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影响酸催化乙醇法制浆的主要因素有液比、蒸煮温度、乙醇浓度、催化剂用量和保温时间.本实验以麦秆为原料,从工艺角度对麦草酸催化乙醇法制浆进行初步研究.通过单因素分析优化酸催化乙醇法制浆工艺条件. 相似文献
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比较了制备生物柴油的4种方法的优点和缺点.重点总结了所采用的固体催化剂、液体催化剂、液固催化剂工艺.对无触媒工艺也进行了介绍,包括生物催化法和临界法. 相似文献
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固体酸降解木质纤维素的研究进展 总被引:1,自引:0,他引:1
《食品工业科技》2016,(7)
合理开发与利用生物质类可再生资源是近年来研究的焦点,然而如何将其资源化利用是需要解决的热点问题。目前,催化降解木质纤维素的工艺方法种类较多,本文主要阐述了用于降解纤维素的多种固体酸催化剂,从不同方面分析了这些催化剂催化降解纤维素工艺过程的优缺点。在众多固体酸催化剂中纳米金属氧化物具有较好的应用前景。固体酸催化降解纤维素的过程较为复杂,影响因素众多,该方法的工业化应用仍需进一步探索。 相似文献
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固体酸催化合成肉桂酸异戊酯 总被引:1,自引:0,他引:1
固体酸能够代替硫酸作为酯化催化剂.评述了对甲苯磺酸、强酸性阳离子交换树脂、六水三氯化铁、聚氯乙烯-三氯化铁树脂、五水四氯化锡、十二水合硫酸铁铵、硫酸钛、一水硫酸氢钠、硫酸氢钾、固体超强酸和杂多酸等固体酸催化催化合成肉桂酸异戊酯的方法.通过评述本人认为强酸性阳离子交换树脂、六水三氯化铁、一水硫酸氢钠、固体超强酸、杂多酸和固载化的固体酸是合成肉桂酸异戊酯的良好催化剂;微波辐射是合成肉桂酸异戊酯的良好方法. 相似文献
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采用固相萃取柱净化,气相色谱-质谱联用法测定了6种植物油中脂肪酸烷基酯(包括脂肪酸甲酯和脂肪酸乙酯)的含量,并研究其在植物油煎炸、废弃及废弃油脂精炼等环节中的变化。结果发现,6种植物油中脂肪酸烷基酯的含量均低于30 mg/kg,而植物油在废弃过程中可能会形成大量脂肪酸乙酯,生成量与油脂是否烹饪及废弃物中乙醇含量有关。脂肪酸烷基酯在脱色工艺中不能被去除,但在脱臭中可被去除。因此,可以通过测定植物油中脂肪酸烷基酯含量发现废弃油脂,为废弃油脂的鉴别工作提供新的思路。 相似文献
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为了提供植物油在微波和射频等介电加热技术和通电加热技术中的应用基础数据,考察脂肪酸含量对植物油介电特性的影响,分别利用LCR阻抗测试仪和网络分析仪(同轴探针法)测量了4种植物油(橄榄油、自制橄榄油、橄榄调和油、大豆油)和5种脂肪酸(棕榈酸、硬脂酸、油酸、亚油酸、亚麻酸)在低频段(1 000 Hz~2 MHz)和高频段(300~10 000 MHz)的介电特性。结果表明:低频下,植物油的介电常数比较稳定,其均值为(1.56±0.02),介电损耗随着频率的增加而下降,其中0.7 MHz时橄榄油具有最大的介电常数(1.67±0.00)和介电损耗(7.31±0.02);高频下,植物油的介电特性随着频率的上升而缓慢下降,4种植物油之间的介电特性的差异不显著(p0.05);低频下,在植物油中加入油酸后,植物油的介电常数和介电损耗呈现先上升后下降的趋势,而添加亚油酸呈现相反的趋势。添加脂肪酸会加快油脂的氧化反应。 相似文献
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Hong‐Sik Hwang Mukti Singh Jill K. Winkler‐Moser Erica L. Bakota Sean X. Liu 《Journal of food science》2014,79(10):C1926-C1932
It was previously reported that sunflower wax (SW) had high potential as an organogelator for soybean oil–based margarine and spread products. In this study, 12 other vegetable oils were evaluated in a margarine formulation to test feasibility of utilization of SW as an alternative to solid fats in margarine and spread products containing these oils. The minimum quantity of SW required to form a gel with these oils ranged from 0.3% to 1.0% (wt.). Organogels were prepared from the vegetable oils with 3%, 5% and 7% SW and were tested for firmness as well as melting behaviors using differential scanning calorimetry. These organogels were also incorporated into a margarine formulation. All of the vegetable oil organogels produced relatively firm margarines. The margarines prepared from organogels containing 3% (wt.) SW had greater firmness than commercial spreads, whereas margarines made from 7% SW were softer than commercial stick margarines. However, dropping points of the margarine samples were higher than those of commercial spread and margarine products. Margarine firmness was modestly inversely correlated with the amount of polar compounds in the oils and did not correlate with fatty acid compositions. This study demonstrates the feasibility of using a number of healthy vegetable oils rich in polyunsaturated fatty acids to make healthy margarine and spread products by utilizing SW as an organogelator. 相似文献
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Juan Camilo Ospina-E Adriana Cruz-S José Angel Pérez-Álvarez Juana Fernández-López 《Meat science》2010
Today’s consumers look for foods which provide nutrition and pleasure, while safeguarding their health, the result of which is that they increasingly avoid foods containing cholesterol and saturated and trans fatty acids. Chemically modified vegetable oils can help tailor meat products to meet this growing need and at the same time fulfil the technological needs of the meat processing industry. In this study, 16 backfat samples were characterised for their solid fat content (SFC) and melting point and these characteristics were used to design a mixture of chemically modified vegetable oils for use as a pork fat substitute for elaborating sausages. The mixtures were prepared with different vegetable oils bearing in mind with stearic acid content due to its close correlation with the SFC. The backfat was characterised as a function of its SFC and some modified vegetable oil mixtures were proposed, which led to a 10–20% diminution in saturated fatty acids and with a melting point similar to those observed in the backfat. The fatty acid profile pointed to a polyunsaturated/saturated fatty acids ratio higher than 0.4, and an n − 6/n − 3 fatty acid ratio of less than 4 in both modified vegetable oil mixtures proposed. 相似文献
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测定了12种植物油的脂肪酸组成和含量,探讨了利用植物油脂肪酸的指标对不同种类的植物油进行分类和判别的可能性。采用气相色谱法对12种植物油脂肪酸的组成和含量进行测定,利用SPSS 22. 0统计软件进行主成分分析、系统聚类、 K-平均值聚类和判别分析。结果表明:12种植物油的主要共有组成为油酸(15.635%~66.569%)和亚油酸(10.521%~58.227%),其中棉籽油(16.285%)中单不饱和脂肪酸含量最低,橄榄油(67.628%)中单不饱和脂肪酸含量最高;橄榄油(11.284%)中多不饱和脂肪酸含量最低,核桃油(67.167%)中多不饱和脂肪酸含量最高;12种植物油中不饱和度最小为棉籽油3.235,最大为低芥酸菜籽油14.672。主成分分析降维得到5个主成分,利用主成分分析数据,依次进行聚类分析和判别分析,系统聚类和K-平均值聚类结果一致,可对12种植物油聚类区别,通过判别分析建立了3个典则判别函数,对不同植物油的分类和判别的效果良好。 相似文献
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研究了四种植物油(豆油、棕榈油、花生油、芝麻油)对被孢霉菌发酵生产花生四烯酸(Arachidonic acid, AA)的影响.结果表明:(1)四种植物油显著促进了菌体油脂的积累;(2)被孢霉生长在以植物油为唯一碳源的培养基上时,菌体油脂中的AA含量比以葡萄糖为碳源时显著下降;生长在以植物油和葡萄糖为混合碳源的培养基上时,与以葡萄糖为碳源相比油脂中的AA含量仍然下降,但比生长在以植物油为唯一碳源时AA含量有所提高.说明这四种植物油对花生四烯酸的合成有抑制作用.(3)菌体油脂成分与培养基中植物油的油脂成分有一定的相似性. 相似文献
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植物油因较高的营养价值和良好的润滑性可作为食用油和工业润滑油。旨在为评价不同使用功能的植物油的氧化稳定性提供参考,从食用油和工业润滑油两方面综述了植物油氧化稳定性的检测方法,讨论比较检测方法的适用性、优缺点以及植物油在不同行业中氧化稳定性的评价指标和改善方式的差异。作为食用油,过氧化值、酸值和茴香胺值等理化指标以及氧化诱导时间是常用的评价指标;而对于工业润滑油,酸值、运动黏度和起始氧化温度是常用的评价指标。植物油的使用功能不同,其氧化稳定性研究的侧重点不同。针对指标要求的差异性选择合适的研究方法或者联合应用多个方法,对于最大程度发挥植物油的价值有重要意义。 相似文献