Lutein and zeaxanthin in new dietary supplements—analysis and quantification

Lutein and zeaxanthin, two xanthophylls supposed to delay formation of age-related macular degeneration (AMD), are found in numerous new dietary supplements appearing on the international market. Usually, the lutein concentration ranges from 0.25 to 20 mg/serving size. The lutein contents of 14 products with lutein highlighted on the label were evaluated. Oily formulations were dissolved, and powdery capsule contents were extracted with solvents before high-performance liquid chromatography (HPLC) analysis (diode-array detector, 450 nm) using a C30 column. If lutein diesters from marigold (Tagetes erecta) were present, the extracts were saponified with methanolic KOH. To unequivocally identify carotenoids, HPLC-(atmospheric pressure chemical ionization)mass spectrometry was applied. In this study only all-trans-lutein was quantified, whereas cis isomers (approximately 1–5 area% of total lutein) were not taken into account. The lutein concentration of half of the products investigated was found to be below the amount stated, varying here from 11 to 93%. With the exception of one product, all dietary supplements contained zeaxanthin in amounts typical for the use of marigold oleoresin (6.0±1.4 area% of all-trans-lutein). The high discrepancy found between the amounts labeled and determined in half of the products may be attributed to degradation reactions or to improper storage conditions.     

Likelihood of a marine vessel accident from wind energy development in the Atlantic

Offshore wind energy development is planned for areas off the Atlantic coast. Many of the planned wind development areas fall within traditional commercial vessel routes. In order to mitigate possible hazards to ships and to wind turbines, it is important to understand the potential for increased risk to commercial shipping from the presence of wind farms. Risk is identified as the likelihood that an occurrence will happen, and the consequences of that occurrence, should it occur. This paper deals with the likelihood of commercial vessel accidents, because of the development of offshore wind energy along the US Atlantic coast. Using Automatic Identification System (AIS) data, historical shipping routes between ports in the Atlantic were identified, from Maine to the Florida Straits. The AIS data were also used as inputs to a numerical model that can simulate cargo, tanker and tug/towing vessel movement along typical routes. The model was used to recreate present day vessel movement, as well as to simulate future routing that may be required to avoid wind farms. By comparing the present and future routing of vessels, an analysis of potential maritime accidents was used to determine the increased marginal risk of vessel collisions, groundings and allisions with stationary objects, because of the presence of wind farms. The outcome of the analysis showed little increase in vessel collisions or allisions, and a decrease in groundings as more vessels were forced seaward by the wind farms. Copyright © 2015 John Wiley & Sons, Ltd.     

Adaptive and economic data representation in control architectures of autonomous real-world robots

Learning algorithms for autonomous robots in complex, real-world environments usually have to deal with many degrees of freedom and continuous state spaces. Reinforcement learning is a promising concept for unsupervised learning, but common algorithms suffer from huge storage and calculation requirements if they are used to construct an internal model by estimating a value-function for every action in every possible state. In our attempt to approximate this function at the lowest cost, we introduce a flexible method that focuses on the states of greatest interest, and interpolates between them with a fast and easy-to-implement algorithm. In order to provide the highest accuracy to any predefined limit, we enhanced this algorithm by a fast converging multilayer error approximator. This work was presented in part at the Sixth International Symposium on Artificial Life and Robotics, Tokyo, January 15–17, 2001     

Characterization of the triterpenoid 4,4′-diaponeurosporene and its isomers in food-associated bacteria

4,4'-Diaponeurosporene isomers were identified by LC/MS in extracts obtained from bacteria isolated from food (three strains of Staphylococcus carnosus, Lactobacillus plantarum LTH 4936, and Enterococcus sulfureus DSM 6905^T) as well as from Enterococcus mundtii DSM 4838^T. In addition to the predominant all-trans-isomer, seven cis-isomers of the C30-carotenoid were detected. Triterpenoid carotenoids have not been found before neither in Staphylococci other than Staphylococcus aureus nor in any species of the genus Lactobacillus.     

Diffraction of a general surface wave mode by a surface reactance discontinuity

The scattering of a general hybrid surface wave mode at a reactance discontinuity, on a cylindrical surface waveguide, is considered both theoretically and experimentally. The theory leads to coupled Wiener-Hopf equations, which are solved approximately by assuming the hybrid modes to be mainly TE or TM. The theoretical expressions obtained are evaluated numerically for the symmetrical and dipole modes and compared with experimental results with which substantial agreement is obtained.     

Controlling production dynamics - managing uncertainties with automatic production control

A new dynamic and continuous production model for the planning level, based on methods of control theory, will be presented in this paper. For the control task, a decentral backlog controller has been developed. The controller adjusts the capacity of the individual work system in order to eliminate the backlog as soon as possible. A central WIP-controller secures that only the amount of work that can be handled by means of flexible capacities will be released to the job-shop. The objective is to develop a feedback control for production planning and control with defined control and reference variables based on the logistical objectives.     

Determination of free and bound carotenoids in paprika (Capsicum annuum L.) by LC/MS

Received: 17 August 1999     

Simultaneous determination of the vitamins A, E, their esters and coenzyme Q10 in multivitamin dietary supplements using an RP-C30 phase

A sensitive RP-HPLC method was developed for the simultaneous quantification of the fat-soluble vitamins A, A-acetate, A-palmitate, E, E-acetate and coenzyme Q₁₀ in multivitamin dietary supplements using a C30 phase. Because of the dual-wavelength detection applied, it was possible to monitor vitamins and additionally carotenoids in one run. For identification of vitamins, mass spectra were recorded using LC-(APcI)MS. The vitamins were extracted from 10 commercial dietary supplements (seven soft gel capsules, three tablets) and quantified on the basis of extern calibration graphs. Method performance was studied by addition of vitamin-A- and -E-acetate to a blank matrix: recoveries ranged from 95.7 to 97.8%. On the basis of the amounts labeled, only two products contained substantially lower concentrations of vitamin A-acetate (34% and 46%, respectively). All other concentrations varied between 98% and 245% with respect to vitamin labeling. One product contained vitamin E as alcohol, all other formulations esterified forms of vitamins A and/or E. The presented method may be used by quality assurance laboratories for routine control of nutritional labels.