Thermal and quality evaluation of vegetable oils used in ruminant feed

Dairies add fat supplements to the diets of small ruminants to increase energy production and consequently the production and quality nutritional and sensorial of the milk. This study investigated the thermal and oxidative stability of babassu, castor, faveleira, and sesame oils by TG/DTA and PDSC. The profile of the fatty oils studied was determined by GC–MS as well as physicochemical characteristics. The thermogravimetric profile of the oils indicated that mass loss was caused by the decomposition or volatility of the triacylglycerides. Faveleira and sesame oils showed a high percentage of polyunsaturated fatty acids, especially C18:2. From a nutritional standpoint, unsaturated oils are more suitable supplements for animals because they promote biochemical changes beneficial to human health.     

Encapsulation of Jojoba and Andiroba Oils by Miniemulsion Polymerization. Effect on Molar Mass Distribution

Summary: This paper aims to study the encapsulation of jojoba and andiroba oils via miniemulsion polymerization. The effect of different hydrophilic monomers (acrylic or methacrylic acid), co-stabilizers (hexadecane, jojoba oil or andiroba oil) and initiator concentrations were evaluated. Results indicated the formation of particles with nanocapsule morphology when either hexadecane or jojoba oils were used. When andiroba oil was used no phase separation could be detected in polymer particles and molar mass distributions showed a shoulder of intermediate molar masses between those of the oil and of the pure polymer.     

Thermal characterization of oil and biodiesel from oiticica (<Emphasis Type="Italic">Licania rigida</Emphasis> Benth)

Searching for other alternative sources, which are not part of the food chain, and which are able to supply the biofuel market is a promising option. In this context, it has been searched to investigate the oiticica oil, approaching its availability to the biodiesel synthesis, as well as its thermal stability. Few works retreat parameters such as: the optimization of the biodiesel synthesis, its physical–chemical properties, and thermal parameters etc. The characterization results revealed that the oil showed very high kinematic viscosity, and acidity value around 13 mg KOH/g, requiring a pre-treatment. To reduce the acid in the oil, it has been done the esterification of oil, which was studied in different molar ratios oiticica oil/ethanol (1:9) and 2.0% catalyst, in order to get the best reduction the index of acidity. The lowest level of acidity of the oil obtained after the esterification was 4.4 mg KOH/g. The reaction rate for the synthesis of biodiesel, compared to the initial mass of oiticica oil ester was 85%. This income can be overcome by pursuing an even smaller reduction of acid value of biodiesel oiticica. The acid value of biodiesel was 1.8 mg KOH/g. The results have revealed that the oiticica oil and biodiesel are stable at 224 and 179 °C, respectively.     

Degradation of β-Carbolines Harman and Norharman in Edible Oils during Heating

The β-carbolines, mainly including harman and norharman, are a group of naturally occurring, plant-derived alkaloids, and are also considered as nonpolar heterocyclic aromatic amines. Sesame seed oils contain a high level of β-carbolines (harman and norharman). In China, sesame seed oil blends are one of the most popular types of vegetable oils blends, which can be used as cooking oils or frying oils. Thus, it is meaningful to investigate the degradation of β-carbolines (harman and norharman) in sesame seed oil blends as frying oils during heating. In this work, the loss of harman and norharman in different types of sesame seed oil blends have been investigated. The results showed that the degradation of harman and norharman were dependent both on the type of oil blends, heating temperature and time. Harman and norharman were more degraded during heating (150 °C, 180 °C) in oleic acid-rich oil blends compared to polyunsaturated acid-rich oil blends. Mechanistic investigation suggested that the reduction in harman and norharman in oil blends during heating was mainly due to the oxidative degradation reaction between β-carbolines and lipid oxidation products. Therefore, the contents of β-carbolines (harman and norharman) in sesame seed oil blends when used as frying oils and heated can be decreased with prolonged cooking time.     

Comparative study of the oxidative and thermal stability of vegetable oils to be used as lubricant bases

Demand for lubricating oils is increasing in the growing Brazilian economy. The use of vegetable bases in exchange of minerals can bring socio-economic and environmental benefits for Brazil. The purpose of this study is to compare the thermal and oxidative stability of vegetable oils related to the bases commonly used as lubricants. In this study, thermogravimetric analysis of castor oil, cotton oil, macauba’s almond oil, passion oil, paraffinic mineral oil, naphthenic oil (NH-140) and synthetic oil (Etro) was performed in inert and oxidative atmosphere to study the thermal and oxidative degradation of the vegetable oils related to the most common lubricants’ oils base. These oils’ oxidation stability were determined by standard procedures (ISO 6886). The use of mineral oil’s additives in these vegetable oils was tested to verify the viability of these additives to improve the oxidative stability of the vegetable oils. The castor oil and the cotton oil presented results of thermal analysis similar to the mineral and synthetic bases values. The castor oil was the only vegetable oil that showed a great oxidative stability. All other vegetable oils had their oxidative stability significantly increased by the additives.     

Thermo-oxidative decomposition of biodiesel samples obtained from mixtures of beef tallow,soybean oil,and babassu oil

Biodiesel can be obtained from various fatty acid sources. Each raw material has a different chemical composition that leads to different properties. Owing to these properties, the mixture of different proportions of raw materials can lead to biodiesels with best features in relation to physicochemical parameters such as viscosity, oxidative stability and flow properties, generating a fuel whose characteristics meet the requirements of the current legislation of the Brazilian National Agency of Petroleum, Natural Gas and Biofuels (ANP). The objective of this study was to determine the physicochemical properties of biodiesel samples produced from mixtures of beef tallow, babassu oil, and soybean oil. The thermo-oxidative stability was evaluated using thermogravimetry (TG/DTG) and differential scanning calorimetry (DSC). The results showed that all samples were in accordance to the ANP specifications. The biodiesel obtained from a mixture containing 50% of babassu oil had lower values of pour point, cold filter plugging point, and freezing point. This biodiesel also showed a higher thermo-oxidative stability in synthetic air and in oxygen atmospheres.     

Thermal decomposition of biodiesel fuels produced from rapeseed, jatropha, and coffee oils with different alcohols

Thermal behaviors and the effects of various alcohols on biodiesel fuel (BDF) derived from edible oil such as rapeseed oil and inedible oils such as coffee oil and jatropha oil, were studied. TG curves in air and N₂ of rapeseed BDF, jatropha BDF, drip coffee, and BDF espresso coffee BDF synthesized from the methanol presented similar results which exhibited only one mass loss step, which is attributed to vaporization or combustion of the methyl esters. The decomposition temperature (T _d) of rapeseed, jatropha and coffee Bt-BDF were high by about 30 °C compared with the standard, Me-BDF. The amount of decomposition residue at 400 °C was found to be related to the number of carbon atoms in the alcohol, with the residue becoming greater with more carbons in the alcohol. The oxidation stability of rapeseed BDF depended on the carbon chain of the alcohol. However, coffee and jatropha BDFs were stable in spite of the long chain alcohol.     

In Vivo Evaluation of the Photoprotective Efficacy of O1/W/O2 Multiple Emulsions with Andiroba Oil (Carapa guianensis)

Stable multiple emulsions containing andiroba oil and sunscreen have been formulated. These were prepared using the two-step procedure. The formulations were characterized and their stability over the time was evaluated by centrifugation, macroscopic, and microscopic analyses, and rheological measurements. The photoprotective efficacy of the O/W and O₁/W/O₂ containing or not andiroba oil was evaluated by in vivo sun protection factor determination according to the FDA method. The formulations exhibited good stability during 30 days after preparation at different temperatures. These presented pseudoplastic flow behaviour and thixotropy. The increase of in vivo SPF value was not observed when andiroba oil was incorporated into emulsions containing ethylhexyl methoxycinnamate. These multiple emulsions can be utilized as an interesting topical vehicle.     

Evaluation of jatropha oil to produce poly(3-hydroxybutyrate) by Cupriavidus necator H16

Jatropha oil, a non-edible vegetable oil, may be an alternative substrate to food-grade oils for bioplastic production. Jatropha oil contains 93.9% palmitic acids, oleic acids and linoleic acids. High P(3HB) accumulation of 87 wt% from 13.1 g/L of cell dry weight (CDW) was obtained by Cupriavidus necator H16 when 12.5 g/L of jatropha oil and 0.54 g/L of urea were used. Lipase activity increased in the initial stages of P(3HB) production, when 1 g/L of jatropha oil was added to the preculture medium. Addition of oil in preculture did not affect final CDW or P(3HB) accumulation. P(3HB) production in a 10 L lab-scale fermenter gave a yield of 0.78 g P(3HB) per g jatropha oil used after 48 h. For the first time, this study proved that jatropha oil is a feasible and excellent carbon source for P(3HB) biosynthesis by C. necator H16 with potential for large-scale production. The toxins in jatropha oil did not affect the P(3HB) biosynthesis.     

傅里叶变换红外吸收光谱识别五种植物油的研究

以花生油、大豆油、芝麻油、棉籽油和米糠油为样品,采用傅里叶变换红外光谱仪,采集傅里叶变换红外吸收光谱,对光谱预处理后,提取红外特征信息,以1746cm-1和2855cm-1处的吸收峰面积比值为横坐标,1099cm-1处与1119cm-1处的吸收峰面积比为纵坐标,在Origin6.0上做出二维分布图,对各种油脂进行识别分析。结果显示,大豆油与其它4种油脂之间有明显区分;大豆油、花生油和芝麻油分布效果好,但棉籽油各样品点之间比较分散;能与其它油脂区分开的有以下几种分布花生油明显区别于芝麻油、棉籽油和大豆油;米糠油明显区别于棉籽油和大豆油。分布有交叉的油脂有米糠油与花生油或芝麻油有交叉,棉籽油与芝麻油有交叉。     

常压火焰离子化质谱技术对食用植物油快速分析的初探

建立了常压火焰离子化质谱(Ambient flame ionization mass spectrometry,AFI-MS)快速分析食用植物油(橄榄油、芝麻油、花生油和葵花籽油)的方法。AFI-MS检出食用植物油(橄榄油、芝麻油、花生油和葵花籽油)中的26种甘油三酯和11种甘油二脂。AFI-MS分析显示,不同的食用植物油(橄榄油、芝麻油、花生油和葵花籽油)得到的质谱图轮廓信息不同。通过对不同食用植物油的甘油三酯相对峰强度进行分析,可初步归纳出食用植物油的类型。AFI-MS分析食用植物油的操作简单,普通的打火机就可以作为离子源用于食用植物油的分析。这种便捷的离子化技术可以用于食用植物油的快速分析。     

Determination of Edible Vegetable Oil Adulterants in Sesame Oil Using 1H Nuclear Magnetic Resonance Spectroscopy

An NMR method is reported for the determination of sesamin to verify the authenticity of sesame oil. The intensity of the well-resolved H2′ sesamin signal resonating at approximately 5.95 ppm is strongly correlated with the amounts of other types of vegetable oils present in the adulterated sesame oil using the relationship, y = 4.020x + 1.516 (r ²  = 0.9967). The H2′ peak intensity of sesamin was measured for sesame oil extracted directly from the mill-sourced sesame seeds because the sesame oils purchased from local markets could be adulterated. Additionally, the oils used were obtained from the seeds native to China and the Republic of Korea, because the sesamin concentrations may vary from region to region. The proposed ¹H NMR method allows for the simple identification and determination of cheaper vegetable oils used as adulterants in sesame oil. High-performance liquid chromatography was used to confirm the validity of the results obtained by NMR.     

气相色谱法与麻油纯度试验法在芝麻油掺伪鉴定中的应用

用气相色谱法和麻油纯度试验法对芝麻油掺伪情况进行分析。用气相色谱法分析脂肪酸组成,测定植物油中的主要脂肪酸,来确定是何种油或掺入其它何种植物油;麻油纯度试验法用于定量。两者可结合起来使用。     

Thermo-oxidative stability and cold flow properties of babassu biodiesel by PDSC and TMDSC techniques

The babassu (Orbignya Phalerata Mart.) biodiesel has lauric esters as main constituents, resulting in high oxidative stability and low cloud and freezing points. In order to reduce these side effects, the saturated ethyl esters content was reduced by means of winterization process. The TMDSC and PDSC techniques were used to verify the thermal and oxidative stabilities of the ethyl babassu biodiesel. During the heating stage, the winterized solid phase of ethyl esters presented an endothermic transition associated to the solidification process. This behavior was not observed for the liquid winterized FAEE, confirming the efficiency of the winterization process.     

The Effect of Wall Material Type on the Encapsulation Efficiency and Oxidative Stability of Fish Oils

Fish oil is the primary source of long-chain omega-3 fatty acids, which are important nutrients that assist in the prevention and treatment of heart disease and have many health benefits. It also contains vitamins that are lipid-soluble, such as vitamins A and D. This work aimed to determine how the wall material composition influenced the encapsulation efficiency and oxidative stability of omega fish oils in spray-dried microcapsules. In this study, mackerel, sardine waste oil, and sand smelt fish oil were encapsulated in three different wall materials (whey protein, gum Arabic (AG), and maltodextrin) by conventional spray-drying. The effect of the different wall materials on the encapsulation efficiency (EE), flowability, and oxidative stability of encapsulated oils during storage at 4 °C was investigated. All three encapsulating agents provided a highly protective effect against the oxidative deterioration of the encapsulated oils. Whey protein was found to be the most effective encapsulated agent comparing to gum Arabic and maltodextrin. The results indicated that whey protein recorded the highest encapsulation efficiency compared to the gum Arabic and maltodextrin in all encapsulated samples with EE of 71.71%, 68.61%, and 64.71% for sand smelt, mackerel, and sardine oil, respectively. Unencapsulated fish oil samples (control) recorded peroxide values (PV) of 33.19, 40.64, and 47.76 meq/kg oil for sand smelt, mackerel, and sardine oils after 35 days of storage, while all the encapsulated samples showed PV less than 10 in the same storage period. It could be concluded that all the encapsulating agents provided a protective effect to the encapsulated fish oil and elongated the shelf life of it comparing to the untreated oil sample (control). The results suggest that encapsulation of fish oil is beneficial for its oxidative stability and its uses in the production of functional foods.     

Cetane number and thermal properties of vegetable oil,biodiesel, 1-butanol and diesel blends

Vegetable oil derived fuels for diesel engines are becoming important as alternative to petroleum diesel fuels due to their environmental friendliness and availability. Ignition quality in compression ignition (CI) engines is influenced by thermal characteristics and fuel properties. In this study, the effects of vegetable oil transesterification and vegetable oil–1-butanol-diesel blends on fuel properties, cetane number (CN) and thermal characteristics were experimentally investigated. Methyl esters (biodiesel) and 10% vegetable oil–10% 1-butanol–80% diesel blends were prepared from croton oil (CRO), coconut oil (COO) and jatropha oil (JAO). CN was measured in a CFR F-5 engine, and a thermogravimetric analysis (TG), as well as the determination of fuel properties of vegetable oils, biodiesels and blends was carried out. It can be observed for vegetable oils that they possess low volatility characteristics, low CN and high viscosity different from those of biodiesels, blends and diesel fuel. It was observed that biodiesels and blends exhibit similarities with diesel in the fuel characteristics, CN and TG curves.     

Fast quantitative detection of sesame oil adulteration by near-infrared spectroscopy and chemometric models

Adulteration of foods has been known to exist for a long time and various analytical tests have been reported to address this problem. Among them, authenticity of sesame oil has attracted much attention. Near-infrared (NIR) spectral quantitative detection models of sesame oil adulterated with other oils are constructed by chemometric methods, i.e., competitive adaptive reweighted sampling (CARS), elastic component regression (ECR) and partial least squares (PLS). Sixty samples adulterated with different proportions of five kinds of other oils of lower price were scanned by a Fourier-transform-NIR spectrometer and the NIR spectra were collected in 4500–10000 cm⁻¹ region by transmission mode. All samples were divided into the training set and an independent test set. Model population analysis has also been carried out and confirms the importance of selecting representative samples. The experimental results indicate that the PLS model using only 10 variables from CARS and the ECR model show similar performance and both are superior to the full-spectrum PLS model. CARS focuses on selecting variables and ECR focuses on optimizing the parameters, implying that both roads lead to the same destination. It seems that NIR technique combined with CARS or ECR is feasible for rapidly detecting sesame oil adulterated with other vegetable oils.     

不同波长的光对生物柴油氧化安定性的影响

为了研究光对生物柴油氧化安定性的影响,以小桐子生物柴油为研究对象,在20 ℃下用不同波长的光照射处理48 h,并对处理后的样品进行氧化安定性分析。 结果表明,不同波长的光对生物柴油氧化的促进作用是不同的,以紫光为代表的短波长光对小桐子油生物柴油氧化的促进作用最强,其诱导期由5.12 h降至2.65 h,减少48%;波长较长的红光对生物柴油氧化的促进作用最弱,其诱导期降至4.61 h,减少10%。 对不同波长的光处理的生物柴油进行酸值滴定、成分分析和紫外表征,结果表明,随着光波长的减小,生物柴油的酸值从0.2577 mg/g 增加到0.3438 mg/g;含有两个碳碳双键的亚油酸甲酯的相对含量降低;共轭双键的吸收峰增大。 说明光波长越短,对生物柴油氧化的促进作用越强。     

Efficacy of natural oils and conventional chemicals in the physical extraction of 4-hydroxybenzoic acid from aqueous solution

4-hydroxybenzoic acid (4-HBA) is a phenolcarboxylic acid and a valuable chemical with various pharmacological properties and a wide range of industrial applications. The present work is envisioned to retrieve 4-HBA from aqueous solution through physical extraction using natural oils (mustard oil, sunflower oil and soyabean oil) and chemicals (MIBK and 1-octanol) as solvent. The experimental evaluation of extraction equilibrium using aforesaid solvents is reported in the form of distribution coefficient (K_D), extraction efficiency (E_P %), partition coefficient (P) and dimerization constant (D). The results were analysed using several physicochemical aspects of the solvents utilized, such as the solvent polarity parameter, dielectric constant, and dipole moment. Further, the comparison of these extraction results was made with the results of our previous study which was with the solvents sesame oil, canola oil, benzene, toluene and p-ether. The results may be arranged in the increasing order with respect to average K_D and average E_P % for natural oils as canola oil (0.23, 18.85%) < mustard oil (0.25, 20.45%) < sunflower oil (0.27, 21.00%) < soyabean oil (0.34, 25.06%) < sesame oil (0.49, 33.24%) and for chemicals as benzene (0.08, 7.5%) < toluene (0.09, 8.25%) < p-ether (0.09, 8.32%) < MIBK (2.55, 71.41%) < 1-octanol (5.01, 83.01%).     

GC-IMS技术结合化学计量学方法在食用植物油分类中的应用

建立了一种快速、无损分析食用植物油中挥发性有机物质的顶空进样/气相色谱-离子迁移谱(GC-IMS)联用方法。以芝麻油、菜籽油、山茶油共56个样品为研究对象,量取2 mL待测油样于标准样品瓶中,并用磁帽密封,直接进行GC-IMS分析检测。结果表明,基于GC-IMS三维谱中对应挥发性有机物质的特征峰强度可以有效表征不同类植物油的样品信息,选取对应三维谱中40个特征峰的强度作为变量,进行主成分(PCA)信息降维后,采用k最近邻(kNN)算法建立植物油种类的判别模型,训练集的识别率达到100%,预测集中仅有1个山茶油样品被误判成芝麻油样品,预测集的识别率达到94.44%。GC-IMS联用分析技术简单、快速、无损,可用于食用植物油等其他食品、农产品种类的快速分类识别。