and all LSBT were similar. The oxidation state of Ti in all compounds was reduced by a comparable amount when LST or LSBT was heated under reducing conditions to form La_0.4Sr_0.6−xBa_xTi_0.59⁴⁺Ti_0.41³⁺O_2.97. All fuel cells using LST or LSBT had high activity for conversion of hydrogen or methane, and the activity increased with the level of substitution by Ba. In addition, performance was enhanced when H₂S was present in either CH₄ or H₂ fuel. There was good contact between YSZ electrolyte and each LSBT or LSB anode.     

关于模块余热炉模块产品系列化的几点归纳

立式模块余热锅炉近些年来市场一直较好,而制造过程中因为同一种类的炉型结构相近,根据我公司已经生产的实际情况,对可以进行简化设计程序,逐渐成为系列化的路型进行大概的归纳。     

腌制风干过程中卵形鲳鲹鱼肉性质、蛋白质氧化及游离氨基酸的变化

为探究卵形鲳鲹在腌制风干过程中蛋白质氧化及游离氨基酸的变化规律,对卵形鲳鲹鱼肉含水率、盐含量、质构特性、肌原纤维蛋白二级结构、羰基含量、巯基含量、蛋白质水解指数、十二烷基硫酸钠-聚丙烯酰胺凝胶电泳图谱和游离氨基酸等进行测定分析。结果表明：在腌制风干过程中,卵形鲳鲹鱼肉的盐含量整体呈上升趋势,含水率下降,硬度增加,而弹性则先上升后下降。鱼肉蛋白质在加工过程中发生氧化反应,羰基含量明显增加,而巯基含量明显下降,同时肌原纤维蛋白二级结构中α-螺旋含量减少,而无规卷曲含量增加。在加工过程中肌球蛋白重链条带和肌动蛋白发生明显变化,肌球蛋白重链条带变浅并在风干后消失,表明肌原纤维蛋白发生水解;鱼肉的蛋白质水解指数增加,非蛋白氮含量在腌制后下降而在风干过程中增加;游离氨基酸总量在干制1 d后达到最高,鲜味氨基酸和苦味氨基酸含量整体呈上升趋势。本研究可为腌制水产品加工过程中品质控制提供一定理论参考。     

叶黄素微胶囊化研究

以反式叶黄素晶体为芯材,辛烯基琥珀酸酯化淀粉和蔗糖为壁材,通过乳化、均质、喷雾干燥等工艺,制备叶黄素微胶囊。通过单因素试验和正交试验确定叶黄素微胶囊化最优的工艺条件为蔗糖占总壁材质量为10%、壁材质量浓度0.15g/mL、芯壁材质量比1:15、乳化剂添加量为总壁材质量的0.6%、胶体磨均质两次、进料速度400mL/h、进风温度160℃、出风温度80℃,所得产品微胶囊效率和产率分别为92.35%和90.27%,且品质良好。     

Bacteriocins as food preservatives: Challenges and emerging horizons

ABSTRACT

The increasing demand for fresh-like food products and the potential health hazards of chemically preserved and processed food products have led to the advent of alternative technologies for the preservation and maintenance of the freshness of the food products. One such preservation strategy is the usage of bacteriocins or bacteriocins producing starter cultures for the preservation of the intended food matrixes. Bacteriocins are ribosomally synthesized smaller polypeptide molecules that exert antagonistic activity against closely related and unrelated group of bacteria. This review is aimed at bringing to lime light the various class of bacteriocins mainly from gram positive bacteria. The desirable characteristics of the bacteriocins which earn them a place in food preservation technology, the success story of the same in various food systems, the various challenges and the strategies employed to put them to work efficiently in various food systems has been discussed in this review. From the industrial point of view various aspects like the improvement of the producer strains, downstream processing and purification of the bacteriocins and recent trends in engineered bacteriocins has also been briefly discussed in this review.     

水解方式对黄茧蚕丝多肽抗氧化活性的影响

以DPPH自由基清除率为指标,研究了天然黄茧家蚕品种"金丝一号"茧丝在盐水解、碱水解、酶水解3种不同提取条件下所获蛋白多肽的抗氧化功能活性差异。结果表明:盐水解法时,在40%CaCl_2溶液、100℃、料液比为1∶20(g/mL)的提取条件下,蚕丝蛋白多肽DPPH自由基清除率平均为43.15%;碱水解法时,在4 mol/L NaOH溶液、100℃的条件下提取1 h,DPPH自由基清除率平均为45.62%。酶水解法时,加入1 000 U/g碱性蛋白酶,55℃处理4 h,蚕丝蛋白多肽DPPH自由基清除率平均为62.26%。天然黄茧蚕丝蛋白酶法水解物的抗氧化活性优于盐水解法和碱水解法。