Development of a novel continuous statistical modelling technique for detecting the adulteration of extra virgin olive oil with hazelnut oil by using spectroscopic data

The adulteration of extra virgin olive oil with other vegetable oils is a certain problem with economic and health consequences. Current official methods have been proved insufficient to detect such adulterations. One of the most concerning and undetectable adulterations with other vegetable oils is the addition of hazelnut oil. The main objective of this work was to develop a novel dimensionality reduction technique able to model oil mixtures as a part of an integrated pattern recognition solution. This final solution attempts to identify hazelnut oil adulterants in extra virgin olive oil at low percentages based on spectroscopic chemical fingerprints. The proposed Continuous Locality Preserving Projections (CLPP) technique allows the modelling of the continuous nature of the produced in house admixtures as data series instead of discrete points. This methodology has potential to be extended to other mixtures and adulterations of food products. The maintenance of the continuous structure of the data manifold lets the better visualization of this examined classification problem and facilitates a more accurate utilisation of the manifold for detecting the adulterants.

Virgin Olive Oil: Losses of Antioxidant Polar Phenolic Compounds due to Storage, Packaging, and Culinary Uses

Virgin olive oil is a high quality natural product obtained only by physical means. In addition to triacylglycerols it contains nutritionally important polar and non-polar antioxidant phenols and other bioactive ingredients. The polar fraction is a complex mixture of phenolic acids, simple phenols, derivatives of the glycosides oleuropein and ligstroside, lignans, and flavonoids. These compounds contribute significantly to the stability, flavor, and biological value of virgin olive. In the various stages of production, during storage and in the culinary uses, polar phenols and other valuable bioactive ingredients may be damaged. Oxidation, photo-oxidation, enzymic hydrolysis and heating at frying temperatures have a serious adverse effect. Due to the biological importance of the oil and its unique character, analytical methods have been developed to evaluate antioxidant activity or analyse complex phenol mixtures. These are based on radical scavenging assays and chromatographic techniques. Hyphenated methods are also used including liquid chromatography-mass spectrometry and liquid chromatography-nuclear magnetic resonance spectroscopy.

Continuous statistical modelling for rapid detection of adulteration of extra virgin olive oil using mid infrared and Raman spectroscopic data

The main objective of this work was to develop a novel dimensionality reduction technique as a part of an integrated pattern recognition solution capable of identifying adulterants such as hazelnut oil in extra virgin olive oil at low percentages based on spectroscopic chemical fingerprints. A novel Continuous Locality Preserving Projections (CLPP) technique is proposed which allows the modelling of the continuous nature of the produced in-house admixtures as data series instead of discrete points. The maintenance of the continuous structure of the data manifold enables the better visualisation of this examined classification problem and facilitates the more accurate utilisation of the manifold for detecting the adulterants. The performance of the proposed technique is validated with two different spectroscopic techniques (Raman and Fourier transform infrared, FT-IR). In all cases studied, CLPP accompanied by k-Nearest Neighbors (kNN) algorithm was found to outperform any other state-of-the-art pattern recognition techniques.

The contents of proteins and phospholipids in cloudy (veiled) virgin olive oils

Extra virgin olive oil is produced in the form of a

Evaluation of methodologies to determine vegetable oil species present in oil mixtures: Proposition of an approach to meet the EU legislation demands for correct vegetable oils labelling

Refined vegetable oils are widely used in the food industry as ingredients or components in many processed food products in the form of oil blends. To date, the generic term 'vegetable oil' has been used in the labelling of food containing oil blends. With the introduction of new EU Regulation for Food Information (1169/2011) due to take effect in 2014, the oil species used must be clearly identified on the package and there is a need for development of fit for purpose methodology for industry and regulators alike to verify the oil species present in a product. The available methodologies that may be employed to authenticate the botanical origin of a vegetable oil admixture were reviewed and evaluated. The majority of the sources however, described techniques applied to crude vegetable oils such as olive oil due to the lack of refined vegetable oil focused studies. Nevertheless, DNA based typing methods and stable isotopes procedures were found not suitable for this particular purpose due to several issues. Only a small number of specific chromatographic and spectroscopic fingerprinting methods in either targeted or untargeted mode were found to be applicable in potentially providing a solution to this complex authenticity problem. Applied as a single method in isolation, these techniques would be able to give limited information on the oils identity as signals obtained for various oil types may well be overlapping. Therefore, more complex and combined approaches are likely to be needed to identify the oil species present in oil blends employing a stepwise approach in combination with advanced chemometrics. Options to provide such a methodology are outlined in the current study.

Identifying oil species in oil mixtures

Detection of adulteration of non-processed vegetable oil with lesser value seed oils (classic example is hazelnut in virgin olive oil) has been in the centre of scientific attention for many years and several chemical methods were proposed. The recent EC Regulation 1169/2011, however, introduces necessity for different analytical method in a more complicated matrix. From the end of 2014, food businesses required to declare the composition of the refined oil mixture in the food product label. This creates a gap since there is no analytical method currently available to perform such analysis. In the first phase the work focused on 100% oil blends of various oil species of palm oil (and derivatives), sunflower and rapeseed oil before expanding to foodstuffs. Chromatographic methods remain highly relevant although suffer from various limitations which derive from natural compositional variation. Modern multivariate techniques based on machine learning algorithms, however, when applied in FTIR, Raman spectroscopic data have a strong potential in tackling the problem.

The application of calcined natural dolomitic rock as a solid base catalyst in triglyceride transesterification for biodiesel synthesis

Natural dolomitic rock has been investigated in the transesterification of C-4 and C-8 triglycerides and olive oil with a view to determining its viability as a solid base catalyst for use in biodiesel synthesis. XRD reveals that the dolomitic rock comprised 77% dolomite and 23% magnesian calcite. The generation of basic sites requires calcination at 900 degrees C, which increases the surface area and transforms the mineral into MgO nanocrystallites dispersed over CaO particles. Calcined dolomitic rock exhibits high activity towards the liquid phase transesterification of glyceryl tributyrate and trioctanoate, and even olive oil, with methanol for biodiesel production.

Platelet Redox Balance in Diabetic Patients with Hypertension improved by n-3 fatty acids

OBJECTIVE:
Patients with type 2 diabetes mellitus (T2DM) are at increased risk of developing cardiovascular disease, largely as a result of defective production of cardioprotective nitric oxide and a concomitant rise in oxidative stress. Dietary interventions that could reverse this trend would be extremely beneficial. Here we investigated whether dietary n-3 polyunsaturated fatty acid (n-3 PUFA) supplementation positively affected platelet nitroso-redox imbalance.
RESEARCH DESIGN AND METHODS:
We randomized hypertensive T2DM patients (T2DM HT; n = 22) and age-and-sex matched hypertensive study participants without diabetes (HT alone; n = 23) in a double-blind, crossover fashion to receive 8 weeks of n-3 PUFAs (1.8 g eicosapentaenoic acid and 1.5 g docosahexaenoic acid) or identical olive oil capsules (placebo), with an intervening 8-week washout period. Platelet nitrite and superoxide were measured and compared before and after treatment; 8-isoprostane was determined by ELISA and subcellular compartmentalization of the NAD(P)H oxidase subunit p47-phox examined by Western blotting.
RESULTS:
The n-3 PUFA supplementation reduced 8-isoprostane and superoxide levels in platelets from T2DM HT, but not HT alone, participants, without effect on nitrite production. This coincided with a significant decrease in p47-phox membrane localization and a similar reduction in superoxide to that achieved with apocynin. At baseline, a subcohort of T2DM HT and HT alone participants showed evidence of nitric oxide synthase (NOS)-derived superoxide production, indicating defective enzymatic activity. This was reversed significantly in T2DM HT participants after treatment, demonstrating improved NOS function.
CONCLUSIONS:
Our finding that n-3 PUFAs diminish platelet superoxide production in T2DM HT patients in vivo suggests a therapeutic role for these agents in reducing the vascular-derived oxidative stress associated with diabetes.

A posteriori-derived dietary patterns and retinal vessel caliber in an elderly population

Purpose. To examine the association between a posteriori–derived dietary patterns (DP) and retinal vessel caliber in an elderly population.

Methods. This was a cross-sectional study of 288 elderly adults (>65 years) who participated in the European Eye study (EUREYE) Northern Irish cohort. DP were extracted using principal component analysis from completed food frequency questionnaires. Semi-automated computer grading was used to determine the mean retinal vessel diameters (central retinal arteriole equivalent [CRAE] and central retinal venule equivalent [CRVE]) from digitized visual field one images using a standard measurement protocol.

Results. Three major DP were identified in this population, which accounted for 21% of the total variance: a “healthy” pattern with high factor loadings for oily fish, fruits and vegetables, and olive oil; an “unhealthy” pattern with high factor loadings for red and processed meat, refined grains, eggs, butter, sugar and sweets; and a “snack and beverage” pattern with high factor loading for pizza, nuts, and coffee. Multivariable linear regression analysis indicated no significant association between major identified DP and mean CRAE or CRVE in all models.

Conclusions. This is the first study to investigate associations between a posteriori–derived DP and retinal vessel caliber. There was no evidence of a relationship between extracted DP and retinal vessel measurements in this population. However, it is possible that potentially important relationships exist between single nutrients or foods and vessel diameters that cannot be identified using a DP approach. Further studies to examine the role of dietary factors in the microcirculation are required.

Session 4: CVD, diabetes and cancer - Evidence for the use of the Mediterranean diet in patients with CHD

Diet is associated with the development of CHD. The incidence of CHD is lower in southern European countries than in northern European countries and it has been proposed that this difference may be a result of diet. The traditional Mediterranean diet emphasises a high intake of fruits, vegetables, bread, other forms of cereals, potatoes, beans, nuts and seeds. It includes olive oil as a major fat source and dairy products, fish and poultry are consumed in low to moderate amounts. Many observational studies have shown that the Mediterranean diet is associated with reduced risk of CHD, and this result has been confirmed by meta-analysis, while a single randomised controlled trial, the Lyon Diet Heart study, has shown a reduction in CHD risk in subjects following the Mediterranean diet in the secondary prevention setting. However, it is uncertain whether the benefits of the Mediterranean diet are transferable to other non-Mediterranean populations and whether the effects of the Mediterranean diet will still be feasible in light of the changes in pharmacological therapy seen in patients with CHD since the Lyon Diet Heart study was conducted. Further randomised controlled trials are required and if the risk-reducing effect is confirmed then the best methods to effectively deliver this public health message worldwide need to be considered.

Exploring molecular recognition pathways within a family of gelators with different hydrogen bonding motifs

We report the synthesis of a family of gelators in which alkyl chains are connected to the amino groups of L-lysine methyl ester using a range of different hydrogen bonding linking groups (carbamate, amide, urea, thiourea and diacylhydrazine) using simple synthetic methodology based on isocyanate or acid chloride chemistry. The ability of these compounds to gelate organic solvents such as toluene or cyclohexane can be directly related to the ability of the linking group to form intermolecular hydrogen bonds. In general terms, the ability to structure solvents can be considered as: thiourea <carbamate <amide <urea similar to diacylhydrazine. This process has been confirmed by thermal measurements, scanning electron microscopy (SEM) and infrared and circular dichroism spectroscopies. By deprotecting the methyl ester group, we have demonstrated that a balance between hydrophobic and hydrophilic groups is essential-if the system has too much hydrophilicity (e. g., diacylhydrazine, urea) it will not form gels due to low solubility in the organic media. However, the less effective gelators based on amide and carbamate linkages are enhanced by converting the methyl ester to a carboxylic acid. Furthermore, subsequent mixing of the acid with a second component (diaminododecane) further enhances the ability to form networks, and, in the case of the amide, generates a two-component gel, which can immobilise a wide range of solvents of industrial interest including petrol and diesel (fuel oils), olive oil and sunflower oil (renewable food oils) and ethyl laurate, isopropyl myristate and isopropyl palmitate (oils used in pharmaceutical formulation). The gels are all thermoreversible, and may therefore be useful in controlled release/formulation applications.

Characterisation of UK and Irish Cold-Pressed Rapeseed Oils in Relation to Quality Indices and Constituents.

Cold-pressed rapeseed oil (CPRSO) is produced when seeds from an oilseed rape crop are mechanically crushed whilst at a low temperature. CPRSO’s popularity is rapidly expanding and is now produced in most Northern European countries including both N.Ireland and ROI. The CPRSO industry is still relatively new and therefore not as widely researched as other high quality oils. Fifteen CPRSO from The UK, Ireland and France were examined to determine characteristic differences between the oils. Two samples of extra-virgin olive oil and two samples of refined rapeseed oil were also included in the investigation to assess performance against market competitors. The antioxidant potential of the oils was assessed using the ABTS and DPPH radical scavenging assays. Both unexpectedly showed that refined rapeseed oil had the highest potential whilst there was significant difference between many of the CPRSO’s. The acid value (ACOS method Cd 3d-63) ranged widely from 0.47-3.41. To predict the stability during storage, an accelerated oxidation test was carried out where the oils were placed in an oven (60°C) and peroxide value was monitored. The results showed extra-virgin olive oil underwent the least oxidation during the trial. The refined rapeseed oil suffered the worst levels of oxidation whilst the CPRSO’s performed similarly but with some variation. Fatty acid composition was investigated with GC-MS and some of the major fatty acids were found to differ significantly between producers. Minor compound analysis was achieved with extraction and identification through HPLC. All results are critically discussed and compared to relevant published studies.