Tocotrienols, tocopherols and tocomonoenols : characterization in Costa Rican palm oils, and intracellular and tissue distribution as a function of the hepatic alpha-tocopherol transfer protein

Vitamin E is a generic term for a group of micronutrients exhibiting the biological activity of alpha-tocopherol. Initially, four tocopherols (T) and four tocotrienols (T3) were recognized as the naturally occurring vitamin E compounds. The main difference among T and T3 is the 3-fold unsaturated 16-carbon side chain of the T3 compared to the saturated 16-carbon side chain of the T. Recently, a group of four vitamin E compounds with a single double bond at carbon 11 were discovered, namely tocomonoenols (T1). Edible oils are the major source of T, T3, and of T1. As a fat-soluble vitamin, the vitamin E is absorbed after oral intake and transported in the circulation to the liver, where vitamin E undergoes sorting by the action of the alpha-hepatic-tocopherol transfer protein (TTP) and the cytochrome P450 (CYP) enzymes. alpha-T is preferentially secreted into the bloodstream, while the non-alpha-T congeners are metabolized by CYP to the carboxyethylhydroxychromanols (CEHC), which are excreted via urine and feces. The TTP has been recognized as necessary for the maintenance of normal alpha-T concentrations in plasma and extrahepatic tissues. Interestingly, TTP might also protect the non-alpha-T congeners from side-chain degradation, and therefore prevent their metabolic degradation. The present thesis aimed at increasing our knowledge of the non-αT congeners of vitamin E with respect to their occurrence in food, their intracellular localization upon uptake into liver cells, and their tissue distribution in mammals. A potential role of the TTP in the intracellular and intra-organismic trafficking of the non-alpha-T congeners was a second focus of the current investigations. To this purpose, the vitamin E profiles and contents in oils of three Elaeis Guineensis, two Elaeis Oleifera, and one hybrid OxG palm fruit genotypes from Costa Rica were determined after mechanical extraction with a screw press and chemical extraction with hexane. Vitamin E profiles in the palm oils were similar, irrespective of the genotype and extraction procedure, and alpha- and gamma-T3 were the most abundant congeners. alpha-T1 was found in oils from five of the six varieties. Hexane extraction yielded up to 2.5-fold higher total vitamin E compared to screw press extraction. The two most abundant tocotrienols in the oils were selected for further studies with respect to their cellular uptake and intracellular distribution in cultured liver cells with and without stable expression of TTP and compared to their respective tocopherol counterparts. After uptake, all four congeners were primarily associated with the lysosomes, endoplasmic reticulum and plasma membrane. Overall, the results conclude that neither the structural differences between the four congeners, nor the TTP-expression are important factors behind the intracellular trafficking (uptake and distribution) of the congeners in cultured liver cells. Finally, an animal study was performed to examine the tissue distribution of alpha-T1 in mice in comparison to alpha-T. Besides was investigated the influence of TTP. Wild-type and TTP knockout mice were fed a standard diet with either alpha-T or alpha-T1 for 2 weeks. Concentrations were measured in blood and several tissues. alpha-T1 was only found in blood, not in tissues. Loss of TTP function in knockout mice resulted in almost complete depletion of alpha-T in all tissues. Interestingly, alpha-T1 was still present in blood. In conclusion, alpha-T1 reached the blood in mice with and without TTP function, suggesting that TTP may not, or only to a limited extent, be required for the secretion of alpha-T1 into the systemic circulation. Since more is known about alpha-T than the non-alpha-T congeners, new opportunities for further research on the biological activities and consequent health benefits of the non-alpha-T congeners have arisen based on the contributions of the present thesis.Vitamin E ist der Oberbegriff für eine Gruppe von Mikronährstoffen, welche die biologische Aktivität von alpha-Tocopherol aufweisen. Bisher wurden acht Kongenere, vier Tocopherole (T) und vier Tocotrienole (T3) als die natürlich vorkommenden Vitamin-E-Verbindungen klassifiziert. Die Unterscheidung zwischen T und T3 wird durch die dreifach ungesättigte 16-Kohlenstoff lange Seitenkette der T3´s im Vergleich zur gesättigten 16- Kohlenstoff langen Seitenkette der T´s definiert. Vor kurzem wurde eine Gruppe von vier Vitamin-E-Verbindungen mit einer Einfach-Doppelbindung am 11ten Kohlenstoffatom entdeckt und als Tocomonoenole (T1) bezeichnet. Speiseöle sind die Hauptquelle für T, T3 und T1. Das fettlösliches Vitamin E wird oral aufgenommen und zur Leber transportiert. In der Leber durchlaufen die Vitamin E Kongenere eine Sortierung durch das alpha-hepatischen-Tocopherol-Transferprotein (TTP) und der Cytochrom P450 (CYP)-Enzyme. Das alphaT wird bevorzugt in den Blutkreislauf abgegeben, während die nicht-alphaT-Kongenere von den CYP-Enzymen zu den Carboxyethylhydroxychromanolen (CEHC) metabolisiert und über Urin und Stuhl ausgeschieden werden. Für die Aufrechterhaltung der normalen alphaT-Konzentration in Plasma und extrahepatischem Gewebe ist das TTP daher notwendig. Interessanterweise ist es möglich, das TTP auch die nicht-alphaT-Kongenere vor dem Abbau der Seitenkette schützen und so deren metabolischen Abbau verhindern kann. Ziel dieser Arbeit war unser Wissen über die nicht-alphaT-Kongenere von Vitamin E in Bezug auf ihr Vorkommen in der Nahrung, ihre intrazelluläre Lokalisation bei der Aufnahme in Leberzellen und ihre Gewebeverteilung bei Säugetieren zu erweitern. Die potentielle Rolle des TTP bei der intrazellulären Verteilung und dem Transport im Organismus der nicht-alphaT-Kongenere war ein zweiter Schwerpunkt der aktuellen Untersuchungen. Zu diesem Zweck wurden die Vitamin-E-Profile und -Gehalte in Ölen von drei Elaeis Guineensis, zwei Elaeis Oleifera und einem hybriden OxG-Palmenfrüchte-Genotyp aus Costa Rica ermittelt. Die Öle wurden entweder mechanisch mit einer Spindelpresse oder chemisch mit Hexan extrahiert. Die Vitamin-E-Profile in den Palmölen waren unabhängig vom Genotyp und Extraktionsverfahren ähnlich, alpha- und gamma-T3 waren die häufigsten Kongenere. alpha-T1 wurde in fünf der sechs Sorten gefunden. Die Extraktion mit Hexan ergab im Vergleich zur mechanischen Spindelpresse einen bis zu 2,5-fach höheren Gesamt-Vitamin E-Gehalt. Aufgrund der aus den Ölen gewonnen Erkenntnisse bezüglich der Häufigkeit der vorkommenden nicht- alphaT-Kongenere, wurden die beiden Tocotrienole für weitere Studien auf ihre zelluläre Aufnahme und intrazelluläre Verteilung in kultivierten Leberzellen mit und ohne stabiler TTP-Expression ausgewählt und mit ihren jeweiligen Tocopherol-Gegenstücken verglichen. Nach Aufnahme der vier Kongenere waren diese hauptsächlich mit den Lysosomen, dem endoplasmatischen Retikulum und der Plasmamembran assoziiert. Zusammengefasst lassen diese Ergebnisse darauf schließen, dass weder die strukturellen Unterschiede, noch die Expression des TTP ausschlaggebende Faktoren für den intrazellulären Transport (Aufnahme und Verteilung) der Kongenere in kultivierten Leberzellen sind. Abschließend wurde eine Tierstudie durchgeführt, um die Gewebeverteilung des alphaT1 bei Mäusen im Vergleich zu alphaT untersuchen. Ebenfalls wurde hierbei der Einfluss von TTP mit berücksichtigt. Wildtyp und TTP Knockout Mäuse erhielten 2 Wochen lang eine Standarddiät mit alphaT oder alphaT1. Die Konzentrationen wurden im Blut und verschiedenen Geweben bestimmt. Das alphaT1 konnte ausschließlich im Blut, nicht in den Geweben, gefunden werden. Der Verlust der TTP-Funktion bei Knockout Mäusen führte zu einer fast vollständigen Abnahme der alphaT-Konzentrationen in allen Geweben. Interessanterweise konnte alphaT1 noch im Blut nachgewiesen werden. Das Vorhandensein von alphaT1 im Blut von Mäusen mit und ohne TTP-Funktion deutet darauf hin, dass TTP für die Sekretion von alphaT1 in den systemischen Kreislauf nicht oder nur eingeschränkt erforderlich sein könnte. Aufgrund des höheren Wissenstandes über alphaT im Vergleich zu den nicht-alphaT-Kongeneren, sind auf Grundlage der vorliegenden Arbeit neue Möglichkeiten für die weitere Erforschung der biologischen Aktivitäten und den daraus resultierenden gesundheitlichen Vorteile der nicht-alphaT-Kongenere entstanden

Vitamin E profile in rice (Oryza sativa L.) seeds grown and commercialized in Costa Rica

Introducción. El arroz (Oryza sativa L.) es uno de los cereales más consumidos a nivel mundial, las subespecies índicas y japónicas son las más cultivadas. La vitamina E presente en el arroz posee alta actividad antioxidante que contribuye a extender la longevidad de sus semillas. Su cuantificación permite conocer el aporte nutricional respecto a esta vitamina. Objetivo. Analizar el perfil de vitamina E en semillas de las subespecies de arroz (O. sativa L.) índicas (comerciales registradas, aromáticas, promisorias en desarrollo) y japónicas, consumidas en Costa Rica. Materiales y métodos. Se analizaron veintisiete materiales cultivados en las regiones Chorotega y Brunca, Costa Rica, cosechados en 2020. Se cuantificó la vitamina E por cromatografía líquida de ultra-alta resolución acoplado a detección por masas de cuadrupolo triple con fuente de ionización química a presión atmosférica, en el Centro para Investigaciones en Granos y Semillas (CIGRAS), Universidad de Costa Rica, en 2021. Resultados. En el perfil de vitamina E se obtuvo un agrupamiento característico para las muestras japónicas, opuesto al presentado por las muestras índicas. Los compuestos mayoritarios fueron γ-tocotrienol, α-tocoferol y γ-tocoferol, el rango de concentración total de vitamina E fue de 5,50 a 33,20 μg g-1, donde la subespecie japónica fue la que reportó menor cantidad (6,30 – 8,80 μg g-1), mientras que la muestra Nayuribe, perteneciente a la subespecie índica comercial registrada obtuvo la concentración más alta (33,20 ± 7,40 μg g-1). Conclusión. Aunque las subvariedades analizadas son filogenéticamente de la misma especie, las diferencias significativas encontradas en el aporte nutricional de vitamina E pueden deberse a características intrínsecas de cada subespecie. El contenido significativamente alto de vitamina E de la muestra Nayuribe evidenció que es posible encontrar acervos para alto contenido de vitamina E entre las variedades analizadas.Introduction. Rice (Oryza sativa L.) is one of the most consumed cereals worldwide, the indica and japonica subspecies are the most cultivated. The vitamin E present in rice has a high antioxidant activity that contributes to extend the longevity of its seeds. Its quantification allows to know the nutritional contribution of this vitamin. Objective. To analyze the vitamin E profile in seeds of indica (registered commercial, aromatic, promising in development) and japonica subspecies of rice (O. sativa L.), consumed in Costa Rica. Materials and methods. Twenty-seven materials grown in the Chorotega and Brunca regions of Costa Rica, harvested in 2020 were analyzed. Vitamin E was quantified by ultra-high performance liquid chromatography coupled to triple quadrupole mass detection with chemical ionization source at atmospheric pressure at the Centro para Investigaciones en Granos y Semillas (CIGRAS), Universidad de Costa Rica, in 2021. Results. In the vitamin E profile, a characteristic clustering was obtained for the japonica samples, which was opposite to that presented by the indica samples. The majority compounds were γ-tocotrienol, α-tocopherol, and γ-tocopherol, the range of total vitamin E concentration was 5.50 to 33.20 μg g-1, where the japonica subspecies reported the lowest amount (6.30 – 8.80 μg g-1), while the Nayuribe sample, belonging to the registered commercial indica subspecies, obtained the highest concentration (33.20 ± 7.40 μg g-1). Conclusion. Although the analyzed subvarieties are phylogenetically from the same species, the significant differences found in the nutritional intake of vitamin E may be due to intrinsic characteristics of each subspecies. The significantly high vitamin E content in the Nayuribe sample showed that it is possible to find stocks for a high vitamin E content among the varieties analyzed.Universidad de Costa Rica/[734-C0-213]/UCR/Costa RicaUniversidad de Costa Rica/[734-B2-060]/UCR/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Centro para Investigaciones en Granos y Semillas (CIGRAS

Contaminación del agua del río Durazno, Costa Rica: más allá del índice holandés de calidad del agua

ABSTRACT. “Pollution of the Durazno River water, Costa Rica: beyond the Dutch water quality index”. Introduction: The micro-basin of the Durazno River in Costa Rica is a source of water for human consumption, but is suspected of microbiological pollution from several land uses. Objective: To assess the water quality of the Durazno micro-basin from the physicochemical, microbiological and antibiotics points of view. Methods: We used the Dutch Water Quality index; Standard Methods for the Examination of Water and Wastewater; and solid-phase extraction and ultra-high performance liquid chromatography coupled to tandem mass spectrometry. Results: While physicochemical parameters indicated an adequate water quality, microbiologically this water is not acceptable for human consumption. The water has Doxycycline and Cefotaxime, possibly of agricultural origin. This is the first report of Cefotaxime in water from Costa Rica. The Dutch index fails to take into account microbiological parameters that are also important. Conclusion: The Durazno River does not meet the standards for human water consumption and the Dutch index needs to be complemented with microbiological parameters.    RESUMEN. Introducción: La microcuenca del río Durazno en Costa Rica es fuente de agua para consumo humano, pero se sospecha de contaminación microbiológica por varios usos del suelo. Objetivo: Evaluar la calidad del agua de la microcuenca del Durazno desde el punto de vista fisicoquímico, microbiológico y antibiótico. Métodos: Utilizamos el índice holandés de calidad del agua; Métodos Estándar para el Examen de Agua y Aguas Residuales; y extracción en fase sólida y cromatografía líquida de ultra alta resolución con espectrometría de masas en tándem. Resultados: Si bien los parámetros fisicoquímicos indicaron una calidad de agua adecuada, microbiológicamente esta agua no es aceptable para el consumo humano. El agua tiene doxiciclina y cefotaxima, posiblemente de origen agrícola. Este es el primer reporte de Cefotaxima en agua de Costa Rica. El índice holandés no tiene en cuenta parámetros microbiológicos que también son importantes. Conclusión: El río Durazno no cumple con los estándares para consumo humano de agua y el índice holandés necesita ser complementado con parámetros microbiológicos

Contaminación del agua del río Durazno, Costa Rica: más allá del índice holandés de calidad del agua

RESUMEN. Introducción: La microcuenca del río Durazno en Costa Rica es fuente de agua para consumo humano, pero se sospecha de contaminación microbiológica por varios usos del suelo. Objetivo: Evaluar la calidad del agua de la microcuenca del Durazno desde el punto de vista fisicoquímico, microbiológico y antibiótico. Métodos: Utilizamos el índice holandés de calidad del agua; Métodos Estándar para el Examen de Agua y Aguas Residuales; y extracción en fase sólida y cromatografía líquida de ultra alta resolución con espectrometría de masas en tándem. Resultados: Si bien los parámetros fisicoquímicos indicaron una calidad de agua adecuada, microbiológicamente esta agua no es aceptable para el consumo humano. El agua tiene doxiciclina y cefotaxima, posiblemente de origen agrícola. Este es el primer reporte de Cefotaxima en agua de Costa Rica. El índice holandés no tiene en cuenta parámetros microbiológicos que también son importantes. Conclusión: El río Durazno no cumple con los estándares para consumo humano de agua y el índice holandés necesita ser complementado con parámetros microbiológicos

α-Tocomonoenol Is Bioavailable in Mice and May Partly Be Regulated by the Function of the Hepatic α-Tocopherol Transfer Protein

Tocomonoenols are vitamin E derivatives present in foods with a single double bond at carbon 11’ in the sidechain. The α-tocopherol transfer protein (TTP) is required for the maintenance of normal α-tocopherol (αT) concentrations. Its role in the tissue distribution of α-11′-tocomonoenol (αT1) is unknown. We investigated the tissue distribution of αT1 and αT in wild-type (TTP+/+) and TTP knockout (TTP−/−) mice fed diets with either αT or αT1 for two weeks. αT1 was only found in blood, not tissues. αT concentrations in TTP+/+ mice were in the order of adipose tissue > brain > heart > spleen > lungs > kidneys > small intestine > liver. Loss of TTP function depleted αT in all tissues. αT1, contrary to αT, was still present in the blood of TTP−/− mice (16% of αT1 in TTP+/+). Autoclaving and storage at room temperature reduced αT and αT1 in experimental diets. In conclusion, αT1 is bioavailable, reaches the blood in mice, and may not entirely depend on TTP function for secretion into the systemic circulation. However, due to instability of the test compounds in the experimental diets, further in vivo experiments are required to clarify the role of TTP in αT1 secretion. Future research should consider compound stability during autoclaving of rodent feed

Pineapple-stover derived furan compounds as gasoline oxygenate additive

Furan compounds have properties such as oxygenate additive to enhance octane number of gasoline. The procedure was a furan synthesis through an acidic hydrolysis of the polysaccharide materials from pineapple plantation residues. The products obtained were a complex mixture of mostly 3-(2-furanyl)-2-propenoic acid, 4-(2-furanyl)-3-butene-2-one and 5-methyl-furfural. Thermodynamic and rheolgical properties of the mixture in toto were measured, as well as its oxygenating capability. The results showed a two units enhancer oxygenate additive for naphta, potentially safe for transport and handling, presenting the following characteristics: specific gravity 1,22559±0,00002, kinematic viscosity 0,0127±0,0001 Stokes, enthalpy of vaporization 39,1±0,1kJ mol-1, isothermal compressibility (1,0±0.2)10-9Pa-1, rate of evaporation 0,03±0,02g s-1 m-2 and Hildebrand solubility parameter 18,0±0,1(J cm-3)1/2.KEY WORDSPineapple crown, pineapple stubble, research octane number, oxygenate additive, furan compound, methyl terbutyl ether.  Los compuestos furánicos tienen propiedades de aditivo oxigenante que les permite incrementar el número de octano de la gasolina. Su síntesis se hizo a través de una hidrólisis ácida de los materiales a base de polisacáridos provenientes de residuos de plantaciones de piña. Los productos obtenidos eran una mezcla compleja, en su mayoría 3 - (2-furanil)-2-propenoico, 4 - (2-furanil)-3-buteno-2-ona y 5-metil-furfural. Se midieron las propiedades termodinámicas y reológicas de la mezcla en su totalidad, así como su capacidad de oxigenación. Los resultados mostraron un aditivo que incrementa en dos unidades el poder oxigenante en la nafta, que es potencialmente seguro para su transporte y manipulación, y que presenta las siguientes características: una gravedad específica de 1,22559±0,00002, una viscosidad cinemática de 0,0127±0,0001 Stokes, una entalpía de vaporización de 39,1±0,1 kJ mol-1, una compresibilidad isotérmica de (1,0±0,2)10-9Pa-1, una velocidad de evaporación de0,03±0,02g s-1 m-2y un parámetro de solubilidad de Hildebrand de 18,0±0,1(J cm-3)1/2.PALABRAS CLAVECorona de piña, rastrojos de piña, índice de octano, aditivo oxigenante, compuesto furánico, metil terbutil éter.

α-Tocopherol transfer protein does not regulate the cellular uptake and intracellular distribution of α- and γ-tocopherols and -tocotrienols in cultured liver cells

Liver cells express a cytosolic α-tocopherol transfer protein (αTTP) with high binding affinity for α-tocopherol (αT) and much lower affinities for the non-αT congeners. The role of αTTP in the intracellular distribution of the different vitamin E forms is currently unknown. We therefore investigated the intracellular localization of αT, γ-tocopherol (γT), α-tocotrienol (αT3), and γ-tocotrienol (γT3) in cultured hepatic cells with and without stable expression of αTTP. We first determined cellular uptake of the four congeners and found the methylation of the chromanol ring and saturation of the sidechain to be important factors, with tocotrienols being taken up more efficiently than tocopherols and the γ-congeners more than the α-congeners, irrespective of the expression of αTTP. This, however, could perhaps also be due to an observed higher stability of tocotrienols, compared to tocopherols, in culture media rather than a higher absorption. We then incubated HepG2 cells and αTTP-expressing HepG2 cells with αT, γT, αT3, or γT3, isolated organelle fractions by density gradient centrifugation, and determined the concentrations of the congeners in the subcellular fractions. All four congeners were primarily associated with the lysosomes, endoplasmic reticulum, and plasma membrane, whereas only αT correlated with mitochondria. Neither the chromanol ring methylation or sidechain saturation, nor the expression of αTTP were important factors for the intracellular distribution of vitamin E. In conclusion, αTTP does not appear to regulate the uptake and intracellular localization of different vitamin E congeners in cultured liver cells. Keywords: Endoplasmic reticulum, HepG2 liver cells, Intracellular localization, Lysosomes, Mitochondria, Plasma membrane, α-Tocopherol transfer protein, Tocotrienols, Trafficking, Vitamin

Carotenoids and xanthophyll esters of yellow and red nance fruits (Byrsonima crassifolia (L.) Kunth) from Costa Rica

Carotenoid profiles, by means of HPLC-PDA-MSn, and CIE-L*C*h° colour values of yellow and red nance fruits from Costa Rica were elucidated. Among 16 carotenoids detected, (all-E)-lutein was the most abundant accounting for >80% of the total carotenoids, followed by (all-E)-zeaxanthin (9–11%) and (all-E)-β-carotene (2–9%). Minor constituents were (Z)-isomers of lutein and β-carotene, as well as diverse lutein diesters. Among the esters, lutein dimyristate was the most abundant as substantiated by the comparison with a marigold flower extract. Total carotenoids in the peel (616.2 μg/100 g of FW in yellow nance and 174.2 μg/100 g of FW in red nance) were higher than in the pulp (39.4 μg/100 g of FW in yellow nance and 31.4 μg/100 g of FW in red nance). Since carotenoid profiles of yellow and red varieties were qualitatively similar, although the colour values showed significant differences (77.2 and 88.6 h° in peel and pulp of yellow nance, versus 32.7 and 67.3 h° in peel and pulp of red nance, respectively), pigments other than carotenoids may impart the colour of red nance. High lutein content renders nance fruit as a nutritionally relevant source of this micronutrient.UCR::Vicerrectoría de Docencia::Ciencias Agroalimentarias::Facultad de Ciencias Agroalimentarias::Escuela de Tecnología de AlimentosUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Instituto de Investigaciones Agrícolas (IIA)UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Centro para Investigaciones en Granos y Semillas (CIGRAS

Strawberry <i>Fragaria x ananassa</i> cv. Festival: A Polyphenol-Based Phytochemical Characterization in Fruit and Leaf Extracts

Berry fruits are an important dietary source of health-promoting antioxidant polyphenols. Interestingly, berry leaves of diverse species, including strawberries, have shown higher bioactive phytochemical content in the leaves than in the fruit. Moreover, the vegetative part of the plants is usually discarded, representing a presumably large source of underutilized bioactive biomass. In this investigation, the polyphenol profiles of tropical highland strawberry (Fragaria x ananassa cv. Festival) leaves and fruits were compared by high-performance liquid chromatography coupled with a diode array detector (UHPLC-DAD) and mass spectrometry (HPLC-MS). The total polyphenol strawberry leaf extracts exhibited a 122-fold-higher total polyphenol content and 13-fold higher antioxidant activity (ORAC) than strawberry fruits, and they showed evidence of possible photoprotective effects against UV damage in human melanoma cells (SK-MEL-28) and in murine embryo fibroblasts (NIH/3T3), together with promising anti-proliferative activities against the same melanoma cells. Seven polyphenols were confirmed by HPLC-DAD in the leaf extracts, with differences depending on fraction solubility. Moreover, three substituted quercetin derivatives, three substituted kaempferol derivatives, two anthocyanins, and catechin were confirmed in the soluble fraction by HPLC-MS. Given their higher total polyphenol content and bioactive activities, underutilized strawberry Festival leaves are a potential source of apparently abundant biomass with prospective bioactive applications

Self-Emulsifying Micellization of Crude Extracts from Apple (Malus domestica cv. Anna), Plum (Prunus domestica cv. Satsuma), and Guava (Psidium guajava L.) Fruits

Micellar microemulsions are thermodynamically stable self-emulsifying systems that have been used to successfully improve the low oral bioavailability of several bioactive phytochemicals, such as antioxidant polyphenols. However, most studies have reported the micellization of single-compounds or purified chemical fractions; thus, the stability, phytochemical-loading efficiency, and bioactivity of complex crude extracts remain largely unexplored. In this study, we evaluated the effects of micellar emulsification of tropical apple (Malus domestica cv. Anna), plum (Prunus domestica cv. Satsuma), and guava (Psidium guajava L.) extracts regarding particle size and stability, polyphenol-loading efficiency, antioxidant capacity, and cytotoxic activity in human and murine cells. Simple food-grade extraction protocols were implemented to obtain apple, plum, and guava extracts. Total polyphenols, flavonoids, and antioxidant activity (DPPH) were determined in the fruit extracts, and their polyphenol profile was further characterized by liquid chromatography (HPLC-DAD). The dried extracts were mixed into a food-grade, self-emulsifying system, and their cytotoxicity in human and murine cell lines was compared. Our research showed that complex fruit matrixes were successfully emulsified into thermodynamically stable polysorbate-based nanometric micelles with uniform size distribution and consistent pH stability, with potential applications in food and biomedical industries