紫丁香叶提取物在食用油脂中的抗氧化作用

以猪油和精炼的一级大豆油为对象,研究了紫丁香叶提取物在不同添加量时对油脂的抗氧化作用.结果表明,紫丁香叶提取物对油脂氧化有很强的抗氧化作用,其作用效果与没食子酸丙酯相近,且抗氧化能力随着用量的增加而增强.     

二氢杨梅素月桂酸酯在猪油中的抗氧化性研究

用月桂酰氯对二氢杨梅素的羟基进行酯化，合成了二氢杨梅素月桂酸酯。并对二氢杨梅素月桂酸酯结构进行了红外光谱表征。通过对二氢杨梅素及二氢杨梅素月桂酸酯在猪油中抗氧化性能比较试验，证实二氢杨梅素月桂酸酯能够持久、稳定地在猪油中发挥抗氧化作用，在猪油中的抗氧化能力比二氢杨梅素强，而二氢杨梅素在猪油氧化后期起到了促氧化作用。通过对二氢杨梅素月桂酸酯在猪油中不同添加量抗氧化试验，得出二氢杨梅素月桂酸酯在猪油中的最佳添加量为1．0mmol/L。     

五倍子提取物及其衍生物复合抗氧化剂对大豆油贮藏稳定性研究

为探究五倍子提取物及其衍生物对大豆油贮藏期的影响,采用气相色谱-质谱联用法测定大豆油主要脂肪酸的组成,利用Schaal烘箱法加快大豆油氧化,研究五倍子提取物没食子酸及其衍生物没食子酸丙酯等天然物质对大豆油的抗氧化效果,运用响应面法优化研究大豆油的复合天然抗氧化剂配方,并预测其贮藏期。结果表明：单一抗氧化剂对大豆油的抗氧化效果从高到底依次为没食子酸、没食子酸丙酯以及柠檬酸,响应面优化抗氧化剂最佳配比为没食子酸为0.023%、没食子酸丙酯为0.008%、柠檬酸为0.028%。大豆油添加复合天然抗氧化剂后,预测20℃下其货架期为344.8 d,效果优于茶多酚,接近特丁基对苯二酚,与未添加抗氧化剂的大豆油相比,货架期延长6.05倍。该结果可针对性地为大豆油的新型复合天然抗氧化剂研究提供理论依据。     

没食子酸丙酯对猪油的抗氧化效果研究

目的 研究不同浓度的没食子酸丙酯(propyl gallate,PG)对猪油抗氧化效果的影响。方法 以酸价(acid value,AV)、过氧化值(peroxide value,PV)、茴香胺值(ρ-anisidine value,ρ-AnV)、1,1-二苯代苦基苯肼(1,1-diphenyl-2-picryl-hydrazyl, DPPH)自由基清除能力和脂肪酸组成为指标,采用Schaal法检测猪油抗氧化性能,结合Rancimat法测得高温下的氧化稳定性指数(oxidation stability index, OSI),比较了不同浓度(0.02、0.04、0.06、0.08、0.10g/kg)的PG对猪油的抗氧化效果,通过主成分分析得出PG在猪油中应用的最佳浓度。结果 PG能够有效延缓猪油各项氧化基础指标的升高,且对其脂肪酸组成无显著影响(P>0.05),可作为一种安全高效的抗氧化剂应用于猪油中。主成分分析结果表明,添加0.10g/kg为PG在猪油中应用的最佳浓度,其AV (1.83 mg/g)和PV (1.30 g/100 g)在Schaal烘箱实验15 d后最低,ρ-An...     

抗氧剂乙酰阿魏酸芳香醇酯的合成及性能研究

以乙酰阿魏酸为原料,通过酰化反应制备了乙酰阿魏酰氯再与芳香醇进行酯化反应,合成了四种乙酰阿魏酸芳香醇酯。采用IR(红外光谱)和1H NMR(核磁共振)对目标化合物进行了分析与表征。以食用猪油为底物,过氧化值(POV)的测定采用GB/T5538—2005的标准方法,对产物抗氧化活性进行了评价。结果表明:乙酰阿魏酸芳香醇酯对食用猪油均有一定的抗氧化能力,其中乙酰阿魏酸苯甲醇酯抗氧化效果最好;当乙酰阿魏酸苯甲醇酯的添加量为0.02%时,其抗氧化能力为12.01meq/kg,与BHT(2,6-二叔丁基-4-甲基苯酚)相近。     

L-抗坏血酸脂肪酸酯抗氧化活性

从羟基自由基体系、超氧阴离子自由基体系、二苯苦味肼基自由基体系及还原力测试等方面研究L-抗坏血酸脂肪酸酯(VC脂肪酸酯)体外抗氧化活性,并将其添加到猪油和大豆油当中,评价其抗氧化效果.结果表明,在一定的质量浓度范围内,VC脂肪酸酯对羟自由基、超氧阴离子自由基、DPPH自由基均有较好的清除效果,还原能力也较强,并呈一定量效关系,其抗氧化活性与L-抗坏血酸棕榈酸酯相当.VC脂肪酸酯在猪油中的添加质量分数为0.2%,100℃下强制氧化20h时,猪油的过氧化值为42.8 meq/kg,具有明显的抗氧化活性;在大豆油中添加质量分数0.2%,强制氧化14 h时,大豆油的过氧化值为11.9 meq/kg,其抗氧化能力大于TBHQ,与L-抗坏血酸棕榈酸酯接近,说明VC脂肪酸酯是一种有潜力的食品抗氧化剂.     

厚朴的抗氧化性能

采用不同极性的溶剂对厚朴粉末进行提取,采用OSI(OxidativeStabilityInstrument)法对提取和分离所得各部分的抗氧化活性作了比较研究。结果发现,用乙酸乙酯提取的厚朴抗氧化剂对猪油、鱼油等油脂具有较强的抗氧化活性且得率较高;没食子酸辛酯(OG)、没食酯酸十二酯(DG)对厚朴抗氧化剂具有较强的协同增效作用.研究表明,厚朴乙酸乙酯提取物作为抗氧化剂有望应用于食品和医疗保健.     

无溶剂体系生物合成阿魏酸双甘酯对油脂抗氧化性能的研究

采用生物催化的方法合成具有生理活性的阿魏酸双甘酯。以过氧化值(POV)为指标研究不同剂量的阿魏酸双甘酯对猪油及花生油的抗氧化性能。结果表明:阿魏酸双甘酯对猪油和花生油都具有一定的抗氧化作用且存在剂量效应关系;添加了阿魏酸双甘酯的猪油和花生油在20℃条件下保存,其货架保存期分别可从3.8个月延长至10个月、2.7个月延长至8.6个月。     

没食子酸酯类抗氧化剂对不同植物油氧化稳定性能影响的研究

没食子酸酯类抗氧化剂是优化植物油脂氧化稳定性能主要添加剂,本论文制备了7种不同酯基结构的没食子酸酯类抗氧化剂并进行了红外光谱表征,分别研究了此7种抗氧化剂对21种植物油脂和地沟油的抗氧化效果。研究结果表明,21种植物油脂和地沟油的氧化稳定性能不同,且差别较大,其中蓖麻子油的氧化稳定性能最好,诱导期时间达到39.19h,最差的是牡丹籽油,诱导期时间为1.03 h,两者相差达到38倍。7种不同酯基没食子酸酯类抗氧化剂对21种植物油脂和地沟油的抗氧化效果十分明显,其中酯基不同的没食子酸酯类抗氧化剂对植物油脂的抗氧化效果不同,且差别较大,其中没食子酸丙酯(PG)对植物油脂的抗氧化效果最好。同一种没食子酸酯类抗氧化剂对不同植物油脂的抗氧化效果有所不同,差别也较大,如没食子酸甲酯(MT)使亚麻籽油抗氧化效果提高了8.23倍,而使蓖麻子油的抗氧化效果提高了1.5倍。支链酯基的没食子酸酯类抗氧化剂与直链酯基的没食子酸酯类抗氧化剂对植物油脂的抗氧化效果相差不大。     

生姜油对猪油抗氧化效果的研究

以过氧化值(POV)和酸价(AV)为指标，研究了生姜油对猪油的抗氧化性能。结果表明：生姜油对猪油具有较强的抗氧化作用，Vc、茶多酚和市售姜油均对猪油有一定的抗氧化性能。     

Effects of lard on the formation of volatiles from the Maillard reaction of cysteine with xylose

BACKGROUND: The presence of lipid oxidation products in the Maillard reaction pathway is of particular interest today. The objective of this study was to investigate the effect of lard and its oxidation products on the formation of volatiles from cysteine and xylose model systems. RESULTS: Headspace volatiles generated in reaction mixtures were examined by solid‐phase microextraction in combination with gas chromatography‐mass spectrometry. The addition of lipid had a suppressing effect on most of the sulfur‐containing compounds derived from the reaction between cysteine and xylose, especially for 2‐methyl‐3‐furanthiol, 2‐furanmethanethiol, 2‐methylthiophene, and 3‐methylthiophene. One of the intermediates—furfural—was also formed in much lower concentration when lard was present. In addition, cysteine and xylose modified lipid oxidation pathways, so that lipid‐derived alcohols, alkylfurans and aliphatic acids were formed rather than aldehydes. Compared with the lard heated alone, most aldehydes were formed at lower levels in the lard‐containing reaction mixtures, and several aldehydes including hexanal, heptanal, (2E)‐heptenal and (2E,4E)‐heptadienal were absent. CONCLUSION: The addition of lipid was inhibitory to the formation of most sulfur‐containing compounds in the Maillard reaction. Furthermore, Maillard reaction products influenced the formation of products from lipid oxidation. Copyright © 2011 Society of Chemical Industry     

Composition and thermal analysis of ternary mixtures of avocado fat:palm stearin:cocoa butter (Avo:PS:CB)

Avocado fat is a semi-solid substance with potential functional lipid characteristics. A study was carried out to evaluate the effect of addition of palm stearin and cocoa butter on the solidification behavior of avocado fat to formulate a mixture to become similar to lard. A total of three mixtures were prepared: avocado fat:palm stearin:cocoa butter (88:7:5), avocado fat:palm stearin:cocoa butter (86:7:7), avocado fat:palm stearin:cocoa butter (84:7:9; w/w), and identified by the mass ratio of avocado fat to palm stearin and cocoa butter. The fat mixtures were compared with lard in terms of the fatty acid and triacylglycerol compositions using gas chromatography and high-performance liquid chromatography, thermal properties using differential scanning calorimetry and solid fat content using p-nuclear magnetic resonance. Although there were considerable differences between lard and the fat mixtures with regard to fatty acid and triacylglycerol compositions, some similarities were seen with regard to thermal properties and solid fat content profile. Of all the fat mixtures, avocado fat:palm stearin:cocoa butter (84:7:9) displayed closer similarity to lard with respect to thermal transitions at –3.59°C and its solid fat content profile showed the least difference to that of lard throughout the temperature range measured.     

Effects of vegetable fats versus lard in milk replacers on feed intake, digestibility, and growth in Finnish Ayrshire bull calves

The aim was to study whether vegetable fat mixtures could be used instead of lard [15.2% in dry matter (DM)] in milk replacers without impairing the performance of Finnish Ayrshire bull calves (n = 58). The growth performance of the calves was measured before and after weaning from 14 d to 6 mo of age. The following 3 fat sources in a milk replacer were studied: 1) a mixture of palm, coconut, and rapeseed oil, 2) palm and coconut oil, and 3) lard. The calves were bucket-fed 2 L of milk replacer 3 times per day. The milk replacer contained 116 g of DM/L, resulting in an average DM intake of 4.8 g of DM/kg of body weight^0.75 (BW^0.75) during the 8-wk trial, after which the calves were weaned. All the calves had free access to water, commercial starter, and grass silage before weaning. The weaned calves had free access to water and grass silage and were given 3 kg/d (air-dry basis) of a commercial concentrate mixture. The concentrate was replaced by barley when the bulls were 4.5 mo old. There were no significant differences between the diets in feed intake and apparent diet digestibility. The health and BW of the calves were similar during the study. The feed conversion rate (kg of DM intake/kg of gain) before weaning was significantly greater for the lard diet compared with the 2 vegetable fat mixtures. After weaning, the feed conversion rate was slightly lower for the diet that included the palm, coconut, and rapeseed oil mixture than for the diet that included palm and coconut oil mixture. The study showed that the 2 mixtures consisting solely of vegetable oils were effective dietary components, thus providing 2 alternative fat mixtures of milk replacers, for use instead of lard in formulating commercial calf milk replacers.     

Sub-ambient differential scanning calorimetry of lard and lard contaminated by tallow

DSC scans of lard, cow tallow and admixtures were determined by cooling from 70 to −50°C. Analysis of the thermograms indicated that tallow could be detected in lard at concentrations above 1%, although the relative error of determination was large. For mixtures with tallow contents in the range of 6–26%, the relative error in the estimation of tallow content was in the range of 10–1%, respectively.     

Effects of Fractionation and the Refining Process of Lard on Cholesterol Removal by β-Cyclodextrin

Lard was fractionated into olein and stearine, and lard olein was further refined. The effects of fractionation and refining of lard on the removal of cholesterol by β- cyclodextrin (β-CD) were investigated. The cholesterol in refined lard was more easily removed by β-CD; more than 90% of cholesterol in bleached lard was effectively removed by stirring with 4%β-CD. The oxidative stability of lard was increased after bleaching. Fractionation not only reduced the cholesterol content but also the saturated fatty acids in lard. Considering the cholesterol removal efficacy and lard quality, the optimal step for cholesterol removal in lard by β-CD is between bleaching and deodorization.     

超声和酶处理对乳化猪油体外消化特性的影响

本研究以猪油为原料,超声诱导脂肪晶体发生重排,采用谷氨酰胺转氨酶（transglutaminase,TG）交联 浓缩乳清蛋白作为乳化剂,制备改性乳化猪油,进而探讨乳化猪油未吸附蛋白含量的变化,并在体外消化模型中以 平均粒径、Zeta电位、游离脂肪酸释放量以及脂肪颗粒微观结构作为评价指标,对改性乳化猪油体外消化特性进行 研究。结果表明,超声和TG处理分别对乳化猪油产生不同的作用,超声处理后乳化猪油未吸附蛋白含量低于未处 理样品,乳化稳定性降低,而TG处理则提高了乳化猪油的乳化稳定性。超声处理后的乳化猪油在体外消化过程中 的游离脂肪酸的释放量、平均粒径显著高于未处理样品（P＜0.05）,Zeta电位明显低于未处理样品。而TG交联浓 缩乳清蛋白促使乳化猪油颗粒更加细小,在体外消化过程中游离脂肪酸的释放量显著降低（P＜0.05）。超声处理 的乳化猪油更易于消化,TG处理则减缓了乳化猪油的消化速率。     

猪油脂产品特性及其氧化稳定性研究

该研究对经表面活性剂分提四种猪油脂产品进行理化指标测试,并对产品氧化稳定性进行分析,以期更好开发猪油脂产品。     

猪油的开发利用

介绍了猪油的主要组成及性质。对食品工业中液化猪油、猪油精制、粉末猪油脂等方面的研究进展作了详细论述。在猪油的工业应用中，着重介绍了猪油改性、醇解、水解(包括生物酶催化水解)、皂化等方面的进展情况。展望了猪油工业的发展趋势，并提出了一些建议。     

不同种类高膳食油脂对小鼠血脂、肝脂及尿酸的影响

为了探讨猪油、植物油及其调和油对血脂、肝脂及血尿酸的影响,评估其对特殊人群的健康潜在风险,本文研究以小鼠为模型,模拟居民用油习惯,将50只8周龄雄性C57BL/6J小鼠随机均分为葵花籽油组(SSO)、豆油组(SO)、猪油组(LO)、葵花籽油与猪油调和油组(SSO-L)、豆油与猪油调和油组(SO-L)5组,模拟我国部分人群(5%~10%)日均烹调油脂高摄入水平(95g/d),每组日粮中分别添加10.5%的不同油脂,饲喂8周后采集血液和肝脏组织,检测血清和肝脏指标。结果显示,相比于其他各组,LO组在体脂和血脂方面都有显著或极显著升高(p0.05,p0.01)。而SSO-L组和SO-L组在肝脂方面显著高于对应的SSO组和SO组(p0.05)。同时,SSO-L组和SO-L组的SUA和肝脏XOD水平都显著高于LO组(p0.05)。表明在95 g/d的膳食油脂摄入水平下,猪油会极大增加肥胖和患脂肪肝病的风险。葵花籽油与猪油调和油和豆油与猪油调和油也会通过升高尿酸水平来增大痛风和脂肪肝的患病风险。此外,长期以该水平摄入这两种调和油对肝脏功能也有明显损伤。在该摄入水平下,豆油为较优选择。     

表面活性剂分提猪油的工艺研究

采用表面活性剂对原料猪油进行二次分提,得到4种形态的猪油;通过正交实验系统考察了二次分提猪油过程中表面活性剂浓度、电解质浓度、养晶温度、养晶时间等对猪油得率的影响,得出一次和二次分提猪油的最佳工艺条件,最后测定了产品猪油的理化指标.