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Emulsions were prepared with oils (5%w/v) differing in unsaturation degree (olive, soybean or linseed oil) and sucrose ester (0.5%w/v) used as emulsifier. The oils studied were enriched with carotenoids from carrot or tomato purees. All emulsions were in vitro digested and characterised at the level of lipolysis and carotenoid micellarisation kinetics in the small intestinal phase. Olive oil emulsions led to a faster and more extensive lipolysis and carotenoid bioaccessibility compared to soybean and linseed oil emulsions. Monounsaturated fatty acids present in olive oil might be more hydrophobic in comparison to polyunsaturated fatty acids from soybean or linseed oil, leading to micelles with greater capacity of solubilising hydrophobic carotenoids. The obtained results evidence the potential of the oil unsaturation degree for modulating lipolysis and carotenoid bioaccessibility in the gastrointestinal tract and moreover, exemplify the relevance of a kinetic approach including modelling of different lipolysis species to quantitatively prove their interrelation.

In fish processing, a great amount of side streams, including skin, bones, heads and viscera, is wasted or downgraded as feed on a daily basis. These side streams are rich sources of bioactive nitrogenous compounds and protein, which can be converted into peptides through enzymatic hydrolysis as well as bacterial fermentation. Peptides are short or long chains of amino acids differing in structure and molecular weight. They can be considered as biologically active as they can contribute to physiological functions in organisms with applications in the food and pharmaceutical industries. In the food industry, such bioactive peptides can be used as preservatives or antioxidants to prevent food spoilage. Furthermore, peptides contain several functional qualities that can be exploited as tools in modifying food ingredient solubility, water-holding and fat-binding capacity and gel formation. In the pharmaceutical industry, peptides can be used as antioxidants, but also as antihypertensive, anticoagulant and immunomodulatory compounds, amongst other functions. On the basis of their properties, peptides can thus be used in the development of functional foods and nutraceuticals. This review focuses on the bioactive peptides derived from seafood side streams and discusses their technological properties, biological activities and applications.

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Background: There is a growing body of evidence showing that dietary constituents and lipids in particular, influence the function of the human immune system. However, although the beneficial effects of oleic acid (OA) are clear, its mechanism of action at the molecular level is poorly understood. Aims: To evaluate neutrophil activation under the influence of OA and compare this with several n-6 PUFAs. Methods: Two key aspects of neutrophil activation were investigated: oxygen radical (ROS) production and intracellular Ca²⁺ signaling. Results: OA and the n-6 PUFA arachidonic acid (AA) both induced ROS production in a dose-dependent manner, although AA was the more potent stimulus. When looking for the mechanisms behind these effects, we found that both FA induce increases in cytosolic calcium concentration [Ca²⁺]_i), but whereas OA-induced ROS production is totally mediated through Ca2+ signaling, this is not the case for AA since ROS generation by AA is only partly inhibited in BAPTA-treated cells. We also found evidence for the involvement of protein kinase C (PKC) in the OA-induced ROS generation; by contrast, other enzymes apart from PKC seem to be implicated in n-6 PUFA-induced ROS production. In addition, our results argue against the involvement of a pertussis toxin-sensitive receptor activated by OA. Conclusions: OA differs from the n-6 PUFA AA in the activation of human neutrophils and these differences may be related to their distinct inmunomodulatory properties.

Although natural structural barriers are factors limiting nutrient bioaccessibility, their specific role in anthocyanin bioaccessibility is still unknown. To better understand how natural barriers govern bioactive compound bioaccessibility, an experimental approach comparing anthocyanins and carotenoids was designed, using a single plant matrix. Initial results revealed increased anthocyanin bioaccessibility in masticated black carrot. To explain this observation, samples with increasing levels of bioencapsulation (free-compound, homogenized-puree, puree) were examined. While carotenoid bioaccessibility was inversely proportional to the level of bioencapsulation, barrier disruption did not increase anthocyanin bioaccessibility. This means that mechanical processing is of particular importance in the case of carotenoid bioaccessibility. While micelle incorporation is the limiting factor for carotenoid bioaccessibility, anthocyanin degradation under alkaline conditions in the gastrointestinal tract dominates. In the absence of structural barriers, anthocyanin bioaccessibility is greater than that of carotenoids.

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