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The highly hydrophobic β‐carotene is often distributed or dissolved in triglycerides to enhance either nutritional or coloring effects. This study aims at elucidating the physical state of β‐carotene that at high concentrations are mixed into a solid high‐melting tri‐glyceride matrix by dissolution at high temperatures (165 °C) in the melted triglyceride. Extensive isomerization of β‐carotene is observed by HPLC after melting crystalline all‐trans β‐carotene and in the solid mixtures of β‐carotene and fully hydrogenated sunflower oil. Crystalline triglyceride is found in the mixed samples by XRPD analysis whereas no signs of crystalline lattice structures of β‐carotene are detected. DSC thermograms show only the melting and recrystallization events of triglycerides, which are affected by the presence of β‐carotene. Severe line broadening is observed in the ¹³C CP/MAS NMR spectra of the β‐carotene‐triglyceride mixtures when compared to crystalline β‐carotene, demonstrating the lack of long‐range order of the carotene. Altogether, the results demonstrate that β‐carotene is present as an amorphous mixture of trans‐ and cis‐isomers dispersed into a structure of crystalline triglyceride in the solid carotene‐triglyceride mixtures. Practical applications: The amorphous structure of trans‐ and cis‐isomers in solid formulations of β‐carotene‐triglyceride mixtures will strongly affect their functional properties related to nutrition and color as food ingredients.

Aim Geographic mapping of risks is a useful analytical step in ecological risk assessments and in particular, in analyses aimed to estimate risks associated with introductions of invasive organisms. In this paper, we approach invasive species risk mapping as a portfolio allocation problem and apply techniques from decision theory to build an invasion risk map that combines risk and uncertainty in a single map product. Location Canada. Methods We divide the study area into a set of spatial domains and treat each domain as an individual ‘portfolio’ with a unique distribution of the expected impacts of invasion. The risk of invasion is then mapped by finding nested ‘efficient’ portfolio sets that identify the geographic areas exhibiting the worst combinations of the estimated risk of invasion and the uncertainty in that estimate. For Canadian municipalities, we apply the approach to quantify the risk that a given location will receive invasive forest pests with commercial freight transported via the North American road network. We compare risk allocation techniques that employ the concepts of nested mean-variance (M-V) frontiers and second-degree stochastic dominance. Results While both methods based on M-V and the stochastic dominance principles identified similar areas of highest risk, they differed in how they demarcated moderate-risk areas. Furthermore, they address uncertainty in different ways, treating it as a risk premium (in the case of nested M-V frontiers) or producing risk-averse delineations (in the case of stochastic dominance). Main conclusions The portfolio-based approach offers a viable strategy for dealing with the typically wide variability in risk estimates caused by a lack of knowledge about a new invader. The methodology also provides a tractable way of incorporating decision-making preferences into the final risk estimates and thus better aligns risk assessments with particular decision-making scenarios about the organism of concern.

Aim Uncertainty has been widely recognized as one of the most critical issues in predicting the expansion of ecological invasions. The uncertainty associated with the introduction and spread of invasive organisms influences how pest management decision makers respond to expanding incursions. We present a model-based approach to map risk of ecological invasions that combines two potentially conflicting goals: (1) estimating the likelihood of a new organism being established at a given locale and (2) quantifying the uncertainty of that prediction. Location Eastern and central Canada. Methods Our methodology focuses on the potential for long-distance, humanassisted spread of invasive organisms. First, we used a spatial simulation model to generate distributions of plausible invasion outcomes over a target geographical region. We then used second-degree stochastic dominance (SSD) criteria to rank all geographical locations in the target region based on these distributions. We applied the approach to analyze pathways of human-assisted spread (i.e., with commercially transported goods) of the emerald ash borer (EAB) (Agrilus planipennis Fairmaire), a major pest of ash trees in North America. Results The projected potential of the pest to establish at remote locations is significantly shaped by the amount of epistemic uncertainty in the model-based forecasts. The estimates based on the SSD ranking identified major ‘crossroads’ through which the movement of the EAB with commercial transport is most likely to occur. The system of major expressways in Ontario and Quebec was confirmed as the primary gateway of the pest’s expansion throughout the Canadian landscape. Main conclusions Overall, the new approach generates more realistic predictions of long-distance introductions than models that do not account for severe uncertainties and thus can help design more effective pest surveillance programmes. The modelling technique is generic and can be applied to assess other environmental phenomena when the level of epistemic uncertainty is high.

Heterogeneous palladium catalysts are highly active for Suzuki coupling reactions in neat water and in the presence of tetrabutylammonium bromide under mild conditions.