南瓜籽油的水酶法提取工艺及产品的理化性质

为提高南瓜籽油的出油率和出油品质,采用水酶法建立南瓜籽油提取工艺,通过单因素试验和正交试验优化提取工艺条件,并对南瓜籽油的理化性质和主要营养组分进行了分析。研究结果表明,水酶法提取南瓜籽油的较佳工艺条件为：复合酶配比1∶6∶6（酸性蛋白酶∶纤维素酶∶果胶酶）、复合加酶量1.2%、酶解pH值为4.0、酶解温度48℃、酶解时间3 h,南瓜籽出油率为38.34%。对比超临界CO2提取法出油率32.90%和超声波溶剂法出油率44.60%,使用水酶法出油率较高,所提取的南瓜籽油色泽明亮,澄清透明,富含不饱和脂肪酸、植物甾醇和维生素E等营养成分,其理化性质优于其他2种方法提取的油脂,各项指标均达到了国家食用油标准,是具有特殊功能的营养保健油源。     

Chemical composition and antioxidant properties of clove leaf essential oil

The antioxidant activity of a commercial rectified clove leaf essential oil (Eugenia caryophyllus) and its main constituent eugenol was tested. This essential oil comprises in total 23 identified constituents, among them eugenol (76.8%), followed by beta-caryophyllene (17.4%), alpha-humulene (2.1%), and eugenyl acetate (1.2%) as the main components. The essential oil from clove demonstrated scavenging activity against the 2,2-diphenyl-1-picryl hydracyl (DPPH) radical at concentrations lower than the concentrations of eugenol, butylated hydroxytoluene (BHT), and butylated hydroxyanisole (BHA). This essential oil also showed a significant inhibitory effect against hydroxyl radicals and acted as an iron chelator. With respect to the lipid peroxidation, the inhibitory activity of clove oil determined using a linoleic acid emulsion system indicated a higher antioxidant activity than the standard BHT.     

微胶囊双水相提取柑桔精油的工艺优化

为寻找一条适合工业化生产的低成本、低能耗、高效率的柑桔精油提取工艺路线,该文采用微胶囊与双水相联合萃取技术提取柑桔精油。结果表明：通过调整β-环糊精和硫酸钠的浓度比,可有效控制囊化萃取物中柑桔精油的质量。最终由正交试验设计确定出柑桔精油在萃取温度30℃、硫酸钠浓度15%、β-环糊精浓度40%、萃取时间30 min的条件下总收率高达96%以上。     

Antioxidant properties and composition of aqueous extracts from Mentha species, hybrids, varieties, and cultivars

Water-soluble extracts from the Mentha species M. aquatica L. and M. haplocalyx Briq., the hybrids M. x dalmatica L. and M. x verticillata L., the varieties M. arvensis var. japanensis [M. arvensis L. var. piperascens Holmes ex Christ] and M. spicata L. var. crispa Benth, and M. x piperita L. "Frantsila", M. "Morocco", and M. "Native Wilmet" cultivars were screened for potential antioxidative properties. These properties included iron(III) reduction, iron(II) chelation, 1,1-diphenyl-2-picrylhydrazyl radical scavenging, and the ability to inhibit iron(III)-ascorbate-catalyzed hydroxyl radical-mediated brain phospholipid peroxidation. Total phenol content and qualitative and quantitative compositional analyses of each extract were also made. The extracts demonstrated varying degrees of efficacy in each assay, with the M. x piperita "Frantsila" extract being better than the other extracts, except for ferrous iron chelation. With the exception of iron chelation, it appeared that the level of activity identified was strongly associated with the phenolic content.     

肉桂油/海藻酸钠薄膜物理特性和抗菌性能分析

为了研究开发新型可降解抗菌包装材料,该文以添加不同体积肉桂油到海藻酸钠膜液中制成的肉桂油/海藻酸钠抗菌薄膜为研究对象,比较分析肉桂油添加量对肉桂油/海藻酸钠薄膜厚度、透光率、色泽和水蒸气透过率等物理特性的影响,同时,考察其对薄膜的抗菌性能的影响。膜液中肉桂油体积分数在0～1.0%时,薄膜厚度无明显变化,体积分数为1.2%时,薄膜厚度显著增加。随着肉桂油体积分数的增加,薄膜的透光率显著降低,薄膜水蒸气透过系数增大。肉桂油对薄膜色泽影响显著,随着肉桂油添加量的增加,薄膜色泽值a和b呈显著增加趋势。膜液中肉桂油体积分数为0.8%时,薄膜抗菌能力显著增强。研究结果表明,当膜液中肉桂油体积分数为0.8%时,薄膜具有较好的抗菌效果和物理性能。该研究可为肉桂油/海藻酸钠可降解抗菌薄膜生产工艺参数的进一步优化提供参考。     

Fatty acid composition of oil crops: genetics and genetic engineering

Genetic Resources and Crop Evolution - Vegetable oils are important components of the human diet, and are also actively used for industrial and cosmetic purposes and as biofuels. The scope of oil...     

O/W emulsification for the self-aggregation and nanoparticle formation of linoleic acid-modified chitosan in the aqueous system

Chitosan was modified by coupling with linoleic acid through the 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide-mediated reaction to increase its amphipathicity for improved emulsification. The micelle formation of linoleic acid-modified chitosan in the 0.1 M acetic acid solution was enhanced by O/W emulsification with methylene chloride, an oil phase. The fluorescence spectra indicate that without emulsification the self-aggregation of LA-chitosan occurred at the concentration of 1.0 g/L or above, and with emulsification, self-aggregation was greatly enhanced followed by a stable micelle formation at 2.0 g/L. The addition of 1 M sodium chloride promoted the self-aggregation of LA-chitosan molecules both with and without emulsification. The micelles of LA-chitosan formed nanosize particles ranging from 200 to 600 nm. The LA-chitosan nanoparticles encapsulated the lipid soluble model compound, retinal acetate, with 50% efficiency.     

Variation in seed oil composition of species from the genera Barbarea and Lepidium

The seed oil composition and content in a number of accessions from species of the genera Barbarea and Lepidium were analysed. The oil from most accessions of B. verna contained more than 50% erucic acid, while the oil from B. vulgaris contained ～ 30% erucic acid, and 22% each of oleic and linoleic acid. The oil from B. intermedia resembled that of B. verna. The oil content was ～ 30% in all three species. The oil composition of L. campestre and L. heterophyllum is ～ 35% linolenic acid and 23% erucic acid. Other Lepidium species had up to 47% linolenic acid in the oil. The oil content of L. campestre and L. heterophylhim was just below 20%, but other species had more than 30% oil in their seeds. The variation in oil composition found within and between species is considered sufficient for the breeding of valuable oil qualities in both genera.     

Characterization of the chemical composition of lotus plumule oil

Characterizations of lotus plumule and plumule oil, focusing on approximate composition analysis of lotus plumule powder and fatty acid composition, lipid classes, triglyceride (TG) profiles, and sterol analysis of the plumule oil, were conducted in this work. The results revealed that the lotus plumule constitutes 7.8% moisture, 4.2% ash, and 12.5% crude oil and 26.3% protein on the dry base. Lotus plumule oil is rich in linoleic acid (50.4%) and oleic acid (13.5%), and the dominating saturated fatty acids are palmitic acid (18.0%) and behenic acid (6.8%). The principal components of TG in lotus plumule oil are LLL (12.80%), beta-PLL (11.27%), beta-POL (8.28%), beta-PLO (8.58%), and beta-BeLL (8.32%). Lipid class assay of the crude oil gave the saponification value of 153.4 KOH mg/g and tocopherol content 390 mg/100 g. A distinct characteristic of lotus plumule oil is that its unsaponifiable matter is incredibly high, up to 14-19%, which consists mainly of beta-sitosterol (32%), Delta(5)-avenasterol (20%), and campesterol (6.3%). The major occurring form of sterols was found to be steryl ester. This work might be useful to develop innovative applications of lotus plumule oil.     

Epiphytic bacterial complexes in grain crops: Taxonomic composition and antagonistic properties

It is shown that the taxonomic composition of epiphytic bacteria on the leaves of wheat and barley changes in the course of vegetation. Pseudomonas and Arthrobacter predominated on young leaves and were later replaced with the ageing of the leaves by bacteria of the hydrolytic block: myxobacteria and bacilli. Representatives of myxobacteria were found as dominants on grains in wheat and barley ears as well. Thus, the replacement of eccrisotrophs, which feed on plant excreta, with the bacteria of the hydrolytic block, which are capable of destroying dying plant tissues, was observed in the phyllosphere. Bacteria of the same taxa as those from the phyllosphere of the studied crops were isolated from the rhizosphere and the soil, where only the fraction of typical pedobionts increased, such as bacilli, Arthrobacter, and Rhodococci. It was established that the bacteria that prevail on the studied agricultural plants possess antibiotic activity toward three species of phytopathogenic bacteria used in the experiment, which indicates the protective role of epiphytic prokaryotes toward host plants.     

Soybean oil based greases: influence of composition on thermo-oxidative and tribochemical behavior

The biodegradable properties and lubricating ability of greases depend on both the base oil and the thickener. Mineral oils are the most widely used lubricant base fluids due to their inherent lubricity and low cost, but recent environmental awareness has forced consideration of the use of biodegradable fluids such as vegetable oils and certain synthetic fluids in grease formulations. This study presents data on the thermo-oxidation behavior and tribology of biodegradable greases formulated with soybean oil and different compositions of metal soap thickener. The composition of thickener has been varied by using fatty acids with different degrees of unsaturation and fatty acids of different chain lengths. The improvement of thermo-oxidation and tribological properties as a result of changing thickener/base oil ratio and the antioxidative effect of some suitable additives have also been evaluated.     

水相酶解法提取菜籽油与菜籽蛋白工艺的优化

为提高菜籽蛋白的利用率，采用水相酶解法提取菜籽油与菜籽蛋白，以超滤法分离菜籽蛋白，重点对酶处理的工艺参数进行了研究。试验对各种酶的作用效果进行了比较，确定采用纤维素酶、果胶酶按活力比3∶1配方的复合酶处理效果较好；由优化试验得出酶处理的工艺参数为：固液比1∶5，酶用量30 U/g，酶处理时间100 min；在最佳工艺条件下获得高质量的菜籽油与菜籽蛋白，油与蛋白质得率分别为92.6%、82.3%。     

Insecticidal effect and chemical composition of the volatile oil from Bergenia ligulata

The chemical composition of the volatile oil from roots of Bergenia ligulalta was analyzed by GC-MS. A total of 97 compounds were identified. (+)-(6S)-Parasorbic acid (1) (47.45%), isovaleric acid (6.25%), 1,8-cineole (4.24%), (Z)-asarone (3.50%), and terpinen-4-ol (2.96%) were the most prominent constituents. (+)-(6S)-Parasorbic acid (1) was isolated and characterized by spectroscopic data. This is the first report of the existence of (+)-(6S)-parasorbic acid in the saxifrage family. The volatile oil and the isolated compound were tested against Drosophila melanogaster . The results obtained showed that the volatile oil from roots could be considered as natural insecticidal effect agents.     

Chemical composition of the flower oil of Cinnamomum zeylanicum blume

The steam-distilled oil of cinnamon (Cinnamomum zeylanicum) flowers was analyzed by GC and GC-MS. It consists of 23% hydrocarbons and 74% oxygenated compounds. A total of 26 compounds constituting approximately 97% of the oil were characterized. (E)-Cinnamyl acetate (41.98%), trans-alpha-bergamotene (7.97%), and caryophyllene oxide (7.2%) are found to be major compounds. This is the first report on the chemical composition of the flower oil of Cinnamomum zeylanicum.     

Sunflower cake as a natural composite: composition and plastic properties

Nowadays, the end-of-life of plastic products and the decrease of fossil energy are great environmental problems. Moreover, with the increase of food and nonfood transformations of renewable resources, the quantities of agro-industrial byproducts and wastes increase hugely. These facts allow the development of plastic substitutes made from agro-resources. Many researches show the feasibility of molding biopolymers extracted from plants like a common polymeric matrix. Other natural macromolecules are used like fillers into polyolefins, for example. However, limited works present results about the transformation of a natural blend of biopolymers into a plastic material. The aim of this study is the determination of the composition of sunflower cake (SFC) and also the characterization of its components. These were identified by chemical and biochemical analysis often used in agricultural or food chemistry. Most of the extraction and purification processes modify the macrostructure of several biopolymers (e.g., denaturation of proteins, cleavage or creation of weak bonds, etc.). So, the composition of different parts of the sunflower seed (husk, kernel, and also protein isolate) was determined, and the plasticlike properties of their components were studied with thermogravimetric analysis, differential scanning calorimetry, and a dynamic mechanical thermal analysis apparatus. Finally, this indirect way of characterization showed that SFC can be considered a natural composite. In SFC, several components like lignocellulosic fibers [40%/dry matter (DM)], which essentially come from the husk of sunflower seed, can act as fillers. However, other biopolymers like globulins ( approximately 30% of the 30% of sunflower seed proteins/DM of SFC) can be shaped as a thermoplastic-like material because this kind of protein has a temperature of glass transition and a temperature of denaturation that seems to be similar to a melting temperature. These proteins have also viscoelastic properties. Moreover, SFC has similar rheological properties and other physicochemical properties compatible with shaping or molding behaviors of plastic-processing machinery.     

Coriander spice oil: effects of fruit crushing and distillation time on yield and composition

Crushing intensity and distillation time were evaluated for their effects on the oil yield and composition of steam-distilled essential oil from fruits of Coriandrum sativum var. microcarpum L. A comparison of oils produced by laboratory- and pilot-scale stills showed that the two still types gave comparable yields and oil composition. The laboratory still was then used to compare oil yields and compositions from fruits crushed at three different intensities, at intervals during a distillation period of 60 min. Both crushing intensity and distillation time had significant (P< 0.05) effects on the yield and composition of the oil. The maximum oil yield was less from the light-crushed fruits, but the rate of oil recovery was significantly P < 0.05) higher. From the light-crushed fruits, 95% of the maximum yield was extracted in 22.5 min compared with 32 and 39 min for the standard and heavy-crushed fruits, respectively. The effect of crushing intensity on oil composition was most pronounced on the low-boiling-point a-pinene and on the higher-boiling-point geranyl acetate. Crushing had little effect on linalool content, but distillation time could be manipulated to alter the linalool content of the oil.     

水酶法提花生油中乳状液性质及破乳方法

为了破除花生水酶法提油时形成的乳状液,提高出油率,研究了乳状液的性质,比较了界面吸附肽和水相中肽的相对分子质量分布、非变性聚丙烯酰胺凝胶电泳和反相色谱图,发现使乳状液稳定的界面吸附肽性质主要与其构象、组成、电荷等性质有关。通过测定乳状液的静态、动态流变学性质发现,该乳状液是一个典型的以弹性为主的体系,随温度及剪切速率的提高,乳状液的稳定性下降。在上述研究基础上,采用4种物理机械方法破乳,结果显示,冷冻解冻结合离心的方法破乳效果最佳,乳状液中油回收率超过91.6%;而高速剪切是一个再乳化的过程,不能回收乳状液的油。     

Oil and tocopherol content and composition of pumpkin seed oil in 12 cultivars

Twelve pumpkin cultivars (Cucurbita maxima D.), cultivated in Iowa, were studied for their seed oil content, fatty acid composition, and tocopherol content. Oil content ranged from 10.9 to 30.9%. Total unsaturated fatty acid content ranged from 73.1 to 80.5%. The predominant fatty acids present were linoleic, oleic, palmitic, and stearic. Significant differences were observed among the cultivars for stearic, oleic, linoleic, and gadoleic acid content of oil. Low linolenic acid levels were observed (<1%). The tocopherol content of the oils ranged from 27.1 to 75.1 microg/g of oil for alpha-tocopherol, from 74.9 to 492.8 microg/g for gamma-tocopherol, and from 35.3 to 1109.7 microg/g for delta-tocopherol. The study showed potential for pumpkin seed oil from all 12 cultivars to have high oxidative stability that would be suitable for food and industrial applications, as well as high unsaturation and tocopherol content that could potentially improve the nutrition of human diets.     

Equilibrium composition and properties of soil solutions

The high dynamics of their composition are a characteristic feature of soil solutions, which hampers the use of data on the concentrations and activities of elements in the physicochemical studies of soils. The chemical potentials of independent components, whose values depend of the dynamics of the solution composition only slightly, are more stable and efficient parameters. The calculation of the equilibriums by physicochemical simulation and the data on the composition of the water extracts and soil solutions indicated that, in the A1 horizon of a leached chernozem, the chemical potential of the calcium varied from −173.8 to −174.3 kcal/mol and that of magnesium varied from −150.9 to −151.5 kcal/mol when the calcium and magnesium concentrations changed by more than 20 times. In the B1 horizon of the crusted solonetz, the chemical potential of the sodium varied from −81.3 to −82.0 kcal/mol when its concentration changed by 2–3 times. The determination of the chemical potentials of the independent components (K, Na, Ca, Mg, Mn, Fe, Al, and Si) in the relatively simple basis subsystem of the solution and single-component mineral phases with known solubilities allows calculating the standard Gibbs energies of the other soil phases equilibrated with the solution.     

Chemical and colloidal stability of sols in the Al2O3-Fe2O3-SiO2-H2O system: their role in podzolization

Concentrations of dialysable silica in equilibrium with Al₂O₃-SiO₂-H₂O sols at pH 4.5–5.0 confirm the formation of a poorly ordered non-dialysable proto-imogolite species with an Al : Si ratio near 2, close to that of imogolite. Sols with Al : Si>2 give nearly constant levels of free silica in solution in the range 2–6 μg/cm³, indicating equilibrium between proto-imogolite and aluminium hydroxide species. These findings indicate that imogolite-like precipitates in acid soils will buffer silica in solution to within this range during leaching episodes. Imogolite is more stable than a previous estimate suggested, and a revised value for its free energy of formation is proposed: ΔG⁰_f(298.15) = -2929.7 kJ/mol. In Fe₂O₃-SiO₂-H₂O sols, the Fe : Si ratio of the non-dialysable species varies smoothly from 11 to 3 as free silica in solution ranges from 4 to 35 μg/cm³. Such sols are much less colloidally stable than hydroxyaluminium silicate sols, but mixed Al₂O₃—Fe₂O₃—SiO₂—H₂O sols are almost as stable as iron-free sols up to a Fe : Al ratio of 1.5. Thus migration of Al and Fe as mixed hydroxide sols can account for the almost constant ratio of Al to Fe with depth in oxalate extracts from Bs horizons of podzols.