Biorefinery approach with green solvents for the valorization of Citrus reticulata leaves to obtain antioxidant and anticholinergic extracts.

Citrus reticulata L leaves are one of the main post-harvest byproduct, containing bioactive compounds, that are usually undervalued. This work describes the development of a biorefinery process based on the application of supercritical CO2 (SC-CO2) followed by ultrasonic-assisted extraction (UAE) combined with Natural Deep Eutectic Solvents (NaDES) to extract bioactive terpenoids and phenolic compounds from these leaves. Extraction temperature and pressure of SC-CO2 were optimized, obtaining the highest bioactive terpenoids content using 200 bar at 60 °C. A Box-Behnken experimental design showed that 57% of water in NaDES composed of Choline Chloride and Glycerol (1:2) as extraction solvent at 25 °C for 50 min were the optimal UAE-NaDES extraction conditions to obtain the highest bioactive phenolic content from the residue of the optimal SC-CO2 extraction. The optimum extract presented the highest bioactivity and polyphenol content determined by LC-DAD-MS compared with extracts obtained using only water or NaDES as solvent.

Cashew (Anacardium occidentale) Nut-Shell Liquid as Antioxidant in Bulk Soybean Oil.

Recently, natural antioxidants for the food industry have become an important focus. Cashew nut-shell liquid (CNSL) is composed of compounds that can act as natural antioxidants in food systems. The aim of this work was to evaluate the potential of CNSL and its components to act as natural antioxidants in a bulk oil system. CNSL was treated with calcium hydroxide to obtain two fractions [cardol/cardanols acid fraction (CCF) and anacardic acid fraction (AF)]. CNSL, FF and AF were analyzed by thin-layer chromatography and Fourier-transform infrared spectroscopy. The protective effects of CNSL, CCF and AF were tested in terms of the peroxide value of bulk soybean oil in accelerated assays and were compared against controls with and without synthetic antioxidants (CSA and CWA). CNLS, CCF, AF and CSA were tested at 200 mg/kg soybean oil by incubation at 30, 40, 50 and 60 °C for five days. The activation energy (Ea) for the production of peroxides was calculated by using the linearized Arrhenius equation. Thin-layer chromatography and Fourier-transform infrared spectroscopy revealed that (i) CNSL contained cardanols, anacardic acids, and cardols; (ii) CCF contained cardanols and cardols; and (iii) AF contained anacardic acids. CSA (Ea 35,355 J/mol) was the most effective antioxidant, followed by CCF (Ea 31,498 J/mol) and by CNSL (Ea 26,351 J/mol). AF exhibited pro-oxidant activity (Ea 8339 J/mol) compared with that of CWA (Ea 15,684 J/mol). Therefore, cardols and cardanols from CNSL can be used as a natural antioxidant in soybean oil.

Passiflora mollissima Seed Extract Induced Antiproliferative and Cytotoxic Effects on CAL 27 Spheroids.

Multicellular tumor spheroids are used as models in drug development due to their characteristics simulating in vivo tumors. Likewise, antiproliferative properties of extracts derived from fruits have been widely described. Peels and seeds can be used as a matrix to obtain different compounds. Recently, a study demonstrated the antiproliferative activity from a P. mollissima extract (PME) on human colon cancer cells; however, its effect on oral spheroids is unknown. Objective. To evaluate the antiproliferative potential of an extract obtained from P. mollissima seeds on the spheroid-type-3D culture model of CAL 27. Methods. CAL 27-spheroids were treated with three concentrations of PME (10, 50, and 100 µg/ml). After 72 hr incubation, morphology and cellular changes, cytotoxic and proapoptotic effect, gene expression, and metastasis were determined. Additionally, changes in the cell cycle phases responded to the PME concentrations. Comparisons between groups were made through a U Mann-Whitney test. Results. It was shown that 100 µg/ml PE affects CAL 27 cells proliferation grown in spheroids through cell cycle arrest and gene regulation of p53, HIF 1α, and CDH1. However, none of the treatments employed induced MMP9 gene expression. Conclusion. Our study shows that PME inhibits the growth and proliferation of oral tumor cells cultured in spheroids through the positive regulation of cell death and metastasis genes.

Neuroprotective Potential of Tamarillo (Cyphomandra betacea) Epicarp Extracts Obtained by Sustainable Extraction Process.

Tamarillo (Cyphomandra betacea (Cav.) Sendt.), or tree tomato, is a tropical fruit from the Andean region of South America; it is highly rich in vitamins, minerals, and polyphenolic compounds. In this study, extracts from tamarillo epicarp (TE) were obtained by pressurized liquid extraction (PLE), and their in-vitro neuroprotective potential was assessed. A central composite design with response surface methodology was performed to optimize PLE as a function of solvent composition and temperature. Selected response variables were extraction yield, total phenolic content (TPC), total flavonoid content (TFC), total carotenoid content (TCC), antioxidant (ABTS), and anti-inflammatory (LOX) activities, and anti-acetylcholinesterase (AChE) inhibitory capacity. According to the desirability function, the optimal conditions were 100% ethanol and 180°C with a 0.87 desirability value. Next, the anti-butyrylcholinesterase enzyme (BChE), reactive oxygen species (ROS), and reactive nitrogen species (RNS) inhibition as well as cytotoxicity in HK-2, THP-1 monocytes, and SH-5YSY neuroblastoma cell lines were studied for the TE extract obtained under optimized conditions. The optimum TE extract provided the following results: extraction yield (36.25%), TPC (92.09 mg GAE/g extract), TFC (4.4 mg QE/g extract), TCC (107.15 mg CE/g extract), antioxidant capacity (ABTS, IC50 = 6.33 mg/ml extract), LOX (IC50 = 48.3 mg/ml extract), and AChE (IC50 = 97.46 mg/ml extract), and showed no toxicity at concentration up to 120 µg/ml extract for all the tested cell lines. Finally, chemical characterization by liquid chromatography-tandem mass spectrometry (UHPLC-q-TOF-MS/MS) of the optimum TE extract exhibited an important presence of hydroxycinnamic acid derivatives and other phenolic acids as well as quercetin hexoside and rutin, as main metabolites responsible for the observed biological properties. All these results suggested that TE, which represents between 8 and 15% of the total fruit, could become a promising natural by-product with a potential "multitarget" activity against Alzheimer's disease.

Supercritical Fluid Extraction of Phenolic Compounds from Mango (Mangifera indica L.) Seed Kernels and Their Application as an Antioxidant in an Edible Oil.

Phenolic compounds from mango (M. indica) seed kernels (MSK) var. Sugar were obtained using supercritical CO2 and EtOH as an extraction solvent. For this purpose, a central composite design was carried out to evaluate the effect of extraction pressure (11-21 MPa), temperature (40-60 °C), and co-solvent contribution (5-15% w/w EtOH) on (i) extraction yield, (ii) oxidative stability (OS) of sunflower edible oil (SEO) with added extract using the Rancimat method, (iii) total phenolics content, (iv) total flavonoids content, and (v) DPPH radical assay. The most influential variable of the supercritical fluid extraction (SFE) process was the concentration of the co-solvent. The best OS of SEO was reached with the extract obtained at 21.0 MPa, 60 °C and 15% EtOH. Under these conditions, the extract increased the OS of SEO by up to 6.1 ± 0.2 h (OS of SEO without antioxidant, Control, was 3.5 h). The composition of the extract influenced the oxidative stability of the sunflower edible oil. By SFE it was possible to obtain extracts from mango seed kernels (MSK) var. Sugar that transfer OS to the SEO. These promissory extracts could be applied to foods and other products.

Foodomics evaluation of the anti-proliferative potential of Passiflora mollissima seeds.

The anti-proliferative potential of Passiflora mollissima seeds, an underexplored agri-food waste, was investigated in this work by evaluating the molecular changes induced at transcript and metabolite expression levels on HT-29 human colon cancer cells. For this purpose, a pressurized-liquid extract from P. mollissima seeds obtained under optimized conditions was used for the treatment of HT-29 cells and a multi-omics strategy applied, integrating transcriptomics and metabolomics analysis, along with viability and cell cycle assays to study the molecular mechanisms that explain the anti-proliferative activity of this fruit by-product. After treatment for 48 and 72 h, the viability of HT-29 colon cancer cells was markedly affected, whereas minor effects were observed on normal human colon fibroblast cells. The bioactive extract was shown to arrest HT-29 cells in the S and G2/M phases of the cell cycle, which might be mediated by the inactivation of the FAT10 cancer signalling pathway among other genes identified as altered in the transcriptomic analysis. In addition, cellular redox homeostasis, as well as the polyamines pathway and methionine metabolism were found to be affected as suggested from the metabolomics data. Finally, the Foodomics integration enabled the identification of genes, such as MAD2L1, involved in the polyamine and glutathione metabolism, or the inactivation of the NUPR1 transcription factor, that might be related with the alteration of the intracellular ceramide levels in response to endoplasmic reticulum stress.

An integrated approach for the valorization of mango seed kernel: Efficient extraction solvent selection, phytochemical profiling and antiproliferative activity assessment.

A novel valorization strategy is proposed in this work for the sustainable utilization of a major mango processing waste (i.e. mango seed kernel, MSK), integrating green pressurized-liquid extraction (PLE), bioactive assays and comprehensive HRMS-based phytochemical characterization to obtain bioactive-rich fractions with high antioxidant capacity and antiproliferative activity against human colon cancer cells. Thus, a two steps PLE procedure was proposed to recover first the non-polar fraction (fatty acids and lipids) and second the polar fraction (polyphenols). Efficient selection of the most suitable solvent for the second PLE step (ethanol/ethyl acetate mixture) was based on the Hansen solubility parameters (HSP) approach. A comprehensive GC- and LC-Q-TOF-MS/MS profiling analysis allowed the complete characterization of the lipidic and phenolic fractions obtained under optimal condition (100% EtOH at 150 °C), demonstrating the abundance of oleic and stearic acids, as well as bioactive xanthones, phenolic acids, flavonoids, gallate derivatives and gallotannins. The obtained MSK-extract exhibited higher antiproliferative activity against human colon adenocarcinoma cell line HT-29 compared to traditional extraction procedures described in literature for MSK utilization (e.g. Soxhlet), demonstrating the great potential of the proposed valorization strategy as a valuable opportunity for mango processing industry to deliver a value-added product to the market with health promoting properties.

Valorization of papaya (Carica papaya L.) agroindustrial waste through the recovery of phenolic antioxidants by supercritical fluid extraction.

In this work, supercritical fluid extraction (SFE) for the recovery of phenolic antioxidants from papaya agroindustrial waste (seeds) was explored, making use of neat supercritical CO2 and CO2 added with ethanol (CO2-EtOH). A full factorial design played on in order to evaluate the effect of CO2 extraction parameters (temperature between 40 and 60 °C, and pressure between 10 and 30 MPa) on yield and total phenols content (TPC), then ethanol was applied as a co-solvent and its effect on the recovery of phenolics was analyzed. The SFE was compared to the conventional extraction using ethanol. The antioxidant activity of all extracts was evaluated, and the phenolic composition in selected extracts was assessed by HPLC-ESI-MS. The highest extraction yields (21.02-26.46%) and TPC (15.34-34.23 mgGAE/g) were found in extracts obtained with CO2-EtOH and ethanol. Good and selective phenolic recovery was obtained by using CO2-EtOH, (44.81% of TPC recovered). The CO2-EtOH extracts showed high radical scavenging activity and higher antioxidant effect against lipid oxidation. Some phenolic acids and flavonoids were observed in the extracts with better antioxidants properties. The results showed that SFE is a suitable green technology for the phenolic recovery from papaya agroindustrial waste, and also an alternative for its valorization.

Integrated strategy for the extraction and profiling of bioactive metabolites from Passiflora mollissima seeds combining pressurized-liquid extraction and gas/liquid chromatography-high resolution mass spectrometry.

An integrated analytical methodology based on pressurized-liquid extraction (PLE) in two steps, followed by in vitro assays and liquid chromatography/gas chromatography coupled to high-resolution mass spectrometry (HRMS), was developed and applied for the isolation and characterization of potential bioactive metabolites from Passiflora mollissima seeds. PLE was proposed in two sequential steps: 1) recovery of the lipidic fraction using nonpolar solvents, and 2) recovery of the phenolic fraction from the defatted seeds' residue using polar solvents. Cyclohexane was selected as the most suitable extraction solvent for the seeds defatting process (20 min, 100 °C and 100 bar). PLE optimization by response surface methodology was carried out to obtain phenolics-rich extracts with the highest antioxidant activity. Optimal extraction yield (6.58%), total phenolic content (29.99 mg g-1), total flavonoids content (0.94 mg g-1) and antioxidant activity (6.94 mM trolox g-1 and EC50 of 2.66 µg mL-1) were obtained operating at 150 °C with EtOH (100%) as solvent. Untargeted and semi-targeted MS and MS/MS data-mining strategies were successfully implemented for the rapid and comprehensive profiling of the polar and lipidic PLE fractions analysed by UHPLC and GC, respectively, coupled to quadrupole time-of-flight mass spectrometry (q-TOF-MS/MS). Polyphenols-rich extracts from P. mollisima seeds were characterized for the first time applying this approach, showing a broad variety of flavonoids, genuine flavanols (e.g. (epi)fisetinidol) and abundant proanthocyanidins. This application can be considered a successful demonstration of the great potential of the proposed methodology to effectively obtain and characterize complex natural extracts with potential bioactivity, by making use of powerful integrated identification strategies to facilitate the challenging post-acquisition data processing of huge datasets generated by HRMS analysis.

Bioactive Phenolic Compounds from the Agroindustrial Waste of Colombian Mango Cultivars 'Sugar Mango' and 'Tommy Atkins'-An Alternative for Their Use and Valorization.

The aim of this study was to explore the potential of the agroindustrial waste from two Colombian mango cultivars as sources of bioactive phenolic compounds. Phenolic extracts from mango waste (peels, seed coats, and seed kernels) of 'sugar mango' and 'Tommy Atkins' cultivars were obtained. The bioactive properties of the phenolic extracts were accessed by measuring their free radical scavenging activity and antioxidant effects against lipid oxidation in food products; moreover, their antiproliferative effects against some cell lines of human cancer were explored. It is observed that the agroindustrial waste studied provides promising sources of bioactive phenolics. 'Sugar mango' waste provided extracts with the highest antioxidant effect in food products and antiproliferative activity; these extracts reduced lipid oxidation and cell growth by more than 57% and 75%, respectively. The seed kernel from 'sugar mango' supplied the extract with the best bioactive qualities; in addition, some recognized bioactive phenolics (such as mangiferin and several galloyl glucosides) were observed in this extract and related with its properties. The results obtained suggest that 'sugar mango' waste may be considered a source of bioactive phenolics, with promising uses in food and pharmaceutical products. Thus, a suitable alternative for the use and valorization of agroindustrial waste from Colombian mango cultivars is presented.

A multi-analytical platform based on pressurized-liquid extraction, in vitro assays and liquid chromatography/gas chromatography coupled to high resolution mass spectrometry for food by-products valorisation. Part 1: Withanolides-rich fractions from goldenberry (Physalis peruviana L.) calyces obtained after extraction optimization as case study.

In this work, a multi-analytical platform that allows obtaining and characterizing high-added value compounds from natural sources is presented, with a huge potential in traditional medicine, natural products characterization, functional foods, etc. Namely, the proposed multi-analytical platform is based on the combination of pressurized liquid extraction (PLE), liquid chromatography (LC) and gas chromatography quadrupole time-of-flight mass spectrometry GC-q-TOF-MS(/MS), in vitro assays and modelling tools for guiding extraction optimization. As case study, goldenberry or cape gooseberry fruit (Physalys peruviana L.) was selected. In particular, the potential of P. peruviana calyces, an important by-product of goldenberry processing, as promising source of bioactive compounds was evaluated. Selection of the most suitable solvent for PLE was based on the Hansen solubility parameters (HSP) approach using 4ß-hydroxywithanolide E (4ßHWE) and withanolide E (WE) as target compounds due to their bioactive potential. A surface response methodology was further applied for the optimization of the PLE parameters: temperature (50, 100 and 150 °C) and solvent composition (% EtOH in the mixture EtOH/EtOAc). The effects of the independent variables on extraction yield, withanolides content (4ßHWE and WE), total phenolic content (TPC), total flavonoids content (TFC) and antioxidant activity (EC50 and TEAC) were evaluated in order to obtain withanolide-rich extracts from P. peruviana calyces. The extract obtained under optimal conditions (at 125 °C and 75% EtOH v/v) exhibited satisfactory extraction yield (14.7%) and moderate antioxidant activity (with an EC50 value of 77.18 µg mL-1 and 1.08 mM trolox g-1), with 4ßHWE and WE concentrations of 8.8 and 2.3 mg g-1, respectively. LC-q-TOF-MS/MS analysis of the extract allowed the quantitation of 4ßHWE and WE and the tentative identification of several other withanolides structures. The obtained results demonstrate the great potential of this multi-analytical approach for developing valorisation strategies of food by-products under sustainable conditions, to obtain bioactive-enriched extracts with potential medicinal or health-promoting properties.

A multi-analytical platform based on pressurized-liquid extraction, in vitro assays and liquid chromatography/gas chromatography coupled to high resolution mass spectrometry for food by-products valorisation. Part 2: Characterization of bioactive compounds from goldenberry (Physalis peruviana L.) calyx extracts using hyphenated techniques.

A multi-analytical strategy for the valorisation of goldenberry calyx, a promising source of health-promoting compounds, is presented in this work. A comprehensive characterization of P. peruviana calyx extracts, obtained by an optimized pressurized liquid extraction (PLE) procedure, is developed applying first an ultra-high-performance liquid chromatography coupled to quadrupole time-of-flight tandem mass spectrometry (UPLC-ESI-q-TOF-MS/MS) method in positive and negative electrospray ionization (ESI) mode. A total of fifty-six phytochemicals, including major phenolic components, several withanolides (C28-isoprenoids) with a variety of biological activities, and a large family of anti-inflammatory sucrose esters were tentatively identified using this methodology. An integrated identification strategy based on accurate mass data obtained by high resolution mass spectrometry (HRMS), ion source fragmentation, MS/MS fragmentation patterns, generated molecular formulae and subsequent unsaturation degree calculation, along with database and bibliographic search is proposed. Isobaric withanolides-type compounds were tentatively identified or classified according to their different hydroxy and epoxy positions, on the basis of the complementary information provided by MS/MS product ion spectra obtained in both ESI+ and ESI- mode. The proposed structural elucidation approach provides a valuable contribution to the limited information available regarding the MS/MS structural analysis of withanolides in ESI(-) mode. Moreover, an alternative elucidation strategy based on deconvolution and database search was successfully applied for the phytochemical profiling analysis of the volatile fraction of P. peruviana calyx extracts by gas chromatography quadrupole time-of-flight mass spectrometry (GC-q-TOF-MS), which reveals the presence of relevant terpenoids, including phytosterols and tocopherols (Vitamin E). The results of the phytochemical characterization obtained herein demonstrates the great potential of applying integrated identification strategies to HRMS data obtained from complementary LC- and GC-q-TOF-MS(/MS) platforms, as powerful identification tools for improving our understanding on the phytochemical composition of natural extracts intended to be used in functional foods or in traditional medicine preparations.

Evaluación del efecto protector contra la oxidación lipídica de fracciones obtenidas a partir del epicarpio de tomate de árbol (Solanum betaceum Sendtn) / Evaluation of protective effect against lipid oxidation of fractions obtained from tree tomato (Solanum betaceum Sendtn) epicarp / Avaliação do efeito protetor contra oxidação lipídica de frações obtidas a partir da casca de tomate da árvore (Solanum betaceum Sendtn)

Resumen Se obtuvieron fracciones a partir del epicarpio de tomate de árbol (Solanum betaceum Sendtn) y se evaluó su efecto protector contra la oxidación lipídica en carne de res cocida (CRC). Un extracto obtenido a través de extracción supercrítica fue fraccionado empleando, a su vez, extracción en fase sólida; dichas fracciones fueron adicionadas a CRC (concentración 200 mg/kg). El efecto protector fue determinado a través de la comparación de algunos productos de oxidación y el antioxidante sintético terbutilhidroxiquinona (TBHQ, concentración 200 mg/kg). Cuatro fracciones fueron obtenidas, la fracción de mayor polaridad mostró una alta eficiencia para inhibir la oxidación lipídica en CRC, reduciendo la formación de hidroperóxidosHPL y TBARS en 100 y 98,5%, respectivamente; esta mostró una eficiencia superior a la observada para el TBHQ. Esta fracción más activa fue sometida a análisis HPLC-DAD y se identificaron algunos compuestos fenólicos: tres catequinas (epigalocatequina, epicatequina y galato de epigalocatequina) y un ácido fenólico (rosmarínico). Los resultados obtenidos permitieron evidenciar que el epicarpio de tomate de árbol es fuente de antioxidantes con efecto protector sobre CRC, alternativa de aprovechamiento y valorización para dicho residuo agroindustrial.

Abstract Fractions from tree tomato (Solanum betaceum Sendtn) epicarp were obtained and their effect against lipid oxidation in cooked beef meat (CBM) was evaluated. An extract obtained by supercritical fluids extraction was fractionated using solid phase extraction and these fractions were added to CBM (at 300 mg/kg). The protector effect against lipid oxidation was determined by measuring some lipid oxidation products and comparison against the synthetic antioxidant tert-butylhydroquinone (TBHQ at 300 mg/ kg). Four fractions were obtained, the most polar fraction showed high efficiency to reduce the lipid oxidation on CBM, this fraction reduced the LHP and TBARS formation at 100.0 and 98.5%, respectively. This fraction showed an ability to retard lipid oxidation in CRC higher than TBHQ. The fraction with the highest protector effect was analyzed for its phenolic composition by High-Performance Liquid Chromatography with Diode-Array Detection (HPLC-DAD). Three catechin (epigallocatechin, epicatechin and epigallocatechin gallate) and a phenolic acid (rosmarinic acid) were identified. The results revealed that the tree tomato epicarp is a source of antioxidants with protective effect on CBM, an alternative for the use and valorization of this agroindustrial waste.

Resumo Frações da casca de tomate de árvore (Solanum betaceum Sendtn) foram obtidas e seu efeito para retardar a oxidação dos lipídios em carne bovina cozida (CBC) foi avaliado. Um extrato obtido através da extração supercrítica foi fracionado utilizando extração em fase sólida e as frações obtidas foram adicionadas á CBC (concentração 300 mg/kg). O efeito protetor contra a oxidação dos lipídios foi determinado medindo alguns produtos de oxidação e comparando com a terbutil-hidroquinona (TBHQ, concentração 300 mg/kg). Quatro frações foram obtidas, destas, a fração de maior polaridade mostrou a maior eficiência para inibir a oxidação dos lipídios da CBC, reduzindo a formação de HPL e TBARS em 100 e 98,5%, respectivamente; mostrou uma eficiência maior da observada para TBHQ. Esta foi submetida a análise por a cromatografia líquida de alta eficiência com detector de díodos (HPLC-DAD) e foram identificados alguns compostos fenólicos: três catequinas (epigalocatequina, galato de epicatequina e galato de epigalocatequina) e um ácido fenólico (rosmarínico). Os resultados permitiram evidênciar que a casca do tomate de árvore é uma fonte de compostos antioxidantes comefeito protetor sobre a CBC, esta é uma alternativa de utilização e aproveitamento deesse resíduo agroindustrial.

On-line coupling of supercritical fluid extraction and chromatographic techniques.

This review summarizes and discusses recent advances and applications of on-line supercritical fluid extraction coupled to liquid chromatography, gas chromatography, and supercritical fluid chromatographic techniques. Supercritical fluids, due to their exceptional physical properties, provide unique opportunities not only during the extraction step but also in the separation process. Although supercritical fluid extraction is especially suitable for recovery of non-polar organic compounds, this technique can also be successfully applied to the extraction of polar analytes by the aid of modifiers. Supercritical fluid extraction process can be performed following "off-line" or "on-line" approaches and their main features are contrasted herein. Besides, the parameters affecting the supercritical fluid extraction process are explained and a "decision tree" is for the first time presented in this review work as a guide tool for method development. The general principles (instrumental and methodological) of the different on-line couplings of supercritical fluid extraction with chromatographic techniques are described. Advantages and shortcomings of supercritical fluid extraction as hyphenated technique are discussed. Besides, an update of the most recent applications (from 2005 up to now) of the mentioned couplings is also presented in this review.

Valorization of agroindustrial wastes: Identification by LC-MS and NMR of benzylglucosinolate from papaya (Carica papaya L.) seeds, a protective agent against lipid oxidation in edible oils.

In the present study we report the characterization of benzylglucosinolate (BG) isolated from papaya (Carica papaya L.) seeds. A methanolic extract was fractionated and further purified by solid phase extraction (SPE). It was analyzed by liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS), and nuclear magnetic resonance spectroscopy ((1) H and (13) C-NMR) as well, and the target compound BG was identified by these two techniques. The effect of BG on lipid oxidation in edible vegetable oil (EO) was shown by observing some lipid oxidation products (linoleic acid hydroperoxides, LHP; hexanal, HEX; nonanal, NON; thiobarbituric acid reactives species, TBARS). BG reduced lipid oxidation production in EO by over 80%, as compared to a control sample and in this way has proved to be a useful antioxidant, even more effective than some antioxidants used by food industry.

Interaction of a dietary fiber (pectin) with gastrointestinal components (bile salts, calcium, and lipase): a calorimetry, electrophoresis, and turbidity study.

An in vitro gastrointestinal model consisting of oral, gastric, and intestinal phases was used to elucidate the impact of pectin on the digestion of emulsified lipids. Pectin reduced the extent of lipid digestion, which was attributed to its binding interactions with specific gastrointestinal components. The interaction of pectin with bile salts, lipase, CaCl2, and NaCl was therefore investigated by turbidity, microstructure, electrophoresis, and isothermal titration calorimetry (ITC) at pH 7.0 and 37 °C. ITC showed that the interaction of pectin was endothermic with bile salts, but exothermic with CaCl2, NaCl, and lipase. Electrophoresis, microstructure, and turbidity measurements showed that anionic pectin formed electrostatic complexes with calcium ions, which may have decreased lipid digestion due to increased lipid flocculation or microgel formation because this would reduce the surface area of lipid exposed to the lipase. This research provides valuable insights into the physicochemical and molecular mechanisms of the interaction of pectin with gastrointestinal components that may affect the rate and extent of lipid digestion.

Impact of dietary fibers [methyl cellulose, chitosan, and pectin] on digestion of lipids under simulated gastrointestinal conditions.

A simulated in vitro digestion model was used to elucidate the impact of dietary fibers on the digestion rate of emulsified lipids. The influence of polysaccharide type (chitosan (cationic), methyl cellulose (non-ionic), and pectin (anionic)) and initial concentration (0.4 to 3.6% (w/w)) was examined. 2% (w/w) corn oil-in-water emulsions stabilized by 0.2% (w/w) Tween-80 were prepared, mixed with polysaccharide, and then subjected to an in vitro digestion model (37 °C): initial (pH 7.0); oral (pH 6.8; 10 min); gastric (pH 2.5; 120 min); and, intestinal (pH 7.0; 120 min) phases. The impact of polysaccharides on lipid digestion, ζ-potential, particle size, viscosity, and stability was determined. The rate and extent of lipid digestion decreased with increasing pectin, methyl cellulose, and chitosan concentrations. The free fatty acids released after 120 min of lipase digestion were 46, 63, and 81% (w/w) for methyl cellulose, pectin, and chitosan, respectively (3.6% (w/w) initial polysaccharide), indicating that methyl cellulose had the highest capacity to inhibit lipid digestion, followed by pectin, and then chitosan. The impact of the polysaccharides on lipid digestion was attributed to their ability to induce droplet flocculation, and/or due to their interactions with molecular species involved in lipid hydrolysis, such as bile salts, fatty acids, and calcium. These results have important implications for understanding the influence of dietary fibers on lipid digestion. The control of lipid digestibility within the gastrointestinal tract might be important for the development of reduced-calorie emulsion-based functional food products.