植物沥青中角鲨烯的富集及分离提纯研究

研究了植物沥青中角鲨烯的富集及分离提纯工艺。通过冷析离心和分子蒸馏对植物沥青中角鲨烯进行一定量的富集后,考察了溶剂极性、吸附剂用量和吸附时间对提纯后的角鲨烯含量和收率的影响。在单因素实验的基础上,通过正交实验优化提纯工艺条件,得出最佳工艺条件为:采用丙酮与石油醚(体积比30∶70)作为溶剂,吸附剂的量分别为硅胶与样品质量比1∶1、活性炭与样品质量比3∶1。在最佳工艺条件下,角鲨烯的含量和收率分别达到了87.34%和88.69%。     

大豆油脱臭馏出物中同时提取角鲨烯、生育酚和植物甾醇的工艺研究

采用酯化—高真空蒸馏工艺路线,从大豆油脱臭馏出物中同时提取角鲨烯、生育酚及植物甾醇。考察酯化条件(甲醇、催化剂浓硫酸用量及反应时间)对酯化率、角鲨烯和生育酚含量的影响。优化得到的最佳工艺为:催化剂浓硫酸添加量0.5%,醇油摩尔比10∶1,反应温度70℃,反应时间120 min,大豆油脱臭馏出物酯化率达到98.2%,生育酚和角鲨烯保留率分别为97.7%和97.5%。酯化后的物料通过冷析结晶,抽滤得到植物甾醇粗品,滤液高真空蒸馏,初步分离得到脂肪酸甲酯、角鲨烯、生育酚等组分。各组分中角鲨烯富集到12.2%,生育酚富集到28.6%,植物甾醇富集到60%左右,初步实现了大豆油脱臭馏出物中角鲨烯、生育酚、植物甾醇的同时提取,为角鲨烯、生育酚及植物甾醇的进一步富集提供了参考依据。     

硅胶柱色谱制备高纯1,3-二油酸甘油二酯的研究

以实验室自制1,3-二油酸甘油二酯粗品(含量76.41%)为原料,采用硅胶柱色谱法制备高纯1,3-二油酸甘油二酯。通过硅胶薄层色谱对4种混合溶剂洗脱剂进行筛选,确定硅胶柱色谱最佳洗脱剂为D(正己烷-乙酸乙酯-乙醚-乙酸的混合液)。以1,3-二油酸甘油二酯的回收率和纯度为指标,系统考察了硅胶柱色谱的洗脱流速、上样质量浓度、硅胶量对纯化效果的影响,确定最佳硅胶柱色谱纯化条件为:洗脱流速1.5 m L/min,上样质量浓度75 mg/m L(上样体积10 m L),硅胶量30 g。该条件下制得的1,3-二油酸甘油二酯样品纯度达98.03%,回收率为69.90%。     

樟芝发酵产物中安卓奎诺尔的提取纯化

对樟芝发酵产物中的生理活性物质安卓奎诺尔的提取纯化工艺技术进行了研究。结果表明,安卓奎诺尔的最佳的提取条件为:提取溶剂为95%乙醇,料液比1∶25(g/m L),提取温度为35℃,提取时间为85 min。提取液再经过二次柱层析进一步纯化。第一次硅胶柱层析最佳条件为:上样量1∶40(w样品∶w硅胶),径高比1∶30,洗脱流速2.0 BV/h,产物中安卓奎诺尔的纯度为70.2%;第二次硅胶柱层析最佳条件为:洗脱剂v苯∶v丙酮=7∶3,上样量w样品∶w硅胶=1∶30,径高比1∶10,洗脱流速1.0 BV/h,最终产品中安卓奎诺尔的纯度达到91.0%。     

西兰花副产物中萝卜硫素提取、纯化及鉴定

以西兰花副产物为原料,研究萝卜硫素酶解浸提工艺,并通过单因素试验和响应面试验优化最佳工艺条件。在最佳条件的基础上进行放大实验,通过半制备高效液相色谱纯化和富集萝卜硫素,并应用超高效液相色谱-质谱联用技术对纯化物进行鉴定。结果表明：萝卜硫素最佳提取条件为酶解pH 5.0、酶解温度35 ℃、酶解时间67 min;在此条件下,萝卜硫素提取量为151.39 μg/g,与预测值（156.33 μg/g）无显著差异;纯化和富集后,得到28.62 mg/200 g萝卜硫素,回收率为94.52%,纯度为80.74%。根据萝卜硫素的二级质谱与碎片离子信息,进一步确定该纯化物为萝卜硫素。     

大豆油脱臭馏出物中角鲨烯提取工艺研究

以大豆油脱臭馏出物为原料,采用碱性乙醇对其进行皂化处理并分离不皂化物。以不皂化物中角鲨烯含量为指标,在单因素试验基础上,研究了反应温度、反应时间、碱浓度、料液比对角鲨烯含量的影响,最后进行正交试验优化大豆油脱臭馏出物中角鲨烯的皂化提取条件。结果表明最佳提取工艺条件为:反应温度90℃,反应时间40 min,碱浓度1.6 mol/L,料液比1∶2。在最佳工艺条件下用正己烷提取3次,角鲨烯含量和收率分别为10.34%和77.59%。     

大孔树脂-硅胶柱层析法纯化花生根中白藜芦醇

研究了大孔树脂-硅胶柱层析法分离纯化花生根中白藜芦醇的工艺。通过动静态解吸附试验确立大孔树脂最佳分离工艺为:大孔树脂为聚酰胺,上样质量浓度26.58μg/mL,解吸剂为80%乙醇,洗脱流速2 BV/h。通过薄层色谱与硅胶柱层析试验,确定最佳纯化条件为:洗脱剂V(氯仿)∶V(甲醇)=40∶1、流速30 mL/min、m(硅胶)∶m(样品)=1∶1。产物经V(甲醇)∶V(氯仿)=3∶1重结晶后,采用高效液相色谱测定其纯度为97.01%。     

明日叶中4-羟基德里辛和黄色当归醇的提取纯化及鉴定

明日叶是一种药食两用的绿色蔬菜,极具开发价值。本文以明日叶为原料,首先通过单因素以及正交试验,优化了明日叶中4-羟基德里辛(4-HD)和黄色当归醇(XAG)的提取工艺参数。其次采用乙酸乙酯萃取、硅胶柱层析以及半制备液相相结合的方法对粗提液中的4-HD和XAG进行分离纯化,并对纯化物的结构及纯度进行分析。结果表明:最佳提取条件为:提取2次、提取溶剂80%乙醇、提取温度55℃、提取时间90 min、料液比1∶10。此时,4-HD得率为1.82 mg/g,XAG得率为2.12 mg/g。HPLC-MS及NMR分析结果表明:纯化得到的两种物质正是4-HD和XAG,纯度分别为99.08%和98.92%。     

蛋黄来源磷脂酰乙醇胺的富集、纯化及脂肪酸组成研究

对蛋黄粉进行磷脂酰乙醇胺(PE)富集、分离纯化,采用单因素实验考察富集环节中丙酮-无水乙醇配比、溶剂倍量、洗脱时间、洗脱次数对富集PE含量的影响,并用正交实验进行优化;采用气相色谱分析了纯化蛋黄磷脂酰乙醇胺的脂肪酸组成。结果表明:PE富集的最优方案为溶剂丙酮-无水乙醇配比3∶1、溶剂倍量2倍、洗脱时间1 h、洗脱2次,富集后PE含量达到52%,富集率为70%;经硅胶柱层分离纯化后,PE纯度达99%;蛋黄磷脂酰乙醇胺骨架含有7种脂肪酸,不饱和脂肪酸含量为55. 52%,其中花生四烯酸含量达16. 40%。     

金丝新4号枣果中黄酮类物质提取及纯化工艺的研究

在单因素试验的基础上,用正交试验优化枣果黄酮类化合物提取的工艺条件;比较5种树脂的吸附作用,对最适树脂进行静态和动态吸附试验;进一步用硅胶柱层析纯化,薄层层析检测.最佳提取条件:60%乙醇为提取溶荆,料液比1:20(W:V),55℃下提取2次,每次2 h,枣果黄酮类化合物的提取率可达80.78%,纯度为15.27%;HPD-417型树脂对枣果黄酮类化舍物的吸附量为69.21 mg/g,解吸率为90.7%.最佳操作条件:上样液浓度15 mg/mL,pH 6.0,流速2.0 mL/min,所得枣黄酮纯度为81.59%;经硅胶柱层析进一步纯化所得枣黄酮纯度为97.98%.     

植物油中角鲨烯的提取与高效液相色谱法分析

建立了硅胶柱提取,高效液相色谱法分析植物油中角鲨烯的方法.样品用石油醚溶解,过硅胶柱净化,经C18柱分离,紫外检测(210 nm).结果表明,角鲨烯与其他杂质峰得到良好分离,在2～1 000 mg/L浓度范围内,峰面积与浓度呈良好线性,线性相关系数(R2)0.998.在大豆油中添加5.0、100、500和1 000mg/kg水平的角鲨烯,平均加标回收率为82.4％～ 89.3％,相对标准偏差小于7.1％(n=8),方法测定低限(LOQ)5 mg/kg.本方法准确、灵敏、可靠,已应用于实际样品分析.     

Stability of potassium iodide and omega-3 fatty acids in fortified freshwater fish emulsion sausage

Oxidative stability of emulsion sausages prepared from African walking catfish (AF: Clarias gariepinus) and rohu (RH: Labeo rohita) fortified with three levels of the refined tuna oil (2%, 6%, and 10%) with 150 μg KI/100 g sample and without KI was investigated. The control was prepared using 20% soybean oil and without KI. Samples were vacuum-packed and stored at 4 °C. Iodine content decreased approximately 14% after cooking and remained constant throughout storage. Sausages fortified with tuna oil showed higher level of n-3 (eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)), but lower level of n-6 fatty acids (P<0.05) than the control. The ratio of n-6 to n-3 fatty acids of all samples decreased with an increase of tuna oil addition and was stable throughout 4 weeks of storage. Degradation of linoleic (LA) and linolenic acid (LNA) mainly occurred in the samples added 2% tuna oil whereas samples fortified with higher tuna oil (6-10%) exhibited higher loss of EPA and DHA. Hydroperoxide (HPV) and thiobarbituric reactive substances (TBARS) values were increased as addition level of tuna oil increased. Textural properties were not affected during storage at 4 °C for up to 4 weeks (P<0.05). Based on lipid stability results, 2% fortification of the refined tuna oil was recommended for emulsion sausage prepared from both species. Addition of 150 μg KI/100 g had no effect on lipid oxidation of fish sausages (P<0.05).     

Antioxidative properties of Pandanus amaryllifolius leaf extracts in accelerated oxidation and deep frying studies

The potential uses of Pandanus amaryllifolius leaf extract as a natural antioxidant were evaluated in refined, bleached and deodorized (RBD) palm olein, using accelerated oxidation and deep frying studies at 180 °C from 0 to 40 h. The extracts (optimum concentration 0.2%) significantly retarded oil oxidation and deterioration (P < 0.05), comparably to 0.02% BHT in tests such as peroxide value, anisidine value, iodine value, free fatty acid, oxidative stability index (OSI), polar and polymer compound contents. In sensory evaluation studies, different batches of French fries were not significantly different (P < 0.05) from one another for oiliness, crispiness, taste and overall acceptability when the same oil was used for up to the 40th hour of frying. P. amaryllifolius leaf extract, which had a polyphenol content of 102 mg/g, exhibited an excellent heat-stable antioxidant property and may be a good natural alternative to existing synthetic antioxidants in the food industry.     

The Fate of Organophosphorus Pesticides during Camellia Oil Production

The purpose of this study was to investigate the fate of organophosphorus pesticides (OPs) during camellia oil production process, from camellia fruit to the final oil product. The results showed that the OPs were mainly distributed in the peel of camellia fruit, basically above 40% after the pesticide application of 7 d (P < 0.05). A small amount of OPs could enter into the seed and convert to crude camellia oil, with the concentration of 19.5 to 548.2 mg/L. In addition, metabolites of OPs (25.7 to 768.9 mg/L) could be detected in the crude camellia oil. M8oreover, the refining process (degumming, deacidfying, bleaching) had a significant effect on the removal of OPs from the crude camellia oil (P < 0.05), and the effect was related to the octanol–water partition constant (LogP) of pesticide. The larger the LogP, the more stable the OPs were during refining process. The final refined camellia oil was found to have no detectable levels of OPs metabolite.     

Developing radio frequency pretreatment technology for improving yield and quality of flaxseed oil extractions

Flaxseed is considered as a major raw material for producing functional vegetable oil. To promote the extraction process of flaxseed oil, effects of radio frequency (RF) pretreatment at investigated temperatures (70, 90, 110, 130, and 150 °C) on yield, physicochemical property and sensory quality of flaxseed oil were determined. The results showed that the yield of flaxseed oil increased from 31.29 to 38.23% after RF pretreatment at 150 °C (p < 0.05). The total phenolic, lignan, antioxidant capacity, chlorophyll, and carotenoid contents of flaxseed oil increased significantly with the increase of RF pretreatment temperature (p < 0.05). Nonetheless, the higher RF pretreatment temperatures caused a slight increase on oil oxidation indices (free fatty acid, peroxide value, conjugated diene, conjugated trienes, and p-anisidine value). These results provide theoretical guidance for practical applications of RF pretreatment in the production and processing of edible vegetable oil.     

不同制油工艺对酸木瓜籽油成分及氧化稳定性的影响

目的 研究低温压榨、高温压榨和超声波辅助溶剂提取3种不同制油工艺对酸木瓜籽油提取率、成分及氧化稳定性的影响。方法 利用气相色谱-质谱法(gas chromatography-mass spectrometry, GC-MS)对木瓜籽油脂肪酸组成和挥发性成分进行分析;采用schaal烘箱法加速氧化,以酸价和过氧化值为指标对木瓜籽油氧化稳定性进行评估。结果 超声波辅助溶剂提取法出油率最高,其中不同溶剂提取以二氯甲烷最佳,出油率达44.21%;不同制油工艺对酸木瓜籽油脂肪酸组成影响很小,共鉴定出7种脂肪酸,相对含量最高的是油酸,其次是亚油酸、棕榈酸、硬脂酸,其中不饱和脂肪酸占比可达80.35%;在酸木瓜籽油中鉴定出47种挥发物,以烷烃类为主,溶剂法与压榨法制取的木瓜籽油挥发物组成差异较大,其中以2,4-二叔丁基苯酚和反式角鲨烯为首,溶剂法制得的油中2,4-二叔丁基苯酚占比为23.94%,反式角鲨烯占比为4.14%,而由低/高温榨取法制得的油中2,4-二叔丁基苯酚占比分别为3.20%和2.77%,反式角鲨烯占比分别为29.15%和23.38%;低温压榨制油清除1,1-二苯基-2-三硝基苯肼(1...     

Effects of Particle Size,Applied Pressure and Pressing Time on the Yield of Oil Expressed from Almond Seed

An investigation of the effects of particle size, applied pressure and pressing time on the yield of oil expressed from almond seeds was undertaken. The oil was expressed mechanically using a mini laboratory oil press. The fixed processing parameters were: moisture content of 17% wet basis, heating temperature of 65 – 70°C and heating time of 15 min. The pressing pressures used were 60.6 kPa, 101.3 kPa and 116.6 kPa. Pressing times used were 2, 4, 8 and 12 min, and particle size of Φ < 0.5 mm (fine sample) and Φ > 0.5 mm (coarse sample) were used. The result shows that oil yield increased with increase in applied pressure and pressing time, however result obtained from fine and coarse sample sizes are similar. Pressing time and applied pressure had significant (p < 0.05) difference on oil yield; particle size had no significant (p > 0.05) difference on oil yield. Regression and correlation analysis gave a reasonable experimental prediction between oil yield and applied pressure with correlation coefficient r = 0.952 and also with pressing time with r = 0.7342. Higher oil yields were obtained from samples with fine particles size (Φ < 0.5 mm) and coarse particles size (Φ > 0.5 mm) samples pressed at 116.6 kPa pressure for 12 min. Maximum oil yields of 48.44% and 48.40% were obtained from coarse and fine samples respectively. The results obtained can be used in the design of a suitable process and machine for the expression of oil from almond seed.     

金刚藤白藜芦醇的纯化及抗氧化活性研究

采用超声波辅助提取金刚藤白藜芦醇,得到粗提物,再利用硅胶柱层析对粗提物进行纯化,然后通过白藜芦醇对油脂抗氧化及对羟基自由基、超氧阴离子自由基的清除效果,研究金刚藤白藜芦醇的抗氧化活性。结果表明:从金刚藤中提取白藜芦醇的得率为2.36%;金刚藤白藜芦醇具有较强的抗油脂氧化和清除自由基的能力,当金刚藤白藜芦醇质量浓度为8 mg/mL时,对羟基自由基和超氧阴离子自由基的清除率分别为71.91%和75.14%;提取物经过纯化后,抗氧化活性明显增强。     

Quality assessment of refined oil blends during repeated deep frying monitored by SPME–GC–EIMS,GC and chemometrics

The aim of this study was to investigate the effect of the refined palm oil addition (20%) on the fatty acid and sterol compositions of refined olive oil or refined soya bean oil and also to investigate the formation of total polar compounds and volatile compounds in these oil blends during fifty successive deep‐frying sessions of potato fries at 180 °C. The blend of refined olive oil and refined palm oil exhibited a higher chemical stability during the frying process than that of refined soya bean oil and refined palm oil. Indeed, the total polar compounds and volatile compounds formed, especially 2,4‐decadienal, were found to be relatively increased in the refined soya bean oil/refined palm oil blend reaching 36.50% and 46.70%, respectively, after fifty deep‐frying sessions. Moreover, the degradation of linoleic acid and β‐sitosterol was significantly (P < 0.05) observed for the refined soya bean oil/refined palm oil blend. The results have proven that the proper blending of monounsaturated refined olive oil with refined palm oil increases its stability and hence improves the quality of such olive oil during frying process.     

Preparation and characterisation of protein concentrates from defatted kenaf seed

Two kenaf varieties QP3 and V36 were used to obtain protein concentrates. Proximate analysis, foaming, water and oil absorption properties were studied. Significant (P < 0.05) differences were observed among the two varieties only in their content in oil and carbohydrates. The protein concentrate yield was 13.04% and 10.56%, respectively. The two varieties showed significantly different (P < 0.05) water and oil absorption capacities. QP3 showed higher foaming capacity than did V38, and it was increased with increasing salt and sugar concentration. Albumin was the main fraction representing 59.6% and 66.1% in QP3 and V36 varieties, respectively, followed by globulin, which represented 22.6% and 19.1%, respectively. The ratios of albumin, globulin, glutelin and prolamin were significantly different. Based on the data obtained from sodium dodecyl sulphate polyacrylamide gel electrophoresis, the main kenaf seed proteins present in the concentrates were five proteins with molecular weights ranging from 10 to 66 kDa. From differential scanning calorimetry data, QP3 and V36 protein concentrates had similar denaturation temperatures (82.6 and 81.8 °C, respectively).