Piper nigrum Oil - Determination of Selected Terpenes for Quality Evaluation

The growing demand and commercial value of black pepper (Piper nigrum) has resulted in considerable interest in developing suitable and cost-effective methods for chemical characterization and quality evaluation purposes. In the current study, an extensive set of oil samples (n = 23) that were extracted by steam distillation from black pepper seeds was investigated to compare the chemical profiles of samples originating from nine major producing countries, as well as to identify potential chemical markers for quality evaluation. The twenty-two most abundant volatile compounds, mainly terpenes, in these oils were determined by conventional GC/MS analysis. Principal component analysis with this set of data revealed distinct clusters for samples that originated from China and Malaysia. Relatively low concentrations of sabinene (< 0.2%) and high concentrations of 3-carene (10.9 - 21.1%) were observed in these samples, respectively, compared to oil samples from other countries. The enantiomeric distributions of key terpene markers, viz., β-pinene, sabinene, limonene, and terpinen-4-ol, were determined by chiral GC/MS analysis. Interestingly, for these four monoterpenes, levo-isomers were found to be predominant, emphasizing the highly conserved enzymatic processes occurring in P. nigrum. Moreover, consistent enantiomeric ratios ((-) isomer/(+) isomer) of 92.2 ± 3.0% for β-pinene, 94.8 ± 2.8% for sabinene, 60.7 ± 1.1% for limonene, and 78.3 ± 1.3% for terpinen-4-ol were observed, independent of geographical location. These results demonstrate the potential of using stereospecific compositions as chiral signatures for establishing the authenticity and quality of black pepper oil.

Is Low-field NMR a Complementary Tool to GC-MS in Quality Control of Essential Oils? A Case Study: Patchouli Essential Oil

High-field NMR is an expensive and important quality control technique. In recent years, cheaper and simpler low-field NMR has become available as a new quality control technique. In this study, 60 MHz ¹H-NMR was compared with GC-MS and refractometry for the detection of adulteration of essential oils, taking patchouli essential oil as a test case. Patchouli essential oil is frequently adulterated, even today. In total, 75 genuine patchouli essential oils, 10 commercial patchouli essential oils, 10 other essential oils, 17 adulterants, and 1 patchouli essential oil, spiked at 20% with those adulterants, were measured. Visual inspection of the NMR spectra allowed for easy detection of 14 adulterants, while gurjun and copaiba balsams proved difficult and one adulterant could not be detected. NMR spectra of 10 random essential oils differed not only strongly from patchouli essential oil but also from one another, suggesting that fingerprinting by low-field NMR is not limited to patchouli essential oil. Automated chemometric evaluation of NMR spectra was possible by similarity analysis (Mahalanobis distance) based on the integration from 0.1 - 8.1 ppm in 0.01 ppm increments. Good quality patchouli essential oils were recognised as well as 15 of 17 deliberate adulterations. Visual qualitative inspection by GC-MS allowed for the detection of all volatile adulterants. Nonvolatile adulterants, and all but one volatile adulterant, could be detected by semiquantitation. Different chemometric approaches showed satisfactory results. Similarity analyses were difficult with nonvolatile adulterants. Refractive index measurements could detect only 8 of 17 adulterants. Due to advantages such as simplicity, rapidity, reproducibility, and ability to detect nonvolatile adulterants, 60 MHz ¹H-NMR is complimentary to GC-MS for quality control of essential oils.

Metal absorption properties of Mentha spicata grown under tannery sludge amended soil-its effect on antioxidant system and oil quality

Tannery sludge (TS) is hazardous to environment and its disposal in an ecofriendly manner is a major challenge. An experiment was conducted to investigate the metal absorption properties of Mentha spicata grown under different levels of TS amended soil (soil: sludge in 100:0, 75:25, 50:50, 25:75 and 0:100 ratio) and its effect on the antioxidant system and oil quality. At 75:25 ratio of sludge and soil, metal translocation factor was ≥0.5 for Cr, Cd, and Co and for Ni and for Pb ≥ 1. Carvone, limonene, dihydrocarvone and other oil constituents along with biomass were maximum in 75:25 ratio of sludge and soil. Superoxide dismutase (SOD), CAT (Catalases), POD (Peroxidases), MDA (Malondialdehyde) and proline play a major role in detoxification of reactive oxygen species generated due to TS (heavy metal stress). Antioxidant (SOD, CAT and POD), MDA and proline showed an increasing trend as the concentration of TS increased with the treatments. To test the relationship between 23 character principal component analysis (PCA) was performed. PC-I contributed 56% of total variance while PC-II contributed 37% of total variance. The results concluded that M. spicata performed well in terms of oil yield and multiple metal translocations in 75:25 sludge and soil ratio.

Molecular breeding for introgression of fatty acid desaturase mutant alleles (ahFAD2A and ahFAD2B) enhances oil quality in high and low oil containing peanut genotypes

High oleate peanuts have two marketable benefits, health benefits to consumers and extended shelf life of peanut products. Two mutant alleles present on linkage group a09 (ahFAD2A) and b09 (ahFAD2B) control composition of three major fatty acids, oleic, linoleic and palmitic acids which together determine peanut oil quality. In conventional breeding, selection for fatty acid composition is delayed to advanced generations. However by using DNA markers, breeders can reject large number of plants in early generations and therefore can optimize time and resources. Here, two approaches of molecular breeding namely marker-assisted backcrossing (MABC) and marker-assisted selection (MAS) were employed to transfer two FAD2 mutant alleles from SunOleic 95R into the genetic background of ICGV 06110, ICGV 06142 and ICGV 06420. In summary, 82 MABC and 387 MAS derived introgression lines (ILs) were developed using DNA markers with elevated oleic acid varying from 62 to 83%. Oleic acid increased by 0.5-1.1 folds, with concomitant reduction of linoleic acid by 0.4-1.0 folds and palmitic acid by 0.1-0.6 folds among ILs compared to recurrent parents. Finally, high oleate ILs, 27 with high oil (53-58%), and 28 ILs with low oil content (42-50%) were selected that may be released for cultivation upon further evaluation.

Quantitative analysis and health risk assessment of polycyclic aromatic hydrocarbons in edible vegetable oils marketed in Shandong of China

This work studies on the quantitative analysis and health risk assessment of polycyclic aromatic hydrocarbons (PAHs) in edible vegetable oils in Shandong, China. The concentrations of 15 PAHs in 242 samples were determined by high performance liquid chromatography coupled with fluorescence detection. The results indicated that the mean concentration of 15 PAHs in oil samples was 54.37 μg kg(-1). Low molecular weight PAH compounds were the predominant contamination. Especially, the carcinogenic benzo(a)pyrene (BaP) was detected at a mean concentration of 1.28 μg kg(-1), which was lower than the limit of European Union and China. A preliminary evaluation of human health risk assessment for PAHs was accomplished using BaP toxic equivalency factors and the incremental lifetime cancer risk (ILCR). The ILCR values for children, adolescents, adults, and seniors were all larger than 1 × 10(-6), indicating a high potential carcinogenic risk on the dietary exposed populations.

Sensory analysis and consumer acceptance of 140 high-quality extra virgin olive oils

BACKGROUND

Sensory analysis is a crucial tool for evaluating the quality of extra virgin olive oils. One aim of such an investigation is to verify if the sensory attributes themselves - which are strictly related to volatile and phenolic compounds - may permit the discrimination of high-quality products obtained by olives of different cultivars and/or grown in various regions. Moreover, a crucial topic is to investigate the interdependency between relevant parameters determining consumer acceptance and objective sensory characteristics evaluated by the panel test.

RESULTS

By statistically analysing the sensory results, a grouping - but not discriminatory - effect was shown for some cultivars and some producing areas. The preference map shows that the most appreciated samples by consumers were situated in the direction of the 'ripe fruity' and 'sweet' axis and opposite to the 'bitter' and 'other attributes' (pungent, green fruity, freshly cut grass, green tomato, harmony, persistency) axis.

CONCLUSION

Extra virgin olive oils produced from olives of the same cultivars and grown in the same areas shared similar sensorial attributes. Some differences in terms of expectation and interpretation of sensory characteristics of extra virgin olive oils might be present for consumers and panellists: most of the consumers appear unfamiliar with positive sensorial attributes, such as bitterness and pungency.

Thermal and chemical evaluation of naturally auto-oxidised virgin olive oils: a correlation study

BACKGROUND

The nature of the relationship between differential scanning calorimetry thermal properties and the oxidation and hydrolysis compounds formed during a real auto-oxidation process in virgin olive oils has not been evaluated so far, as these samples are difficult to find. In this work, 21 samples of virgin olive oil, stored under ideal conditions since their years of production (production range 1991-2005) to develop the natural auto-oxidation process, were analysed in order to evaluate this relationship.

RESULTS

Oils stored the longest time showed the highest hydrolytic degradation while the others exhibited higher contents of oxidised fatty acids and triacylglycerols, instead. Thermal properties of transitions were differently influenced by degradation compounds with the onset of both the cooling and heating profiles particularly influenced by diacylglycerols and oxidised lipids. Chemical data and thermal properties were correlated by using principal component analysis. Twenty-three variables were selected for the analysis with the first component fully segregating samples into two groups according to the year of storage and the level of hydrolysis and/or oxidation, on the basis of selected thermal properties obtained by cooling and heating transitions.

CONCLUSIONS

These preliminary findings showed that differential scanning calorimetry could be considered an useful tool to evaluate lipid degradation in virgin olive oils, indicating its value as a support to chemical techniques.

Characterization and evaluation of olive germplasm in southern Italy

BACKGROUND

The southern Italian region of Campania has suitable pedo-climatic conditions and a large varietal heritage able to produce oils with high typicality. The aim of this study was to characterize 20 cultivars belonging to Campania's olive germplasm, evaluating their vegetative and production aspects and their oil quality characteristics. The study was conducted from 2003 to 2009, observing the following aspects in six plants per variety: entry into production, vigour, ripening and drupe oil content. The following analyses were carried out on monovarietal oils, obtained by microextractor: acid composition, polyphenol content and aromatic profile.

RESULTS

The agronomic results showed early entry into production for the cultivars Racioppella, Ortolana, Biancolilla and Carpellese. However, entry into production was delayed for Ritonnella, Ortice, Cornia and Rotondella. As regards vegetative behaviour, Asprinia, from the province of Caserta and Pisciottana and Carpellese, from the province of Salerno, proved the most vigorous cultivars.

CONCLUSION

Groups of similar cultivars emerged from chemical and sensory analysis of their oils, while other accessions were well characterized and separated from each other, showing a high level of diversity and specificity.

Varietal tracing of virgin olive oils based on plastid DNA variation profiling

Olive oil traceability remains a challenge nowadays. DNA analysis is the preferred approach to an effective varietal identification, without any environmental influence. Specifically, olive organelle genomics is the most promising approach for setting up a suitable set of markers as they would not interfere with the pollinator variety DNA traces. Unfortunately, plastid DNA (cpDNA) variation of the cultivated olive has been reported to be low. This feature could be a limitation for the use of cpDNA polymorphisms in forensic analyses or oil traceability, but rare cpDNA haplotypes may be useful as they can help to efficiently discriminate some varieties. Recently, the sequencing of olive plastid genomes has allowed the generation of novel markers. In this study, the performance of cpDNA markers on olive oil matrices, and their applicability on commercial Protected Designation of Origin (PDO) oils were assessed. By using a combination of nine plastid loci (including multi-state microsatellites and short indels), it is possible to fingerprint six haplotypes (in 17 Spanish olive varieties), which can discriminate high-value commercialized cultivars with PDO. In particular, a rare haplotype was detected in genotypes used to produce a regional high-value commercial oil. We conclude that plastid haplotypes can help oil traceability in commercial PDO oils and set up an experimental methodology suitable for organelle polymorphism detection in the complex olive oil matrices.

Effect of nutrient-based fertilisers of olive trees on olive oil quality

BACKGROUND

This work was conducted to determine the effects of two nutrient-based fertilisers on the general physicochemical characteristics (including free fatty acid content, peroxide value and UV spectrophotometric characteristics), fatty acid profile, total phenols, o-diphenols and phytosterol composition of olive oil. Foliar applications were carried out in two successive years and included four treatments: TC (control, without foliar nutrition), T1 (rich in nitrogen, applied at the start of vegetation, 10 days later and 20 days later), T2 (rich in boron, magnesium, sulfur and manganese, applied at the beginning of flowering and 10 days later) and T3 (T1+T2). At the end of the experiment (after 2 years), oils were extracted and analysed.

RESULTS

No effect was found on either general physicochemical characteristics or fatty acid composition. Foliar fertilisation caused a significant decrease in both polyphenol and o-diphenol contents. Total sterol content was unaffected by foliar fertilisation. However, the phytosterol composition of the oil, particularly its β-sitosterol level, was markedly improved after foliar nutrient application. Principal component analysis of the phytosterol composition showed discrimination between the control oil and the oils from T1, T2 and T3 treatments.

CONCLUSION

The results of this study extend the current knowledge of such cross-talk between plant nutrition and quality of oil.

Effect of growing location, malaxation duration and citric acid treatment on the quality of olive oil

BACKGROUND

The total phenolic compounds of olive oil exert antiradical activity at cellular level and can prevent cardiovascular disease, metabolic syndrome and cancer. Increased awareness of its health benefits has increased the consumption of olive oil around the world. An alternative processing technique effective in increasing the amount of oil extracted while maintaining the oil quality is needed to meet the rising global demand for olive oil.

RESULTS

Addition of 0.3 g mL(-1) citric acid at 1:1000 (v/w) to olive paste followed by a 30 min malaxation period significantly increased the oil recovery, concentration of total phenolic compounds and antiradical activity by 46.23, 120.27 and 31.48% respectively. While there was no significant effect on the acidity, the peroxide value was significantly reduced by 63.85%. The organoleptic characteristics of the olive oil extracted with citric acid were also comparable to those of the control.

CONCLUSION

Addition of 0.3 g mL(-1) citric acid (i.e. 30% w/v) at 1:1000 (v/w) to olive paste followed by a 30 min malaxation period in a Blixer(®) 4.0 blender is the most promising extraction technique to improve the oil recovery, concentration of total phenolic compounds and antiradical activity of the extracted olive oil without compromising other quality parameters.

Simultaneous determination of 15 multiresidue organophosphorous pesticides in camellia oil by MSPD-GC-MS

A one step method based on matrix solid-phase dispersion for simultaneous determination of 15 organophosphorous pesticide residues in camellia oil was developed. The sample preparation could finish in 5 min without extraction procedure, and then analyzed by gas chromatograph-mass spectrometer. Average recoveries ranged between 73.2 % and 108.6 %, with relative standard deviation values (intra-day and inter-day) lower than 16 % at two concentration levels. The method limit of detection was 5 ng/g, which could meet the regulatory maximum residue limits for the pesticides.

GC-MS analysis of essential oils from Salvia officinalis L.: comparison of extraction methods of the volatile components

In this paper, comparison of the volatile components composition in the samples obtained by hydrodistillation and solid-phase microextraction of Salvia officinalis was described. Different sample preparation techniques showed considerable differences in volatiles composition, especially with respect to sesqui- and diterpenoids. The comparison of the sage essential oil obtained by hydrodistillation in the Deryng and Clevenger type apparatus, according to the pharmacopoeial methods (FP VI and VII), showed the presence of the same terpenoids in both essential oils, however, the relative percentage composition of the components were different. These differences are caused by the different extraction times used in both methods. Since each essential oil to be admitted to medicinal use should meet requirements regarding the composition of major chemical components, the minimum time for the hydrodistillation of the essential oils from sage should be 1 h.

Quality parameters for cold pressed edible argan oils

Argan oil belongs to the high-price vegetable oils on the market. Therefore, consumers have the right to purchase a high-quality product. The quality of edible vegetable oils is defined in food standards in which sensory quality is the most important feature. Additional parameters are defined to assess the identity of oils or to evaluate their oxidative state. The sensory quality of cold pressed argan oil is altered if the production has not been performed with reasonable care regarding raw material and extraction. Only oil from roasted seeds extracted by a screw-press had a sufficient sensory quality over a period of 20 weeks without unacceptable sensory attributes. Under accelerated storage conditions oil from roasted seeds extracted by a screw-press remained below the limits given by the Codex Alimentarius or the German guideline for Edible Fats and Oils for peroxide and totox value. Oil from unroasted seeds or oil from goat-digested roasted seeds and extracted by a screw-press, as well as oil from roasted seeds traditionally extracted, exceeded these limits. Initial oxidative stability of oil from unroasted seeds was significantly lower than that of the other oils. After 35 days under accelerated storage, oil from roasted seeds obtained using a screw-press showed the highest oxidative stability. Moreover, tocopherol and phytosterol compositions are useful features of argan oil.

Evaluation of the quality of postharvest rapeseed by means of an electronic nose

BACKGROUND

Rapeseed is a valuable source of edible oil. The presence of even a small amount of mouldy or burnt rapeseed in a particular production batch deteriorates the quality of the edible oil obtained from it. Since the traditional method of using a panel of experts is time-consuming, there is a need for fast and easy methods for rapeseed quality evaluation by intelligent devices to replace human labour.

RESULTS

For rapeseed quality evaluation, an electronic nose equipped with an array of eight quartz microbalance sensors and four metal oxide semiconductor sensors was used. Signals generated by the sensors were analysed by principal component analysis and discriminant function analysis. Identification of samples that contained small proportions of mouldy or burnt rapeseed was possible despite the differences between the particular varieties studied.

CONCLUSION

Electronic nose technology has shown the possibility of detecting samples of faulty rapeseed at very low contamination levels and distinguishing them with high probability from sound rapeseed.

Preparation and certification of standard reference material 3278 tocopherols in edible oils

Standard Reference Material (SRM) 3278 Tocopherols in Edible Oils has been issued for use as a quality assurance tool in the measurement of tocopherols. Like other natural-matrix SRMs, this material can be used in method validation or in assignment of tocopherol values to in-house quality control materials. Because most edible oils contain one predominant tocopherol isoform, the SRM is a blend of sunflower, soy, canola, and safflower oils to provide roughly comparable chromatographic peak heights of the two main tocopherols, γ and α, with smaller amounts of δ and β. The four tocopherol isoforms were determined by three independent liquid chromatography methods with absorbance and fluorescence detection. Various chromatographic and detection modes are used for assignment of certified values because biases inherent to one method should not be present in the other, and the existence of bias can therefore be identified.

Quality and statistical classification of Brazilian vegetable oils using mid-infrared and Raman spectroscopy

Palm oil, soy oil, sunflower oil, corn oil, castor oil, and rapeseed oil were analyzed with Fourier transform infrared (FT-IR) and FT-Raman spectroscopy. The quality of different oils was evaluated and statistically classified by principal component analysis (PCA) and a partial least squares (PLS) regression model. First, a calibration set of spectra was selected from one sampling batch. The qualitative variations in spectra are discussed with a prediction of oil composition (saturated, mono- and polyunsaturated fatty acids) from mid-infrared analysis and iodine value from FT-Raman analysis, based on ratioing the intensity of bands at given wavenumbers. A more robust and convincing oil classification is obtained from two-parameter statistical models. The statistical analysis of FT-Raman spectra favorably distinguishes according to the iodine value, while the mid-infrared spectra are most sensitive to hydroxyl moieties. Second, the models are validated with a set of spectra from another sampling batch, including the same oil types as-received and after different aging times together with a hydrogenated castor oil and high-oleic sunflower oil. There is very good agreement between the model predictions and the Raman measurements, but the statistical significance is lower for mid-infrared spectra. In the future, this calibration model will be used to check vegetable oil qualities before using them in polymerization processes.

Quality evaluation of olive oil by statistical analysis of multicomponent stable isotope dilution assay data of aroma active compounds

An instrumental method for the evaluation of olive oil quality was developed. Twenty-one relevant aroma active compounds were quantified in 95 olive oil samples of different quality by headspace solid phase microextraction (HS-SPME) and dynamic headspace coupled to GC-MS. On the basis of these stable isotope dilution assay results, statistical evaluation by partial least-squares discriminant analysis (PLS-DA) was performed. Important variables were the odor activity values of ethyl isobutanoate, ethyl 2-methylbutanoate, 3-methylbutanol, butyric acid, E,E-2,4-decadienal, hexanoic acid, guaiacol, 2-phenylethanol, and the sum of the odor activity values of Z-3-hexenal, E-2-hexenal, Z-3-hexenyl acetate, and Z-3-hexenol. Classification performed with these variables predicted 88% of the olive oils' quality correctly. Additionally, the aroma compounds, which are characteristic for some off-flavors, were dissolved in refined plant oil. Sensory evaluation of these models demonstrated that the off-flavors rancid, fusty, and vinegary could be successfully simulated by a limited number of odorants.

[Oxidative and hydrolytic deterioration of palm oil and fat products based on it under various conditions of storage and transportation]

Studies have been conducted on the effect of storage conditions for refined deodorized palm oil on the quality and safety: in containers made of ferrous metals (mild steel) at unregulated temperature, in sealed plastic bags at the temperature -20 degrees C in stainless steel under stratification of nitrogen at the temperature of 40+/-1 degrees C. The choice of the objects of study determined by the normative documents of the Russian Federation governing the transportation and storage of vegetable oils and fat products based on them. All samples of palm oil with peroxide value of 1,0 to 1,5 meq O2/kg indicated the presence of a weak foreign taste, is not peculiar impersonalfat, the samples with peroxide value above 1,5 meq O2/kg were observed pronounced off-flavors and odors characteristic of stale oil. Rancidity was observed in samples having peroxide value of 2,0 meq O2/kg or more. Free acid value and anizidin value for the studied period changed to a lesser extent, from 0,06 to 0,1 mg KOH/g and from 1,2 to 1,4 respectively. It is proved that, transportation/storage of palm oil at the temperature above 50 degrees C without stratification of nitrogen greatly accelerates the process of oxidative damage. Based on these data we can recommend transportation/storage and management process with the least possible time of contact of melted palm oil with oxygen to produce high-quality final product (within 2-3 hours from the time of melting).

Effect of salt, drought and metal stress on essential oil yield and quality in plants

Essential oil extracted from plants is of high commercial value in medicine, cosmetics and perfumery. Enhancing yield and maintaining the quality of oil is of significant commercial importance. Production of oil in plants is dependent on various biotic and abiotic factors to which the plants are subjected during their growth. Plants are exposed to various degrees of stress on account of natural and human-induced factors. Salinization, drought and presence of heavy metals in the substratum cause substantial effect on the yield and quality of bioactive constituents in the oil. In many plants, the level and kind of stress have detrimental effects on the growth and development. This review provides an account of the studies on some common abiotic stresses to which essential oil plants are exposed during their growth period and their influence on quality and quantity of oil. The yield and quality vary in different plants and so is the response. Enhancing essential oil productivity is an important challenge, and understanding the role played by stress may offer significant advantages to the essential oil farmers and processing industry. Scientific evaluation of the data on many important but unexplored essential oil plants will also help in mitigating, ameliorating and minimizing the harmful effects caused by stress.

Research in olive oil: challenges for the near future

Olive oil, a traditional food product with thousands of years of history, is continually evolving toward a more competitive global market. Being one of the most studied foods across different disciplines, olive oil still needs intensive research activity to face some vulnerabilities and challenges. This perspective describes some of them and shows a vision of research on olive oil for the near future, bringing together those aspects that are more relevant for better understanding and protection of this edible oil. To accomplish the most urgent challenges, some possible strategies are outlined, taking advantage of the latest analytical advances, considering six areas: (i) olive growing; (ii) processing, byproduct, and environmental issues; (iii) virgin olive oil sensory quality; (iv) purity, authentication, and traceability; (v) health and nutrition; (vi) consumers. The coming research, besides achieving those challenges, would increase the understanding of some aspects that are still the subject of debate and controversy among scientists focused on olive oil.

[Fatty acid composition variability of rapeseed oil: classical selection and biotechnology]

The problems and achievements in the rapeseed Brassica napus L. var. oleifera breeding directed on the change of fatty acid composition in seed oil with the use of traditional and genetic engineering approaches are analyzed. It is noticed that the combination of biotechnological workings out and methods of classical breeding is the optimum for the further improvement of rapeseed oil composition.

Detection of hazelnut oil in extra-virgin olive oil by analysis of polar components by micro-solid phase extraction based on hydrophilic liquid chromatography and MALDI-ToF mass spectrometry

The oil polar fraction may have a great potential for the characterization of vegetable oils and for the individuation of adulterations. In particular, adulteration of extra-virgin olive oil (EVOO) with hazelnut oil (HO) is one of the most difficult ones to detect due to the similar composition as regards triacylglycerol, total sterol and fatty acid profile. A new micro-solid phase extraction (µ-SPE) procedure based on hydrophilic liquid chromatography (HILIC) micro-columns was developed for the selective extraction and enrichment of polar compounds from EVOO and HO before matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-ToF-MS) analysis. The method permits a simple and fast qualitative analysis of the polar fraction of the oils under study; furthermore, some peaks (such as the m/z ions 496.39, 520.46 and 522.47) were found to be present only in HO, indicating that they could be diagnostic for the presence of HO in EVOO. In order to verify the potential of the method for the individuation of this adulteration, EVOO was progressively adulterated with variable quantities of HO, subjected to the HILIC enrichment and finally to MALDI-ToF-MS analysis; the detection of adulteration was possible up to the level of 5%. Eventually, diagnostic polar compounds were identified as lysophosphatidylcholine (LPC) (16:0/0:0), LPC (18:2/0:0), LPC (18:1/0:0) by means of capillary liquid chromatography-electrospray ionization-quadrupole-ToF-MS (CapLC-ESI-Q-ToF-MS) analysis.

Determination of trigonelline in seeds and vegetable oils by capillary electrophoresis as a novel marker for the detection of adulterations in olive oils

A capillary electrophoresis method with UV detection was developed for the first time for the determination of the pyridine betaine trigonelline (N-methylnicotinic acid) in seeds and vegetable oils. Analytical characteristics of the method showed its good performance in terms of linearity (r > 0.999), precision (relative standard deviations < 5%), and limits of detection (up to 0.9 microM or 1 ng/g for oils). The developed method was applied to the analysis of soy and sunflower seeds, three varieties of olives, and sunflower, soy, and extra virgin olive oils. Trigonelline was determined in soy and sunflower seeds and their respective oils, whereas it was not detected in olives or olive oils. Different mixtures of extra virgin olive oil with seed oils were analyzed, detecting up to 10% of soy oil in olive oil. As a consequence, trigonelline is proposed in this work as a novel marker for the detection of adulterations of olive oils with other vegetable oils such as soy and sunflower oils.

Stereospecific analysis of triacylglycerols as a useful means to evaluate genuineness of pumpkin seed oils: lesson from virgin olive oil analyses

In Slovenia two superb vegetable oils with high added nutritional value are produced: "Ekstra devisko oljcno olje Slovenske Istre (extra virgin olive oil from Slovene Istra)" and "Stajersko prekmursko bucno olje (pumpkin seed oil from Slovenia)". Their quality and genuineness must be monitored as adulteration can easily be undertaken. Olive oil genuineness determination experiences can show how analyses following an experience data-driven decision tree gathering several chemical determinations (fatty acids, (E)-isomers of fatty acids, sterol and tocopherol determinations) may be helpful in assessing the pumpkin seed oil from Slovenia genuineness. In the present work a set of HPLC triacylglycerol determinations was performed, based on the nine main triacylglycerols (LLLn, LLL, PLL, LOO, PLO, OOO, POO, SPL, and SLS) on a limited number of different pumpkin seed oils from northeastern Slovenia. The performed determinations showed that stereospecific analyses of triacylglycerols together with other chemical determinations can be useful in building a protocol for the evaluation of the genuineness of pumpkin seed oil from Slovenia.

Virgin olive oil authentication by multivariate analyses of 1H NMR fingerprints and delta13C and delta2H data

(1)H NMR fingerprints of virgin olive oils (VOOs) from the Mediterranean basin (three harvests) were analyzed by principal component analysis, linear discriminant analysis (LDA), and partial least-squares discriminant analysis (PLS-DA) to determine their geographical origin at the national, regional, or PDO level. Further delta(13)C and delta(2)H measurements were performed by isotope ratio mass spectrometry (IRMS). LDA and PLS-DA achieved consistent results for the characterization of PDO Riviera Ligure VOOs. PLS-DA afforded the best model: for the Liguria class, 92% of the oils were correctly classified in the modeling step, and 88% of the oils were properly predicted in the external validation; for the non-Liguria class, 90 and 86% of hits were obtained, respectively. A stable and robust PLS-DA model was obtained to authenticate VOOs from Sicily: the recognition abilities were 98% for Sicilian oils and 89% for non-Sicilian ones, and the prediction abilities were 93 and 86%, respectively. More than 85% of the oils of both categories were properly predicted in the external validation. Greek and non-Greek VOOs were properly classified by PLS-DA: >90% of the samples were correctly predicted in the cross-validation and external validation. Stable isotopes provided complementary geographical information to the (1)H NMR fingerprints of the VOOs.

Lipid compositions and French registered designations of origins of virgin olive oils predicted by chemometric analysis of mid-infrared spectra

The combination of mid-infrared (MIR) spectroscopy with multivariate analysis provides an original approach to study the profile of virgin olive oils (VOOs) in relation to composition and geographical origin. Chemometric treatment of mid-infrared spectra (n=402) is assessed for quantification of fatty acids (14 components) and triacylglycerols (19 components) in VOO samples and for classification into six very geographically closed registered designations of origin (RDOs) of French VOO ("Aix-en-Provence", "Haute-Provence", "Vallée des Baux de Provence", "Nice", "Nîmes", and "Nyons"). Spectroscopic interpretation of regression vectors has shown that each RDO is correlated to one specific component of VOO according to their cultivar compositions. The results are satisfactory, in spite of the similarity of cultivar compositions between two denominations of origin ("Aix-en-Provence" and "Vallée des Baux de Provence"). Chemometric treatment of MIR spectra makes it possible to obtain similar results to those obtained by time-consuming analytical techniques such as gas chromatography (GC) and high-performance liquid chromatography (HPLC) and constitutes a fast and robust tool for authentication of these French VOOs.

An ecofriendly approach to process rice bran for high quality rice bran oil using supercritical carbon dioxide for nutraceutical applications

An integrated approach to extraction and refining of RBO using supercritical carbon dioxide (SC-CO2) in order to preserve the nutritionally important phytochemicals is reported here. Process variables such as pressure, temperature, time, solvent flow rate and packing material on extraction yield and quality of RBO were investigated using a pilot model SC-CO2 extraction system. Three isobaric (350, 425 and 500 bar), three isothermal temperatures (50, 60 and 70 degrees C), three extraction times (0.5, 1 and 1.5h), at 40/min CO2 flow rate and three packing materials (pebbles, glass beads and structured SS rings) were employed. The RBO yield with SC-CO2 extraction increased with temperature and time under isobaric conditions. At the 60 degrees C isotherm, an increase in the RBO yield was obtained with an increase in the pressure and time. The RBO yield increased significantly with structured SS rings used as packing material. The RBO extracted with SC-CO2 had negligible phosphatides, wax and prooxidant metals (Fe and Cu) and was far superior in color quality when compared with RBO extracted with hexane. At the optimum condition of extraction at 500 bar, 60 degrees C for 1.5h, with structured SS rings used as packing material, the yield of RBO was comparable with that of hexane extraction (22.5%). The phytochemical contents of the RBO under the optimum conditions were in the range of tocols, 1500-1800 ppm; sterols, 15,350-19,120 ppm and oryzanol 5800-11,110 ppm.

Standardization and stability studies of neuroprotective lipid soluble fraction obtained from Curcuma longa

The lipid soluble fraction of curcuma longa, i.e. herbal medicament (HM) was isolated from rhizome of curcuma longa by solvent extraction method. The identification of chemical constituent present in HM was done with GC, GC-MS. The standardization of HM was done using HPLC method on the basis of three-marker compound isolated, i.e. ar-turmerone, turmerone and curlone. The effect of temperature, pH and light on stability of marker compounds of HM was studied. The composition of marker compound in HM was found to be 50-60%. The content of curcumnoids, another bioactive constituent present in HM was found to be 0.32-0.55%. The HM was found to be stable at different temperature and pH but light sensitive.

A simple and rapid electrophoretic method to characterize simple phenols, lignans, complex phenols, phenolic acids, and flavonoids in extra-virgin olive oil

We have devised a simple and rapid capillary electrophoretic method which provides the analyst with a useful tool for the characterization of the polyphenolic fraction of extra-virgin olive oil. This method that uses a capillary with 50 microm id and a total length of 47 cm (40 cm to the detector) with a detection window of 100 x 200 microm, and a buffer solution containing 45 mM of sodium tetraborate pH 9.3 offers valuable information about all the families of compounds present in the polar fraction of the olive oil. The detection was carried out by UV absorption at 200, 240, 280, and 330 nm in order to facilitate the identification of the compounds. Concretely, the method permits the identification of simple phenols, lignans, complex phenols (isomeric forms of secoiridoids), phenolic acids, and flavonoids in the SPE-Diol extracts from extra-virgin olive oil in a short time (less than 10 min) and provides a satisfactory resolution. Peak identification was done by comparing both migration time and spectral data obtained from olive oil samples and standards (commercial or isolated (by HPLC-MS) standards), with spiked methanol-water extracts of olive oil with HPLC-collected compounds and commercially available standards at several concentration levels, studying the information of the electropherograms obtained at several wavelengths and also using the information previously reported.

Re-evaluation of peroxide value as an indicator of the quality of edible oils

The oxidation of oils has important effects on the quality of oily foods, such as instant noodles. In particular, the generation of aldehydes, which accompanies the oxidation of oils, is one of the first factors to reduce food quality. We examined various indicators of oil quality during temperature-accelerated storage and found that peroxide value (POV) was highly correlated with the total concentration of major odorants. Moreover, the correlation of POV with the total concentration of five unsaturated aldehydes (t-2-heptenal, t-2-octenal, t-2-decenal, t-2-undecenal and t,t-2,4-decadienal) that show strong cytotoxicity was greater than the correlation of POV with the total concentration of major odorants. The maximum allowable concentration of the five aldehydes was calculated based on the 'no observed adverse-effect level' of the aldehyde that showed the highest cytotoxicity, t,t-2,4-decadienal, along with the human daily oil intake. We showed that it is useful to utilize POV as an indicator to control food quality and safety.

31P NMR spectroscopy in the quality control and authentication of extra-virgin olive oil: a review of recent progress

This review is a brief account on the application of a novel methodology to the quality control and authentication of extra-virgin olive oil. This methodology is based on the derivatization of the labile hydrogens of functional groups, such as hydroxyl and carboxyl groups, of olive oil constituents with the phosphorus reagent 2-chloro-4,4,5,5-tetramethyldioxaphospholane, and the use of the (31)P chemical shifts to identify the phosphitylated compounds. Various experimental aspects such as pertinent instrumentation, sample preparation, acquisition parameters and properties of the phosphorus reagent are reviewed. The strategy to assign the (31)P signals of the phosphitylated model compounds and olive oil constituents by employing 1D and 2D NMR experiments is presented. Finally, the capability of this technique to assess the quality and the genuineness of extra-virgin olive oil and to detect fraud is discussed.

Preparation and characterization of standard reference material 3276, carrot extract in oil

The National Institute of Standards and Technology (NIST), the Food and Drug Administration (FDA) Center for Drug Evaluation and Research (CDER) and Center for Food Safety and Applied Nutrition (CFSAN), and the National Institutes of Health (NIH), Office of Dietary Supplements (ODS) are collaborating to produce a series of standard reference materials (SRMs) for dietary supplements. Standard reference material (SRM) 3276 Carrot Extract in Oil is one in this series, with values assigned for trans-alpha-carotene, trans- and total beta-carotene, delta- and gamma-tocopherol, and twelve fatty acids. Results for carotenoids and tocopherols were obtained by use of combinations of liquid chromatography (LC), on columns of differing selectivity, with absorbance and mass spectrometric (MS) detection. Fluorescence detection also was used for the tocopherols. Results for fatty acids were obtained by use of gas chromatography (GC) with both flame-ionization and mass-spectrometric detection. This material is intended for use as a primary control material when assigning values to in-house (secondary) control materials and for validation of analytical methods for measurement of these analytes in similar matrices.

Membrane Technology in Degumming, Dewaxing, Deacidifying, and Decolorizing Edible Oils

A membrane process offers several advantages over the conventional method of oil refining. Conceptually, membranes could be used in almost all stages of processing. In the present review, various attempts made by the researchers towards degumming, dewaxing, deacidifying, and decolorizing edible oils using membrane technology with and without using solvents have been discussed. Attempts made with UF and nonporous membranes have demonstrated the ability of these membranes to separate phospholipids from undiluted and hexane-diluted oils and a high oil flux was obtained with UF membranes in hexane-diluted oils. MF membranes were very effective for dewaxing undiluted oils while UF membranes were effective in dewaxing hexane-diluted oils without a precooling step. Deacidification was successful only with either addition of an alkali followed by membrane filtration or by following an indirect route of selective solvent extraction of FFA followed by membrane separation. Consistent color reduction in terms of pigments (chlorophyll and xanthophylls) and other instrumental measurements (Lovibond and visible spectra) could be achieved only with nonporous membranes. Interestingly, these membranes did not have selectivity for alpha-and beta-carotenes. UF membranes are best suited for degumming and dewaxing applications, while nonporous membranes appear to be a better choice for achieving simultaneous degumming, dewaxing, and decolorization of oils. Hexane-dilution improved the oil flux of nonporous membranes by one order of magnitude, but further improvement is desirable for industrial adoption.

Lipase production by yeasts from extra virgin olive oil

Newly produced olive oil has an opalescent appearance due to the presence of solid particles and micro-drops of vegetation water from the fruits. Some of our recent microbiological research has shown that a rich micro-flora is present in the suspended fraction of the freshly produced olive oil capable of improving the quality of the oil through the hydrolysis of the oleuropein. Present research however has, for the first time, demonstrated the presence of lipase-positive yeasts in some samples of extra virgin olive oil which can lower the quality of the oil through the hydrolysis of the triglycerides. The tests performed with yeasts of our collection, previously isolated from olive oil, demonstrated that two lipase-producing yeast strains named Saccharomyces cerevisiae 1525 and Williopsis californica 1639 were able to hydrolyse different specific synthetic substrates represented by p-nitrophenyl stearate, 4-nitrophenyl palmitate, tripalmitin and triolein as well as olive oil triglycerides. The lipase activity in S. cerevisiae 1525 was confined to the whole cells, whereas in W. californica 1639 it was also detected in the extracellular fraction. The enzyme activity in both yeasts was influenced by the ratio of the aqueous to the organic phase reaching its maximum value in S. cerevisiae 1525 when the water added to the olive oil was present in a ratio of 0.25% (v/v), whereas in W. californica 1639 the optimal ratio was 1% (v/v). Furthermore, the free fatty acids of olive oil proved to be good inducers of lipase activity in both yeasts. The microbiological analysis carried out on commercial extra virgin olive oil, produced in four different geographic areas, demonstrated that the presence of lipase-producing yeast varied from zero to 56% of the total yeasts detected, according to the source of oil samples. The discovery of lipase-positive yeasts in some extra virgin olive oils leads us to believe that yeasts are able to contribute in a positive or negative way towards the organological quality of the olive oil.

Rapid and quantitative extraction method for the determination of chlorophylls and carotenoids in olive oil by high-performance liquid chromatography

Colour is an organoleptic characteristic of virgin olive oil and an important attribute that affects the consumer perception of quality. Chlorophylls and carotenoids are the main pigments responsible for the colour of virgin olive oil. A simple analytical method for the quantitative determination of chlorophylls and carotenoids in virgin olive oils has been developed. The pigments were isolated from small samples of oil (1.0 g) by solid-phase extraction using diol-phase cartridges (diol-SPE), and the extract was analysed by reverse-phase HPLC with diode-array UV detection. Chromatographic peak resolution, reproducibility (coefficient of variation (C.V.) <4.5%) and recovery (>98.4%) for each component were satisfactory. A comparative study of the proposed method was performed versus classical liquid-liquid extraction (LLE) with N,N'-dimethylformamide and solid-phase extraction using a C18 column (C18-SPE). While 96.4% of the pigments were recovered by LLE, only 51.3% were isolated by C18-SPE in comparison to diol-SPE. Likewise, a higher alteration of pigment composition was observed when such LLE and C18-SPE procedures were used. In this sense, a higher ratio of pheophytin in comparison to that isolated by the diol-SPE procedure was achieved with both extraction procedures, indicating a greater extent of the pheophytinization reaction. Therefore, quantification of pigments from virgin olive oil by diol-SPE followed by RP-HPLC was found to be rapid, simple, required only a small amount of sample, consumed only small amounts of organic solvents, and provided high recoveries, accuracy and precision.

[Study on the supercritical carbon dioxide extraction of Brucea Javanica oil]

The technics of supercritical carbon dioxide extraction of Brucea Javanica for injection oil was studied. The effects of the conditions of extraction and separation on extraction oil yield and quality were investigated and the effects of extraction pressure and separation pressure on acid number of the oil were discussed. So the optimal condition of this method was determined. With a quality evaluation, the Brucea Javanica oil extracted with supercritical CO2 agreed with the quality standard of refined Brucea Javanica oil for injection. This method shows sufficiently the advantages of supercritical CO2 extraction applied in the extraction of traditional Chinese medicine.

Safety evaluation of a lipase enzyme preparation, expressed in Pichia pastoris, intended for use in the degumming of edible vegetable oil

BD16449 lipase is the product of a phospholipid-specific lipase gene expressed in the yeast Pichia pastoris strain DVSA-PLC-004. This type C phospholipid lipase (EC 3.1.4.3) is intended for use in the degumming of edible vegetable oil. BD16449 lipase was tested as a refined test article preparation (DV16449) for its effects on genotoxicity and in acute, inhalation, and subchronic toxicity studies. Dosages ranged from 5000 microg/plate for in vitro toxicity studies to 2000 mg/kg/day for in vivo toxicity studies. The highest oral dose tested in vivo (NOAEL of 2000 mg/kg/day) resulted in a safety margin of 133,000 based on the conservative estimate of the total human consumption of BD16449 lipase of 0.015 mg/kg/day. When adjusted for total organic solids (TOS), the highest oral dose tested in vivo (NOAEL of 1680 mg TOS/kg/day) resulted in a safety margin of 18,300 based on the conservative estimate of the total human consumption of BD16449 lipase of 0.092 mg TOS/kg/day [corrected] There was no toxicity reported for any of these studies including additional safety studies. A review of the literature indicates that P. pastoris fulfills recognized safety criteria pertinent to microbial production strains used in the manufacture of food enzyme preparations. The results of the toxicity studies presented herein attest to the safety of BD16449 lipase for use in the degumming of edible vegetable oil.

Lipolytic activity of Williopsis californica and Saccharomyces cerevisiae in extra virgin olive oil

Inoculation trials performed with three strains of yeasts, isolated from extra virgin olive oil, Williopsis californica 1,639, Saccharomyces cerevisiae 1,525 and Candida boidinii 1,638, demonstrated that some yeast can lower the quality of the oil during storage. Laboratory tests highlighted a substantial increase in the total diglycerides and free fatty acids in the samples of oil inoculated with the lipase-producing strains of yeasts, W. californica 1,639 and S. cerevisiae 1,525, while in the samples of oil inoculated with the lipase-negative strain C. boidinii 1,638 no differences were found in respect to the uninoculated control. The acidity of the extra virgin olive oil, inoculated with the lipase-producing strains W. californica 1,639 and S. cerevisiae 1,525, during 2 weeks of incubation at 30 degrees C increased respectively from 0.62% to 1.50 and 1.62%, exceeding the limit of 0.8% established by current regulations for this commercial category of olive oil, while in the oil inoculated with the lipase-negative strain and in the uninoculated control, the acidity remained constant throughout. Furthermore, the two strains of lipase-producing yeasts also increased the concentration of the 1.3-diglyceride isomer in the oil lowering the values of the total 1.2-diglycerides/total 1.3-diglycerides ratio considered to be an important index of quality for an extra virgin olive oil. The lipolytic activity of lipase-producing strains W. californica 1,639 and S. cerevisiae 1,525 showed an optimum pH of 6 and 7.5 and an optimum temperature of 20 degrees C and 30 degrees C respectively. Nevertheless, the lipolytic activity was negatively influenced by glucose and polyphenols when the concentration was higher than 0.25% and 0.4% (wt/vol) respectively.

Investigations on the effects of rape oil quality, choline and methionine concentration in diets for laying hens on the trimethylamine content of the eggs, on trimethylamine metabolism and on laying performance

An experiment was conducted to study the effects of graded levels of choline addition (0, 500, 1000 and 4000 mg/kg diet) in laying hen diets prepared either with degummed or refined rape oil on the performance, sensory properties and trimethylamine (TMA) contents of the eggs. Furthermore, the diets containing no supplemented choline or 4000mg choline/kg diet were tested with adequate or inadequate methionine supply (4.2 vs. 2.8 g methionine/kg diet). TMA metabolism and N-balance were measured for the latter diet types, but only with the diets containing refined rape oil. Therefore, a total of 12 and 4 diets were tested in the feeding (n = 60) and balance study (n = 9). Laying performance (23 -75 weeks of age) was not significantly influenced by increasing choline additions with the exception of feed-to-egg mass ratio which decreased significantly linearly (P(linear) = 0.003). However, a significant interaction between choline addition and laying month was detected which was caused by a depression of performance of the unsupplemented control group occurring from the sixth laying month. The most obvious effect of an inadequate methionine supply was a temporary drop in performance between the third and sixth laying months. The mean TMA-concentration in pooled egg yolks [microg/g] increased with dietary choline concentration [mg/kg] in an exponentially related fashion (y = 1.14 + 4E(-10) x x(2.71), r2 = 0.962) and suggested only a minor influence of total dietary choline on TMA content up to approximately 2000mg choline/kg. Individual TMA-concentrations varied greatly from 0.4 - 1.5 microg/g, from 2.2 - 34 microg/g and from 18.4 - 75 microg/g for eggs with a normal, aberrant and heavily aberrant odour, respectively. It is concluded that a total choline concentration of at least approximately 1500 mg/kg is necessary to maintain a maximal laying performance. An inadequate methionine supply cannot be compensated by an increased addition of choline. Neither degummed nor refined rape oil influenced the TMA content of eggs.

Direct olive oil authentication: Detection of adulteration of olive oil with hazelnut oil by direct coupling of headspace and mass spectrometry, and multivariate regression techniques

Control of adulteration of olive oil, together with authentication and contamination, is one of the main aspects in the quality control of olive oil. Adulteration with hazelnut oil is one of the most difficult to detect due to the similar composition of hazelnut and olive oils; both virgin olive oil and olive oil are subjected to that kind of adulteration. The main objective of this work was to develop an analytical method able to detect adulteration of virgin olive oils and olive oils with hazelnut oil by means of its analysis by a headspace autosampler directly coupled to a mass spectrometer used as detector (ChemSensor). As no chromatographic separation of the individual components of the samples exists, a global signal of the sample is obtained and employed for its characterization by means of chemometric techniques. Four different crude hazelnut oils from Turkey were employed for the development of the method. Multivariate regression techniques (partial least squares and principal components analysis) were applied to generate adequate regression models. Good values were obtained in both techniques for the parameters employed (standard errors of prediction (SEP) and prediction residual error sum of squares (PRESS)) to evaluate its goodness. With the proposed method, minimum adulteration levels of 7 and 15% can be detected in refined and virgin olive oils, respectively. Once validated, the method was applied to the detection of such adulteration in commercial olive oil and virgin olive oil samples.

Chemometrical classification of pumpkin seed oils using UV-Vis, NIR and FTIR spectra

The main outcome of this work is elaboration of classification models for edible oil samples representing the most widespread brands of Austrian pumpkin seed oil. A complete spectral characterisation of the pumpkin seed oil samples by UV-Vis, NIR and FTIR spectra was obtained together with their basic sensorial classification. Chemometrical processing of the measured data enabled the detection of the most important spectral features, which are crucial for categorising the oils into two or three classes according to their sensory quality evaluated by a panel of experts. The elaborated models thus make it possible to predict the category into which a hitherto unclassified oil sample belongs--considering classification into either two categories, containing oils with overall acceptable scores or oils that were not accepted, or three categories, involving oils fulfilling all quality criteria, oils with good scores and not accepted oils. This will perspectively facilitate the determination of chemical substances responsible for bad taste, odour and colour of the respective oil brands, as well as finding substances contributing to the excellent sensorial perception of some tested products.

[The quality of fat: olive oil]

Olive oil is one of the most characteristic Mediterranean Diet foods, also being a key contributor to the healthy aspects attributed to this dietary pattern. Since 4000 BC, olive oil has been obtained in the Mediterranean area, but now it is exceeding its natural borders, and currently the use of olive oil is a worldwide synonym of health and gastronomic quality. Olive oil has important effects on the body, and has protective effects against several pathologies, i.e. cardiovascular diseases, and various cancers, as well as to diminish the age-related cognitive decline. These effects are due to the olive oil richness in monounsaturated fatty acids and antioxidant substances. Olive oil has been and is the food that define one of the most oldest methods of cooking: frying.