Mechanisms for the interaction of the milk fat globule membrane with the plasma membrane of gut epithelial cells.

The milk fat globule membrane (MFGM) provides infants and adults with several health benefits. These are not derived solely from its unique composition, but also from arrangement of lipids in the MFGM that, in the case of newborns, could reach the intestine partially intact. Fluorochromes associated with lipid derivatives were used to prove a fusion process between the MFGM and the cellular membrane of differentiated Caco-2 cells. To explore the mechanism of this interaction, incubations of MFGM with Caco-2 cells were carried out in the presence of fusogenic agents or compounds that block other MFGM interaction pathways with cells. Confocal fluorescence microscopy provided visual evidence of the fusion process. Lastly, determination on the lipid profile of cells after their interaction with MFGM indicated a metabolic rearrangement of lipids leading to accumulation of triacylglycerols.

Food matrix impacts bioaccessibility and assimilation of acid whey-derived milk fat globule membrane lipids in Caco-2 cells.

The milk fat globule membrane (MFGM) imparts human health benefits ranging from improved immune system, gut, and brain function to improved cardiometabolic health. The industry's growing interest in introducing MFGM-enriched foods requires scientific evidence that the benefits derived from this compound are not affected by the formulation or processes that may alter its function, such as the digestion process. In this study, the impact of food matrices and supplementation levels on the bioaccessibility and assimilation of MFGM lipids in cell culture was investigated. Three food matrices including a protein-rich jelly, carbohydrate-rich cookie, and a carbohydrate- and fat-rich cookie with sunflower oil (SF-cookie) were supplemented with an MFGM ingredient derived from cottage cheese acid whey at 2, 5, and 10% (w/w). Each formulation underwent simulated digestion consisting of oral, gastric, and intestinal phases, and the micellar fraction was collected for both analysis and lipid assimilation in Caco-2 intestinal cells. The micellar fractions were diluted and applied to the cells for 4 h. A lipidomic approach was used to assess the lipid profiles of micellar fractions and intestinal cells. The micelles from digested jellies, cookies, and SF-cookies containing MFGM showed a distinct separation using partial least squares discriminant analysis (PLS-DA). Both correlation loadings and variable importance in projection (VIP) scores demonstrated a tendency of MFGM polar lipids (ceramides, glucosylceramides) for micelles from digested jelly, whereas micelles from digested cookies were associated with MFGM neutral lipids (free fatty acids, cholesterol, etc.). The effect of supplementation level on the micellar lipid profiles reinforced this pattern. The lipid profiles of intestinal cells after incubation with the micellar fractions differed considerably from the corresponding micellar lipid profiles. Specifically, the SF-cookie-treated cells were associated with a greater abundance of PUFA relative to jelly- and cookie-treated cells; however, increasing MFGM supplementation showed irregular patterns and rearrangement of cellular lipid profiles, suggesting the cells' role in regulating lipid metabolism in response to nutritional stimuli. The nature of lipid micellarization and assimilation in intestinal cells from MFGM-containing food formulations echoes the complexity of lipids inherent to the MFGM itself, suggesting the need for application-based MFGM supplementation.

Comprehensive chlorophyll composition of commercial green food colorants and coloring foodstuffs by HPLC-ESI-QTOF-MS/MS: Chlorophyllins.

Consumers demand higher levels of food quality and safety, so food legislative organizations need full knowledge of food composition to develop regulations that guarantee quality and safety criteria. This is the context for green natural food colorants and the new category green "coloring foodstuffs". We have exploited the capabilities of targeted metabolomics assisted by powerful software and algorithms to unravel the comprehensive chlorophyll composition in commercial samples of both colorant categories. With the aid of an in-house library, at first, seven new chlorophylls have been identified, among all the samples analyzed, providing data on their structural configuration. Next, taking advantage of an expert-curated database, eight more chlorophylls non-described previously have been found, which will be significant for the chemistry of chlorophylls. Finally, we have deciphered the sequence of chemical reactions that take place during the manufacturing of green food colorants and propose the whole pathway that explains the occurrence of the chlorophylls they contain.

Metabolomics of Chlorophylls and Carotenoids: Analytical Methods and Metabolome-Based Studies.

Chlorophylls and carotenoids are two families of antioxidants present in daily ingested foods, whose recognition as added-value ingredients runs in parallel with the increasing number of demonstrated functional properties. Both groups include a complex and vast number of compounds, and extraction and analysis methods evolved recently to a modern protocol. New methodologies are more potent, precise, and accurate, but their application requires a better understanding of the technical and biological context. Therefore, the present review compiles the basic knowledge and recent advances of the metabolomics of chlorophylls and carotenoids, including the interrelation with the primary metabolism. The study includes material preparation and extraction protocols, the instrumental techniques for the acquisition of spectroscopic and spectrometric properties, the workflows and software tools for data pre-processing and analysis, and the application of mass spectrometry to pigment metabolomics. In addition, the review encompasses a critical description of studies where metabolomics analyses of chlorophylls and carotenoids were developed as an approach to analyzing the effects of biotic and abiotic stressors on living organisms.

The color of greater flamingo feathers fades when no cosmetics are applied.

Greater flamingos use cosmetic coloration by spreading uropygial secretions pigmented with carotenoids over their feathers, which makes the plumage redder. Because flamingos inhabit open environments that receive direct solar radiation during daytime, and carotenoids bleach when exposed to solar radiation, we expected that the plumage color would fade if there is no maintenance for cosmetic purposes. Here, we show that the concentrations of pigments inside feathers and on the surface of feathers were correlated, as well as that there was a correlation between the concentrations of pigments in the uropygial secretions and on the surface of feathers. There was fading in color (becoming less red) in feathers that received direct solar radiation when there was no plumage maintenance, but not so in others maintained in darkness. When we controlled for the initial color of feathers, the feathers of those individuals with higher concentration of pigments on the feather surfaces were those that lost less coloration after experimental exposure of feathers to sunny conditions. These results indicate that exposure to sunlight is correlated with the fading of feather color, which suggests that individuals need to regularly apply makeup to be more colorful. These results also reinforce the view that these birds use cosmetic coloration as a signal amplifier of plumage color. This may be important in species using highly variable habitats, such as wetlands, since the conditions experienced when molting may differ from those when the signal should be functional, usually months after molting.

An Integrative Approach of an In Vitro Measurement of the Digestibility of Triacylglycerols of Human Milk.

Several studies have been published regarding the effect of different factors on the digestion of milk lipids, considering their natural structural arrangement as milk fat globules and the efficiency of the digestive enzymes in the lipolysis of such complex structures. During digestion, the lipolytic products are dispersed in vesicles and micelles, which are the source for absorption of digested lipids. Therefore, it is necessary to consider the isolation of the micellar phase from the digesta to appropriately determine the amounts and classes of lipids which are bioaccessible. This study presents an integrative approach that included an isolation procedure to separate the micellar fraction from undigested and non-micellar parts, and the distribution of digested milk lipids in micelles determined directly through chromatographic techniques. Four groups of five full term mothers donated colostrum or mature milk. Two sets of samples were analyzed directly (raw), and two sets were pasteurized and then analyzed. Our data revealed that the profile of digested milk lipids is different depending on the lactation period and processing stage, while the carbon atom number distribution of the digested triacylglycerols in the micellar fraction provides a substantial information regarding the acylglycerols species that are less available for absorption.

Development of an accurate and direct method for the green food colorants detection.

Color impression represents between 60 and 90% of the final acceptance/rejection choice made by consumers. Consequently, color additives are attribute standards for our daily life in any market and any culture. Currently, authorized natural green food colorants comprise several copper-chelated chlorophyll derivatives. Both the raw materials and the manufacturing processes for the acquisition of these green food colorants are numerous and diverse. Hence, each producer applies its own know-how to obtain 'signature' green colorant products. Indeed, the chlorophyll profile of these products is partially known and may substantially differ among batches, while their identification just by HPLC-UV-Vis is not complete. Native chlorophylls do not chelate copper. Therefore, we propose a fast and specific method for copper chlorophyll detection, as indicative (except in a few fermented foods) of probable green food colorant addition or "re-greening" with copper salts. The new method is based on the characteristic isotopic pattern of the copper chlorophyll derivatives and does not require the precise characterization of the corresponding chlorophyll structure. This accurate methodology, based on a specific HPLC-ESI/APCI-HRMS method assisted with powerful post-processing software, is versatile as it can be used for other metallo-chlorophyll complexes also applied to improve the green coloration of food products.

Effect of gestational age (preterm or full term) on lipid composition of the milk fat globule and its membrane in human colostrum.

Human colostrum is the first milk secreted by the mother after birth and constitutes the ideal food for the newborn, because its chemical composition, rich in immunoglobulins, antimicrobial peptides, growth factors, bioactive lipids, and other important molecules, is perfectly adapted to the metabolic, digestive, and immunological immaturity of the newborn. An incomplete gestational period can affect the maturity of the mammary gland and its ability to secrete milk with the proper composition for the newborn's condition. Previous studies indicate that the mammary gland modulates the profiles of bioactive lipids present in the different phases of lactation from colostrum to mature milk. Given the key role played by the polar lipids (PL) (phospho- and sphingolipids) of the milk fat globule membrane (MFGM) in the immune system and cognitive development of the newborn, it is crucial to analyze whether the content and distribution of the PL are affected by gestation period. Therefore, this study aimed to determine the milk fat globule (MFG) and MFGM lipid compositions of human colostrum samples from 20 healthy preterm and full-term mothers. Lipid characterization using chromatographic techniques (gas chromatograph mass spectrometry and HPLC-evaporative light-scattering detection) revealed differences related to length of gestation in the profiles of lipid classes and fatty acid and triacylglyceride contents of colostrum. This comparative analysis leads to noteworthy outcomes about the changing roles of the PL, considering the preterm or full-term condition. We found a lack of correlation of some PL (such as phosphatidylcholine, phosphatidylinositol, and phosphatidylserine) with the delivery term; these could be denoted as structural category lipids. However, sphingomyelin and phosphatidyl-ethanolamine exhibited trends to decrease in full-term colostrum, indicating that in the final stage of pregnancy specific accretion of some PL occurs, which should be denoted as a nutritional redistribution.

Carotenoids and Chlorophylls as Antioxidants.

Chlorophylls and carotenoids are natural pigments that are present in our daily diet, especially with the increasing tendency towards more natural and healthy behaviors among consumers. As disturbed antioxidant homeostasis capacities seem to be implicated in the progress of different pathologies, the antioxidant properties of both groups of lipophilic compounds have been studied. The objective of this review was to analyze the state-of-the-art advances in this field. We conducted a systematic bibliographic search (Web of Science™ and Scopus®), followed by a comprehensive and critical description of the results, with special emphasis on highly cited and more recently published research. In addition to an evaluative description of the methodologies, this review discussed different approaches used to obtain a physiological perspective, from in vitro studies to in vivo assays using oxidative biomarkers. From a chemical viewpoint, many studies have demonstrated how a pigment's structure influences its antioxidant response and the underlying mechanisms. The major outcome is that this knowledge is essential for interpreting new data in a metabolic networks context in the search for more direct applications to health. A promising era is coming where the term "antioxidant" is understood in terms of its broadest significance.

Accomplished High-Resolution Metabolomic and Molecular Studies Identify New Carotenoid Biosynthetic Reactions in Cyanobacteria.

Cyanobacteria and microalgae are characterized by a rich and varied profile of chlorophyll (8-20 mg/g) and carotenoid (>2.2 mg/g) pigments, being noteworthy material for natural pigment production in the food industry. We propose a systematic workflow that uses high-performance liquid chromatography (HPLC) coupled with high-resolution tandem mass spectrometry in a broadband collision-induced dissociation mode (bbCID) acquisition mode to simultaneously obtain MS and MSn spectra. Metabolomic studies showed for the first time the presence of carotenoids with 5,6-epoxy-groups (5,6-epoxy- and 5,8-furanoid ß-cryptoxanthin), carotenoids from the α-branch (5,8-furanoid-2'-3'-didehydro α-cryptoxanthin), and 2'-dehydrodeoxomyxol in cyanobacteria. To support the new findings, an in silico search retrieved the putative sequences of carotenogenic enzymes involved in the corresponding biosynthetic pathways (ZEP, NSY, CrtL-b and CrtR) in the analyzed cyanobacteria species. Consequently, high-throughput metabolomics studies assisted by molecular analysis offer a powerful tool for providing insights into the characterization of bioactive compounds and their metabolism in cyanobacteria and microalgae.

HPLC-hrTOF-MS study of copper chlorophylls: Composition of food colorants and biochemistry after ingestion.

Despite the daily consumption of copper chlorophylls (E-141i), the green food colorants in foods high in fats, there is a general need for knowledge regarding their exact composition. Consequently, we have analyzed by HPLC-ESI(+)/APCI(+)-hrTOF-MS2 the accurate composition of different commercial copper chlorophyll colorants for the first time. Data showed a favored yield of copper pheophytins from a series, while pheophytins from b series are preferentially no complexed with copper. The copper pheophytins present in the food colorants consisted mainly of three structural rearrangements. New fragmentation patterns and structural assignments have been described for several copper pheophytins. During the ingestion of copper chlorophylls, no chlorophyll derivative was present in serum nor urine except a new copper-pyroporphyrin a accumulated in a few livers. In any case, this green additive could represent the ideal food colorant, as most of the copper pheophytins are excreted in the feces showing almost no absorption of copper-chlorophylls compounds.

Profile of Chlorophyll Catabolites in Senescent Leaves of Epipremnun aureum Includes a Catabolite Esterified with Hydroxytyrosol 1-O-Glucoside.

Despite the fact that chlorophyll degradation is a physiological phenomenon occurring daily in all photosynthetic tissues, chlorophyll catabolites are not fully identified. Three new forms (1, 3, and 4) of linear chlorophyll catabolites (phyllobilins) have been characterized in senescent leaves of Epipremnun aureum with spectroscopic data. Compound 1 is a hypermodified blue fluorescent chlorophyll catabolite (hmFCC) esterified with the potent antioxidant hydroxytyrosol. The sequestration of this phenol by a chlorophyll catabolite could explain the physiological meaning of the persistence of hmFCCs in some senescent plants. Compound 3, a yellow chlorophyll catabolite (YCC) originated from the oxidation at C-15 of 1. YCCs have been identified previously and are exclusively formed in the plant vacuole from the final nonfluorescent chlorophyll catabolites (NCCs). The presence of 3 in leaves implies a new reaction in chlorophyll catabolism, as the characterization of 3 implies that YCCs can be also be oxidized in the cytosol from FCCs. Finally, phyllobilin 4 represents a new type of YCC characterized by an inflexible bicyclo glucosyl moiety linked through an intramolecular esterification of the propionic acid residue with the C-3 hydroxy group. The corresponding NCC precursor was recently identified and now the characterization of 4 shows that even this rigid structure can be further oxidized. Undoubtedly, the characterization of phyllobilins is essential to completely comprehend chlorophyll degradation.

Acquisition of Mass Spectrometry Data of Carotenoids: A Focus on Big Data Management.

Accurate determination of carotenoid profile in plant tissues and food samples requires the application of hyphenated analytical resources including HPLC with high-resolution hybrid mass spectrometers. The high analytical power of modern MS equipment means the generation of Big Data resulting from the independent and complementary physicochemical properties of the target compounds that requires a complex processing to unravel the results. The present protocol describes a complete pipeline methodology for high-throughput analysis of carotenoids based on mass spectrometry (MS). After an exhaustive extraction, the workflow includes the acquisition of HPLC-hr-MS and MS2 spectra assisted step by step by specific post-processing software.

In Vitro Digestion for Control and Monitoring of Food Effects in Relation to Micellarization Index of Carotenoids.

The multifactorial system that influences the availability of macronutrients, micronutrients, and phytoconstituents with relevant bioactivities has been assessed by in vitro digestion protocols, which have become an effective technique to support the health-through-food strategy. The measurement of the significance of food structure, food matrix, synergies and competitive effects, processing features, and even some physiological issues has created valuable scientific and technological information, and the development of harmonized protocols. Now it is possible to make further advances by applying this knowledge to obtain data regarding the potential availability of target compound(s) in the food source within a standard meal context. This protocol describes the measurement of the micellarization index of carotenoids from dietary rich sources with test meals accounting the effects of high vs. low fat and normo-, hypo-, and hypercaloric content.

Chlorophyll Oxidative Metabolism During the Phototrophic and Heterotrophic Growth of Scenedesmus obliquus.

Different cultivation strategies have been developed with the aim of increasing the production rate of microalgal pigments. Specifically, biotechnological approaches are designed to increase antioxidant metabolites as chlorophyll and carotenoids. However, although significant advances have been built up, available information regarding both the chlorophyll metabolism and their oxidative reactions in photobioreactors is scarce. To unravel such processes, the detailed chlorophyll and carotenoid fraction of Scenedesmus obliquus has been studied by HPLC-ESI/APCI-hrTOF-MS from phototrophic and heterotrophic cultures. Scenedesmus is provided with a controlled strategy of interconversion between chlorophyll a and b to avoid the formation of reactive oxygen species (ROS) at high irradiances in addition to the photoacclimation of carotenoids. Indeed, precise kinetics of 132-hydroxy- and 151-hydroxy-lactone chlorophyll metabolites shows the existence of a chlorophyll oxidative metabolism as a tool to manage the excess of energy at high light conditions. Unexpectedly, the oxidation under phototrophy favored chlorophyll b metabolites over the chlorophyll a series, while the heterotrophic conditions exclusively induced the formation of 132-hydroxy-chlorophyll a. In parallel, during the first 48 h of growth in the dark, the chlorophyll fraction maintained a promising steady state. Although future studies are required to resolve the biochemical reactions implied in the chlorophyll oxidative metabolism, the present results agree with phytoplankton metabolism.

Esterified carotenoids as new food components in cyanobacteria.

Among the nutritional properties of microalgae, this study is focused in the presence of carotenoid esters in prokaryote microalgae, an event that has not been shown so far. Three carotenoid esters that accumulate in non-stressful culture conditions are identified in Aphanotece microscopica Nägeli and Phormidum autumnale Gomont, what may provide an extra value to the quality attributes of the carotenoid profile in cyanobacteria as functional foods. In addition, new data on the carotenoid characterization added quality criteria for the identification of the esterified metabolites, enabling the monitoring of these food components. Specifically, the metabolomic approach applied to the food composition analysis, has allowed to differentiate between the esters of zeinoxanthin and ß-cryptoxanthin, which were undifferentiated to date during the MS characterization of carotenoids in other food sources. We propose a new qualifier product ion specific for zeinoxanthin ester, which it is not present in the MS2 spectrum of ß-cryptoxanthin esters.

Green Natural Colorants.

Although there is no legal and clear definition of the term "natural food colorant", the market trends, and consequently industrial and commercial interest, have turned to foods with added natural pigments. This progressive substitution of artificial colorants has faced chemical complications with some colors, with a lack of stable green hues being one of them. Several strategies have been applied for green color stabilization in processed foods, from the formation of metallochlorophylls to the microencapsulation of green pigments. However, at present, the utilization of green coloring foodstuffs, which are considered an ingredient in the EU, seems to be the more successful solution for the market. Besides those topics, the present review aims to clarify the current confusion between the different chlorophyll compounds that form part of the authorized green food colorants. In this sense, legislations from different countries are compared. Finally, and in line with current concerns, the knowledge gathered so far in relation to the absorption, distribution, metabolism and excretion of all green natural food colorants is reviewed.

Carotenoid Content in Human Colostrum is Associated to Preterm/Full-Term Birth Condition.

Factors such as lactation stage and premature and small-for-gestational conditions could lead to great inter-individual variability in the carotenoid content of human milk. The aim was to analyze the carotenoid content in colostrum and mature milk of preterm (PT) and full-term (FT) mothers to establish whether they are significantly different and, if so, the stage of lactation when the differences are established. Samples of blood, colostrum, and mature milk were collected from Spanish donating mothers who gave birth to PT or FT infants. Carotenoids from serum and milk samples were analyzed by HPLC-atmospheric pressure chemical ionization (APCI)-MS. Quantitatively, colostrum from PT mothers presented lower total carotenoid content when compared to that from FT mothers. The only exception was lutein, where levels were not different. The transition from colostrum to mature milk makes observed differences in the carotenoid content disappear, since there were no variances between PT and FT groups for both individual and total carotenoid content. The premature birth condition affects the quantitative carotenoid composition of the colostrum but has no effect on the lutein content. This fact could be related to the significant role of this xanthophyll in the development of infant retina and feasibly to cognitive function.

Bioaccessibility of Marine Carotenoids.

The benefit of carotenoids to human health is undeniable and consequently, their use for this purpose is growing rapidly. Additionally, the nutraceutical properties of carotenoids have attracted attention of the food industry, especially in a new market area, the 'cosmeceuticals.' Marine organisms (microalgae, seaweeds, animals, etc.) are a rich source of carotenoids, with optimal properties for industrial production and biotechnological manipulation. Consequently, several papers have reviewed the analysis, characterization, extraction and determination methods, biological functions and industrial applications. But, now, the bioaccessibility and bioactivity of marine carotenoids has not been focused of any review, although important achievements have been published. The specific and diverse characteristic of the marine matrix determines the bioavailability of carotenoids, some of them unique in the nature. Considering the importance of the bioavailability not just from the health and nutritional point of view but also to the food and pharmaceutical industry, we consider that the present review responds to an actual demand.

Activities, bioavailability, and metabolism of lipids from structural membranes and oils: Promising research on mild cognitive impairment.

Concomitant with increased lifespan, large segments of the population are experiencing cognitive decline, which might progress to Alzheimer's disease (AD). Currently, there is no cure for AD and, once the neurodegenerative disorders are established, patients use pharmacologic therapy to slow the progression of the symptoms and require appropriate care to manage their condition. The preclinical stage of neural degeneration that progress through mild cognitive impairment (MCI) before the onset of AD is when it might be possible to introduce behavioral changes and pharma-nutritional interventions that modify the risk factors of MCI conversion to AD. Some food components accumulate in brain tissues, where they play essential roles. Among them, polar lipids, omega 3 fatty acids, and carotenoids appear to work additively or synergistically. Therefore, there is an opportunity to formulate nutraceuticals/functional foods to slow the progression of MCI. In this paper, we review the biochemical bases and recent interventions with bioactive lipids-rich formulations. Based on accumulated evidence, we propose that appropriate large-scale trials are warranted.