Quality traits and lipid composition of meat from Nellore young bulls fed with different oils either protected or unprotected from rumen degradation

The qualitative characteristics, lipids and chemical composition of the meat of 35 Nellore young bulls were analyzed. These bulls had an average slaughter weight and fat thickness of 532.17 ± 30.2 kg, and 7.00 mm, respectively. Significant differences were found only in the meat's water holding capacity (WHC), which was higher for animals fed with fresh linseed oil. More conjugated linoleic acid (CLA) was found in the meat of animals fed with unprotected soybean oil, while better omega-6/omega-3 ratios were noted for those fed unprotected linseed oil. The addition of different vegetable oils to the bulls' diet (soybean or linseed, either protected or not protected from rumen digestion) did not interfere with the qualitative characteristics of their meat while improving the lipid composition of the longissimus muscle. Of the oils examined, unprotected linseed oil most improved the omega-6/omega-3 ratio, thus producing the healthiest meat for human consumption.     

Dietary omega‐3 PUFA and health: Stearidonic acid‐containing seed oils as effective and sustainable alternatives to traditional marine oils

The daily consumption of dietary omega‐3 PUFA is recommended by governmental agencies in several countries and by a number of health organizations. The molecular mechanisms by which these dietary PUFA affect health involve the enrichment of cellular membranes with long‐chain 20‐ and 22‐carbon omega‐3 PUFA that impacts tissues by altering membrane protein functions, cell signaling, and gene expression profiles. These changes are recognized to have health benefits in humans, especially relating to cardiovascular outcomes. Cellular membrane enrichment and health benefits are associated with the consumption of long‐chain omega‐3 PUFA found in marine oils, but are not generally linked with the consumption of alpha‐linolenic acid, the 18‐carbon omega‐3 PUFA found in plant seed oils. However, the supply of omega‐3 PUFA from marine sources is limited and may not be sustainable. New plant‐derived sources of omega‐3 PUFA like stearidonic acid‐soy oil from genetically modified soybeans and Ahiflower oil from Buglossoides arvensis seeds that are enriched in the 18‐carbon omega‐3 PUFA stearidonic acid are being developed and show promise to become effective as well as sustainable sources of omega‐3 PUFA. An example of changes in tissue lipid profiles associated with the consumption of Ahiflower oil is presented in a mouse feeding study.     

Persistent Organic Pollutants in Fish Oil Supplements on the Canadian Market: Polychlorinated Dibenzo-p-Dioxins, Dibenzofurans, and Polybrominated Diphenyl Ethers

ABSTRACT:  Canadians are interested in improving their diet through the consumption of fish oil food supplements, which are marketed to be rich in omega-3 fatty acids. Convenience samples of omega-3 enriched dietary supplements ( n  = 30) were collected in Vancouver, Canada, between 2005 and 2007. All of the omega-3 supplements were analyzed for polychlorinated dibenzo- p -dioxins/furans (PCDD/Fs) and polybrominated diphenyl ethers (PBDEs) and, although every sample was found to contain detectable residues of PBDEs, only 24 samples were found to have PCDD/F concentrations above the level of detection. PCDD/F concentrations ranged from 0.05 pg TEQ/g lipid to 45.7 pg TEQ/g lipid in salmon and shark oils, respectively. Maximum PBDE concentrations similarly were observed in shark oil (113 μg/kg lipid), however, most supplements had concentrations below 5 μg/kg lipid. Average PCDD/F and PBDE intake estimates, based on consumption of maximum supplement dose following product label recommendations, were 4.32 pg TEQ/d and 25.1 ng/d lipid, respectively.     

Encapsulation of vegetable oils as source of omega-3 fatty acids for enriched functional foods

Polyunsaturated omega-3 fatty acids (PUFAs), a functional component present in vegetable oils, are generally recognized as being beneficial to health. Omega-3 PUFAs are rich in double bonds and unsaturated in nature; this attribute makes them highly susceptible to lipid oxidation and unfit for incorporation into long shelf life foods. The microencapsulation of oils in a polymeric matrix (mainly polysaccharides) offers the possibility of controlled release of the lipophilic functional ingredient and can be useful for the supplementation of foods with PUFAs. The present paper provides a literature review of different vegetable sources of omega-3 fatty acids, the functional effects of omega-3 fatty acids, different microencapsulation methods that can possibly be used for the encapsulation of oils, the properties of vegetable oil microcapsules, the effect of encapsulation on oxidation stability and fatty acid composition of vegetable oils, and the incorporation of long-chain omega-3 polyunsaturated fatty acids in foods.     

Effects of dietary sources of vegetable oils on performance of high-yielding lactating cows and conjugated linoleic acids in milk

This study was conducted to examine the effects of dietary supplementation with vegetable oils on performance of high-yielding lactating cows and conjugated linoleic acid (CLA) content in milk fat. Twelve lactating Holstein cows in early lactation (30 to 45 d postpartum) were used in a triple 4 × 4 Latin square design. In each period, the cows in each group were fed the same basal diet and received one of the following treatments: 1) control (without oil), 2) 500 g of cottonseed oil, 3) 500 g of soybean oil, and 4) 500 g of corn oil. Each experimental period lasted for 3 wk, with the first 2 wk used for adaptation to the diet. Supplementation with vegetable oils tended to increase milk yield, with the highest milk yield in the cottonseed oil group (35.0 kg/d), compared with the control (34.4 kg/d). Milk fat percentage was decreased, but there were few effects on percentage and yield of milk protein as well as milk fat yield. The cows fed added soybean oil produced milk with the highest content of trans-11 C_18:1 (23.8 mg/g of fat), which was twice that of the control (12.6 mg/g of fat). Content of cis-9, trans-11 CLA in milk fat increased from 3.5 mg/g in the control to 6.0, 7.1, and 10.3 mg/g for the cows fed oils from cottonseed, corn, and soybean, respectively. A significant linear relationship existed between trans-11 C_18:1 and cis-9, trans-11 CLA. Supplementation with oils doubled the content of total fatty acids in blood plasma, with little difference between different vegetable oil sources. Octadecenoic acid content was significantly higher in blood plasma of animals fed added oils from cottonseed and soybean than those fed with corn oil and control. The plasma trans-11 C_18:1 content was significantly higher in the oil-added animals than in control. Supplementation of vegetable oils tended to improve milk production of lactating cows, and the CLA content in milk fat was significantly increased. Soybean oil seemed to be the optimal source to increase CLA production.     

Effects of deep frying vegetable oils rich in PUFAs on gut microbiota in rats

Vegetable oils rich in PUFAs are widely used in daily cooking and food industry, and PUFAs could be utilised by gut microbiota and present prebiotic effects. However, PUFAs are unstable in high-temperature cooking like frying. In the current study, we aimed to explore the influence of thermally oxidised oils rich in PUFA on gut microbiota. Two vegetable oils: omega-3 alpha-linolenic acid (ALA)-rich perilla oil or omega-6 linoleic acid-rich sunflower oil were heated at 180 °C for 10 h, and then fed to male SD rats for 14 weeks. Administration of heated perilla oil dramatically increased the relative abundance of Akkermansia muciniphila, a recent identified probiotics which may weaken intestinal mucus barrier, and inhibited the expression of several tight junction-related genes including occludin and claudin-1 in colon. Consumption of thermally oxidised sunflower oil stimulated the proliferation of Bifidobacterium. Our findings suggested that thermally processing has complicated effects on the prebiotic effects of vegetable oils rich in PUFAs, and perilla oil fried foods may be potential sources to stimulate Akkermansia proliferation in gut.     

食用植物油中反式脂肪酸的暴露评估

采用气相色谱法检测我国居民常用食用植物油中反式脂肪酸的含量,运用Crystal Ball软件对食用植物油样品中反式脂肪酸的暴露水平和暴露影响因子的敏感性进行分析,结果显示反式脂肪酸日均暴露量的平均值为1.81E-4kg/d;食用植物油中反式脂肪酸含量的敏感性最强,占99.3%,拉平时间为负值,表明它对反式脂肪酸日均暴露量起负面的影响。     

计算机辅助营养均衡菜籽调和油的研制

以菜籽油为基质油,通过计算机辅助计算,采用其他植物油调节ω-3与ω-6脂肪酸比例,研制出营养均衡菜籽调和油。以氧化诱导时间为指标,考察营养均衡菜籽调和油的氧化稳定性,并与原料植物油进行比较,通过动物实验研究其辅助降血脂功效。实验结果表明,营养均衡菜籽调和油中ω-3脂肪酸与ω-6脂肪酸的质量分数比例约为1∶3.05,饱和脂肪酸、单不饱和脂肪酸和多不饱和脂肪酸质量分数比例为0.28∶1.0∶1.0,更符合人体对脂肪酸均衡摄入的要求;110 ℃时调和油的氧化诱导时间为4.5 h,辅以少量抗氧化剂特丁基对苯二酚（tertiarybutylhydroquinone,TBHQ）后延长到6.0 h,满足油脂氧化稳定性要求;辅助降低实验性高血脂大鼠甘油三酯功能结果呈现阳性。     

Oxidative Stability of Cooking Oil Blend Stabilized with Leaf Extract of Eucalyptus citriodora

The present study was conducted to assess the effects of Eucalyptus citriodora (E. citriodora) leaf extract on the oxidative stability of blend of canola, rapeseed, and sunflower oils (45:20:35 v/v, respectively) under accelerated storage. The blended oil was stabilized with 300 mg/L ethanolic extract (source of total phenolic content and total flavonoid content [5.23 ± 0.19 and 1.18 ± 0.04 g/100 g d.wt. of extract]) of E. citriodora leaves. The oxidative stability was measured on the basis of parameters such as free fatty acid contents, peroxide value, sponification value, iodine value, color, cloud point, and refractive index. After a 100 day incubation period, the increase in refractive index, free fatty acid, and peroxide, and sponification values in stabilized and non-stabilized oil blends were 0.0028 and 0.0047, 0.20 and 2.37% as oleic acid, 12.54 and 21.12 meq/kg of oil and 10.04 and 17.01 meq of KOH/g of oil, respectively, as compared with initial values. However, a decrease of 10.0 and 16.9 g of iodine/100 g of oil was recorded in oil iodine values of both stabilized and non-stabilized blended vegetable oils. Results showed that E. citriodora leaf extract was found effective to maintain the oxidative stability of blended vegetable oils for long duration (6 months) as compared with control oil samples. Therefore, it can be concluded that E. citriodora leaf extract is a cheap rich source of natural antioxidants that can be easily used for the stabilization of vegetable oils in the food processing industries.     

脂肪酸含量对植物油介电特性的影响

为了提供植物油在微波和射频等介电加热技术和通电加热技术中的应用基础数据,考察脂肪酸含量对植物油介电特性的影响,分别利用LCR阻抗测试仪和网络分析仪(同轴探针法)测量了4种植物油(橄榄油、自制橄榄油、橄榄调和油、大豆油)和5种脂肪酸(棕榈酸、硬脂酸、油酸、亚油酸、亚麻酸)在低频段(1 000 Hz~2 MHz)和高频段(300~10 000 MHz)的介电特性。结果表明:低频下,植物油的介电常数比较稳定,其均值为(1.56±0.02),介电损耗随着频率的增加而下降,其中0.7 MHz时橄榄油具有最大的介电常数(1.67±0.00)和介电损耗(7.31±0.02);高频下,植物油的介电特性随着频率的上升而缓慢下降,4种植物油之间的介电特性的差异不显著(p0.05);低频下,在植物油中加入油酸后,植物油的介电常数和介电损耗呈现先上升后下降的趋势,而添加亚油酸呈现相反的趋势。添加脂肪酸会加快油脂的氧化反应。     

Fatty Acid Composition Including Trans‐Fatty Acids in Edible Oils and Fats: Probable Intake in Indian Population

Abstract: The susceptibility of trans‐fat to the human health risk prompted the Food and Agriculture Organization (FAO) and World Health Organization (WHO) to prepare regulations or compulsory claims for trans‐fatty acids (TFA) in edible oils and fats. In this study, analysis of fatty acid composition and TFA content in edible oils and fats along with the possible intake of trans‐fat in Indian population was carried out. The analysis was carried out as per the Assn. of Official Analytical Chemists (AOAC) methodology and the results were statistically analyzed. The average TFA content in nonrefined mustard and refined soybean oils exceeded by 1.16‐ to 1.64‐fold as compared to the Denmark limit of 2% TFA in fats and oils destined for human consumption. In branded/nonbranded butter and butter oil samples, average TFA limit exceeded by 4.2‐ to 9.5‐fold whereas hydrogenated vegetable oil (HVO) samples exceeded the limit by 9.8‐fold, when compared to Denmark standards. The probable TFA intake per day through different oils in Indian population were found to be less than WHO recommendation. However Punjab having highest consumption of HVO (–15 g/d) showed 1.09‐fold higher TFA intake than the WHO recommendation, which is alarming and may be one of the factors for high cardiovascular disease mortality rate that needs further elucidation. Thus there is a need to prescribe TFA limit for edible oil, butter, and butter oil in India and to reduce the already proposed TFA levels in HVO to safeguard the health of consumers. Practical Application: The probable daily intake of trans‐fatty acid (TFA) especially through hydrogenated vegetable oil (HVO) was assessed. In absence of any specification for TFA and fatty acid composition for edible oils, butter, and butter samples, a pressing need was felt to prescribe TFA limit in India. The study indicates that TFA intake through HVO consumption is higher in States like Punjab than the recommended daily intake prescribed by WHO. Hence, strategies should be adopted to either decrease the consumption of HVO or to modify the industrial processing method of HVO with less content of TFA to safeguard the health of consumers.     

大豆油食用期氧化稳定性的研究

以过氧化值、酸值和p-茴香胺值为评价指标,模拟大豆油家庭食用条件,研究充氮气、添加抗氧化剂(TBHQ)的大豆油(2.5L/桶)在3个月(6、7、8月)食用期内的品质变化规律.结果表明:在3个月的食用期内,2种处理方式下大豆油的过氧化值、酸值和p-茴香胺值均随着时间的延长逐渐增加,其中,过氧化值分别在第70、50 d达到质量安全值5.0 mmol/kg,酸值均小于质量安全值0.2 mg KOH/g,p-茴香胺值变化不大.与添加抗氧化剂相比,氮气储藏同样提高了大豆油的稳定性,氮气储藏可以成为大豆油的一种绿色储藏方法.     

Efficacy of essential oil of Ocimum basilicum L. and O. gratissimum L. applied as an insecticidal fumigant and powder to control Callosobruchus maculatus (Fab.) [Coleoptera: Bruchidae]

Essential oils from sweet basil, Ocimum basilicum, and African basil, O. gratissimum, (Labiatae) grown in Guinea were obtained by steam distillation. Following exposure of newly emerged adult beetles (Callosobruchus maculatus) to 12 h of fumigation using pure essential oils at a dose of 25 μl/vial, 80% mortality was recorded for O. basilicum, 70% for O. gratissimum and 0% in the control. A significant difference was observed between the responses of males and females with males exhibiting greater sensitivity. When 1 g of aromatized powder was applied to adults, a 50% lethal concentration at 48 h was found to be 65 μl/g for O. basilicum and 116 μl/g of O. gratissimum oils. The essential oils from the two plant species exhibited a significant effect both on the egg hatch rate and on the emergence of adults. The egg hatch rate was reduced to 3% with O. basilicum and 15% with O. gratissimum using an essential oil concentration of 30 μl, whereas the egg hatch rate for the control was 95%. When compared with the control (97%), adult emergence dropped to 0% with O. basilicum and to 4% with O. gratissimum. Storage bioassays were run to assess the long-term effect of powders aromatized with essential oils of Ocimum. Complete protection was observed over 3 months starting at a dose of 400 μl in the case of both oils. From a germination test, it was concluded that aromatized powders have no significant effect on the seed germination rate. After 5 d, a rate of 88% germination was seen in seeds treated with aromatized powder and protected from insects, compared with 97% for untreated seeds that were not exposed to insects.     

基于植物油中脂肪酸烷基酯含量变化鉴别废弃油脂

采用固相萃取柱净化,气相色谱-质谱联用法测定了6种植物油中脂肪酸烷基酯(包括脂肪酸甲酯和脂肪酸乙酯)的含量,并研究其在植物油煎炸、废弃及废弃油脂精炼等环节中的变化。结果发现,6种植物油中脂肪酸烷基酯的含量均低于30 mg/kg,而植物油在废弃过程中可能会形成大量脂肪酸乙酯,生成量与油脂是否烹饪及废弃物中乙醇含量有关。脂肪酸烷基酯在脱色工艺中不能被去除,但在脱臭中可被去除。因此,可以通过测定植物油中脂肪酸烷基酯含量发现废弃油脂,为废弃油脂的鉴别工作提供新的思路。     

荤素分类煎炸对油脂品质的影响

为了延长煎炸油的使用寿命,有效降低成本,研究了荤素分类煎炸对油脂品质的影响。采用食材荤素分类及不分类煎炸并循环使用煎炸油,分析了两种煎炸方式下煎炸油的色泽、酸值、过氧化值、p-茴香胺值、极性组分含量的变化情况,并对比分析两种煎炸方式用油量。结果表明：采用荤素分类煎炸可以更好地抑制油脂色泽、酸值、p-茴香胺值及极性组分含量的增长速度;不分类煎炸油脂的色泽在煎炸2 d后无法用比色仪检测,分类煎炸7 d后油脂的色泽才接近不分类煎炸2 d的色泽;不分类煎炸的油脂酸值(KOH)在煎炸前3 d内急剧上升,由初始的0.09 mg/g增至1.30 mg/g,分类煎炸的油脂酸值(KOH)浮动较小,由初始的0.09 mg/g最高增加至0.62 mg/g;在煎炸7 d时,不分类煎炸的油脂p-茴香胺值由初始的4.0增加到38.0,分类煎炸的油脂p-茴香胺值由初始的4.0增加到15.0,不分类煎炸油脂的p-茴香胺值的增长速度是分类煎炸的近3倍;不分类煎炸,油脂极性组分含量在第1天内急剧上升,在第4天达到最高,为12.5%,后逐渐趋于平稳,分类煎炸,油脂极性组分含量在前3 d内均保持在8%左右,之后才有上升的趋势...     

美藤果油和普洱茶籽油的主要脂肪酸组成及氧化动力学研究

采用气相色谱-质谱法测定美藤果油和普洱茶籽油的主要脂肪酸组成,并利用热重分析法(thermogravimetric analysis,TGA)测定不同升温速率下两种植物油的起始氧化温度(Ton)和氧化峰值温度(Tp),并对两种植物油的动力学参数进行求解。结果表明:美藤果油和普洱茶籽油的不饱和脂肪酸含量分别为92.89%、79.08%;随着升温速率的增加,两种植物油的Ton和Tp均随之升高。由热重分析法计算出在Ton处的活化能分别为:美藤果油123.5 kJ/mol;普洱茶籽油125.7 kJ/mol。美藤果油在Tp处的活化能是150.9 kJ/mol,普洱茶籽油是127.6 kJ/mol。总体来看,两种植物油都具有很好的热稳定性。     

焙炒处理对不同植物油品质特性的影响北大核心CSCD

为了研究焙炒对植物油品质的影响,以油菜籽、亚麻籽、花生、葵花籽和芝麻为原料,经焙炒处理后采用液压压榨法制油(热榨油),分析植物油的理化指标(酸值、过氧化值、水分及挥发物、色泽)、主体组分(脂肪酸组成及含量、甘三酯组成及含量、挥发性组分)和总酚含量,并与未焙炒处理直接压榨制取的油(冷榨油)作对比。结果表明:热榨油酸值和过氧化值显著高于冷榨油(p<0.05),其中,热榨亚麻籽油酸值(KOH)最高(0.96 mg/g),热榨菜籽油过氧化值最高(1.02 mmol/kg);冷榨油水分及挥发物含量显著高于热榨油(p<0.05),其中冷榨花生油水分及挥发物含量最高(0.16%);热榨油的色泽较冷榨油深,其中热榨菜籽油的色泽最深(R1.1,Y31);焙炒对植物油脂肪酸和甘三酯组成及含量无显著影响(p>0.05);热榨油中醇类、醛类和酸类等挥发性组分较少,但杂环类物质较多;热榨菜籽油、亚麻籽油、花生油、葵花籽油和芝麻油总酚含量分别是其冷榨油的1.38、1.57、1.51、1.80倍和1.27倍。因此,焙炒对植物油品质影响较大,应根据生产需要选择合适的预处理方式。     

拉曼光谱法快速鉴别劣质火锅油

长期食用劣质火锅油会对人体产生严重伤害。为快速鉴别劣质火锅油,对火锅油和6种普通的食用植物油进行拉曼光谱测试分析。结果表明：火锅油的拉曼光谱在1 150 cm-1和1 525 cm-1处有明显的谱峰,而其他食用植物油则没有,利用主成分分析法可以明显地区别火锅油和普通食用植物油;对同一种火锅油经过反复熬煮和存放,其拉曼光谱在1 525 cm-1谱峰处的相对强度与酸值具有较高的相关性,相关系数达到0.925 6。拉曼光谱法可以作为一种现场快速鉴别火锅油与食用植物油以及检测火锅油质量的潜在方法。     

近红外光谱快速检测食用植物油中酸价

目的 建立基于近红外光谱快速测定食用植物油中酸价的分析方法。方法 采用冷溶剂指示剂滴定法检测371个食用植物油样品的酸价,并采集样品的近红外光谱。经过标准正态变换结合一阶导数对近红外光谱进行数据预处理,选用竞争性自适应重加权采样算法选取重要变量,建立食用植物油酸价的偏最小二乘回归模型。结果 蒙特卡洛交互验证结果显示,食用植物油酸价预测模型的验证集决定系数Q2为0.9983,交互检验的均方根误差(root mean square error of cross validation, RMSECV)为0.0461,模型预测的独立测试集的酸价与实测值相关系数为0.9834,预测效果良好。结论 本研究建立的食用植物油酸价近红外光谱快速检测方法能够满足检测要求,为评价或跟踪食用油品质提供快速无损的技术思路。     

Children's daily exposure to polychlorinated biphenyls from dietary supplements containing fish oils

In children, omega-3 polyunsaturated fatty acids (PUFAs) may elicit a suite of health benefits including enhancement of cognitive development. Subsequently, dietary supplements containing omega-3 PUFAs have become increasingly popular. Often, the largest source of beneficial PUFAs in these supplements is fish oil, which may contain significant levels of contaminants such as polychlorinated biphenyls (PCBs). The objectives of this study were to evaluate congener-specific PCB concentrations in 13 over-the-counter children's dietary supplements containing fish oils/powders and assess potential PCB exposures through ingestion of these products on a daily basis. Every supplement analysed contained PCBs, with a mean concentration of 9?±?8?ng PCBs/g supplement. When following serving size suggestions, mean daily exposure values ranged from 2.5 to 50.3?ng PCBs/day. Daily exposures for children's supplements were significantly lower than those previously reported for adult supplements and may be explained, in part, by the variability in the amount of fish oil (and PUFA content) in a serving size. Based on this study, factors such as fish oil purification methods (e.g., molecular distillation) and the trophic level of the fish species used to make the fish oil cannot be used as indicators of PCB levels within children's supplements. Fish supplements may decrease or increase daily PCB exposure compared with ingestion of fresh fish. However, eating fish high in omega-3 PUFAs and low in PCBs may reduce PCB exposure compared with daily supplementation with fish oils for some products studied.