Grape Seed Oil Characterization: A Novel Approach for Oil Quality Assessment

The amount of organic pomace, left behind agricultural processes, is continuously rising in accordance with industrial progress. Grape pomace, generated in the wine industry all over the world, represents a raw material for obtaining valuable products. Grape seeds are especially rich in oil containing bioactive compounds that can have various health‐related effects. The aim of the study is to compare the quality of seed oils obtained from six white grapes, including two Serbian autochthonous varieties. Linoleic acid, associated with numerous health benefits, is the major fatty acid in all samples (≈66% of total); α‐tocopherol is the main tocopherol homologue. Total polyphenol content ranges from 73.4 to 104.3 mg of gallic acid equivalents per 100 g. In order to provide comprehensive information about antioxidant capacity of grape seed oil (GSO), three tests are performed (ferric ion reducing antioxidant power; 2,2’‐diphenyl‐1‐picrylhydrazyl, and 2,2’‐azino‐bis(3‐ethylbenzthiazoline‐6‐sulphonic acid) radical scavenging). Antimicrobial activity is investigated against different strains; however, GSO inhibits the growth of Staphylococcus aureus and Candida albicans. Obtained results are used to develop a novel approach for oil quality assessment. Calculated oil quality scores (OQS) reveal no significant difference between international and autochthonous varieties, although Smederevka stands out as the most potent one. Practical applications : Considering the progressive waste increase in the wine industry and keeping in mind all health‐promoting effects of grape seed oil (GSO), it is clearly observed that oil production represents a profitable and sustainable utilization of grape seeds. The results of the present study show that GSO is a rich source of compounds with antioxidant and antimicrobial properties. In addition, this work provides deeper insight into a quality of Serbian autochthonous grape varieties that are still insufficiently explored. Furthermore, the proposed oil quality score could be used as a comprehensive and unbiased method that enables quality assessment of oils. This tool can find practical application in comparing different plant oils regarding their compositional and functional properties. Finally, it would contribute to making some general oil intake recommendations.     

超临界二氧化碳萃取葡萄籽油的研究

葡萄籽油中富含亚油酸和其它不饱和脂肪酸,具有较高的食用和药用价值。传统的葡萄籽油提取方法存在着收率低和溶剂残留的问题。今基于对酿酒过程中废弃葡萄籽的开发利用,探讨了采用绿色洁净分离技术——超临界流体萃取技术从废弃葡萄籽中萃取葡萄籽油的可行性,重点考察了萃取温度、萃取压力、CO2用量及不同原料对葡萄籽油产率的影响。研究表明萃取压力对产率的影响较温度显著,实验确定适宜工艺条件为萃取温度55C,萃取压力30MPa。此条件下以张裕酒厂提供的籽为原料所得产率为9.71%,同时气相色谱分析表明,葡萄籽油产品中含有72.05%的亚油酸。另外,分别以三种不同来源的葡萄籽为原料进行实验,研究显示,葡萄籽油产率随原料不同而存在一定差异,产率较高者可达13.51%。     

Virgin Grape Seed Oil Alleviates Insulin Resistance and Energy Metabolism Disorder in Mice Fed a High‐Fat Diet

This study aims to investigate the potential of virgin grape seed oil (VGSO) to improve insulin resistance and energy metabolism disorder in mice fed a high‐fat diet. The results show that respiratory exchange rate and energy consumption in mice can be increased by the administration of VGSO. Insulin resistance is significantly alleviated by VGSO, which can be attributed to its protective effect on hexokinase and α‐glucosidase activities and improvement in leptin resistance. The effect of refined grape seed oil (RGSO), RGSO reinforced with polyphenol, RGSO reinforced with unsaponifiables, and RGSO reinforced with polyphenol and unsaponifiables on oral glucose tolerance, homeostasis model assessment of insulin resistance and quantitative insulin sensitivity check index are determined and compared. The results suggest that polyphenol may be the most critical factor for regulating insulin resistance. Specific linear and polynomial equations are provided to explain the correlation between insulin resistance, energy metabolism, and hyperlipidemia. Practical Applications: The effects of virgin grape seed oil (VGSO) on insulin resistance and energy metabolism disorder in mice fed a high‐fat diet were investigated. In addition, the key component in VGSO for regulating insulin resistance was preliminarily investigated. Furthermore, the correlations among fasting blood glucose, triglyceride/cholesterol concentration, and respiratory exchange rate/energy consumption/activity level were investigated. This research will provide a theoretical basis for the development of functional edible oil for high blood lipid, cholesterol, and diabetes patients.     

葡萄籽功能性成分及其应用

综述了葡萄籽功能性成分及其应用,主要介绍了葡萄籽中原花青素、葡萄籽油、白藜芦醇、维生素、单宁等成分所具有的美容保健功能、安全性和应用概况,同时介绍了葡萄籽超微粉的制备技术、优势和应用前景。提出了将葡萄籽超微粉技术应用于美容保健品的生产中,充分发挥葡萄籽功能性成分的作用,生产出功效更为全面的化妆品。     

Virgin grape seed oil: Is it really a nutritional highlight?

In comparison to refined grape seed oil which is neutral in taste and smell, the virgin oil is characterized by a pleasant vinous and fruity aroma, which also reminds of raisins if high‐quality raw material is used for the production. Difficulties arise from the susceptibility of the raw material to microbial and enzymatic deterioration as a result of the high moisture content after pressing the juices from the grapes. Grape seed oil has a high content (70%) of linoleic acid, whereas the total part of unsaturated fatty acids amounts to about 90%. In comparison to other edible oils, the oil contains, in addition to tocopherols, antioxidant‐effective tocotrienols. During the oil pressing process, only a small amount of phenolic compounds is transferred into the oil (0.01 mg/g), while most of these nutritionally interesting components remain in the press cake. Here, the content of phenolic compounds is about 2000 times higher. During storage of virgin grape seed oil, the pleasant sensory attributes change, and more and more degradation products like ethyl acetate, acetic acid or ethanol are detectable. Parts of the seed material, which come into the oil during pressing, result in a faster impairment of the oil.     

Medium‐chain alkyl esters of tyrosol and hydroxytyrosol antioxidants by cuphea oil transesterification

Effective lipophilic antioxidants were prepared by non‐aqueous enzymatic transesterification of plant phenols with cuphea oil. Tyrosol and hydroxytyrosol, abundantly available phenols from olive oil processing byproduct, were found to be predominately acylated with capric acid derived from the triglyceride fraction of the Cuphea germplasm line PSR 23 (Cuphea Viscosissima × C. lanceolata). The reaction was complete within 2 h, with a >97% conversion of either phenol using immobilized Candida antarctica lipase B. The reaction products were good solvents for tyrosol or hydroxytyrosol, suggesting a facile manufacturing route not dependent on use of organic solvents. Phenolic derivatives were assessed for their ability to serve as antioxidants for preventing the oxidation of polyunsaturated fatty acyl groups. The antioxidant capacities of the cuphea‐derived fatty acyl derivatives of tyrosol or hydroxytyrosol were the same as their respective derivatives prepared from decanoic acid. These biobased antioxidants may improve the oxidative stability of sensitive fatty acids in food applications. Practical applications: A new biobased antioxidant was created for the food industry. Foods can contain fats and oils that are susceptible to deterioration during storage, which can limit product quality and shelf‐life. Synthetic antioxidants can slow the spoilage process, although there are limitations to how much can be added to foods. The food industry is interested in using natural ingredients to solve storage stability problems. We found that the oil from the plant Cuphea, cultivated in the upper Midwest region of the US, is very useful for modifying olive oil waste molecules to create antioxidants for use in foods. The developed process would be suitable for commercial production. This research creates a new commercial use for a specialty oil seed crop, expands the market for cuphea oil, and has developed two novel antioxidants to help the food industry improve food quality.     

Influence of natural antioxidants on the formation of trans‐fatty‐acid isomers during heat treatment of sunflower oil

The intake of foods containing trans fatty acids (TFAs) can have deleterious effects on human health, mainly on the cardiovascular system. Thus, it is important to consider the processes that form TFAs in foods, and the alternatives to minimise their formation. The influence of two added natural antioxidants on TFA formation during heat treatment (120 h at 180°C) of sunflower vegetable oil were examined: rosemary extract (Rosmarinus officinalis L.) (1 g per kg oil) and lutein (0.1 g per kg oil). Changes in FA composition were determined using Ag‐ion SPE and gas–liquid chromatography, with total polar compounds determined using dielectric constant measurements and the index of atherogenicity was calculated. Total TFAs with ≥1 trans double bond increased from 0.91 to 1.71% in control samples; this increase was significantly less with both rosemary extract (1.55%) and lutein (1.43%) additions. Among the individual TFAs, significant increases were seen for C18:1,t‐9, C18:2,t‐9,t‐12 and C18:2,c‐9,t‐12/9‐t,12‐c. Polar compounds also increased, with the highest concentrations in control samples, and significantly less with both rosemary extract and lutein additions. According to results of our study, we can summarize that addition of lutein have greater effect on reduction of TFA formation than rosemary extract. Practical applications: Antioxidants, particularly from plants, are widely used in the food industry. They can provide benefits in food preparation, including improving colour, odour and stability, acting as acid regulators and natural preservatives. They have also become accepted by customers and consumers, and so indirectly they have had effects on consumer perception. Addition of natural antioxidants such as rosemary extract is usually limited by the sensory characteristics of the food, with one study showing that addition of rosemary extract at 1–3 g per kg vegetable oil is recommended. The effects of antioxidants on the formation of TFAs in vegetable oils has not been well studied in the literature. Among the already known benefits, the use of such antioxidants as functional ingredients in lipid technologies might reduce the formation of TFAs during thermal treatment.     

Microencapsulation of Chia Seed Oil by Spray-Drying: Influence of the Antioxidant Addition

Chia seed oil has a high content of polyunsaturated fatty acids, giving it nutritionally beneficial qualities, although determining its high susceptibility to oxidative deterioration. Microencapsulation and natural antioxidants are alternatives to protect this oil during its processing and storage. This work aims to study the physicochemical characteristics and the oxidative stability of chia seed oil microencapsulated with different antioxidants (rosemary extract, blend of rosemary and chamomile extracts, ascorbyl palmitate) by spray-drying using sodium caseinate and lactose as wall material. The microencapsulation efficiency and the moisture content are >97% and <3% d.b., respectively. Scanning electron microscopy shows that the microcapsules are spherical, with diameters ranging between 11.3 and 14.8 µm. At t = 0, the microencapsulated oil recorded a t_i = 12.7 h, seven times greater than that of the bulk-oil. The addition of the antioxidants increases the t_i of the microencapsulated oil. The addition of ascorbyl palmitate maintains the peroxide value under the acceptable limit after 60 d of storage (25 °C, darkness, HR 33%). Thus, microencapsulation by spray drying of chia oil with ascorbyl palmitate addition will be the most appropriate studied system to obtain microparticles with high efficiency and oxidative stability during the processing and storage. Practical Application: This study contributes to investigating the microencapsulation of omega-3 fatty acids n-3 fatty acids (FAs) from a novel oilseed (chia oil), applying different antioxidants, including those from vegetable sources such as rosemary and chamomile extracts, to confer additional protection to microencapsulated oil. Thus, the application of these techniques will enable the delivery of this vegetable oil for the development of functional foods.     

Fatty Acid and Phytochemical Compositions of Plantago Seed Oils and Their Functionalities

To develop the potential applications of Plantago plants, seed oils were extracted from 14 cultivars of Plantago around China. Their fatty acid profiles, tocopherols, carotenoid compositions, anti‐inflammatory and antioxidant properties were also investigated. The Plantago seed oils (PSO) were abundant in linolenic acid from 11.12 to 29.36 g/100 g oil and had low fatty acid ratio of n‐6/n‐3 ratio matched with the dietary recommendations. The tocopherol contents of PSO ranged from 693.25 to 3708.80 μg/g and the lutein contents ranged from 2.29 to 26.68 μg/g. The PSO showed significant inhibitory effects on TNF‐α, IL‐1β, and COX‐2 mRNA expression in RAW 264.7 mouse macrophage cells induced by LPS. In addition, the properties on scavenging DPPH, oxygen and hydroxyl radicals indicated that PSO had potential antioxidant properties. The results could develop PSO as novel functional foods to improve human health.     

Protein co-precipitates: A review of their preparation and functional properties

Advances in protein co-precipitation technology over the past two decades have made it possible to commercially produce different types of proteins from mixtures of raw materials. Incorporation of protein co-precipitates improves the functional (e.g. appearance, texture, and stability) and nutritional characteristics of many food products. Increasing world population, increasing demand for and cost of protein-rich foods, and the continuing need to improve the nutritional and functional properties of protein ingredients have contributed to greater research into blends or composites as food ingredients. Protein co-precipitates have a range of biological, physical, chemical, functional, sensory and nutritional properties giving the potential application as ingredients in the food industry, though relatively little published information is available on this subject. There is limited information about the use of protein co-precipitates by the food industry when developing products for different groups of potential consumers. The aim of this review is to evaluate the current status of protein co-precipitate research as a potential way of improving utilization of protein rich raw materials (e.g. dairy protein), oil seed meals (e.g. sesame, soybean, flaxseed and canola) and by-products (e.g. brewing yeast). By blending proteins from different sources, protein co-precipitates are a way of overcoming deficiencies in essential amino acid contents found in proteins from a single source, which giving ingredients with good functional properties and desirable sensory characteristics.     

葡萄籽油浸提工艺的研究

以葡萄酒厂副产品葡萄籽为原料,石油醚（30～60℃）为浸提剂,利用索氏提取器提取葡萄籽油。考察了粉碎粒度、料液比、浸提浴温、浸提时间对葡萄籽油提取率的影响。结果表明：葡萄籽粉碎粒度为60目,料液比（g/mL）1∶6,浸提浴温80℃,浸提时间120 min时葡萄籽精油提取率为14.86%。实验制得葡萄籽油理化指标均符合国家食用油标准。     

葡萄籽中原花青素的提取与纯化

文章以青岛大泽山葡萄籽为原料,利用溶剂提取法来提取活性物质原花青素,通过正交实验考察了提取溶剂、粉碎粒度、料液比三因素对提取效果的影响。获得了较优的提取条件：丙酮-水体系的最佳提取条件为：葡萄籽粒度60-80目,丙酮浓度40％,料液比1：6（g·mL^-1）。实验还对粗产物进行了提纯,提纯后的产品纯度平均为93％,最高可达96．78％;提纯率平均为32．36％,最高可达42．69％。并在此基础上考察了微波辅助浸提对提取效果的影响。     

Lipid characteristics and phenolics of native grape seed oils grown in Turkey

Grape seed oils of seven native Turkish cultivars (namely Atfi, Mazruna, Black Kerkü?, Zeyti, Verdani, Karfoki, and Kerkü?) were evaluated for their fatty acids, tocols, phytosterols as well as total phenolics and oxygen radical absorbance capacity (ORAC) values. Among the fatty acids, linoleic acid (18:2ω6) was the most abundant (56.38–68.56%), followed by oleic acid (16.45–29.38%, 18:1ω9), palmitic acid (8.19–9.44%, 16:0), and stearic acid (3.74–4.98%, 18:0). Total tocopherols and tocotrienol amounts varied in the range of 102.30–305.43 and 251.47–468.22 mg/kg, respectively. Beta‐sitosterol was the most abundant sterol among grape cultivars whose concentration ranging from 64.19 to 71.62%. Total phenolic content ranged from 2.19 to 4.70 mg of gallic acid equivalents/100 g oil, being lowest in Zeyti and highest in Verdani. With respect to antioxidant activities, a large variation in ORAC values was observed among grape seed oils (ranging from 1048 µmol of Trolox equivalents (TE)/100 g in Karfoki to 2569 µmol of TE/100 g in Mazruna). Practical applications: The crude grape seed oils extracted from different cultivars are a good source of nutrients, fat‐soluble bioactives, and health‐promoting components.     

Content of Antioxidants,Antioxidant Capacity and Oxidative Stability of Grape Seed Oil Obtained by Ultra Sound Assisted Extraction

The goal of this work was to investigate the relationship between antioxidants’ content and the oxidative stabilities of grape seed oils obtained from the Cabernet Sauvignon variety. The samples of grape seed oils were obtained by ultrasound assisted extraction. The time of extraction was varied, while the other relevant parameters: extraction temperature, solvent to solid ratio and sonication power were kept constant. For the sake of comparison, the extraction was also done using the conventional Soxhlet method. For all the oil samples obtained, the contents of total phenolic compounds (TPC), α-tocopherol and fatty acids were determined using relevant analytic methods. Importantly, in the present study, the modern analytical techniques for estimation of antioxidant capacity (measuring the chemiluminescence intensity of a luminol-hemin solution) and oxidative stability [differential scanning calorimetry (DSC), coupled with thermogravimetry (TG)] were proposed. The obtained results prove that ultrasonic irradiation enables effective extraction of grape seed oil. It was shown that the extractive yields and the amounts of total phenolic compounds and α-tocopherol increase with time of extraction; the optimum time was determined. Results obtained in this work show that, for both oxidative stability and antioxidant capacity, TPC have a more important role then α-tocopherol.     

Toxic Compound,Anti-Nutritional Factors and Functional Properties of Protein Isolated from Detoxified Jatropha curcas Seed Cake

Jatropha curcas is a multipurpose tree, which has potential as an alternative source for biodiesel. All of its parts can also be used for human food, animal feed, fertilizer, fuel and traditional medicine. J. curcas seed cake is a low-value by-product obtained from biodiesel production. The seed cake, however, has a high amount of protein, with the presence of a main toxic compound: phorbol esters as well as anti-nutritional factors: trypsin inhibitors, phytic acid, lectin and saponin. The objective of this work was to detoxify J. curcas seed cake and study the toxin, anti-nutritional factors and also functional properties of the protein isolated from the detoxified seed cake. The yield of protein isolate was approximately 70.9%. The protein isolate was obtained without a detectable level of phorbol esters. The solubility of the protein isolate was maximal at pH 12.0 and minimal at pH 4.0. The water and oil binding capacities of the protein isolate were 1.76 g water/g protein and 1.07 mL oil/g protein, respectively. The foam capacity and stability, including emulsion activity and stability of protein isolate, had higher values in a range of basic pHs, while foam and emulsion stabilities decreased with increasing time. The results suggest that the detoxified J. curcas seed cake has potential to be exploited as a novel source of functional protein for food applications.     

Tocopherol oil concentration in field-grown sunflower is accounted for by oil weight per seed

Tocopherols are natural antioxidants that increase the stability of fat-containing foods and perform important biological activities. Significant variations (389 to 1873 μg g oil⁻¹) in the total tocopherol concentration of sunflower seed oil have been reported. The main objectives of this work were to determine the influence of intercepted photosynthetically active radiation on tocopherol concentration during seed filling and to establish and validate relationships between tocopherol concentration in oil and other quality variables of the seed. Seven sunflower hybrids were grown under good water and nutritional conditions in two similar experiments carried out in two contrasting environments. Treatments were applied to modify the amount of radiation intercepted per plant during seed filling in order to obtain a range in oil yield per plant and its components. Greater per plant intercepted radiation decreased the tocopherol concentration in oil. Tocopherol concentration decreased when oil weight per seed increased. Tocopherol concentration stabilized for oil weight per seed higher than 23 mg oil seed⁻¹. This exponential relationship accounted for 73% of the variability in tocopherol concentration (507 to 1203 μg g oil⁻¹) despite differences in hull type, locations, hybrids, and radiation treatments. The proposed relationship acceptably predicted independent results. Crop management techniques could lead to seeds with greater concentrations of tocopherols.     

Tocopherols and tocotrienols in grape seeds from 14 cultivars grown in Korea

In this study, the tocopherol (T) and tocotrienol (T3) contents of grape seeds from 14 different varieties grown in Korea were analyzed using saponification extraction followed by normal‐phase liquid chromatography. α‐T, γ‐T, α‐T3, and γ‐T3 were detected in all samples. The total concentration of tocopherol and tocotrienol was in the range of 4.8–9.9 mg/100 g seed (35.3–68.8 mg/100 g oil basis). The Muscat Bailey A cultivar had the highest total tocopherol and tocotrienol contents, followed by Canner and Naples. γ‐T3 ranged from 1.6 to 4.9 mg/100 g seed (11.2 to 53.81 mg/100 g oil basis) and was the main isomer, followed by α‐T3 in most of the samples. Analytical method validation parameters including accuracy and precision were determined. Overall recovery from grape seeds was close to 100%.     

Composition and physicochemical properties of Combretum collinum,Combretum micranthum,Combretum nigricans,and Combretum niorense seeds and seed oils from Burkina Faso

Combretum collinum, Combretum micranthum, Combretum nigricans, and Combretum niorense are abundant unconventional seed oils of the African savannah. In this study, the proximate, mineral, amino acid, fatty acid, and triacylglycerol compositions of the four seed oils were quantified, and the oxidative and physicochemical properties were investigated. The amino acid, fatty acid, and triacylglycerol compositions were determined by using high performance liquid chromatography (HPLC) and gas chromatography respectively. Carbohydrates (57.35%–64.20%) followed by crude oils (20.07%–22.60%), proteins (11.95%–15.86%), and ashes (3.78%–6.19%) were the main constituents of the four seed species. The highest ash, crude fat, and protein contents were found in C. collinum, C. nigricans, and C. niorense, respectively. All four seed species were rich in Ca, K and Mg, and poor in methionine, cysteine, and lysine. The four seed oils had high saponification values (198.46–202.71 mgKOH/g), low acidity (1.12–2.26 mg of KOH/g of oil), and peroxide values (1.19–1.98 mEqO₂/kg of oil). The seed oils of C. micranthum and C. collinum exhibited the highest thermal oxidative stability (8.10 and 9.79 h at 160°C). Oleic (40.49%–56.69%), palmitic (15.17%–24.27%) and linoleic (9.49%–14.50%) acids were the predominant fatty acids of the four seed oils. The results showed that the four seed species and seed oils had good chemical composition and physicochemical properties making them suitable for food and non-food application.     

Lignan contents in sesame seeds and products

Sesame seed (Sesamum indicum L.) is a rich source of furofuran lignans with a wide range of potential biological activities. The major lignans in sesame seeds are the oil‐soluble sesamin and sesamolin, as well as glucosides of sesaminol and sesamolinol that reside in the defatted sesame flour. Upon refining of sesame oil, acid‐catalyzed transformation of sesamin to episesamin and of sesamolin to epimeric sesaminols takes place, making the profile of refined sesame oils different from that of virgin oils. In this study, the total lignan content of 14 sesame seeds ranged between 405 and 1178 mg/100 g and the total lignan content in 14 different products, including tahini, ranged between 11 and 763 mg/100 g. The content of sesamin and sesamolin in ten commercial virgin and roasted sesame oils was in the range of 444–1601 mg/100 g oil. In five refined sesame oils, sesamin ranged between 118 and 401 mg/100 g seed, episesamin between 12 and 206 mg/100 g seed, and the total contents of sesaminol epimers between 5 and 35 mg/100 g seed, and no sesamolin was found. Thus, there is a great variation in the types and amounts of lignans in sesame seeds, seed products and oils. This knowledge is important for nutritionists working on resolving the connection between diet and health. Since the consumption of sesame seed products is increasing steadily in Europe and USA, it is important to include sesame seed lignans in databases and studies pertinent to the nutritional significance of antioxidants and phytoestrogens. It is also important to differentiate between virgin, roasted and refined sesame oils.     

超临界二氧化碳萃取葡萄籽油工艺优化

为了回收利用葡萄酒酿造过程产生的副产品中的有效成分,本文利用超临界CO₂萃取技术从葡萄籽中提取含有不饱和脂肪酸的葡萄籽油,意在考量超临界CO₂技术在萃取葡萄籽油方面的作用。设计单因素实验,研究了萃取压力、萃取温度、CO₂流量以及停留时间对葡萄籽油萃取率的影响。单因素实验结果表明萃取压力对萃取结果的影响最为显著。萃取温度和CO₂流量对萃取率的影响都存在最佳值,当温度和流量超过最佳值,萃取率开始降低。在单因素实验的基础上进行响应面实验,采用中心复合设计进行实验方案设计以优化萃取葡萄籽油工艺。对响应面实验结果进行方差分析,建立多元回归模型,模型P值<0.0001,预测超临界CO₂萃取葡萄籽油的最佳萃取条件为：萃取压力28MPa、萃取温度321 K、CO₂流量15.5L/h,停留时间155min,萃取率达到14.12%。