Colorimetric determination of phospholipids with ammonium ferrothiocyanate
Abstract
Phospholipids may be measured colorimetrically (as dipalmitoyl lecithin) without conventional acid digestion and color development procedures by forming a complex with ammonium ferrothiocyanate.
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Anti-miRNA103/107 encapsulated in transferrin-conjugated lipid nanoparticles crosses blood-brain barrier and reduces brain ischemic damage
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One-step separation of fat globules based on size from bovine milk using a cross-flow microfiltration
2024, Separation and Purification TechnologyMilk microfiltration has gained attention in the dairy industry due to its ability to selectively separate and concentrate bioactive components from milk and its further application in food fortification. One such compound is milk fat globules, a bioactive component with potential health benefits, which undergoes structural and functional damage, membrane phospholipids loss, experience longer processing time, and higher recovery cost due to its current multi-step separation process. We developed a single-step approach based on size for the separation of smaller-size milk fat globules from cow and buffalo milk using a porous polysulfone membrane through a cross-flow microfiltration system. An asymmetric polysulfone membrane with an average pore size of 0.8 ± 0.03 µm was synthesized via phase inversion and subsequently characterized for surface morphology, hydrophilicity, porosity, thermo-mechanical properties, and water contact angle. The membrane demonstrated good performance, with initial milk permeate flux ranging from 296 to 613 L/m2h at different transmembrane pressures (e.g., 0.2, 0.4, 0.6 bar) for both animal groups, with a gradual decline due to concentration polarization, and eventually reaching a steady state. Notably, at lower transmembrane pressure, the membrane exhibited excellent antifouling properties (flux recovery of 81.56–83 %) and reusability over three cycles. Microscopic examination of milk fat globules confirmed the successful size-based separation with intact globule membrane, high phospholipid yield, and mass balance. The results, to the best of our knowledge, demonstrate for the first time an in-depth analysis of membrane fouling and reusability for selective isolation of milk fat globules.
Impact of frozen storage on quality and cold storage stability of smoked deep-skinned fillets from well-fed Atlantic mackerel
2024, Journal of Food Composition and AnalysisTo ensure year-round availability and stability of Atlantic mackerel caught in Icelandic waters during summer after intensive feeding, freezing is essential. Due to the high lipid content and sensitive lipid composition of the fish caught at this time, the fish industry requires detailed research to understand the mechanisms underlying the degradation processes occurring during storage and processing, in order to develop high-value hot-smoked products. Therefore, the impact of frozen storage at − 25 ± 1.8 °C (for 6, 9, and 20 months) prior to hot-smoking, was investigated on the physicochemical, microbial, and sensory quality of deep-skinned, smoked fillets from well-fed Atlantic mackerel caught in late August. The stability of hot-smoked fillets stored at 1 ± 0.6 °C was then monitored for 28 days. Total aerobic viable counts (TVC) remained below acceptable thresholds due to the combined effects of brining, freezing, and hot-smoking, while Listeria monocytogenes was not detected in the hot-smoked products. Slow formation of oxidation products was observed during the chilled storage, especially in the fish frozen for 9 months. Minor lipid deterioration was also detected during sensory analysis, but all spoilage indices remained within acceptable thresholds for shelf-life. Frozen storage for up to 20 months thus effectively maintained the sensory acceptability and suitability of deep-skinned mackerel fillets, making them an excellent choice for the fish-smoking industry.
Interactions between CuO NPs and PS: The release of copper ions and oxidative damage
2023, Science of the Total EnvironmentCopper oxide nanoparticles (CuO NPs) can adversely affect lung health possibly by inducing oxidative damage through the release of copper ions. However, the migration and transformation processes of CuO NPs in lung lining fluid is still unclear, and there are still conflicting reports of redox reactions involving copper ions. To address this, we examined the release of copper ions from CuO NPs in simulated lung fluid supplemented with pulmonary surfactant (PS), and further analyzed the mechanisms of PS-CuO NPs interactions and the health hazards. The results showed that the phospholipid of PS was adsorbed on the particle surface, which not only induced aggregation of the particles but also provided a reaction environment for the interaction of PS with CuO NPs. PS was able to promote the release of ions from CuO NPs, of which the protein was a key component. Lipid peroxidation, protein destabilization, and disruption of the interfacial chemistry also occurred in the PS-CuO NPs interactions, during which copper ions were present only as divalent cations. Meanwhile, the contribution of the particle surface cannot be neglected in the oxidative damage to the lung caused by CuO NPs. Through reacting with biomolecules, CuO NPs accomplished ion release and induced oxidative damage associated with PS. This research was the first to reveal the mechanism of CuO NPs releasing copper ions and inducing lipid oxidative damage in the presence of PS, which provides a new idea of transition metal-induced health risk in human body.