微波预处理火麻籽对油的品质及抗氧化活性的影响

为考察微波预处理火麻籽(Cannabis sativa L.)对油的品质及抗氧化活性的影响,将火麻籽置于微波功率560W条件下预处理7min,冷却至室温后低温压榨制油。结果表明,微波预处理显著增加了油的酸价、过氧化值,降低了油的水分及挥发物含量,使油脂色泽变深,而脱壳处理可使色泽得到明显改善;火麻籽油中检出8种脂肪酸,其中油酸、亚油酸和亚麻酸是主要的脂肪酸,含量分别为13.88%、57.59%、16.33%,n-6/n-3脂肪酸为3.52∶1,是一种脂肪酸平衡合理的植物油;微波预处理不影响油的脂肪酸组成,使油中总酚含量增加1倍,总维生素E和植物甾醇含量分别增加41.99mg/kg和58.68mg/100g;微波预处理火麻籽显著改善了油的氧化稳定性,提高了油的抗氧化活性,与未经微波预处理的压榨火麻籽油相比,微波预处理后油的氧化诱导期延长了1.05h,DPPH自由基清除活力和FRAP总抗氧化能力分别增加8.46和81.85μmol/100g。表明微波预处理是一种适宜于提高火麻籽油品质的预处理方式。     

ω-3脂肪酸脱氢酶在高、低油大豆品种中的克隆与序列分析

α-亚麻酸（ALA）被称为必需脂肪酸,对人体有一系列的保健作用。ω-3脂肪酸脱氢酶（FAD）催化亚油酸（LA）生成ALA。大豆种子中ALA含量较高,为了比较高、低油大豆ω-3FAD的序列差异,用RT—PCR方法从大豆品种鲁豆11和郑9525的未成熟种子中扩增GmFAD3C的cDNA,获得的cDNA长度为1174bp,编码380个氨基酸。在推测的氨基酸序列中发现19处差异,为研究GmFAD3C基因在高、低油大豆种质中的差异表达奠定了基础。     

霍霍巴籽油化学组成的测定

采用气相色谱(GC)及色谱一质谱联用(GC/MS)法测定了霍霍巴籽油化学组成。证实福建东山岛沙滩生长的霍霍巴籽粒提取的油与一般植物油大不相同,其主要成分不是通常植物油中所含的脂肪酸甘油酯而是一元不饱和脂肪酸(主要是20碳—烯酸及22碳—烯酸)和一元不饱和脂肪醇(主要是20碳—烯醇和22碳—烯醇)组成的长链脂肪酸酯。     

Florisil固相萃取法联用气相色谱测定油脂中sn-2位脂肪酸

为探寻与气相色谱分析相配套的高效前处理方法,以测定不同物种来源的油脂中sn-2位(β位)脂肪酸组成及含量,考察了Florisil固相萃取柱对经sn-1,3专一性脂肪酶水解后的油脂各产物的分离富集能力,并对萃取条件进行了优化。结果表明,Florisil固相萃取柱能有效地将sn-2单甘脂从油脂水解产物中分离;同时发现Florisil固相萃取可以实现油脂水解产物中甘油三酯、甘油二酯、单甘脂及游离脂肪酸的依次分离。5种不同来源的油脂(植物油、藻油、微生物油脂、鱼油和海豹油脂),水解后经Florisil固相萃取柱萃取,联用气相色谱测定sn-2位脂肪酸组成及含量,结果表明,植物油、藻油和海豹油中sn-2位主要为中长链不饱和脂肪酸(植物油sn-2位中C18∶1,C18∶2和C18∶3约占95%;藻油sn-2位中C16∶1,C18∶1和C18∶2约占50%;海豹油sn-2位中C16∶1,C18∶1和C18∶2约占67%),菌油和鱼油中sn-2位多为长链多不饱和脂肪酸(菌油sn-2位中C20∶4约占37%;鱼油sn-2位中C20∶5,C22∶5和C22∶6约占40%)。     

油溶性茶多酚抗氧化作用的研究

本文比较了油溶性茶多酚、水溶性茶多酚、二丁基羟基甲苯(BHT)和丁基羟基茴香醚(BHA)在植物油中的抗氧化作用。并采用测色色差计比较这些抗氧化剂对植物油色泽和亮度的影响。同时,探讨了环境条件中光线和温度对油溶性茶多酚抗氧化性能的影响。     

云南大叶种茶树籽油的特征指标与脂肪酸组成研究

采用化学滴定及气相色谱等手段,对产自云南普洱的5个大叶种茶树籽油及8个常见食用植物油的特征指标(折光指数、相对密度、碘值、皂化值)和脂肪酸组成进行了对比研究.结果表明,5个大叶种茶树籽油折光指数为1.4629～1.4634;相对密度为0.9148～0.9167;碘值为859～903 g·kg-1;皂化值为189.0～1...     

H2S对盐碱混合胁迫下裸燕麦叶片脂肪酸组成的影响

脂肪酸是细胞膜脂的重要组成成分,信号分子硫化氢(H₂S)在植物响应盐碱胁迫中发挥着重要作用。为探讨H₂S对盐碱混合胁迫下裸燕麦脂肪酸组成的效应,采用盆栽砂培试验,研究了外施H₂S供体硫氢化钠(NaHS)和H₂S生成抑制剂羟胺(HA)对50 mmol·L^-1盐碱混合胁迫下裸燕麦品种定莜9号植株生长、叶片细胞膜脂氧化和脂肪酸组成的影响。结果表明：(1)喷施50μmol·L^-1 NaHS可显著缓解盐碱混合胁迫下定莜9号植株干重的下降和叶片超氧阴离子、过氧化氢和丙二醛含量的提高;增添HA后逆转了喷施NaHS缓解盐碱混合胁迫抑制定莜9号植株生长和叶片膜脂氧化损伤的作用。(2)盐碱混合胁迫导致定莜9号叶片50种脂肪酸中的部分组分含量发生显著改变,使总脂肪酸含量和脂肪酸不饱和程度显著降低。喷施50μmol·L^-1 NaHS使盐碱混合胁迫下定莜9号叶片5种脂肪酸组分棕榈酸(C16∶0)、岩芹酸(C18∶1N12)、异油酸(C18∶1N7)、亚油酸(C...     

追氮时期对冬小麦胚乳发育及灌浆特性的影响

为明确氮肥追施时期对冬小麦籽粒发育和灌浆特征的影响,选用冬小麦品种石麦18,采用随机区组设计,研究了LA1(春2叶期)、LA2(春3叶期)、LA3(春4叶期)、LA4(春5叶期)、LA5(春6叶期)5个追氮处理对籽粒胚乳细胞分裂增殖和灌浆特征的影响。结果表明,追氮时期对胚乳细胞增殖和灌浆特征均有显著影响。LA1、LA2和LA3处理的胚乳细胞在籽粒建成期分裂速率较高,而后分裂速率急剧下降,胚乳细胞数较少;灌浆速率表现为前期较高,后期较低;成熟时粒重较低。LA4处理能延长籽粒胚乳细胞增殖活跃期,在花后21 d后胚乳细胞仍然具有较高的分裂增殖能力,胚乳细胞数目最多,籽粒的最大灌浆速率最高,后期的灌浆能力较强,粒重最高。LA5处理胚乳细胞数较多,后期灌浆速率较低,粒重仅低于LA4处理。     

大豆种子脂肪酸组分的研究进展

随着社会的进步和人们生活水平的提高,人们越来越重视自身的健康状况.大豆油的饱和脂肪酸与不饱和脂肪酸的比例相对其它的植物油(如菜籽油、花生油等)较为合理,其消费量和食用量也已经逐步超过了其它植物油,成为人们日常饮食重要的营养来源之一.本文在脂肪酸组成、脂肪酸组分形成与地理纬度、气象因素的关系、及发育种子脂肪酸组分的形成等方面综述了大豆种子脂肪酸组分的研究进展,并指出了该领域目前存在的主要问题和发展的前景.     

气相色谱方法定量检测大豆5种脂肪酸

为建立大豆脂肪酸组分的绝对定量方法,采用加热甲酯化提取法和气相色谱分析法(GC),以5种脂肪酸甲酯(棕榈酸甲酯、硬脂酸甲酯、油酸甲酯、亚油酸甲酯和亚麻酸甲酯)为标准样品,在制定5种脂肪酸甲酯组分的标准曲线(R20.99)和回归方程的基础上,建立了大豆脂肪酸组分的定量测定方法。该方法可以准确检测大豆籽粒中脂肪酸组分的绝对含量。通过对4个油份含量不同的大豆品种脂肪酸含量测定以及与粗脂肪含量的比较分析发现,该方法可显著提高籽粒中的脂肪酸提取率和检测效率,其检测的总脂肪酸含量占总油脂含量的94%以上。该方法不仅能检测样品中5种脂肪酸组分的相对百分比含量,还可以准确计算出籽粒中各个脂肪酸组分的绝对含量,对大豆脂肪酸检测及育种具有重要意义。     

油棕的综合利用

叙述了油棕的主要产品棕榈油在餐饮业、食品制造业和工业上的应用,以及油棕副产品、油棕树的树叶、树干等的利用状态,并对油棕的综合利用进行了展望。     

Comparison of palm and mixtures of refined palm and soybean oils on serum lipids and fecal fat and fatty acid excretions of adult humans

The effects of palm (P) and mixtures of palmand soybean (PS), palmolein and soybean (POS),palmstearin and soybean (PSS) oils on serum lipids andfecal fat and fatty acid excretions of humans werestudied. Each oil was the dominant fat in dietsconsumed by ten normolipidemic live-in individuals.Test diets were assigned by randomization. All fourdiets had a similar influence on total cholesterol (TC),low density lipoprotein (LDL), high densitylipoprotein (HDL), very low density lipoprotein(VLDL), triglycerides (TG) and phospholipids (PL). Fecalfat excretion was higher (1.81, 1.80 g/d) with PS andPSS and lower (1.78, 1.42 g/d) with P and POS diets.Excretions of palmitic (C16: 0), oleic (C18: 1), andlinoleic (C18: 2) acids were similar for all diets.Excretions of stearic acid (C18: 0) were higher whenfeeding POS and PSS, and lower with feeding P and PS;the changes were statistically significant atp < 0.05. More linolenic acid (C18: 3) was excretedwhen P was fed compared to the feeding of PS, POS, andPSS. Changes in linolenic acid excretion between P andPOS were statistically significant at p < 0.05. It wasconcluded that there were no significant differencesin serum lipid concentrations due to feeding palm orany of the refined palm and soybean oil mixtures.However, a significant difference was found in C18: 0excretions with feeding POS and PSS compared to whenP and PS were fed. Similarly, significant C18: 3excretion was found with feeding P compared to whenPOS was fed.     

响应面法优化6^#溶剂油提取亚麻籽油工艺研究

利用响应面法对6#溶剂油提取亚麻籽油的工艺进行优化,分别对料液比、反应温度、反应时间、浸泡时间进行分析．建立二次多项式回归方程预测模型。结果表明：最佳工艺条件为料液比1：16g／mL、反应温度90℃、反应时间6h、浸泡时间38h。与超临界CO2萃取法相比,本方法生产成本大大降低,同时出油率提高0．5％     

Lipids and Tocopherols in Serum and Liver of Female Rats Fed Diets Containing Corn Oil or Cottonseed Oil

Growing female rats were fed diets containing either corn oil (CO) or cottonseed oil (CSO) to determine if the previously reported lowering effect of CSO versus CO on serum total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-C) was sex specific and to compare the effect of these two oils on serum and tissue concentrations of RRR-alpha-tocopherol (α-T) and RRR-gamma-tocopherol (γ-T), the two major tocopherols in these oils. In a 4-week study, groups of rats (n=10 each) were fed diets containing 100 g/kg of either CO or CSO. TC was lower for group CSO than group CO. Serum concentrations of HDL-C, non-HDL-C, triglycerides (TGs), as well as the TC/ HDL-C ratio and the hepatic concentrations of cholesterol and TGs, were unaffected by diet. For serum and liver, between-group differences were noted for the concentrations of α-T (where values were higher for group CSO) and γ-T (where values were lower for group CSO). These differences reflected differences between the oils in their concentrations of these tocopherols. Thus, CSO has a lowering effect on TC for both sexes, but on HDL-C for male animals only; replacement of CO with CSO results in changes in tocopherol status.     

不同收获时间对白千层油质量及产油率的影响

从白千层收割后第6个月开始取样至第18个月止,采用水蒸气蒸馏法提取白千层油,应用气相色谱-质谱联用仪分析白千层油化合组分。结果表明∶在湛江地区种植6a后的白千层油各项质量指标均达到国际标准水平。在1a中的不同收获时间内,白千层油的主要质量指标——松油烯醇-4、校叶油素和产油率均有较大变化     

Effect of DHA Containing Oils and Powders on Baking Performance and Quality of White Pan Bread

Different sources of DHA and/or n-3 (omega-3) rich oils, oil emulsions and microencapsulated (ME) powders were tested at two different concentrations with the aim of producing fortified pan bread. Three oils (S-algae, fish and flax), two emulsified algae oils (Emulsion-P and Emulsion-L) and two ME oils (ME-S algae and ME-C algae) were compared. The DHA and n-3 oils replaced part of the shortening in order to obtain 32 g slices enriched with 25 or 50 mg DHA, 35 or 70 mg total n-3 from fish oil and 90 or 180 mg linolenic from flax oil. Addition of oils did not significantly affect water absorption but reduced mix time whereas addition of the ME oils decreased both water absorption and mix time. Breads enriched with flax or ME-C oils had lower volume and higher density than the control, ME-S algae, Emulsion-P and Emulsion-L breads. All breads lost texture throughout 14 d storage, the major changes occurred after 3 d. The ME-S algae oil bread had the best softness after 14 d storage whereas breads produced from ME-S algae or ME-C algae oils had the poorest texture. Sensory evaluations indicated that the color of the ME-S algae oil fortified bread was significantly less preferred than the other loaves. After 6 d the control bread had higher acceptability compared with the rest of the breads enriched with high levels of DHA or omega-3 oils. The high-enriched fish oil bread was well accepted during the first days of storage but had the least preferred acceptability after 13 d. The best fortified breads were those supplemented with S-algae oil, Emulsion-P and Emulsion-L oils.     

响应面试验优化大豆油甲酯合成工艺

以大豆油和甲醇为原料,KOH为催化剂,采用响应面法对大豆油甲酯合成工艺进行优化。在单因素试验的基础上,以反应物醇油摩尔比、催化剂用量、反应温度、反应时间为影响因素,大豆油甲酯的产率为响应值,进行响应面分析。结果表明大豆油甲酯的最佳合成条件为:醇油摩尔比为5.5∶1,催化剂用量为大豆油质量的1.08%,反应温度为61.6℃,反应时间为60 min。此条件下大豆油甲酯的产率为94.02%,与模型预测值基本一致。大豆油甲酯的一些性能接近矿物油,以其部分或全部取代矿物油制备环保型大豆油墨具有极大的潜力。     

Fatty Acid Composition of Serum,Adipose Tissue,and Liver in Rats Fed Diets Containing Corn Oil or Cottonseed Oil

There have been few studies on the effect of cottonseed oil (CSO), one of the most commonly used vegetable oils in the United States, on indices of lipid status either in the rat or in any other species. Previous studies with rats have focused on the effect of CSO, versus that of other vegetable oils, on the concentration of cholesterol in serum and liver or on a limited number of fatty acids in serum, adipose tissue, or liver. The present study was designed to compare more fully than in previous studies the effect of CSO to that of corn oil (CO) on the fatty acid composition of serum, adipose tissue, and liver. Two groups of male rats (n=10 each) were used, each fed one of two purified diets containing 100 g/kg of either CO or CSO. Between-group differences included higher values (mol% total fatty acids) in adipose tissue for palmitic acid and stearic acid, but lower values in serum, adipose tissue, and liver for cis-vaccenic acid and oleic acid (C18:1n-9) for the CSO group than the CO. In addition, values in serum, adipose tissue, and liver for -linolenic acid (C18:3n-3) and its metabolite, docosahexaenoic acid (C22:6n-3), were lower for the CSO group than the CO. There was no effect of diet on serum or tissue levels of n-6 fatty acids (linoleic acid, dihomo--linolenic acid, and arachidonic acid). Differences in fatty acid compositions noted, e.g., those for C18:1n-9 and C22:6n-3, mainly reflected compositional differences between the two oils. Thus, use of CSO rather than CO affected serum and tissue concentrations of saturated, monounsaturated, and n-3 polyunsaturated fatty acids (PUFAs) but had no effect on n-6 PUFA status.     

Yeast breads containing oils varied in fatty acid composition: Effects on sensory panel acceptability

Choice of the shortening ingredient in bread products has functionality effects and health implications. Little information is available on effects of various shortening ingredients on palatability and acceptability. The objective of the current study was to compare the acceptability of yeast-leavened wheat breads containing shortenings containing predominantly saturated fatty acids (coconut oil), monounsaturated fatty acids (canola oil) or unsaturated fatty acids (unhydrogenated soybean oil). Breads were prepared using a standardized formula and method. These were evaluated by a 16-member, semi-trained panel for color, flavor, texture, tenderness and overall acceptability using a seven-point hedonic scale. No significant differences in color and texture were defined; however, canola oil bread was judged significantly superior to soybean oil bread in flavor, and both of these breads were found to be significantly superior to coconut oil bread in flavor, tenderness, and overall acceptability.     

Serum and liver lipids in rats fed diets containing corn oil,cottonseed oil,or a mixture of corn and cottonseed oils

Previous research has demonstrated that the total replacement of corn oil (CO) with cottonseed oil (CSO) in the diets of growing male rats results in a lowering of the total cholesterol (TC) concentration in the serum. It is not, however, known if a partial replacement of dietary CO with CSO would be sufficient to lower TC levels, nor is the effect of replacing dietary CO with CSO on other indices of cholesterol status (e.g., the levels of high-density lipoprotein cholesterol [HDL-C], non-HDL-C [i.e., very-low and low-density lipoprotein-cholesterol], or the TC/HDL-C ratio). Growing male rats were fed diets having CO, CSO, or a CO/CSO (1:1, w/w) oil mixture (OM) as the source of dietary oil (diet groups CO, CSO, and OM, respectively). There were no differences between CO and OM groups for TC, HDL-C, non-HDL-C, or the TC/HDL-C ratio. However, TC was significantly lower (p 0.05)for the CSO group than the CO group (2.85 vs. 3.23 mmol/l, or 110 vs. 125 mg/dl, respectively) as was HDL-C (1.83 vs. 2.13 mmol/l, or 71 vs. 82 mg/dl, respectively), but there were no differences between these groups for non-HDL-C or the TC/HDL-C ratio. Diet had no effect on serum triglycerides (TGs) or on total liver content of either cholesterol or TGs. Thus, partial (50%) replacement of CO with CSO was without effect on any of these serum indices of cholesterol status, but total replacement resulted in lower TC and HDL-C, without affecting non-HDL-C or the TC/HDL-C ratio. Because, relative to CO, CSO has higher levels of saturated fatty acids but lower levels of monounsaturated and polyunsaturated fatty acids, the cholesterol-lowering effect of CSO appears to be unrelated to its fatty acid composition, and may be caused by a component of its nonsaponifiable fraction.