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1.
Crit Rev Food Sci Nutr ; 63(20): 4655-4674, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-34839771

RESUMO

Most lipids in our diet come under the form of triacylglycerols that are often redispersed and stabilized by surfactants in processed foods. In plant however, lipid assemblies constitute interesting sources of natural bioactive and functional ingredients. In most photosynthetic sources, polar lipids rich in ω3 fatty acids are concentrated. The objective of this review is to summarize all the knowledge about the physico-chemical composition, digestive behavior and oxidative stability of plant polar lipid assemblies to emphasize their potential as functional ingredients in human diet and their potentialities to substitute artificial surfactants/antioxidants. The specific composition of plant membrane assemblies is detailed, including plasma membranes, oil bodies, and chloroplast; emphasizing its concentration in phospholipids, galactolipids, peculiar proteins, and phenolic compounds. These molecular species are hydrolyzed by specific digestive enzymes in the human gastrointestinal tract and reduced the hydrolysis of triacylglycerols and their subsequent absorption. Galactolipids specifically can activate ileal break and intrinsically present an antioxidant (AO) activity and metal chelating activity. In addition, their natural association with phenolic compounds and their physical state (Lα state of digalactosyldiacylglycerols) in membrane assemblies can enhance their stability to oxidation. All these elements make plant membrane molecules and assemblies very promising components with a wide range of potential applications to vectorize ω3 polyunsaturated fatty acids, and equilibrate human diet.


Assuntos
Galactolipídeos , Fosfolipídeos , Humanos , Galactolipídeos/metabolismo , Triglicerídeos/metabolismo , Oxirredução , Antioxidantes/metabolismo , Estresse Oxidativo
2.
Compr Rev Food Sci Food Saf ; 21(1): 642-688, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34889039

RESUMO

Lipid oxidation is a major concern in the food, cosmetic, and pharmaceutical sectors. The degradation of unsaturated lipids affects the nutritional, physicochemical, and organoleptic properties of products and can lead to off-flavors and to the formation of potentially harmful oxidation compounds. To prevent or slow down lipid oxidation, different antioxidant additives are used alone or in combination to achieve the best possible efficiency with the minimum possible quantities. In manufactured products, that is, heterogeneous systems containing lipids as emulsions or bulk phase, the efficiency of an antioxidant is determined not only by its chemical reactivity, but also by its physical properties and its interaction with other compounds present in the products. The antioxidants most widely used on the industrial scale are probably tocopherols, either as natural extracts or pure synthetic molecules. Considerable research has been conducted on their antioxidant activity, but results regarding their efficiency are contradictory. Here, we review the known mechanisms behind the antioxidant activity of tocopherols and discuss the chemical and physical features that determine their efficacy. We first describe their chemical reactivity linked with the main factors that modulate it between efficient antioxidant capacity and potential prooxidant effects. We then describe their chemical interactions with other molecules (phenolic compounds, metals, vitamin C, carotenes, proteins, and phospholipids) that have potential additive, synergistic, or antagonist effects. Finally, we discuss other physical parameters that influence their activity in complex systems including their specific interactions with surfactants in emulsions and their behavior in the presence of association colloids in bulk oils.


Assuntos
Antioxidantes , Tocoferóis , Antioxidantes/química , Antioxidantes/farmacologia , Emulsões/química , Oxirredução , Óleos de Plantas/química , Tocoferóis/química
3.
J Nat Prod ; 79(7): 1709-18, 2016 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-27312226

RESUMO

The intense red-colored Hibiscus sabdariffa flowers are an inexpensive source of anthocyanins with potential to be used as natural, innocuous, and health-beneficial colorants. An anthocyanin-rich extract from hibiscus flowers was obtained by ultrasound-assisted extraction. By a single-step process fractionation using a Sep-Pak C18 cartridge, the main hibiscus anthocyanins, delphinidin-3-O-sambubioside (Dp-samb) and cyanidin-3-O-sambubioside (Cy-samb), were separated and then characterized via NMR and HPLC-ESIMS data. Since Dp-samb was the most abundant anthocyanin identified in the extract, its colorant properties were studied by the pH jumps method, which allowed the calculation of the single acid-base equilibrium (pK'a 2.92), the acidity (pKa 3.70), and the hydration constants (pKh 3.02). Moreover, by using size-exclusion chromatography, new cyanidin-derived anthocyanins (with three or more sugar units) were successfully identified and reported for the first time in the hibiscus extract.


Assuntos
Antocianinas/isolamento & purificação , Hibiscus/química , Antocianinas/química , Cromatografia Líquida de Alta Pressão , Flores/química , Estrutura Molecular , Dióxido de Silício
4.
Biochimie ; 215: 12-23, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37062468

RESUMO

Pancreatic lipase related-protein 2 (PLRP2) exhibits remarkable galactolipase and phospholipase A1 activities, which depend greatly on the supramolecular organization of the substrates and the presence of surfactant molecules such as bile salts. The objective of the study was to understand the modulation of the adsorption mechanisms and enzymatic activity of Guinea pig PLRP2 (gPLRP2), by the physical environment of the enzyme and the physical state of its substrate. Langmuir monolayers were used to reproduce homogeneous and heterogeneous photosynthetic model membranes containing galactolipids (GL), and/or phospholipids (PL), and/or phytosterols (pS), presenting uncharged or charged interfaces. The same lipid mixtures were also used to form micrometric liposomes, and their gPLRP2 catalyzed digestion kinetics were investigated in presence or in absence of bile salts (NaTDC) during static in vitro, so called "bulk", digestion. The enzymatic activity of gPLRP2 onto the galactolipid-based monolayers was characterized with an optimum activity at 15 mN/m, in the absence of bile salts. gPLRP2 showed enhanced adsorption onto biomimetic model monolayer containing negatively charged lipids. However, the compositional complexity in the heterogeneous uncharged model systems induced a lag phase before the initiation of lipolysis. In bulk, no enzymatic activity could be demonstrated on GL-based liposomes in the absence of bile salts, probably due to the high lateral pressure of the lipid bilayers. In the presence of NaTDC (4 mM), however, gPLRP2 showed both high galactolipase and moderate phospholipase A1 activities on liposomes, probably due to a decrease in packing and lateral pressure upon NaTDC adsorption, and subsequent disruption of liposomes.


Assuntos
Lipase , Lipossomos , Animais , Cobaias , Hidrólise , Fosfolipases A1 , Adsorção , Lipase/química , Fosfolipídeos/metabolismo , Galactolipídeos , Ácidos e Sais Biliares
5.
Food Chem ; 429: 136854, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37531873

RESUMO

Fortification of infant follow-on formulas (IFF) with docosahexaenoic acid (DHA), which is prone to lipid oxidation, is required by European regulation. This study aimed to identify lipid formulation parameters that improve the nutritional profile and oxidative stability of IFF. Model IFF were formulated using different lipid and emulsifier sources, including refined (POM) or unrefined red palm oil (RPOM), coconut oil (COM), dairy fat (DFOM), soy lecithin, and dairy phospholipids (DPL). After an accelerated storage, RPOM and DFOM with DPL had improved oxidative stability compared to other IFF. Specifically, they had a peroxide value twice lower than POM and 20% less loss of tocopherols for DFOM-DPL. This higher stability was mainly explained by the presence of compounds such as carotenoids in RPOM and sphingomyelin in DFOM-DPL very likely acting synergistically with tocopherols. Incorporation of dairy lipids and carotenoids into DHA-enriched IFF compositions seems promising to enhance their stability and nutritional quality.


Assuntos
Ácidos Graxos , Fórmulas Infantis , Humanos , Lactente , Ácidos Docosa-Hexaenoicos/metabolismo , Fosfolipídeos , Óleo de Palmeira , Tocoferóis , Carotenoides/metabolismo , Estresse Oxidativo
6.
Data Brief ; 51: 109649, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37869618

RESUMO

The main objective of infant follow-on formulas, consumed from the age of 6 to 12 months, is to mimic the composition of breast milk in order to meet the nutritional needs of infant. In this context, their composition is governed in Europe by a strict regulation that has evolved in 2020 to force manufacturers to improve the nutritional profile of the formulas. The objective of this dataset was to collect the ingredient lists and nutritional values of infant follow-on formulas present on the world market with a focus on the lipid fraction. The data collection was carried out from December 2020 to April 2021 directly on the product packaging or on the websites of the different brands. Only "classic" infant follow-on formulas that are widely consumed were listed. Thus, the ingredient lists and nutritional values of 91 infant formulas were collected. The nutritional values are systematically presented for 100 g of powder, for 100 Kcal and for 100 mL of formula. The sources of fats, emulsifiers and vitamins A and E were also extracted from the ingredient lists. This dataset can be used as a tool for the formulation of infant follow-on formulas or to situate the positioning of products in relation to the market.

7.
Mol Nutr Food Res ; 67(6): e2200111, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36461912

RESUMO

SCOPE: The purpose of the study is to characterize the chemical diversity in rice bran (RB) lipidome and determines whether daily RB consumption for 4 weeks may modulate plasma lipid profiles in children. METHODS AND RESULTS: Untargeted and targeted lipidomics via ultra-performance liquid chromatography coupled with high-resolution tandem mass spectrometry (UPLC-MS/MS) are applied to identify bioactive RB lipids from a collection of 17 rice varieties. To determine the impact of RB (Calrose-USA variety) supplementation on plasma lipid profile, a secondary analysis of plasma lipidome is conducted on data recorded in a clinical study (NCT01911390, n = 18 moderately hypercholesterolemic children) before and after 4 weeks of dietary intervention with a control or RB supplemented (15 g day-1 ) snack. Untargeted lipidomic reveals 118 lipids as the core of lipidome across all varieties among which phospholipids are abundant and oxylipins present. Phytoprostanes and phytofurans are quantified and characterized. Lipidome analysis of the children plasma following RB consumption reveals the presence of polar lipids and oxylipins alongside putative modulations in endocannabinoids associated with RB consumption. CONCLUSION: The investigation of novel polar lipids, oxylipins, phytoprostanes, and phytofurans in RB extracts provides support for new health-promoting properties interesting for people at risk for cardiometabolic disease.


Assuntos
Oryza , Fosfolipídeos , Criança , Humanos , Cromatografia Líquida , Glicolipídeos , Metabolismo dos Lipídeos , Lipidômica , Oxilipinas , Fosfolipídeos/análise , Espectrometria de Massas em Tandem/métodos
8.
Colloids Surf B Biointerfaces ; 217: 112646, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35763897

RESUMO

The structural behavior of model assemblies composed of monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG), the two main galactolipids found in plants, was investigated at the air/water interface and in aqueous dispersion. To approach the composition of the natural photosynthetic membranes, tunable Langmuir model membrane of galactolipids (GL) were used, and were complexified to form either heterogenous binary or ternary assemblies of GL, phospholipids (PL), and phytosterols (pS). The impact of pS, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) or both on the structural properties of GL membrane was studied. The nature of the interactions between the different molecules was investigated using biophysical characterizations (ellipsometry, tensiometry, atomic force microscopy). In addition, the phase behavior was determined by SAXS analysis on the model assemblies in aqueous dispersions. Results revealed the good interfacial stability of these specific plant membrane lipids. The morphology of the GL film was characteristic of a fluid phase, with an interfacial roughness induced by the intercalation of monogalactosyl and digalactosyl polar heads of MGDG and DGDG, respectively. A phase heterogeneity in the monolayer was induced by the addition of DPPC and/or pS, which resulted in the modification of galactolipid organization and headgroup interactions. These structural changes were confirmed by SAXS analysis, showing more favorable interactions between MGDG and DPPC than between DGDG and DPPC in aqueous dispersion. This phenomenon was exacerbated in the presence of pS.


Assuntos
Galactolipídeos , Fitosteróis , Galactolipídeos/química , Plantas , Espalhamento a Baixo Ângulo , Água , Difração de Raios X
9.
Colloids Surf B Biointerfaces ; 220: 112933, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36279762

RESUMO

The rapid and preferential adsorption of a gastric lipase recombinant dog gastric lipase (rDGL) in heterogeneous films of phospholipids and triacylglycerols has previously been unveiled using Langmuir films analyzed by tensiometry, ellipsometry and Langmuir-Blodgett transfer coupled to atomic force microscopy. Here we invest the adsorption behavior of rDGL in heterogeneous galactolipid and mixed galactolipid-phospholipid or galactolipid-phospholipid-phytosterol films representative of plant membrane. Again rDGL, preferentially got adsorbed at the expanded lipid phases of the films underlining the genericity of such adsorption behavior. The addition of phytosterols to these mixtures resulted in the creation of defects, favoring the adsorption of rDGL at the fluid phases, but also improving the adsorption capacities of the lipase at the phase boundaries and towards the defects in the condensed phase. rDGL, like all gastric lipases, does not show any activity on galactolipids and phospholipids but its adsorption impacts their lateral organization and may change the adsorption and activity of other lipolytic enzymes in the course of digestion.


Assuntos
Galactolipídeos , Fitosteróis , Cães , Animais , Adsorção , Fosfolipídeos , Lipase , Propriedades de Superfície
10.
Biochim Biophys Acta ; 1801(4): 508-16, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20083229

RESUMO

Monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG) are the most abundant lipids in nature, mainly as important components of plant leaves and chloroplast membranes. Pancreatic lipase-related protein 2 (PLRP2) was previously found to express galactolipase activity, and it is assumed to be the main enzyme involved in the digestion of these common vegetable lipids in the gastrointestinal tract. Most of the previous in vitro studies were however performed with medium chain synthetic galactolipids as substrates. It was shown here that recombinant guinea pig (Cavia porcellus) as well as human PLRP2 hydrolyzed at high rates natural DGDG and MGDG extracted from spinach leaves. Their specific activities were estimated by combining the pH-stat technique, thin layer chromatography coupled to scanning densitometry and gas chromatography. The optimum assay conditions for hydrolysis of these natural long chain galactolipids were investigated and the optimum bile salt to substrate ratio was found to be different from that established with synthetic medium chains MGDG and DGDG. Nevertheless the length of acyl chains and the nature of the galactosyl polar head of the galactolipid did not have major effects on the specific activities of PLRP2, which were found to be very high on both medium chain [1786+/-100 to 5420+/-85U/mg] and long chain [1756+/-208 to 4167+/-167U/mg] galactolipids. Fatty acid composition analysis of natural MGDG, DGDG and their lipolysis products revealed that PLRP2 only hydrolyzed one ester bond at the sn-1 position of galactolipids. PLRP2 might be used to produce lipid and free fatty acid fractions enriched in either 16:3 n-3 or 18:3 n-3 fatty acids, both found at high levels in galactolipids.


Assuntos
Galactolipídeos/metabolismo , Lipase/metabolismo , Animais , Hidrolases de Éster Carboxílico/metabolismo , Cromatografia Gasosa , Cromatografia em Camada Fina , Ensaios Enzimáticos , Ácidos Graxos/metabolismo , Galactolipídeos/isolamento & purificação , Cobaias , Humanos , Hidrólise , Lipólise , Spinacia oleracea/química , Spinacia oleracea/metabolismo
11.
Plant Foods Hum Nutr ; 66(1): 34-40, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21267783

RESUMO

Triacylglycerol (TAG) lipases have been thoroughly characterized in mammals and microorganisms, whereas very little is known about plant TAG lipases. The lipolytic activity occurring in all the laticies is known to be associated with sedimentable particles, and all attempts to solubilize the lipolytic activity of Carica papaya latex have been unsuccessful so far. However, some of the biochemical properties of the lipase from Carica papaya latex (CPL) were determined from the insoluble fraction of the latex. The activity was optimum at a temperature of 37°C and a pH of 9.0, and the specific activities of CPL were found to be 2,000 ± 185 and 256 ± 8 U/g when tributyrin and olive oil were used as substrates, respectively. CPL was found to be active in the absence of any detergent, whereas many lipases require detergent to prevent the occurrence of interfacial denaturation. CPL was inactive in the presence of micellar concentrations of Triton X-100, sodium dodecyl sulfate (SDS) and tetradecyl trimethylammonium bromide (TTAB), and still showed high levels of activity in the presence of sodium taurodeoxycholate (NaTDC) and the zwitterionic Chaps detergent. The effects of various proteases on the lipolytic activity of CPL were studied, and CPL was found to be resistant to treatment with various enzymes, except in the presence of trypsin. All these properties suggest that CPL may be a good candidate for various biotechnological applications.


Assuntos
Carica/enzimologia , Enzimas Imobilizadas/metabolismo , Látex/química , Lipase/química , Detergentes/química , Lipólise/efeitos dos fármacos , Octoxinol/química , Azeite de Oliva , Óleos de Plantas/metabolismo , Dodecilsulfato de Sódio/química , Especificidade por Substrato , Ácido Taurodesoxicólico/química , Triglicerídeos/metabolismo , Tripsina
12.
Food Chem ; 360: 129880, 2021 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-33989883

RESUMO

Oil bodies (OB), the form of triacylglycerol storage in seeds, are interesting natural assemblies for nutritional applications. In walnuts, OB contain an important amount of polyunsaturated fatty acids that could be interesting food ingredients but may be prone to oxidation. The oxidative and interfacial behavior of walnut OB, either minimally-processed or after processing, were compared with processed complex walnut juice. The good oxidative stability of minimally-processed OB over 10 days (PV ≤ 8.4 meq O2/kg, TBARS = 1.4 mmol eq MDA/kg) and of processed walnut complex matrixes over 20 days (PV ≤ 4.8 meq O2/kg, TBARS = 1.4 mmol eq MDA/kg) was evidenced. In comparison, processing of OB promoted their oxidation. The interfacial studies led to the proposition of a new model of adsorption for minimally-processed OB that will be useful to design functional emulsion or foam in which OB act as emulsifiers.


Assuntos
Juglans/química , Gotículas Lipídicas/química , Óleos de Plantas/química , Adsorção , Emulsões , Nozes/química , Oxirredução , Água/química
13.
Metabolites ; 11(2)2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33671946

RESUMO

Rice bran (RB) corresponds to the outer layers of whole grain rice and contains several phenolic compounds (PCs) that make it an interesting functional food ingredient. PC richness is enhanced in pigmented RB varieties and requires effective ways of extraction of these compounds. Therefore, we investigated conventional and deep eutectic solvents (DES) extraction methods to recover a wide array of PCs from red and black RB. The RB were extracted with ethanol/water (60:40, v/v) and two DES (choline chloride/1.2-propanediol/water, 1:1:1 and choline chloride/lactic acid, 1:10, mole ratios), based on Generally Recognized as Safe (GRAS) components. Besides the quantification of the most typical phenolic acids of cereals, nontargeted metabolomic approaches were applied to PCs profiling in the extracts. Globally, metabolomics revealed 89 PCs belonging to flavonoids (52%), phenolic acids (33%), other polyphenols (8%), lignans (6%) and stilbenes (1%) classes. All extracts, whatever the solvents, were highly concentrated in the main phenolic acids found in cereals (37-66 mg/100 g in black RB extracts vs. 6-20 mg/100 g in red RB extracts). However, the PC profile was highly dependent on the extraction solvent and specific PCs were extracted using the acidic DES. The PC-enriched DES extracts demonstrated interesting DPPH scavenging activity, which makes them candidates for novel antioxidant formulations.

14.
Biochim Biophys Acta ; 1791(11): 1048-56, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19555778

RESUMO

An esterase (CpEst) showing high specific activities on tributyrin and short chain vinyl esters was obtained from Carica papaya latex after an extraction step with zwitterionic detergent and sonication, followed by gel filtration chromatography. Although the protein could not be purified to complete homogeneity due to its presence in high molecular mass aggregates, a major protein band with an apparent molecular mass of 41 kDa was obtained by SDS-PAGE. This material was digested with trypsin and the amino acid sequences of the tryptic peptides were determined by LC/ESI/MS/MS. These sequences were used to identify a partial cDNA (679 bp) from expressed sequence tags (ESTs) of C. papaya. Based upon EST sequences, a full-length gene was identified in the genome of C. papaya, with an open reading frame of 1029 bp encoding a protein of 343 amino acid residues, with a theoretical molecular mass of 38 kDa. From sequence analysis, CpEst was identified as a GDSL-motif carboxylester hydrolase belonging to the SGNH protein family and four potential N-glycosylation sites were identified. The putative catalytic triad was localised (Ser(35)-Asp(307)-His(310)) with the nucleophile serine being part of the GDSL-motif. A 3D-model of CpEst was built from known X-ray structures and sequence alignments and the catalytic triad was found to be exposed at the surface of the molecule, thus confirming the results of CpEst inhibition by tetrahydrolipstatin suggesting a direct accessibility of the inhibitor to the active site.


Assuntos
Carica/enzimologia , Esterases/química , Esterases/metabolismo , Látex/química , Motivos de Aminoácidos , Sequência de Aminoácidos , Eletroforese em Gel de Poliacrilamida , Esterases/antagonistas & inibidores , Esterases/isolamento & purificação , Concentração de Íons de Hidrogênio/efeitos dos fármacos , Lactonas/farmacologia , Lipase/antagonistas & inibidores , Lipólise/efeitos dos fármacos , Espectrometria de Massas , Modelos Moleculares , Dados de Sequência Molecular , Fases de Leitura Aberta/genética , Orlistate , Filogenia , Alinhamento de Sequência , Análise de Sequência de Proteína , Solubilidade/efeitos dos fármacos , Especificidade por Substrato/efeitos dos fármacos
15.
Anal Biochem ; 380(2): 282-90, 2008 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-18585362

RESUMO

Described here is a novel spectrophotometric method for estimating antioxidant capacity in a 96-well microplate using as UV probes the conjugated triene triacylglycerols (TAGs) naturally present in tung oil. The TAGs of this commercially available oil contain around 86% eleostearic acid, an octadecatrienoic acid with conjugated trienes exhibiting strong UV absorption at 273 nm. In an oil-in-water emulsion at 37 degrees C, the azo initiator 2,2'-azobis(2-amidinopropane) dihydrochloride generated a constant flux of peroxy radicals, which destroyed the conjugated trienes. The absorbance decay at 273 nm, related to oxidative degradation of conjugated triene TAGs, was monitored in the absence and presence of various concentrations of antioxidants. To validate this new method, the antioxidant capacity of four phenolic compounds (gallic acid, (-)-epicatechin, chlorogenic acid, and rosmarinic acid) was measured using an area-under-the-curve calculation and expressed as Trolox equivalents, the value for Trolox being taken as reference. The order of efficacy was found to be rosmarinic acid > chlorogenic acid approximately epicatechin>Trolox>gallic acid, which can be partially explained by the number of catecholic moieties and the polarity of these antioxidants. Moreover, the conjugated autoxidizable triene (CAT) assay provided good insight into antioxidant behavior (i.e., retarder or chain breaker). The same molecules were then analyzed in 2,2-diphenyl-1-picrylhydrazyl and fluorescein-based oxygen radical absorbance capacity assays, and the results are discussed critically with respect to those obtained with the CAT assay. This new method may constitute an easy-to-use, sensitive, and high-throughput in vitro protocol for evaluation of the antioxidant capacity of pure molecules and natural extracts in lipid oxidation.


Assuntos
Antioxidantes/química , Óleos de Plantas/química , Espectrofotometria Ultravioleta/métodos , Triglicerídeos/química , Catequina/química , Ácido Clorogênico/química , Cromanos/química , Cromatografia Líquida de Alta Pressão/métodos , Cinamatos/química , Depsídeos/química , Ácido Gálico/química , Cinética , Peroxidação de Lipídeos/efeitos dos fármacos , Microquímica/métodos , Reprodutibilidade dos Testes , Ácido Rosmarínico
16.
J Agric Food Chem ; 65(39): 8683-8690, 2017 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-28880083

RESUMO

The aim of this work was to evaluate the potential of crude lipase powders made from Adansonia grandidieri and Jatropha mahafalensis seeds for the synthesis of fatty acid alkyl esters in a solvent-free system. The influence of the nature of the alcohol, the amount of glycerol, and hydration of the powder was investigated. Results showed that the activity of these crude lipase powders was inversely proportional to the alcohol polarity and the amount of the glycerol in the reaction medium. To ensure optimum activity, A. grandidieri and J. mahafalensis powders must be conditioned to a water activity of 0.33 and 0.66. To obtain a fatty acid ethyl ester yield greater than 95% with A. grandidieri, ethanol should be introduced at an amount corresponding to a triacylglycerol to ethanol molar ratio of 2:1 every 15 h for 96 h and use 25% of preconditioned crude lipase powders (2 additions of 12.5%).


Assuntos
Biocombustíveis , Lipase/metabolismo , Sementes/enzimologia , Adansonia/enzimologia , Catálise , Esterificação , Ésteres , Etanol , Ácidos Graxos , Glicerol , Jatropha/enzimologia , Termodinâmica , Água
17.
Food Chem ; 230: 189-194, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28407900

RESUMO

Hibiscus sabdariffa flowers represent an interesting source of anthocyanins, one of the most important plant pigments, which are responsible of the intense red color of the calyces, and have potential as natural colorants for food applications. Nevertheless, anthocyanins are highly hydrosoluble and unstable compounds. On this basis, the aim of this work was to increase the lipophilicity of the hibiscus anthocyanins by lipophilization, in order to obtain amphiphilic colorants, which could be easily incorporated in lipid-rich food matrices. Octanoyl derivatives of delphinidin-3-O-sambubioside and cyanidin-3-O-sambubioside were chemically obtained for the first time, and characterized by means of HPLC-ESI-MS data.


Assuntos
Antocianinas/uso terapêutico , Dissacarídeos/química , Flores/química , Hibiscus/química , Espectrometria de Massas/métodos , Extratos Vegetais/química , Antocianinas/análise , Antocianinas/química
18.
J Agric Food Chem ; 54(7): 2726-31, 2006 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-16569067

RESUMO

The enzymatic properties of Plumeria rubra latex have been evaluated for the first time, showing a high activity in both hydrolysis and synthesis reactions, and compared to the biocatalytic behavior of babaco (Vasconcellea x Heilbornii cv.) latex. Both biocatalysts have been optimized by studying the various parameters that influence reaction kinetics. The optimum temperatures for hydrolysis reactions were 50 and 55 degrees C for babaco and Plumeria, respectively. The optimum pH for babaco latex was 7, whereas for Plumeria latex, two optimal pH values (4 and 7) were observed. With regard to esterification and acyl transfer reactions such as alcoholysis and interesterification, the influence of thermodynamic water activity on reaction yields was determined and correlated with water sorption and desorption isotherms. When babaco latex is used as a biocatalyst, optimal synthesis reaction yields are obtained when the enzymatic extract is stabilized at a water activity value of 0.38, which corresponds to a water content of 5.7%. This optimal level of hydration is located on the linear portion of the biocatalyst's sorption isotherm, where the water molecules exhibit high-energy interactions with the protein network. In synthesis reactions (esterification, alcoholysis, and interesterification) biocatalyzed by Plumeria latex, correlation between best reaction yields and water activity cannot be done. Indeed, the sorption isotherm plot has an atypical shape, indicating that water might be trapped in the latex matrix and, consequently, that the water content of the biocatalyst is highly dependent on the hydration history of the latex.


Assuntos
Apocynaceae/enzimologia , Lipase/metabolismo , Magnoliopsida/enzimologia , Extratos Vegetais/metabolismo , Acilação , Esterificação , Concentração de Íons de Hidrogênio , Hidrólise , Cinética , Lipídeos/análise , Óleos de Plantas/metabolismo , Óleo de Girassol , Temperatura , Termodinâmica
19.
J Agric Food Chem ; 64(46): 8838-8847, 2016 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-27797524

RESUMO

The aim of this work was to investigate lipase activities in crude extracts from Adansonia suarezensis, Adansonia grandidieri, Moringa drouhardii, Moringa oleifera, Jatropha mahafalensis, and Jatropha curcas seeds in ethanolysis and hydrolysis reactions. All crude extracts from germinated seeds showed both ethanolysis and hydrolysis activities. The influence of germination, the delipidation procedure, and the triacylglycerol/ethanol molar ratio on their ethanolysis activity was studied. Crude extracts of Jatropha and Adansonia seeds showed optimal activity at pH 8 with an optimum temperature of 30 and 40 °C, respectively. The study of the regioselectivity of crude extracts from J. mahafalensis and A. grandidieri seeds, which had the most active hydrolysis reaction, showed 1,3 regioselectivity in the hydrolysis reaction of vegetable oils. The crude extract from A. grandidieri seeds showed no typoselectivity, whereas the typoselectivity of the crude extract of J. mahafalensis seeds depended on the type of reaction.


Assuntos
Biocombustíveis/análise , Lipase/química , Óleos de Plantas/química , Proteínas de Plantas/química , Plantas/enzimologia , Biocatálise , Plantas/química , Estereoisomerismo , Especificidade por Substrato
20.
Food Chem ; 194: 749-57, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-26471615

RESUMO

Hibiscus sabdariffa L. is a worldwide consumed plant, principally after infusion of its dried sepals and calyces, which are usually discarded. Nevertheless, they represent a potential source of natural bioactive compounds, e.g. polyphenols, which could add value to this under-exploited plant. Protocatechuic acid (PA) was chosen as a model of the phenolic acids that can be extracted from H. sabdariffa. In order to modify PA hydrophilic character, which limits its use in lipid-rich food products, PA was esterified to C1-C18 alcohols, and the impact of lipophilization on its antioxidant activity was evaluated in both, an homogeneous (DPPH and ORAC methods) and an heterogeneous (CAT method) system. Results herein obtained showed that, depending on the grafted alkyl chain length, lipophilization could positively affect the antioxidant activity of PA in heterogeneous media; therefore, support its use as an innovative way to synthesize molecules with an improved antioxidant capacity and potential to be used as multifunctional preservatives in food.


Assuntos
Flores/química , Hibiscus/química , Hidroxibenzoatos/química , Antioxidantes/química , Extratos Vegetais/química
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