米糠油中谷维素的研究进展及在食品中的应用

对米糠油中谷维素的研究现状进行了综述,包括谷维素的定义、理化特性、生理功能、制备方法及国内外谷维素在食品领域的开发和应用。     

米糠深加工技术的分析与评价(Ⅱ) --米糠油精炼及其副产品的利用

米糠油是一种营养价值很高的植物油,但它含有较复杂的和数量较多的油溶性物质如游离脂肪酸、蜡质、色素等,大大增加了米糠油精炼难度,制约了米糠油的深度开发和利用.对几种典型米糠油精炼技术如化学精炼、物理精炼及混合油精炼、生物精炼、再酯化脱酸、膜技术脱酸等进行了介绍,并对其应用情况进行了评述;同时对米糠油副产品的利用技术如米糠油提取谷维素技术、植物甾醇的制取技术、天然维生素E的提取技术、糠蜡制取技术等作了较详细地论述和评价,以期为米糠油的综合开发利用提供参考.     

γ-Oryzanol, tocol and mineral compositions in different grain fractions of giant embryo rice mutants

BACKGROUND: Rice embryo is concentrated with lipid, protein and some bioactive chemicals. Two rice mutants IR64‐GE and TNG71‐GE (M7 generation) were characterised by an enlarged embryo compared with their wild types. In the present study, distributions of protein, lipid, total phenolics, γ‐oryzanol, tocols and some essential minerals in these two giant embryo mutants and their respective normal embryo wild types IR64 and TNG71 were compared. RESULTS: The embryo dry weights of giant embryo mutants IR64‐GE and TNG71‐GE were 0.92 and 1.32 mg per seed respectively. These values were higher than those of their respective normal embryo genotypes (0.50 and 0.62 mg per seed). Large variations in protein, lipid, phenolic, γ‐oryzanol, tocol and minerals levels were found between mutant and wild‐type pairs. The brown rice of TNG71‐GE had higher total γ‐oryzanol (average of 24% increase) and total tocol (average of 75% increase) levels than TNG71, IR64 and IR64‐GE. CONCLUSION: The embryo and bran parts of giant embryo mutant TNG71‐GE were found to be good sources of vitamin E and γ‐oryzanol. Therefore it could be used to produce high‐value by‐products from milled embryo and bran parts and as a genetic resource for rice improvement programmes. TNG71‐GE can also be used as a nutrient‐fortified rice cultivar. Copyright © 2011 Society of Chemical Industry     

米糠油萃取脱酸结合吸附脱酸工艺效果研究北大核心CSCD

为了在脱酸的同时尽可能保留米糠油中的营养成分,采用乙醇萃取脱酸结合碱性微晶纤维素吸附脱酸的低温物理脱酸技术对米糠油进行脱酸。以乙醇萃取脱酸米糠油为原料,以脱酸率为考察指标,采用单因素实验和正交实验对米糠油的吸附脱酸工艺条件进行了优化,同时对比了碱炼脱酸与乙醇萃取脱酸结合吸附脱酸对米糠油品质的影响。结果表明:最佳吸附脱酸工艺条件为碱性微晶纤维素添加量3.0%、吸附时间2.0 h、吸附温度40℃,在此条件下米糠原油经乙醇萃取脱酸结合吸附脱酸处理后,酸值(KOH)由35.04 mg/g降到0.92 mg/g,谷维素的保留率为73.0%,总甾醇保留率为74.3%,总生育酚保留率为56.5%;而米糠原油经碱炼脱酸处理后,酸值(KOH)由35.04 mg/g降到1.16 mg/g,谷维素的保留率为60.1%,总甾醇保留率为65.6%,总生育酚保留率为44.6%。可见,与传统碱炼脱酸相比,萃取脱酸结合吸附脱酸的方法对米糠油中谷维素、甾醇、生育酚的保留率更高,对游离脂肪酸的脱除效果更好。     

不同膨化条件对米糠主要营养成分影响的研究

挤压机瞬时、高温、高压、高剪切的加工特点使其具有生化反应器的功能。对不同膨化条件下米糠的主要营养成分变化情况进行研究。结果表明,杂交稻和优质稻米糠均可作为米糠相关食品的优质原料。膨化温度升高有利于米糠中粗脂肪、可溶性膳食纤维、谷维素含量升高;膨化温度为190℃,感官指标较好,谷维素含量为0.301%,可溶性膳食纤维含量为3.22%。膨化米糠酸价稳定性均表现较好。挤压后的米糠主要营养成分均发生了有益的变化,更利于人体的消化吸收和利用。     

Comparisons of protein, lipid, phenolics, γ-oryzanol, vitamin E, and mineral contents in bran layer of sodium azide-induced red rice mutants

BACKGROUND: The bran part of red rice grain is concentrated with many phytochemicals, including proanthocyanidins, oryzanol and vitamin E, that exert beneficial effects on human health, but it contains low levels of essential minerals such as Fe and Zn. In the present study, the protein, lipid, phytochemicals and mineral contents in bran samples were compared among red rice SA‐586 and its NaN₃‐induced mutants. RESULTS: The plant heights of NaN₃‐induced mutants were decreased. The contents of protein, lipid, total phenolics, total flavonoids, total anthocyanins, total proanthocyanidins, total γ‐oryzanol, total tocopherols and total tocotrienols also varied among the tested mutants. The brans of mutants M‐18, M‐56 and M‐50 contained more proanthocyanidins, γ‐oryzanol, vitamin E than that of SA‐586, respectively. M‐54 accumulated more Fe content (588.7 mg kg^?1 bran dry weight) than SA‐586 (100.1 mg kg^?1 bran dry weight). CONCLUSIONS: The brans of M‐18, M‐50 and M‐56 are good sources of proanthocyanidins, vitamin E and γ‐oryzanol, respectively, while the bran of M‐54 is rich in Fe. Thus these mutants could be used to produce high‐value phytochemicals or Fe byproducts from bran during rice grain milling or as genetic resources for rice improvement programs. Copyright © 2011 Society of Chemical Industry     

谷维素对纳米乳液理化稳定性的影响

研究了不同质量浓度谷维素(0%,1%,2%)及储藏温度(4,25,37℃)对纳米乳液理化稳定性的影响及其规律。结果表明:在不同储藏温度下,谷维素浓度对纳米乳液的物理稳定性没有显著影响。在4,25℃下,纳米乳液的化学稳定性与谷维素浓度不存在显著相关性。在37℃下,纳米乳液的过氧化值和茴香胺值与谷维素浓度呈负相关。根据动力学分析,一级动力学模型能更好反映纳米乳液中油脂氧化的变化趋势。     

高效保留米糠油营养成分的最佳吸附脱色条件研究

研究吸附脱色工艺条件(吸附剂种类、吸附剂用量、吸附脱色温度、吸附脱色时间)对米糠油吸附脱色综合效果(脱色率及谷维素、甾醇、维生素E等营养成分保留率和反式脂肪酸生成量)的影响。通过单因素试验和正交试验全概率分析得到最佳吸附脱色工艺条件:吸附脱色剂为活性白土,添加量为油重的3%,吸附脱色温度120℃,吸附脱色时间25 min。在此条件下得到脱色米糠油的色泽为Y20 R2.1(罗维朋比色槽25.4 mm),谷维素保留率为96.74%,甾醇保留率为90.60%,维生素E保留率为78.68%,反式脂肪酸未检出。脱色米糠油中营养成分得到了很好的保留。     

溶剂法萃取谷维素生产新工艺的研究

目前谷维素生产普遍采用碱溶酸析法生产工艺，谷维素得率为35％～40％。为了提高谷维素的得率和米糠油的精炼率，研究了溶剂法萃取生产谷维素新工艺。研究中测定了谷维素在甲醇等溶剂中于不同pH值中的溶解性能；物理精炼脱酸的工艺参数与谷维素热分解损失率的关系，并确定了逆流萃取的效数为2～3，萃取用甲醇的倍量为油重的1．5～3．5。溶剂法萃取使谷维素总得率在原有基础上提高到70％以上，谷维素纯度超过99％，达到了优质品标准；精炼米糠油产出率比碱溶酸析法提高了5％以上。同时，物理精炼脱酸工艺应用于高酸值米糠油的精炼，不产生碱炼皂脚，减轻了环境污染。     

米糠油谷维素提取方法研究进展

谷维素是从米糠油或胚芽油等谷物油脂中提取的一种天然混合物,是米糠油深加工过程中产生的极有价值的副产品。本文从谷维素的组成、提取和纯化方法进行综述,重点阐述不同提取工艺的特点和优缺点,分析实验中遇到的实际问题并且提出解决的办法。