油料作物制油工艺现状与冷榨制油的研究进展

油脂提取所采用的工艺直接影响生产成本和成品油的品质,冷榨法作为一种相对溶剂浸提法更为安全的提油工艺,越来越受到国内外研究者的重视。介绍了当前多种制油工艺及其优势与缺陷,着重介绍了冷榨工艺的研究情况,并分析了国内外制油技术的研究现状与发展趋势。     

油料作物制油工艺现状与冷榨制油的研究进展

油脂提取所采用的工艺直接影响生产成本和成品油的品质,冷榨法作为一种相对溶剂浸提法更为安全的提油工艺,越来越受到国内外研究者的重视。介绍了当前多种制油工艺及其优势与缺陷,着重介绍了冷榨工艺的研究情况,并分析了国内外制油技术的研究现状与发展趋势。     

不同品种亚麻籽组成及抗氧化特性分析

分析了我国不同产区不同品种亚麻籽的组成及体外抗氧化特性。结果表明,除基本组成成分外,不同品种亚麻籽主要活性组分含量和体外抗氧化活性具有显著差异。α-亚麻酸、木酚素、总酚酸、黄酮、生育酚、植物甾醇含量范围分别为33.42%~59.74%,120~918 mg/100g,209~491 mg/100g,33.04~75.63 mg/100g,8.68~20.75 mg/100g,340~596 mg/100g。亚麻籽提取物DPPH值和FRAP值分别为4 357~8 146 μmol Trolox/100g, 8 289~15058 μmol Trolox/100g。此外,不同品种亚麻籽抗营养因子生氰糖苷含量差异较为显著(5.57~11.34 mg HCN/100g)。相关性分析结果表明,亚麻籽提取物体外抗氧化活性与木酚素、总酚酸和黄酮含量具有显著相关性（p<0.05）。主成分分析和聚类分析结果表明,亚麻籽主要酚类化合物及其抗氧化活性主要依赖于亚麻籽品种特性,而非种植区域。     

冷榨亚麻籽油的流变特性研究

通过低温压榨亚麻籽获得冷榨亚麻籽油(cold-pressed flaxseed oil, CFO),并分析了其主要理化指标,着重研究CFO的静态流变特性和动态流变特性,同时分别采用Casson、Herschel-Bulkley和Bingham模型对其流体行为进行拟合,并采用Arrhenius方程分析其粘度热动力学参数。研究结果表明：在剪切速率为0.1～200 s-1下,CFO由非牛顿流体逐渐转化为牛顿流体;当剪切速率大于10 s-1时,CFO呈牛顿流体;同时分析得出CFO的粘度活化能为3 095.4 cal/mol;CFO的粘度、剪切应力、损耗模量、塑性稠度系数、高剪切极限粘度和稠度系数随着温度升高而降低,但是温度变化对CFO的贮能模量影响不显著;另外通过比较3个流变模型得出Bingham模型适用于CFO。      

冷榨和热榨亚麻籽油挥发性成分比较

采用顶空固相微萃取法提取冷榨和热榨亚麻籽油中挥发性成分,借助气相质谱联用技术(GC-MS)分析并比较了挥发性成分相对含量变化.研究发现,冷榨亚麻籽油主要挥发性成分有正己醇、2-丁醇、2-甲基丁醇、戊醇、正己醛、2-乙基呋喃等,其中醇类物质相对总含量可达66％;相比而言,热榨亚麻籽油挥发性成分中醇类物质相对含量下降,出现大量美拉德反应产物糠醛及以吡嗪、吡咯、吡啶为主的芳香杂环类化合物,致使醛类(140℃,25.1％)和杂环类(140℃,41.68％)物质相对含量快速升高,这些特征挥发性成分赋予热榨亚麻籽油浓郁的烤香气味;但据研究这些芳香杂环化合物及其复合物对人体生理机能具有一定的毒理作用,因而影响到热榨亚麻籽油的食用安全性,相比较而言,冷榨亚麻籽油食用更为安全.     

火麻籽油中酚类化合物的检测及抗氧化活性研究

本文建立了采用高效液相色谱法同时检测火麻籽油中10种酚类物质的方法,10种单体酚检出限为0.05～0.12μg/mL,线性相关系数为0.9970～0.9998,回收率为85%～108%。检测了8份不同产地火麻籽油的总酚、总黄酮含量及体外抗氧化活性指标（DPPH、FRAP、ABTS+·）。总酚含量为1.20～17.35mg对香豆酸/100g,总黄酮含量为7.61～51.72mg柚皮苷/100g。DPPH清除能力为9.03～19.71mmol TE/100g,FRAP还原能力为13.12～30.09mmol TE/100g,ABTS+•清除能力为29.40～358.37mmol TE/100g。相关性分析表明,总酚含量与DPPH、ABTS+•清除能力和FRAP还原能力呈显著正相关;总黄酮含量与DPPH清除能力、FRAP的还原能力呈显著正相关。     

不同茶类特征成分抗氧化特性研究进展

简述近年关于绿茶、红茶、乌龙茶、普洱茶主要茶类特征成分抗氧化特性的研究进展,比较分析其异同点,讨论了有待进一步研究的内容,为开发茶类天然抗氧化剂的研究提供一定的参考。     

不同预处理方法对油茶籽种皮成分、结构和抗氧化活性的影响

油茶籽种皮富含多种活性成分,本文通过探讨不同预处理方法对油茶籽种皮成分、结构和抗氧化活性的影响,为实现油茶籽种皮变废为宝和深加工利用提供科学依据.对比了酸法、碱法、亚临界水和离子液体4种预处理方法所得海南油茶籽种皮中的总酚含量、纤维素组成,并运用扫描电镜(SEM)、X-射线衍射(XRD)、傅里叶变换红外光谱(FTIR)...     

余甘提职物及其制品清除自由基和抗氧化的特性

用化学发光法（CL）和顺磁共振法（ESR）测定结果表明,余甘提取物及其制品有清除活性氧的能力。通过大鼠大脑缺血、缺氧模型试验,证明余甘果汁对大脑缺血再灌的氧化损伤有防护作用。余甘提取物混入霜剂后,仍然有清除自由基的活性,而已其有效成分可透过皮肤,清除皮肤内部产生的过量自由基。该有效成分既耐热又耐贮存,因而具有较好的应用前景。     

干燥方式对槟榔理化特性和抗氧化能力的影响

本研究以槟榔为对象,采用色差、气质、液相、紫外等分析手段,研究不同干燥方法对槟榔外观形态、活性成分和抗氧化能力的影响.结果表明:槟榔的干燥速率与温度呈正相关,最快到达干燥终点的是微波干燥;干燥后槟榔外皮亮度增加,绿色度下降,黄色度提高;槟榔干制品的厚度与干燥温度呈负相关,低温的冻干可基本保持槟榔的厚度;干燥过程中槟榔的...     

亚临界流体萃取油脂及微量成分研究进展

亚临界流体萃取（subcritical fluid extraction, SFE）作为一种高效提取技术,在油脂加工中的应用备受关注。本文介绍了国内外学者关于SFE用于油脂萃取的研究成果,详细综述了SFE在不同来源油脂及微量成分提取领域的研究进展,并就目前研究状况对其前景进行了展望。      

茶叶籽油的加工工艺及其保健功效研究进展

茶叶籽油是一种纯天然高级木本可食用油脂,具有很高的营养价值和保健作用,其不饱和脂肪酸含量超过80%,维E含量丰富,具有降血脂、抗氧化及调节免疫功能、抗癌、美容护肤等保健功效。经初加工的茶叶籽油色泽深,带有苦涩味,需精加工。本文就茶叶籽油的理化特性、成分组成、加工工艺及其保健功能作一综述,以期为茶叶籽油的综合开发利用提供参考和依据。     

Effect of processing on the phenolic contents,antioxidant activity and volatile compounds of sorghum grain tea

Sorghum grain is rich in phenolic compounds and may be used to develop functional tea beverages. This work investigated the effect of processing techniques on the phenolic contents, antioxidant activity, and volatile compounds of a white colour sorghum (Liberty) grain tea. Significant (P ≤ 0.05) increase of total phenolic content, total flavonoid content and condensed tannin content were observed during the processing, whereas the antioxidant activity was not statistically enhanced. A total of 63 volatile compounds were detected including 5 alcohols, 13 alkanes, 2 aldehydes, 2 carboxylic acids, 15 esters, 4 ketones, 3 pyrazines and 1 phenylenediamine, which were affected by the processing techniques. The sorghum tea made from powder form infusion had more abundant volatile compounds compared to whole grain form infusion. The findings of this research have potential to expand human consumption of sorghum grain in the new form of grain tea.     

二氧化硅在菜籽油吸附脱磷中的应用及其对酚酸的影响

为了精炼后的油中尽可能多地保留菜籽多酚,首先通过傅里叶红外光谱分析(Fourier infrared spectrum,FT-IR)和差示扫描量热分析(differential scanning calorimetry,DSC)对二氧化硅(SiO2)和磷脂酰乙醇胺(PE)以及它们的复合物进行表征分析,然后以菜籽油为研究...     

Effect of nixtamalization process on the content and composition of phenolic compounds and antioxidant activity of two sorghums varieties

Sorghum, a competitive crop due to its agronomical advantages, has gained interest as functional food. Sorghum contains phytochemicals with health benefits and presents some antinutritional compounds such as condensed tannins (CTs). However, it is well known that CTs exhibit antioxidant capacity. This study evaluated the effect of Mexican nixtamalization on total phenols, CTs and antioxidant capacity using two varieties of sorghum. Different conditions of lime (0, 1 and 2%) and cooking time (20, 30 and 40 min) were tested to obtain the best treatment after optimization using multiple linear regression analysis, aiming to minimize the CTs content and maximize the antioxidant capacity. CTs were reduced at 27% in white sorghum and 90%, in red sorghum. Total phenols, flavonoids and antioxidant capacity had an inverse correlation with lime concentration and cooking time. The best conditions for preserving antioxidant capacity with low content of tannins were 1.13% of lime and 31.11 min cooking. The phenolic profile obtained by HPLC showed reductions in gallic and chlorogenic acids only in white sorghum, whereas catechin and quercetin decreased in both varieties. We concluded that nixtamalization effectively reduced CTs to safety intake values, allowing to preserve other phenolic compounds and antioxidant capacity.     

Research progress of vegetable oil and derivative in microbial fermentation for high-value-added metabolite production

Vegetable oil and derivative,as well as waste cooking oil,are important resources for microbial fermentation to produce high-value-added metabolites.Diversity of their compositions not only provides more choices for the fermentation by different microorganisms,but also is a challenge for their systematic utilization.According to the previous literature,4 main functions of vegetable oil and derivative can be summarized,such as carbon source,precursor,inducer and cell protectant during fermentation process.Currently,there is still insufficient knowledge about application of vegetable oil and derivative for high-value-added metabolite production.Therefore,this article firstly presented a comprehensive summary of compositions of vegetable oils and their derivatives,variety of corresponding microbial metabolites,limiting factors and optimization of fermentation process.     

油料作物中特异性脂类伴随物及其分析方法研究进展

油料作物作为植物油的主要来源,为人体生命活动提供了不可或缺的能量和营养素.油料作物中存在许多特异性脂类伴随物,如植物甾醇、植物多酚、角鲨烯、生育酚、白藜芦醇等,这些特异性成分不仅能影响油料作物的生理过程,也对食用油的品质产生重要的影响.本文对油料作物中主要的特异性脂类伴随物及其分析方法进行了综述,旨在为油料作物深加工产...     

大豆酶解制油蛋白酶的筛选及工艺条件的研究

在以大豆乳液为水解底物进行酶水解来提取大豆油的工艺中,应用蛋白酶水解细胞壁中的蛋白成分使得脂蛋白复合体中的油脂得以释放,从而提高油脂的得油率,通过研究选出破壁能力较强的蛋白酶并优化其水解条件,最后得到最佳水解工艺。