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1.
The objective of this research was to investigate the physicochemical properties of donkey fat. Results show that donkey fat contains 59.38 % unsaturated fatty acids, 38.37 % saturated fatty acids, and 0.21 % trans fatty acids. The sn-2 monoglyceride present in donkey fat contain 67.91 % unsaturated fatty acids and 30.97 % saturated fatty acids. Donkey fat is also characterized by a total tocopherol content of 8.59 mg/100 g fat (7.90 mg/100 g fat α-tocopherol, 0.51 mg/100 g fat β + γ-tocopherol, and 0.18 mg/100 g fat δ-tocopherol), 0.0032 mg/100 g fat cholesterol, an acid value of 0.091 KOH (mg/g), an iodine value of 76.47 g/100 g, a peroxide value of 0.68 mmol/kg, a saponification value of 193 mg/g, a refractive index of 1.4666, and a specific gravity of 0.9144. The complete melting temperature was 40 °C. The content of unsaturated fatty acids (total and sn-2) in donkey fat is higher than cow, pig and sheep, while the content of trans fatty acids is lower. The tocopherol content is also higher in donkey fat compared to cow, pig and sheep fat. Interestingly, the fat with such processing has nearly no cholesterol. Generally speaking, donkey fat could be a good animal fat for human consumption.  相似文献   

2.
毛叶山桐子油中脂肪酸组成分析   总被引:1,自引:0,他引:1  
以毛叶山桐子毛油为原料,利用容量分析方法测定其酸值、碘值及皂化值。以甲酯化方法对山桐子油进行处理后,用GC-MS法对脂肪酸组成和相对含量进行测定,结果显示其碘值为52.15g·(100g)^-1,皂化值195.39mgKOH·g^-1,主要脂肪酸为反式-9,12-十八碳二烯酸、棕榈酸、棕榈油酸等,反式-9,12-十八碳二烯酸含量最高,达59.54%。  相似文献   

3.
水厂深度处理工艺中臭氧投加量探讨   总被引:1,自引:1,他引:0  
臭氧生物活性炭深度处理是降低水中微量有机物的关键净化工艺。为确定臭氧的合理投加量,利用小试装置开展了臭氧氧化对砂滤池出水的研究。结果表明:随着臭氧投加量的增加,CODMn、总有机碳(TOC)的去除率均有所增加,但幅度弱于UV254;当臭氧的投加量达到3.0 mg/L时,臭氧氧化后的生物可降解溶解性有机碳(BDOC)可增加30%以上,UV254与TOC的比值趋于稳定;砂滤出水的溴离子浓度为100~300μg/L的情况下,当臭氧的投加量达到3.5 mg/L时仍未检测到溴酸盐。综上所述黄浦江原水水厂深度处理工程运行时,臭氧的投加剂量控制在2.5~3.5 mg/L是安全合理的。  相似文献   

4.
以木薯酒精厂生产过程中产生的脱水污泥为原料,采用响应曲面法 Box-Behnken模型优化了木薯酒精污泥基活性炭的制备工艺,同时对最优成品进行一系列表征分析,并将其应用于没食子酸废水的处理研究。活性炭的最优制备条件为活化温度489℃,浸渍时间14 h,活化时间51 min,氯化锌浓度21.53%,该条件下样品的碘吸附值达521.64 mg/g。表征分析显示其表面布有众多孔壁较薄、大小不一的孔洞,金属含量较小,BET比表面积达441.86 m2/g,平均孔径为2.50 nm,拥有丰富的微孔结构,表面富有较多的含氧官能团。考察了活性炭投加量、pH、接触时间、溶液温度对样品去除水中没食子酸的影响。结果表明,样品能够高效去除没食子酸,且随着投加量的增加和pH值降低,没食子酸的去除率呈增长趋势。木薯酒精污泥基活性炭对没食子酸的吸附符合pseudo second-order动力学模型和Freundlich等温模型,最大吸附量为126.72 mg/g。扩散机理显示除颗粒内扩散外也包含液膜扩散过程。热力学分析表明该吸附反应是自发进行的吸热且熵增的过程。本研究将为制备高性能污泥活性炭并应用于高浓度天然有机物废水处理提供理论基础。  相似文献   

5.
几种食用油中不饱和脂肪酸和皂化值的测定研究   总被引:3,自引:0,他引:3  
以茶籽油、玉米油、橄榄油、芝麻油、花生油为原料,利用容量分析方法测定其不饱和脂肪酸含量及皂化值.经碘酊法测定,这5种食油用的不饱和脂肪酸含量(以碘值衡量)最高的为茶籽油,达95.46g·(100g)-1,碘值最低的为花生油54.67g·( 100g)-1.这5种植物油碘值由大至小依次为:茶籽油>玉米油>橄榄油>芝麻油>...  相似文献   

6.
High-pressure effects on lipid oxidation   总被引:4,自引:0,他引:4  
Rendered pork fat (0.44 water activity, Aw) was subjected to high-pressure treatment of 800 MPa for 20 min at 19°C prior to storage at 4, 25, and 50°C. In all cases, high pressure-treated samples oxidized more rapidly (had a shorter induction period) as shown by the peroxide value (PV), 2-thiobarbituric acid value, and ultraviolet absorbance. The effect was less marked at lower pressures. In contrast, at all water activities outside the range of 0.40–0.55, the PV of the high pressure-treated pork fat was lower than control samples stored similarly, and the PV of rancid fat decreased slightly on pressure treatment at 19°C, but not at higher temperatures. This effect may explain the observed inhibition of oxidation at most water activities. At 0.40–0.55 Aw, other factors, such as the liberation of transition metals, may override the destruction of peroxides.  相似文献   

7.
O3-BAC工艺预臭氧投加量优化的中试研究   总被引:1,自引:0,他引:1  
通过设计规模为5~15 m3.h-1的中试装置对O3-BAC工艺给水处理时预臭氧投加量进行了优化研究。结果表明,预臭氧投加量为0.5 mg.L-1时,沉淀池出水浊度为0.68 NTU,助凝效果最强,对比零投加量时,浊度去除绝对值为0.34 NTU;藻类灭活率为77.77%,细菌的灭菌率为84.1%,总大肠杆菌群的灭菌率为98.9%,灭藻灭菌综合效果最好。同时预臭氧对UV254、CODMn具有一定的去除效果,去除率随臭氧投加量增加而略有上升趋势。综合分析,针对Ⅱ~Ⅲ类水源,建议O3-BAC工艺给水处理预臭氧量最佳投加量为0.5 mg.L-1。  相似文献   

8.
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.  相似文献   

9.
考察了竹活性炭不同碘吸附值及吸附时间对甲醛吸附量的影响。结果表明:随着碘吸附值增加,竹活性炭对甲醛吸附能力也增加,在72 h内碘吸附值最高竹活性炭(744.16mg/g)其甲醛吸附能力为碘吸附值最低竹活性炭(126.83 mg/g) 的2.63倍,通过SPSS软件分析得出,竹活性炭碘吸附值与甲醛吸附成正相关,在72 h内以24 h甲醛吸附量为基准,对每隔24 h甲醛吸附增加值进行比较。结果表明竹活性炭碘吸附值越大,吸附时间越长,竹活性炭对甲醛吸附增加值也越大,且两者之间成正相关。进一步以竹活性炭碘吸附值(X1)和吸附时间(X2)为变量进行回归分析,得出回归方程:Y=66.215lnX1+0.973X2-286.66,相关系数R2为0.948。  相似文献   

10.
The objective of this study was to determine the fatty acid composition and physicochemical properties of ostrich fat obtained by supercritical fluid extraction. The fatty acid composition was analysed by GC‐MS and the result revealed that ostrich fat contained 9‐octadecenoic acid (40.7 ± 0.3%), hexadecanoic acid (32.5 ± 0.3%), octadecanoic acid (7.43 ± 0.05%), 9, 12‐octadecadience acid (7.38 ± 0.02%) and 9‐hexadecenoic acid (7.13 ± 0.15%) as the major components. Furthermore, seven physicochemical indexes were assessed according to Chinese Pharmacopeia (2005) and relevant regulations as follows: relative density (0.92 ± 0.02%), melting point (34.7 ± 0.4°C), acid value (0.84 ± 0.02 mg KOH/g), peroxide value (0.10 ± 0.01 g/100 g), saponification value (226 ± 3 mg KOH/g), ester value (225 ± 3 mg KOH/g) and iodine value (74.6 ± 0.8 g I/100 g). It can be inferred from the basic information that ostrich fat is a promising raw material for the pharmaceutical and cosmetics industries. Practical applications : With the increasing attention being paid to ostrich fat, it is necessary to elucidate the fatty acid composition and physicochemical properties of this natural product. This basic information not only reveals the essential characteristics of ostrich fat, but also provides the data support for the quality evaluation and efficacy research.  相似文献   

11.
A primary Fourier transform infrared (FTIR) spectroscopic method for the determination of peroxide value (PV) in edible oils was developed based on the stoichiometric reaction of triphenylphosphine (TPP) with hydroperoxides to produce triphenylphosphine oxide (TPPO). Accurate quantitation of the TPPO formed in this reaction by measurement of its intense absorption band at 542 cm−1 provides a simple means of determining PV. A calibration was developed with TPPO as the standard; its concentration, expressed in terms of PV, covered a range of 0–15 PV. The resulting calibration was linear over the analytical range and had a standard deviation of ±0.05 PV. A standardized analytical protocol was developed, consisting of adding ∼0.2 g of a 33% (w/w) stock solution of TPP in hexanol to ∼30 g of melted fat or oil, shaking the sample, and scanning it in a 100-μm KCI IR transmission cell maintained at 80°C. The FTIR spectrometer was programmed in Visual Basic to automate scanning and quantitation, with the reaction/FTIR analysis taking about 2 min per sample. The method was validated by comparing the analytical results of the AOCS PV method to those of the automated FTIR procedure by using both oxidized oils and oils spiked with tert-butyl hydroperoxide. The two methods correlated well. The reproducibility of the FTIR method was superior (±0.18) to that of the standard chemical method (±0.89 PV). The FTIR method is a significant improvement over the standard AOCS method in terms of analytical time and effort and avoids solvent and reagent disposal problems. Based on its simple stoichiometry, rapid and complete reaction, and the singular band that characterizes the end product, the TPP/TPPO reaction coupled with a programmable FTIR spectrometer provides a rapid and efficient means of determining PV that is especially suited for routine quality control applications in the fats and oils industry.  相似文献   

12.
The oxidation of several VOCs in the presence of humic acid and soil is described in this paper. It was found that while ozone does react appreciably with humic acid, as indicated by significant changes in the spectral characteristics of humic acid, the TOC levels in these solutions changed by only 3‰ or less. The oxidation of four olefinic VOCs occurred in solutions containing up to 120 mg/L humic acid, however, the extent to which each of the compounds reacted is very much compound specific. The effect of pH and ozone dosage on these reactions was considered. The effects of pH were weak for all compounds except trichloroethane. Ozone dosage had a significant effect on the extent to which each of the VOCs was oxidized, although no simple relationship between ozone dosage and the amount of VOC which reacted could be obtained. Complete oxidation of dy–dichloroethylene by ozone (22 mg/L) occurred in solutions containing 1.0 g of Eustis soil suspended in 10.0 mL water. However, only 40‰ oxidation of tetrachloroethylene was achieved using an ozone dosage of 17.3 mg/L when 1.0 g of Eustis soil was present. The results obtained in this study strongly suggest that the influence of free radicals, generated during the decomposition of ozone, on the oxidation of VOCs is significant. The work described here suggests that ozone may be applicable for the treatment of contaminated soils and waters containing high concentrations of matter.  相似文献   

13.
两步法催化高酸价微藻油脂制备生物柴油   总被引:2,自引:1,他引:1  
研究了两步法催化高酸价微藻油脂制备生物柴油的工艺条件。测定从产油栅藻培养物中提取的油脂的化学成分,发现油脂的游离脂肪酸含量分布在10%~32%,极性脂含量分布在21%~46%。以此高酸价、高极性脂含量油脂,经过酸预酯化-碱催化转酯化两步法制备生物柴油。其最优反应条件为:30%的醇加入量,1%油质量的硫酸催化反应2 h,其油脂酸价可从初始酸值的17~46 mg/g降低至2 mg/g以下;随后,在醇油物质的量之比为12:1,催化剂氢氧化钾用量为油质量的2%,65℃条件下反应30min,制备所得生物柴油中脂肪酸甲酯的质量分数可达96.6%,甘油三酯的转化效率接近100%。根据《柴油机燃料调合用生物柴油》国家标准,测定了微藻生物柴油产品的品质指标,发现其密度、运动黏度、酸价、氧化安定性等各项指标均符合国家标准(GB/T 20828-2007);热值为39.76 MJ/kg,符合欧盟生物柴油标准(EN 14214)。  相似文献   

14.
以椰子油为原料,通过液相裂解法和气相催化裂解法制备高品位的生物燃料。在温度450℃、进气速率30 mL/min、反应时间45 min的液相裂解条件下,椰子油液相裂解的液体产率达到最大为76.5%,但裂解液酸值较高,在100 mg/g以上。为了降低裂解液酸值,以纳基膨润土为载体,CaO作为催化剂,对液相裂解产物之一的裂解液进行气相催化裂解。研究结果表明:在温度400℃、催化剂CaO用量15%的条件下,椰子油气相催化裂解的液体产率峰值为69.5%,酸值为26.8 mg/g;在温度450℃、催化剂CaO用量30%的条件下,椰子油气相催化裂解的液体产率为64.1%,酸值为2.8 mg/g,此时酸值最低。经GC-MS分析可知,液相裂解液中主要包含烃类、酮类和酸类等组分,其质量分数分别为32.6%、24.2%和43.3%,而气相催化裂解液中烃类物质增加23.3个百分点,不利的酸、酮类物质则分别降低18.8和4.6个百分点。与椰子油相比,液相裂解的液体产物运动黏度与含氧量降低,酸值与低位热值升高;与液相裂解液相比,气相催化裂解的液体产物的酸值与含氧量降低,热值升高。经气相催化裂解得到的生物燃料和0#柴油更为接近。  相似文献   

15.
李欣欣  解立平  王蒙  张璐 《化工进展》2020,39(2):760-766
设计了一种具有回流的固定床臭氧催化氧化反应装置,对浸渍法制得的α-Fe2O3/γ-Al2O3催化剂的性能进行了表征,并利用其在回流固定床反应装置中对煤化工反渗透浓水的臭氧催化氧化性能进行了研究。结果表明:α-Fe2O3/γ-Al2O3的比表面积、平均孔径、总孔容和活性组分α-Fe2O3含量分别为161.74m2/g、10nm、0.4533cm3/g和8.73%。反渗透浓水COD去除率随催化剂装填高度、臭氧投加浓度和过氧化氢投加量的增加而均呈现为先增加、后降低的变化趋势,回流可显著地提高废水COD去除率,适宜的催化剂装填高度、臭氧投加浓度、过氧化氢投加量和回流比分别为350mm、300mg/L、150mg/L和50%,臭氧催化氧化反渗透浓水的COD去除率达74.33%。煤化工反渗透浓水中大部分溶解性有机物和腐殖酸类物质均被臭氧催化氧化分解。  相似文献   

16.
利用自动电位滴定仪建立了用一次微分终点滴定法测定轻柴油碘值的新方法。对实验条件及一些影响因素进行了必要的讨论。与SH/T0234—92轻质石油产品碘值和不饱和烃含量测定法相比,该法具有终点判断简单,操作简便,测定重复性好等优点;一次测定时间平均20 min,比SH/T0234—92法平均减少28min,试剂用量减少约1/2。  相似文献   

17.
Camelina sativa is an alternative, low input oilseed crop with oil of high nutritional value. In Slovenia, C. sativa landrace has been grown by local farmers in the Koro?ka region since the middle of the 20th century. In our study, we determined oil and glucosinolate content (GLS) of camelina seed and free fatty acid (FFA), peroxide value (PV), iodine value (IV), tocopherol contents (T), and fatty acid profile of camelina oil from ten locations over three consecutive growing seasons. The oil content ranged from 28.78 to 40.21%, while IV, PV, and FFA fell into a range that makes this oil useful in various nutritional applications. Camelina was remarkably rich in essential n ? 3 α‐linolenic acid (33.32–37.65%) and γ‐T (532–798 mg/kg) in oil, and GLS (16.39–41.43 µmol/g) in seed. Due to observed variability, it seems that the seed and oil characteristics of C. sativa landrace are affected by the local environmental conditions at a specific farm location and by variable genotypes between farms as a result of a more than half a century of environmental selection. Practical applications: Camelina sativa landrace in Koro?ka, Slovenia has a long history. The agricultural environment together with the traditional diet of this region ensures preservation of this landrace and limits diffusion of modern hybrids. This plant variety has not been characterized yet. The important seed and oil quality parameters presented in this work will be useful for the determination of the nutritional value of the oil, recognizing Slovenian camelina oil as a unique vegetable oil with specific geographic origin as well as focal point for plant breeders.  相似文献   

18.
对利用废食用油制备生物柴油的预酯化-酯交换工艺进行了研究。结果表明,预酯化的最佳工艺条件为:乙醇用量为80 mL、催化剂浓硫酸用量为1 g、反应时间为3 h、反应温度为70℃;酯交换的最佳工艺条件为:乙醇用量为60 mL、催化剂氢氧化钾用量1 g、反应时间为40 min、反应温度为70℃。在此条件下可使50 mL废食用油的酸值由40.27 mg KOH/g降到1.52 mg KOH/g,粗生物柴油的产率可达93.71%。  相似文献   

19.
精对苯二甲酸产品规格的探讨   总被引:1,自引:0,他引:1  
介绍 2 0世纪 60年代阿莫柯化学公司制订的精对苯二甲酸 (PTA)产品规格以及测试方法 ,根据该公司 PTA产品新规格及洛阳石油化工总厂的生产实践 ,建议修改 PTA产品规格 ,PTA产品中的酸值 ,金属镁含量可以忽略不测量 ,灰分含量小于等于 2 6μg/g,总金属含量小于等于 3μg/a,水分小于等于 0 .2 % ,并增加测试锰含量项目  相似文献   

20.
The response of phenolic compounds as a result of long-term low open-field ozone exposure was studied in ozone-sensitive and ozone-tolerant clones of European silver birch (Betula pendula Roth). The saplings were exposed to 1.5–1.6 times the ambient (elevated) ozone and ambient air (as control) over three growing seasons from May 1996 until August 1998. Quantification by modified Folin-Ciocalteau assay showed a 16.2% increase in total phenolics in elevated ozone plants as compared to that in controls and a corresponding 9.9% increase of 10 phenolic compounds quantified by HPLC. Five nonflavonoids and five flavonoids showed 8.4% and 11.4% increases, respectively. The phenolic results indicated slightly higher ozone sensitivity of clone 5 as compared to clone 2. The most ozone-responsive phenolic compounds in clone 2 and clone 5 were (+)-catechin (CT), chlorogenic acid (CGA), 5-p-coumaroylquinic acid (5CQA), 3-p-coumaroylquinic acid (3CQA), myricetin galactopyranoside (MG), quercetin-3-O-glucuronopyranoside (QGR), and quercetin-3-O-arabinofuranoside (QA). Increased phenolic content in ozone-exposed plants was related to impaired growth and accelerated leaf senescence, indicated by enhanced autumn leaf yellowing and lower chlorophyll and Mg content. The change in carbon allocation towards defensive phenolics at the expense of growth was greater in the ozone-sensitive clone as compared to tolerant clone.  相似文献   

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