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.

Dimensionality, Reliability and Validity of the InterRAI Depression Rating Scale in a Canadian Palliative Care Population

A reliable and valid instrument is needed to screen for depression in palliative patients. The interRAI Depression Rating Scale (DRS) is based on seven items in the interRAI Palliative Care instrument. This study is the first to explore the dimensionality, reliability and validity of the DRS in a palliative population. Palliative home care patients (n = 5,175) residing in Ontario (Canada) were assessed with the interRAI Palliative Care instrument. Exploratory factor analysis and Mokken scale analysis were used to identify candidate conceptual models and evaluate scale homogeneity/performance. Confirmatory factor analysis compared models using standard goodness-of-fit indices. Convergent and divergent validity were investigated by examining polychoric correlations between the DRS and other items. The “known groups” test determined if the DRS meaningfully distinguished among client subgroups. The non-hierarchical two factor model showed acceptable fit with the data, and ordinal alpha coefficients of 0.83 and 0.82 were observed for the two DRS subscales. Omega hierarchical (ωh) was 0.78 for the bifactor model, with the general factor explaining three quarters of the common variance. Despite the multidimensionality evident in the factor analyses, bifactor modelling and the Mokken homogeneity coefficient (0.34) suggest that the DRS is a coherent scale that captures important information on sub-constructs of depression (e.g., somatic symptoms). Higher correlations were seen between the DRS and mood and psychosocial well-being items, and lower correlations with functional status and demographic variables. The DRS distinguished in the expected manner for known risk factors (e.g., social support, pain). The results suggest that the DRS is primarily unidimensional and reliable for use in screening for depression in palliative care patients.

Identification of vegetable oil botanical speciation in refined vegetable oil blends using an innovative combination of chromatographic and spectroscopic techniques

European Regulation 1169/2011 requires producers of foods that contain refined vegetable oils to label the oil types. A novel rapid and staged methodology has been developed for the first time to identify common oil species in oil blends. The qualitative method consists of a combination of a Fourier Transform Infrared (FTIR) spectroscopy to profile the oils and fatty acid chromatographic analysis to confirm the composition of the oils when required. Calibration models and specific classification criteria were developed and all data were fused into a simple decision-making system. The single lab validation of the method demonstrated the very good performance (96% correct classification, 100% specificity, 4% false positive rate). Only a small fraction of the samples needed to be confirmed with the majority of oils identified rapidly using only the spectroscopic procedure. The results demonstrate the huge potential of the methodology for a wide range of oil authenticity work.

Varieties of resource nationalism in sub-Saharan Africa’s energy and minerals markets

This article examines resource nationalism in sub-Saharan Africa's energy and minerals markets. It does so by exploring economic and political developments in three cases: Nigeria as an example of a petro-state established by means of expropriation in the wake of decolonisation; South Africa, a mature mining industry shaped by its settler colonial history; and Mozambique, a new and therefore highly-dependent entrant into the league of significant natural gas producers. Extractive industries have played a controversial role in sub-Saharan Africa due in particular to the prevalence of the resource curse. Nevertheless, energy exports will continue to play an important role in fuelling economic growth and, potentially, also development as new deposits of natural gas and oil are discovered across the region. Resource nationalism has, moreover, increasingly constrained operations of the traditionally dominant Western energy companies, in particular as competition from state-owned energy companies in sub-Saharan Africa and from emerging powers such as China is increasing.

A new analytical approach for the detection of palm oil in vegetable oil blends

The new Food Information Regulation (1169/2011), dictates that in a refined vegetable oil blend, the type of oil must be clearly identified in the package in contract with current practice where is labelled under the generic and often misleading term “vegetable oil”. With increase consumer awareness in food authenticity, as shown in the recent food scandal with horsemeat in beef products, the identification of the origin of species in food products becomes increasingly relevant. Palm oil is used extensively in food manufacturing and as global demand increases, producing countries suffer from the aftermath of intensive agriculture. Even if only a small portion of global production, sustainable palm oil comes in great demand from consumers and industry. It is therefore of interest to detect the presence of palm oil in food products as consumers have the right to know if it is present in the product or not, mainly from an ethical point of view. Apart from palm oil and its derivatives, rapeseed oil and sunflower oil are also included. With DNA-based methods, the gold standard for the detection of food authenticity and species recognition deemed not suitable in this analytical problem, the focus is inevitably drawn to the chromatographic and spectroscopic methods. Both chromatographic (such as GC-FID and LC-MS) and spectroscopic methods (FT-IR, Raman, NIR) are relevant. Previous attempts have not shown promising results due to oils’ natural variation in composition and complex chemical signals but the suggested two-step analytical procedure is a promising approach with very good initial results.

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.

Active Controllers or Wealthy Rentiers?: Large Shareholders in Victorian Public Companies

This article addresses the issue of whether large shareholders in Victorian public companies were active in the control of companies or were simply wealthy rentiers. Using ownership records for 890 firm-years, we examine the control rights, socio-occupational background, and wealth of large shareholders. We find that many large shareholders had limited voting rights and neither they nor family members were directors. This implies that the majority of public companies in the second half of the nineteenth century cannot be characterized as family companies and that large shareholders are better viewed as wealthy gentlemen capitalists rather than entrepreneurs.

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.

An analysis of implied volatility jump dynamics: Novel functional data representation in crude oil markets

The predominant fear in capital markets is that of a price spike. Commodity markets differ in that there is a fear of both upward and down jumps, this results in implied volatility curves displaying distinct shapes when compared to equity markets. The use of a novel functional data analysis (FDA) approach, provides a framework to produce and interpret functional objects that characterise the underlying dynamics of oil future options. We use the FDA framework to examine implied volatility, jump risk, and pricing dynamics within crude oil markets. Examining a WTI crude oil sample for the 2007–2013 period, which includes the global financial crisis and the Arab Spring, strong evidence is found of converse jump dynamics during periods of demand and supply side weakness. This is used as a basis for an FDA-derived Merton (1976) jump diffusion optimised delta hedging strategy, which exhibits superior portfolio management results over traditional methods.

Hydroprocessing of waste cooking oil over a dispersed nano catalyst: Kinetics study and temperature effect

The kinetics of hydrodeoxygenation of waste cooking oil (WCO) is investigated with unsupported CoMoS catalysts. A kinetic model is established and a comprehensive analysis of each reaction pathway is carried out. The results show that hydrodecarbonylation/decarboxylation (HDC) routes are the predominant reaction pathways in the elimination of oxygen, with the rate constant three times as high as that of hydrodeoxygenation (HDO). However, the HDC activity of the CoMoS catalyst deactivates due to gradual loss of sulfur from the catalyst. HDO process is insensitive to the sulfur deficiency. The kinetic modeling shows that direct hydrodecarbonylation of fatty acids dominates the HDC routes and, in the HDO route, fatty acids are transferred to aldehydes/alcohols and then to C-18 hydrocarbons, a final product, and the reduction of acids is the rate limiting step. The HDO route via alcohols is dominant over aldehydes due to a significantly higher reaction rate constant. The difference of C-18/C-17 ratio in unsupported and supported catalysts show that a support with Lewis acid sites may play an important role in the selectivity for the hydrodeoxygenation pathways and promoting the final product quality