Argan oil-in-water emulsions: Preparation and stabilization

We prepared stable oil-in-water emulsions of argan oil with two different types of mixtures of nonionic emulsifiers. Three different types of oil (Israeli argan oil, Moroccan argan oil, and soybean oil) were emulsified with mixtures of Span 80 and Tween 80. The optimum HLB value for argon oil was 11.0 (±1.0). The argan oil-in-water emulsions were stable for more than 5 mon at 25°C. Synergistic effects were found in enhancing stability of emulsions prepared with sucrose monostearate. The origin of the oil and the internal content of natural emulsifiers, such as monoglycerides and phospholipids, have a profound influence on its interfacial properties and on the stability of the argan oil-in-water emulsions.     

Positional analysis and determination of triacylglycerol structure ofArgania spinosa seed oil

The distribution of fatty acids between the sn-1, sn-2 and sn-3 positions of triacylglycerols fromArgania spinosa seed oil of Morocco has been determined. Saturated fatty acids showed a preference for external positions. The sn-1 position contained slightly more palmitic acid than the sn-3 position, whereas stearic acid was preferentially esterified at the sn-3 position. Linoleic acid occurred predominantly in the sn-2 position with lesser amount evenly distributed between the sn-1 and the sn-3 positions, as generally found in vegetable oils. Oleic acid was distributed with a slight preference shown for the internal position, whereas the distribution between the external positions revealed a slight preference for the sn-1 position. The distribution of the triacylglycerols determined from high-performance liquid chromatography (HPLC) is at variance with that calculated from the 1-random 2-random 3-random distribution theory. This is particularly true for trioleoyl and trilinoleoylglycerols. In contrast, the agreement between theory and experiment is good for triacylglycerols containing two oleoyl and one linoleoyl chains, one oleoyl, one linoleoyl and one palmitoyl chains or one oleoyl, one palmitoyl, and one stearoyl chains.     

Detection of Adulteration in Iranian Olive Oils Using Instrumental (GC,NMR, DSC) Methods

This paper describes an investigation into the usefulness of some instrumental methods (GC, NMR, and DSC) in the detection of adulteration of olive oil with soybean, sunflower, and canola oils (that are relatively cheap oils mixed as adulterants with olive oil). These seed oils were compared with genuine and commercial olive oils, two of which appeared to have been adulterated. It was observed that from among physical and chemical indices, the iodine value and the refractive index in the two olive oil samples (named A and B) were significantly higher (P < 0.01) than in the reference (genuine) olive oil, both values being above standard limits established for olive oil. On the other hand, fatty acid (FA) profiles in these two samples exhibited higher amounts of linolenic and linoleic acids (5.34 and 39.92%, 6.38 and 54.42%, 0.79 and 12.88% for A, B and genuine olive oils respectively) but significantly lower amounts of oleic acid (30.07, 21.72 and 67.86%, respectively). The number and intensity of signals observed using ¹H NMR indicated that the peaks numbered 2 and 7 were useful in the determination of olive oil purity. Because of higher linolenic and linoleic acid contents in samples A and B, the intensity and integrated areas for these two signals were higher than those for other olive oil samples in which signal 2 was not observed and signal 7 had a very low intensity. Satisfactory results were achieved from quantitation of DSC parameters. The results show that due to increased unsaturated FAs in samples A and B and the consequent changes in triacylglycerol profiles, offset crystallization temperature and onset melting temperature in these two olive oils differed from those of the reference and clearly shifted to lower values. Crystallization and melting curves were similar to the corresponding curves observed for soybean and sunflower oils in terms of shape and number of peaks.     

Detection of Extra Virgin Olive Oil Adulteration With Edible Oils Using Front‐Face Fluorescence and Visible Spectroscopies

Synchronous front‐face fluorescence and visible spectroscopies are utilized for the simple, rapid, and nondestructive quantification of extra virgin olive oil (EVOO) adulteration with corn, soybean, and sunflower oils. For each adulterant, 42 adulterated EVOO samples in the adulterant amount in the range 1.0–50 g/100 g were prepared. The partial‐least‐squares regression was executed for quantification. Both full (leave‐one‐out) cross‐validation and external validation were performed to evaluate the predictive ability. The plots of observed vs. predicted values exhibit high linearity. The coefficient of determination (R²) values are larger than 0.99. The root mean square errors of both cross‐validation and prediction are no more than 2%. The detection limits for the three seed oils using fluorescence and visible spectroscopies are in the range of 1.5–2.2% and 1.8–2.4%, respectively. The merit of this method is that both the front‐face fluorescence and visible spectroscopies are recorded toward neat oils, avoiding any sample pretreatment including dilution.     

Adulteration and Presence of Polycyclic Aromatic Hydrocarbons in Extra Virgin Olive Oil Sold on the Brazilian Market

Seventy samples sold in the Brazilian market as extra virgin olive oil (EVOO) were evaluated for the presence of the 13 polycyclic aromatic hydrocarbons (PAH) classified as carcinogenic and genotoxic by the Joint FAO/WHO Expert Committee on Food Additives (JECFA), to verify if the products were adulterated and to evaluate if there is a correlation between PAH presence and adulteration. PAH were detected in 93% of the samples, with summed levels varying from not detected to 41.10 μg/kg. Five samples showed BaP concentration above acceptable levels set by European legislation and by Brazilian regulation (2.0 μg/kg) and 7 presented PAH4 levels above the limit set by European legislation (10.0 µg/kg). The levels of fatty acid composition, sterols content, stigmastadiene and specific extinction did not comply with both Brazilian and International Olive Council (IOC) standards in 18, 31, 30 and 21% of the samples, respectively. The tolerance levels for these analyses in the Brazilian standards are 55.0–83.0 g/100 g (oleic acid), 3.5–21.0 g/100 g (linoleic acid), ≤0.05 g/100 g (trans-oleic acid), ≤0.05 g/100 g (trans-linoleic + trans-linolenic acid), ≤0.15 mg/kg (stigmastadiene), ≤2.50 (K232), ≤0.22 (K270), ≤0.01 (?K), 1000–1600 mg/kg (Σ sterols). Results indicate that 19 samples were adulterated. According to principal component analysis, samples were distinguished as: (1) EVOO with addition of vegetable oil from another source, (2) EVOO with addition of refined oil and (3) samples possibly not adulterated. The variable ΣPAH was related mainly to samples of EVOO with addition of vegetable oil from another source.     

Evaluation of MALDI-TOF/MS Technology in Olive Oil Adulteration

Adulteration of extra virgin olive oil (EVOO) by addition of other vegetable oils or lower-grade olive oils is a common problem of the oil market worldwide. Therefore, we developed a fast protocol for detection of EVOO adulteration by mass spectrometry fingerprinting of triacylglycerol (TAG) profiles based on MALDI-TOF/MS. For that purpose, EVOO TAG profiles were compared with those of edible sunflower oil and olive oil composed of refined olive oil and virgin olive oils. Adulteration of EVOO was simulated by addition of sunflower and mixture of refined olive oil and virgin olive oils at 1, 10 and 20% w/w. Results of mass spectrometry TAG profiling were compared with routinely assessed K values for identification of adulteration. MALDI-TOF/MS technology coupled with statistical analysis was proven as useful for detection of adulteration in EVOO at a rate down to 1%. In contrast, standard spectrophotometric methods failed to identify minor adulterations. In addition, the ability of MALDI-TOF/MS in detection of adulteration was tested on EVOO samples from different geographical regions. Results demonstrated that MALDI-TOF/MS technology coupled with statistical analysis is able to distinguish adulterated oils from other EVOO.     

综合信息指数在芝麻油掺伪检测中的应用

将色谱指纹图谱综合信息指数用于芝麻油的掺伪检验,与加权向量夹角余弦法相比,无需引用"权重",且灵敏度较高,可以快速、准确地检验芝麻油的掺伪量,是一种值得推广的芝麻油掺伪检验新方法。     

Modulation of Olive Oil Quality Using NaCl as Extraction Coadjuvant

The use of four concentrations of common salt (NaCl) used as coadjuvant for the extraction of virgin olive oil has been tested on a laboratory scale and the quality attributes of the oils obtained were compared to those obtained with talc as coadjuvant. The oils extracted from Picual fruits after NaCl addition were not significantly affected in terms of the physicochemical requirements established for extra virgin olive oil, the best level of quality of this produce. Addition of NaCl during the extraction process was positively correlated with the presence of o-diphenol compounds and the stability of the oils obtained. Moreover the use of NaCl resulted in a significant increase in contents of pigments (β-carotene, lutein and chlorophylls a and b) and volatile compounds in the oils.     

Biodegradation ofVernonia galamensis seed Oil byAcinetobacter andPseudomonas sp.

The biodegradability ofVernonia galamensis seed oil (VO) has been demonstrated with two environmental bacterial strains,Acinetobacter Iwoffi (HU 3955), andPseudomonas sp. (HU 4020). A time-dependent increase in the degradative activities of both bacteria species was apparent. There wasca. 60% decrease in the amount of VO over an eightday incubation period. Additionally, lipolytic activity was evident from the amount of free fatty acid (FFA) that was generated. The percent FFA of the residual oil were 82% for thePseudomonas strain, and 62% for theAcinetobacter strain. The weight per epoxy value of the VO in the fermentation medium remained relatively constant over the incubation period, suggesting the lack of preference for either the epoxidized or nonepoxidized acids present in VO.     

Classification of Four Almond Cultivars Using Oil Degradation Parameters Based on FTIR and GC Data

Four almond cultivars (Marcona, Guara, Garrigues and Butte) have been classified using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and gas chromatography (GC) data. The data were obtained by completing the first stages of a thermal oxidative degradation process. The degradation process was monitored by using the variations in the main fatty acid methyl esters (FAME) content determined by GC and to changes in the infrared spectra recorded using the ATR-FTIR technique. In order to classify the almond cultivars, a stepwise linear discriminant analysis was applied to the data. The results indicated that, although the four almond oils evaluated here have a similar fatty acid composition, differences in linoleic acid content may be linked to oxidative stability. Butte cultivar samples had higher linoleic acid content and were more prone to oxidative deterioration.     

Identification of Vegetable Oil or Biodiesel Added to Diesel Using Fluorescence Spectroscopy and Principal Component Analysis

In order to identify possible adulteration of onroad diesel with vegetable oil, fluorescence spectroscopy was used as the analytical technique to differentiate between vegetable oil and biodiesel in diesel blends. Diesel/oil and diesel/biodiesel blends made with different proportions of soy, canola or waste cooking oil were analyzed. The reduced cost of analysis using fluorescence spectroscopy together with the reliability of the results suggest that this technique could be of great use in differentiating between diesel, biodiesel and vegetable oil and could therefore be used for rapid identification or confirmation of adulterated diesel. Furthermore, a compact fluorescence spectrophotometer with an LED excitation source could be used in gas stations or fuel distributors for diesel quality control because of its practicality, low cost and reliability.     

Discrimination of Cod Liver Oil According to Wild/Farmed and Geographical Origins by GC and <Superscript>13</Superscript>C NMR

The objective of this study was to test the possibility of using lipid profiles obtained by gas chromatography (GC) and ¹³C nuclear magnetic resonance (NMR) in authentication of cod liver oils according to wild/farmed and geographical origin. GC and ¹³C-NMR data of cod liver oil from wild and farmed fish from different locations in Norway and Scotland were obtained, and analyzed by principal component analysis (PCA) and linear discriminant analysis (LDA) to test if it was possible to differentiate oil from wild and cultured cod (Gadus morhua L.), and to further elucidate differences between fish from the different farms/catch area. Cod liver oils of wild and farmed origin were clearly separated in the PCA score plot both from GC and NMR data. From NMR data it was also possible to observe groupings based on geographical origin (farm/catch area) of the different samples. Using LDA with cross validation the wild/farmed classification rates were 97% for GC data and 100% for NMR data. In the classification of cod liver oils according to geographical origin (38 samples from six different farms/catch area), the correct classification rate was 63% for GC data and 95% for NMR data.     

Grapefruit Oil Enhances Attraction of Mexican Fruit Flies to a Synthetic Food-Odor Lure

We investigated the attractiveness of grapefruit oil to the Mexican fruit fly. Only high concentrations were attractive in laboratory wind-tunnel bioassays. Attraction of flies to grapefruit oil was not enhanced if they had previous experience with grapefruit. In citrus orchard experiments, undiluted grapefruit oil attracted Mexican fruit flies and enhanced attraction to traps baited with a synthetic food-odor lure emitting ammonia and other nitrogenous chemicals. This is the first demonstration of host fruit odor increasing attraction to another type of attractive blend in Mexican fruit fly. These results indicate differences in the way the flies respond to undiluted grapefruit oil compared with previously tested fruit odors.     

Volatiles released from individual spruce bark beetle entrance holes Quantitative variations during the first week of attack

Volatiles released from individual entrance holes of eight spruce bark beetles (Ips typographus) were collected during the first week of attack on a resistant host tree. In order to quantify the release of the highly volatile 2-methyl-3-buten-2-ol (MB) from attacking males, a new method was developed with deuterated quantification standard released at the time of collection. The amounts of collected volatiles, as analyzed by GC and GC-MS, showed a large variation between individual holes and also between subsequent entrainments from the same hole. Most of the quantified compounds on the average have two maxima, with a pronounced intervening depression. The amounts of releasedcis-verbenol (cV) increased five times during the first two days, while the amounts of MB were consistently high. The attacked spruce tree was not taken by the beetles, and the average amounts of the two aggregation pheromone components, MB and cV, increased again after the first maxima. The first peak of oxygenated monoterpene, released in the beginning of the attack containing -terpineol, terpinen-4-ol, bornyl acetate,trans-pinocarveol, and verbenone, was possibly due to spontaneous oxidation of monoterpene hydrocarbons from the tree. Microorganisms established in the gallery wall phloem probably participated in the production of oxygenated monoterpenes during the second increase.Ips typographus (Coleoptera: Scolytidae).     

Synthesis,Characterization and Performance of Amine Modified Linseed Oil Fatty Amide Coatings

A novel attempt has been made to develop ambient cured polyamine amide (PAA) resins by the condensation polymerization reaction of oil fatty amide diol (N,N-bis 2-hydroxy ethyl linseed oil fatty amide) (HELA) and o-phenylene diamine, which was further modified by poly(styrene-co-maleic anhydride) (SMA) at different phr (parts per hundred part of resin) to get a series of PAA–SMA resins. The structural elucidation of HELA, PAA and PAA–SMA were carried out by FT-IR, ¹H-NMR and ¹³C-NMR spectroscopic techniques. The physico-chemical and physico-mechanical analyses were carried out by standard laboratory methods. Thermal analyses of these resins were accomplished by thermogravimetric analyses (TGA) and differential scanning calorimetry (DSC) techniques. Coatings of PAA–SMA were prepared on mild steel strips to evaluate their physico-mechanical and chemical/corrosion resistance performance under various corrosive environments. It was found that among the PAA–SMA systems, PAA-35 showed the best physico-mechanical and corrosion resistance performance. Thermal studies reveal that the coatings can be safely used up to 305 °C.     

Enzymatic Interesterification of Extra Virgin Olive Oil with a Fully Hydrogenated Fat: Characterization of the Reaction and Its Products

The lipase-catalyzed interesterification of extra virgin olive oil (EVOO) and fully hydrogenated palm oil (FHPO) was studied in a batch reactor operating at 75 °C. The compositions of the semi-solid fat products depend on the reaction conditions and the initial ratio of EVOO to FHPO. The dependence of the quasi-equilibrium product TAG profile on the reaction time was determined for initial weight ratios of EVOO to FHPO from 80:20 to 20:80. Lipozyme TL IM, Lipozyme RM IM and Novozym 435 were employed as biocatalysts. The interesterification reaction was optimized with respect to the type and loading of biocatalyst. Equilibrium was approached in the shortest time with Novozym 435 (80% conversion in 4 h). The chemical, physical, and functional properties of the products were characterized. Appropriate choices of the reaction conditions and the initial ratio of EVOO to FHPO lead to TAG with melting profiles and solid fat contents similar to those of commercial products. Differences were observed in the solid fat contents, melting profiles, and oxidative stabilities of the various interesterified products and also between the indicated properties of each category of product and the corresponding physical blend of the precursor reagents.     

Review on Recent Trends in Rice Bran Oil Processing

Rice bran oil (RBO) is popular in several countries such as Japan, India, Korea, China and Indonesia as a cooking oil. It has been shown that RBO is an excellent cooking and salad oil due to its high smoke point and delicate flavor. The nutritional qualities and health effects of rice bran oil are also established. RBO is rich in unsaponifiable fraction (unsap), which contains the micronutrients like vitamin E complexes, gamma oryzanol, phytosterols, polyphenols and squalene. However, the high FFA and acetone-insoluble content of RBO made it difficult for processing. Therefore, in recent years, research interest has been growing in RBO processing to obtain good quality oil with low refining loss. This review article deals with detailed reports on RBO processing including membrane-based techniques from the production and quality point of view.     

Essential Oil Yield and Composition Reflect Browsing Damage of Junipers

The impact of browsing on vegetation depends on the relative density and species composition of browsers. Herbivore density and plant damage can be either site-specific or change seasonally and spatially. For juniper (Juniperus communis) forests of a sand dune region in Hungary, it has been assumed that plant damage investigated at different temporal and spatial scales would reflect selective herbivory. The level of juniper damage was tested for a possible correlation with the concentration of plant secondary metabolites (PSMs) in plants and seasonal changes in browsing pressure. Heavily browsed and nonbrowsed junipers were also assumed to differ in their chemical composition, and the spatial distribution of browsing damage within each forest was analyzed to reveal the main browser. Long-term differences in local browsing pressure were also expected and would be reflected in site-specific age distributions of distant juniper populations. The concentrations of PSMs (essential oils) varied significantly among junipers and seasons. Heavily browsed shrubs contained the lowest oil yield; essential oils were highest in shrubs bearing no damage, indicating that PSMs might contribute to reduce browsing in undamaged shrubs. There was a seasonal fluctuation in the yield of essential oil that was lower in the summer period than in other seasons. Gas chromatography (GC) revealed differences in some essential oil components, suggesting that certain chemicals could have contributed to reduced consumption. The consequential long-term changes were reflected in differences in age distribution between distant juniper forests. These results confirm that both the concentration of PSMs and specific compounds of the essential oil may play a role in selective browsing damage by local herbivores.     

Allelopathic Potential and Chemical Constituents of Volatile Oil from Ageratum conyzoides

Fresh leaves and volatile oil of the important weed Ageratum conyzoides in south China were highly inhibitory to seedling growth of various cultivated crops, especially in an adverse habitat. The constituents of the volatile oil were analyzed by GC-MS. Eleven components were identified and six main components, precocene I, precocene II, 3,3-dimethyl-5-tert-butylindone, -caryophyllene, -bisabolene, and fenchyl acetate, were isolated by means of column chromatography. Precocene I, precocene II, -caryophyllene, and 3,3-dimethyl-5-tert-butylindone inhibited seedling growth of acceptor plants. Inhibitory activity of the volatile oil was more intense than that of the pure components. Fenchyl acetate and -bisabolene have no inhibitory activity, but when mixed with precocene II, they increased the inhibitory activity to growth of acceptor seedling plants. Experiments show that allelopathic synergism exists among allelochemicals of Ageratum conyzoides.