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Carotenoid bioavailability from plant and animal food is highly variable depending on numerous factors such as the physical deposition form of carotenoids. As the carotenoid zeaxanthin is believed to play an important role in eye and brain health, we sought to compare the human bioavailability of an H-aggregated with that of a J-aggregated deposition form of zeaxanthin encapsulated into identical formulation matrices. A randomised two-way cross-over study with sixteen participants was designed to compare the post-prandial bioavailability of an H-aggregated zeaxanthin and a J-aggregated zeaxanthin dipalmitate formulation, both delivering 10 mg of free zeaxanthin. Carotenoid levels in TAG-rich lipoprotein fractions were analysed over 9·5 h after test meal consumption. Bioavailability from the J-aggregated formulation (AUC=55·9 nmol h/l) was 23 % higher than from the H-aggregated one (AUC=45·5 nmol h/l), although being only marginally significant (P=0·064). Furthermore, the same formulations were subjected to an internationally recognised in vitro digestion protocol to reveal potential strengths and weaknesses of simulated digestions. In agreement with our human study, liberation of zeaxanthin from the J-aggregated formulation into the simulated duodenal fluids was superior to that from the H-aggregated form. However, micellization rate (bioaccessibility) of the J-aggregated zeaxanthin dipalmitate was lower than that of the H-aggregated zeaxanthin, being contradictory to our in vivo results. An insufficient ester cleavage during simulated digestion was suggested to be the root cause for these observations. In brief, combining our in vitro and in vivo observations, the effect of the different aggregation forms on human bioavailability was lower than expected.
A student of Carl Linnaeus, Pehr Osbeck (1723–1805) was a Swedish explorer, naturalist and chaplain. He travelled to Asia in 1750–2 and brought back some six hundred specimens that were included in Linnaeus' Species Plantarum (1753). His account of his voyage was published in Swedish in 1757, in German in 1765, and here in English in 1771, edited and translated by Johann Reinhold Forster (1729–98). This two-volume work also includes letters to Linnaeus by another pupil, Olof Torén (1718–53), who also travelled to the East in the early 1750s, as well as a paper on Chinese husbandry by Carl Gustaf Ekeberg (1716–84). Ekeberg made ten trips to China and India between 1742 and 1778, becoming a captain in the Swedish East India Company. He too brought back numerous specimens for Linnaeus. Volume 2 contains the conclusion of Osbeck's account, the pieces by Torén and Ekeberg, and a catalogue of animals and plants native to China.