Distribution of fatty acids and phytosterols as a criterion to discriminate geographic origin of pistachio seeds

The composition of fatty acids and phytosterols was investigated in the oil extracted from the pistachio seeds coming from different countries, (Italy, Turkey, Iran and Greece). The oils are characterized by high contents of oleic acid and β-sitosterol, showing a composition almost similar to that of olive oil. The pattern recognition of data for fatty acids sterols, by multivariate analyses, may provide useful criteria for origin authentication of pistachio seeds.     

Walnut (Juglans regia L.): genetic resources,chemistry, by‐products

Walnut (Juglans regia L.) is the most widespread tree nut in the world. There is a great diversity of genotypes differing in forestry, productivity, physical and chemical nut traits. Some of them have been evaluated as promising and may serve as germplasm sources for breeding. The nutritional importance of the nut is related to the seed (kernel). It is a nutrient‐dense food mainly owing to its oil content (up to 740 g kg^?1 in some commercial varieties), which can be extracted easily by screw pressing and consumed without refining. Walnut oil composition is dominated largely by unsaturated fatty acids (mainly linoleic together with lesser amounts of oleic and linolenic acids). Minor components of walnut oil include tocopherols, phospholipids, sphingolipids, sterols, hydrocarbons and volatile compounds. Phenolic compounds, present at high levels in the seed coat but poorly extracted with the oil, have been extensively characterised and found to possess strong antioxidant properties. The oil extraction residue is rich in proteins (unusually high in arginine, glutamic and aspartic acids) and has been employed in the formulation of various functional food products. This review describes current scientific knowledge concerning walnut genetic resources and composition as well as by‐product obtainment and characteristics. Copyright © 2010 Society of Chemical Industry     

Chemical Properties and Oxidative Stability of Perilla Oils Obtained From Roasted Perilla Seeds As Affected by Extraction Methods

Abstract: The chemical properties and oxidative stability of perilla oils obtained from roasted perilla seeds as affected by extraction methods (supercritical carbon dioxide [SC‐CO₂], mechanical press, and solvent extraction) were studied. The SC‐CO₂ extraction at 420 bar and 50 °C and hexane extraction showed significantly higher oil yield than mechanical press extraction (P < 0.05). The fatty acid compositions in the oils were virtually identical regardless of the extraction methods. The contents of tocopherol, sterol, policosanol, and phosphorus in the perilla oils greatly varied with the extraction methods. The SC‐CO₂‐extracted perilla oils contained significantly higher contents of tocopherols, sterols, and policosanols than the mechanical press‐extracted and hexane‐extracted oils (P < 0.05). The SC‐CO₂‐extracted oil showed the greatly lower oxidative stability than press‐extracted and hexane‐extracted oils during the storage in the oven under dark at 60 °C. However, the photooxidative stabilities of the oils were not considerably different with extraction methods.     

Supercritical CO2 extraction of fatty oil from flaxseed and comparison with screw press expression and solvent extraction processes

Flax oil is commonly used in food due to high percentage of omega-3-fatty acid and omega-6-fatty acid. In the present work the flax seed was extracted using green solvent viz. supercritical CO₂ and compared with soxhlet and mechanical screw press methods. The chemical compositions of the oils were determined by CHNS analyser, GC-FID, GC/MS and ¹H NMR. The supercritical CO₂ process selectively extracted the fatty oils with high percentage of omega-3-fatty acid and omega-6-fatty acids. The chemical composition of screw press oil is close to that of supercritical CO₂ extracted oil, whereas the yield is nearly 27% less in comparison to the supercritical CO₂ method.     

Supercritical CO<Subscript>2</Subscript> extraction in chia oils production: impact of process duration and co-solvent addition

This study was conducted to show impact of supercritical fluid extraction using pure SC-CO₂ or SC-CO₂ enriched by 2, 6, and 10% of acetone, simultaneously varied by the extraction time (1 vs. 5 h), on the quality of chia seed oils. Obtained oils were relatively similar in the fatty acid composition, but they differed in total content of phytochemicals (from 4956 to 6391 mg/kg of oil). Among them, three oils were the most different: oil extracted 1 h with pure SC-CO₂ (the most abundant in squalene, sterols, and tocopherols), oil extracted 5 h with pure SC-CO₂ (the poorest in squalene, polyphenols, and carotenoids, with medium level of sterols and tocopherols) and oil extracted 1 h with SC-CO₂ enriched by 10% acetone (the most abundant in polyphenols and carotenoids). Such unique chia oils can be valuable for special market needs, such as cosmetics, pharmaceuticals, functional food or diet supplement production.     

核桃油与常用植物油中37种脂肪酸和角鲨烯含量比较

为探明核桃油与大豆油、芝麻油和玉米胚芽油等常用植物油的营养价值差异,本研究采用气-质联用法和气相色谱法对4种植物油中37种脂肪酸和角鲨烯的含量进行了测定,并开展了对比分析。结果表明,核桃油与常用植物油营养价值存在显著差异（P<0.05）,核桃油富含α-亚麻酸、二十碳二烯酸和亚油酸3种多不饱和脂肪酸以及油酸等单不饱和脂肪酸,还含有少量的棕榈酸及硬脂酸等饱和脂肪酸,核桃油中多不饱和脂肪酸组成与比例显著高于其他植物油（P<0.05）,而饱和脂肪酸则显著低于其他植物油（P<0.05）;核桃油中角鲨烯含量略低于芝麻油,属于优质植物油。4种植物油中总脂肪酸含量从高到低顺序依次为大豆油、芝麻油、核桃油和玉米胚芽油,含量分别为78.11、73.96、69.20和48.83 g/100 g;4种植物油均含α-亚麻酸、亚油酸和二十碳二烯酸等人体必需脂肪酸（Essential fatty acids,EFA）,EFA含量从高到低依次为核桃油、大豆油、玉米胚芽油和芝麻油,分别占总脂肪酸的90.0%、70.7%、64.9%和54.1%;4种植物油的油酸含量与亚油酸含量的比值（油亚比R）由高到低依次为芝麻油、玉米胚芽油、大豆油和核桃油,分别为0.62、0.35、0.27和0.10,表明4种植物油中,芝麻油的抗氧化能力最大,可保存时间最长。大豆油、核桃油和芝麻油中均检出角鲨烯,其含量从高到低依次为大豆油、芝麻油和核桃油,含量分别为173.3、72.9和31.4 mg/kg,玉米胚芽油中仅含有微量的角鲨烯,未检出。本研究表明不同植物油中脂肪酸及角鲨烯等营养物质含量存在差异,可为食用植物油的营养价值分析、相关的食品和保健品等产品研发提供科学依据。     

Antioxidant activity of minor components of tree nut oils

The antioxidative components of tree nut oils were extracted using a solvent stripping process. Tree nut oil extracts contained phospholipids, sphingolipids, sterols and tocopherols. The chloroform/methanol extracted oils had higher amounts of phenolic compounds than their hexane extracted counterparts. The antioxidant activity of tree nut oil minor component extracts were assessed using the 2,2-azino-bis (3-ethylbenzthiazoline sulphonate) (ABTS) radical scavenging activity, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity, β-carotene bleaching test, oxygen radical absorbance capacity (ORAC) and photochemiluminescence inhibition assays. Results of these studies demonstrated that extracts of chloroform/methanol extracted oils possessed higher antioxidant activities than extracts of their hexane extracted counterparts. Meanwhile the extract of chloroform/methanol extracted pecan oil possessed the highest antioxidant activity.     

Fatty Acids,Sterols, Polyphenols,and Chlorophylls of Olive Oils Obtained from Tunisian Wild Olive Trees (Olea europaea L. Var. Sylvestris)

Olive (Olea europaea L.) includes cultivated olive trees (var. europaea) and wild olive trees or oleaster (var. sylvestris) as two botanical varieties. These olive varieties were widely spread in the Mediterranean Region. The aim of this study was to determine fatty acid compositions, sterols, polyphenols, and chlorophylls of oils obtained from 12 wild olive trees from Northern Tunisia. Two dominated oil cultivars in Tunisia (Chétoui and Chemlali) were also used to compare results. The fatty acid methyl ester and the sterol compositions were analyzed using gas-liquid chromatography and thin layer chromatography methods, respectively. The polyphenols and chlorophylls were determined using the calorimetrical method. Results indicated that oils extracted from wild olives displayed good balanced fatty acid compositions, sterols, polyphenols, and chlorophylls. Qualitatively, for wild and cultivated olive oils, the oil has an identical composition, whereas the quantitative variation showed that some wild trees seem to be interesting oil sources as two Tunisian dominated cultivars. The highest oleic acid and polyphenol contents were 71.55% and 537.6 mg/kg of oil found in wild olives (OIch2, OIch1). The β-sitosterol was the major sterolic fraction and ranged from 84.72 to 75.70% according to the wild olives. Consequently, wild olives would be a new future edible olive oil source, as well as commonly cultivated ones.     

Comparison between free radical scavenging capacity and oxidative stability of nut oils

Several works have measured free radical scavenging capacity of nut oils, since they may become a significant source of dietary fat. However, they have not considered kinetic parameters, what was the first aim of this work. Also, it was studied the possible relation between values of free radical scavenging capacity DPPH and oxidative stability (Rancimat method) in different nut (hazelnut, peanut, pistachio, walnut and almond) oils. The ranking of antioxidant capacity of nut oils, by both assays, was: pistachio > hazelnut > walnut > almond > peanut. A significant correlation was found between DPPH and Rancimat methods assays. Tocopherols appear to be the responsible compounds of this antioxidant capacity being neglictible the contribution of polyphenols. An interference effect of phospholipids, present in methanolic fraction of nut oils, was observed in the determination of polyphenols in nut oils by Folin and ortho-diphenols assays.     

芝麻品种和制油工艺对芝麻油品质的影响

对以黑、白芝麻为原料,采用水代法、螺旋压榨法、液压压榨法工艺所得芝麻油的理化指标、脂肪酸组成、芝麻油中VE、芝麻素、芝麻酚含量和氧化稳定性进行了测定。结果显示:水代法所得芝麻油的酸值(KOH)和磷脂含量最低,而水分及挥发物含量最高;所有芝麻油样品均含有丰富的抗氧化成分芝麻素、芝麻酚和VE;所有芝麻油样品的脂肪酸组成接近,其中油酸和亚油酸含量高达83.4%;白芝麻油氧化稳定性明显优于黑芝麻油,水代法所得芝麻油氧化稳定性最好,液压压榨芝麻油次之,螺旋压榨芝麻油最差。     

Essential oil,fatty acid and sterol composition of Tunisian coriander fruit different parts

BACKGROUND: Seed and pericarp of coriander fruit were compared in terms of essential oil, fatty acids and sterols. RESULTS: Essential oil yield of coriander samples ranged from 0.30 to 0.68% (w/w) in fruit and seed, respectively. However, in pericarp, the essential oil yield was only of 0.04% (w/w). Linalool was the major compound in the whole fruit, seed and pericarp, with 86.1%, 91.1% and 24.6% of the oils, respectively. Fatty acid composition of pericarp and seed lipids were investigated by gas chromatography. Petroselinic acid was the main compound of fruit and seed, followed by linoleic and oleic acids. Palmitic and linoleic acids were estimated in higher amounts in pericarp lipids. Total sterol contents were 36.93 g kg^?1 oil in seed, 6.29 g kg^?1 oil in fruit and 4.30 g kg^?1 oil in pericarp. Fruit and pericarp oils were characterized by a high proportion of β‐sitosterol, with 36.7% and 49.4% of total sterols, respectively. However, stigmasterol (29.5%) was found to be the sterol marker in seed oils. CONCLUSION: Coriander oil is a rich source of many compounds such as essential oils, fatty acids and sterols. This compound distribution presented significant differences between whole fruit, seed and pericarp. Copyright © 2009 Society of Chemical Industry     

改良的DPPH与ABTS自由基法评价不同葡萄籽油抗氧化能力

本研究采用改良的1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picryhydrazyl,DPPH)法和2,2'-联氮双-(3-乙基苯并噻唑林-6-磺酸)二胺盐[2,2'-azinobis(3-ethylbenzothi azoline-6-sulfonic acid)ammonium salt,ABTS]法测定不同方法提取葡萄籽油极性部分、非极性部分及全油的抗氧化能力,测定不同葡萄籽油多酚含量,研究多酚与葡萄籽油极性部分抗氧化能力的相关性。热榨毛油与溶剂法毛油在经过精炼后多酚含量和抗氧化能力显著降低;在溶剂法精炼油、热榨法精炼油、低温压榨油、超临界CO_2萃取葡萄籽油中,低温压榨油极性部分清除DPPH与ABTS自由基的能力最强,低温压榨油的多酚含量最高,超临界CO_2萃取葡萄籽油非极性部分与低温压榨油全油的DPPH与ABTS自由基清除能力最强;各不同葡萄籽油总酚含量与极性部分DPPH和ABTS自由基的清除能力具有显著的正相关性。     

不同工艺制备核桃油品质比较及相关性分析

对溶剂提取、低温压榨两种方法提取的核桃油感官品质(色泽)、理化营养品质(水分及挥发物含量、脂肪酸组成、VE异构体含量、植物甾醇各组分含量)及加工品质(诱导时间、过氧化值、酸值、脂肪酸比例模式)进行测定并对其品质指标进行相关性分析。结果表明:低温压榨核桃油的加工品质较好,其诱导时间(1.92 h)较长,过氧化值(1.44 mmol/kg)和酸值(KOH)(0.69 mg/g)较低,且O/L(0.33)较高;其油酸含量(19.97%)及UFA含量(90.96%)较高,营养品质相对较好。色泽与诱导时间呈极显著正相关;油酸含量与亚油酸含量呈极显著负相关(r=-0.944);油酸、亚油酸、MUFA、PUFA、O/L与诱导时间的相关关系均达到极显著水平。     

RANCIDITY OF WALNUTS AND ALMONDS AFFECTED BY SHORT TIME HEAT TREATMENTS FOR INSECT CONTROL

Short time heat treatments effectively control insect contamination of nuts containing substantial quantities of polyunsaturated fatty acids susceptible to oxidative rancidity. Walnut kernels contain greater concentrations of polyunsaturated fatty acids than almond kernels. The objectives of this research were to investigate the lipid stability of shelled walnuts and almonds as affected by short time heat treatments and accelerated storage temperatures. Heating treatments were at 55C for 2 min, 55C for 10 min, 60C for 2 min or 60C for 10 min to simulate predetermined deinfestation treatments. Untreated control and heat treated shelled walnut and almond kernels were stored at 25C for 5, 15, 30 and 60 days or 35C for 2, 5, 10 and 20 days to simulate the shelf lives of walnut and almond kernels at 4C for 2 years. Oils extracted from untreated and short time heat treated walnut kernels exhibited higher peroxide values than oils extracted from untreated and short time heat treated almond kernels under equivalent conditions. Oils extracted from untreated walnut kernels exhibited significantly (P ± 0.05) higher peroxide values than oils extracted from short time heat treated walnut kernels after 5, 15, 30, and 60 days of storage at 25C, or after 2, 5, 10, or 20 days of storage at 35C. Oils extracted from untreated almond kernels exhibited higher peroxide values than oils extracted from short time heat treated almond kernels after 5, 15, 30, or 60 days of storage at 25C, or after 2, 5, 10 or 20 days of storage at 35C. Oils extracted from untreated walnut kernels and oils extracted from short time heat treated walnut kernels exhibited higher peroxide values than oils extracted from almond kernels after storage at 25C or 35C. Short time heat treatment does not enhance development of rancidity during accelerated storage of walnut or almond kernels.     

美藤果油、亚麻籽油和紫苏籽油氧化稳定性对比研究

以共轭二烯烃、共轭三烯烃、过氧化值、羰基值平均增长速率以及110℃的氧化诱导时间为指标,对比研究了美藤果油、亚麻籽油和紫苏籽油的氧化稳定性,同时探讨了在60℃加速氧化过程中3种植物油主要微量组分以及脂肪酸组成的变化。结果表明:3种植物油中共轭二烯烃、共轭三烯烃、过氧化值、羰基值平均增长速率为美藤果油<亚麻籽油<紫苏籽油,氧化诱导时间为美藤果油>亚麻籽油>紫苏籽油;甾醇、多酚的损失率为紫苏籽油>美藤果油>亚麻籽油,维生素E的损失率为紫苏籽油>亚麻籽油>美藤果油;多不饱和脂肪酸损失率和饱和脂肪酸增加率为亚麻籽油>紫苏籽油>美藤果油。因此,认为美藤果油氧化稳定性最强,亚麻籽油次之,紫苏籽油最弱。     

Effects of different nut oils on the structures and properties of gel-like emulsions induced by ultrasound using soy protein as an emulsifier

Gel-like emulsions were produced by high-intensity ultrasound (HIU) emulsification using soy protein as an emulsifier. Sunflower (a seed kernel oil), peanut (a groundnut oil), hazelnut, walnut, almond and pine nut oils were chosen as oil phases. The kinds of nut oil significantly affect the structures and properties of gel-like emulsions. The particle size of sunflower oil gel-like emulsion was smallest. Moreover, the macrorheological and microrheological results indicated that the values of apparent viscosity, storage modulus (G′) and elasticity index (EI) of sunflower and almond oil gel-like emulsions were higher while those of the walnut and pine nut oil gel-like emulsions were lower. Moreover, the sunflower oil gel-like emulsion was more stable after 2-month storage. The current study illustrated that HIU was of great importance for the production of high-viscosity gel-like emulsions. Furthermore, the differences of nut oils resulted in diverse physicochemical properties of gel-like emulsions.     

Effect of chronic consumption of pistachios (Pistacia vera L.) on glucose metabolism in pre-diabetics and type 2 diabetics: A systematic review

Pistachio is a nut with high polyunsaturated fatty acids (PUFA), monounsaturated fatty acids (MUFA), polyphenols and carotenoids content, and the synergism between these compounds appears to affect glucose metabolism. In this systematic review we analyzed studies in which the effect of chronic consumption of pistachio on markers of glucose metabolism was evaluated in pre-diabetic and type 2 diabetics. We used the PubMed, Scopus, Cochrane and Lilacs databases. The research terms used were pistachio, pre-diabetes, type 2 diabetes mellitus, insulin resistance, blood glucose, hyperglycemia and glycated hemoglobin (HbA1c). Four articles were selected, of which three tested the intake of 50 to 57 g of pistachio/day and one 20% of the daily caloric intake, for a period of 1 to 4 months. Studies reported a decrease in fasting blood glucose, insulinemia, HOMA-IR, and fructosamine, but no change in HbA1c. Lower concentrations of miR-192 and miR-375 were also found, which correlated positively with HOMA-IR. The synergism between PUFA, MUFA, polyphenols and carotenoids present in pistachios can modulate specific miRNA, increasing insulin sensitivity through the PI3K-AKT signaling pathway. This modulation can be used as a tool to monitor the response to interventions, favoring the prevention and treatment of complications related to diabetes.     

内种皮色泽及其热烫脱除对压榨核桃油品质的影响

内种皮色泽是核桃仁等级划分的重要标准之一。本实验研究了内种皮色泽及其热烫脱除对压榨核桃油颜色、营养成分和稳定性的影响。结果表明：内种皮色泽对压榨油颜色的影响不显著（P＞0.05）,且去皮处理对压榨油颜色无影响。营养成分上,深色仁油与浅色仁油在不饱和脂肪酸、总酚及生育酚含量上均无显著性差异;去皮处理对两者的不饱和脂肪酸含量无明显影响,但会导致生育酚总量的显著下降,深色仁油、浅色仁油生育酚总量分别降低20.19%、16.33%。而去皮前后核桃油中总酚含量均很少,主要存在于压榨粕中。稳定性方面,深色仁油与浅色仁油无显著差异;去皮后,两者的氧化诱导期分别缩短0.68、0.53 h,60 ℃货架期分别缩短5.52、3.36 h。另外,研究还发现内种皮的存在可提高核桃仁的压榨出油率,去皮后深色仁与浅色仁的出油率分别降低5.43%、3.29%。     

Physicochemical properties and bioactive compounds of selected seed oils

The physicochemical properties and chemical composition of oil extracted from five varieties of plant seeds (bittermelon, Kalahari melon, kenaf, pumpkin and roselle seeds) were examined by established methods. The thermal properties of extracted oils by differential scanning calorimetry were also evaluated. Sensorial profiles of these seed oils were defined through the CieLab (L*, a*, b*) colour. Most of the quality indices and fatty acid compositions showed significant (P < 0.05) variations among the extracted oils. Physicochemical properties of the oils extracted were iodine value, 86.0-125.0 g I₂/100 g oil; saponification value, 171.0-190.7 mg of KOH/g of oil; acid value, 1.1-12.9 mg of KOH/g of oil, free fatty acid, 0.6-6.5 g/100 g of oil, and peroxide value 1.5-6.5 meq of O₂/kg of oil. Palmitic, oleic and linoleic acids were the major fatty acids in all of the extracted seed oils except for bittermelon, where eleostearic acid was the major fatty acid. Gallic, protocatechuic, p-hydroxybenzoic, vanillic, caffeic, syringic, p-coumaric and ferulic acids were identified in the extracted plant oils. Among these, vanillic acid was predominant in all extracted oils. The oils were rich in tocopherols with γ-tocopherol as the major components in all oil samples. Among the phytosterols, sitosterol was the major phytosterol extracted from the five plant seed oils. The seeds of these plants contain a great number of valuable minor compounds, which have a potential high value as food and for production of non-food products.     

新疆4种典型木本油料油脂脂肪酸和甘三酯组成分析

以新疆4种典型的木本油料沙漠果、碧根果、甜杏仁和巴旦木为原料,测定了4种木本油料种仁的粗脂肪含量、水分及挥发物含量,以及4种油脂的脂肪酸和甘三酯组成。结果表明:4种油料种仁的水分及挥发物含量较低,粗脂肪含量较高,为40. 67%～69. 29%;巴旦木油、碧根果油和甜杏仁油不饱和脂肪酸含量均在90%以上,沙漠果油的不饱和脂肪酸含量为73. 85%; 4种油脂的脂肪酸均以油酸为主(48. 04%～80. 16%);巴旦木油、碧根果油和甜杏仁油以三不饱和脂肪酸甘油酯为主,含量为69. 88%～75. 50%,沙漠果油以二不饱和脂肪酸甘油酯为主,含量为48. 50%; 4种油脂甘三酯均以OOO最多,碳原子当量中均以ECN48最高。